DESCRIPTION

ANTIREFLECTION FILM, FRONT PLATE FOR PLASMA DISPLAY PANEL USING THE SAME, PLASMA DISPLAY PANEL-DISPLAY DEVICE, AND IMAGE DISPLAY DEVICE

Technical Field

The present invention relates to an antireflection film, more specifically, relates to an antireflection film attached on the surface of image displays such as a plasma display panel (PDP), a liquid crystal display (LCD), an electroluminescence display (ELD), a cathode ray tube display (CRT), a fluorescent character display tube, and a field emission type display for the purpose of antireflection and the improvement of color reproducibility The invention further relates to a front panel for plasma display panel using the antireflection film, a display device using a plasma display panel, and an image display device.

Background Art

For the purpose of preventing contrast reduction and mirroring of images by the reflection of outer light in display devices such as a plasma display panel (PDP), a liquid crystal display (LCD), an electroluminescence display (ELD), cathode ray tube display (CRT), a fluorescent character display tube, and a field emission type display, an antireflection film is generally arranged on the outermost surface of the display devices to reduce reflectance by using the principle of optical interference. Accordingly, antireflection films are required to be difficultly adhered with stains and dusts, highly resisting to scratches, and difficult to cause film peeling and change in

external appearance.

An antireflection film can be generally manufactured by forming, on a support, a low refractive index layer having an appropriate thickness and a refractive index lower than that of the support. For realizing low reflectance, the refractive index of the material of the low refractive index layer is preferably as low as possible.

For reducing the refractive index of the material, means of (1) introducing a fluorine atom, and (2) reducing density (introduction of voids) are known, but there are tendencies in both means that the film strength is damaged and scratch resistance is lowered, so that the compatibility of low refractive index and high scratch resistance is difficult.

As the materials to give a film having low refractive index, fluorine-containing polymers are often used. As a means for curing the low refractive index fluorine-containing polymers, as disclosed in JP-A-8-92323 (The term "JP-A" as used herein refers to an "unexamined published Japanese patent application" and JP-A-2000- 17028, polymers having a hydroxyl group, etc., are generally cured with curing agents. However, curing agents and fluorine-containing polymers are not compatible in many cases, and improvement in the point of transparency and film hardness has been desired.

With respect to these problems, there is disclosed in JP-A-10-25388 a technique of partially condensing a melamine curing agent and a hydroxyl group-containing low refractive index polymer by heating in advance, and a certain degree of effect of improving the transparency of the film is recognized, but film hardness does not reach a sufficient level yet

Further, image display devices such as PDP and LCD display color images in principle by the combination of three primary colors of red, blue and green. However,

it is very difficult to make light for display ideal three primary colors (substantially impossible). For example, it is known that extra lights (the range of wavelength of from 560 to 620 nm) are included in the emission from the fluorescent substance of three primary colors in PDP. Therefore, JP-A-58-153904 and JP-A-60- 118748 propose color correction by using an optical filter absorbing the light of specific wavelength for correcting the color balance of the displayed color.

Antireflection films wherein the function of the above optical filters for color correction is incorporated are reported in JP-A-61 -188501, JP-A-5-205643 and JP-A- 10-26704. In patent literatures 6 and 7, a dye or a pigment is added to a transparent support to make the support function as a filter. In patent literature 8, a hard coat layer provided between a transparent support and an antireflection layer is colored to make the hard coat layer function as a filter.

When a transparent support or a hard coat layer is colored, the transparent support or the hard coat layer functions as a filter. However, the kinds of dyes capable of being added to a transparent support or a hard coat layer are very restricted. A transparent support is made of plastics or glass (generally plastics). A dye added to a transparent support is required of very high heat resistance of capable of resisting the temperature of the time of the manufacture of a support. A hard coat layer is generally a layer containing a crosslinked polymer. The crosslinking reaction of a polymer is carried out after coating of a layer. Many dyes are discolored by the reaction conditions for crosslinking. It is difficult to perform pertinent color correction coping with image displays with only the dyes capable of being added to a transparent support or a hard coat layer (with restricted kinds).

Disclosure of the Invention

An object of the present invention is to provide an antireflection film having a sufficient antireflection property, a high scratch resisting property, and a function of an optical filter capable of absorbing light of specific wavelength for the correction of color balance of the displayed color of an image display device. Further objects of the invention are to provide a front plate for a plasma display panel using the antireflection film, a display device using a plasma display panel, and an image display device.

(1) According to a first aspect of the present invention, an antireflection film includes: a transparent support; a hard coat layer containing at least a dye; and a low refractive index layer having a refractive index lower than that of the transparent support, the transparent support, the hard coat layer and the low refractive index layer being stacked in this order, and containing at least one of inorganic fine particles.

(2) The antireflection film as described in the item (1), wherein the dye has absorption maximum in the wavelength region of from 560 to 620 nm, and the hard coat layer contains a discoloration inhibitor selected from the group consisting of a phenol compound, a phenol-ether compound, an aniline compound, a quinone compound and a piperidine compound.

(3) The antireflection film as described in the item (1) or (2), wherein the inorganic fine particles have a surface treated with one of a hydrolyzed product of an organosilane compound and a partially condensed product thereof.

(4) The antireflection film as described in any one of the items (1) to (3), wherein the hard coat layer and the low refractive index layer contain at least one of an organosilane compound, the hydrolyzed product thereof and the partially condensed product thereof, respectively, and the content of at least one of the organosilane compound, the hydrolyzed product thereof and the partially condensed product thereof

in respective layers is 15 mass% or more.

(5) The antireflection film as described in any one of the items (1) to (4), wherein the inorganic fine particles are at least one of porous inorganic fine particles and hollow inorganic fine particles, and have a particle size of from 20 to 100 nm.

(6) The antireflection film as described in any one of the items (1) to (5), wherein the inorganic fine particles are hollow silica fine particles having the refractive index of 1.40 or less.

(7) The antireflection film as described in any one of the above items (1) to (6), wherein the hollow silica fine particles are hollow silica fine particles having a particle size of from 45 to 80 nm, and a refractive index of 1.30 or less.

(8) The antireflection film as described in any one of the above items (1) to (7), wherein the low refractive index layer is a layer formed out of a coating solution containing a fluorine-containing polymer, and the fluorine-containing polymer is copolymer (P) containing a polymeric unit derived from a fluorine-containing vinyl monomer and a polymeric unit having a (meth)acryloyl group on the side chain, and the main chain comprising carbon atoms alone.

(9) The antireflection film as described in the above item (8), wherein the copolymer (P) is represented by the following formula (1):

wherein L represents a divalent linking group having from 1 to 10 carbon atoms; m represents 0 or 1; X represents a hydrogen atom or a methyl group; A

represents a polymeric unit derived from an arbitrary vinyl monomer that may comprise a single component or may consist of a plurality of components; and x, y and z each represents mol% of each constituent, which are values satisfying 30≤x≤60, 5 ≤y≤ 70, and θ ≤ z≤ 65.

(10) The antireflection film as described in any one of the above items (1) to (9), wherein the low refractive index layer is cured in the atmosphere of oxygen concentration of 0.01% or less.

(11) The antireflection film as described in any one of the above items (1) to (10), wherein the low refractive index layer is a layer cured by a process of irradiation with an ionizing radiation in the atmosphere of oxygen concentration of 0.01% or less by heating so that the film surface temperature is 60 ⁰ C or higher.

(12) The antireflection film as described in any one of the items (1) to (11), which is used as the display for an image display device.

(13) According to a second aspect of the present invention, an image display device using the antireflection film as described in any one of the items (1) to (12).

(14) The antireflection film as described in any one of the items (1) to (12), which is used for display with a plasma display panel.

(15) According to a third aspect of the present invention, a front plate for a plasma display panel holding the antireflection film as described in any one of the items (1) to (12) and (14).

(16) According to a fourth aspect of the present invention, a plasma display panel-display device provided with the antireflection film as described in any one of the items (1) to (12) and (14) at at least one of the surface of the plasma display panel module, the front surface of the front plate, and the rear surface of the front plate

The antireflection film of the invention has a high scratch resisting property

and a function capable of correcting color balance of the displayed color of image display devices such as PDP and LCD, and at the same time a sufficient antireflection property. Further, the front plate for a plasma display panel and an image display device such as a plasma display panel-display device using the antireflection film of the invention are excellent in scratch resistance, show good color balance of displayed color, little in mirroring of outer light and background, and extremely high in visibility.

Brief Description of the Drawings

The invention disclosed herein will be understood better with reference to the following drawings of which:

Fig. 1 is a cross-sectional view showing a typical example of the construction of the antireflection film in the invention.

Best Mode for Carrying Out the Invention

The invention will be described in further detail below. Incidentally, in the specification of the invention, when numerical values represent physical values and characteristic values, the description "from (numerical value 1) to (numerical value 2)" means "(numerical value 1) or more and (numerical value 2) or less". Further, "(meth)acrylate" means "at least either acrylate or methacrylate", and this also applies to "(meth)acrylic acid". (Layer Constitution)

The antireflection film in the invention can use the following known layer constitutions.

Representative examples include, for example, the following layer constitutions.

• Transparent support/hard coat layer/low refractive index layer

• Transparent support/antiglare hard coat layer/low refractive index layer

• Transparent support/hard coat layer/high refractive index layer/low refractive index layer

• Transparent support/hard coat layer/ middle refractive index layer /high refractive index layer/low refractive index layer

• Transparent support/any of the above constituents/high refractive index layer/low refractive index layer

As the layers that may be provided between a transparent support and a layer on the surface side from the support, an antistatic layer (in the case where the reduction of surface resisting value is required from the display side, and the case where there is a problem of dust adhesion on the surface), a moisture-proof layer, an adhesion improving layer, and a rainbow irregularity (an interference irregularity) preventing layer are exemplified. An antistatic layer can also be provided at places other than the place between a support and the upper layer of the support.

A cross-sectional view typically shown in Fig. 1 is an example of the antireflection film of the invention, and antireflection film 1 has a layer constitution of transparent support 2, hard coat layer 3, and low refractive index layer 4 in this order. The refractive index of hard coat layer 3 is preferably from 1.48 to 2.00, and the refractive index of low refractive index layer 4 is preferably from 1.20 to 1.49. The hard coat layer in the invention may be a hard coat layer not having an antiglare layer or a hard coat layer having an antiglare layer. The low refractive index layer is formed as the outermost layer. (Introduction of Micropores into Constituting Layers of Antireflection Film)

In the invention, mainly for the purpose of sufficiently reducing the refractive

index of the low refractive index layer, it is preferred to introduce micropores into the layer, and the method of introduction is not especially restricted. For example, a method of generating bubbles in the layer and curing the binder to thereby perform fixation, a method of utilizing voids formed between particles by stacking of particles introduced into the layer, a method of introducing porous fine particles into the layer, and a method of introducing hollow fine particles are exemplified. Of these methods, from the point of manufacturing stability, a method of introducing porous fine particles into the layer and a method of introducing hollow fine particles are preferred.

In hollow fine particles, taking the radius of the vacancy in a particle as r,, and the radius of the shell of the particle as r _o , the rate of porosity x is expressed by the following expression (1).

The rate of porosity of hollow fine particles is preferably from lOto 60%, more preferably from 20 to 60%, and most preferably from 30 to 60%. To bring the rate of porosity of hollow fine particles into the above range is preferred in the view of the lowering of the refractive index and the maintenance of durability of the particles. (Preparing Method of Fine Particles Containing Pores)

In using these pore-containing fine particles (porous or hollow fine particles), the structure and kind of fine particles are not restricted, but porous inorganic oxide fine particles are preferred, and hollow organic polymer latexes and hollow inorganic oxide fine particles are most preferred In the case of inorganic oxide fine particles, fine particles containing aluminum oxide, silicon oxide, or tin oxide as the main component are preferred.

A preferred manufacturing method of hollow fine particles comprises a first

step of forming core particles capable of removal by post-treatment, a second step of forming shell layers, a third step of dissolving the core particles, and, if necessary, as a fourth step of forming an additional shell phase. Specifically, hollow fine particles can be manufactured according to the manufacturing method of hollow silica fine particles disclosed in JP-A-2001-233611

A preferred manufacturing method of porous particles comprises a first step of forming porous core particles by controlling the degrees of hydrolysis and condensation of alkoxide, and the kinds and amounts of coexisting materials, and a second step of forming shell layers on the surface of the core particles. Specifically, porous particles can be manufactured according to the methods disclosed in JP-A- 2003-327424, JP-A-2003-335515, JP-A-2003-226516 and JP-A- 2003-238140 (Measurement of Particle Size of Pore-Containing Fine Particles)

The measurement of the size of the pore-containing fine particles in the invention was performed by the observation of particles with a transmission electron microscope, and computed by averaging the circle corresponding diameter of 1,000 particles The diameter is preferably from 20 to 100 nm, more preferably from 35 to 100 nm, and still more preferably from 45 to 80 nm. When the particle size is too small, the rise of the refractive index and the increase of adsorbed moisture are observed and not preferred, while when the particle size is too large, scattering in film increases when an antireflection film is formed and not preferred.

The pore-containing fine particles in the invention may have size distribution, and the variation coefficient is preferably from 5 to 60%, and more preferably from 10 to 50% Two or three or more kinds of particles having different average particle size can be used as mixture. (Measurement of Refractive Index of Pore-Containing Fine Particles)

The refractive index of the pore-containing fine particles preferably used in the invention is preferably from 1.15 to 1.40, more preferably from 1.15 to 1.35, and most preferably from 1.18 to 1.30. The refractive index of the pore-containing fine particles can be obtained according to the following method.

(1) Preparation of liquid containing matrix-forming components

A mixed solution containing 55 g of tetraethoxysilane (TEOS) (the concentration of SiO ₂ : 28 mass%), 200 g of ethanol, 1.4 g of concentrated nitric acid, and 34 g of water was stirred at room temperature for 5 hours. A liquid (M-I) containing matrix-forming components in which the amount of ethanol was adjusted so that the concentration in terms of SiO ₂ was 5 mass% was prepared.

(2) Manufacture of film

A coating solution for measuring a refractive index was prepared by mixing Liquid (M-I) containing matrix-forming components and pore-containing fine particles so that the mass ratio in terms of oxide [matrix (SiO ₂ )/pore-containing fine particles (MO _x + SiO ₂ )] became 100/0, 90/10, 80/20, 60/40, 50/50, or 25/75. Here, an inorganic compound other than silica is expressed as MO _x . Each coating solution was coated on a silicon wafer the surface of which was maintained at 50 ⁰ C by spinner coating at 300 rpm, the coated solution was then subjected to heat treatment at 16O ⁰ C for 30 minutes, and the refractive index of each film formed for the measurement of a refractive index was measured with an ellipsometer.

(3) Computation of refractive index

After that, the obtained refractive indexes and the mixing ratios of particles {particles (MO _x + SiO ₂ )/[ρarticles (MO _x + SiO ₂ ) + matrix (SiO ₂ )]) were plotted, and the refractive index at the time of the particles (MO _x + SiO ₂ ) were 100% was found by extrapolation. When the ratio of the pore-containing fine particles is too large, there

are cases where voids are generated in the film for measurement and the refractive index of the film lowers, so that samples having a high ratio of pore-containing fine particles and deviating from amount dependency were excluded (Surface Treatment Method of Pore-Containing Fine Particles)

In the next place, the surface treatment method of pore-containing fine particles (porous or hollow inorganic fine particles) is described In order to improve the dispersibility in the binder for a low refractive index layer containing the later-described alkyl fluoride moiety and/or dimethylsiloxane moiety, it is preferred for the surfaces of inorganic fine particles to be treated with the hydrolyzed product of the organosilane compound represented by the following formula (2) and/or the partially condensed product thereof, and it is more preferred that either an acid catalyst or a metal chelating compound, or both, be used in the treatment (Organosilane Compound)

Organosilane compounds for use in the invention are described in detail below

(R") _m - Sj(X) ₄ _ _m (2)

In formula (2), R ¹⁰ represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group As the examples of the alkyl groups, a methyl group, an ethyl group, a propyl group, an isopropyl group, a hexyl group, a t-butyl group, a sec-butyl group, a hexyl group, a decyl group, and a hexadecyl group are exemplified The alkyl group preferably has from 1 to 30 carbon atoms, more preferably from 1 to 16, and especially preferably from 1 to 6 As the examples of the aryl groups, a phenyl group and a naphthyl group are exemplified, and preferably a phenyl group

X represents a hydroxyl group or a group capable of hydrolysis. As the group capable of hydrolysis, e.g., an alkoxyl group (preferably an alkoxyl group having from 1 to 5 carbon atoms, e.g., a methoxy group, an ethoxy group, etc.), a halogen atom (e.g., Cl, Br, I, etc.), and an R ² COO group (R ² preferably represents a hydrogen atom or an alkyl group having from 1 to 5 carbon atoms, e.g., a CH ₃ COO group, a C ₂ HsCOO group, etc.) are exemplified, preferably an alkoxyl group, and especially preferably a methoxy group or an ethoxy group. m represents an integer of from 1 to 3. When a plurality of R ¹⁰ or X are present, the plurality of R ¹⁰ or X may be the same or different, m is preferably 1 or 2, and especially preferably 1.

The substituents contained in R ¹⁰ are not especially restricted, and as the examples of the substituents, a halogen atom (e.g., a fluorine atom, a chlorine atom, a bromine atom, etc.), a hydroxyl group, a mercapto group, a carboxyl group, an epoxy group, an alkyl group (e.g., a methyl group, an ethyl group, an i-propyl group, a propyl group, a t-butyl group, etc.), an aryl group (e.g., a phenyl group, a naphthyl group, etc.), an aromatic heterocyclic group (e.g., a furyl group, a pyrazolyl group, a pyridyl group, etc.), an alkoxyl group (e.g., a methoxy group, an ethoxy group, an i-propoxy group, a hexyloxy group, etc.), an aryloxy group (e.g., a phenoxy group, etc.), an alkylthio group (e.g., a methylthio group, an ethylthio group, etc.), an arylthio group (e.g., a phenylthio group, etc.), an alkenyl group (e.g., a vinyl group, a 1-propenyl group, etc.), an acyloxy group (e g , an acetoxy group, an acryloyloxy group, a methacryloyloxy group, etc.), an alkoxycarbonyl group (e.g., a methoxycarbonyl group, an ethoxycarbonyl group, etc.), an aryloxycarbonyl group (e.g., a phenoxycarbonyl group, etc.), a carbamoyl group (e.g., a carbamoyl group, an N-methyl- carbamoyl group, an N,N-dimethylcarbamoyl group, an N-methyl- N-octylcarbamoyl group, etc.), and an

acylamino group (e.g., an acetylamino group, a benzoylamino group, an acrylamino group, a methacrylamino group, etc.) are exemplified, and these substituents may further be substituted. Incidentally, in the specification of the invention, even if the one that substitutes a hydrogen atom is a single atom, it is dealt with as a substituent for convenience.

When there are present a plurality of R ¹⁰ , it is preferred that at least one of them be a substituted alkyl group or a substituted aryl group. It is preferred for the substituted alkyl group or the substituted aryl group to further have a vinyl polymerizable group, and in this case, the compound represented by formula (2) can be expressed as organisilane compound having a vinyl polymerizable substituent represented by the following formula (3).

In formula (3), R ¹ represents a hydrogen atom, a methyl group, a methoxy group, an alkoxycarbonyl group, a cyano group, a fluorine atom, or a chlorine atom. As the alkoxycarbonyl group, a methoxycarbonyl group and an ethoxycarbonyl group are exemplified. R ¹ preferably represents a hydrogen atom, a methyl group, a methoxy group, a methoxycarbonyl group, a cyano group, a fluorine atom, or a chlorine atom, more preferably a hydrogen atom, a methyl group, a methoxycarbonyl group, a fluorine atom, or a chlorine atom, and especially preferably represents a hydrogen atom or a methyl group

Y represents a single bond, an ester group, an amido group, an ether group, or a urea group, preferably a single bond, an ester group, or an amido group, more

preferably a single bond or an ester group, and especially preferably represents an ester group.

L represents a divalent linking chain, specifically a substituted or unsubstituted alkylene group, a substituted or unsubstituted arylene group, a substituted or unsubstituted alkylene group having a linking group (e.g., an ether group, an ester group, an amido group) in the molecule, or a substituted or unsubstituted arylene group having a linking group in the molecule, preferably represents a substituted or unsubstituted alkylene group having from 2 to 10 carbon atoms, a substituted or unsubstituted arylene group having from 6 to 20 carbon atoms, or an alkylene group having a linking group in the molecule and from 3 to 10 carbon atoms, more preferably an unsubstituted alkylene group, an unsubstituted arylene group, or an alkylene group having an ether linking group or an ester linking group in the molecule, and especially preferably an unsubstituted alkylene group, or an alkylene group having an ether linking group or an ester linking group in the molecule. As the examples of the substituents, a halogen atom, a hydroxyl group, a mercapto group, a carboxyl group, an epoxy group, an alkyl group, and an aryl group are exemplified, and each of these substituents may further have a substituent. n represents 0 or 1. When there are present a plurality of X, the plurality of X may be the same or different n is preferably 0.

R ¹⁰ has the same meaning as R ¹⁰ in formula (2), and preferably represents a substituted or unsubstituted alkyl group or an unsubstituted aryl group, and more preferably an unsubstituted alkyl group or an unsubstituted aryl group.

X has the same meaning as X in formula (2), and preferably represents a halogen atom, a hydroxyl group or an unsubstituted alkoxyl group, more preferably a chlorine atom, a hydroxyl group, or an unsubstituted alkoxyl group having from 1 to 6

carbon atoms, still more preferably a hydroxyl group or an alkoxyl group having from 1 to 3 carbon atoms, and especially preferably a methoxy group.

An organosilane compound represented by the following formula (4) is also preferably used in the invention:

(Rf - U ) _n - S ₁ (X' )^ (4)

In formula (4), Rf represents a straight chain, branched or cyclic fluorine-containing alkyl group having from 1 to 20 carbon atoms, or a fluorine-containing aromatic group having from 6 to 14 carbon atoms. Rf preferably represents a straight chain, branched or cyclic fluoroalkyl group having from 3 to 10 carbon atoms, and more preferably represents a straight chain fluoroalkyl group having from 4 to 8 carbon atoms. L ¹ represents a divalent linking group having 10 or less carbon atoms, preferably an alkylene group having from 1 to 10 carbon atoms, and more preferably an alkylene group having from 1 to 5 carbon atoms. The alkylene group is a straight chain or branched, substituted or unsubstitutetd alkylene group that may have a linking group (e.g., ether, ester, amido) in the molecule. The alkylene group may have a substituent, e.g , a halogen atom, a hydroxyl group, a mercapto group, a carboxyl group, an epoxy group, an alkyl group, and an aryl group are exemplified as preferred substituents. X ¹ has the same meaning as X in formula (2), and preferably represents a halogen atom, a hydroxyl group, or an unsubstituted alkoxyl group, more preferably a chlorine atom, a hydroxyl group, or an unsubstituted alkoxyl group having from 1 to 6 carbon atoms, still more preferably a hydroxyl group or an alkoxyl group having from 1 to 3 carbon atoms, and especially preferably a methoxy group

The fluorine-containing silane coupling agent represented by formula (4) is

preferably a fluorine-containing silane coupling agent represented by the following formula (5):

C _n F _2n+I - (CH ₂ ) _m - Si(X ² ), (5)

In formula (5), n represents an integer of from 1 to 10, and m represents an integer of from 1 to 5. n is preferably from 4 to 10, and m is preferably from 1 to 3. X represents a methoxy group, an ethoxy group, or a chlorine atom.

The compounds represented by formulae (2) to (5) may be used in combination of two or more. The specific examples of the compounds represented by formulae (2) to (5) are shown below, but the invention is not restricted to these compounds.

M-40 NH ₂ CH ₂ CH ₂ CH ₂ Si(OCH ₃ )3

M-41 HS-CH ₂ CH ₂ CH ₂ Si(OCH ₃ J ₃

M-42 CH ₃ Si(OCH ₃ J ₃

M-43 CH ₃ Si(OC ₂ Hg) ₃

M-44 C ₂ H ₅ Si(OCH ₃ ) ₃

M-45 t-C ₄ H ₉ Si(OCH ₃ ) ₃

M-49 (CH ₃ ) ₃ SiOCH ₃

M-50 (CH ₃ ) ₃ SiCI

M-51 (CH ₃ ) ₃ SiNHSi(CH ₃ ) ₃

M-52 C ₁₈ H ₃₇ Si(OCH ₃ ) ₃

M-55 C ₃ H ₇ CH ₂ CH ₂ Si(OC ₂ H ₅ ) ₃

C ₆ F ₁₃ CH ₂ CH ₂ Si(OCH ₃ ) ₃ M-56 C ₆ F ₁₃ CH ₂ CH ₂ CH ₂ Si(OCH ₃ ) ₃ M-66

C4F ₉ CH2CH ₂ SI(OCH3)3 M-57 C^ ₉ CH ₂ CH ₂ CH ₂ Si(OCH ₃ ) ₃ M-67

C ₈ F ₁₇ CH ₂ CH ₂ Si(OCH ₃ ) ₃ M-58 C ₈ F ₁₇ CH2CH ₂ CH ₂ CH ₂ Si(OCH3)3 M-68

C ₆ F ₁₃ CH ₂ CH ₂ Si(OC ₂ H ₅ ) ₃ M-59 C ₆ F ₁₃ CH ₂ Si(OC ₂ H ₅ ) ₃ M-69

C ₈ F ₁₇ CH ₂ CH ₂ Si(OC ₂ H ₅ ) ₃

M-6O C ₈ F ₁₇ CH ₂ CH ₂ Si(OC ₄ H ₉ ) ₃

M-70

C ₄ F ₉ CH ₂ CH ₂ Si(OC ₂ H ₅ ) ₃ M-61 C ₄ F ₉ CH ₂ CH ₂ CH ₂ Si(OCH ₃ ) ₃ M-71

C ₆ F ₁₃ CH ₂ CH ₂ SiCI ₃ M-62 C ₆ F ₁₃ CH ₂ CH ₂ Si(OCH ₃ ) ₂ Br M-72

C ₈ F ₁₇ CH ₂ CH ₂ SiCI ₃ M-63 C ₈ F ₁₇ CH ₂ CH ₂ CH ₂ Si(OCH ₃ ) ₂ CI M-73

C ₄ F ₉ CH ₂ CH ₂ SiCI ₃ C ₄ F ₉ CH ₂ CH ₂ Si(CH ₃ ) ₂ OCH ₃ M-74

C ₆ F ₁₃ CH ₂ CH ₂ Si(OCH ₃ ) ₂ CH ₃ M-65 C ₆ F ₁₃ CH ₂ CH ₂ Si(OCH ₃ )CI ₂ M-75

(CF ₃ ) ₂ CFCF ₂ CF ₂ CH ₂ CH ₂ Si(OCH ₃ )3 M-76

(C ₄ F ₉ ) ₂ CFCH ₂ CH ₂ Si(OCH ₃ )3 _M -77

(C ₆ F _{1 S} ) ₂ CFCH ₂ CH ₂ Si(OCHa) ₃ M-78

(CF ₃ ) ₃ CCF ₂ CH ₂ CH ₂ Si(OCH ₃ ) ₃

M-79

(C ₄ F ₉ ) ₃ CCH ₂ CH ₂ Si(OCH ₃ ) _{3 M 8Q}

(CFa) ₂ CFOCH ₂ CH ₂ CH ₂ Si(OC ₂ Hs) _{3 M} . ₈₁

(CF ₃ )ZCFOCH ₂ CH ₂ CH ₂ SiCI _{3 M} _ ₈₂

H(CF ₂ ) ₆ CH ₂ Si(OCH ₃ ) ₃ M-83

H(CF ₂ ) ₄ CH ₂ Si(OCH ₃ ) _{3 M} _ ₈₄

H(CF ₂ ) ₈ CH ₂ Si(OCH ₃ ) _{3 M g5}

Of these specific examples, Compounds (M-I), (M-2), (M-30), (M-35), (M-49), (M-51), (M-56) and (M-57) are especially preferred. Compounds A, B and C described in Reference Example in Japanese Patent 3474330 are also excellent in dispersing stability and preferred. The use amount of the organosilane compounds represented by formulae (2) to (5) in the invention is not especially restricted, but preferably from 1 to 300 mass% against total weight of inorganic fine particles, more preferably from 3 to 100 mass%, and most preferably from 5 to 50 mass%. The amount per molar concentration on hydroxyl basis of the surface of inorganic oxide is preferably from 1 to 300 mol%, more preferably from 5 to 300 mol%, and most preferably from 10 to 200 mol%.

When the use amount of the organosilane compound is in the above range, sufficient stabilization of the dispersion can be obtained, and the film strength in film coating also rises. It is also preferred to use a combination of a plurality of the organosilane compounds, and a plurality of compounds can be added at the same time, or the addition time can be staggered to react. Further, when a plurality of compounds are partially condensed in advance and then added, the reaction control is easy and preferred.

In the invention, the dispersibility of inorganic fine particles can be improved by interacting the hydrolyzed product of the organosilane compound and/or the partially condensed product thereof on the surfaces of the inorganic fine particles.

It is preferred that the hydrolysis condensation reaction is performed by adding from 0.3 to 2.0 mol of water, preferably from 0 5 to 1.0 mol, to 1 mol of the hydrolyzing group (X, X ¹ , X ² ) and stirring in the presence of an acid catalyst or a metal chelating compound for use in the invention at 15 to 100 ⁰ C. (Catalyst for Improving Treatment of Dispersibility)

It is preferred that the improvement of dispersibility by the hydrolyzed product of the organosilane compound and/or the condensation reaction product thereof is carried out in the presence of a catalyst. As the examples of the catalysts, inorganic acids, e.g., a hydrochloric acid, a sulfuric acid, a nitric acid, etc.; organic acids, e.g., an oxalic acid, an acetic acid, a formic acid, a methanesulfonic acid, a toluenesulfonic acid, etc.; inorganic bases, e.g., sodium hydroxide, potassium hydroxide, ammonia, etc.; organic bases, e.g., triethylamine, pyridine, etc.; and metal alkoxides, e.g., triisopropoxy- aluminum, tetrabutoxyzirconium, etc.; are exemplified, and from the points of manufacturing stability and preservation stability of an inorganic oxide fine particle solution, acid catalysts (inorganic acids and organic acids) and/or metal chelating compounds are used in the invention. In inorganic acids, a hydrochloric acid and a sulfuric acid, and in organic acids, those having an acid dissociation constant (a pKa value (25 ⁰ C)) in water of 4.5 or less are preferred, more preferably a hydrochloric acid, a sulfuric acid, and organic acids having an acid dissociation constant in water of 3.0 or less, still more preferably a hydrochloric acid, a sulfuric acid, and organic acids having an acid dissociation constant in water of 2.5 or less, still further preferably organic acids having an acid dissociation constant in water of 2.5 or less, yet further preferably a methanesulfonic acid, an oxalic acid, a phthalic acid, and a malonic acid, and especially preferably an oxalic acid.

In the case where the hydrolyzing group of the organosilane compound is an alkoxyl group and the acid catalyst is an organic acid, the addition amount of water can be reduced for the carboxyl group or the sulfo group of organic acids to supply proton. The addition amount of water per mol of the alkoxide group of organosilane is from 0 to 2 mols, preferably from 0 to 1.5 mols, more preferably from 0 to 1 mol, and especially preferably from 0 to 0.5 mols. When alcohol is used as a solvent, it is also

preferred not to substantially add water.

In the invention, as the metal chelating compound for use in the improving treatment of dispersibility by the hydrolyzed product of an organosilane compound and/or the condensation reaction product thereof, it is preferred to use at least a kind of metal chelating compound having a metal selected from Zr, Ti and Al as a central metal, and, as ligands, an alcohol represented by R ³ OH (where R ³ represents an alkyl group having from 1 to 10 carbon atoms) and a compound represented by R ⁴ COCH ₂ COR ⁵ (where R ⁴ represents an alkyl group having from 1 to 10 carbon atoms, and R ⁵ represents an alkyl group having from 1 to 10 carbon atoms or an alkoxyl group having from 1 to 10 carbon atoms).

As the metal chelating compound, compounds having a metal selected from Zr, Ti and Al as a central metal can be preferably used with no particular restriction. Two or more kinds of metal chelating compounds may be used in combination if they are in the above range. The specific examples of the metal chelating compounds include zirconium chelating compounds, e.g., tri-n-butoxyethylacetoacetatezirconium, di-n-butoxyb is- (ethylacetoacetate)zirconium, n-butoxytris(ethy laceto- acetate)zirconium, tetrakis(n-propylacetoacetate)zirconium, tetrakis(acetylacetoacetate)zirconium, and tetrakis(ethyl- acetoacetate)zirconium; titanium chelating compounds, e.g., diisopropoxy-bis(ethylacetoacetate)titanium, diisopropoxy- bis(acetylacetate)titanium, and diisopropoxy-bis(acetyl- acetone)titanium; and aluminum chelating compounds, e.g , diisopropoxyethylacetoacetatealuminum, diisopropoxyacetyl- acetonatoaluminum, isopropoxybis(ethylacetoacetate)aluminum, isopropoxybis(acetylacetonato)aluminum, tris(ethylaceto- acetate)aluminum, tris(acetylacetonato)aluminum, and monoacetylacetonato-bis(ethylacetoacetate)aluminum.

Of these metal chelating compounds, preferred compounds are tri-n-butoxyethylacetoacetatezirconium, diisopropoxy- bis(acetylacetonato)titanium, diisopropoxyethylaceto- acetatealuminum, and tris(ethylacetoacetate)aluminum. These metal chelating compounds can be used alone, or two or more compounds may be used as mixture. The partially hydrolyzed products of these metal chelating compounds can also be used. (Dispersant)

In the invention, for dispersing inorganic fine particles in a solvent from powder, a dispersant can be used. Dispersants having an anionic group are preferably used in the invention.

As the anionic groups, groups having an acid proton, e.g., a carboxyl group, a sulfonic acid group (sulfo), a phosphoric acid group (phosphono), a sulfonamido group, etc., or salts thereof are preferred, a carboxyl group, a sulfonic acid group, a phosphoric acid group, or salts thereof are more preferred, and a carboxyl group and a phosphoric acid group are especially preferred. For further bettering dispersibility, dispersants may have a plurality of anionic groups. The number of anionic groups is preferably 2 or more on average, more preferably 5 or more, and especially preferably 10 or more. Further, a plurality of kinds of anionic groups may be contained in one molecule of a dispersant.

Dispersants can further contain crosslinking or a polymerizable functional group. As the crosslinking or polymerizable functional groups, ethylenic unsaturated groups capable of addition reaction and polymerization reaction by radicals (e.g., a (meth)acryloyl group, an allyl group, a styryl group, a vinyloxy group, etc.), cationic polymerizable groups (e.g., an epoxy group, an oxetanyl group, a vinyloxy group, etc.), polycondensation reactive groups (e.g., a hydrolyzable silyl group, an N-methylol

group, etc.), etc., are exemplified, and a functional group having an ethylenic unsaturated group is preferred.

(Materials for Low Refractive Index Layer)

The materials preferably used in a low refractive index layer in the invention are described below. It is preferred for the low refractive index layer of the antireflection film in the invention to be formed by coating a curable composition containing the pore-containing fine particles, drying and curing.

In the invention, in view of reducing the refractive index of the low refractive index layer to thereby lower the reflectance of the antireflection film, the following polymers having an alkyl fluoride moiety are preferably used as the components of the curable composition.

As the fluorine-containing vinyl monomers for the introduction of an alkyl fluoride moiety, fluoroolefins (e.g., fluoroethylene, vinylidene fluoride, tetrafluoroethylene, hexafluoropropylene, etc.), partially or completely fluorinated alkyl ester derivatives of (meth)acrylic acid (e.g , Viscoat 6FM, manufactured by Osaka Organic Chemical Industry Ltd., and R-2020 (a trade name), manufactured by Daikin Industries Ltd.), and completely or partially fluorinated vinyl ethers are exemplified. Of these monomers, perfluoroolefins are preferred, and hexafluoropropylene is especially preferred from the aspects of refractive index, solubility, transparency and availability. Refractive index can be reduced by the increment of the composition ratio of these fluorine-containing vinyl monomers, but film strength is lowered. In the invention, it is preferred to introduce fluorine-containing monomers so that the fluorine content of the copolymer is from 20 to 60 mass%, more preferably from 25 to 55 mass%, and especially preferably from 30 to 50 mass%.

It is preferred that polymers having an alkyl fluoride moiety have a repeating unit having a (meth)acryloyl group on the side chain as the essential constituent. By increasing the compositional ratio of the repeating unit having a (meth)acryloyl group, the film strength is heightened, but the refractive index also rises. Although it differs with the kinds of the repeating units derived from fluorine-containing vinyl monomers, it is generally preferred that the repeating unit having a (meth)acryloyl group account for 5 to 90 mass%, more preferably from 30 to 70 mass%, and especially preferably from 40 to 60 mass%.

The polymer having an alkyl fluoride moiety can also be arbitrarily copolymerized with vinyl monomers other than the repeating unit derived from a fluorine-containing vinyl monomer and the repeating unit having a (meth)acryloyl group on the side chain from various viewpoints, such as the adhesion to a substrate, Tg of the polymer (contributable to film hardness), solubility in a solvent, transparency, a sliding property, a dustproof property, an antifouling property, etc. These vinyl monomers may be used in combination of two or more according to purposes. The vinyl monomers are preferably introduced into the copolymer in sum total of from 0 to 65 mol%, more preferably in the range of from 0 to 40 mol%, and especially preferably from 0 to 30 mol%.

The vinyl monomer units that can be used in combination are not especially restricted and, for example, olefins (e.g., ethylene, propylene, isoprene, vinyl chloride, vinylidene chloride, etc.), acrylic esters (e.g., methyl acrylate, ethyl acrylate, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate), methacryliς esters (e.g., methyl methacrylate, ethyl methacrylate, butyl methacrylate, 2-hydroxyethyl methacrylate, etc.), styrene derivatives (e.g., styrene, p-hydroxymethylstyrene, p-methoxystyrene, etc.), vinyl ethers (e.g., methyl vinyl ether, ethyl vinyl ether, cyclohexyl vinyl ether,

hydroxyethyl vinyl ether, hydroxybutyl vinyl ether, etc.), vinyl esters (vinyl acetate, vinyl propionate, vinyl cinnamate, etc.), unsaturated carboxylic acids (e.g., acrylic acid, methacrylic acid, crotonic acid, maleic acid, itaconic acid, etc.), acrylamides (e.g., N,N-dimethylacryl- amide, N-tert-butylacrylamide, N-cyclohexylacrylamide, etc.), methacrylamides (e.g., N,N-dimethylmethacrylamide), and acrylonitrile are exemplified.

The copolymer for use in the invention is preferably represented by the following formula (1).

In formula (1), L represents a divalent linking group having from 1 to 10 carbon atoms, more preferably a linking group having from 1 to 6 carbon atoms, and especially preferably a linking group having from 2 to 4 carbon atoms, which may be a straight chain, branched, or cyclic structure, and may have a hetero atom selected from O, N and S.

The preferred examples of linking groups include *-(CH ₂ ) ₂ -O-**, *-(CH ₂ ) ₂ -NH-**, *-(CH ₂ ) ₄ -O-**, *-(CH ₂ ) ₆ -O-**, *-(CH ₂ ) ₂ -O-(CH ₂ ) ₂ -O-**, *-CONH-(CH ₂ ) ₃ -O-**, "'-CH ₂ CH(OH)CH ₂ - O-** and *-CH ₂ CH ₂ OCONH(CH ₂ ) ₃ -O-** (* represents the linking position on the side of the main chain pf the polymer, and ** represents the linking position on the side of the (meth)acryloyl group side), m represents 0 or 1.

In formula (1), X represents a hydrogen atom or a methyl group. A

hydrogen atom is more preferred from the viewpoint of curing reactivity.

In formula (1), A represents a repeating unit derived from an arbitrary vinyl monomer, and the repeating unit is not especially restricted so long as it is the constituent of a monomer copolymerizable with hexafluoropropylene, and the repeating unit can be optionally selected considering, e.g., adhesion to a substrate, Tg of the polymer (contributable to film hardness), solubility in a solvent, transparency, a sliding property, a dustproof property, an antifouling property, etc. The repeating unit may comprise one or two or more vinyl monomers according to purpose.

The preferred examples of the vinyl monomers include vinyl ethers, e.g., methyl vinyl ether, ethyl vinyl ether, t-butyl vinyl ether, cyclohexyl vinyl ether, isopropyl vinyl ether, hydroxyethyl vinyl ether, hydroxybutyl vinyl ether, glycidyl vinyl ether, allyl vinyl ether, etc., vinyl esters, e.g , vinyl acetate, vinyl propionate, vinyl butyrate, etc., (meth)acrylate, e.g., methyl (meth)acrylate, ethyl (meth)- acrylate, hydroxyethyl (meth) acrylate, glycidyl (meth)- acrylate, allyl (meth)acrylate, (meth)acryloyloxypropyl- trimethoxysilane, etc., styrene derivatives, e.g., styrene, p-hydroxymethylstyrene, etc., unsaturated carboxylic acids, e.g., crotonic acid, maleic acid, itaconic acid, etc., and derivatives of these carboxylic acids. More preferably vinyl ether derivatives and vinyl ester derivatives, and especially preferably vinyl ether derivatives are exemplified. x, y and z represent mol% of respective constituting components, which respectively represent the values that satisfy 30≤x≤60, 5 ≤y≤70 and 0≤z≤65, preferably 35 ≤x≤55, 30≤y≤60 and 0≤z≤20, and particularly preferably 40≤x≤ 55, 40≤y≤ 55 and 0≤z≤ 10.

As the copolymer preferably used in the invention, a compound represented by the following formula (6) can be exemplified.

General Formula 6

In formula (6), X, x and y each has the same meaning as in formula (1), and the preferred ranges are also the same. n is an integer of 2≤=n≤ 10, preferably 2≤n≤6, and especially preferably 2 ≤n≤4.

B represents a repeating unit derived from an arbitrary vinyl monomer, which may be a single composition or may be constituted of a plurality of compositions. As the examples thereof, the same examples as described in A in formula (1) are applied to zl and z2 represent mol% of respective repeating units to the entire constituting repeating units of the polymer of formula (6), which respectively satisfy the values 0≤zl ≤65 and 0≤z2≤65, preferably 0≤zl ≤30 and 0≤z2≤ 10, and especially preferably O≤zl ≤ 10 and 0≤z2≤5.

The copolymer represented by formula (1) or (6) can be synthesized by introducing a (meth)acryloyl group to a copolymer comprising, e.g., hexafluoropropylene component and hydroxyalkyl vinyl ether component in accordance with the above method.

As preferred examples of the copolymers useful in the invention, the polymers disclosed in JP-A-2004-45462, paragraphs [0043] to [0048] are exemplified.

The copolymers for use in the invention can be synthesized in accordance with the method disclosed in JP-A-2004-45462, paragraphs [0079] to [0082]

As the material for constituting a low refractive index layer, curing compositions containing the pore-containing fine particles of the invention and the later-described film-forming binder (e.g., a monomer having 2 or more ethylenic unsaturated groups) are also preferably used.

In place of, or in addition to, a polymer having an alkyl fluoride moiety and a monomer having two or more ethylenic unsaturated groups that is used as a film-forming binder, a crosslinking functional group may be introduced into the polymer by using a monomer having a crosslinking functional group to thereby cause reaction of the crosslinking functional group and introduce the crosslinking structure into the binder polymer.

The examples of the crosslinking functional groups include an isocyanate group, an epoxy group, an aziridine group, an oxazoline group, an aldehyde group, a carbonyl group, a hydrazine group, a carboxyl group, a methylol group, and an active methylene group. A vinylsulfonic acid, an acid anhydride, a cyanoacrylate derivative, melamine, etherified methylol, ester, urethane, and metal alkoxide, e.g., tetramethoxysilane can also be used as the monomers for the introduction of a crosslinking structure. Functional groups showing a crosslinking property as a result of decomposition reaction, such as a blocked isocyanate group may also be used. That is, in the invention, crosslinking functional groups may be those that show reactivity as a result of decomposition, even if they do not show reactivity at once.

By coating these binder polymers having crosslinking functional groups and then heating, a crosslinking structure can be formed.

The monomers having a crosslinking functional group may be reacted with the polymer to form a crosslinking polymer before coating of an antireflection film, but they can be crosslinked with the polymer for the first time after coating to thereby

form a matrix.

It is preferred for the hard coat layer and the low refractive index layer constituting the antireflection film of the invention to contain an organosilane compound and/or the hydrolyzed product thereof and/or the partially condensed product thereof, i.e., a sol component (hereinafter the description of "sol component" is used) in respective coating solutions. In particular, while maintaining a moderate condition of curing of the hard coat layer so as to restrain the discoloration of the dye contained in the hard coat layer on one hand, and for revealing sufficient scratch resistance on the other hand, the content of the sol component in respective layers of the hard coat layer and the low refractive index layer is preferably 15 mass% or more at the same time.

The content of the sol component in the hard coat layer and the low refractive index layer is preferably from 15 to 50 mass% of the total solids content, more preferably from 15 to 30 mass%, and most preferably from 15 to 20 mass%.

For reconciling a scratch resisting property and an antireflection performance, it is preferred for the low refractive index layer to contain an organosilane compound, the hydrolyzed product thereof, and the partially condensed product thereof, and for the hard coat layer to contain an organosilane compound, and either the hydrolyzed product or partially condensed product thereof, or the mixture thereof. After coating a coating solution, the sol component is condensed in drying and heating processes to thereby form a cured product and become the binder of the hard coat layer. When the cured product has a polymerizable unsaturated bond, a binder having a three dimensional structure is formed by irradiation with actinic ray

In the synthesis of the sol component of the organosilane compound, the organosilane compound, and the acid as catalyst and/or the metal chelating compound

used in the improvement of the dispersibility of inorganic oxide fine particles can be used.

As binders that can be preferably used in the invention besides the above photo- or heat-curable binders, the hydrolyzed products of the organosilane compounds represented by formulae (2) to (6) and/or the partially condensed products thereof can be exemplified. In the light of refractive index reduction, it is preferred for the organosilane compounds to have an alkyl fluoride moiety. The examples of preferred binders are disclosed in JP-A-2002-202406, JP-A-2002-265866 and JP-A-2002-317152.

It is preferred for the coating solutions of the hard coat layer and the low refractive index layer for use in the invention to contain a β-diketone compound and/or a β-keto ester compound in addition to the composition containing the hydrolyzed product of an organosilane compound and/or the partially condensed product thereof and the metal chelating compound.

These compounds are further described below.

The compounds used in the invention are β-diketone compounds and/or β-keto ester compounds represented by formula R ⁴ COCH ₂ COR ⁵ , and these compounds contribute to the improvement of stabilization of the composition for use in the invention. That is, it is thought that by coordinating with the metal atom in the above metal chelating compound (zirconium, titanium and/or aluminum compounds), the compounds restrain the function of acceleration of condensation reaction of the hydrolyzed product of an organosilane compound and/or the partially condensed product thereof by the metal chelating compound to thereby improve the preservation stability of a composition to be obtained R ⁴ and R ⁵ constituting the β-diketone compounds and/or β-keto ester compounds have the same meaning as R ⁴ and R ⁵

constituting the metal chelating compounds as described above.

The specific examples of the β-diketone compounds and the β-keto ester compounds include acetylacetone, methyl acetoacetate, ethyl acetoacetate, n-propyl acetoacetate, i-propyl acetoacetate, n-butyl acetoacetate, sec-butyl acetoacetate, t-butyl acetoacetate, 2,4-hexanedione, 2,4-heptanedione, 3,5-heptanedione, 2,4-octanedione, 2,4-nonanedione, 5-methylhexanedione, etc. Of these compounds, ethyl acetoacetate and acetylacetone are preferred, and acetylacetone is especially preferred. These β-diketone compounds and/or β-keto ester compounds can be used alone, or two or more compounds can be used as mixture. In the invention, β-diketone compounds and β-keto ester compounds are used preferably in an amount of 2 mols or more per mol of the metal chelating compound, and more preferably from 3 to 20 mols. When the amount is less than 2 mols, the preservation stability of a composition to be obtained is inferior, and is not so preferred. (Addition of component for lowering surface free energy)

From the viewpoint of the improvement of an antifouling property, it is preferred in the invention to lower the surface free energy of the antireflection film surface. Specifically, it is preferred to use a fluorine-containing compound and a compound having a dialkylsiloxane moiety in the low refractive index layer. As the additives having a polysiloxane structure having a dialkylsiloxane moiety, it is also preferred to add reactive group-containing polysiloxane (e.g., X-22-174DX, X-22-2426, X-22-164B, X-22-164C, X-22-170DX, X-22-176D, and X-22-1821 (trade names, manufactured by Shin-Etsu Chemical Co., Ltd.), ■ FM-0725, FM-7725, FM-4421, FM-5521, FM6621, and FM-1121 (trade names, manufactured by Chisso Corporation), and DMS-U22, RMS-033, RMS-083, UMS- 182, DMS-H21, DMS-H31, HMS-301, FMS121, FMS123, FMS 131, FMS141, and FMS221 (trade names,

manufactured by Gelest)) Further, the silicone compounds disclosed in Tables 2 and 3 in JP-A-2003-112383 can also be preferably used These polysiloxanes are preferably added in the range of from 0.1 to 10 mass% of the total solids content of the low refractive index layer, and especially preferably from 1 to 5 mass%.

It is also preferred to provide an antifouling layer of the silane coupling agent containing a perfluoroether group as disclosed in JP-A-2002-277604. (Curing of Low Refractive Index Layer)

The composition for the low refractive index layer in the invention generally takes the form of a solution containing the copolymer as the essential constituent, and is manufactured by dissolving various additives and a radical polymerization initiator in an appropriate solvent, according to necessity The concentration of solids content is arbitrarily selected according to purpose, and is generally from 0.01 to 60 mass% or so, preferably from 0.05 to 50 mass%, especially preferably from 0.1 to 20 mass%, and most preferably from 1 to 10 mass%.

Curing of the low refractive index layer of the invention can be performed by irradiation with ionizing radiation or heating in the presence of a photo-radical initiator or a thermal radical initiator, and it is especially preferred to perform curing by irradiation with ionizing radiation in the presence of a photo-radical initiator

As the examples of the photo-radical initiators, oxime esters, acetophenones, benzoins, benzophenones, phosphine oxides, ketals, anthraquinones, thioxanthones, azo compounds, peroxides, 2,3-dialkyldione compounds, disulfide compounds, fluoroamine compounds, aromatic sulfoniums, lophine dimers, onium salts, borate salts, active esters, active halogens, inorganic complexes, and coumarins are exemplified

The examples of the oxime esters include 4-phenyl-

sulfanylbenzaldoxime-0-acetate, and 2,4-dimethyl-6-methyl- sulfanylbenzaldoxime-O-benzoate.

The examples of the acetophenones include 2,2-diethoxy- acetophenone, p-dimethylacetophenone, 1-hydroxydimethyl phenyl ketone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl- 4'-(methylthio)-2-moφholinopropiophenone, and 2-benzyl-2- (dimethylamino)-4'-morpholinobutyrophenone.

The examples of the benzoins include benzoinbenzene- sulfonate, benzointoluenesulfonate, benzoin methyl ether, benzoin ethyl ether, and benzoin isopropyl ether.

The examples of the benzophenones include benzophenone, 2,4-dichlorobenzophenone, 4,4-dichlorobenzophenone, and p-chlorobenzophenone.

The examples of the phosphine oxides include 2,4,6- trimethylbenzoyldiphenyl phosphine oxide.

The examples of the onium salts include aromatic diazonium salt, aromatic iodonium salt, and aromatic sulfonium salt.

The examples of the borate salts include ion complexes with cationic dyestuffs. The examples of the active esters include 1,2-octanedione, 1 -[4-(phenylthio)-2-(o-benzoyl- oxime)], sulfonic esters, cyclic active ester compounds and the like.

As the examples of the active halogens, s-triazine and oxathiazole compounds are known, and the examples include

2-(p-methoxyphenyl)-4,6-bis(trichloromethyl)-s-triazine,

2-(p-styrylphenyl)-4,6-bis(trichloromethyl)-s-triazine, 2-[3-Br-4-di(ethyl acetate)amino]phenyl-4,6-bis(trichloro- methyl)-s-triazine, and

2-trihalomethyl-5-(p-methoxy- phenyl)- 1, 3, 4-oxadiazole.

The examples of the inorganic complexes include bis(cyclopentadienyl)bis[2,6-difluoro-3-(lH-pyrrol-l-yl)- phenyl]titanium.

The examples of the coumarins include 3-ketocoumarin.

Oxime esters and acetophenones are especially preferably used.

Various examples of photo-radical polymerization initiators are also described in Saishin UV Koka Gijutsu (The Latest Technology of UV Curing), p. 159, publisher: Kazuhiro Takasusuki, published by Gijutsu Joho Kyokai (1991), and these compounds can be used in the invention.

As commercially available photo-cleavage type photo- radical polymerization initiators, Irgacure 651, 184 and 907 (manufactured by Ciba Specialty Chemicals Inc) can be preferably used in the invention.

Photo-polymerization initiators are preferably used in an amount of from 0.1 to 15 mass parts per 100 mass parts of the polyfunctional monomer, and more preferably from 1 to 10 mass parts.

A photo-sensitizer may be used in addition to a photo- polymerization initiator. The specific examples of photo- sensitizers include n-butylamine, triethylamine, tri-n- butylphospine, Michler's ketone and thioxanthone.

It is preferred that the curing reaction of the low refractive index layer in the invention with a photo-radical polymerization initiator be performed in the atmosphere of oxygen concentration of 0.01% or less. By performing the curing reaction in the atmosphere of oxygen concentration of 0.01% or less, polymerization inhibiting reaction by oxygen can be conspicuously restrained, so that a low refractive index layer sufficiently excellent in physical strength can be formed even when the curing conditions (e.g., the dose of ionizing radiation) are set at moderate conditions.

The curing reaction is preferably performed in the atmosphere of oxygen

concentration of 0.005% or less, the atmosphere of oxygen concentration of 0.003% or less is more preferred, and the atmosphere of oxygen concentration of 0.001% or less is most preferred.

As a means for bringing oxygen concentration to 0.01% or less, it is preferred to substitute the atmospheric air (nitrogen concentration of about 79% and oxygen concentration of about 21%) with another gas, and the substitution with nitrogen (nitrogen purge) is especially preferred.

Irradiation of ionizing radiation is preferably performed with a high pressure mercury lamp and a metal halide lamp. The energy of irradiation should be sufficient that the dose does not cause the discoloration of the dye contained in the hard coat layer and curing reaction satisfactorily advances. Specifically, the dose of the range of from 50 to 1,000 mJ/cm ² is preferred, from 50 to 700 mJ/cm ² is more preferred, and the range of from 100 to 500 mJ/cm ² is especially preferred.

The temperature of the film surface in irradiation with ionizing radiation to advance curing reaction is preferably as high as possible, but in practice the temperature of the least upper bound is determined from the point of the heat resistance of the dyes contained in the transparent support and the hard coat layer. Specifically, the temperature is preferably in the range of from 60 to 120 ⁰ C, more preferably from 70 to 110 ⁰ C, and especially preferably from 80 to 100 ⁰ C.

For sufficiently advancing the curing reaction, it is preferred to maintain the film under the atmosphere of oxygen concentration of 0.01% or less for a while after irradiation of ionizing radiation. The time required for the curing reaction to satisfactorily proceed should be sufficient, specifically preferably 0.1 seconds or more, more preferably 0.3 seconds or more, and especially preferably 0.5 seconds or more. (Physical Properties of Low Refractive Index Layer)

The refractive index of the low refractive index layer is preferably from 1.20 to 1.49, more preferably from 1.25 to 1.40, and especially preferably from 1.25 to 1.38.

The thickness of the low refractive index layer is preferably from 50 to 200 nm, and more preferably from 70 to 120 nm.

The haze of the low refractive index layer is preferably 3% or less, more preferably 2% or less, and most preferably 1% or less.

The specific strength of the low refractive index layer is preferably H or higher by the pencil test in accordance with J1S-K-5600-5-4, more preferably 2H or higher, and most preferably 3 H or higher.

For the purpose of improving an antifouling property of optical films, the contact angle of the surface to water is preferably 90° or more, more preferably 95° or more, and especially preferably 100° or more. (Hard Coat Layer)

The hard coat layer in the invention is described below.

As the binders for forming the hard coat layer of the invention, polymers having a saturated hydrocarbon chain or a polyether chain as the main chain are preferred, and polymers having a saturated hydrocarbon chain as the main chain are more preferred. Further, it is preferred for the binder polymers to have a crosslinking structure.

As the binder polymers having a saturated hydrocarbon chain as the main chain, polymers of ethylenic unsaturated monomers are preferred. As the binder polymers having a saturated hydrocarbon chain as the main chain and a crosslinking structure, (co)polymers of monomers having two or more ethylenic unsaturated groups are preferred.

For making the hard coat layer a higher refractive index layer, it is preferred for the structure of the monomer to contain an aromatic ring, and at least one atom selected from a halogen atom other than a fluorine atom, a sulfur atom, a phosphorus atom and a nitrogen atom.

The examples of the monomers having two or more ethylenic unsaturated groups include esters of polyhydric alcohol and (meth)acrylic acid (e.g., ethylene glycol di(meth)acrylate, 1,4-cyclohexane diacrylate, pentaerythritol tetra(meth)- acrylate, pentaerythritol tri(meth)acrylate, trimethylol- propane tri(meth)acrylate, trimethylolethane tri(meth)- acrylate, dipentaerythritol tetra(meth)acrylate, dipenta- erythritol penta(meth)acrylate, dipentaerythritol hexa- (meth)acrylate, pentaerythritol hexa(meth)acrylate, 1,2,3- cyclohexane tetra(meth)acrylate, polyurethane polyacrylate, and polyester polyacrylate), vinylbenzene and derivatives thereof (e.g., 1,4-divinylbenzene, 4-vinylbenzoic acid-2- acryloylethyl ester, and 1,4-divinylcyclohexanone), vinyl sulfone (e.g , divinyl sulfone), acrylamide (e.g., methylene- bisacrylamide), and methacrylamide. These monomers may be used in combination of two or more kinds.

As the specific examples of high refractive index monomers, bis(4-methacryloylthiophenyl) sulfide, vinyl- naphthalene, vinylphenyl sulfide, and 4-methacryloxyphenyl- 4-methoxyphenyl thioether are exemplified These monomers may also be used in combination of two or more kinds.

Polymerization of these monomers having ethylenic unsaturated groups can be performed by irradiation with ionizing radiation or by heating in the presence of a photo-radical polymerization initiator or a thermal radical polymerization initiator.

As the photo-radical polymerization initiators, those described in the low refractive index layer can be used as they are.

As the thermal radical polymerization initiators, organic or inorganic peroxides, organic azo and diazo compounds can be used.

Specifically, as the organic peroxides, benzoyl peroxide, halogen benzoyl peroxide, lauroyl peroxide, acetyl peroxide, dibutyl peroxide, cumene hydroperoxide, and butyl hydro- peroxide, as the inorganic peroxides, hydrogen peroxide, ammonium peroxide, and potassium peroxide, as the azo compounds, 2,2'-azobis(isobutyronitrile), 2,2'-azobis(propionitrile), and l,r-azobis(cyclohexanecarbonitrile), and as the diazo compounds, diazoaminobenzene and p-nitrobenzenediazonium are exemplified.

As the polymers having polyether as the main chain, ring opening polymers of polyfunctional epoxy compounds are preferred. The ring opening polymerization of polyfunctional epoxy compounds can be performed by irradiation with ionizing radiation or heating in the presence of a photo-acid generator or a heat-acid generator.

Accordingly, the hard coat layer can be formed by preparing a coating solution containing a polyfunctional epoxy compound, a photo-acid generator or a heat-acid generator, matting particles, and inorganic fine particles, coating the coating solution on a transparent support, and curing the coating solution by polymerization reaction by irradiation with ionizing radiation or by heating

In place of, or in addition to, monomers having two or more ethylenic unsaturated groups, a crosslinking functional group may be introduced into the polymer by using a monomer having a crosslinking functional group to thereby cause reaction of the crosslinking functional group and introduce the crosslinking structure into the binder polymer.

The examples of the crosslinking functional groups include an isocyanate group, an epoxy group, an aziridine group, an oxazoline group, an aldehyde group, a carbonyl group, a hydrazine group, a carboxyl group, a methylol group, and an active

methylene group. A vinylsulfonic acid, an acid anhydride, a cyanoacrylate derivative, melamine, etherified methylol, ester, urethane, and metal alkoxide, e.g., tetramethoxysilane can also be used as the monomers for the introduction of a crosslinking structure. Functional groups showing a crosslinking property as a result of decomposition reaction, such as a blocked isocyanate group may also be used. That is, in the invention, crosslinking functional groups may be those that show reactivity as a result of decomposition, even if they do not show reactivity at once.

By coating these binder polymers having crosslinking functional groups and then heating, a crosslinking structure can be formed.

It is preferred that the hard coat layer in the invention contains inorganic fine particles for the purpose of adjusting refractive index, preventing shrinkage by crosslinking, and enhancing strength.

For heightening the refractive index of the hard coat layer, it is preferred for the hard coat layer to contain inorganic fine particles comprising at least a kind of oxide of the metal selected from among titanium, zirconium, aluminum, indium, zinc, tin and antimony, and having an average particle size of 0.2 μm or less, preferably 0.1 μm or less, and more preferably 0.06 μm or less

For lowering the refractive index on the other hand, a silicon oxide can be used. The preferred particle size is the same as the above inorganic fine particles.

The specific examples of inorganic fine particles for use in the hard coat layer include TiO ₂ , ZrO ₂ , Al ₂ O ₃ , In ₂ O ₃ , ZnO, SnO ₂ , Sb ₂ O ₃ , ITO and SiO ₂ TiO ₂ and ZrO ₂ are especially preferred for increasing a refractive index. It is also preferred for the surfaces of inorganic fine particles to be subjected to treatment with a silane coupling agent or a titanium coupling agent, and surface treating agents having functional groups capable of reacting with the binder are preferably used on the surfaces of fine

particles.

The addition amount of these inorganic fine particles is preferably from 10 to 90% of the entire mass of the hard coat layer, more preferably from 20 to 80%, and especially preferably from 30 to 75%.

Incidentally, the particle sizes of these inorganic fine particles are sufficiently smaller than the wavelength of light, so that light scattering does not occur and a dispersion comprising a binder polymer having dispersed therein these inorganic fine particles behaves as an optically uniform material.

The refractive index of total of the mixture of the binder and the inorganic fine particles in the hard coat layer in the invention is preferably from 1.48 to 2.00, and more preferably from 1.50 to 1.80. The above range of the refractive index can be reached by arbitrarily selecting the kinds and the ratio of the amounts of the binder and the inorganic fine particles. How to select can be easily known experimentally in advance.

For securing surface uniformity by improving coating unevenness, drying unevenness, point defect, etc., it is preferred to contain either a fluorine surfactant or a silicone surfactant, or both of them, in the coating composition for forming the hard coat layer. In particular, a fluorine surfactant has the effect of improving surface failure of the antireflection film of the invention, such as coating unevenness, drying unevenness, point defect, etc., with a smaller addition amount, so that preferably used.

The invention aims at increasing productivity by the impartation of high speed coating aptitude while increasing surface uniformity

However, by the use of a fluorine polymer as above, functional groups containing an F atom are segregated on the surface of the hard coat layer to reduce the surface energy of the hard coat layer, so that a problem of the deterioration of

antireflection performance occurs when a low refractive index layer is overcoated on the hard coat layer. This is presumably due to the fact that the wetting property of the coating composition used for forming the low refractive index layer is deteriorated, so that micro unevenness of the low refractive index layer that cannot be detected by visual observation is generated. For solving these problems, it has been found effective to control the surface energy of the hard coat layer by adjusting the structure and the addition amount of the fluorine polymer preferably to 20 to 50 mN/m, and more preferably to 30 to 40 mN/m. Further, for realizing surface energy as above, the ratio F/C of the peak originating in a fluorine atom and the peak originating in a carbon atom measured in accordance with X-ray photoelectron spectrometry is necessary to be from 0.1 to 1.5.

If the reduction of surface energy can be restrained at a point of time of overcoating the low refractive index layer on the hard coat layer, the deterioration of antireflection performance can be prevented. The object can also be achieved by reducing the surface tension of the coating solution by using a fluorine polymer to heighten the surface uniformity at the coating time of the hard coat layer and maintain high productivity by high speed coating, and after coating the hard coat layer, preventing the reduction of surface free energy by surface treatment such as corona treatment, UV treatment, heat treatment, saponification treatment, or solvent treatment, especially preferably with corona treatment, to control the surface free energy of the hard coat layer before coating the low refractive index layer to the above range.

For the purpose of imparting an antiglare property or inside scattering property, the hard coat layer may contain matting particles greater than the inorganic fine particles and having an average particle size of from 1.0 to 10 0 μm, and preferably from 1.5 to 7 0 μm, e.g., particles of an inorganic compound or resin

particles.

As the specific examples of the matting particles, such as the particles of inorganic compounds, e.g., silica particles TiO ₂ particles, etc., and resin particles, e.g., acrylic particles, crosslinked acrylic particles, polystyrene particles, crosslinked styrene particles, melamine resin particles, benzoguanamine resin particles, etc., are preferably exemplified. Of these particles, crosslinked styrene particles, crosslinked acrylic particles, and silica particles are preferred.

The shape of the matting particles may be either spherical or amorphous.

Two or more kinds of matting particles respectively having different particle sizes may be used in combination. It is possible to give an antiglare property to the hard coat layer with the greater matting particles and impart other optical characteristics with the smaller matting particles. For example, when an antiglare and antireflection film is stuck on a high precision display of 150 ppi or more, there are cases where a disadvantage, called "glare", from the viewpoint of the quality of a displayed image occurs. "Glare" results from the loss of uniformity of brightness by extension or shrinkage of pixels due to unevenness present on the surface of the antiglare and antireflection film. "Glare" can be largely improved by using in combination of matting particles having a smaller particle size than that of the matting particles to impart an antiglare property and a refractive index different from the refractive index of the binder

The particle size distribution of the matting particles is most preferably monodispersion, and the particle size of each particle is preferably as near as possible. For example, when the particles having particle sizes greater than the average particle size by 20% or more are defined as coarse particles, the rate of the coarse particles is preferably 1% or less of the total number of particles, more preferably 0 1% or less,

and still more preferably 0.01% or less. The matting particles having such particle size distribution can be obtained by classification after ordinary synthesis reaction, and matting particles having further preferred particle size distribution can be obtained by increasing the number of times of classification or by enhancing the degree of classification.

The matting particles are contained in the antiglare hard coat layer so that the amount of the matting particles in the antiglare hard coat layer to be formed is preferably from 10 to 1,000 mg/m ² , and more preferably from 100 to 700 mg/m ² .

The particle size distribution of matting particles is measured with a Coulter counter, and the measured particle size distribution is converted to particle number distribution.

The thickness of the hard coat layer is preferably from 1.0 to 10.0 μm, and more preferably from 1.2 to 7.0 μm.

The haze of the hard coat layer is preferably from 0 to 70%, more preferably from 0 to 60%, and most preferably from 0 to 50%.

The strength of the hard coat layer is preferably H or higher by the pencil test in accordance with JIS-K-5600-5-4, more preferably 2H or higher, and most preferably 3H or higher.

When the hard coat layer is formed by crosslinking reaction or polymerization reaction of an ionizing radiation- curable compound, it is preferred that the crosslinking reaction or polymerization reaction is carried out in the atmosphere of oxygen concentration of 10% or less. By forming in the atmosphere of oxygen concentration of 10% or less, a hard coat layer excellent in physical strength and chemical resistance can be formed even when the curing conditions (e.g., the dose of ionizing radiation) are set at moderate conditions.

It is preferred to form the hard coat layer by crossl inking reaction or polymerization reaction of an ionizing radiation-curable compound in the atmosphere of oxygen concentration of 6% or less, more preferably in the atmosphere of oxygen concentration of 2% or less, especially preferably in the atmosphere of oxygen concentration of 1% or less, and most preferably 0.1% or less.

As a means for bringing oxygen concentration to 10% or less, it is preferred to substitute the atmospheric air with another gas as described above, and the substitution with nitrogen is especially preferred.

Irradiation of ionizing radiation is preferably performed with a high pressure mercury lamp and a metal halide lamp. The energy of irradiation should be sufficient that the dose does not cause the discoloration of the dye contained in the hard coat layer and curing reaction satisfactorily advances. Specifically, the dose of the range of from 50 to 1,000 mJ/cm ² is preferred, from 50 to 700 ml/cm ² is more preferred, and the range of from 100 to 500 mJ/cm ² is especially preferred.

For expediting curing, it is also preferred to perform heating at the same time with the irradiation with ionizing radiation, or after irradiation When heating is performed, the temperature of the least upper bound is determined from the point of the heat resistance of the dyes contained in the transparent support and the hard coat layer The heating temperature is preferably in the range of from 30 to 12O ⁰ C or so, more preferably from 70 to 110 ⁰ C, and especially preferably from 80 to 100 ⁰ C

Heating methods are not especially limited, but a method of heating a roll and bringing into contact with a web, a method of blasting heated nitrogen, and a method of irradiation with far infrared rays or infrared rays are preferred A method of heating by applying a medium such as hot water, steam or oil to a rotating metal roll as disclosed in Japanese Patent 2523574 can also be utilized.

The hard coat layer is preferably formed by coating a coating composition for forming the hard coat layer on the surface of a transparent support.

As solvents of the coating solutions used for forming the hard coat layer and the low refractive index layer in the invention, it is preferred to use a ketone solvent, either alone or as a mixture. When ketone solvent is used as a mixed solvent, the content of the ketone solvent is preferably 10 mass% or more of all the solvents contained in the coating composition, more preferably 30 mass% or more, and still more preferably 60 mass% or more.

Solvents other than ketone solvents may be contained in the coating solvent. For example, as the solvents having a boiling point of 100 ⁰ C or lower, hydrocarbons, e.g., hexane (boiling point: 68.7 ⁰ C, hereinafter ⁰ C is omitted), heptane (98.4), cyclohexane (80.7), and benzene (80.1); halogenated hydrocarbons, e.g., dichloromethane (39.8), chloroform (61.2), carbon tetrachloride (76.8), 1,2-dichloroethane (83.5), and trichloroethylene (87.2); ethers, e.g., diethyl ether (34.6), diisopropyl ether (68.5), dipropyl ether (90.5), and tetrahydrofuran (66); esters, e.g., ethyl formate (54.2), methyl acetate (57.8), ethyl acetate (77.1), and isopropyl acetate (89); ketones, e.g., acetone (56.1), and 2-butanone (equivalent to methyl ethyl ketone, 79.6); alcohols, e.g., methanol (64.5), ethanol (78.3), 2-propanol (82.4), and 1-propanol (97.2); cyano compounds, e.g., acetonitrile (81.6), and propionitrile (97.4); and carbon disulfide (46.2) are known. Of these solvents, ketones and esters are preferred, and ketones are especially preferred. Of ketones, 2-butanone is especially preferred.

As the solvents having a boiling point of 100 ⁰ C or higher, octane (125.7), toluene (110.6), xylene (138), tetrachloro- ethylene (121.2), chlorobenzene (131.7), dioxane (101.3), dibutyl ether (142.4), isobutyl acetate (118), cyclohexanone (155.7),

2-methyl-4-pentanone (equivalent to methyl isobutyl ketone (MIBK), 115.9), 1-butanol (117.7), N,N-dimethyl- formamide (153), N,N-dimethylacetamide (166), and dimethyl sulfoxide (189) are known, and the preferred are cyclohexanone and 2-methyl-4-pentanone.

By diluting the components of the hard coat layer and the low refractive index layer with these solvents each having the above composition, the coating solutions of these layers are prepared. The concentration of the coating solutions is preferably arbitrarily adjusted considering the viscosity of the coating solutions, and the specific viscosity of each layer, but is generally from 0.01 to 60 mass% or so, preferably from 0.05 to 50 mass%, especially preferably from 0.1 to 20 mass%, and most preferably from 1 to 10 mass%. (Dye)

The antireflection film in the invention is characterized in that the hard coat layer contains a dye to have a color correcting function.

The color correcting functional layer has the absorption maximum in the wavelength region of from 560 to 620 nm (between green and red). The absorption maximum in the wavelength region of from 560 to 620 nm has a function of selectively cutting the sub-band that reduces the color purity of a red fluorescent substance. In a plasma display panel, unnecessary luminescence in the vicinity of 595 nm that is emitted by the excitation of neon gas can also be cut. For further lowering the influence on the tone of a green fluorescent substance, the absorption maximum in the wavelength region of from 560 to 620 nm is preferably sharp. Specifically, in the wavelength region of from 560 to 620 nm, the half width (the width of the wavelength region showing half the absorbance of the absorbance of the absorption maximum) is preferably from 10 to 200 nm, more preferably from 15 to

120 nm, still more preferably from 20 to 100 nra, and most preferably from 22 to 80 nm. The transmittance of the color correcting functional layer at the absorption maximum in the wavelength region of from 560 to 620 nm is preferably in the range of from 0.01 to 80%, more preferably from 0.1 to 60%, and most preferably from 0.2 to 50%.

As dyes having the absorption maximum in the wavelength region of from 560 to 620 nm, it is preferred to use methine dyes, anthraquinone dyes, triphenylmethane dyes, xanthene dyes, azo dyes, or azomethine dyes. It is more preferred to use methine dyes. Methine dyes can be classified into cyanine dyes, oxonol dyes, merocyanine dyes, arylidene dyes and styryl dyes. Cyanine dyes are especially preferably used. The examples of preferred cyanine dyes are disclosed, e.g., in JP-A-2001-74930 in detail.

The specific examples of preferred cyanine dyes are shown below.

(I) RaI -CH ₃₅ RbI -C ₄ H ₈ SO ₃ ^"

(2) Ra: -CH ₃ , Rb: -C ₃ H ₆ SO ₃ ^"

(3) Ra: -C ₂ H ₅ , Rb: -C ₃ H ₆ SO ₃ ^"

(4) Ra: -C ₂ H ₅ , Rb: -C ₄ H ₈ SO ₃ ^"

(5) Ra: -C ₄ H ₈ SO ₃ ^" , Rb -C ₂ H ₅

(6) Ra: -C ₃ H ₆ SO ₃ ^" , Rb: -CH ₃

(7) Ra: -C ₂ H ₄ SO ₃ ^' , Rb: -C ₂ H ₅

Methine dyes can be synthesized with referring to RM. Harmer, Heterocyclic Compounds-Cyanine Dyes and Related Compounds, John Wiley and Sons, New York, London (1964), D.M. Sturmer, Heterocyclic Compounds-Special Topics in Heterocyclic Chemistry, Chapter 18, Clause 14, pages 482-515, John Wiley and Sons, New York, London (1977); Rodd's Chemistry of Carbon Compounds, 2 ^nd Edition, Volume 4, Part B, Chapter 15, pages 369-422, Elsevier Science Publishing Company Inc., New York (1977); JP-A-5-88293 and JP-A-6-313939.

In addition to the wavelength region of from 560 to 620 nm (between green and red), the color correcting functional layer may have the absorption maximum in the wavelength region of from 500 to 550 nm (green). The half width of the absorption maximum in the wavelength region of from 500 to 550 nm is preferably broader than the half width of the absorption maximum in the wavelength region of from 560 to 620 nm. Further, it is preferred that the transmittance of the color correcting functional layer at the absorption maximum in the wavelength region of from 500 to 550 nm is greater than the transmittance of the color correcting functional layer at the absorption maximum in the wavelength region of from 560 to 620 nm The absorption maximum in the wavelength region of from 500 to 550 nm has a

function to adjust the emission intensity of a green fluorescent substance of high visibility. It is preferred to cut the emission region of a green fluorescent substance gently. Specifically, in the wavelength region of from 500 to 550 nm, the half width (the width of the wavelength region showing half the absorbance of the absorbance of the absorption maximum) is preferably from 30 to 300 nm, more preferably from 40 to 250 nm, still more preferably from 50 to 200 nm, and most preferably from 60 to 150 nm. The transmittance of the color correcting functional layer at the absorption maximum in the wavelength region of from 500 to 550 nm is preferably in the range of from 5 to 90%, more preferably from 20 to 85%, and most preferably from 50 to 80%. As dyes having the absorption maximum in the wavelength region of from 500 to 550 nm, oxonol dyes, azo dyes, azomethine dyes, anthraquinone dyes, cyanine dyes, merocyanine dyes, benzylidene dyes, and xanthene dyes can be used.

These dyes may be used in combination with dyes having the absorption maximum in the wavelength regions different from the above wavelength regions (from 500 to 550 nm, and from 560 to 620 nm). As such dyes, near infrared absorbing dyes can be used. As the near infrared absorbing dyes, cyanine dyes (the dyes disclosed in JP-A-9-96891), metal chelate dyes, aluminum dyes, diimonium dyes, quinone dyes, squarylium dyes (the dyes disclosed in JP-A-9-90547 and JP-A- 10-204310), and various methine dyes can be used. Near infrared absorbing dyes are also described in Shikizai (Coloring Materials), 61 [4] 215-226 (1988), and Kagaku Kogyo (Chemical Industry), 43-53 (May, 1986). As other visible ray absorbing dyes, triphenyl- methane dyes (U.S. Patent 2,150,695 and JP-A-5-117536), and fluorescein dyes (e.g., fluorescein, dibromofluorescein, Eosine, Rhodamine) can be used (Discoloration Inhibitor)

The hard coat layer of the antireflection film in the invention contains a dye to have a color correcting function, and a discoloration inhibitor is used in combination to maintain and improve durability of the dye.

As the discoloration inhibitors, a phenolic compound, a phenol ether compound, an aniline compound, a quinone compound or a piperidine compound is used. In the specification of the invention, the phenolic compound means a compound having a phenolic hydroxyl group. The phenol ether compound means ether obtained by substituting the hydrogen atom of the phenolic hydroxyl group of a phenolic compound with an aliphatic group or an aromatic group. The aniline compound means a compound having an amino-substituted benzene ring. The quinone compound means a compound having a quinone ring (preferably a p-quinone ring). The piperidine compound means a compound having a piperidine ring. The examples of the preferred phenolic compounds, phenol ether compounds, aniline compounds, quinone compounds, and piperidine compounds are disclosed in detail in, e.g., JP-A-2001-74930.

The specific examples of preferred phenolic compound, phenol ether compounds, aniline compounds, quinone compounds and piperidine compounds are shown below.

Phenolic compound, phenol ether compounds, aniline compounds, quinone compounds and piperidine compounds can be synthesized by performing easy reaction such as alkylation treatment of phenol, aniline, quinone or piperidine. Many of these compounds are on the market and commercially available products can be used. Two or more discoloration inhibitors may be used in combination. It is preferred for the color correcting functional layer to contain a discoloration inhibitor in the range of the amount of from 0.1 to 1000 mass%, more preferably the amount of from 5 to 500 mass%, and most preferably from 10 to 200 mass%.

The hard coat layer may contain other discoloration inhibitors and UV absorbers. As the examples of discoloration inhibitors that function as a stabilizing agent of dyes, hydroquinone derivatives (e.g., those disclosed in U.S. Patents 3,935,016 and 3,982,944), hydroquinone diether derivatives (e.g., U.S. Patent 4,254,216 and JP-A-55-21004), phenolic derivatives (e g., JP-A-54-145530), derivatives of spiroindane and methylenedioxybenzene (e.g., British Patents 2,077,455, 2,062,888 and JP-A-61-90155), derivatives of chroman, spirochroman and coumaran (e.g., U.S. Patents 3,432,300, 3,573,050, 3,574,627, 3,764,337, JP-A-52-152225, JP-A-53-20327, JP-A-53-17729 and JP-A-61-90156), derivatives of hydroquinone

monoether and para-aminophenol (e.g., British Patent 1,347,556, 2,066,975, JP-B- 54- 12337 (the term "JP-B" as used herein refers to an "examined Japanese patent publication"), and JP-A-55-6321), and bisphenol derivatives (e.g., U.S. Patent 3,700,455 and JP-B-48-31625) are included.

For the purpose of improving the stability to light or heat, metal complexes (e.g., U.S. Patent 4,245,018 and JP-A-60- 97353) may be used as a discoloration inhibitor. Further, to improve a light fastness property of dyes, singlet oxygen quenchers may be used as a discoloration inhibitor. The examples of singlet oxygen quenchers include nitroso compounds (e.g., JP-A-2-300288), diimonium (e.g., U.S. Patent 465,612), nickel complexes (e.g., JP-A-4-146189), and antioxidants (e.g., EP 820057). (Transparent Support)

The examples of the materials for forming a transparent support include cellulose esters (e.g., diacetyl cellulose, triacetyl cellulose (TAC), propionyl cellulose, butyryl cellulose, acetylpropionyl cellulose, nitro cellulose), polyamide, polycarbonate, polyesters (e.g., polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, poly-l,4-cyclohexanedimethylene terephthalate, polyethylene- l,2-diphenoxyethane-4,4'- dicarboxylate, polybutylene terephthalate), polystyrenes (e.g. syndiotactic polystyrene), polyolefins (e g , polyethylene, polypropylene, polymethylpentene), polymethyl methacrylate, syndiotactic polystyrene, polysulfone, polyether sulfone, polyether ketone, polyether imide, and polyoxyethylene Triacetyl cellulose, polycarbonate and polyethylene terephthalate are preferred. The transmittance of a transparent support is preferably 80% or more, and more preferably 86% or more. The haze of a transparent support is preferably 2% or less, and more preferably 1% or less The refractive index of a transparent

support is preferably from 1.45 to 1.70.

An infrared absorber or a UV absorber may be added to a transparent support. The addition amount of an infrared absorber or a UV absorber is preferably from 0.01 to 20 mass% of the transparent support, and more preferably from 0.05 to 10 mass%. Further, particles of an inert inorganic compound may be added to a transparent support as a lubricant. The examples of the inorganic compounds include SiO ₂ , TiO ₂ , BaSO ₄ , CaCO ₃ , talc and kaolin. A transparent support may be subjected to surface treatment. The examples of the surface treatments include chemical treatment, mechanical treatment, corona discharge treatment, flame treatment, ultraviolet irradiation treatment, high frequency treatment, glow discharge treatment, active plasma treatment, laser treatment, mixed acid treatment, and ozone oxidation treatment. Of these treatments, glow discharge treatment, ultraviolet irradiation treatment, corona discharge treatment, and flame treatment are preferred, and glow discharge treatment and ultraviolet irradiation treatment are more preferred. Further, an undercoat layer may be provided for the purpose of enhancement of adhesion with the upper layer. (Undercoat Layer)

The undercoat layer in the invention is formed as a layer containing a polymer having a glass transition temperature of from -60 to +60 ⁰ C, a layer having a roughened surface on the side of a hard coat layer, or a layer containing a polymer having affinity for the polymer in a hard coat layer. The undercoat layer may be provided to improve the affinity of the adhesive, which is used to adhere an antireflection film to an image display device, for the antireflection film. The thickness of the undercoat layer is preferably from 2 nm to 20 μm, more preferably from 5 nm to 5 μm, and most preferably from 50 nm to 5 μm

The undercoat layer containing a polymer having a glass transition

temperature of from -60 to +6O ⁰ C functions to adhere a transparent support and a hard coat layer by the stickiness of the polymer. Polymers having a glass transition temperature of 25°C or less can be obtained by polymerization or copolymerization of vinyl chloride, vinylidene chloride, vinyl acetate, butadiene, neoprene, styrene, chloroprene, acrylic ester, methacrylic ester, acrylonitrile or methyl vinyl ether. The glass transition temperature is preferably 2O ⁰ C or less, more preferably 15 ⁰ C or less, still more preferably 1O ⁰ C or less, yet more preferably 5°C or less, and most preferably O ⁰ C or less. The undercoat layer having a roughened surface adheres a transparent support and a hard coat layer by forming the hard coat layer on the roughened surface. The undercoat layer having a roughened surface can be easily formed by coating a polymer latex. The average particle size of the latex is preferably from 0.02 to 3 μm, and more preferably from 0.05 to 1 μm. The examples of the polymer having affinity for the binder polymer in a hard coat layer include acrylic resin, cellulose derivative, gelatin, casein, starch, polyvinyl alcohol, soluble nylon, and a polymer latex. Two or more undercoat layers may be provided. The undercoat layer may contain a solvent for swelling a transparent support, a matting agent, a surfactant, an antistatic agent, a coating assistant, and a hardening agent. (High Refractive Index Layer, Low Refractive Index Layer)

In the antireflection film in the invention, a high refractive index layer having a refractive index higher than the refractive index of the transparent support or the hard coat layer may be provided between the hard coat layer and the low refractive index layer. Further, a middle refractive index layer (a layer having a refractive index higher than that of the transparent support or the hard coat layer and lower than that of the high refractive index layer) may be provided between the hard coat layer and the high refractive index layer.

The refractive index of the high refractive index layer is preferably from 1.60 to 2.40, and more preferably from 1.70 to 2.20. The refractive index of the middle refractive index layer is adjusted so as to be the value between the refractive index of the low refractive index layer and the refractive index of the high refractive index layer. The refractive index of the middle refractive index layer is preferably from 1.55 to 1.80. The haze value of the high refractive index layer and the middle refractive index layer is preferably 3% or less.

Such high refractive index layer and middle refractive index layer can be formed by the adjustment of the use amounts of the high refractive index filler and high refractive index monomer for use in the hard coat layer.

The haze value of the thus-formed antireflection film of the invention is preferably from 0 to 70%, more preferably from 0 to 60%, and most preferably from 0 to 50%.

The strength of the antireflection film is preferably 2H or higher by the pencil test in accordance with JIS-K-5600-5-4, more preferably 3H or higher, and most preferably 4H or higher.

The average reflectance of regular reflection at 5° (wavelength region: 450 to 650 nm) of the antireflection film is preferably 2.0% or less, more preferably 1.5% or less, and most preferably 1.3% or less. (Other Layers)

The antireflection film in the invention can also be provided with an electromagnetic wave shielding layer, an infrared shielding layer, a lubricating layer, an antifouling layer, an antistatic layer, an ultraviolet absorbing layer and the like.

The surface electrical resistance of the layer having electromagnetic wave shielding effect is preferably from 0.1 to 500 ω/cm ² , and more preferably from 0.1 to

10 ω/cm ² . Since the electromagnetic wave shielding layer is a layer provided on an antireflection film, the layer is preferably transparent. Layers generally known as transparent conductive layers can be used as the electromagnetic wave shielding layer. As the transparent conductive layer, a metallic thin film and a metallic oxide thin film are preferably used.

The infrared shielding layer preferably has shielding effect against near infrared rays of wavelengths of from 800 to 1,200 nm. The infrared shielding layer can be formed from resin mixtures. The infrared shielding components in resin mixtures are disclosed, e g., in JP-A-62-5190, JP-A-6-118228, JP-A-6-73197, and U.S. Patent 3,647,772

By forming the lubricating layer on the outermost surface of an antireflection layer, the surface of the antireflection layer is given with a lubricating property to thereby have a function of improving scratch resistance. The lubricating layer can be formed with polyorganosiloxane (e.g., silicone oil), natural waxes, petroleum waxes, higher fatty acid metal salts, fluorine lubricants, and derivatives thereof. The thickness of the lubricating layer is preferably from 2 to 20 nm

The antifouling layer can be formed with a fluorine- containing polymer. The thickness of the antifouling layer is preferably from 2 to 100 nm, and more preferably from 5 to 30 nm (Film Forming Method)

The antireflection film in the invention can be formed by the following method, but the invention is not restricted thereto

In the first place, a coating solution containing the components for forming each layer is prepared A coating solution for forming a hard coat layer is then coated on a transparent support by dip coating, air knife coating, curtain coating, roller

coating, wire bar coating, gravure coating, or extrusion coating (refer to U.S. Patent 2,681,294), and the coated solution is heated and dried. Micro gravure coating and extrusion coating are preferred, and micro gravure coating is especially preferred. And then, the monomer for forming the hard coat layer is polymerized and cured by irradiation with light or heating, thus the hard coat layer is formed.

In the next place, a coating solution for forming a low refractive index layer is coated on the hard coat layer in the same manner as above, and the coated solution is subjected to irradiation with light or heating to form a low refractive index layer. Thus the antireflection film in the invention is obtained.

The micro gravure coating method used in the invention is a coating method of using a gravure roll having a diameter of about 10 to 100 mm, and preferably about 20 to 50 mm, and gravure pattern is engraved on the entire circumferential surface. The gravure roll is on the lower side of the support and inversely rotated against the traveling direction of the support, and an excess amount of the coating solution is scraped off with a doctor blade from the surface of the gravure roll and a determined amount of the coating solution is coated by transfer on the lower side of the support at the position where the upper side of the transparent support is in a free state. A transparent support in a rolled state is continuously unrolled, and at least one layer of a hard coat layer and a low refractive index layer containing a fluorine-containing polymer can be coated on one side of the unrolled support by micro gravure coating.

As the coating conditions by a micro gravure coating method, the number of lines of the gravure pattern engraved on a gravure roll is preferably from 50 to 800/inch, more preferably from 100 to 300/inch, the depth of the gravure pattern is preferably from 1 to 600 μm, more preferably from 5 to 200 μm, the rotation number of the gravure roll is preferably from 3 to 800 rpm, more preferably from 5 to 200 rpm,

and the transfer speed of a support is preferably from 0.5 to 100 m/min, and more preferably from 1 to 50 m/min.

Further, a layer having a uniform layer thickness can be formed with a small coating amount of a coating solution with a die coating method, and a die coating method is a pre-measuring system, so that the control of a layer thickness is relatively easy, and the transpiration of a solvent at a coating area is little and preferred. As a method of coating a thin layer coating solution of several ten micrometers or less of a wet film thickness on, e.g., a plastic film with a specific slot die or a coating method, the coating methods disclosed in JP- A-2003 -200097, JP-A-2003-211052, JP-A-2003- 230862, JP-A-2003-236434, JP-A-2003-236451, JP-A-2003-245595,

JP-A-2003-251260, JP-A-2003-260400, JP- A-2003 -260402, JP-A- 2003-275652, and JP-A-2004-141806 are also preferably used. Two or more layers may be coated at the same time. Simultaneous coating methods are described, e.g., in U.S. Patents 2,761,791, 2,941,898, 3,508,947, and 3,526,528, and Yuji Harasaki, Coating Kogaku (Coating Engineering), p. 253 (1973), Asakura Publishing Co. (Image Display Device)

The antireflection film in the invention is applied to image display devices such as a plasma display panel (PDP), a liquid crystal display (LCD), an electroluminescence display (ELD), and a cathode ray tube display (CRT). The surface of the side of the antireflection film on which a low refractive index layer is not provided is arranged so as to be opposed to the image display surface of an image display device. The antireflection film in the invention exhibits especially conspicuous effect when used as the antireflection film of PDP PDP consists of gas, glass substrates, electrodes, electrode lead material, a thick film printing material and a fluorescent substance. The glass substrate consists of two panels of a front glass

substrate and a rear glass substrate. An electrode and an insulating layer are formed on the two glass substrates. A phosphor layer is further formed on the rear glass substrate. Two glass substrates are assembled and gas is sealed between. PDP is described in JP-A-5-205643 and JP-A-9-306366.

EXAMPLE

The invention will be described with reference to examples, but the invention is not limited thereto. In the examples "parts" and "%" mean "mass parts" and "mass%" unless otherwise indicated. (EXAMPLE 1) (Preparation of Inorganic Fine Particle Dispersion (P-I))

A commercially available silica particle dispersion having an average particle size of 50 nm (IPA-ST-L, silica solid content concentration: 30 mass%, solvent: isopropyl alcohol, manufactured by Nissan Chemical Industries, Ltd.) was diluted with isopropyl alcohol in silica solid content concentration of 20 mass% to prepare inorganic fine particle dispersion (P-I). (Preparation of Inorganic Fine Particle Dispersion (P-2))

A mixed solution obtained by adding 900 g of ion exchange water and 800 g of ethanol to 100.0 g of the obtained inorganic fine particle dispersion (P-I) was heated at 3O ⁰ C, and 360 g of tetraethoxysilane (SiO ₂ concentration: 28 mass%) and 626 g of 28% aqueous ammonia were added to the mixed solution to form a silica shell layer on the surface of the particles with a hydrolyzed polycondensed product of tetraethoxysilane. After the reaction product was concentrated to solid content concentration of 5 mass% with an evaporator, aqueous ammonia of concentration of 15 mass% was added thereto to make the pH 10, and the reaction mixture was subjected

to heat treatment in an autoclave at 18O ⁰ C for 4 hours, followed by substitution of the solvent with ethanol with an ultrafiltration membrane, thus inorganic fine particle dispersion (P-2) having solid content concentration of 20 mass% was prepared. (Preparation of Inorganic Fine Particle Dispersion (P-3))

Tetraethoxysilane (TEOS, SiO ₂ concentration: 28 mass%) (360 g) and 530 g of methanol were mixed. Into the mixed solution at 25°C were dropped 100 g of ion exchange water and 1O g of 28% aqueous ammonia, and the solution was ripened with stirring for 24 hours, and then the reaction solution was subjected to heat treatment in an autoclave at 18O ⁰ C for 4 hours, followed by substitution of the solvent with ethanol with an ultrafiltration membrane, thus inorganic fine particle dispersion (P-3) having solid content concentration of 20 mass% was prepared. The particles were confirmed to be porous particles by observation with a scanning electron microscope. (Preparation of Inorganic Fine Particle Dispersion (P-4))

After a mixed solution obtained by adding 900 g of ion exchange water and 800 g of ethanol to 100.0 g of the prepared inorganic fine particle dispersion (P-3) was heated at 3O ⁰ C, 360 g of tetraethoxysilane (SiO ₂ concentration: 28 mass%) and 626 g of 28% aqueous ammonia were added to the mixed solution to form a silica shell layer on the surface of the particles with a hydrolyzed polycondensed product of tetraethoxysilane. After the reaction product was concentrated to solid content concentration of 5 mass% with an evaporator, aqueous ammonia of concentration of 15 mass% was added thereto to make the pH 10, and the reaction mixture was subjected to heat treatment in an autoclave at 18O ⁰ C for 4 hours, followed by substitution of the solvent with ethanol with an ultrafiltration membrane, thus inorganic fine particle dispersion (P-4) having solid content concentration of 20 mass% was prepared. (Preparation of Inorganic Fine Particle Dispersion (P-5))

A reaction mother solution was prepared by mixing 90 g of silica sol having an average particle size of 5 nm and SiO ₂ concentration of 20 mass% and 1,710 g of ion exchange water and heated at 95 ⁰ C. The pH of the reaction mother solution was 10.5. To the mother solution were simultaneously added 24,900 g of a 1.5 mass% sodium silicate aqueous solution as SiO ₂ , and 36,800 g of a 0.5 mass% sodium aluminate aqueous solution as Al ₂ θ3. The temperature of the reaction solution was maintained at 91 ⁰ C meanwhile. After termination of addition, the reaction solution was cooled to room temperature, and washed with an ultrafiltration membrane to prepare dispersion (A) containing SiO ₂ " Al ₂ O ₃ core particles having solid content concentration of 20 mass% (first preparation process).

In the next place, 500 g of dispersion (A) containing core particles was taken out, 1,700 g of ion exchange water was added thereto and heated at 98°C and, while maintaining this temperature, 2,100 g of a silicic acid solution (SiO ₂ concentration: 3.5 mass%) obtained by dealkalization of a sodium silicate aqueous solution with a cation exchange resin was added to the above mixed solution to form a silica protective film on the surface of the core particles. After the core particle dispersion containing core particles having the obtained silica protective film was washed with an ultrafiltration membrane to adjust the concentration of solid content to 13 mass%, 1,125 g of ion exchange water was added to 500 g of the core particle dispersion, and further a concentrated hydrochloric acid (35.5%) was dropped to the dispersion to adjust the pH to 1.0, and dealuminizing treatment was performed. While adding 10 liters of a hydrochloric acid aqueous solution having pH of 3 and 5 liters of ion exchange water, dissolved aluminum salt was separated with an ultrafiltration membrane to thereby prepare a dispersion of particle precursor (second preparation process).

After a mixed solution of 1,500 g the dispersion of particle precursor, 500 g of

ion exchange water, and 1,750 g of ethanol was heated at 3O ⁰ C, 70 g of tetraethoxysilane (SiO ₂ concentration: 28 mass%) and 626 g of 28% aqueous ammonia were added to the mixed solution with controlling the addition speed to form a silica shell layer on the surface of the particle precursor with a hydrolyzed polycondensed product of tetraethoxysilane, whereby particles having a cavity inside the shell layer. After the reaction product was concentrated to solid content concentration of 5 mass% with an evaporator, aqueous ammonia of concentration of 15 mass% was added thereto to make the pH 10, and the reaction mixture was subjected to heat treatment in an autoclave at 180 ⁰ C for 4 hours, followed by substitution of the solvent with ethanol with an ultrafiltration membrane, thus dispersion (P-5) of hollow silica fine particle sol (pore-containing inorganic fine particles) having solid content concentration of 20 mass% was prepared (third preparation process). (Evaluation of Inorganic Fine Particles)

The thus-obtained particles were evaluated as follows. (Evaluation 1 : Measurement of particle size)

Each dispersion was diluted and scooped up on grid and observed with a scanning electron microscope. The average particle size of 1,000 particles was found. (Evaluation 2: Computation of refractive index of particle)

A film was formed according to the above-described method by changing the content in the matrix The refractive index of the film was measured, and the refractive index at the time of the film comprising inorganic fine particles 100% was extrapolated and the refractive index of the film was computed.

The results of evaluations 1 and 2 are shown in Table 2 below together with the results obtained when incorporated into each antireflection film.

A multilayer antireflection film shown below was manufactured. (Synthesis of Perfluoroolefin Copolymer (I))

An autoclave having a capacity of 100 ml and equipped with a stainless steel stirrer was charged with 40 ml of ethyl acetate, 14.7 g of hydroxyethyl vinyl ether, and 0.55 g of dilauroyl peroxide, and then deaerated and substituted with nitrogen gas. Further, 25 g of hexafluoropropylene (HFP) was introduced to the autoclave and temperature was raised to 65 ⁰ C The pressure in the autoclave at the point of time when temperature reached 65 ⁰ C was 0.53 MPa (5.4 kgf/cm ² ). The reaction was continued for 8 hours while maintaining the temperature at 65°C, and heating was ceased when the pressure reached 0.31 MPa (3.2 kgf/cm ² ) and the reaction system was allowed to cool down. At the point of time when the temperature lowered to room temperature, unreacted monomer was got out, the autoclave was opened and the reaction solution was expelled The obtained reaction solution was put into greatly excessive hexane, and the precipitated polymer was taken out by removing the solvent by decantation. The monomer was dissolved in a small amount of ethyl acetate and reprecipitated two times from hexane to thereby completely remove the remaining monomer After drying, 28 g of a polymer was obtained. In the next place, 20 g of the polymer was dissolved in 100 ml of N,N-dimethyl- acetamide, and after 1 1 4 g of acrylic acid chloride was dropped to the polymer while ice-cooling, stirring was continued for 10 hours at room temperature. Ethyl acetate was added to the reaction

solution and washed with water, and the reaction solution was concentrated after extracting an organic layer. By reprecipitating the obtained polymer with hexane, 19 g of perfluoroolefin copolymer (1) was obtained. The refractive index of the obtained polymer was 1.421. (Preparation of Sol Component a)

After 120 parts of methyl ethyl ketone, 100 parts of acryloyloxypropyltrimethoxysilane (KBM-5103, manufactured by Shin-Etsu Chemical Co., Ltd.), and 3 parts of diisopropoxy- aluminum ethylacetoacetate (Chelope EP-12, trade mane, manufactured by Hope Chemical Co., Ltd.) were put into a reaction vessel equipped with a stirrer and a reflux condenser and mixed, 30 parts of ion exchange water was added thereto, the mixed solution was allowed to react at 6O ⁰ C for 4 hours, and then cooled to room temperature, thus sol solution a was obtained. The mass average molecular weight of the sol solution a was 1,600, and of the components higher than oligomer component, the components having molecular weight of from 1,000 to 20,000 accounted for 100%. From gas chromatographic analysis, acryloyloxypropyltrimethoxysilane of the starting material was not present at all The concentration of solid content was adjusted to 29% with methyl ethyl ketone to make sol component a. (Preparation of Dispersion (D-5))

While adding isopropyl alcohol to 500 parts of the above manufactured dispersion (P-5) of hollow silica fine particle sol (silica concentration: 20 mass%, an ethanol dispersion) so that the content of silica was almost constant, the solvent was substituted by vacuum distillation at pressure of 20 kPa To 500 parts of the thus-obtained silica dispersion (silica concentration. 20%), 30 parts of acryloyloxypropyltrimethoxy- silane (KBM-5103, manufactured by Shin-Etsu

Chemical Co., Ltd.), and 1 5 parts of diisopropoxyaluminum ethylaceto- acetate (Chelope EP-12, trade mane, manufactured by Hope Chemical Co., Ltd.) were added and mixed, and then 9 parts of ion exchange water was added thereto. After the reaction system was allowed to react at 60 ⁰ C for 8 hours, cooled to room temperature, and 1.8 parts of acetylacetone was added. While adding cyclohexanone to 500 g of the dispersion so that the content of silica was almost constant, the solvent was substituted by vacuum distillation at pressure of 20 kPa. The dispersion was not accompanied by generation of foreign matters, and the coefficient of viscosity at the time when the concentration of solids content was adjusted to 20 mass% with cyclohexanone was 5 mPa s at 25 ⁰ C. The residual amount of isopropyl alcohol of the obtained dispersion (D-5) analyzed by gas chromatography was 1.5%.

The above-prepared other inorganic fine particle dispersions (P-I) to (P-4) were subjected to treatment in accordance with the preparation of dispersion (D-5) to prepare corresponding dispersions (D-I) to (D-4) (Preparation of Low Refractive Index Layer Coating Solution (L-I))

To 100 mass parts of methyl ethyl ketone, 71.0 mass parts of perfluoroolefin copolymer (1), 7.0 mass parts of terminal methacrylate group-containing silicone RMS-033 (manufactured by Gelest), and 7 0 mass parts of photo-radical generator Irgacure 907 (manufactured by Ciba Specialty Chemicals Inc.) were added and dissolved. After that, 51 7 mass parts of sol component a (15.0 mass parts as solids content) was added to the above solution The solution was diluted with cyclohexanone and methyl ethyl ketone so that the concentration of solids content of the coating solution at large was 6 mass% and the ratio of cyclohexanone/methyl ethyl ketone was 10/90, thus coating solution (L-I) was prepared. (Preparation of Low Refractive Index Layer Coating Solution (L-6))

To 100 mass parts of methyl ethyl ketone, 42.0 mass parts of perfluoroolefin copolymer (1), 4.0 mass parts of terminal methacrylate group-containing silicone RMS-033 (manufactured by Gelest), and 4.0 mass parts of photo-radical generator Irgacure 907 (manufactured by Ciba Specialty Chemicals Inc.) were added and dissolved. After that, 175 mass parts of dispersion (D-5) (35.0 mass parts as solids content of silica plus surface treating agent), and 51.7 mass parts of sol component a (15.0 mass parts as solids content) were added to the above solution. The solution was diluted with cyclohexanone and methyl ethyl ketone so that the concentration of solids content of the coating solution at large was 6 mass% and the ratio of cyclohexanone/methyl ethyl ketone was 10/90, thus coating solution (L-6) was prepared. (Preparation of Low Refractive Index Layer Coating Solutions (L-2) to (LS))

Low refractive index layer coating solutions (L-2) to (L-5) were prepared in the same manner as in the preparation of (L-6) except for using dispersions (D-I) to (D-4) in place of dispersion (D-5). (Preparation of Hard Coat Layer Coating Solution (H-I))

De solite Z7404 (94.5 mass parts) (hard coat composition solution containing zirconia fine particles (solids content: 60%), manufactured by JSR) (56.7 mass parts as solids content), 31.3 mass parts of DPHA (UV-curable resin, manufactured by Nippon Kayaku Co., Ltd.), 15.0 mass parts of KBM-5103 (manufactured by Shin-Etsu Chemical Co., Ltd.), 29 mass parts of methyl ethyl ketone, 13 mass parts of methyl isobutyl ketone, 5 mass parts of cyclohexanone, 0.3 mass parts of the following cyanine dye (the above exemplified cyanine dye (I)), and 0.03 mass parts of 4-methoxyphenol (the above exemplified phenolic compound (1-6)) as a discoloration inhibitor were put into a mixing tank and stirred for 30 minutes, whereby hard coat

layer coating solution (H-I) was obtained.

(Manufacture of Antireflection Film (101))

After both surfaces of a polyethylene terephthalate film having a thickness of 102 μm was subjected to corona discharge treatment, latex comprising a styrene-butadiene copolymer was coated on one surface in a thickness of 130 nm to form an undercoat layer.

A gelatin aqueous solution comprising acetic acid and glutaraldehyde was coated on the undercoat layer in a thickness of 50 nm to form a second undercoat layer.

Hard coat layer coating solution (H-I) was coated on the second undercoat layer with a micro gravure roll, dried at 6O ⁰ C for 150 seconds, and the coated layer was cured by irradiation with UV-ray at irradiance of 300 mW/cm ² and irradiation energy dose of 250 mJ/cm ² under nitrogen purge (oxygen concentration: 0.1%) with an air cooled metal halide lamp (manufactured by EYEGRAPHICS Co., Ltd.) of 120 W/cm, whereby a hard coat layer was formed.

On the thus-formed hard coat film (101), low refractive index layer coating solution (L-I) was coated with a micro gravure roll, dried at 12O ⁰ C for 150 seconds, and a low refractive index layer having a thickness of 90 nm was cured by irradiation with UV-ray at irradiance of 400 mW/cm ² and irradiation energy dose of 250 mJ/cm ² under nitrogen purge (oxygen concentration. 0.01%) with an air cooled metal halide lamp (manufactured by EYEGRAPHICS Co., Ltd.) of 240 W/cm, whereby

antireflection film (101) was obtained. The temperature of the surface of the film was adjusted to 6O ⁰ C by the temperature of the metal plate in contact with the rear face of the film. The refractive index of the low refractive index layer after curing was

1.44.

(Manufacture of Antireflection Films (102) to (106))

Antireflection films (102) to (106) were manufactured in the same manner as in the manufacture of antireflection film (101) except for using low refractive index layer coating solutions (L-2) to (L-6) respectively in place of (L-I). (Evaluation of Antireflection Film)

The thus-obtained saponified antireflection films were evaluated as follows. (Evaluation 3: Measurement of average reflectance)

The spectral reflectance of regular reflection at an incident angle of 5° of each film in the wavelength region of from 380 to 780 nm was measured with a spectrophotometer (V-550, manufactured by JASCO Corporation). In the evaluation of spectral reflectance, the average reflectance in 450 to 650 nm was used.

After the rear face of an antireflection film of measuring sample was surface roughening treated, the sample was subjected to light absorption treatment (transmittance at 380 to 780 nm of less than 10%) with black ink, and measurement was carried out on a black stand. (Evaluation 4: Evaluation of color correcting function)

The outermost film of a plasma display panel (PDP-435P, manufactured by Pioneer Corporation) was peeled off, and the rear side of the manufactured antireflection film (the side on which the low refractive index layer is not provided) was stuck with an adhesive in place of it. White light and red light of displayed image were evaluated by visual observation.

A: Improving effect is high.

B: Improving effect is observed.

C: Improving effect is unsatisfactory.

D: Improving effect is not observed.

(Evaluation 5 : Measurement of degree of discoloration inhibition)

The transmittance at the maximum absorption wavelength in the wavelength region of from 520 to 620 nm was measured with a spectrophotometer (MPC-3100, manufactured by Shimadzu Corporation). The degree of discoloration inhibition was computed according to the following expression.

Degree of discoloration inhibition = 100 x (100 - transmittance of antireflection film of the object)/(100 - transmittance of antireflection film

(106))

(Evaluation 6: Evaluation of scratch resistance (durability against rubbing with steel wool))

A rubbing test was carried out with a rubbing tester (AB-301, manufactured by TESTER SANGYO CO., LTD.) on the following conditions.

^• Atmospheric condition of evaluation: 25°C, 60% RH

^• Rubbing material: steel wool (#0000, manufactured by Nihon Steel Wool Co., Ltd.)

Steel wool is wound round the rubbing tip (1 cm x 1 cm) of the tester that is in contact with a sample and fixed with a band.

^• Moving distance (one way): 13 cm

^• Rubbing speed: 13 cm/sec

^• Load: 500 g/cm ² , and 200 g/cm ²

^• Contact area of the tip: 1 cm * 1 cm

^• Number of times of rubbing: 10 round trips

After the nibbing test, the rear face of the measuring sample is subjected to surface roughening treatment, and then to light absorption treatment (transmittance at 380 to 780 nm of less than 10%) with black ink, and the degree of scratch of the rubbed area on the surface side is evaluated by visual observation. A: Scratch is not seen even with careful observation under bright illumination. B: Scratch is seen with careful observation with difficulty under bright illumination. C: Scratch on the antireflection layer is seen with careful observation but is negligible. D: Scratch on the antireflection layer is seen. E: Scratch on the antireflection layer is clearly seen. (Evaluation 7 Evaluation of surface state (uneven coating))

The outermost film of a plasma display panel (PDP-435P, manufactured by Pioneer Corporation) was peeled off, and the rear side of the manufactured antireflection film (the side on which the low refractive index layer is not provided) was stuck with an adhesive in place of it. The display was hidden under bright illumination, and then the antireflection film attached to the front of the surface of the plasma display panel was evaluated.

A: Uneven coating is not seen even with careful observation under bright illumination. B: Uneven coating is seen with careful observation with difficulty under bright illumination.

C: Uneven coating on the antireflection layer is seen with careful observation but is negligible.

D: Uneven coating on the antireflection layer is seen. E: Uneven coating on the antireflection layer is clearly seen. (Results)

The results of evaluations are shown in Table ϊ below.

From the results shown in Table 1, the following things became apparent.

The improving effect of color correction in plasma display panels by the use of a dye (cyanine dye (I)) is high (antireflection films (101) to (106)).

Scratch resistance of antireflection films is improved when inorganic fine particles are used (films (102) to (106)), and in particular, when surface treated inorganic fine particles are used, conspicuous improving effect can be obtained (films (103), (105) and (106)).

In particular, when fine particles having a low refractive index such as porous particles and hollow particles are used, antireflection films also excellent in an antireflection performance (films (104) to (106)) can be obtained.

Further, by the use of the discoloration inhibitor, discoloration of the dye contained in the hard coat layer can be sufficiently inhibited. (Example 2) (Preparation of Low Refractive Index Layer Coating Solution (L-7))

To 100 mass parts of methyl ethyl ketone, 39.4 mass parts of perfluoroolefin copolymer (1), 3.8 mass parts of terminal methacrylate group-containing silicone RMS-033 (manufactured by Gelest), and 3.8 mass parts of photo-radical generator Irgacure 907 (manufactured by Ciba Specialty Chemicals Inc ) were added and dissolved. After that, 165 mass parts of dispersion (D-5) (33.0 mass parts as solids content of silica plus surface treating agent), and 69.0 mass parts of sol component a (20.0 mass parts as solids content) were added to the solution The solution was diluted with cyclohexanone and methyl ethyl ketone so that the concentration of solids content of the coating solution at large was 6 mass% and the ratio of cyclohexanone/methyl ethyl ketone was 10/90, thus coating solution (L-7) was prepared.

(Preparation of Low Refractive Index Layer Coating Solution (L-8))

To 100 mass parts of methyl ethyl ketone, 44.6 mass parts of perfluoroolefin copolymer (1), 4.2 mass parts of terminal methacrylate group-containing silicone RMS-033 (manufactured by Gelest), and 4.2 mass parts of photo-radical generator Irgacure 907 (manufactured by Ciba Specialty Chemicals Inc.) were added and dissolved. After that, 185 mass parts of dispersion (D-5) (37.0 mass parts as solids content of silica plus surface treating agent), and 34.5 mass parts of sol component a (10.0 mass parts as solids content) were added to the solution. The solution was diluted with cyclohexanone and methyl ethyl ketone so that the concentration of solids content of the coating solution at large was 6 mass% and the ratio of cyclohexanone/methyl ethyl ketone was 10/90, thus coating solution (L-8) was prepared. (Preparation of Low Refractive Index Layer Coating Solution (L-9))

To 800 mass parts of Opstar JTA 113 (thermo-crosslinkable fluorine and silicone-containing polymer composition solution (solid content: 6%), manufactured by JSR) (48.0 mass parts as solids content), 160 mass parts of dispersion (D-5) (32.0 mass parts as solids content of silica plus surface treating agent), and 69.0 mass parts of sol component a (20.0 mass parts as solids content) were added. The solution was diluted with cyclohexanone and methyl ethyl ketone so that the concentration of solids content of the coating solution at large was 6 mass% and the ratio of cyclohexanone/methyl ethyl ketone was 10/90, thus coating solution (L-9) was prepared. (Preparation of Low Refractive Index Layer Coating Solution (L-IO))

To 850 mass parts of Opstar JTA 113 (thermo-crosslinkable fluorine and silicone-containing polymer composition solution (solid content: 6%), manufactured

by JSR) (51.0 mass parts as solids content), 170 mass parts of dispersion (D-5) (34.0 mass parts as solids content of silica plus surface treating agent), and 51.7 mass parts of sol component a (15.0 mass parts as solids content) were added. The solution was diluted with cyclohexanone and methyl ethyl ketone so that the concentration of solids content of the coating solution at large was 6 mass% and the ratio of cyclohexanone/methyl ethyl ketone was 10/90, thus coating solution (L-10) was prepared. (Preparation of Low Refractive Index Layer Coating Solution (L-I I))

To 900 mass parts of Opstar JTA 113 (thermo-crosslinkable fluorine and silicone-containing polymer composition solution (solid content: 6%), manufactured by JSR) (54.0 mass parts as solids content), 180 mass parts of dispersion (D-5) (36.0 mass parts as solids content of silica plus surface treating agent), and 34 5 mass parts of sol component a (10.0 mass parts as solids content) were added The solution was diluted with cyclohexanone and methyl ethyl ketone so that the concentration of solids content of the coating solution at large was 6 mass% and the ratio of cyclohexanone/methyl ethyl ketone was 10/90, thus coating solution (L-I l) was prepared (Preparation of Hard Coat Layer Coating Solution (H-2))

De solite Z7404 (88.8 mass parts) (hard coat composition solution containing zirconia fine particles (solids content: 60%), manufactured by JSR) (53 3 mass parts as solids content), 26.7 mass parts of DPHA (UV-curable resin, manufactured by Nippon Kayaku Co., Ltd.), 20 0 mass parts of KBM-5103 (manufactured by Shin-Etsu Chemical Co., Ltd.), 29 mass parts of methyl ethyl ketone, 13 mass parts of methyl isobutyl ketone, 5 mass parts of cyclohexanone, 0 3 mass parts of a cyanine dye (the above exemplified cyanine dye (I)), and 0 03 mass parts of 4-methoxyphenol as a

discoloration inhibitor were put into a mixing tank and stirred for 30 minutes, whereby hard coat layer coating solution (H-2) was obtained. (Preparation of Hard Coat Layer Coating Solution (H-3))

De solite Z7404 (100.0 mass parts) (hard coat composition solution containing zirconia fine particles (solids content: 60%), manufactured by JSR) (60.0 mass parts as solids content), 30.0 mass parts of DPHA (UV-curable resin, manufactured by Nippon Kayaku Co., Ltd.), 10.0 mass parts of KBM-5103 (manufactured by Shin-Etsu Chemical Co., Ltd.), 29 mass parts of methyl ethyl ketone, 13 mass parts of methyl isobutyl ketone, 5 mass parts of cyclohexanone, 0.3 mass parts of a cyanine dye (the above exemplified cyanine dye (I)), and 0.03 mass parts of 4-methoxyphenol as a discoloration inhibitor were put into a mixing tank and stirred for 30 minutes, whereby hard coat layer coating solution (H-3) was obtained. (Manufacture of Antireflection Films (201) to (214))

Antireflection films (201) to (207) were manufactured in the same manner as in the manufacture of antireflection film (101) in Example 1 except for using hard coat layer coating solutions (H-I) to (H-3) as described in Table 2 below in place of (H-I), and using low refractive index layer coating solutions (L-6) to (L-8) as described in Table 2 in place of (L-I).

Further, antireflection films (208) to (214) were manufactured in the same manner as in the manufacture of antireflection film (101) in Example 1 except for using hard coat layer coating solutions (H-I) to (H-3) as described in Table 2 in place of (H-I), using low refractive index layer coating solutions (L-9) to (L-Il) as described in Table 2 in place of (L-I), changing the drying condition of the curing conditions of the low refractive index layer to "12O ⁰ C for 12 minutes", and omitting the heating at 6O ⁰ C from the rear side of the film at the time of UV irradiation

Each of the thus-obtained antireflection films was evaluated in the same manner as in Example 1. (Results)

The results of evaluations are shown in Table 2 below.

From the results shown in Table 2, the following things became apparent.

The higher the content of the organosilane component in the hard coat layer and the low refractive index layer, the higher is the improvement effect of the scratch resistance as the antireflection film.

When the content of the organosilane component in both of the hard coat layer and the low refractive index layer is 15% or more, the scratch resistance reaches sufficient level (films (201), (202), (204), (208), (209) and (211)).

The films using low refractive index layer coating solutions (L-9) to (L-I l) in which thermo-crosslinkable polymer composition solution is used show a little inferior result in the color correction function and the degree of discoloration inhibition (films (208) to (214)) This is presumably due to the fact that longer heating time in the curing condition of the low refractive index layer affects the discoloration of the dye in the hard coat layer. (EXAMPLE 3) (Preparation of Inorganic Fine Particles and Incorporation into Antireflection Film)

Particles having different particle size and refractive index were prepared in the same manner as in the preparation of inorganic fine particle dispersion (P-5) in Example 1 except that the following steps were adjusted.

Particles different in particle size and refractive index were prepared by adjusting the addition amount of silica sol having an average particle size of 5 nm in first preparation process, adjusting the amount of silicic acid solution (SiO ₂ concentration- 3 5 mass%) in second preparation process, or adjusting the amount of tetraethoxysilane, the amount of ammonia, addition timing, temperature, and time in third preparation process

Each of the thus-prepared inorganic fine particle dispersions was subjected to

solvent substitution and surface treatment of inorganic fine particles in accordance with the preparation of dispersion (D-5) in Example 1 to manufacture antireflection films (301) to (308) different only in inorganic fine particles from antireflection film (106) in Example 1 (refer to Table 3).

These antireflection films were evaluated in the same manner as in Example 1. (Results)

The results of evaluations are shown in Table 3 below.

From the results shown in Table 3, the following things became apparent.

By making the particle size of inorganic fine particles larger, surface treatment can be performed while maintaining the refractive index of the fine particles low, so that antireflection films more excellent in antireflection performance can be manufactured. In particular, with the inorganic fine particles having a particle size of 40 nm or more, average refractive index of 1.34 or less can be reached and excellent antireflection property can be exhibited. On the other hand, by making the particle size smaller, the irregularity on the surface is inconspicuous. With the particle size of 85 nm, surface irregularity is hardly generated and, in particular, when the particle size is 75 nm or less, particle size is sufficiently small, so that uniform coating of a low refractive index layer becomes easy and surface irregularity is not generated. (EXAMPLE 4) (Manufacture of Antireflection Films (401) to (409))

Antireflection films (401) to (409) were manufactured in the same manner as in the manufacture of antireflection film (106) in Example 1, except for changing the curing conditions by UV irradiation (oxygen concentration and temperature of film surface) of low refractive index layer coating solutions as shown in Table 4 below.

These antireflection films were evaluated in the same manner as in Example 1. (Results)

The results of evaluations are shown in Table 4 below

From the results shown in Table 4, the following things became apparent.

As the curing conditions of a low refractive index layer, the lower the oxygen concentration, the higher is the scratch resistance improvement (films (401) to (405)).

Further, the higher the film surface temperature, the higher is the scratch resistance improvement (films (402), (406) to (409)).

On the other hand, when the film surface temperature of the curing conditions of the low refractive index layer is high, the function of color correction and the degree of discoloration inhibition show somewhat inferior results (films (408) and (409)).

(EXAMPLE 5)

(Preparation of Hard Coat Layer Coating Solution (H-4))

Hard coat layer coating solution (H-4) was prepared in the same manner as in the preparation of hard coat layer coating solution (H-I) except for changing the discoloration inhibitor of 4-methoxyphenol of hard coat layer coating solution (H-I) to an aniline-based discoloration inhibitor (the above exemplified aniline compound

(II-6))

(Preparation of Hard Coat Layer Coating Solution (H-5))

Hard coat layer coating solution (H-5) was prepared in the same manner as in the preparation of hard coat layer coating solution (H-I) except for changing the discoloration inhibitor of 4-methoxyphenol of hard coat layer coating solution (H-I) to a quinone-based discoloration inhibitor (the above exemplified quinone compound

(iπ-2)).

(Preparation of Hard Coat Layer Coating Solution (H-6))

Hard coat layer coating solution (H-6) was prepared in the same manner as in the preparation of hard coat layer coating solution (H-I) except for changing the discoloration inhibitor of 4-methoxyphenol of hard coat layer coating solution (H-I) to

a piperidine-based discoloration inhibitor (the above exemplified piperidine compound

(IV-2)).

(Preparation of Hard Coat Layer Coating Solution (H-7))

Hard coat layer coating solution (H-7) was prepared in the same manner as in the preparation of hard coat layer coating solution (H-I) except that the discoloration inhibitor of 4-methoxyphenol of hard coat layer coating solution (H-I) was not added.

(Manufacture of Antireflection Films (501) to (508))

Antireflection films (501) to (505) were manufactured in the same manner as in the manufacture of antireflection film (106) in Example 1, except for changing hard coat layer coating solution (H-I) to (H-4) to (H-7) as shown in Table 5 below

Further, antireflection films (506) to (508) were manufactured in the same manner as in the manufacture of antireflection film (106) in Example 1, except for changing the curing conditions by UV irradiation (irradiation energy dose) of hard coat layer coating solutions as shown in Table 5.

These antireflection films were evaluated in the same manner as in Example 1.

(Results)

The results of evaluations are shown in Table 5.

From the results shown in Table 5, the following things became apparent.

By the use of a discoloration inhibitor comprising a phenolic compound, a phenol ether compound, an aniline compound, a quinoline compound, or a piperidine compound, discoloration of the dye contained in the hard coat layer can be sufficiently inhibited, as a result, color correcting function is also satisfactory (films (501) to (505)).

Further, scratch resistance lowers when the dose of UV irradiation as the curing condition of a hard coat layer decreases, and discoloration of the dye contained in the hard coat layer is liable to proceed when the dose of UV irradiation increases (films (506) to (510)). The present application claims foreign priority based on Japanese Patent Application

(JP 2005-370489) filed December 22 of 2005, the contents of which is incorporated herein by reference.