Description Title of Invention: PHOTOPOL YMER RESIN COMPOSITION

Technical Field

[1] The present invention relates to a photopolymer resin composition suitable for forming a light blocking film of a liquid crystal display (hereinafter, referred to as "LCD").

[2]

Background Art

[3] A liquid crystal display device displays images using the optical anisotropy and birefringence of liquid crystal molecules, in which liquid crystal alignment is changed by the application of an electric field, and thus light transmission characteristics are also changed depending on the change of liquid crystal alignment.

[4] Generally, a liquid crystal display device is configured such that two substrates provided with their respective electric field formation electrodes are disposed such that the electrodes face each other, a liquid crystal material is charged between the two substrates, and then a voltage is applied to the electrodes to form an electric field, the electric field moves liquid crystal molecules to change light transmittance, and the change of light transmittance causes the liquid crystal display device to display images.

[5] For example, a commonly-used thin film transistor liquid crystal display (TFT-LCD) includes: a lower substrate, called an array substrate, on which thin film transistors and pixel electrodes are arranged; an upper substrate, called a color filter substrate, which includes a plastic or glass substrate on which black matrices and three-color (red, green and blue) layers are repetitively disposed, an overcoat which is formed on the black matrices and the three color layers, made of polyimide, polyacrylate, polyurethane and the like, have a thickness of 1 to 3 um and serves to protect color filters and maintain surface flatness, and an indium tin oxide (ITO) transparent conductive film which is formed on the overcoat and to which a voltage for driving liquid crystal is applied; and liquid crystal charged between the upper and lower substrates, wherein the upper and lower substrates are provided on both sides thereof with polarizing plates for linearly polarizing visible light (natural light). In the TFT-LCD, an external peripheral circuit applies a voltage to a gate of TFT to allow TFT to turn on, thus converting liquid crystal to the state in which a zero phase voltage can be input to the liquid crystal, and then a zero phase voltage is applied to the liquid crystal to store image information in the liquid crystal, and then the TFT turns off to preserve the electric charge stored in a battery charger or subsidiary battery charger, thereby displaying images for a predetermined period of time. When a voltage is applied to liquid crystal, liquid crystal alignment is changed. At this time, when light penetrates this liquid crystal, the light is diffracted. This diffracted light penetrates the polarizing plate, thus generating the desired images.

[6] The color filter substrate is generally formed by forming black matrices on a transparent plastic or glass substrate and then further sequentially forming red, green and blue color layers having a color pattern, such as a stripe, mosaic or the like, on the transparent plastic or glass substrate using photolithography, a printing method, an ink- jet method or the like.

[7] In the color filter substrate, the black matrices serve to improve contrast by blocking the light such that it doesn t penetrate components other than the transparent pixel electrodes. The red, green and blue color layers thereof serve to determine colors by allowing light having specific wavelengths to pass therethrough. Also, the transparent conductive film thereof serves as a common electrode for applying an electric field to liquid crystal.

[8] FIG. 1 is a schematic sectional view showing a general liquid crystal display device.

As shown in FIG. 1, the general liquid crystal display device (LCD) is manufactured by assembling an array substrate (AS) and a color filter substrate (CS). The array substrate (AS) includes a first transparent substrate 22 defined by a plurality of pixel regions (P), a switching region (S) and a storage region (C), a thin film transistor (T) which is formed on one side of the first transparent substrate 22 and formed corresponding to the switching region (S), pixel electrodes 17 formed corresponding to the plurality of pixel regions (P), and a storage capacitor (Cst) formed corresponding to the storage region (C). The array substrate (AS) further includes a gate wire 13 and a data wire 15 which vertically intersect at one or the other side of the plurality of pixel regions (P).

[9] The thin film transistor (T) includes a gate electrode 32, a semiconductor layer 34 disposed at a position spaced apart from the gate electrode 32, and a source electrode 36 and a drain electrode 38 disposed at positions spaced apart from the semiconductor layer 34.

[10] In the storage capacitor (Cst), a part of the gate wire 13 disposed at the storage region

(C) is used as a first electrode, and an island-shaped metal pattern 30 disposed over the first electrode and brought into contact with the pixel electrode 17 is used as a second electrode.

[11] The color filter substrate (CS) includes a second substrate 5, color filters 7a, 7b and

7c which are formed on one side of the second substrate 5 and formed corresponding to the plurality of pixel regions (P), black matrices 6 which are alternately arranged around the color filters 7a, 7b and 7c, and a common electrode 18 formed beneath the black matrices 6 and the color filters 7a, 7b and 7c. [12] The above-configured array substrate (AS) and color filter substrate (CS) are assembled into a liquid crystal display (LCD) panel.

[13] However, when the LCD panel is fabricated by coupling the color filter substrate 5 with the array substrate 22, there is very great possibility that a light leakage phenomenon occurs due to the error in the coupling of the color filter substrate 5 and the array substrate 22.

[14] Therefore, in order to prevent the light leakage phenomenon from occurring, the black matrices are designed while leaving margins, but these margins become the major cause of a decrease in the opening ratio.

[15] In order to solve the above problems, recently, efforts to increase an opening ratio by forming color filters on an array substrate (which is a lower substrate) instead of a color filter substrate (which is an upper substrate) and to decrease production cost by simplifying a manufacturing process have been actively made.

[16]

Disclosure of Invention Technical Problem

[17] Accordingly, an object of the present invention is to provide a photopolymer resin composition which can exhibit optimum optical density at the time of forming a cured film, and which can be compressed to a predetermined level at the time of applying a predetermined pressure thereto.

[18] Another object of the present invention is to provide a photopolymer resin composition which can exhibit optimum optical density at the time of forming a cured film, and which is highly resistant to a certain chemical.

[19] Still another object of the present invention is to provide a photopolymer resin composition which can be usefully used to form a black matrix and a spacer for maintaining a cell gap on an array substrate on which color filters are formed at the time of manufacturing a liquid crystal display device.

[20] Still another object of the present invention is to provide a photopolymer resin composition which can be usefully used to form the patterns functioning as both a black matrix and a space for maintaining a cell gap.

[21] Still another object of the present invention is to provide a photopolymer resin composition which hinders an applied voltage from being held even when color filters are formed on an array substrate.

[22] Still another object of the present invention is to provide a photopolymer resin composition which hinders an applied voltage from being held because a spacer for maintaining a cell gap, the spacer being formed on an array substrate, is exposed to the inside of a liquid crystal layer when the spacer is made of the composition. [23] Still another object of the present invention is to provide a photopolymer resin composition which can function as a black matrix and a spacer for maintaining a cell gap because it exhibits a sufficient light blocking effect and has resistance to a certain chemical, and which can decrease the number of poor pixels because it does hinder an applied voltage from being held.

[24]

Solution to Problem

[25] An aspect of the present invention provides a photopolymer resin composition, which satisfies the following first and second conditions when a cured film is formed using the photopolymer resin composition:

[26] first condition: the cured film has an optical density (OD) of 3.0 or more per unit thickness of 3.0 μm; and

[27] second condition: when a cured film pattern having a lower width of 25 ~ 40 μm and a thickness of 2.5 ~ 4.0 μm is compressed at a loading rate of 5 ~ 10 mN/sec using a flat indenter having a diameter 50 μm until the compressing force of the flat indenter has reached a maximum compressing force of 5 g _f and is then held for 5 seconds, a depth to which the cured film pattern is compressed is 15 ~ 25% of an initial thickness of the cured film pattern.

[28] Another aspect of the present invention provides a photopolymer resin composition, which is formed into a cured film having a chemical resistance index of 97% or more and an optical density (OD) of 3.0 or more per unit thickness of 3.0 μm, wherein the chemical resistance index is represented as follow:

[29]

Chemical resistance = 100 - [ — — x l OO ]

"3

[30] wherein t ₀ is an initial thickness of a cured film, and ti is a thickness of the cured film obtained by immersing the initial cured film in a resist stripping solution at 6O ⁰ C for 10 minutes and then drying it at 22O ⁰ C for 30 minutes, these two procedures being performed three times.

[31] In the photopolymer resin composition, the resist stripping solution may include, based on the total weight thereof, 4 ~ 12% of tetraethylene glycol, 20 ~ 40% of triophene tetrahydro- 1,1 -dioxide, 10 ~ 20% of diethyleneglycol monoethyl ether, 5 ~ 20% of l-amino-2-propanol, and 30 ~ 50% of l-methyl-2-pyrrolidinone.

[32] The photopolymer resin composition may include an alkali- soluble acrylic binder resin, cardo-based binder resin, a multifunctional monomer having an ethylenic unsaturated double bond, a photopolymerization initiator, and a solvent. Here, the alkali- soluble acrylic binder resin may include an epoxy group. Further, the alkali- soluble acrylic binder resin may have an epoxy equivalent of 200 ~ 2000.

[33] The photopolymer resin composition may further include a colorant including a pigment blend containing two or more kinds of pigments which can express a black color when they are mixed.

[34] In the photopolymer resin composition, the pigment blend essentially includes a red pigment and a blue pigment, and further includes any one selected from among a yellow pigment, a green pigment, a violet pigment and mixtures thereof.

[35] Specifically, the pigment blend may include, based on the solid content of the total weight of the colorant, 10 - 50 wt% of a red pigment, 10 - 50 wt% of a blue pigment, 1 - 20 wt% of a yellow pigment, and 1 - 20 wt% of a green pigment.

[36] Further, the pigment blend may further include, based on the solid content of the total weight of the colorant, 1 - 20 wt% of a violet pigment.

[37] Further, the pigment blend may further include a black pigment, and the amount of the black pigment may be 10 wt% or less based on the solid content of the total weight of the colorant.

[38] In the photopolymer resin composition, the amount of the colorant is 20 - 80 wt% based on the total weight of the composition.

[39] The pigment blend may be a pigment-dispersed solution in which the pigments are dispersed in a solvent.

[40] The pigment-dispersed solution may include at least one acrylate-based pigment dispersant. In this case, the pigment-dispersed solution may include 3 - 20 wt% of a pigment dispersant based on the total weight of the pigment-dispersed solution.

[41] The photopolymer resin composition may further satisfy the following third condition:

[42] third condition: when a cured film pattern having a lower width of 25 - 40 μm and a thickness of 2.5 - 4.0 μm is compressed at a loading rate of 5 - 10 mN/sec using a flat indenter having a diameter 50 μm until the compressing force of the flat indenter has reached a maximum compressing force of 5 g _f , is held for 5 seconds and is then released from the compression, a recovery rate of the compressed cured film pattern, represented by Formula 1 below, is 50% or more.

^[43] Formula 1

Recovery rate = — - x l O O

1

[44] wherein D ₁ is a depth to which the cured film pattern is compressed by external pressure, and D ₂ is a difference between an initial height of the cured film pattern to which the external pressure was not applied and a height of the cured film pattern which was recovered after removing the external pressure.

[45] The photopolymer resin composition may have a voltage holding ratio of 95% or more,

[46] wherein the voltage holding ratio is measured at 25 ⁰ C by charging a pollution source, which is prepared by mixing 2 parts by weight of a cured film sample made of the photopolymer resin composition with 100 parts by weight of liquid crystal and then aging the mixture at 65 ⁰ C for 5 hours, in a voltage holding ratio measuring cell, which is fabricated by assembling a glass substrate including an ITO electrode for applying a voltage formed thereon and a glass substrate including an ITO common electrode formed thereon such that the two glass substrates face each other at a cell gap of 5 μm, and then applying a voltage to the voltage holding ratio measuring cell charged with the pollution source under the condition that the applied voltage has a pulse amplitude of 5 V and a pulse frequency of 60 Hz.

[47] Still another aspect of the present invention provides a thin film transistor substrate including a black matrix formed using the photopolymer resin composition through photolithography.

[48] Still another aspect of the present invention provides a thin film transistor substrate including a spacer for maintaining a cell gap formed using the photopolymer resin composition through photolithography.

[49] Still another aspect of the present invention provides a thin film transistor substrate including a black matrix-integrated spacer for maintaining a cell gap formed using the photopolymer resin composition through photolithography.

[50] Still another aspect of the present invention provides a liquid crystal display device including the thin film transistor as a lower substrate.

Advantageous Effects of Invention

[51] The photopolymer resin composition according to the present invention can be usefully used to form a black matrix and a spacer for maintaining a cell gap on an array substrate on which color filters are formed at the time of manufacturing a liquid crystal display device, and can be usefully used to form the patterns functioning as both a black matrix and a space for maintaining a cell gap.

[52]

Brief Description of Drawings

[53] FIG. 1 is a schematic sectional view showing a general liquid crystal display device; and

[54] FIG. 2 is a schematic view evaluating the compressive characteristics of the cured film pattern made of the photopolymer resin composition of the present invention. [55]

Best Mode for Carrying out the Invention

[56] Hereinafter, preferred embodiments of the present invention will be described in detail.

[57] In a liquid crystal display device, as a part of improving the opening ratio thereof, a lower substrate, that is, an array substrate is provided thereon with a color filter layer, and the color filter layer includes R, G and B pixels and black matrices formed therebetween. Through this configuration, the margin of the black matrices is minimized, so that the opening ratio of the liquid crystal display device is increased, thereby improving the brightness thereof.

[58] Particularly, in the liquid crystal display device, black matrices are formed on an array substrate, and thus a spacer for maintaining a cell gap, called a column spacer, can be also formed on the array substrate. The black matrices and the spacer for maintaining a cell gap may be separately formed through an additional pattern forming process. Generally, a photopolymer resin composition for forming a light blocking film, known as a black matrix, is different from a photopolymer resin composition for forming a spacer for maintaining a cell gap in composition and required properties.

[59] However, in consideration of the advancing technology used to manufacture a liquid crystal display in which color filters are formed on an array substrate, it is required that black matrices and a spacer for maintaining a cell gap are formed such that their heights are each different, when formed through a single photolithography process, and furthermore that a spacer for maintaining a cell gap is formed on black matrices, or black matrices and a spacer for maintaining a cell gap are integrated with each other such that they perform their respective functions when made of just a single pattern.

[60] In order to meet the above requirements, a photopolymer resin composition according to an embodiment of the present invention satisfies the conditions that a cured film made of the composition has an optical density (OD) of 3.0 or more per unit thickness of 3.0 μm, and that, when a cured film pattern having a lower width of 25 ~ 40 μm and a thickness of 2.5 ~ 4.0 μm is compressed at a loading rate of 5 ~ 10 mN/sec using a flat indenter having a diameter 50 μm until the compressing force of the flat indenter has reached a maximum compressing force of 5 g _f and is then held for 5 seconds, the depth to which the cured film pattern is compressed is 15 ~ 25% of the initial thickness of the cured film pattern. Thus, the photopolymer resin composition according to an embodiment of the present invention can be used to form a light blocking film which satisfies minimum light blocking properties and can be compressed to a predetermined level when a predetermined pressure is applied to the light blocking film. [61] When the optical density (OD) per unit thickness of 3.0 μm is less than 3.0, it is difficult to exhibit an optimal light blocking effect even when the thickness of the cured film made of the composition is somewhat increased, and, when the cured film is used as a light blocking film, the light blocking film cannot block the light penetrating other components except for transparent pixel electrodes because it cannot sufficiently exhibit light blocking properties.

[62] Further, in the case where the photopolymer resin composition does not satisfy the above compressive property, when a spacer for maintaining a cell gap, having light blocking properties, is formed on an array substrate using the photopolymer resin composition, it is difficult to uniformalize the thickness difference between a plurality of spacers for maintaining a cell gap in a process of assembling an upper substrate and a lower substrate (array substrate) at the time of manufacturing a liquid crystal display device, with the result that it is difficult to maintain a uniform cell gap, and it is also difficult to obtain a cell gap of a desired size.

[63] Further, considering that a photopolymer resin composition according to an embodiment of the present invention is used to form a spacer for forming a cell gap, it is preferred that the photopolymer resin composition have compression recovery properties in addition to the compressive properties. That is, when the upper and lower substrates are assembled during the LCD fabricating process, it is preferred that, when the spacer for maintaining a cell gap is compressed and then the compressing force is removed therefrom, its height is recovered, thus continuously maintaining the cell gap. In order to meet the above requirements, the photopolymer resin composition according to an embodiment of the present invention further satisfies the condition that when a cured film pattern having a lower width of 25 ~ 40 μm and a thickness of 2.5 ~ 4.0 μm is compressed at a loading rate of 5 ~ 10 mN/sec using a flat indenter having a diameter 50 μm until the compressing force of the flat indenter has reached a maximum compressing force of 5 g _f , is held for 5 seconds and is then released from the compression, a recovery rate of the compressed cured film pattern, represented by Formula 1 below, is 50% or more.

^[64] Formula 1

Recovery rate = — - x l O O

1

[65] wherein D ₁ is a depth to which the cured film pattern is compressed by external pressure, and D ₂ is a difference between the initial height of the cured film pattern to which the external pressure was not applied and the height of the cured film pattern which was recovered after removing the external pressure. [66] Meanwhile, one of the requirements of the above pattern being formed is that the photolithography process being able to be further performed for other purposes after forming the pattern. Taking this into consideration, a photopolymer resin composition, which can be used to make a light blocking film having minimum light blocking properties and resistance to a certain chemical, is required. In order to meet the above requirement, a photopolymer resin composition according to another embodiment of the present invention satisfies the conditions that a cured film made of the composition has an optical density (OD) of 3.0 or more per unit thickness of 3.0 μm and a chemical resistance index of 97% or more, wherein the chemical resistance index is represented as follow:

[67]

Chemical resistance = 100 - [ — — x l OO ]

" D

[68] wherein t ₀ is the thickness of an initial cured film, and ti is the thickness of a cured film obtained by immersing the initial cured film in a resist stripping solution at 6O ⁰ C for 10 minutes and then drying it at 22O ⁰ C for 30 minutes, these two procedures being three times.

[69] Here, the resist stripping solution is defined as a solution for separating and removing unnecessary resist remaining on a wafer after etching in a microfabrication process, and is a chemical selected in consideration of the photolithography process which can be performed after forming black matrices and spacers for maintaining a cell gap on a lower substrate.

[70] One typical example of this resist stripping solution is BAKER PRS-2000.

Specifically, the resist stripping solution includes, based on the total weight thereof, 4 ~ 12% of tetraethylene glycol, 20 ~ 40% of triophene tetrahydro- 1,1 -dioxide, 10 ~ 20% of diethyleneglycol monoethyl ether, 5 ~ 20% of l-amino-2-propanol, and 30 ~ 50% of l-methyl-2-pyrrolidinone. The resist stripping solution is a commercially- available chemical.

[71] When the chemical resistance index is less than 97%, there is a problem in that a column spacer cannot be maintained in a normal pattern during the photoresist and liquid crystal charging processes, and thus cannot sufficiently exhibit functions such as cell gap maintenance and the like which it is supposed to perform.

[72] When the photopolymer resin composition satisfying the above characteristics is used, black matrices and a spacer for maintaining a cell gap may be simultaneously formed so that they are different from each other in height, the heights corresponding to predetermined thickness by patterning the photopolymer resin composition using a slit mask or a half-tone mask, spacers for maintaining a cell gap may be further formed at the positions at which black matrices are formed, or only black matrices may be formed such that they function as spacers for maintaining a cell gap.

[73] Moreover, when the photopolymer resin composition satisfying the above characteristics is used, the damage of the pattern, caused by the resist stripping solution, can be minimized at the time of a subsequent photography process for forming transparent electrodes after forming the pattern.

[74] Meanwhile, as described above, in the liquid crystal display device, a liquid crystal material is charged between two substrates including two respective electrodes (a pixel electrode and a common electrode) and facing each other, a voltage is applied to the two electrodes to generate an electric field, and thus the generated electric field moves liquid crystal molecules to change the light transmission, thereby displaying images. Therefore, when foreign conductive materials are mixed with the liquid crystal material charged between the pixel electrode formed on the lower substrate and the common electrode formed on the upper substrate, the difference in potential between the pixel electrode formed on the lower substrate and the common electrode formed on the upper substrate is not maintained in accordance with the intention of initial voltage application, and thus liquid crystal molecules are not oriented or are oriented differently.

[75] Owing to this problem, bright spots or black spots are generated, thus causing the pixels to be bad.

[76] Meanwhile, in the liquid crystal display device, owing to the non-functionality of liquid crystal orientation and the change of a voltage applied to liquid crystal, the display is also caused to be non-functional. Examples of the non-functionality of the display may include an adherence phenomenon and a white spot phenomenon.

[77] The adherence phenomenon is a phenomenon in which pixels are visibly recognized spotted or are continuously maintained spotted even when they are left for a long time because the transmission rate of pixels to which a voltage is applied and then lowered or shut off is different from that of adjacent pixels to which a voltage is not applied. In the adherence phenomenon of a normal white panel, pixels to which a voltage is applied for a predetermined time look darker than pixels adjacent to the pixels. This adherence phenomenon is known to be caused by the fact that ionic materials adsorbed on electrodes during the application of a voltage continuously influence liquid crystal even when the application of a voltage has been discontinued.

[78] Further, the white spot phenomenon is a phenomenon in which a spotted state is recognized because a part of a display area does not have a transmission rate of 0 when a black image is displayed by the application of a voltage. This white spot phenomenon is thought to be caused by the fact that, since the voltage applied between electrodes must be maintained constant, when ionic materials are present in liquid crystal, the ionic materials move in the liquid crystal to generate an electric current, thus decreasing the potential difference between the electrodes.

[79] The decrease in the potential difference between the electrodes caused by the movement of the ionic materials may have a negative influence on a liquid crystal display device having a structure in which color filters are formed on an array substrate. For this reason, the photopolymer resin composition according to an embodiment of the present invention may have a voltage holding ratio of 95% or more, measured as follows:

[80] the voltage holding ratio is measured at 25 ⁰ C by charging a pollution source, which is prepared by mixing 2 parts by weight of a cured film sample made of the photopolymer resin composition with 100 parts by weight of liquid crystal and the aging the mixture at 65 ⁰ C for 5 hours, in a voltage holding ratio measuring cell, which is fabricated by assembling a glass substrate including an ITO electrode for applying a voltage formed thereon and a glass substrate including an ITO common electrode formed thereon such that the two glass substrates face each other at a cell gap of 5 μm, and then applying a voltage to the voltage holding ratio measuring cell charged with the pollution source under the condition that the applied voltage has a pulse amplitude of 5 V and a pulse frequency of 60 Hz.

[81] When a voltage is applied between the electrodes facing each other in a liquid crystal panel to be charged with an electric charge and then maintained, the loss of voltage results. In this case, a cured film made of the photopolymer resin composition of the present invention may cause the discharge of the electric charge. The level in which a voltage is maintained is defined as a voltage holding ratio . This voltage holding ratio is an important factor necessary for an active element such as a TFT-addressing element in which a voltage must be stored in pixels for a predetermined time. It is ideal for the voltage holding ratio to approximate 100%.

[82] When the voltage holding ratio of the photopolymer resin composition is less than

95%, there are problems in that spots are generated, sensitivity is deteriorated and after images are formed when the photopolymer resin composition is fabricated into a LCD cell.

[83] Considering that the photopolymer resin composition will function as a spacer for maintaining a cell gap, it is advantageous in terms of the exposure of the composition to a liquid crystal layer that the voltage holding ratio of the photopolymer resin composition be 97% or more.

[84] Meanwhile, the photopolymer resin composition according to an embodiment of the present invention includes: an alkali- soluble acrylic binder resin; cardo-based binder resin; a multifunctional monomer having an ethylenic unsaturated double bond; a pho- topolymerization initiator; and a solvent. Preferably, the alkali- soluble acrylic binder resin may include an epoxy group serving to improve compressive characteristics and chemical resistance.

[85] In particular, considering that although the epoxy group included in the alkali-soluble acrylic binder resin serves to improve the resistance to a chemical such as the above resist stripping solution, the developability of the composition is influenced by an excess epoxy equivalent, it is preferred that the alkali-soluble acrylic binder resin have an epoxy equivalent of 200 ~ 2000.

[86] Here, the alkali- soluble acrylic binder resin may be a copolymer prepared by copoly- merizing a monomer including an acid group with a monomer which can be copolymerized with this monomer. The alkali- soluble acrylic binder resin prepared by the copolymerization has a higher film strength than a binder resin prepared by ho- mopolymerization. Further, as the alkali-soluble acrylic binder resin, a polymer compound prepared by the polymer reaction of the copolymer and an ethylenic unsaturated compound including an epoxy group may be used.

[87] Examples of the monomer including an acid group may include (meth)acrylic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid, monomethyl maleic acid, isoprene sulfonic acid, styrene sulfonic acid, 5-norbornene-carboxylic acid, and mixtures thereof.

[88] In particular, in consideration of compressive properties or chemical resistance at the time of forming a cured film, it is preferred that a binder resin including an epoxy group be used. For this reason, at the time of preparing an alkali- soluble resin, a monomer including epoxy group may be used in combination with the monomer including an acid group.

[89] Examples of the monomer including an epoxy group may include, but are not limited to, glycidyl acrylate, glycidyl methacrylate, glycidyl α-ethyl acrylate, glycidyl α- n-propyl acylate, glycidyl α-n-butyl acrylate, acrylic acid-3,4-epoxy butyl, methacrylic acid-3,4-epoxy butyl, acrylic acid-6,7-epoxy heptyl, methacrylic acid-6,7-epoxy heptyl, α-ethyl acrylic acid-6,7-epoxy heptyl, o-vinlybenzyl glycidyl ether, m- vinlybenzyl glycidyl ether, p-vinlybenzyl glycidyl ether, and the like. The amount of the monomer including an epoxy group may be determined in consideration of the above epoxy equivalent.

[90] The alkali-soluble acrylic binder resin may be used in an amount of 1 ~ 40 wt%, preferably 20 ~ 30 wt%, based on the total solid content of the photopolymer resin composition.

[91] Meanwhile, when a photopolymer resin composition is prepared using only the alkali- soluble acrylic binder resin, a large amount of a multifunctional monomer must be used to form a light blocking film having a thickness of 2.5 μm, which causes surface curing is rapidly conducted due to photocuring, with the result that wrinkles are formed at the time of thermal photocuring. For this reason, the photopolymer resin composition according to an embodiment of the present invention may include a cardo- based compound as a binder resin. This cardo-based binder resin is referred to as an acrylate-based binder resin having a main chain provided with a fluorine group, and is not structurally limited.

[92] An example of the cardo-based compound is represented by Chemical Formula 1 below:

[93] Chemical Formula 1

[95] wherein, X may be represented by;

[96]

0

[97] Y may be a residue of an acid anhydride selected from among maleic anhydride, succinic anhydride, cis-l,2,3,6-tetrahydrophthalic anhydride, 3,4,5, 6-tetrahydrophthalic anhydride, phthalic anhydride, itaconic anhydride, 1,2,4- 1,2,4-benzenetricarboxylic anhydride, methyl-tetrahydrophthalic anhydride, citraconic anhydride, 2,3-dimethylmaleic anhydride, l-cyclopentene-l,2-dicarboxylic anhydride, cis-5-norbonene-endo-2,3-dicarboxylic anhydride and 1,8-naphthalic anhydride; and Z may be a residue of an acid dianhydride selected from among 1,2,4,5-bezenetetracarboxylic dianhydride, 4,4'-biphthalic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, pyromelitic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 1,2,4,5-tetracarboxylic anhydide, methylnorbonene-2,3-dicarboxylic anhydride, 4,4'-[2,2,2-trifluoro-l-(Trifluoromethyl)ethylidene]diphthal ic anhydride, 4,4 ^v -oxydiphthalic anhydride, and ethylene glycol bis (anhydro trimelitate).

[98] The cardo-based compound may be used in an amount of 1 ~ 40 wt%, preferably 20

~ 30 wt%, based on the total solid content of the photopolymer resin composition.

[99] However, when a photopolymer resin composition is prepared using only the cardo- based compound, in the formation of a light blocking film having a thickness of 2.5 μm, the cardo-based compound is reacted with a multifunctional monomer having an ethylenic unsaturated double bond to accelerate surface curing, and thus wrinkles may be formed due to internal shrinkage at the time of thermal photocuring.

[100] The photopolymer resin composition according to an embodiment of the present invention may include a multifunctional monomer having an ethylenic unsaturated double bond. This multifunctional monomer serves to form a photoresist phase using light. For example, the multifunctional monomer may be any one selected from the group consisting of propyleneglycol methacrylate, dipentaerythritol hexacrylate, dipen- taerythritol acrylate, neopentylglycol diacrylate, 1,6-hexanediol diacrylate, 1,6-hexanediol acrylate, tetraethyleneglycol methacrylate, bisphenoxyethyl alcohol diacrylate, trishydroxyethylisocyanurate trimethacrylate, trimethylpropane trimethacrylate, pentaerythritol trimethacrylate, pentaerythritol tetramethacrylate, dipentaerythritol hexamethacrylate, and mixtures thereof.

[101] It is preferred that the amount of the multifunctional monomer be 0.1 ~ 99 parts by weight based on 100 parts by weight of the cardo-based compound from a viewpoint that the adhesion force between pigment and particle composition is increased by the cross-linkage attributable to the radical reaction of a photoinitiator using UV, thus increasing optical density.

[102] The photopolymer resin composition according to an embodiment of the present invention may include a photopolymerization initiator. For example, the photopoly- merization initiator may be selected from among: oxime esters, such as l-[9-ethyl-6-(2-methybenzoyl)-9H-carbazole-3-yl]-l-(O-acetyl oxime), l,2-octanedione-l[(4-phenylthio)phenyl]-2-benzoyl-oxime, and the like; ketones, such as thioxanthone, 2,4-diethyl thioxanthone, thioxanthone-4-sulfonic acid, ben- zophenone, 4,4'-bis(diethylamino)benzophenone, acetophenone, p- dimethylaminoacetophenone, dimethoxyacetoxybenzophenone, 2,2'-dimethoxy-2-phenylacetophenone, p-methoxyacetophenone, 2-methyl[4-(methylthio)phenyl]-2-morpholino-l-propanone, 2-benzyl-2-diethylamino- 1 -(4-morpholinophenyl) -butane- 1 -one, 2-hydroxy-2-methyl- 1 -phenylpropane- 1 -one,

4-(2-hydroxyethoxyl)phenyl-(2-hydroxy-2-propyl)ketone, 1-hydroxycyclohexy Ike tone, and the like; quinones, such as anthraquinone, 1,4-naphthoquinone, and the like; halogen compounds, such as l,3,5-tris(trichloromethyl)-s-triazine, l,3-bis(trichloromethyl)-5-(2-chlorophenyl)-s-triazine, l,3-bis(trichlorophenyl)-s-triazine, phenacyl chloride, tribromomethyl phenylsulfone, tris(trichloromethyl)-s-triazine and the like; peroxides, such as di-t-butyl peroxide, and the like; and acylphosphine oxides, such as 2,4,6-trimethylbenzoyldiphenylphosphine oxide and the like.

[103] It is preferred that the photopolymerization initiator be used in an amount of 1 ~ 30 wt% based on the total photopolymer resin composition.

[104] The photopolymer resin composition according to an embodiment of the present invention may include a solvent. For example, the solvent may be selected from among propylene glycol methyl ether acetate (PGMEA), propylene glycol ethyl ether acetate (PGEEA), propylene glycol methyl ether, propylene glycol propyl ether, methyl cellosolve acetate, ethyl cellosolve acetate, diethyl glycol methyl acetate, ethyl ethoxy propionate, methyl ethoxy propionate, butyl acetate, ethyl acetate, cyclohexanone, acetone, methyl isobutyl ketone, dimethyl formamide, N,N" -dimethyl acetamide, N- methyl pyrrolidinone, dipropylene glycol methyl ether, toluene, methyl cellosolve, and ethyl cellosolve.

[105] The amount of the solvent may be 20 ~ 60 wt% based on the total photopolymer resin composition. In addition, if necessary, a general additive may be added.

[106] Meanwhile, the voltage holding ratio can be controlled by adjusting the content ratio of organic/inorganic pigments or by adjusting the kind and content of a pigment dispersant.

[107] The photopolymer resin composition according to an embodiment of the present invention may include a colorant including a pigment blend containing two or more kinds of pigments which can express a black color when they are mixed.

[108] Generally, a photopolymer resin composition for realizing light blocking properties may include a black pigment. For example, carbon black or titan black may be used as the black pigment. However, when light blocking properties are realized using the black pigment, the black pigment, such as carbon black or titan black, acts as an ionic impurity. Therefore, the cured film obtained using the black pigment has poor compressive characteristics, which is not preferable.

[109] For this reason, the photopolymer resin composition according to an embodiment of the present invention expresses an actual black color using the pigment blend. Here, the expression "actual black color" means a black color which can absorb light over the entire wavelength of a visible region (380 ~ 780 nm) based on the UV-spectrum.

[110] Preferably, the mixing of pigments may be performed by dispersing the pigment blend in a solvent to form a pigment-dispersed solution.

[I l l] When the pigments are mixed, it is preferred that organic pigments are added in consideration of the light transmission rate and the dielectric constant. The pigment blend may essentially include a red pigment and a blue pigment, and may further include a yellow pigment or a green pigment. In addition, the pigment blend may further include a violet pigment.

[112] Examples of the pigments includes, based on color index (C.I.), red pigments of C.I. 3, 23, 97, 108, 122, 139, 149, 166, 168, 175, 177, 180, 185, 190, 202, 214, 215, 220, 224, 230, 235, 242, 254, 255, 260, 262, 264, 272; yellow pigments of C.I. 13, 35, 53, 83, 93, 110, 120, 138, 139, 150, 154, 175, 180, 181, 185, 194, 213; blue pigments of C.I. 15, 15:1, 15:3, 15:6, 36, 71, 75; green pigments of C.I. 7, 36; and violet pigments of C.I. 15, 19, 23, 29, 32, 37.

[113] Further, if necessary, a high-resistance black pigment may be added. Examples of the black pigment may include, but are not limited to, carbon black, titan black and the like.

[114] This pigment blend may include, based on the solid content of the total weight of the colorant, 10 - 50 wt% of a red pigment, 10 - 50 wt% of a blue pigment, 1 - 20 wt% of a yellow pigment, and 1 - 20 wt% of a green pigment. Here, the pigment blend may further include, based on the solid content of the total weight of the colorant, 1 - 20 wt% of a violet pigment. Further, the pigment blend may further include, based on the solid content of the total weight of the colorant, 10 wt% or less of a violet pigment. Since the black pigment has electroconductivity, there are problems in that the dielectric constant of a cured film is increased and the compressive characteristics of the cured film are deteriorated. Therefore, it preferred that the black pigment be a high- resistance pigment, and it is more preferred that the black pigment be used in an amount of 5 wt% or less based on the solid content of the total weight of the colorant.

[115] Meanwhile, the voltage holding ratio of the light blocking film composed of the pho- topolymer resin composition can be changed depending on the degree of dispersion of a pigment. For this reason, the colorant may include a pigment dispersant. Examples of the pigment dispersant may include: polymer dispersants, such as modified polyurethane, modified polyacrylate, modified polyester, modified polyamide and the like; and surfactants, such as phosphoric acid ester, polyester, alkylamine, and the like. Among them, acrylate -based pigment dispersants, for example, Disperbyk-2000, Disperbyk-2001, LP-N-21116 and LP-N-21208 manufactured by BYK chemie Corporation, and EFKA-4300, EFKA-4330, EFKA-4340, EFKA-4400, EFKA-4401, EFKA-4402, EFKA-4046 or EFKA-4060 manufactured by Ciba Corporation, can be more advantageous in terms of a voltage holding ratio.

[116] However, when the pigment dispersant is excessively added, the dispersion stability of the pigment can be deteriorated, and the voltage holding ratio of the light blocking film can be decreased due to the degeneration of certain functional groups. For this reason, it is preferred that the amount of the pigment dispersant be 3 - 20 wt% based on the total amount of the dispersion-type colorant, that is the pigment-dispersed solution.

[117] It is preferred that the amount of the colorant be 20 ~ 80 wt%, more preferably, 30 ~ 66 wt% based on the total amount of the photopolymer resin composition. When the amount of the colorant is less than 20 wt%, the optical density of the formed light blocking film is too low, and thus the light blocking film cannot exhibit sufficient light blocking ability. In contrast, when the amount of the colorant is more than 80 wt%, there are problems in that the amount of the components constituting the photopolymer resin composition decreases, and the photopolymer resin composition is not sufficiently cured, thus deteriorating developability, and in that residues are formed.

[118] Such a photopolymer resin composition may be prepared by mixing (a) a pigment blend, (b) an alkali-soluble acrylic binder resin, (c) a cardo-based compound, (d) a multifunctional monomer having an ethylenic unsaturated double bond, (e) a pho- topolymerization initiator and, if necessary, an organic additive with a solvent, stirring the mixture and then filtering the stirred mixture using a membrane filter having a thickness of 5 μm.

[119] The photopolymer resin composition prepared in this way is applied on a glass substrate having a clean surface or a glass substrate including a transparent electrode layer (for example, a glass substrate deposited with ITO or IZO) using a non-contact type applicator such as a spin coater (a rotary applicator), a slit coater (a non-rotary applicator) or the like.

[120] In the preparation and application of the photopolymer resin composition, in order to improve the adhesion between the glass substrate and the photopolymer resin composition, a silane coupling agent may be combined with the photopolymer resin composition or may be applied on the glass substrate.

[121] After the application of the photopolymer resin composition, the photopolymer resin composition applied on the glass substrate is dried at a temperature of 80 ~ 12O ⁰ C, preferably 90 ~ 100 ⁰ C, for 60 ~ 150 seconds using a hot plate), is left at room temperature for several hours ~ several days or is heated for several minutes ~ several hours using a warm air heater or an infrared heater to remove the solvent (so called, a pre-baking process), thereby forming a film having a thickness of 2 ~ 5 μm. Subsequently, the film is exposed by active energy rays such as ultraviolet rays at an energy radiation rate of 30~1000mJ/cm ² using a mask. In this case, the energy radiation rate may be changed depending on the kind of a photopolymer resin composition used to form a light blocking film. Then, the exposed film is developed using a dipping method or a spray method to form a cured film pattern. The developer may be selected from among organic developers, such as monoethanolamine, di- ethanolamine, triethanolamine and the like, and inorganic developers, such as aqueous solutions of sodium hydroxide, potassium hydroxide, ammonia, quaternary ammonium salt and the like.

[122] After the development of the exposed film, a post-baking process may be performed at a temperature of 150 ~ 25O ⁰ C for 20 ~ 40 minutes.

[123] Since the cured film obtained in this way has suitable light blocking properties and compressive characteristics, it can be usefully used to manufacture a liquid crystal display device having a structure in which color filters are formed on a thin film transistor substrate, that is, an array substrate.

[124]

Mode for the Invention

[125] Hereinafter, the present invention will be described in more detail with reference to the following Examples. However, the scope of the present invention is not limited thereto.

[126] Preparation Example 1: Synthesis of alkali-soluble acrylic binder resin

[127] 40 g of methacrylic acid, 130 g of benzyl methacrylate, 20 g of glycidyl methacrylate, 500 g of propylene glycol monomethyl ether acetate and 25 g of azobi- sisobutylonitrile were put into a 1000 mL four-neck flask, and were then stirred for 30 minutes while blowing nitrogen into the flask. Subsequently, the resulting mixture was slowly heated to 7O ⁰ C and then reacted at this temperature for 6 hours, and was then heated to 8O ⁰ C and then further reacted at this temperature for 2 hours, thereby synthesizing an alkali-soluble acrylic binder resin (epoxy equivalent: 2500).

[128]

[129] Preparation Example 2: Synthesis of alkali-soluble acrylic binder resin

[130] 30 g of methacrylic acid, 130 g of glycidyl methacrylate, 15 g of styrene, 10 g of

3-(methacryloxypropyl)trimethoxysilane, 500 g of propylene glycol monomethyl ether acetate and 25 g of azobisisobutylonitrile were put into a 1000 mL four- neck flask, and were then stirred for 30 minutes while blowing nitrogen into the flask. Subsequently, the resulting mixture was slowly heated to 7O ⁰ C and then reacted at this temperature for 6 hours, and was then heated to 8O ⁰ C and then further reacted at this temperature for 2 hours, thereby synthesizing an alkali- soluble acrylic binder resin (epoxy equivalent: 600).

[131]

[132] Preparation Example 3: Synthesis of cardo-based compound

[133] 58 g of a bisphenol fluorene type epoxy resin (epoxy equivalent: 232), 313 g of propylene glycol monomethyl ether acetate, 2.5 g of triethylbenzyl ammonium chloride, 0.03 g of hydroquinone and 18 g of acrylic acid were put into a 500 mL four- neck flask, and were then heated to 80 ~ 9O ⁰ C and then melted while injecting nitrogen into the flask at a flow rate of 25 mL/min. Subsequently, the resulting mixture was slowly heated to 8O ⁰ C and thus completely melted. The resulting product was continuously heated and stirred until its acid value became less than 1.0 mgKOH/g. In this case, it took its acid value 12 hours to become a target acid value. Subsequently, the resulting product was cooled to room temperature to obtain a colorless, transparent bisphenol fluorene type epoxy acrylate.

[134] Subsequently, 300 g of the obtained bisphenol fluorene type epoxy acrylate was mixed with 14 g of 1,2,3,6-tetrahydro-phthalic anhydride, 0.3 g of 3,3',4,4'-biphenylcarboxylic dianhydride and 0.76 g of tetraethyl ammonium bromide, and was then slowly heated to 130 ~ 14O ⁰ C and then reacted at this temperature for 15 hours to obtain a cardo-based compound.

[135]

[136] <Example 1>

[137] The amount of each component of the photopolymer resin compositions according to the following Examples and Comparative Examples is represented by a relative weight based on 100 parts by weight of a cardo-based compound.

[138] 100 parts by weight of the cardo-based compound (Preparation Example 3), 5 parts by weight of the alkali-soluble acrylic binder resin (Preparation Example 1), 130 parts by weight of a pigment-dispersed solution (KLB K-90, manufactured by Mikuni Corporation, 20 wt% of solid content, including 5 wt% of a pigment dispersant (disperbyk-2001, manufactured by BYK Corporation) based on the total amount of the pigment-dispersed solution), 2 parts by weight of a multifunctional monomer (dipentaerythritol hexacrylate) and 5.2 parts by weight of a photopolymerization initiator were mixed with 90 parts by weight of a solvent (propylene glycol methyl ether acetate (PGMEA)) and 1 part by weight of other additives (fluorine-based surfactant and coupling agent), which were then stirred for 3 hours to prepare a photopolymer resin composition.

[139] The prepared photopolymer resin composition was formed into a cured film pattern through the following processes. First, the photopolymer resin composition was applied on an IZO-deposited glass substrate having a clean surface using a spin coater at a spin speed of 270 rpm to form a resin coating layer. Thereafter, the resin coating layer was dried at 9O ⁰ C for 150 seconds using a hot plate to have a thickness of 3.5 μm. Subsequently, the dried resin coating layer was exposed to active energy rays such as ultraviolet rays at an energy radiation rate of 60 mJ/cm ² using a mask (gap: 200 μm). Then, the exposed resin coating layer was developed for 100 seconds using a developer (0.04% KOH, 23 ⁰ C) to form a cured film pattern.

[140] After the development of the exposed resin coating layer, a post-baking process was performed at a temperature of 22O ⁰ C for 30 minutes. [141]

[142] (1) Method of measuring the optical density of the cured film formed of the pho- topolvmer resin composition

[143] The optical density of the formed cured film was measured using a PMT manufactured by Otsuka Electronics Co., Ltd., in such a manner as to compare the cured film with a reference specimen having an optical density of 2.4, and the results thereof are given in Table 1.

[144]

[145] (2) Method of measuring the compressive properties of the cured film formed of the photopolvmer resin composition

[146] The compressive properties of the cured film pattern were measured using 'Load- Unload test' items using a micro compression hardness tester (DUH-W201S, manufactured by Shimadzu Corp. in JAPAN), and the results thereof are given in Table 1.

[147] Specific measurement conditions are as follows.

[148] a. Maximum compression force: 5 g _f

[149] b. Compression force per second: 6.2 mN/sec

[150] c. Holding period at maximum compression force: 5 sec.

[151] FIG. 2 is a schematic view showing the method used to measure the compressive properties of the cured film pattern. As shown in FIG. 2, the cured film pattern starts to be loaded using a flat indenter having a diameter of 50 μm, and is then continuously loaded until its compressing force has reached the maximum compressing force. At this time, when the loaded cured film pattern is held for a predetermined time, the cured film pattern is compressed. In this case, the depth to which the cured film pattern is compressed is designated by "D ₁ ".

[152] Thereafter, the cured film pattern is recovered to a predetermined height when the flat indenter is removed (unloaded). In this case, the difference between the initial height (T) of the cured film pattern to which the external pressure as not applied and the height of the cured film pattern which was recovered after removing the external pressure is designated as "D ₂ ".

[153] The recovery rate of the cured film pattern to compression is calculated by Formula 1 below.

^[154] Formula 1

Recovery rate = — - x l O O

1

[155] All of the results thereof are represented by an average value of the recovery rates which were measured five times. [156]

[157] (3) Method of measuring the voltage holding ratio of the cured film formed of the photopolvmer resin composition

[158] A voltage holding ratio measuring cell (manufactured by EHC Corp.) fabricated by assembling a glass substrate (size: lcmxlcm) including an ITO electrode for applying a voltage formed thereon and a glass substrate (size: lcmxlcm) including an ITO common electrode formed thereon such that the two glass substrates face each other at a cell gap of 5 μm was provided.

[159] Meanwhile, a pollution source was prepared by scratching the cured film and then mixing 0.02 g of the scratched cured film sample with 1 g of liquid crystal (MLC-7022-100, manufactured by Merck Corp.) in a test tube and then aging the mixture at 65 ⁰ C for 5 hours.

[160] The prepared pollution source was charged in the voltage holding ratio measuring cell, and then a voltage was applied thereto under the following conditions:

[161] - Pulse amplitude: 5 V

[162] - Pulse frequency: 60Hz

[163] - Pulse width: 16.6 msec.

[164] Then, the voltage holding ratio of the pollution source was measured under the above conditions, and the results thereof are given in Table 1.

[165] The voltage holding ratio thereof was measured at a temperature of 25 ⁰ C using a Model 6245C manufactured by TOYO Corporation.

[166]

[167] (4) Method of measuring the chemical resistance index of the cured film formed of the photopolvmer resin composition

[168] The initial thickness of a cured film pattern was measured using a 3D profiler (non-contact type thickness measuring device), and was designated as "t ₀

[169] Subsequently, the cured film pattern was put into a 500 mL beaker filled with 300 mL of BAKER PRS-2000, immersed at 6O ⁰ C for 10 minutes, dried at 22O ⁰ C for 20 minutes, and then the thickness of the cured film pattern was measured using the above method. In this way, the cured film pattern was immersed, dried, and then the thickness thereof was measured again. These procedures were repeated three times. The thickness of the cured film pattern measured three times is designated by "t/ ¹ .

[170] The chemical resistance index of the cured film pattern was calculated using the measured values and the following Formula:

[171] Chemical resistance = 100 - [ — — x l OO ] t ".3

[172]

[173] <Example 2>

[174] A photopolymer resin composition was prepared using the same composition and method as in Example 1, except that 20 parts by weight of an alkali-soluble acrylic binder resin and 100 parts by weight of a cardo-based compound were used.

[175] A cured film was formed using the same method as in Example 1, and then the properties of the cured film were also evaluated using the same method as in Example 1. The results thereof are given in Table 1 and Table 2 below.

[176]

[177] <Example 3>

[178] A photopolymer resin composition was prepared using the same composition and method as in Example 1, except that 50 parts by weight of an alkali-soluble acrylic binder resin and 100 parts by weight of a cardo-based compound were used.

[179] A cured film was formed using the same method as in Example 1, and then the properties of the cured film were also evaluated using the same method as in Example 1. The results thereof are given in Table 1 and Table 2 below.

[180]

[181] <Example 4>

[182] A photopolymer resin composition was prepared by adding 5 parts by weight of a carbon black pigment-dispersed solution (KLBK-61, manufactured by Mikuni Corporation, 25 wt% of solid content, including 5 wt% of a pigment dispersant (disperbyk-2001, manufactured by BYK Corporation) based on the total amount of the pigment-dispersed solution) to the pigment blend of Example 1.

[183] A cured film was formed using the same method as in Example 1, and then the properties of the cured film were also evaluated using the same method as in Example 1. The results thereof are given in Table 1 and Table 2 below.

[184]

[185] <Example 5>

[186] A photopolymer resin composition was prepared using the same composition as in Example 1, except that 10 parts by weight of the carbon black pigment of Example 4 were used.

[187] A cured film was formed using the same method as in Example 1, and then the properties of the cured film were also evaluated using the same method as in Example 1. The results thereof are given in Table 1 and Table 2 below. [188]

[189] <Example 6> [190] A photopolymer resin composition was prepared using the same composition as in

Example 1, except that 15 parts by weight of the carbon black pigment of Example 4 were used. [191] A cured film was formed using the same method as in Example 1, and then the properties of the cured film were also evaluated using the same method as in Example

1. The results thereof are given in Table 1 and Table 2 below. [192]

[193] <Example 7> [194] A photopolymer resin composition was prepared using the same method as in

Example 1, except that the alkali- soluble acrylic binder resin obtained from

Preparation Example 2 was used instead of the alkali- soluble acrylic binder resin obtained from Preparation Example 1. [195] A cured film was formed using the same method as in Example 1, and then the properties of the cured film were also evaluated using the same method as in Example

1. The results thereof are given in Table 1 and Table 2 below. [196]

[197] <Example 8> [198] A photopolymer resin composition was prepared using the same composition and method as in Example 7, except that 20 parts by weight of an alkali-soluble acrylic binder resin and 100 parts by weight of a cardo-based compound were used. [199] A cured film was formed using the same method as in Example 1, and then the properties of the cured film were also evaluated using the same method as in Example

1. The results thereof are given in Table 1 and Table 2 below.

[Table 1]

[200] From Table 1, it can be seen that since the cured film patterns formed of the pho- topolymer resin compositions according to embodiments of the present invention can be compressed to a predetermined thickness when a predetermined force is applied thereto and have enough optical density to exhibit a light blocking effect, they can be usefully used to form patterns for exhibiting a light blocking effect and maintaining a cell gap.

[201] Further, it can be seen that since the cured film patterns formed of the photopolymer resin compositions according to embodiments of the present invention can be thickly formed on an IZO-deposited film, they can sufficiently function as a spacer for maintaining a cell gap, and that since they have a high voltage holding ratio, poor images are not displayed even when they are exposed to a liquid crystal layer, and thus they can be usefully used as a spacer for maintaining a cell gap.

[202] From Table 2, it can be seen that since the cured films formed of the photopolymer resin compositions according to embodiments of the present invention have a chemical resistance index of preferably, 97% or more, the cured films, functioning as black matrices and/or spacers for maintaining a cell gap, are not lost, and thus the photopolymer resin composition of the present invention can be usefully used to fabricate a liquid crystal display device in which black matrices and/or spacers for maintaining a cell gap are formed on a lower substrate.

[203] [204] Preparation Example 4: Synthesis of alkali-soluble acrylic binder resin [205] 40 g of methacrylic acid, 130 g of benzyl methacrylate, 60 g of glycidyl methacrylate, 500 g of propylene glycol monomethyl ether acetate and 25 g of azobi- sisobutylonitrile were put into a 1000 mL four-neck flask, and were then stirred for 30 minutes while blowing nitrogen into the flask. Subsequently, the resulting mixture was slowly heated to 7O ⁰ C and then reacted at this temperature for 6 hours, and was then heated to 8O ⁰ C and then further reacted at this temperature for 2 hours, thereby synthesizing an alkali-soluble acrylic binder resin (epoxy equivalent: 400).

[206] [207] Preparation Example 5: Synthesis of alkali-soluble acrylic binder resin [208] 30 g of methacrylic acid, 130 g of glycidyl methacrylate, 20 g of styrene, 10 g of 3-(methacryloxypropyl)trimethoxysilane, 500 g of propylene glycol monomethyl ether acetate and 25 g of azobisisobutylonitrile were put into a 1000 mL four- neck flask, and were then stirred for 30 minutes while blowing nitrogen into the flask. Subsequently, the resulting mixture was slowly heated to 7O ⁰ C and then reacted at this temperature for 6 hours, and was then heated to 8O ⁰ C and then further reacted at this temperature for 2 hours, thereby synthesizing an alkali- soluble acrylic binder resin (epoxy equivalent: 600).

[209]

[210] Preparation Example 6: Synthesis of alkali-soluble acrylic binder resin

[211] 40 g of methacrylic acid, 170 g of benzyl methacrylate, 20 g of glycidyl methacrylate, 500 g of propylene glycol monomethyl ether acetate and 25 g of azobi- sisobutylonitrile were put into a 1000 mL four-neck flask, and were then stirred for 30 minutes while blowing nitrogen into the flask. Subsequently, the resulting mixture was slowly heated to 7O ⁰ C and then reacted at this temperature for 6 hours, and was then heated to 8O ⁰ C and then further reacted at this temperature for 2 hours, thereby synthesizing an alkali-soluble acrylic binder resin (epoxy equivalent: 2500).

[212]

[213] Preparation Example 7: Synthesis of alkali-soluble acrylic binder resin

[214] 60 g of methacrylic acid, 170 g of benzyl methacrylate, 500 g of propylene glycol monomethyl ether acetate and 25 g of azobisisobutylonitrile were put into a 1000 mL four-neck flask, and were then stirred for 30 minutes while blowing nitrogen into the flask. Subsequently, the resulting mixture was slowly heated to 7O ⁰ C and then reacted at this temperature for 6 hours, and was then heated to 8O ⁰ C and then further reacted at this temperature for 2 hours, thereby synthesizing an alkali- soluble acrylic binder resin.

[215]

[216] <Example 9>

[217] The amount of each component of the photopolymer resin compositions according to the following Examples and Comparative Examples is represented by a relative weight based on 100 parts by weight of a cardo-based compound.

[218] 100 parts by weight of the cardo-based compound (Preparation Example 3), 5 parts by weight of the alkali-soluble acrylic binder resin (Preparation Example 4), 130 parts by weight of a pigment-dispersed solution (KLB K-90, manufactured by Mikuni Corporation, 20 wt% of solid content, including 5 wt% of a pigment dispersant (disperbyk-2001, manufactured by BYK Corporation) based on the total amount of the pigment-dispersed solution), 2 parts by weight of a multifunctional monomer (dipentaerythritol hexacrylate) and 5.2 parts by weight of a photopolymerization initiator were mixed with 90 parts by weight of a solvent (propylene glycol methyl ether acetate (PGMEA)) and 1 part by weight of other additives (fluorine-based surfactant and coupling agent), which were then stirred for 3 hours to prepare a photopolymer resin composition.

[219] A cured film was formed using the same method as in Example 1, and then the properties of the cured film were also evaluated using the same method as in Example 1. The results thereof are given in Table 3 and Table 4 below.

[220]

[221] <Example 10>

[222] A photopolymer resin composition was prepared using the same composition and method as in Example 9, except that 20 parts by weight of an alkali-soluble acrylic binder resin and 100 parts by weight of a cardo-based compound were used.

[223] A cured film was formed using the same method as in Example 1, and then the properties of the cured film were also evaluated using the same method as in Example 1. The results thereof are given in Table 3 and Table 4 below.

[224]

[225] <Example l l>

[226] A photopolymer resin composition was prepared using the same composition and method as in Example 9, except that 50 parts by weight of an alkali-soluble acrylic binder resin and 100 parts by weight of a cardo-based compound were used.

[227] A cured film was formed using the same method as in Example 1, and then the properties of the cured film were also evaluated using the same method as in Example 1. The results thereof are given in Table 3 and Table 4 below.

[228]

[229] <Example 12>

[230] A photopolymer resin composition was prepared by adding 5 parts by weight of a carbon black pigment-dispersed solution (KLBK-61, manufactured by Mikuni Corporation, 25 wt% of solid content, including 5 wt% of a pigment dispersant (disperbyk-2001, manufactured by BYK Corporation) based on the total amount of the pigment-dispersed solution) to the pigment blend of Example 9. A cured film was formed using the same method as in Example 1, and then the properties of the cured film were also evaluated using the same method as in Example 1. The results thereof are given in Table 3 and Table 4 below.

[231]

[232] <Example 13>

[233] A photopolymer resin composition was prepared using the same composition as in Example 9, except that 10 parts by weight of the carbon black pigment of Example 12 were used.

[234] A cured film was formed using the same method as in Example 1, and then the properties of the cured film were also evaluated using the same method as in Example 1. The results thereof are given in Table 3 and Table 4 below.

[235]

[236] <Example 14> [237] A photopolymer resin composition was prepared using the same composition as in

Example 9, except that 15 parts by weight of the carbon black pigment of Example 12 were used. [238] A cured film was formed using the same method as in Example 1, and then the properties of the cured film were also evaluated using the same method as in Example

1. The results thereof are given in Table 3 and Table 4 below. [239]

[240] <Example 15> [241] A photopolymer resin composition was prepared using the same method as in

Example 9, except that the alkali- soluble acrylic binder resin obtained from

Preparation Example 5 was used instead of the alkali- soluble acrylic binder resin obtained from Preparation Example 4. [242] A cured film was formed using the same method as in Example 1, and then the properties of the cured film were also evaluated using the same method as in Example

1. The results thereof are given in Table 3 and Table 4 below. [243]

[244] <Example 16> [245] A photopolymer resin composition was prepared using the same composition and method as in Example 15, except that 20 parts by weight of an alkali-soluble acrylic binder resin and 100 parts by weight of a cardo-based compound were used. [246] A cured film was formed using the same method as in Example 1, and then the properties of the cured film were also evaluated using the same method as in Example

1. The results thereof are given in Table 3 and Table 4 below. [247]

[248] <Reference Example 1> [249] A photopolymer resin composition was prepared using the same method as in

Example 9, except that the alkali- soluble acrylic binder resin obtained from

Preparation Example 6 was used instead of the alkali- soluble acrylic binder resin obtained from Preparation Example 4. [250] A cured film was formed using the same method as in Example 1, and then the properties of the cured film were also evaluated using the same method as in Example

1. The results thereof are given in Table 3 and Table 4 below. [251]

[252] <Comparative Example 1> [253] A photopolymer resin composition was prepared using the same method as in

Example 9, except that the alkali- soluble acrylic binder resin obtained from

Preparation Example 7 was used instead of the alkali- soluble acrylic binder resin obtained from Preparation Example 4. [254] A cured film was formed using the same method as in Example 1, and then the properties of the cured film were also evaluated using the same method as in Example 1. The results thereof are given in Table 3 and Table 4 below.

[Table 3]

[255] From Table 3, it can be seen that the cured film patterns formed of the photopolymer resin compositions according to embodiments of the present invention have enough optical density to exhibit a light blocking effect.

[256] Further, it can be seen that since the cured film patterns formed of the photopolymer resin compositions according to embodiments of the present invention can be compressed to a predetermined thickness when a predetermined force is applied thereto and have enough optical density to exhibit a light blocking effect, they can be usefully used to form patterns for exhibiting a light blocking effect and maintaining a cell gap.

[257] Furthermore, it can be seen that since the cured film patterns formed of the photopolymer resin compositions according to embodiments of the present invention can be thickly formed on an IZO-deposited film, they can sufficiently function as a spacer for maintaining a cell gap, and that since they have high voltage holding ratio, poor images are not displayed even when they are exposed to a liquid crystal layer, and thus they can be usefully used as a spacer for maintaining a cell gap. [Table 4 ]

[258] From Table 4, it can be seen that since the cured films formed of the photopolymer resin compositions according to embodiments of the present invention have a chemical resistance index of preferably, 97% or more, the cured films, functioning as black matrices and/or spacers for maintaining a cell gap, are not lost, and thus the photopolymer resin composition of the present invention can be usefully used to fabricate a liquid crystal display device in which black matrices and/or spacers for maintaining a cell gap are formed on a lower substrate.

[259] Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

[260]