Background A receptor film can be used to produce a marking film. An image can be formed on the front surface of a receptor film by applying a colorant such as a toner or ink, thus producing the marking film. The receptor film comprises a base layer and a receptor layer, where the receptor layer comprises a thermoplastic resin film which is provided on a surface of the base layer. In general, an adhesive layer is provided on the back surface of the receptor film to allow it to be adhered to an adherend, and the back surface of the adhesive layer is protected with a release paper or a release film.

As an image-receptor having both ink-receptivity and blocking resistance of its receptor layer, a receptor film having a receptor layer, wherein the receptor layer comprises a polyester resin with a glass transition temperature of 60°C or higher and has a coating weight of 0.8 to 2.0 g/m2 after drying, is proposed (see, e. g. JP-A-8-90941). In general, a receptor film is produced by forming an adhesive layer on the back surface of a base layer and providing a release paper on the adhesive layer to form a receptor film in the form of an elongate tape, and then the tape-form receptor film is stored in a roll form under a pressure such that the tape does not loosen. In such a case, since the receptor layer and the release paper are allowed to be in direct contact, they block each other so that a part of fibers of the release paper are transferred to the receptor layer. However, when the receptor layer disclosed in the above-mentioned patent application is used, a receptor film, which can prevent the blocking when the film is stored with laminating the receptor layer

and the release paper, and has good storage stability and also good ink transferability, can be provided, since the receptor layer has good blocking resistance.

A receptor film having a receptor layer which contains a polyester resin is also disclosed in, for example, JP-A-7-61153. The polyester resin used in that patent application has a glass transition temperature of 40°C or higher and a melting point of 150°C or lower, and is characterized in that a polyhydric alicyclic alcohol is used as the alcohol component of the polyester resin. This receptor film can be printed with a general-purpose printer or a word processor, and has good storage stability.

Although the above-described receptor film has no problem when it is printed with the general-purpose printer, the above patent application does not intend to produce a large size receptor film for a window pane, for example.

When a large size receptor film is printed, a printer using an electrostatic toner printing system (e. g. a printer produced by Synergy Computer Graphics) is often used (see e. g. JP-B-3080662). Here, the electrostatic toner printing means a printing process comprising applying static charges (for example, static charges from a stylus) to an image- forming surface, usually a dielectric material to form a latent image, and developing the latent image with suitable toners.

When electrostatic toner printing is employed, a sheet on which a toner is transferred and printed is usually a dielectric material sheet, and a typical dielectric sheet comprises a paper substrate which has inferior water resistance, UV ray resistance and weather resistance. Therefore, electrostatic toner printing whould ideally be applied instead to a substrate having good weather resistance (e. g. a polvinyl chloride base film, a polyester film, etc. ). However, no image can be formed directly on these substrates because of their mechanical or electrical properties. Thus, an image is typically electrostatically printed on a dielectric sheet and then the image formed on the dielectric sheet is transferred to a receptor film having good weather resistance. In such a case, the image is transferred from the dielectric sheet to the receptor film by placing them so that the front surface of the dielectric sheet on which the image is formed faces the front surface of the receptor layer, and then they are heated and pressed together. It is known

that the efficacy of the transfer is highly dependent on the constituents of the receptor layer. The constituents of the receptor layer should be selected to give not only good receptivity but also good adhesion between the receptor layer and the base layer and good blocking resistance, etc. Such constituents in receptor layers can include acrylate polymers, copolymers of methyl acrylate and acrylates, polyurethanes, aliphatic polyesters, etc. In general, the base layer comprises a material such as polyvinyl chloride, polypropylene, polyurethane or a paper, etc.

However, when a polyester resin is used to form a receptor layer, no receptor film is known that satisfies transferability (in particular the transferability in electrostatic toner printing) and blocking resistance at the same time.

Polyester films such as polyethylene terephthalate films are widely used in industry and have good transparency, gloss, mechanical strength, heat resistance and weather resistance. Therefore, they are candidates for use as the base layer of a receptor film.

Thus, when a polyester resin is used to form a receptor layer and the glass transition temperature of the polyester resin is suitably selected, the receptor layer can have a good affinity with and sufficient adhesion to the base layer. However, if other resins such as a copolymers of vinyl acetate and vinyl chloride are used to form a receptor layer, they have a low affinity with and poor adhesion to the base layer, so that the receptor layer can easily be peeled from the base layer. Thus, the receptor film may cause problems in use.

Accordingly, an object of the present invention is to provide a marking film which has good transferability and blocking resistance, can be used in electrostatic toner printing and has good adhesion between receptor layer and a base layer even when the base layer comprises a polyester film.

Summary The present invention provides a marking film comprising: (a) a receptor film having a front surface which is a colorant-receptive surface, and a back surface opposed to said front surface, and (b) a colorant received on said front surface of the receptor film,

wherein said receptor film comprises a receptor layer which enables the front surface to act as a colorant-receptive surface, and said receptor layer contains a resin component comprising a polyester resin the polymer chains of which comprise 55 to 70 parts by weight of a dicarboxylic acid component and 20 to 30 parts by weight of an alcohol component having a branch in a molecule.

In other aspect, the present invention provides a receptor film for use in the production of a marking film according to the present invention by electrostatic toner printing, wherein said receptor film comprises a receptor layer consisting of a thermoplastic resin film having a front surface acting as said colorant-receptive surface to which a toner is transferred, wherein said receptor layer has a glass transition temperature of 60 to 75°C.

Brief Description of the Drawings Fig. 1 is a cross-sectional view of one example of the marking film of the present invention.

Fig. 2 is a cross-sectional view of one example of the marking film of the present invention.

Detailed Description In the marking film of the present invention, the receptor layer comprises a polyester resin having polymer chains. The polymer chains of the polyester resin comprise 55 to 70 parts by weight of a dicarboxylic acid component and 20 to 30 parts by weight of an alcohol component, where the alcohol component has a branch in a molecule.

Accordingly, this provides the marking film of the present invention with excellent ink- receptivity, particularly when electrostatic toner printing is employed, and also gives good blocking resistance when the marking films are laminated and stored. Furthermore, when a polyester film is used as the base layer, the receptor layer has high affinity with and good adhesion to the polyester base layer. Thus, peeling of the receptor layer from the base layer can be efficaciously prevented.

One preferred embodiment of the marking film of the present invention will be explained by making reference to Fig. 1.

Fig. 1 schematically shows one embodiment of the marking film of the present invention. The receptor film (1) of the marking film (100) comprises a receptor layer (2) containing the polyester resin, and a base layer (3). As described above, the polymer chains of the polyester resin comprise 55 to 70 parts by weight of a dicarboxylic acid component and 20 to 30 parts by weight of an alcohol component having a branch in a molecule.

The receptor film (1) has a front surface (11) and a back surface (12), and the front surface (11) receives a colorant, that is, the toner (4). The toner (4) forms an image, which is visible from the side of the outermost surface (51) of a protective film (5) through the protective film (5).

The adhesive layer (6) is fixedly provided on the back surface (12) of the receptor film (1). Although not shown in Fig. 1, a release paper or a release film may be provided on the adhesion surface (61) of the adhesive layer (6) for protecting the adhesion surface.

The adhesive of the adhesive layer (6) is not limited, and is usually a pressure- sensitive adhesive comprising a self-adhesive polymer. As the pressure-sensitive adhesive layer, for example, a single-layer pressure-sensitive adhesive film containing a self- adhesive polymer, or a double-coated adhesive sheet having two pressure-sensitive adhesive layers is preferably used.

To adhere the protective film (5) to the receptor film (1), an adhesive layer (50) for the protective film is usually used. The adhesive of the adhesive layer (50) for the protective layer is not limited, and may be a pressure-sensitive adhesive comprising a self- adhesive polymer, since such an adhesive layer can follow the unevenness formed by the toner (4) on the surface (11) of the receptor film so that the protective film (5) and the receptor film (1) can be closely adhered to each other without bubble formation between them. Bubbles can decrease the visibility of the image, and thus it is preferable to prevent the bubbles from forming and remaining.

A further embodiment is a marking film shown in Fig. 2, which comprises the receptor film (1) having the receptor layer (2) and the base layer (3); a colorant, namely, the toner (4) received on the surface (11) of the receptor film (1) ; and the adhesive layer (6) provided on the surface of the receptor film (11). With this structure, the marking film is adhered to an adherent 7, for example a window pane or a glass pane of a door, with the adhesive layer, and thus the image formed by the toner can be seen through the base layer (3). In this case, the base layer protects the image.

The polyester resin used for the formation of the receptor layer is a resin prepared by polymerizing a monomer mixture containing a dicarboxylic acid component and an alcohol component having a branch in the molecule.

Examples of the dicarboxylic acid include phthalic acid, terephthalic acid, isophthalic acid, 2,6-naphthalene dicarboxylic acid, etc. In particular, terephthalic acid, isophthalic acid and their mixtures are preferably used.

Examples of the alcohol component having a branch in the molecule include 1,2- propylene glycol, 2,3-butanediol, etc. In particular, neopentyl glycol is preferable.

In view of the toner-receptivity and the blocking resistance, the polyester resin prepared by polymerization should comprise 55 to 70 parts by weight of the repeating units derived from the dicarboxylic acid components and 20 to 30 parts by weight of the repeating units derived from the alcohol component having a branch in a molecule.

The kinds (chemical structures) of the carboxylic acid component and the alcohol component to be used as the raw materials are suitably selected so that the glass transition temperature of the receptor layer falls in an optimum range.

The glass transition temperature of the receptor layer is usually from 10 to 90°C, preferably from 20 to 80°C, and more preferably from 60 to 70°C. When the glass transition temperature of the receptor layer is too low, tack increases at room temperature so that the laminated receptor films tend to block. When the glass transition temperature of the receptor layer is too high, the transferability of toners to the receptor layer deteriorates so that clear images may not be obtained. In addition, the receptor layer becomes brittle so that it tends to crack.

The glass transition temperature (Tg) of the receptor layer is measured by providing a film having a thickness of about 10 urn (usually 8 to 20 urn) as a sample and setting this sample on DSC (differential scanning calorimeter). In the measurement, the temperature is raised from-50°C to 120°C (first scanning), and then a glass transition temperature is read from an inflection point corresponding to a secondary transition point in the first scanning.

The molecular weight of the polyester resin to be used for the formation of the receptor layer is not limited, and the weight average molecular weight of the polyester resin is usually from 1,000 to 100,000.

The resin constituting the receptor layer (and the base layer) may contain one or more other resins as long as the effects of the present invention are not impaired.

Examples of additional resins are acrylic resins, urethane resins, etc.

The thickness of the receptor layer is usually from 2 to 50 im, preferably from 5 to 40 u. m, more preferably from 15 to 30 um. When the receptor layer is too thin, the transferability may decrease. When the receptor layer is too thick, it tends to crack or have poor adhesion to the base layer.

The material of the base layer is not limited, and is usually a polyester film such as a polyethylene terephthalate film, a polybutylene terephtalate film, etc. The polyester film can be imparted with functions necessary for a marking film for a window pane such as sunshine adjustment, scatterproof, super-scatterproof, heat insulation, insect-proof (repellency), interior viewing prevention and eyesight control.

A sunlight adjustment film means a film having effects to decrease the amount of sunlight coming into a room through a window pane. Examples of such a film are those sold under the tradename SCOTCHTINT P-18 and RE35AMARL (available from 3M Co. , St. Paul, MN), and those sold under the tradename SUNMILD (available from<BR> LINTECK Co., Ltd. ), etc.

A scatterproof film means a film having effects to prevent the scattering of broken glass. Examples of such a film are those sold under the tradename SCOTCHTINT SH2CL

(available from 3M Co. , St. Paul, MN), and those sold under the tradename LUMICOOL<BR> (available from LINTECK Co. , Ltd. ), etc.

A super-scatterproof film means a film having effects to prevent the scattering of broken glass and also high resistance to penetration and thus to increase safety. Examples of such a film are those sold under the tradename SCOTCHTINT SCLARL 400 and ULTRA 600 (available from 3M Co. St. Paul, MN), etc.

A heat insulation film means a film having effects to suppress the radiation of heat from a warmed room to outdoors and improve the indoor air-conditioning efficiency.

Examples of such a film are those sold under the tradename SCOTCHTINT WH72CLARL and LE50AMARL (available from 3M Co. St. Paul, MN), and those solde under the tradename REFTEL (available from LINTECK Co. , Ltd. ), etc.

An insect-proof film means a film having effects to shield W ray which is a cause for attracting insects and decrease the number of insects flying into a room. Examples of such a film are those sold under the tradename SCOTCHTINT IS2CLARL and RE8CLIS (available from 3M Co. , St. Paul, MN), and those sold under the tradename SUNMILD<BR> OPTRON (available from LINTECK Co. , Ltd. ), etc.

An interior viewing prevention film means a film having effects to obstruct eyes from the outdoors and make it difficult to see the interior. Examples of such a film are those sold under the tradename SCOTCHTINT RE20BRARL and RE20NEARL (available from 3M Co. , St. Paul, MN) An eyesight control film means a film having effects to control a viewable range depending on a distance and an angle from the film. Examples of such a film are those sold under the tradename LUMISTY (available from LINTECK Co. , Ltd. ), etc.

The receptor film may be prepared as follows: The polyester resin film forming the receptor layer can be prepared by a conventional film-forming method. For example, a coating liquid comprising the resin component is applied on the surface of the base layer and solidified to form the resin film.

As an application apparatus, a conventional coater such as a bar coater, a knife coater, a roll coater, a die coater, etc. may be used. The solidification includes drying in the case of

a coating liquid containing a volatile solvent, cooling of a molten resin component, when the coating liquid is a melt etc. Alternatively, the thermoplastic resin film can be formed by a melt extrusion method.

Other layers may be provided between the receptor layer and the base layer as long as the effects of the present invention are not impaired.

Then, the adhesive layer is bonded to the front or back surface of the receptor film.

To bond the adhesive layer to the back surface of the receptor film, a coating liquid containing the adhesive is applied to the back surface of the base layer and solidified to form the adhesive layer and then a liner is laminated onto the adhesive layer with the release surface of the liner applied to the back surface of the adhesive layer. Or a coating liquid containing the adhesive can be applied to the release surface of a liner and solidified to form an adhesive layer on the liner, and then the adhesive layer on the liner is laminated onto the receptor film.

The thickness of the receptor film as a whole is usually from 40 to 200 um, preferably from 60 to 150 um. When the thickness is too small, the handling of the receptor film deteriorates and the mechanical strength of the receptor film tends to decrease. When the thickness is too large, the flexibility of the receptor film may decrease so that the handling in the printing process deteriorates, and furthermore the receptor film may become expensive.

In general, the receptivity of the receptor layer to a colorant such as a toner can be evaluated as follows: First, a receptor film having a specific size is provided. Then, a digital graphic for subsequent transfer is printed onto a transfer medium (such as that available from 3M Company of St. Paul, Minnesota, USA under the trade designation TRIDENT) with an electrostatic printing system (such as the electrostatic printer available under the trade designation SCOTCHPRINT 9512 manufactured by 3M Company) using special toners.

Then, the transfer medium having the printed graphics is rolled upto obtain a roll of the printed transfer media.

Then, the above receptor film and the roll of printed transfer media are set on a laminator (such as that available under the trade designation of ORCA III available from 3M Company, St. Paul, MN), and the laminator is operated under the following conditions to transfer the toned image from the transfer media to the receptor film to obtain a roll of imaged marking film: Image transfer conditions - Temperature of the upper roll: 130°C - Temperature of the lower roll: 50°C - Web conveying speed: 80 cm/min.

-Pressure : about 410 kPa (60 psi) One hundred cross-hatch cuts (size of each section: about 1 mm x about 1 mm) are formed on the toned image, and then an adhesive tape (available under the tradename CELLOTAPE LP-24 available from NICHIBAN Co. , Ltd. ) is adhered to the toned image.

The adhesive tape is quickly peeled off. Then, whether toner is transferred to the adhesive tape is visually observed.

The adhesion of the receptor layer to the base layer can be evaluated by the same method as the evaluation of the receptivity of the receptor layer to the colorant. That is, when the adhesion is insufficient, interfacial adhesion failure occurs between the receptor layer and the base layer so that the toner and the receptor layer are transferred to the adhesive tape. Thus, the degree of transfer is observed to evaluate the adhesion of the receptor layer to the base layer.

The blocking resistance of the receptor layer is evaluated as follows: A pair of sheets, each comprising a receptor film, an adhesive layer fixedly provided on the back surface of the receptor film and a liner adhered to the adhesive surface of the adhesive layer, are provided and cut to a size of 100 mm x 150 mm, and they are laminated with the liner of one sheet in contact with the receptor layer of the other.

Then, the laminated sheets are placed in an oven at 40°C for one week under an applied load of 20 kg. Thereafter, the receptor films are separated and whether blocking has occurred is visually observed. Here, "blocking"means a state whereby a certain force is

required to separate the receptor films, the sheets are separated with the sound of rip-rip, and the surface smoothness of the receptor layer is damaged on separation.

The adhesive layer for adhering the marking film (or the receptor film) to an adherend may be formed as follows: Firstly, a liner having a release surface is provided. On the release surface of the liner, a coating liquid containing a self-adhesive polymer (an adhesive composition for forming the adhesive layer of an adhesive sheet) is applied and solidified to form an adhesive layer.

The liner is usually made of a paper sheeting or a plastic film. A paper liner is generally prepared by laminating a releasing coating (a release layer) such as a polyethylene coating, a silicone coating, etc. on the surface of the paper sheet. When a silicone release coat is laminated, usually an undercoat such as a clay coat, a polyethylene coat, etc. is laminated onto the paper sheeting before the release coat is subsequently laminated onto the undercoat.

The adhesive layer may be formed from a coating film of an adhesive comprising a self-adhesive polymer. Preferably, the adhesive contains a self-adhesive polymer and a crosslinking agent for crosslinking the polymer.

Herein, the self-adhesive polymer means a polymer having tackiness at room temperature (about 25°C). Examples of such a self-adhesive polymers include acrylic polymers, polyurethanes, polyolefins, polyesters, etc.

One example of the synthesis of an exemplary self-adhesive polymer is explained by making reference to an acrylic polymer.

As a first monomer, an acrylic unsaturated acid (e. g. acrylic acid, methacrylic acid, <BR> <BR> itaconic acid, maleic acid, etc. ) or a polar (meth) acrylic monomer (e. g. acrylonitrile, etc. ) is provided. The first monomer is mixed with an acrylic monomer as the second monomer to obtain a monomer mixture. As the second monomer, an alkyl acrylate such as isooctyl acrylate, butyl acrylate, 2-methylbutyl acrylate, 2-ethylhexyl acrylate, isononoyl acrylate, etc. may be used.

The monomer mixture is polymerized by a conventional polymerization method such as solution polymerization, emulsion polymerization, bulk polymerization, etc. to synthesize a self-adhesive polymer having a certain average molecular weight.

When a crosslinking agent is used to crosslink the self-adhesive polymer, the amount of the crosslinking agent is usually from 0.02 to 2 wt. parts, preferably from 0.03 to 1 wt. part, per 100 wt. parts of the self-adhesive polymer, although it depends on the kind of the crosslinking agent. Examples of the crosslinking agent include isocyanate compounds, melamine compounds, poly (meth) acrylate compounds, epoxy compounds, amide compounds, bisamide compounds (e. g. bisaziridine derivatives of dibasic acids such as isophthaloyl bis (2-methylaziridine), etc.).

The thickness of the adhesive layer is usually from 20 to 100 um, preferably from 25 to 80 um. The pressure-sensitive adhesive layer may contain various additives such as tackifiers, elastic microspheres, microspheres of tacky polymers, crystalline polymers, inorganic powders, UV-ray absorbers, etc.

The protective film has light transmission properties as a whole. The light transmittance of the protective film is usually at least 60 %, preferably at least 70 %, and more preferably at least 80 %. Here, the light transmittance is a total light transmittance measured with a spectrophotometer or a colorimeter which functions also as a photometer at a wavelength of 550 nm.

If desired, the protective film may be imparted with one or more functions necessary for a marking film for a window pane such as sunshine adjustment, scatterproof, super- scatterproof, heat insulation, insect-proof (repellency), interior viewing prevention and eyesight control. As films having such functions, the films described in connection with the base layer can be used.

The protective film preferably comprises a resin film containing a resin with high transparency. Examples of such a resin include fluoropolymers, phthalate-based polyesters (e. g. PET, PEN, etc. ), acrylic resins, etc. Fluoropolymers are polymers obtained by polymerizing at least one fluorine-containing monomer. Examples of the fluorine-containing monomers include fluorine-containing ethylene monomers such as

vinylidene fluoride, hexafluoropropylenes, tetrafluoroethylene, trifluorochloroethylene, etc.

In addition, one or more monomers copolymerizable with the fluorine-containing monomer such as a methacrylate monomers (e. g. methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, etc. ) and acrylate monomers (e. g. methyl acrylate,<BR> ethyl acrylate, propyl acrylate, butyl acrylate, etc. ) may be mixed with the fluorine- containing monomer (s).

Furthermore, the protective film may be made of a resin composition comprising the fluororesin and an acrylic resin.

The thickness of the protective layer is usually from 10 to 300 um, preferably from 20 to 150 pm. When an adhesive layer is used to adhere the protective film to the receptor film, it usually has a thickness of 10 to 100 um, and preferably has a thickness of 20 to 50 urn.

The colorant is usually a toner or an ink. A conventional printing method can be used to print the toner onto the front surface of the receptor layer. When an electrostatic toner printing method is used, an image is printed onto a temporary support (transfer medium) and then the image is transferred to the receptor layer. In such a transfer method, the image is firstly formed on the temporary support, which may be called a transfer medium, and then transferred to the front surface of the receptor film with heating and pressure to obtain a receptor layer having the printed image.

The toner used to form the image contains a binder resin and a pigment dispersed in the binder resin. The binder resin may be a resin selected from the group consisting of acrylic resins and polyester resins and a mixture thereof.

The details of the electrostatic printing method are disclosed in JP-A-4-216562, JP- A-11-513818, etc.

Examples Example 1 A receptor film in this Example was produced as follows:

Terephthalic acid, isophthalic acid, neopentyl glycol and propylene glycol were copolymerized in a weight ratio of 34: 33: 22: 11 to obtain a polyester having a glass transition temperature of 68°C and a molecular weight of about 18,000. This resin was diluted with a mixed solvent of toluene and MEK (methyl ethyl ketone) (volume ratio of 1: 1) to adjust the solid content to 25 % by weight. The resulting resin solution was applied with a knife coater onto the surface of a polyester film having functionality to prevent glass scattering (available under the tradename SCOTCHTINT SH2CLXL from 3M Company, St. Paul, MN) and dried at 65°C for 2 minutes and then at 105°C for 2 minutes to form a receptor layer having a dry coating weight of 25 g/m2 and a dry coating thickness of 20 am.

The polyester film has a pressure-sensitive adhesive layer on the back surface of polyester base layer, and a liner which protects the back surface of the adhesive layer.

Therefore, the receptor layer was formed on the surface of the base opposite to the adhesive layer. Thereby, a receptor film, which comprised the polyester film having a function to prevent glass scattering as the base layer and had the receptor layer on the surface of the base layer, the adhesive layer on the back surface of the base layer and further the liner on the back surface of the adhesive layer, was obtained.

Using the receptor film obtained in the previous step, a marking film of this Example was produced as follows: Digitally-printed graphics for transfer were formed with special toners on a transfer medium (commercisally available under the trade designation of TRIDENT from 3M Company, St. Paul, MN) by means of an electrostatic printing system (electrostatic printer available under the trade designation of SCOTCHPRINT 9512 available from 3M Company, St. Paul, MN). Then, the transfer medium having the printed graphics was rolled up to obtain a roll of digitally-printed transfer medium.

Then, the above receptor film and the above roll of printed transfer medium were set on a laminator (available from 3M Company, St. Paul, MN under the trade designation of ORCA III), and the laminator was operated under the following conditions, and the

toned image was transferred to the receptor film to obtain a roll of the marking film of this Example: Image-transferring conditions - Temperature of laminator upper roll: 130°C - Temperature of a laminator lower roll: 50°C - Web conveying speed: 80 cm/min.

-Pressure : about 410 kPa (60 psi) The receptivity of the receptor layer to the toners and the adhesion of the receptor layer to the base layer were evaluated by the evaluation methods described above. No transfer of the toners or the receptor layer to the adhesive tape was observed. Thus, it was confirmed that the toner-receptivity and the adhesion of the receptor layer were good.

The blocking resistance of the receptor layer was evaluated. No blocking occurred.

Separately, a transparent protective film was adhered to the toner image on the marking film (the colorant-receptive surface) with an adhesive to obtain a marking film with a protective film. The protective film used was a polyester film having a function to prevent glass scattering (available under the trade designation of SCOTCHTINT SH2CLXL from 3M Company, St. Paul, MN) Comparative Example 1 The receptor film of this Comparative Example was produced in the same manner as in Example 1 except that the receptor layer was formed from a vinyl chloride/vinyl acetate copolymer resin. The thickness of the receptor layer was 20 u. m.

The toner-receptivity, adhesion and blocking resistance of the receptor layer were evaluated in the same manner as in Example 1. The adhesion of the receptor to the base layer was poor, and thus the receptor layer and the toners were transferred to the adhesive tape used in the evaluation. However, no blocking occurred.

Comparative Example 2 The receptor film of this Comparative Example was produced in the same manner as in Example 1 except that the receptor layer was formed from a polyester resin which was produced by copolymerizing terephthalic acid, isophthalic acid, neopentyl glycol and

ethylene glycol in a weight ratio of 25: 24: 25: 26. The receptor layer had a thickness of 20 um, a glass transition temperature of 67°C and a molecular weight of about 17,000.

The toner-receptivity, adhesion and blocking resistance of the receptor layer were evaluated in the same manner as in Example 1. Blocking occurred.

Comparative Example 3 The receptor film of this Comparative Example was produced in the same manner as in Example 1 except that the receptor layer was formed from a polyester resin which was produced by copolymerizing terephthalic acid, isophthalic acid, ethylene glycol and propylene glycol in a weight ratio of 51: 18: 8: 23. The receptor layer had a thickness of 20 um, a glass transition temperature of 79°C and a molecular weight of about 18,000.

The toner-receptivity, adhesion and blocking resistance of the receptor layer were evaluated in the same manner as in Example 1. The adhesion of the receptor to the base layer was poor (low), and thus the receptor layer and the toners were transferred to the adhesive tape used in the evaluation. However, no blocking occurred.

Comparative Example 4 The receptor film of this Comparative Example was produced in the same manner as in Example 1 except that the receptor layer was formed from a polyester resin which was produced by copolymerizing terephthalic acid, isophthalic acid, neopentyl glycol and propylene glycol in a weight ratio of 25: 24: 27: 24. The receptor layer had a thickness of 20 um, a glass transition temperature of 67°C and a molecular weight of about 23,000.

The toner-receptivity, adhesion and blocking resistance of the receptor layer were evaluated in the same manner as in Example 1. Blocking occurred.

Comparative Example 4 The receptor film of this Comparative Example was produced in the same manner as in Example 1 except that the receptor layer was formed from a polyester resin which was produced by copolymerizing terephthalic acid, ethylene glycol and propylene glycol in a weight ratio of 67: 7: 26. The receptor layer had a thickness of 20 um, a glass transition temperature of 77°C and a molecular weight of about 8,000.

The toner-receptivity, adhesion and blocking resistance of the receptor layer were evaluated in the same manner as in Example 1. The adhesion of the receptor to the base layer was low, and thus the receptor layer and the toners were transferred to the adhesive tape used in the evaluation. However, no blocking occurred.