JPH06127162A - Image receiving sheet for thermal transfer - Google Patents

Abstract

PURPOSE:To provide a thermal transfer image receiving sheet imparting high transfer density and high glass and generating no image blur. CONSTITUTION:A thermal transfer image receiving sheet is constituted of a support formed by bonding a synthetic resin film having a porous structure to at least the single surface of a core material and providing a heat-resistant surface layer composed of a radiation curable resin on the surface film and the image receiving layer provided to the heat-resistant surface layer of the support.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image-receiving sheet for thermal transfer which is excellent in transfer density, has high gloss, and has no image bleeding.

[0002]

2. Description of the Related Art In recent years, a thermal transfer recording system has been widely used as a means of color hard copy because of its advantages such as light weight, compact size, no noise, excellent operability and maintainability. is doing. This thermal transfer recording system is roughly classified into two types, which are a heat melting type and a heat transfer type or a sublimation type. In particular, the latter is excellent in reproducibility of multicolor gradation images and is printed by using a sublimation type thermal transfer type printer. The principle of such a sublimation type thermal transfer type printer is that a sheet in which an image is converted into an electric signal and the electric signal is further converted into a heat signal by a thermal head and a heat transfer dye is applied (ink donor sheet). Information is recorded by transferring the dye from the ink donor sheet to the image-receiving layer of the thermal transfer image-receiving sheet by heating and by sublimation or diffusion in the medium. In particular, in recent years, it has been required to improve the transfer density from the viewpoint of increasing the printing speed, and for such high sensitivity, it is effective that a synthetic resin film having a porous structure having excellent heat insulating properties and cushioning properties is effective. For example, it is described in JP-A-63-231984.

[0003]

However, such synthetic resin films are generally formed of polyethylene, polypropylene, polyethylene terephthalate, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, ethylene-
Since it is composed of materials with poor heat resistance such as vinyl acetate copolymer and ethylene-vinyl alcohol copolymer, the heat shrinks during printing, causing the support to shrink, resulting in a lack of image dot reproducibility. Not only that, but when the film having a porous structure is finished for the purpose of improving the heat insulating property and the cushioning property in particular for improving the sensitivity, the smoothness of the surface is deteriorated, so that the glossiness is decreased. , Causing a significant decrease in product quality. In particular, for high-quality color images, silver halide photography is now widely used and its high gloss has been required in the field of thermal transfer image-receiving sheets, but with the conventional technology, high gloss is required to obtain high transfer density. It was difficult to achieve both high sensitivity and high gloss.

[0004]

On the other hand, a synthetic resin film having a porous structure is attached to at least one surface of a core material made of cellulose fiber paper or synthetic resin film,
An image-receiving sheet for thermal transfer comprising a support having a heat-resistant surface layer made of a radiation-curable resin on the non-adhesive side, and an image-receiving layer provided on the heat-resistant surface layer of the support. It was possible to obtain an image-receiving sheet for thermal transfer having a high transfer density and a high gloss.

The present invention will be described in detail below. Examples of the core material used in the present invention include cellulose fiber paper and synthetic resin film, and those obtained by laminating the above-mentioned cellulose fiber paper and synthetic resin film can also be used. Examples of the cellulose fiber paper include high-quality paper, coated paper, art paper, synthetic resin or emulsion-impregnated paper, etc., and synthetic resin films such as polyolefin, polyvinyl chloride, polyethylene terephthalate, polystyrene, and polycarbonate are generally used in general. Whether the formed film is porous or non-porous, it can be appropriately used depending on the purpose. Further, the above cellulose fiber paper obtained by extrusion coating a polyolefin or the like can also be used. The thickness of the core material is preferably 50μ to 500μ.

On the other hand, as a synthetic resin film having a porous structure to be used by sticking to the above core material, polyethylene, polypropylene, polyethylene terephthalate, polyvinyl chloride, polyvinylidene chloride,
Synthetic resin films such as polyvinyl alcohol, ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer polyethylene, and polyamide can be mentioned. Especially for the purpose of increasing sensitivity, the density of non-porous film of the same material is 85%. The following are preferred. Although the density of a normal non-porous film varies depending on the material, for example, polyolefin such as polyethylene and polypropylene is about 1.0 to 0.9, and polyester is about 1.4.
As in the present invention, by using a synthetic resin film having a porous structure having a density of 85% or less of that density, it is possible to print with high density even with a low thermal energy. The thickness of the film is preferably about 40 to 200 μm. To give a specific example, in the case of a polyester film, a diamond foil W900 manufactured by Diafoil Co., Ltd. (foamed white polyester film, the density is about 1.0, the density of the non-porous polyester film is about 1.4 to 71). %), For polypropylene, Yupo FPG from Oji Yuka Synthetic Paper Co., Ltd. (density is about 0.77, 85% of non-porous polypropylene film) and Toyobo of Toyobo (density is about 0.6. 66% of porous polypropylene film) and the like.

The core material and the synthetic resin film having a porous structure may be provided on only one side or on both sides of the core material. As a sticking method, for example, sticking using a conventionally known adhesive,
Examples of the method include sticking using the extrusion lamination method and sticking by heat bonding. As a concrete example of the above adhesive,
Examples thereof include emulsion adhesives such as ethylene-vinyl acetate copolymer and polyvinyl acetate, and water-soluble adhesives such as carboxyl group-containing polyester. As the adhesive for lamination, an organic solvent-based adhesive such as polyurethane or acrylic can be used. Furthermore, if necessary, a thermosetting or photocurable resin or the like can be used.

However, a film having a porous structure generally has low smoothness and low gloss due to its structure. For example, in the above example, the diamond foil W900 has 15
No. 30 to 30, Yupo FPG 14 to 16 and Toyopearl had the same degree (60 degree gloss in each case), which was far below the gloss degree of about 80 to 90 of silver salt color photographs.

On the other hand, when a heat resistant surface layer made of a radiation curable resin is provided on a film having a porous structure,
It was possible to obtain a support having excellent heat resistance and high gloss. A suitable thickness is about 1 μ to 25 μ, and when it is 1 μ or less, high glossiness cannot be expected because it is applied on a film having a porous structure with originally low smoothness, and when the thickness is 25 μ or more. However, the heat insulating property and cushioning property of the porous structure of the film under the radiation curable resin cannot be effectively utilized, and the transfer density is lowered. As a method of applying a heat resistant surface layer made of a radiation curable resin on a synthetic resin film having a porous structure, for example, blade coat, air doctor coat, squeeze coat, air knife coat, reverse roll coat, gravure roll and Methods such as transfer roll coating, bar coating and curtain coating are used. Also, if necessary, a heat-resistant surface layer made of a radiation curable resin is provided between the synthetic resin film having a porous structure and the highly smooth film, and after being cured by irradiation with radiation while still having plasticity, You may peel a high smoothness film and manufacture a support body. In addition, a metal roll having a high smoothness is used instead of the high smoothness film, and a layer made of a radiation curable resin is provided between the synthetic resin film having a porous structure and the metal roll so as to have flexibility. It is also possible to irradiate the surface with radiation to form a highly smooth surface.

An object of the present invention is to provide a highly smooth heat resistant surface layer made of a radiation curable resin on a synthetic resin film having a porous structure which is adhered to a core material.
An object of the present invention is to provide a thermal transfer image-receiving sheet having excellent transfer density and high gloss.
As described in Japanese Patent Publication No. 4 etc., a thermoplastic resin layer is provided as an intermediate layer between a synthetic resin film having a porous structure and an image receiving layer, and its cushioning property is not intended to increase print density, but rather. The purpose of the present invention is to form a highly smooth surface layer excellent in heat resistance that does not show thermoplasticity by three-dimensionally crosslinking by radiation and to achieve both high sensitivity and high gloss by making it an image-receiving sheet for thermal transfer. There is.

The ionizing radiation for curing the radiation-curable resin composition is generally ultraviolet rays, α rays, β rays, γ rays,
Examples include X-rays, electron beams, etc., but α-rays, β-rays, γ-rays, and X-rays are easy to handle and are widely used industrially because they pose a problem of danger to the human body. Effective ultraviolet rays and electron beams.

When an electron beam is used, it is desirable to adjust the amount of the electron beam to be irradiated within the range of 0.1 to 10 Mrad. If it is 0.1 Mrad or less, a sufficient irradiation effect cannot be obtained, and if it is 10 Mrad or more, the film substrate is deteriorated, which is not preferable. As an electron beam irradiation method,
A scanning method, a curtain beam method, etc. are adopted,
The acceleration voltage for irradiating the electron beam is preferably about 100 to 300 KV.

When ultraviolet rays are used, it is necessary to add a sensitizer to the radiation curable resin composition.
Specific examples thereof include acetophenones such as di- or trichloroacetophenone, benzophenone, Michler's ketone, benzyl, benzoin, benzoin alkyl ether, benzyl dimethyl ketal, tetramethyl thiuram monosulfide, thioxanthones, azo compounds, etc., and radiation curing It is selected from the viewpoints of the type of polymerization reaction, stability of the radiation-curable resin and the radiation-curable silicone resin, and compatibility with a radiation irradiation device. The amount of the photosensitizer used is usually in the range of 1 to 5% with respect to the radiation curable resin or the radiation curable silicone resin.
In addition, a storage stabilizer such as hydroquinone may be used in combination with the photosensitizer. As the light source, for example, a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, a xenon lamp, a tungsten lamp, etc. are preferably used.

The high glossiness of the image-receiving sheet for thermal transfer of the present invention is derived from the material of the radiation-curable resin, but by improving the smoothness of the heat-resistant surface layer, a higher glossiness can be obtained. Can be done. It is preferable that the heat-resistant surface layer provided on the synthetic resin film having this porous structure has a high smoothness, and the surface roughness is 1. As the center line average roughness (Ra).
The material is not particularly limited as long as it is 0 μ or less, preferably 0.5 μ or less.

The radiation-curable resin used in the heat-resistant surface layer of the present invention is a compound having a reactive group such as an acryloyl group, a methacryloyl group, or an epoxy group at a molecular end or a molecular side chain, and is an unsaturated polyester. , Modified unsaturated polyester, acrylic polymer, acrylic monomer, methacrylic polymer, methacrylic monomer and monomer or oligomer having vinyl type unsaturated bond, epoxy compound and the like can be used alone or together with other solvents. Hereinafter, representative ones will be exemplified.

(A) Polyester acrylate, polyester methacrylate; for example, Aronix M-53
00, Aronix M-5400, Aronix M-5
500, Aronix M-5600, Aronix M-
5700, Aronix M-6100, Aronix M
-6200, Aronix M-6300, Aronix M-6500, Aronix M-7100, Aronix M-8030, Aronix M-8060, Aronix M-8100 (above, Toa Gosei Chemical Industry Co., Ltd. trade name), Viscoat 700, Viscoat 3700 (above,
Product name of Osaka Organic Chemical Industry Co., Ltd., Kayarad HX-2
20, Kayarad HX-620 (Nippon Kayaku Co., Ltd.)
Product name)

(B) Epoxy acrylate, epoxy methacrylate; for example, NK ester, EA-800,
NK Ester, EPM-800 (above, trade name of Shin-Nakamura Chemical Co., Ltd.), Viscoat 600, Viscoat 540
(Above, product name of Osaka Organic Chemical Industry Co., Ltd.), Photomer 3016, Photomer 3082 (above, product name of San Nopco Co., Ltd.)

(C) Urethane acrylate, urethane methacrylate; for example, Aronix M-1100, Aronix M-1200, Aronix M-1210,
Aronix M-1250, Aronix M-126
0, Aronix M-1300, Aronix M-13
10 (above, trade name of Toagosei Chemical Industry Co., Ltd.), viscoat 812, viscoat 823, viscoat 823 (above, trade name of Osaka Organic Chemical Industry Co., Ltd.), NK ester,
U-108-A, NK ester, U-4HA (above, Shin Nakamura Chemical Co., Ltd. trade name)

(D) Monofunctional acrylate, monofunctional methacrylate; for example, methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, tetrahydrofuran. Furyl acrylate, phenoxyethyl acrylate, cyclohexyl acrylate, cyclohexyl methacrylate, benzyl acrylate, glycidyl methacrylate, N, N-dimethylaminoethyl acrylate, N, N-dimethylaminoethyl methacrylate, N, N-diethylaminoethyl methacrylate, butoxyethyl acrylate and the like. Ethylene oxide-modified phenoxyphosphoric acid acrylate Ethylene oxide-modified butoxylated phosphoric acid acrylate, and other trade names of Toagosei Kagaku Kogyo Co., Ltd. are Aronix M-101, Aronix M-102, Aronix M-111, Aronix M-113. , Aronix M-114, Aronix M-117, Aronix M-152, Aronix M-154 and the like.

(E) Polyfunctional acrylate, polyfunctional methacrylate; for example, 1,6-hexanediol diacrylate, 1,6-hexanediol dimethacrylate, neopentyl glycol diacrylate, diethylene glycol diacrylate, polyethylene glycol diacrylate, polyethylene. Glycol dimethacrylate, polypropylene glycol diacrylate, polypropylene glycol dimethacrylate, pentaerythritol diacrylate, dipentaerythritol hexaacrylate, isocyanuric acid diacrylate, pentaerythritol triacrylate, isocyanuric acid triacrylate, trimethylolpropane triacrylate, trimethylolpropane triacrylate Methacrylate, ethylene oxide modified polyethylene Examples thereof include ethylene erythritol tetraacrylate, propylene oxide-modified pentaerythritol tetraacrylate, propylene oxide-modified dipentaerythritol polyacrylate, and ethylene oxide-modified dipentaerythritol polyacrylate. The product names of Toagosei Kagaku Kogyo Co., Ltd. are Aronix M-210, Aronix M-215, Aronix M-220, Aronix M-230, Aronix M-233, Aronix M-240, Aronix M-245, Aronix M. -305, Aronix M-309, Aronix M-310, Aronix M
-315, Aronix M-320, Aronix M-
325, Aronix M-330, Aronix M-4
00, TO-458, TO-747, TO-755, T
HIC. TA2 etc. are mentioned.

(F) Epoxy compound; for example, glycidyl methacrylate, 1,3-bis (N, N-diepoxypropylaminomethyl) cyclohexane, 1,3-bis (N, N-diepoxypropylaminomethyl) benzene and the like can be mentioned. .
The product name of Mitsubishi Gas Chemical Co., Ltd. is GE-510,
Examples include TETRAD-X and TETRAD-C.

However, even if a radiation curable resin is used,
If the curing by radiation is insufficient, the image-receiving layer after dye transfer provided thereon may gradually penetrate into the radiation-curable resin layer to cause image bleeding, probably because it exhibits thermoplasticity. To prevent this bleeding, it is necessary to strengthen the radiation energy. However, depending on the support, the strength may be deteriorated, and it has become clear as a result of the study by the present inventors that a resin having essentially high radiation curing reactivity is preferable for image bleeding.

From this point of view, it was found that a compound containing an acryloyl group in the molecule, and the compound having an acryloyl equivalent of 190 or less, can be particularly preferably used for the purpose of the present invention. . The acryloyl equivalent is a numerical value obtained by dividing the molecular weight by the number of acryloyl groups in the molecule, and the smaller the numerical value, the higher the density of the photocrosslinking functional group.

Typical examples of the resin that can be used in the present invention are Aronix series manufactured by Toa Gosei Chemical Industry Co., Ltd.
I will give you an example with the product name and acryloyl equivalent in
The present invention is not limited to this. The value in () indicates acryloyl equivalent. M-7100 (188.
7), M-8030 (119.1), M-8060 (1
36.1), M-150 (111.0), M-220
(141.0), M-230 (153.8), M-24.
0 (142.0), M-305 (99.3), M-30
9 (98.7), M-310 (156.7), M-31.
5 (141.0), M-400 (96.3), M-56.
00 (165.6), M-325 (179.9), M-
8100 (155.0), M-9050 (181.4)

Coloring pigments, white pigments and the like can be used in the heat-resistant surface layer of the present invention if necessary. Specific examples of the white pigment include barium sulfate and titanium dioxide (rutile type and anatase). Type), zinc sulfide, calcium carbonate, magnesium oxide, various silicates, aluminum oxide, titanium phosphate, satin white, talc, clay and the like. Particularly, from the viewpoint of high whiteness, barium sulfate, titanium dioxide, calcium carbonate and the like are preferably used. When the content of the white pigment is less than 15% by weight, the whiteness is unsatisfactory, and when it is more than 50% by weight, the liquidity of the coating solution is poor and a uniform and highly smooth surface is obtained. As a result, the image quality is deteriorated, and the layer becomes brittle, so that stress cracks and cracks are likely to occur. In addition, an antistatic agent, a fluorescent whitening agent and the like may be added to the heat resistant surface layer, if necessary. Various kneaders can be used for kneading and dispersing the coating composition. For example, two kneaders
A rumill, a triple roll mill, a ball mill, a sand clinker, a high speed stone mill, a kneader, a homogenizer and the like are useful. The coating may be carried out in a solvent-free system, or may be dissolved or dispersed in water or an organic solvent to remove the solvent after coating and then be radiation-cured.

On the support of the present invention, a thermal transfer image-receiving sheet is constructed by providing an image-receiving layer having a dyeing property to a dye which is melted or sublimated by heat and migrates. The dye constituting the image-receiving layer is provided. As the dyeable binder resin, any resin that has a strong interaction with the dye and can stably diffuse the dye into the resin can be preferably used. For example, one having an ester bond Examples of the polyester resin, polyacrylic acid ester resin, polycarbonate resin, polyvinyl acetate resin, styrene acrylate resin and the like; and those having a urethane bond, a polyurethane resin; those having an amide bond As a polyamide resin (nylon); as a resin having a urea bond, a urea resin; and as a resin having another bond of high polarity, polycaprolactone Fat, polystyrene resins, polyvinyl chloride, polyacrylonitrile resins, etc. can be used, or,
It can also be used as a copolymer containing at least one of the above structural units of the resin as a main component, for example, vinyl chloride-vinyl acetate copolymer, styrene-butadiene copolymer, and the like.
Further, the above resins can be used alone or in combination of two or more kinds. The above resin may be dissolved in water or an organic solvent and applied on the heat resistant surface layer, or may be emulsified in an aqueous solution and applied as an emulsion, but if necessary, it may be applied on the heat resistant surface layer. It is also possible to improve the adhesion with the image receiving layer by subjecting it to an easy-adhesion treatment. As a method for making the heat-resistant surface layer easily adhesive, a method of modifying the surface of the heat-resistant surface layer by corona treatment, plasma treatment, or the like, or applying a resin having good adhesiveness to both the heat-resistant surface layer and the image receiving layer There is something to do. As such a resin, any resin having good adhesiveness to both layers can be preferably used, but for example, an acrylic resin, a vinyl chloride resin, a vinyl acetate resin, a urethane resin,
Examples thereof include styrene-butadiene-based resins and copolymers thereof. The resin used in the above image-receiving layer generally forms a nearly transparent film after drying, and does not reduce the white gloss of the thermal transfer image-receiving sheet, but significantly reduces the high gloss of the support surface. The coating amount is 0.5 to 10.0 g / m as dry solid content in the range not allowed.
^It can be appropriately set within the range of ² .

In the present invention, the release agent added to the image-receiving layer is used for the purpose of preventing blocking. Specific examples include waxes such as higher fatty acids or esters thereof, amides or metal salts thereof, shellac wax, montan wax, carnauba wax, polyethylene wax and Teflon powder; fluorine-based and phosphoric acid ester-based surfactants; Silicone oil and the like can be mentioned. As the silicone oil, amino-modified silicone, epoxy-modified silicone, alkyd-modified silicone, polyester-modified silicone and other modified silicone oil are also used, but the surface of the image-receiving sheet has a high gloss. In terms of maintaining the temperature, it is desirable that the solvent is not present in a dispersed state but is applied in a solvent-soluble state and is present in a transparent state. Further, as the silicon compound, a hardening type silicon compound can be used if necessary. As the curable silicon compound, a reaction curable type, an ionizing radiation curable type,
A catalyst hardening type etc. are mentioned.

Further, if necessary, dyes, pigments, wetting agents,
The image receiving layer may contain additives such as a defoaming agent, a dispersant, an antistatic agent, a fluorescent brightening agent, an ultraviolet absorber and a light stabilizer. In particular, with regard to pigments, high-gloss support can be obtained by allowing inorganic particles typified by silica, alumina, titanium oxide, calcium carbonate, kaolin, clay, zinc oxide and barium sulfate to exist in the image receiving layer in the form of fine particles. An image-receiving sheet for thermal transfer can be formed without reducing the glossiness of.
The particle size of the inorganic fine particles is preferably 1 μm or less.

In addition, a back surface layer to which inorganic fine powder is added is provided on the back surface on the side opposite to the image receiving layer with respect to the support in order to impart slipperiness with a roll at the time of transfer and writability to the back surface layer after transfer. It may be provided or an antistatic agent may be contained in the back surface layer for the purpose of antistatic. When the core material and the synthetic resin film having a porous structure are attached on one side, the back surface layer is directly provided on the core material, or the film having the porous structure is attached on both sides of the core material. In this case, a back layer can be further provided as the lower layer. When an adhesive resin is mixed in the back surface layer, it is also possible to mix the adhesive resin and an antistatic agent to cause bleeding on the surface of the resin layer, and consequently to provide it on the resin layer. As the antistatic agent, a surfactant,
Examples thereof include cationic surfactants (quaternary animonium salts, polyamine derivatives, etc.), anionic surfactants (alkyl phosphates, etc.), zwitterionic surfactants or nonionic surfactants.

[0030]

The present invention provides a support comprising a core material and a porous synthetic resin film attached to at least one surface thereof, and a heat-resistant surface layer made of a radiation curable resin provided on the film surface. A thermal transfer image-receiving sheet in which an image-receiving layer is provided on the heat-resistant surface layer of a support, and an excellent high-sensitivity and high-gloss thermal transfer image-receiving sheet can be obtained. Further, if necessary, an acryloyl equivalent is 190 or less. By using the above radiation-curable resin, it was possible to obtain an image-receiving sheet for thermal transfer without causing image bleeding even with low irradiation energy.

[0031]

The present invention will be described in detail below with reference to examples, but the contents of the present invention are not limited to the examples. In addition, "part" in an Example is a weight part. The ink donor sheet for evaluation was prepared as follows. Kaya Set Bull-906 (manufactured by Nippon Kayaku, sublimation dye) 10 parts Ethyl semeroses 10 parts Syloid 244 (Fuji Devison silica gel) 10 parts Isopropyl alcohol 30 parts A sublimation dye solution in a ball mill for 2 days. After crushing, a wire bar was applied on the heat-resistant polyester film to obtain about 1.
5 g / m ^{2 was} applied to make a donor sheet.

Example 1 A diamond foil W900 # 50 (foamed white polyester film, density 1.0, thickness 50 μ) was coated with an organic solvent solution of a polyurethane resin-polyisocyanate adhesive (coating amount when dry: 8 g / m ² ), dried, and a double-sided coated paper (basis weight 105 g / m ² ) was attached to the surface. Further, after the above synthetic resin film was similarly adhered to the opposite surface of the uncoated paper, a heat resistant surface layer having the following composition was kneaded and dispersed with a triple roll mill to obtain 10 μm. Then, the heat-resistant surface layer was cured by applying it onto the synthetic resin film and irradiating it with an electron beam (accelerating voltage: 200 KV, irradiation dose 3.0 Mrad). (Heat-resistant surface layer formulation) () is acryloyl equivalent. Aronix M-400 (96.3) 75 parts by weight Titanium dioxide 25 parts by weight A polyester resin emulsion (Vylonal MD-1200: by air knife coater) on the above heat-resistant surface layer.
Toyobo) and silica as an inorganic fine particle (Aerosil 20)
0: Nippon Aerosil) with a dry solid content of 2.5 g / m2 each
² and 0.3 g / m ² were applied and dried to obtain a thermal transfer image-receiving sheet.

Example 2 YUPO FPG # 80 (polypropylene film containing fine bubbles, density 0.77, thickness 80 μ) and laminated paper (basis weight 120 g / m 2) were dry-laminated using a urethane adhesive, and then YUPO Aronix M-7 on FPG
100 (188.7) was diluted with an organic solvent and applied to a support, and after removing the solvent, electron beam irradiation (acceleration voltage: 150 KV,
A heat-resistant surface layer was provided so that the irradiation dose was 2.0 Mrad and the thickness was 5 μm, to obtain an image-receiving sheet for thermal transfer. Polyester resin (Vylon 200: Toyobo) and alkyd-modified silicon dissolved in an organic solvent on the heat-resistant surface layer so that the dry solids are 2.5 g / m ² and 0.3 g / m ² , respectively. After coating and drying, an image receiving sheet for thermal transfer was obtained.

Example 3 Toyopearl (a porous polypropylene film manufactured by Toyobo,
A density of 0.6 and a thickness of 50 μ) are coated with an organic solvent solution of polyurethane resin (coating amount when dry 9 g / m ² ), dried, and cast coated paper (basis weight 105 g / m ² ) on the surface.
Was attached. Furthermore, after the above synthetic resin film was similarly adhered to the opposite surface of the uncoated cast coated paper, a heat resistant surface layer having the following composition was applied onto Toyopearl at 15 μm using a gravure offset coater. And a high-smoothness polyester film is adhered to the coated surface and cured by electron beam irradiation (accelerating voltage: 200 KV, irradiation dose 2.5 Mrad), the polyester film is peeled off, and then air-knife coater is applied. -A polyester resin emulsion (Vylonal MD-1200: Toyobo) and colloidal silica (Snowtex O: Nissan Kagaku) as inorganic fine particles having a dry solid content of 3.0 g /
An image-receiving sheet for thermal transfer was obtained by coating and drying so as to have m ² and 0.5 g / m ² . (Heat-resistant surface layer composition) Aronix M-8030 (119.1) 85 parts by weight Titanium dioxide 15 parts by weight

Comparative Example 1 Air was directly applied onto a support prepared in the same manner as in Example 1.
Using a knife coater, polyester resin emulsion (Vylonal MD-1200: Toyobo) and silica (Aerosil 200: Nippon Aerosil) were added to dry solids of 2.
An image-receiving sheet for thermal transfer was obtained by coating and drying so as to be 5 g / m ² and 0.3 g / m ² .

Comparative Example 2 In the same manner as in Example 2, except that Diafoil G100 (non-porous polyester film, density 1.4) was used in place of YUPO FPG # 80 when the support of Example 2 was prepared. After the support was prepared, a heat-resistant surface layer having the following composition was kneaded and dispersed with a triple roll mill, coated so as to have a particle size of 10 μm, and irradiated with an electron beam (accelerating voltage: 200 KV, irradiation dose: 3.
The heat resistant surface layer was cured at 0 Mrad). (Heat-resistant surface layer formulation) () is acryloyl equivalent. Aronix M-6400 (1050) 95 parts by weight Titanium dioxide 5 parts by weight Polyester resin emulsion (Vylonal MD-1200: Toyobo) and colloidal silica (Snowtex O: on the above intermediate layer with an air knife coater). Nissan Chemical Co., Ltd. has a dry solid content of 2.5 g / m ² and 0.3 g / m ^{2 respectively.}
To obtain a thermal transfer image-receiving sheet.

Comparative Example 3 A support was prepared in the same manner as in Example 3, and then the following composition having the following composition was applied as a heat resistant surface layer composition using a gravure offset coater to a thickness of 15 μm. After doing
Stick a high smoothness polyester film on the coated surface,
Electron beam irradiation (accelerating voltage: 200KV, irradiation dose 2.5M
After curing with rad), the polyester film is peeled off, and then titanium oxide (average particle size 3 μ) is dispersed on the above heat-resistant surface layer in a polyester resin (Vylon 200: Toyobo) dissolved in an organic solvent. The resulting image-receiving layer was coated and dried so that the dry solids were 2.5 g / m ² and 0.3 g / m ² , respectively, to obtain an image-receiving sheet for thermal transfer. (Heat resistant surface layer composition) Aronix M-6250 (225.0) 85 parts by weight Titanium dioxide 15 parts by weight

Comparative Example 4 A support was prepared in the same manner as in Example 3, and then a urethane primer was applied as an intermediate layer thereon to a thickness of 10 .mu.m, and then a polyester resin emulsion (byronal) was applied with an air knife coater. MD-1200: manufactured by Toyobo) and the coating of titanium oxide (average particle size 3.mu.) as dry solids is each 3.0 g / m ² and 0.5 g / m ^2, and dried to give a thermal transfer image receiving sheet It was

An ink donor sheet was placed on the image-receiving sheet for thermal transfer thus obtained so as to face it, and S3600 manufactured by Mitsubishi Electric Corporation was used.
It was printed at -30. The obtained transfer density was measured and evaluated with a Macbeth densitometer. Further, the glossiness (white paper portion) of the image receiving sheet was evaluated by 60 degree glossiness. Regarding the blurring in the image, the degree of dot diffusion when the printed sample was left at 60 ° C. for 200 hours was observed and evaluated according to the following criteria. The results are shown in Table 1. 1: It can be seen with the naked eye that the printed matter is carrot. 2: It can be seen with the naked eye that the printed matter is a little carrot. 3: Observing with a magnifying glass, you can see bleeding. 4: When observing with a magnifying glass, you can see that it is a little carrot. 5: No bleeding is observed even when observed with a magnifying glass.

[0040]

[Table 1]

[0041]

The effect of the present invention is that a synthetic resin film having a porous structure, which is attached to one or both sides of a core material,
By providing a heat-resistant surface layer made of a radiation-curable resin and further providing an image-receiving layer thereon, a high-sensitivity, high-gloss thermal transfer image-receiving sheet can be formed, and the radiation-curable resin has an acryloyl equivalent of 190 or less. By using the above resin, it was possible to obtain an image receiving sheet for thermal transfer without image blurring.

Claims (5)

[Claims] 1. A thermal transfer image-receiving sheet comprising an image-receiving layer on the surface of a support, the image-receiving layer receiving a dye that migrates from a thermal transfer medium by heat fusion or sublimation when heated, wherein the support is porous on at least one side of a core material. A synthetic resin film having a body structure is adhered, and a heat resistant surface layer made of a radiation curable resin is provided on the non-adhered side of the film, and further on the heat resistant surface layer of the support. An image-receiving sheet for thermal transfer, characterized in that the image-receiving layer is provided on. 2. The thermal transfer image-receiving sheet according to claim 1, wherein the core material is a cellulose fiber paper or a synthetic resin film. 3. The image transfer sheet for thermal transfer according to claim 1, wherein the synthetic resin film having a porous structure has a density of 85% or less with respect to a non-porous film made of the same material. 4. The thermal transfer according to claim 1, 2 or 3, wherein the radiation curable resin is a compound having an acryloyl group in the molecule, and the acryloyl equivalent of the compound is 190 or less. Image receiving sheet. 5. The image-receiving sheet for thermal transfer according to claim 1, wherein the image-receiving layer contains inorganic fine particles and a dye-staining binder.