JPH0585068A - Image-receiving paper for thermal transfer and method for producing the same - Google Patents

Abstract

(57) [Summary] [Purpose] To manufacture image-receiving paper that has high heat resistance and does not deteriorate gloss even at high temperature printing. [Structure] In a heat-sensitive transfer image-receiving paper comprising a support and a precoat layer containing polyethylene as a main component and an image-receiving layer containing a thermoplastic resin as a main component, a toluene extractable gel fraction of polyethylene is 20%. A heat-sensitive transfer image-receiving paper characterized by being processed as described above and a method for producing the same. [Effect] Since the gel fraction at a high temperature is high, polyethylene does not cause heat shrinkage, and as a result, gloss is not reduced during printing, and a thermal transfer image receiving paper that does not cause blocking with a donor sheet can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention applies an image receiving layer on a precoat layer having a high smoothness and a high temperature gel component as a main component, which is provided on a support, and an image receiving layer is coated on the support to obtain a high quality image.
The present invention also relates to a sublimation type thermal transfer image-receiving paper having excellent gloss in the image area and a method for producing the same.

[0002]

2. Description of the Related Art A sublimation-type thermal transfer printer is used as a means for color hard copy, especially for reproducing multicolor gradation images. The principle of such a sublimation-type thermal transfer type printer is that an image is converted into an electric signal, and the electric signal is further converted into a heat signal by a thermal head so that a sheet (ink donor sheet) coated with a sublimation type ink The heated and sublimated ink is fixed with an image receiving paper that is in close contact with the ink donor sheet, and the image is reproduced.
The surface of such an image receiving paper is generally provided with an image receiving layer for fixing the ink with a polymer such as saturated copolyester, polyacetate and the like.

In the sublimation type thermal transfer type printer, recently, it has been required to increase the printing speed and improve the transferred image quality. When a porous support such as plain paper is used as a support for the image-receiving paper for thermal transfer, the smoothness is low and the image quality is poor. In order to obtain a transferred image having high image quality without image unevenness, the image receiving layer preferably has a high surface smoothness, and the Beck's smoothness needs to be at least 2000 seconds or more, preferably 5000 seconds or more. In order to improve the quality of transferred images, coated paper such as art paper and coated paper, synthetic resin film such as polyethylene, polypropylene, polyethylene terephthalate, polymethylpentene, vinyl chloride, vinylidene chloride, polystyrene and polyamide, or their synthesis It is unavoidable to use laminated paper or synthetic paper in which resin is laminated on one side or both sides.

However, for art paper and coated paper,
Even if an image receiving layer is provided thereon, the smoothness may be slightly lacked and the gloss tends to be poor. The present inventors have previously found that in order to enhance the dyeing property of the sublimation dye to the image receiving layer, it is necessary to increase the adhesiveness between the image receiving layer and the ink donor sheet, and to provide the support with adhesiveness. Was applied for a method of providing an intermediate layer composed of an addition polymerizable composition and a polyolefin resin between a support and an image receiving layer (Japanese Patent Application No. 2-1.
No. 46684). As can be seen from this application, it can be said that a synthetic resin film or a synthetic resin laminated on paper is excellent in terms of gloss and smoothness. Among them, the support used as a precoat layer by laminating polyethylene on paper by melt extrusion is laminated with other synthetic resin, as can be seen from the actual results used as a support for the present silver salt photographs. Cheaper and superior in laminating suitability, ease of production, high gloss, firmness as a support, high surface smoothness, and water-based or organic solvent-based image-receiving layer It has been found that it has excellent adhesiveness with and is an excellent image receiving paper support. However, when melt-extruded polyethylene is used as the precoat layer, polyethylene is inferior in heat resistance,
The high smoothness causes shrinkage due to heat from the thermal head, which reduces surface properties (especially minute wrinkles in the printed area or deterioration of gloss), and non-gel components block ink donor sheets and ink at high temperatures. The image quality may be deteriorated. In particular, this phenomenon tends to increase the printing speed, and when the thermal printing temperature inevitably rises, the above situation tends to be exacerbated.

[0005]

Therefore, the problem to be solved by the present invention is that a high thermal printing temperature is not required in a sublimation type thermal transfer image receiving paper using a polyethylene layer laminated on a support by melt extrusion as a precoat layer. It is to produce a sublimation-type thermal transfer image-receiving paper capable of obtaining a good recorded image without lowering gloss and image quality even when used.

[0006]

Means for Solving the Problems As a result of intensive studies on means for solving the above problems, the present inventors have found the following method. That is, in a heat-sensitive transfer image-receiving paper obtained by laminating a precoat layer containing polyethylene as a main component and an image receiving layer containing a thermoplastic resin as a main component on a support, the polyethylene has a toluene extraction gel fraction of 20. The invention is an image-receiving paper for heat-sensitive transfer, which is characterized in that it is treated so as to have a content of at least%. Such treatment of polyethylene includes the inclusion and reaction of polyfunctional monomers,
Alternatively, it can be obtained by performing electron beam irradiation. That is, the present invention is to increase the high temperature gel component of polyethylene provided on the support by some method to form a support capable of suppressing deterioration of gloss and blocking during thermal transfer recording. Then, a thermoplastic resin layer is applied onto the layer to obtain a sublimation type thermal transfer image-receiving paper having excellent heat resistance.

The present invention will be described in detail below.

The polyethylene used in the precoat layer of the present invention may be any type of polyethylene such as linear low density polyethylene, low density polyethylene, medium density polyethylene and high density polyethylene, and these polyethylenes may be used alone or in combination. It is laminated on the support by melt extrusion to form a precoat layer. As a method of reducing the high temperature non-gel component of polyethylene constituting the precoat, a method of kneading a polyfunctional monomer to react by heating, a method of kneading a polyfunctional monomer and a sensitizer similarly to react with light, chlorine gas And acetylene gas to irradiate with light to introduce chloro or vinyl groups to react with polyfunctional monomer, plasma discharge in dilute acetylene gas to react, ozone-peroxidized to have allyl or acryloyl groups A method of reacting with a polyfunctional monomer, a method of kneading a sensitizer such as benzophenone or N-methyl-2-benzoyl-β-naphthiazoline and reacting with light to react an unsaturated bond in the molecule, light irradiation or generation by γ-ray or electron beam irradiation A method of grafting a radical with a monomer such as acrylic acid,
There are many methods such as crosslinking by electron beam irradiation,
Although any method may be used, the method of crosslinking by electron beam irradiation and the method of kneading a polyfunctional monomer are excellent in terms of uniformity of reaction, easiness, and the like. In polyethylene, if necessary, various additives such as ultramarine, pigments and dyes such as cobalt violet, antioxidants, optical brighteners, antistatic agents, dispersants, stabilizers, release agents are appropriately combined. Can be added.

When using an electron beam, the amount of the electron beam to be irradiated is 0.5 to 50 M in the absorbed dose to polyethylene.
It is desirable to adjust within the range of about rad. 0.5 Mr
If it is less than ad, sufficient irradiation effect cannot be obtained, and 50 Mrad
Even if the amount of electron beam irradiation is increased, the level of cross-linking of polyethylene and the heat resistance hardly change, and the paper or film support is deteriorated, which is not preferable. Irradiation of several Mrads is sufficient when reacting a polyfunctional monomer. As the electron beam irradiation method, scanning method,
A ten-beam method or the like is adopted, and an accelerating voltage for irradiating an electron beam is preferably about 100 to 300 KV. Although the same treatment as electron beam irradiation can be performed using γ rays, the dose density is generally low, which is not preferable as a manufacturing method.
When ultraviolet rays are used for the reaction of the polyfunctional monomer, a photoinitiator and, if necessary, a sensitizer are added. When ultraviolet rays are used, for example, a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, a xenon lamp, a tungsten lamp and the like are preferably used.

The polyethylene used in the present invention must have a toluene extraction gel fraction of 20% or more. The toluene-extracted gel fraction as used herein means the proportion of gel fraction when polyethylene is extracted for 5 minutes with hot toluene at the boiling point, and is a value obtained by the following method. When sublimation type thermal transfer image receiving paper is used, only 1 g of polyethylene in the precoat layer (the amount of polyethylene used) is separated and cut into several sheets, and then the standard maximum diameter is 16 to
Put in a glass filter with a size of 40 μm (Shibata Kagaku Kikai Kogyo Co., Ltd., pore size is G3.5), put the glass filter together with a sufficient amount of boiling hot toluene, and shake for 5 minutes to allow for toluene. It is a value determined by the following mathematical formula 1 according to the amount of polyethylene remaining without being dissolved in toluene (the remaining amount of polyethylene) when a soluble component is extracted and then vacuum dried.

[0011]

[Equation 1] Gel fraction (%) = 100 x polyethylene remaining amount (g) / polyethylene usage amount (g)

As a matter of course, when the polyethylene film contains an inorganic substance such as titanium oxide or zinc oxide, or a substance other than polyethylene, the weight is subtracted from the calculation. Regardless of the type of polyethylene, the toluene extraction gel fraction for 5 minutes is a value of 1% or less as long as it is measured in a film state where crosslinking is not performed.

In the present invention, the image quality of the sublimation type thermal transfer image receiving paper is improved because the gel fraction of polyethylene forming the precoat layer plays a large role. The fact that this improvement in image quality does not depend solely on the superiority or inferiority of the melting property of polyethylene indicates that polyethylene, which clearly showed the effect of improving image quality by electron beam irradiation, and polyethylene before irradiation, were found in thermal analysis. It can also be confirmed from the fact that the melting point range and the heat of fusion per unit weight hardly change. This means that even if polyethylene with an increased amount of high-density polyethylene is used, the effect of improving image quality and suppressing gloss deterioration appears only in a limited temperature range (generally below the melting point of high-density polyethylene). From
It can be seen that in recording at high temperature, the melting point of polyethylene does not significantly affect the image quality.

Examples of the thermoplastic resin used in the present invention include those having an ester bond, such as polyester resin, polyacrylic ester resin, polycarbonate resin, polyvinyl acetate resin and styrene acrylate.
Resins such as polyurethane resins, those having a urethane bond, polyamide resins (nylon) having an amide bond, urea resins having a urea bond, and the like. It can also be used as a copolymer containing at least one of the units as a main component, for example, vinyl chloride-vinyl acetate copolymer, styrene-butadiene copolymer, etc. Further, the above resins may be used alone or in combination of two or more. Can be used. Any of the above-mentioned thermoplastic resins can be preferably used for the purpose of the present invention, but a polyester resin such as a linear saturated polyester resin is preferable for the purpose of increasing dyeability of a sublimation dye and improving transfer density.

The above resin may be dissolved in an organic solvent and applied on a substrate, or it may be emulsified in an aqueous solution and applied on a substrate as an emulsion. If necessary, dye,
Pigment, wetting agent, defoaming agent, dispersant, antistatic agent, release agent,
Additives such as optical brighteners may also be included. Particularly with regard to pigments, it is possible to achieve the purpose of improving blocking by incorporating inorganic particles typified by silica, calcium carbonate, kaolin clay, barium sulfate, titanium oxide, etc. into the thermoplastic resin layer or the radiation-polymerizable composition layer. it can.

Further, a releasing agent can be used for the same purpose. Specifically, solid waxes such as polyethylene wax and amide wax, phosphoric ester type surfactants, Teflon powder, silicone powder and the like. Fluorine-based and silicon-based compounds are listed, but curable silicon compounds are preferably used because it is difficult for blurring of transferred dye and transfer or reduction in image density to occur.

Examples of the curable silicon compound include a thermal reaction curable type, an ultraviolet curable type, an electron beam curable type, and a catalyst curable type, which have an affinity with the image receiving layer component, a releasability from a donor sheet, and a sublimation. It can be appropriately selected and used depending on its affinity with the type dye. These release agents can be used by being dispersed in the image receiving layer, or can be provided as a top coat layer on the image receiving layer. When provided as a top coat, a thermoplastic resin such as a linear polyester resin can be used together with a release agent for the purpose of improving the sensitivity of the image receiving layer.

As the support used in the present invention, in addition to plain paper base paper, non-woven fabric, coated paper such as art paper and coat paper, synthetic resin film, and synthetic paper are used.

In the present invention, the base paper used as the paper support is ordinary natural pulp paper such as glassine paper, high-quality paper, coated paper, synthetic fiber, or so-called synthetic paper obtained by quasi-synthesizing synthetic resin film. However, natural pulp paper containing wood pulp of softwood pulp, hardwood pulp, and mixed softwood pulp as the main component is advantageously used. The thickness of the base paper is not particularly limited, but a smooth one is preferable, and its basis weight is 30 g / m ² to
300 g / m ² is preferred.

In the method of the present invention, the base paper containing natural pulp as a main component, which is advantageously used, may contain various polymer compounds and additives. For example, starch, starch derivatives (cationized starch, phosphate esterified starch, oxidized starch, etc.), polyacrylamide, polyvinyl alcohol, polyvinyl alcohol derivatives (completely saponified, partially saponified, carboxy-modified, cation-modified, and various other modifications). Polyvinyl alcohol), gelatin (alkali treatment, acid treatment, various modified gelatin), etc., dry paper strength enhancer, natural high molecular polysaccharides such as star gum and alginic acid derivatives, higher fatty acid metal salts, rosin derivatives, dialkyl ketones, alkenyls or alkyls. Sizing agents such as succinic anhydride, epoxidized higher fatty acid amides, organic fluoro compounds, dialkylketene dimer emulsions, polyamide polyamine epichlorohydrin resins, melamine resins, urea resins, epoxidized polyamide resins, etc. Paper strength enhancers, stabilizers, pigments, dyes, antioxidants, optical brighteners, various latexes, inorganic electrolytes (sodium chloride, sodium sulfate, sodium phosphate, calcium chloride, lithium chloride, magnesium chloride, magnesium sulfate, chloride) Barium, etc.), pH adjusters, fixing agents such as sulfuric acid bands and aluminum chloride, calcium carbonate, kaolin,
A filler such as talc and clay, and an additive such as an organic conductive agent may be appropriately combined and contained. These contents may be dispersed in the pulp slurry at the papermaking stage, may be added at the tab size after papermaking, and the solution may be applied by various coaters.

Examples of the method for applying the thermoplastic resin on the substrate include blade coating, air doctor coating, squeeze coating, air knife coating, reverse roll coating, gravure roll and transfer roll coating, bar coating and curtain coating. A method is used.

As the polyfunctional monomer contained in the polyethylene used in the present invention, any compound can be used as long as it is a compound having an unsaturated bond which can be polymerized by heat, electron beams or ultraviolet rays. That is, it is a compound having one or more carbon-carbon unsaturated bond, acryloyl group, methacryloyl group, acrylamide group, allyl group,
It is a compound containing a vinyl ether group, a vinyl thioether group, and the like, and examples thereof include acrylic acid alkyl ester, methacrylic acid alkyl ester, acrylonitrile, methacrylonitrile, acrylamide, vinyl acetate, vinyl propionate, and vinylpyrrolidone. There may be two or more unsaturated bonds in the molecule. In particular, unsaturated esters of polyols such as ethylene diacrylate, diethylene glycol diacrylate, glycerol triacrylate, trimethylolpropane triacrylate, pentaerythritol tetraacrylate and the like can be mentioned. A compound having one or more epoxy rings, such as glycidyl acrylate, is also preferable. Furthermore, these compounds may be high molecular weight compounds. Particularly preferred is a compound having an acrylate group at the terminal or side chain of the polymer chain, and examples thereof include a polyester skeleton, a polyurethane skeleton, an epoxy resin skeleton, a polyether skeleton, a polycarbonate skeleton, and a prepolymer having a silicone skeleton. These monomers and prepolymers may be used alone or as a mixture. Further, a polymerization initiator such as a peroxide can be used in combination for the purpose of promoting the thermal reaction.

In the present invention, as the photoinitiator used when treating polyethylene by ultraviolet irradiation, acetophenones such as di- and trichloroacetophenone, benzophenone, Michler's ketone, benzyl, benzoin, benzoin alkyl ether and benzyl dimethyl ketal are used. , Tetramethylthiuram monosulfide, thioxanthones, azo compounds and the like, which are selected from the viewpoints of the type of curing reaction of the ultraviolet curable resin, stability, suitability with an ultraviolet irradiation device, and the like. The amount of the photoinitiator used is usually 0.1 to 5 with respect to the ultraviolet curable resin.
% Range. In addition, a storage stabilizer such as hydroquinone may be used in combination with the photoinitiator.

As the sensitizer used in the present invention, an aliphatic amine, an amine containing an aromatic group, a nitrogen heterocyclic compound,
Allyl urea, O-tolylthiourea, sodium diethyldithiophosphate, soluble salts of aromatic sulfinic acid,
Photo-initiated with N, N-disubstituted-P-aminobenzonitrile compounds, tri-n-butylphosphine, sodium diethylthiophosphate, Michler's ketone, N-nitrosohydroxylamine derivatives, oxazoline compounds, carbon tetrachloride, hexachloroethane, etc. In general, the curing rate can be improved by sharing it with the agent.

When ultraviolet rays are used, it is necessary to add a sensitizer to the radical polymerization composition, and the sensitizer described above can be used appropriately.
As the light source used when performing the treatment by ultraviolet irradiation, for example, a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, a xenon lamp, a tungsten lamp and the like are preferably used.

[0026]

The present invention provides a heat-sensitive transfer image-receiving paper comprising a support and a precoat layer containing polyethylene as a main component and an image-receiving layer containing a thermoplastic resin as a main component, which is laminated for 5 minutes. The invention is an invention of an image-receiving paper for heat-sensitive transfer, which is characterized in that the heat-toluene-extracted gel fraction is 20% or more. The increase in the high-temperature gel component of polyethylene is caused by the use of a polyfunctional monomer or It is achieved by subjecting polyethylene to electron beam irradiation. By treating the polyethylene in this way, the high temperature non-gel component of polyethylene at high temperatures is reduced, and it is possible to suppress the decrease in gloss and the occurrence of blocking during thermal transfer recording. That is, in the present invention, a polyethylene precoat layer provided on a support is increased in gel component by some method, and a thermoplastic resin layer is applied on the layer to obtain a sublimation having excellent heat resistance. To obtain an image-receiving paper for mold-type thermal transfer.

[0027]

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.

Example 1 Low density polyethylene containing 10% by weight of titanium oxide (density 0.918 g / cc) was obtained by performing corona discharge treatment on an art paper having a basis weight of 175 g / m ² and then using a melt extruder.
Was laminated to a resin thickness of 30 μm to form a precoat layer. Electron beam irradiation (accelerating voltage: 200 KV, absorbed dose of about 2 Mra) was applied to the support having this precoat layer.
d) was carried out and the gel fraction of polyethylene was adjusted to 20%. Polyester resin emulsion on polyethylene with an air knife coater (Vylonal MD-1330:
Toyobo) and silica have a dry solid content of 3.0 g / m ² each.
And coated so as to be 0.5 g / m ² and dried to obtain a thermal transfer image-receiving paper.

Example 2 The absorbed dose of polyethylene by electron beam irradiation was about 4 Mra.
An image-receiving paper for thermal transfer was obtained in the same manner as in Example 1 except that d was set and the gel fraction was set to 43%.

Example 3 The absorbed dose of polyethylene by electron beam irradiation was about 8 Mra.
An image-receiving paper for thermal transfer was obtained in the same manner as in Example 1 except that d was set and the gel fraction was set to 55%.

Example 4 A cast paper having a basis weight of 175 g / m ² was subjected to corona discharge treatment, and then 10% by weight of titanium oxide and 3% by weight of a polyfunctional monomer (trimethylolpropane triacrylate) were processed by a melt extruder. And 0.1% polyfunctional silicone resin {1,3-bis (3-methacryloxypropyl) tetrakis (trimethylsiloxy) disiloxane}
High-density polyethylene (density 0.965 g / c
c) was laminated to a resin thickness of 30 μm to form a precoat layer. The polyfunctional monomer was reacted by heating during melt extrusion, and the gel fraction of polyethylene was 20%. Polyester resin emulsion (Vylonal MD-133 on the precoat layer with an air knife coater)
0: Toyobo Co., Ltd.) and silica have a dry solid content of 3.0 g / each
m ² and 0.5 g / m ² to become so coated to obtain an image receiving sheet for thermal transfer and dried.

Example 5 A cast paper having a basis weight of 175 g / m ² was subjected to corona discharge treatment, and then 10% by weight of titanium oxide and 3% by weight of a polyfunctional monomer (dipentaerythritol hexaacrylate) by a melt extruder. , 0.1% polyfunctional silicone resin {1,3-bis (3-methacryloxypropyl) tetrakis (trimethylsiloxy) disiloxane}
And 0.1% photoinitiator (benzyl dimethyl ketal) kneaded into medium density polyethylene (density 0.92
8 g / cc) was laminated to a resin thickness of 30 μm to form a precoat layer. The polyfunctional monomer was heated at the time of melt extrusion and irradiated with ultraviolet rays after lamination to make the gel fraction of polyethylene 35%. On the precoat layer, a polyester resin (Vylon 200:
Toyobo) and silica have a dry solid content of 3.0 g / m ² each.
And 0.5 g / m ² as an ethyl acetate solution and dried to obtain a thermal transfer image-receiving paper.

Example 6 After corona discharge treatment was performed on cast paper having a basis weight of 175 g / m ² , 3% by weight of a polyfunctional monomer (dipentaerythritol hexaacrylate) and 0.1% of a polyfunctional monomer were melted by a melt extruder. Functional density silicone resin {1,3-bis (3-methacryloxypropyl) tetrakis (trimethylsiloxy) disiloxane} kneaded into medium density polyethylene (density 0.928 g / cc) with a resin thickness of 30 μm
To form a precoat layer. The polyfunctional monomer is heated at the time of melt extrusion and irradiated with an electron beam after lamination to reduce the gel fraction of polyethylene to 4%.
It was set to 5%. Gravure co on the precoat layer - data - polyester resin (Byron 200: Toyo Boseki) and silica coating as ethyl acetate solution so that the dry solid content of each 3.0 g / m ² and 0.5 g / m ^2, An image-receiving paper for thermal transfer was obtained by drying.

Comparative Example 1 Low-density polyethylene (density 0.918 g / cc) containing 10% by weight of titanium oxide was subjected to a corona discharge treatment on an art paper having a basis weight of 175 g / m ² and then melt-extruded.
Was laminated to a resin thickness of 30 μm to form a precoat layer. The gel fraction of this polyethylene was 1% or less. Polyester resin emulsion (Vylonal MD-13 on the precoat layer with an air-knife coater)
30: Toyobo) and silica have a dry solid content of 3.0 g each
/ M ² and 0.5 g / m ² , and dried to obtain a thermal transfer image-receiving paper.

Comparative Example 2 Low-density polyethylene containing 10% by weight of titanium oxide (density 0.918 g / cc) after corona discharge treatment was performed on an art paper having a basis weight of 175 g / m ^2.
Was laminated to a resin thickness of 30 μm to form a precoat layer. Electron beam irradiation (accelerating voltage: 2) on this support
00 KV, absorbed dose of about 1 Mrad) was performed to adjust the gel fraction of polyethylene to 15%. Polyester resin emulsion (Vylonal MD-1330: Toyobo) and silica were coated on polyethylene with an air knife coater so that the dry solids would be 3.0 g / m ² and 0.5 g / m ² , respectively. Then, it was dried to obtain an image-receiving paper for heat-sensitive transfer.

Comparative Example 3 A cast paper having a basis weight of 175 g / m ² was subjected to corona discharge treatment, and then 10% by weight of titanium oxide and 0.5% by weight of a polyfunctional monomer (trimethylolpropane trichloride) were used by a melt extruder. Acrylate) and 0.1% polyfunctional silicone resin {1,3-bis (3-methacryloxypropyl) tetrakis (trimethylsiloxy) disiloxane} kneaded in high density polyethylene (density 0.965
g / cc) was laminated to a resin thickness of 30 μm to form a precoat layer. The gel fraction of polyethylene is 10%
Met. Polyester resin emulsion (Vylonal MD-13 on the precoat layer with an air-knife coater)
30: Toyobo) and silica have a dry solid content of 3.0 g each
/ M ² and 0.5 g / m ² , and dried to obtain a thermal transfer image-receiving paper.

Comparative Example 4 A cast paper having a basis weight of 175 g / m ² was subjected to corona discharge treatment, and then 10% by weight of titanium oxide and 1% by weight of a polyfunctional monomer (dipentaerythritol hexaacrylate) by a melt extruder. ), 0.1% polyfunctional silicone resin {1,3-bis (3-methacryloxypropyl) tetrakis (trimethylsiloxy) disiloxane}
And 0.1% photoinitiator (benzyl dimethyl ketal) kneaded into medium density polyethylene (density 0.92
8 g / cc) was laminated to a resin thickness of 30 μm to form a precoat layer. The polyfunctional monomer was heated at the time of melt extrusion and irradiated with ultraviolet rays after lamination to make the gel fraction of polyethylene 15%. On the precoat layer, a polyester resin (Vylon 200:
Toyobo) and silica have a dry solid content of 3.0 g / m ² each.
And 0.5 g / m ² as an ethyl acetate solution and dried to obtain a thermal transfer image-receiving paper.

Test An ink donor sheet was placed over the thus obtained image-receiving paper for thermal transfer in a relative manner, and a constant area (1 cm × 2.5 c) was set by a thermal head capable of freely setting a heating temperature and a heating time.
m) was printed. The temperature at which wrinkles were generated on the polyethylene surface of each sample at a heating time of 0.5 seconds was used as a measure of heat resistance. The surface gloss of the cyan print at 200 ° C. was measured with a gloss meter and evaluated as gloss.
The presence or absence of blocking was visually determined. Regarding gloss, relative evaluation was performed, and one having excellent gloss was judged as O and one having poor gloss was judged as X. Regarding blocking, the state in which nothing was observed was evaluated as ◯, and the state in which it was completely observed was evaluated as ×, and the results are shown in Table-1.

[0039]

[Table 1]

Evaluation In the examples, since the gel fraction of polyethylene in the precoat layer was as high as 20% or more, the fusible content was small in high-temperature printing, blocking with the donor sheet was prevented, and heat shrinkage of polyethylene was also suppressed. Therefore, fine wrinkles do not occur, and therefore gloss does not decrease even after image transfer. In the comparative example, since the gel fraction of polyethylene in the precoat layer is low, the heat resistance is low, and although the printing gloss may be reduced and the use of a silicone compound may reduce the heat resistance, blocking is generally likely to occur.

[0041]

[Effect] In the present invention, a precoat layer containing polyethylene as a main component having a toluene extraction gel fraction of 20% or more melt-extruded on a support and an image receiving layer containing a thermoplastic resin as a main component are laminated. The image-receiving paper for heat-sensitive transfer, which has a precoat layer, has good smoothness and cushioning properties, good adhesion between the image-receiving layer and the ink donor sheet, and the non-gel component of polyethylene at high temperatures is polyfunctional. Since the amount is reduced as compared with untreated polyethylene by using a monomer or by irradiating polyethylene with an electron beam, it is possible to suppress deterioration of gloss and blocking during thermal transfer recording.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Makoto Ishitomi 3-4-2 Marunouchi, Chiyoda-ku, Tokyo Inside Mitsubishi Paper Mills Co., Ltd.

Claims (5)

[Claims] 1. A thermal transfer image-receiving paper comprising a support and a precoat layer containing polyethylene as a main component and an image receiving layer containing a thermoplastic resin as a main component, wherein the precoat layer contains the polyethylene. An image-receiving paper for heat-sensitive transfer, which is a layer melt-extruded on a support and in which the polyethylene of the precoat layer has a toluene extraction gel fraction of 20% or more. 2. The image-receiving paper for heat-sensitive transfer according to claim 1, wherein the polyethylene contains a polyfunctional monomer or a reaction product thereof in the polyethylene. 3. The heat-sensitive transfer image-receiving paper according to claim 1, wherein the polyethylene is electron beam-irradiated polyethylene. 4. A step of laminating polyethylene containing a polyfunctional monomer on a support to form a precoat layer, a step of reacting the polyfunctional monomer, and a thermoplastic resin mainly on the precoat layer. And a step of laminating an image receiving layer as a component. 5. A step of laminating polyethylene on a support to form a precoat layer, a step of irradiating the precoat layer with an electron beam, and an image receiving layer containing a thermoplastic resin as a main component on the precoat layer. A method of manufacturing an image-receiving paper for thermal transfer, comprising a step of laminating.