JPH04298393A - Image-receiving sheet for thermal transfer recording - Google Patents

Abstract

PURPOSE:To obtain an image-receiving sheet for heat-sensitive recording, from which an image having high density is acquired even by low energy and which has the excellent heat-resistance shelf stability of the image, by incorporating a specific copolymer and/or graft polymer in an image-receiving layer. CONSTITUTION:An image-receiving layer is formed of a binder for the image- receiving layer and various additives. The copolymer of a monomer selected from the compound group of propylene, acrylonitrile, isobutylene, itaconic acid and crotonic acid and these alkyl ester, vinyl halide, and olefin halide and vinyl chloride or a graft polymer obtained by grafting an oligomer or a linear polymer using said compound group or an aromatic group unsaturated compound including styrene, chlorostyrene, vinyl benzoate and benzoyl vinyl ether as a monomer to a vinyl chloride resin is employed.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention relates to an image-receiving sheet for thermal transfer recording, and more specifically, the present invention relates to an image-receiving sheet for thermal transfer recording. The present invention relates to an image-receiving sheet for thermal transfer recording, which is used to perform image recording by thermally transferring the image.

[Prior art and problems to be solved by the invention] In recent years, inkjet,
Color recording technologies using electrophotography, thermal transfer, etc. are being considered.

Among these, the thermal transfer method in particular has many advantages, such as ease of operation and maintenance, the ability to make the device smaller, and the ability to reduce costs.

This thermal transfer method includes a method in which a transfer sheet having a meltable ink layer on a support is imagewise heated by a laser or a thermal head to melt and transfer the meltable ink layer onto a transfer sheet. A thermal diffusion transfer method (sublimation transfer method) in which only the heat diffusible dye is diffusely transferred to a transfer sheet using a transfer sheet having an ink layer containing a heat diffusible dye (for example, a sublimable dye) on a support. There are two types.

The latter thermal diffusion transfer method can control the gradation of an image by changing the amount of heat-diffusible dye transferred in response to changes in the thermal energy of the thermal head.

Therefore, the thermal diffusion transfer method has been attracting attention in recent years as a method that can transfer and record a color image having continuous changes in color density by overlapping recording of cyan, magenta, and yellow.

On the other hand, as a typical image-receiving sheet for thermal transfer recording used in the above-mentioned thermal transfer recording method, there can be mentioned a laminated sheet formed by forming a polyester resin layer on the surface of a base material.

In this image-receiving sheet for thermal transfer recording, a thermoplastic resin or a cured product thereof is generally used as the receiving layer, and specifically, polyester resins and vinyl chloride resins are known as typical examples.

Although polyester resins have the advantage of being able to obtain high density, it is generally well known that they have drawbacks such as being prone to fusion and having poor light resistance of dyes after forming an image.

The present inventors have already reported that vinyl chloride resin (vinyl chloride resin includes various vinyl chloride copolymers) is preferable as the resin for the image-receiving layer in order to improve the above-mentioned problems. (Japanese Patent Application Laid-open No. 60-24996).

Since then, there have been reports on the use of vinyl chloride resins in image-receiving layers.

For example, JP-A-61-283595, JP-A-61-283-595;
51181, 64-5886, JP 1-28848
7, 2-38092, 2-67194, 2-59
4, 1-160681, 2-59294, 2-5
9396, 2-9589, 1-271291, 2
-95890, 2-98493, 2-184493
, 2-184494, 2-113992, 2-1
07484, 2-108591, 2-200489
Examples include.

However, although vinyl chloride resin has better light resistance than polyester resin, other monomers are used to increase image density, improve fixing performance and bleed-out, or improve solubility in solvents. Alternatively, if it is copolymerized or modified with a polymer, the heat resistance originally possessed by vinyl chloride resin will deteriorate, causing problems such as discoloration of fixing dyes and coloring of the image-receiving sheet itself during storage. was.

The present inventors have made further improvements using vinyl chloride resin, and as a result, have arrived at the present invention.

That is, the object of the present invention is to obtain a high-density image even with low thermal energy, to avoid fusion with an ink sheet for thermal transfer recording during thermal transfer, and to provide an image with excellent heat-resistant storage stability and dye fixability. An object of the present invention is to provide an image-receiving sheet for thermal transfer recording.

[Means for Solving the Problems] The present invention to achieve the above objects includes a copolymer of vinyl chloride and a monomer selected from the following group A, and/or a vinyl chloride resin containing the following group A or vinyl chloride. This is an image-receiving sheet for thermal transfer recording, characterized in that the image-receiving layer contains an oligomer having an aromatic unsaturated compound as a monomer or a graft polymer grafted with a linear polymer.

Group A: propylene, acrylonitrile, isobutylene,
Icotanic acid, crotonic acid and their alkyl esters, vinyl monohalides, halogenated olefins.

The present invention will be explained in detail below.

[1] Image-receiving sheet for thermal transfer recording The image-receiving sheet for thermal transfer recording can be composed of a support and an image-receiving layer formed thereon.

In some cases, an image-receiving sheet for thermal transfer recording can also be formed with a self-supporting image-receiving layer.

In the image-receiving sheet for thermal transfer recording made of this self-supporting image-receiving layer, there is no need to use a support, so the manufacturing process and the number of parts can be reduced.

-Image-receiving layer- This image-receiving layer can be formed from an image-receiving layer binder and various additives. In some cases, the image-receiving layer may be formed from only the binder.

1. Binder In the present invention, it is important to use at least a heat-resistant thermoplastic resin as the binder for the image-receiving layer.

In general, vinyl chloride resins are easily copolymerized with vinyl chloride, such as alkyl esters of unsaturated fatty acids (vinyl acetate, vinyl propionate, etc.), acrylic acid and its alkyl esters (methylmaleic acid and its alkyl esters (diethyl, dibutyl, etc.), dioctyl, etc.)
, vinylidene chloride, etc. are known, and copolymers with these have good solubility and can be used as resins for image-receiving layers, but the inventors have found that they are inferior to vinyl chloride alone in terms of thermal stability. This has become clear through experiments.

On the other hand, the specific thermoplastic resin used in the present invention, that is, a copolymer of a monomer selected from the following group A and vinyl chloride, or an oligomer or wire containing a vinyl chloride resin and the following group A or B as a monomer. A grafted polymer obtained by grafting a polymer with a shape of 10% has good thermal stability.

Group A: propylene, acrylonitrile, isobutylene,
Icotanic acid, and crotonic acid and their alkyl esters, vinyl monohalides, halogenated olefins.

Group B: Aromatic unsaturated compounds including styrene, chlorostyrene, vinyl benzoate, and benzoyl vinyl ether.

The above copolymer and graft polymer may be used alone or in combination.

The thermoplastic resin preferably has a Tg of 20 to 120°C. If this Tg is less than 20° C., problems such as fusion of the image-receiving sheet for thermal transfer recording may occur. Moreover, when Tg exceeds 120° C., the sensitivity of the image-receiving layer tends to decrease.

The molecular weight is not particularly limited, but may be within a range that does not impair the solubility, dispersibility, or coatability after dissolution or dispersion of the graft polymer.

The composition ratio of monomers, oligomers, and polymer parts other than vinyl chloride is preferably within a range that does not impair thermal stability;
The content is preferably 0% by weight or less.

2. Additives Release agents, antioxidants, UV absorbers, light stabilizers, fillers (inorganic fine particles, organic resin particles), and pigments may be added to the image-receiving layer. Furthermore, a plasticizer, a hot solvent, etc. may be added as a sensitizer.

The release agent can improve the releasability between the ink sheet for thermal transfer recording and the image receiving sheet for thermal transfer recording.

Such release agents include silicone oil (including what is called silicone resin); solid waxes such as polyethylene wax, amide wax, and Teflon powder; fluorine-based and phosphoric acid ester-based surfactants, etc. Among them, silicone oil is preferred.

There are two types of silicone oil: one is a type that is added to a car (simple addition type), and the other is a type that is cured or reacted (curing reaction type).

In the case of a simple addition type, it is preferable to use modified silicone oil in order to improve compatibility with the binder.

As modified silicone oil, polyester modified silicone resin (or silicone modified polyester resin)
, acrylic-modified silicone resin (or silicone-modified acrylic resin), urethane-modified silicone resin (or silicone-modified urethane resin), cellulose-modified silicone resin (or silicone-modified cellulose resin), alkyd-modified silicone resin (or silicone-modified alkyd) resin), epoxy-modified silicone resin (or silicone-modified epoxy resin), and the like.

Specifically, polyester-modified silicone resin containing polysiloxane resin in the main chain and copolymerized with polyester in block form, silicone-modified polyester resin having dimethylpolysiloxane moiety as a side chain bonded to the polyester main chain, and dimethylpolyester resin. Block copolymers, alternating copolymers, graft copolymers, random copolymers, etc. of siloxane and polyester can also be used as modified silicone oils or resins.

In particular, in the present invention, it is preferable to add a polyester-modified silicone resin.

Typical polyester-modified silicone resins include, for example, a copolymer of diol and dibasic acid, or a block copolymer of polyester, which is a ring-opening polymer of caprolactone, and dimethylpolysiloxane (both ends or one end of dimethylpolysiloxane). Contains a copolymer in which the terminal end is blocked with the above polyester moiety, or conversely, the above polyester is blocked with dimethylpolysiloxane), or the above polyester is used as the main chain and (dimethyl)polysiloxane is bonded to the side chain. At least one copolymer can be mentioned.

The amount of these simple addition type silicone oils cannot be determined uniformly as it may vary depending on the type of silicone oil, but generally speaking, it is usually The amount is 0.5 to 50% by weight, preferably 1 to 20% by weight.

Curing reaction type silicone oils include reaction curing type,
Examples include photo-curing type and catalyst-curing type.

Examples of reaction-curing silicone oils include those obtained by reaction-curing amino-modified silicone oil and epoxy-modified silicone oil.

In addition, as catalyst curing type or photo curing type silicone oil, KS-705F-PS, KS-705F-PS-
1. KS-770-PL-3 [all catalyst curing silicone oils: manufactured by Shin-Etsu Chemical Co., Ltd.], KS-720
, KS-774-PL-3 [all photocurable silicone oils: manufactured by Shin-Etsu Chemical Co., Ltd.], and the like.

The amount of these curable silicone oils added is preferably 0.5 to 30% by weight of the binder for the image-receiving layer.

Note that a release agent layer can also be provided by dissolving or dispersing the above-mentioned release agent in a suitable solvent and applying the solution to a part of the surface of the image-receiving layer, followed by drying.

Next, as the antioxidant, JP-A-59-18278
5, 60-130735, JP-A-1-127387, etc., and compounds known to improve image durability in photographs and other image recording materials.

As the UV absorber and light stabilizer, JP-A-59-
158287, 63-74686, 63-1450
89, 59-196292, 62-229594,
Examples include compounds described in JP-A No. 63-122596, JP-A No. 61-283595, and JP-A-1-204788, as well as compounds known to improve image durability in photographs and other image recording materials.

Examples of the filler include inorganic fine particles and organic resin particles.

These inorganic fine particles include silica gel, calcium carbonate,
Examples of the organic particles include titanium oxide, acid clay, activated clay, and alumina. Examples of organic fine particles include resin particles such as fluororesin particles, guanamine resin particles, acrylic resin particles, and silicone resin particles.

These inorganic/organic resin particles vary depending on their specific gravity, but the
．． Addition of 1 to 70% by weight is preferred.

Typical examples of the pigment include titanium white, calcium carbonate, zinc oxide, barium sulfate, silica, talc, clay, kaolin, activated clay, acid clay, and the like.

Examples of the plasticizer include phthalate esters (for example, dimethyl phthalate, dibutyl phthalate, dioctyl phthalate,
didecyl phthalate, etc.), trimellitic acid esters (
For example, trimellitic acid octyl ester, trimellitic acid isononyl ester, trimellitic acid isodesol ester, etc.), pyromellitic acid esters such as pyromellitic acid octyl ester, adipate esters (dioctyl adipate, methyl lauryl adipate, etc.) , di-2-ethylhexyl adipate, ethyl lauryl adipate, etc.), other oleic acid esters, succinic acid esters, maleic acid esters, sebacic acid esters, citric acid esters, cystearic acid epoxy, and Orthophosphoric acid esters such as triphenyl phosphate and tricresyl phosphate, phosphorous esters such as triphenyl phosphite and trisene phosphite, and glycol esters such as ethyl phthalyl ethyl glycolate and butylphthalyl butyl glycolate. Examples include.

In the present invention, the total amount of additives added is usually in the range of 0.1 to 50% by weight based on the binder for the image-receiving layer.

-Support- Examples of the support for the image-receiving sheet for thermal transfer recording include paper, coated paper, synthetic paper (polypropylene, polystyrene, or a composite material made of paper and paper), white polyethylene terephthalate base film, transparent polyethylene. Examples include terephthalate-based films, transparent polyethylene naphthalate films, and polyolefin-coated papers.

The thickness of the support is usually 20 to 300 μm, preferably 30 μm.
~300 μm.

[2] Manufacture of image-receiving sheet for thermal transfer recording Image-receiving sheets for thermal transfer recording are prepared by dispersing or dissolving the components forming the image-receiving layer in a solvent to prepare a coating solution for the image-receiving layer, and then applying the coating solution for the image-receiving layer. It can be manufactured by a coating method in which a liquid is applied to the surface of a support and dried.

Further, it can also be manufactured by a mixing lamination method using components that form the image-receiving layer.

Examples of the solvent used in the coating method include conventionally known solvents such as water, alcohol, methyl ethyl ketone, toluene, dioxane, and cyclohexanone.

When employing the lamination method, a coextrusion method may also be employed.

The image receiving layer may be formed over the entire surface of the support, or may be formed on a part of the surface of the support.

The thickness of the image-receiving layer formed on the surface of the support is generally 2 to 2.
It is about 50 μm, preferably about 3 to 20 μm.

On the other hand, when the image-receiving layer itself forms an image-receiving sheet for thermal transfer recording because the image-receiving layer is self-supporting, the thickness of the image-receiving layer is 60 to 200 μm, preferably 90 μm to 1
It is about 50 μm.

In addition, in this image-receiving sheet for thermal transfer recording, in order to more effectively prevent fusion with the ink layer of the ink sheet for thermal transfer recording, a release material (silicon resin, modified silicone resin as described above) is added to the surface of the image-receiving layer. , a silicone oil film or a cured product thereof) may be further laminated.

The thickness of this release layer is usually 0.03 to 2.0 μm.

Further, in the image-receiving sheet for thermal transfer recording of the present invention, a cushion layer may be provided between the support and the image-receiving layer. By providing a cushion layer, noise is reduced and an image corresponding to image information can be transferred and recorded with good reproducibility.

Examples of the material constituting the cushion layer include urethane resin, acrylic resin, ethylene resin, butadiene rubber, and epoxy resin.

The thickness of the cushion layer is usually 1 to 50 μm, preferably 3 to 30 μm.

[3] Ink sheet for thermal transfer recording Thermal transfer recording (image formation) requires an ink sheet for thermal transfer recording to be used as a pair with an image-receiving sheet for thermal transfer recording.

This ink sheet for thermal transfer recording can be composed of a support described later and an ink layer formed thereon.

-Ink layer- The ink layer basically contains a heat-diffusible dye and a binder.

1. Heat-diffusible dyes Examples of heat-diffusible dyes include cyan dyes, magenta dyes, and yellow dyes.

As the cyan dye, JP-A-59-78896;
No. 59-227948, No. 60-24966, No. 6
No. 0-53563, No. 60-130735, No. 60-
No. 131292, No. 60-239289, No. 61-1
No. 9396, No. 61-22993, No. 61-3129
No. 2, No. 61-31467, No. 61-35994,
No. 61-49893, No. 61-148269, No. 6
No. 2-191191, No. 63-91288, No. 63-
Examples include naphthoquinone dyes, anthraquinone dyes, and azomethine dyes described in publications such as No. 91287 and No. 63-290793.

Examples of the magenta dye include JP-A-59-78896, JP-A-60-30392, and JP-A-60-30394.
No., JP-A-60-253595, JP-A-61-262
No. 190, JP-A-63-5992, JP-A-63-20
No. 5288, JP-A-64-159, JP-A-64-63
Examples include anthraquinone dyes, azo dyes, and azomethine dyes described in various publications such as No. 194.

As yellow pigments, JP-A-59-78896, JP-A-60-27594, JP-A-60-31560,
Methine dyes, azo dyes, quinophthalone dyes, which are described in JP-A-60-53565, JP-A-61-12394, JP-A-63-122594, etc.
Examples include anthrisothiazole dyes.

Particularly preferable heat-diffusible dyes are those obtained by a coupling reaction of a compound having a closed or closed active methylene group with an oxidized product of p-phenylenediamine derivative or an oxidized product of p-aminophenol derivative. It is an indoaniline dye obtained by a coupling reaction between an azomethine dye and an oxidized product of a phenol or naphthol derivative, a p-phenylenediamine derivative, or an oxidized product of a p-aminophenol derivative.

The heat-diffusible dye contained in the ink layer may be any of yellow dye, magenta dye, and cyan dye, as long as the image to be formed is a single color.

Furthermore, depending on the color tone of the image to be formed, it may contain two or more of the three types of dyes or other heat-diffusible dyes.

The amount of the heat-diffusible dye used is usually 0.1 to 20 g, preferably 0.2 to 5 g per m 2 of the support.

2. Binder As a binder, cellulose resins such as ethyl cellulose, hydroxyethyl cellulose, ethyl hydroxyethyl cellulose, hydroxypropyl cellulose, methyl cellulose, cellulose acetate, cellulose acetate butyrate, etc.
Polyvinyl alcohol, polyvinyl formal, polyvinyl butyral, polyvinylpyrrolidone, polyester, polyvinyl acetate, polyacrylamide, polyvinyl acetoacetal, styrene resin, styrene copolymer resin, polyacrylic acid ester, polyacrylic acid, acrylic acid copolymer, rubber Examples include resins based on resins, ionomer resins, and olefin resins.

Among these resins, polyvinyl butyral, polyvinyl acetoacetal, or cellulose resins, which have excellent acid resistance, are preferred.

The above-mentioned various binders can be used alone or in combination of two or more.

The weight ratio of the binder and the heat diffusible dye is 1:10.
-10:1 is preferred, and a range of 2:8-8:2 is particularly preferred.

3. Other optional components Furthermore, various additives can be added to the ink layer within a range that does not impede the object of the present invention.

As additives, silicone resin, silicone oil (
Reaction curing type is also available), silicone modified resins, fluororesins, surfactants, and release compounds such as waxes, fillers and binder components such as fine metal powders, silica gel, metal oxides, carbon black, and fine resin powders. curing agents (for example, radiation active compounds such as isocyanates, acrylics, and epoxies) that can react with

Furthermore, examples of additives include heat-melting substances for promoting transfer, such as waxes and higher fatty acid esters, which are described in JP-A-59-106997.

-Support- Any support for the ink sheet for thermal transfer recording may be used as long as it has good dimensional stability and can withstand the heat during recording with a thermal head, but thin paper such as condenser paper or glassine paper may be used. Heat resistant plastic films such as , polyethylene terephthalate, polyethylene naphthalate, polyamide, polycarbonate, polysulfone, polyvinyl alcohol cellophane, polystyrene can be used.

The thickness of the support is preferably 2 to 10 μm, and the support may have a subbing layer for the purpose of improving adhesion with the binder and preventing transfer and dyeing of the dye to the support. good.

Furthermore, an anti-sticking layer may be provided on the back surface of the support (the side opposite to the ink layer) in order to prevent the head from adhering, sticking, or wrinkling the support.

The thickness of this anti-sticking layer is usually 0.1 to 1 μm.
It is m.

The shape of the support is not particularly limited, and may be of any shape, such as a wide sheet or film, or a narrow tape or card.

[4] Manufacture of ink sheet for thermal transfer recording The ink sheet for thermal transfer recording is produced by preparing a coating liquid for forming an ink layer by dispersing or dissolving the various components forming the ink layer in a solvent, and then applying the coating liquid. It can be manufactured by coating the surface of a support and drying it.

Note that one or more of the binders are used by dissolving them in a solvent or dispersing them in a latex form.

The solvents include water, alcohols (e.g. ethanol, propanol), cellosolves (e.g. methyl cellosolve, ethyl cellosolve), aromatics (e.g. toluene, xylene, chlorobenzene), ketones (e.g. acetone, methyl ethyl ketone), esters. (eg, ethyl acetate, butyl acetate, etc.), ethers (eg, tetrahydrofuran, dioxane), chlorinated solvents (eg, chloroform, trichloroethylene), and the like.

For the above-mentioned coating, conventional methods such as a sequential coating method using a gravure roll, an extrusion coating method, a wire bar coating method, a roll coating method, etc. can be employed.

The ink layer may be formed as a layer containing a monochromatic heat-diffusible dye on the entire surface or a part of the surface of the support, or a yellow ink layer containing a binder and a yellow dye, or a layer containing a binder and a yellow dye. Even if a magenta ink layer containing a binder and a magenta dye and a cyan ink layer containing a binder and a cyan dye are formed on the entire surface or a part of the surface of the support in a constant repetition along the planar direction, good.

Further, in addition to the three ink layers arranged along the plane direction, a black ink layer containing a black image forming substance may be interposed.

Note that with regard to the black ink layer, clear images can be obtained with either the diffusion transfer type or the melt transfer type.

The thickness of the ink layer thus formed is usually 0.2~
The thickness is 10 μm, preferably 0.3 to 3 μm.

In the present invention, convenience in use can be achieved by forming perforations on the ink sheet for thermal transfer recording, or providing detection marks for detecting the positions of areas with different hues.

Note that the ink sheet for thermal transfer recording is not limited to the structure consisting of a support and a heat-sensitive layer formed thereon, and other layers may be formed on the surface of the ink layer.

For example, an overcoat layer may be provided for the purpose of preventing fusion with the image-receiving sheet for thermal transfer recording and setting-off (blocking) of the heat-diffusible dye.

[5] Image formation To form an image, the ink layer of the ink sheet for thermal transfer recording and the image-receiving layer of the image-receiving sheet for thermal transfer recording are overlapped, and thermal energy is applied imagewise to the interface between the ink layer and the image-receiving layer. give.

Then, the heat-diffusible dye in the ink layer is vaporized or sublimated in an amount corresponding to the applied thermal energy, transferred to the image-receiving layer side, and received.

As a result, an image is formed on the image receiving layer.

In the present invention, since the image-receiving layer of the image-receiving sheet for thermal transfer recording contains a specific thermoplastic resin, high thermal energy is not required to obtain the required image density. That is, a high density image can be obtained even with low thermal energy (high sensitivity).

Further, the fixability of the dye transferred from the ink sheet for thermal transfer recording is good.

Furthermore, the image is less likely to be discolored or colored due to heat or the like during storage, and therefore the image quality at the time of image formation can be maintained. Furthermore, it is also possible to prevent fusion with the thermal transfer recording ink sheet during thermal transfer recording.

A thermal head is generally used as a heat source for providing the thermal energy, but other known sources such as a laser beam, an infrared flash, and a thermal pen can also be used.

When a thermal head is used as a heat source for providing thermal energy, the applied thermal energy can be varied continuously or in multiple stages by modulating the voltage or pulse width applied to the thermal head.

When a laser beam is used as a heat source for providing thermal energy, the amount of thermal energy provided can be changed by changing the amount of laser light or the irradiation area.

In this case, in order to facilitate the absorption of laser light, a laser light absorbing material (for example, in the case of a semiconductor laser, carbon black, an infrared absorbing substance, etc.) may be present in the ink layer or near the ink layer.

If a dot generator with a built-in acousto-optic element is used, thermal energy can be applied depending on the size of the halftone dot.

When using a laser beam, it is preferable to bring the ink sheet for thermal transfer recording and the image-receiving sheet for thermal transfer recording into close contact with each other.

When using an infrared flash lamp as a heat source that provides thermal energy, as with laser light,
Heating is preferably performed through a colored layer such as black. Alternatively, heating may be performed through a pattern or halftone dot pattern that continuously expresses the shading of an image, such as black, or a colored layer such as black and a negative pattern corresponding to the negative of the above pattern. Heating may be performed in combination.

Thermal energy may be applied from the ink sheet side for thermal transfer recording, from the image receiving sheet side for thermal transfer recording, or from both sides, but if priority is given to effective use of thermal energy, It is desirable to perform this from the ink sheet side for thermal transfer recording.

By the above thermal transfer recording, a one-color image can be recorded on the image-receiving layer of the image-receiving sheet for thermal transfer recording, but according to the method described below, it is also possible to obtain a color photographic color image consisting of a combination of various colors.

For example, sequentially replace the yellow, magenta, cyan, and, if necessary, black heat-sensitive sheets for thermal transfer recording.
By performing thermal transfer according to each color, it is also possible to obtain a color photographic color image consisting of a combination of each color.

The following method is also effective.

That is, instead of using ink sheets for heat-sensitive transfer recording of each color as described above, an ink sheet for heat-sensitive transfer recording is used that has areas pre-painted in each color.

Then, first, the yellow area is used to thermally transfer the yellow color separation image, then the magenta area is used to thermally transfer the magenta color separation image, and then the process is repeated sequentially to create yellow, magenta, cyan, and the necessary A method is adopted in which the image is thermally transferred in order with the black separated color image.

Although it is possible to obtain a color photographic-like color image with this method as well, this method has the further advantage that there is no need to replace the heat-sensitive sheet for heat-sensitive transfer recording as described above.

[Example] Next, the present invention will be described in more detail with reference to Examples and Comparative Examples. In addition, in the following, "parts" are "parts by weight"
means.

(Example 1) On the corona-treated surface of a 6 μm thick polyethylene terephthalate film [manufactured by Toray Industries, Inc.] as a support,
A coating solution for forming an ink layer having the following composition is applied by wire bar coating method to a thickness of 1 μm after drying, and at the same time, silicone oil [manufactured by Shin-Etsu Silicone Co., Ltd.] is applied to the back surface that has not been corona treated. X-41
, 4003A,] was applied with a dropper and spread over the entire surface, and a backside treatment coat was performed to obtain an ink sheet for thermal transfer recording.

Coating liquid for ink layer formation Dispersed dye [manufactured by Nippon Kayaku Co., Ltd.,...4 parts Kayaset Blue 136] Polyvinyl butyral...5 parts [degree of polymerization 1700, manufactured by Block Chemical Industry Co., Ltd., trade name BX
-1] Methyl ethyl ketone...90 parts Cyclohexanone...5 parts Next, an image-receiving layer having the following composition was formed on a 150 μm thick synthetic paper [manufactured by Oji Yuka Synthetic Paper Co., Ltd., Yupo FPG-150] as a support. After applying the coating solution using the wire bar coating method and temporarily drying it with a dryer,
The mixture was dried in an oven at 00° C. for 1 hour to obtain an image-receiving sheet for thermal transfer recording in which an image-receiving layer with a thickness of 5 μm was formed on synthetic paper.

Coating liquid for image-receiving layer formation Vinyl chloride/acrylonitrile copolymer, 9 parts Polyester modified silicone resin...1 part [manufactured by Shin-Etsu Silicon Co., Ltd., X-24-8300] Methyl ethyl ketone...20
Part: Cyclohexanone: 20 parts Next, the ink sheet for thermal transfer recording and the image receiving sheet for thermal transfer recording are overlapped so that the surface of the ink layer of the former is in contact with the surface of the image receiving layer of the latter, and thermal transfer recording is performed. Using a thermal head from the support side of the ink sheet, output 0.4 W/dot, pulse width 0.3 to 10 msec,
Image recording was performed by heating at a dot density of 6 dots/mm.

After the image was recorded, the transfer density on the surface of the image-receiving layer of the ink sheet for thermal transfer recording and the image-receiving sheet for thermal transfer recording and the heat-resistant storage stability of the image were evaluated according to the following criteria.

The results are shown in Table 1.

Transfer density: The reflection density OD value was measured using an optical densitometer.

〇…OD value is 2.0 or more.

Δ...OD value is 1.7 to 2.0.

X...OD value is 1.7 or less.

Heat-resistant storage stability: The image-receiving sheet for thermal transfer recording on which an image was recorded was kept in an environment of 77° C. and 80% relative humidity for 72 hours, and the presence or absence of discoloration and bleed-out of the dye was examined.

Discoloration…Visual evaluation ○…Almost no discoloration ×…Discolored bleed out ○…Pigment remains even if you rub the image with your hand. is difficult to fall off.

X...If you rub the image with your hand, the pigment will come out. drop down.

(Example 2) The same procedure as in Example 1 was carried out except that the coating liquid for forming an image-receiving layer in Example 1 had the following composition.

The results are shown in Table 1.

Coating liquid for image-receiving layer formation Vinyl chloride/icotanoic acid copolymer...5 parts Vinyl chloride resin...4 parts [manufactured by Shin-Etsu Chemical Co., Ltd., TK-300, degree of polymerization 300
] Urethane-modified silicone resin...1 part [manufactured by Dainichiseika Co., Ltd., Dialomer-SP-712] Methyl ethyl ketone...20 parts cyclohexanone...20 parts (Example 3) Coating for forming the image-receiving layer in Example 1 The same procedure as in Example 1 was carried out except that the composition of the working solution was changed to the following composition.

The results are shown in Table 1.

Coating liquid for image-receiving layer formation Styrene graft vinyl chloride resin...9 parts Polyester modified silicone resin...0.5 part [manufactured by Shin-Etsu Silicon Co., Ltd., X
-24-8300] trimellitic acid alkyl ester...
0.5 part [manufactured by Asahi Denka Co., Ltd., C-79] Methyl ethyl ketone...20 parts Cyclohexanone...20 parts (Comparative Example 1) Vinyl chloride, which is a component of the coating liquid for forming an image-receiving layer in Example 1 - The same procedure as in Example 1 was carried out except that the acrylonitrile copolymer resin was replaced with vinyl chloride.

The results are shown in Table 1.

(Comparative Example 2) Comparative Example 2 was carried out in the same manner as in Example 1 except that the composition of the coating liquid for forming an image-receiving layer in Example 1 was changed to the following composition.

The results are shown in Table 1.

Coating liquid for forming image-receiving layer Vinyl chloride/methyl acrylate copolymer...9 parts Polyester-modified silicone...1 part [manufactured by Shin-Etsu Silicon Co., Ltd., X-24-8300] [Effects of the invention] Thermal transfer of the invention Image-receiving sheets for recording can produce high-density images even with low thermal energy, and have excellent heat-resistant storage properties.
Since it has excellent dye fixing properties, it is possible to maintain high quality images.

Claims (1)

[Claims] Claim 1: A copolymer of a monomer selected from the following group A and vinyl chloride, and/or an oligomer or linear polymer containing the following group A or an aromatic unsaturated compound as a monomer in a vinyl chloride resin. An image-receiving sheet for thermal transfer recording, characterized in that the image-receiving layer contains a kraft polymer. Group A: propylene, acrylonitrile, isobutylene,
Icotanic acid, crotonic acid and their alkyl esters, vinyl monohalides, halogenated olefins.