JPH04115995A - Image receiving sheet for thermal transfer recording - Google Patents

Abstract

PURPOSE:To prevent the fusion with an ink sheet for thermal transfer recording at the time of thermal transfer, to obtain a high density image and to develop the good heat-resistant preservability of an image after thermal transfer by providing an image receiving layer containing a binder resin and an ionomer resin. CONSTITUTION:An image receiving sheet is constituted of a base material 1 and the image receiving layer 2 formed thereon. According to circumstances, said sheet can be formed only from a self-supporting image receiving layer 2a. The image receiving layer contains a binder resin and an ionomer resin. The pref. binder resin is selected from a vinyl chloride resin, polyester, a polyacrylic resin and polycarbonate. The ionomer resin is one having such a structure that a resin having a carboxyl group in its high-molecular side chain is subjected to intermolecular crosslinking by various metal cations and enhances the releasability from a thermal sheet for thermal transfer recording As a result, not only mutual fusion is prevented but also image density can be enhanced even when no high energy is used.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to an image-receiving sheet for thermal transfer recording, and more specifically to an image-receiving sheet for thermal transfer recording, which prevents fusion with an ink sheet for thermal transfer recording, and which can obtain high-density images. The present invention relates to an image-receiving sheet for heat-sensitive transfer recording, which also has excellent heat-resistant storage stability of images.

[Prior Art and Problems to be Solved by the Invention] Conventionally, color recording techniques such as ink sheets, electrophotography, and thermal transfer have been considered as methods for obtaining color hard copies.

Among these, the thermal transfer method in particular has advantages such as easy operation and maintenance, miniaturization of the device, and low cost.

There are two types of this thermal transfer method:

That is, a method in which a transfer sheet having a meltable ink layer on a support is heated imagewise (imagewise) by a laser or a thermal head, and the meltable ink layer is melt-transferred onto an image-receiving sheet for thermal transfer recording. and thermal diffusion transfer, in which the heat-diffusible dye is diffusely transferred to an image-receiving sheet for heat-sensitive transfer recording using an ink sheet for heat-sensitive transfer recording having an ink layer containing a heat-diffusible dye (sublimable dye) on a support. There are two types:

Among these, the thermal diffusion transfer method controls the gradation of the image by changing the amount of dye transferred in response to changes in the thermal energy of the thermal head.
By overlapping magenta and yellow recording,
In recent years, this method has attracted attention as a method for obtaining color images with continuous changes in color shading.

However, this thermal diffusion transfer method has a problem with the image receiving sheet for thermal transfer recording used.

That is, the first problem is that it is difficult to obtain a high density image during thermal transfer unless high thermal energy is applied.

Furthermore, applying high thermal energy will slow down the printing speed and shorten the life of the thermal head.

The second problem is that the images do not have sufficient heat-resistant storage stability.

In other words, if an image-receiving sheet for thermal transfer recording is placed in a high-temperature environment, over a long period of time, the image will become more colored or faded.
Image clarity decreases.

The third problem is that it fuses with the ink sheet for thermal transfer recording during thermal transfer.

The present invention has been made to solve the various problems mentioned above.

That is, one object of the present invention is to prevent fusion with the ink sheet for thermal transfer recording during thermal transfer, to obtain a high-density image, and to maintain good heat-resistant storage stability of the image after thermal transfer. The object of the present invention is to provide an image-receiving sheet for thermal transfer recording that can exhibit excellent performance.

[Means for Solving the Problems] The present invention for achieving the above objects is an image-receiving sheet for thermal transfer recording characterized by having an image-receiving layer containing a binder resin and an ionomer resin.

The present invention will be explained in detail below.

(I) Image-receiving sheet for thermal transfer recording The image-receiving sheet for thermal transfer recording of the present invention is usually composed of a base material 1 and an image-receiving layer 2 formed thereon, as shown in FIG. Something comes up.

Further, the image receiving sheet for thermal transfer recording of the present invention is as follows.

As shown in FIG. 1(b), in some cases, it is possible to form a self-supporting image receiving layer 2a.

In this image-receiving sheet for thermal transfer recording consisting of a self-supporting image-receiving layer, since no base material is used,
It is possible to reduce the number of parts.

Image-receiving layer - In the present invention, the image-receiving layer contains a binder resin and an ionomer resin.

■Binder resin Binder resins include vinyl chloride resins, vinyl chloride resins such as copolymers of vinyl chloride and other monomers (vinyl chloride-vinyl acetate copolymers, etc.), polyesters, polyacrylics (polyacrylic acid esters, etc.)
, polyvinylpyrrolidone, polycarbonate, cellulose triacetate, styrene acrylate resin, vinyltoluene acrylate resin, polyurethane resin, polyamide resin, urea resin, polycaprolactone resin, styrene-maleic anhydride resin, polyacrylonitrile resin, and the like.

Among these binder resins, resins selected from vinyl chloride resins, polyesters, polyacrylics, and polycarbonates are preferred for achieving the purpose of the present invention.

In the present invention, one type of binder resin can be used alone, or two or more types can be used in combination.

The above various resins may be newly synthesized and used, but commercially available products may also be used.

For example, as a commercially available polyester, Byron 200
, Byron 290, Byron 600, etc. [manufactured by Toyobo ■], KA-1038C [manufactured by Arayo Kagaku],
It is possible to use TP22 (1, TP235 [both manufactured by Nippon Gosei Kagaku Kogyo ■], etc.).

The vinyl chloride-vinyl acetate copolymer resin has a vinyl chloride component content of 85 to 97% by weight and a polymerization degree of 200.
~800 is preferred.

The vinyl chloride-vinyl acetate copolymer resin preferably used in the present invention does not necessarily need to be composed only of a vinyl chloride component and a vinyl acetate component; It may also contain ingredients. Examples of such vinyl chloride-vinyl acetate copolymers include S-LEC A,
S-LEC C, S-LEC M [manufactured by Building Blocks Chemical Industry], VINILITE VACH, VINYLITE VYHH, B1
-Light VMCH, Viny Light vYHD, Viny Light V
YLF, Vinylite VYNS, Vinylite VMCC, Vinylite YMCA, Vinylite VACD, Vinylite V
ERR, Vinylite VROH (manufactured by Union Carbide), Denkavinyl 100OG K T, Denkavinyl 100OL, Denkavinyl 100OCK, Denkavinyl 100OA, Denkavinyl 100OLK2. Denkabinir 100OAS, Denkabinir 100100O,
Denkabinir 10ooC8K, Denkabinir 1000C
3, Denkabinir: Jtz1000GK, Denkabinir 1
000G5K, Denkabinir 100OGS, Denkabinir 100OLT, Denkabinir 1000D, Denkabinir 100OW [These include Denki Kagaku Kogyo Kogyo Co., Ltd.].

In any case, from the viewpoint of physical properties, the binder resin has a glass transition point (Tg) of -20 to 150°C.
It is preferable to use a resin in the range of 30 to 120°C, and in terms of molecular weight, it is preferable to use a resin in the range of 30 to 120°C.
,000 to 100,000 is preferred.

In addition, when forming the image-receiving layer, the various resins mentioned above utilize their reactive active sites (if there are no reactive active sites, give them to the resin), and crosslink with radiation, heat, moisture, catalysts, etc. Alternatively, it may be hardened.

In that case, a radiation-active additive such as epoxy or acrylic or a crosslinking agent such as isocyanate may be used.

(2) Ionomer resin In the present invention, it is important that the image-receiving layer contains an ionomer resin.

In general, ionomer resins include DuPont's Surlyn and Mitsui-DuPont Chemical's Himilan.
In a broad sense, the term "ionomer resin" referred to in the present invention, which is a well-known intermolecular metal ion cross-linked resin of ethylene-methacrylic acid polymer, is a resin having a carboxyl group in the side chain of the polymer, which is made of various metal ions. A resin with a structure in which molecules are cross-linked by ions.

An image-receiving sheet for thermal transfer recording containing an ionomer resin in the image-receiving layer improves releasability from the thermal sheet for thermal transfer recording, unlike an image-receiving sheet containing no ionomer resin, thereby preventing mutual fusion.

In addition, it is possible to increase image density (transfer density) without using high thermal energy.

In addition, the heat-sensitive transfer recording image-receiving sheet containing an ionomer in the image-receiving layer has definitely improved heat resistance, and it is difficult for the image to fade or increase color even if stored at high temperatures for a long period of time. The clarity does not decrease.

The reason why such an effect can be obtained by adding an ionomer resin is not entirely clear.Basically, the reason is that the ionomer resin and the binder resin have good compatibility, and that This is thought to be due to the strong bond at the metal ion crosslinking site.

The ionomer resin used in the present invention can be synthesized by polymerizing a polymer containing a carboxyl group, or it is generally a carboxy-modified polymer that dissolves in a solvent and is cross-linked with metal ions after coating. It is preferable to do so.

Carboxy-modified polymers that can be ionomerized in this way include homopolymers or copolymers containing acrylic monomers such as acrylic acid, methacrylic acid, and itaconic acid, and vinyl-based polymers such as carboxylated styrene and carboxylated α-methylstyrene. Polymers containing monomers, carboxy-modified polyesters, carboxy-modified polyurethanes,
Examples include carboxy-modified polyamides and carboxy-modified polystudiene.

The content of carboxyl groups in the carboxy-modified polymer is 50 mol% or less, preferably 3 to 30 mol%.

If it exceeds 50 mol%, the viscosity becomes high and coating suitability becomes poor.

The metal ions that crosslink the carboxy-modified polymer include Na*, K + , Mg2N-1(a
2 *Zn2+, AI”, etc., these are ■CH3
COONa, CHffCOOK, CCH: +C00)
2Ca, (CH3CO0) gZn and other acetates, ■Phosphates, ■ZnO1CaO, MgO and other metal oxides, ■
It is supplied in the form of hydroxide, ■alkoxide such as methoxide and ethoxide.

In the present invention, the amount of the ionomer resin blended in the image-receiving layer is usually 10 to 100% by weight, preferably 2% by weight.
It is 0 to 100% by weight.

If the blending amount is less than 10% by weight, the effects of the present invention will not be fully exhibited.

(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 or the like 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.

Examples of such a release agent include silicone oil; solid waxes such as polyethylene wax, amide wax, and Teflon powder; fluorine-based and phosphoric acid ester-based surfactants; among these, silicone oil is preferred.

There are two types of silicone oil: a type in which it is simply added (simple addition type) and a type in which it is cured or reacted (curing reaction type).

In the case of a simple addition type, it is preferable to use modified silicone oil as the 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), etc.

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 moieties can also be used as modified silicone oils or resins.

Particularly 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 whose end is blocked with the above polyester moiety, or conversely blocked with the above polyester or dimethylpolysiloxane), or with the above polyester as the main chain and (dimethyl)polysiloxane bonded to the side chain. At least one copolymer can be mentioned.

The amount of these simple addition type silicone oils may vary depending on the type, so it may not be possible to uniformly determine the amount. 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, and S-774-PL-3 [all photo-curing silicone oils manufactured by Shin-Etsu Chemical Co., Ltd.] manufactured] etc.

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. Antioxidants described in JP-A-1-127387 and the like, and compounds known to improve image durability in photographs and other image recording materials can be mentioned.

As the UV absorber and light stabilizer, JP-A-59-
No. 158287, No. 63-74686, No. 63-14
No. 5089, No. 59-196292, No. 62-229
No. 594, No. 63-122596, No. 61-2835
Examples include compounds described in No. 95, JP-A No. 1-204788, and 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 fluorocarbon resin particles, guanamine resin particles, acrylic resin particles, and silicone resin particles. These inorganic/organic resin particles vary depending on their specific gravity, or from 0.1 to 70% by weight.
It is preferable to add

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

Examples of the plasticizer include phthalate esters (e.g. dimethyl phthalate, dimethyl phthalate, dioctyl phthalate,
(didecyl phthalate, etc.), adipate esters (dioctyl adipate, methyl lauryl adipate, di-2-ethylhexyl adipate, ethyl lauryl adipate, etc.), other oleic acid esters, succinic acid esters, maleic acid esters, Cehatic acid esters, citric acid esters, epoxy stearic acid esters, phosphate esters such as triphenyl phosphate and tricresyl phosphate, and glycols such as ethyl phthalyl ethyl glycolate and butylphthalyl butyl glycolate. Examples include esters.

5 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.

■Formation of the image-receiving layer The image-receiving layer is prepared by, for example, dispersing or dissolving the components forming the image-receiving layer in a solvent to prepare a coating solution for the image-receiving layer, and applying this coating solution for the image-receiving layer to the surface of the base material. Drying coating methods,
By a lamination method, etc., in which a mixture having components forming the image receiving layer is melt-extruded and laminated on the surface of a base material,
It can be formed.

Solvents used in the above coating method include alcohols (e.g. methyl alcohol, ethyl alcohol, etc.), esters (e.g. ethyl acetate, isopropyl acetate, n-acetate
butyl), cellosolves (e.g. methyl cellosolve, ethyl cellosolve, etc.), ketones (e.g. methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc.), ethers (e.g. tetrahydrofuran, dioxane, etc.), chlorinated solvents (e.g. chloroform, trichlorethylene, etc.) etc.).

These can be used alone or in combination of two or more.

When employing the above lamination method, if the base material is a synthetic resin as described later, a coextrusion method may also be employed.

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

The thickness of the image receiving layer is generally 3 to 50 pm, preferably 5 to 50 pm.
It is about 15 meters long.

On the other hand, since the image-receiving layer is self-supporting, when the image-receiving layer itself is used to form an image-receiving sheet for thermal transfer recording, the thickness of the image-receiving layer is usually 60 to 200 ILm, preferably 90 to
It is about 150gm.

Substrate - This substrate can be, for example, paper, coated paper, synthetic paper (polypropylene, polystyrene or a composite of these laminated with paper), white polyethylene terephthalate base film, transparent polyethylene terephthalate base film, polyolefin coated paper. etc. can be suitably used.

The thickness of the base material is usually 50 to 500 pm, preferably 50 pm.
~: 1100h.

Other layers - An overcoat layer may be laminated on the surface of the image-receiving sheet for thermal transfer recording for the purpose of improving the storage stability of the image or preventing fusion with the ink sheet for thermal transfer recording. .

This layer is coated with gravure coating and wire bar coating.

It can be formed by a known coating method such as roll coating.

The thickness of this layer is typically 0.5-5 #Lm.

Further, a cushion layer may be provided between the base material and the image-receiving layer of the image-receiving sheet for thermal transfer recording in order to reduce noise and transfer and record an image corresponding to the image information with good reproducibility.

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

The thickness of the cushion layer is usually preferably 5 to 25 μm.

(n) Ink sheet for thermal transfer recording An ink sheet for thermal transfer recording basically has a structure in which ink layers are laminated on a support.This ink layer is not limited to a single layer, but may be composed of multiple layers. It's okay.

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

(2) Heat-diffusible dye This heat-diffusible dye is not particularly limited as long as it is heat-diffusible or sublimable.

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

As the cyan dye, JP-A-59-78895;
No. 59-227948, No. 60-24966, No. 6
No. 0-53563, No. 60-130735, No. 60-
No. 131292, No. 6G-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 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 andrainthiazole dyes.

Further, as the heat-diffusible dye, an azomethine dye obtained by a coupling reaction of a compound having an open-chain or closed-chain active methylene group with an oxidized product of a p-phenylenediamine derivative or an oxidized product of a p-aminophenol derivative; and phenol or naphthol derivatives or p-
Indoaniline dyes obtained by a coupling reaction of an oxidized product of a phenylenediamine derivative or an oxidized product of a p-aminophenol derivative can also be suitably used.

The heat-diffusible dye may be a yellow dye, a magenta dye, or a cyan dye, as long as the image to be formed is monochromatic.

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

The amount of the heat-diffusible dye used is usually 0.1 to 20 g, preferably 0.2 to 5 g per 1 m'' of support.

(2) Binder As the binder for the ink layer, it is possible to use resins known in the field of thermal transfer recording, but preferred are acetal resins and/or cellulose resins as described below.

First, as the acetal resin, there are various compounds depending on the degree of acetalization and the content of acetyl groups, and typical examples include polyvinyl acetoacetal and polyvinyl butyral.

Among acetal resins, a polymerization degree of 30 is preferable.
It is an acetal resin having a glass transition point (Tg) of 50 to 200°C, a degree of acetalization of 60 mol% or more, and an acetyl group of 10 mol% or less.

The product names of acetal resins that meet these conditions are KS-1, KS-5, KS8, BL-1, BL.
-2, BL-3, BL-3, BM-1, BM-2, BM
-5, BM-3, BH-3, and BX-1 (all manufactured by Block Chemical Co., Ltd.).

Examples of cellulose resins include nitrocellulose, ethylcellulose, hydroxyethylcellulose, ethylhydroxyethylcellulose, hydroxypropylcellulose, methylcellulose, cellulose acetate,
Examples include cellulose acetate.

Among these cellulose resins, nitrocellulose is particularly preferred.

Furthermore, among the nitrocelluloses, preferred for the purposes of the present invention are those with a nitrogen content of 10.7 to 12.2% and a degree of polymerization of 35 to 11O1, based on the test method of JIS K-6703. 1.0 to 6.2 seconds (measured at 25.0% solids) and 3 to 8 seconds (measured at 20.0% solids), respectively.
(measured at solid content of 12.2%), 1.5 to 500 seconds (measured at solid content of 12.2%), 1. ] ~5.2 seconds (measured at 30% solids content), 10
It is a nitrocellulose having a value of 0 to 140 cps (measured by dissolving 1.5 g of dry nitrocellulose in 100 cc of butyl acetate).

The product names of nitrocellulose that meet these conditions are HIGI/16, HIGI/8, and HIGI/4.
,HIGI/2,HIGl,)IIG2,HIO2,H
IG20. HI G60,) IIG120, H
IG500, LIGI/8. LIGI/4, LIGI
/2.5L-1, HIlooO, HI2000, Clear H1/4, Chip H1/2, etc. [all manufactured by Asahi Kasei Kogyo ■].

Next, in addition to the acetal resin and cellulose resin, binders conventionally known in the thermal transfer recording field include, for example, acrylic resin.

Examples include methacrylic resin, polyvinyl alcohol, polyvinyl formal, polyvinyl chloride, polyvinyl ether, polyvinylpyrrolidone, polystyrene, polystyrene copolymer, and ionomer resin.

These may be used alone or in combination of two or more.

Further, the weight ratio of the binder and the heat-diffusible dye in the heat-sensitive layer is preferably in the range of 1:10 to 10:1.

(2) Additives Various additives may be added to the ink layer as necessary.

Additives include fluororesins, surfactants, release compounds such as waxes, fillers such as fine metal powders, silica gel, carbon black, and fine resin powders, and hardening agents that can react with binder components (such as isocyanates and radiation active compounds such as acrylics and epoxies).

Furthermore, in order to promote transcription, for example, JP-A-59-1
Heat-melting substances such as wax and higher fatty acid esters described in No. 06997 and the like can be used.

The amount of additives to be added cannot be uniformly determined depending on the type of additive and the purpose of addition, or the amount of additives as a whole is usually in the range of 30% by weight or less based on the binder.

■Formation of the ink layer The ink layer is prepared by dispersing or dissolving the heat-diffusible dye, the binder, and any optional components added as necessary in a solvent to prepare a coating solution for forming the ink layer. It can be formed by applying a coating liquid onto a support and drying it.

Note that the above-mentioned binders do not have to be used by dissolving one or more kinds in a solvent, but may be dispersed in a latex form.

The above-mentioned solvents include water, alcohols (e.g. ethanol, propatool), cellosolves (e.g. ethyl acetate), aromatics (e.g. tonolenine, xylene, chlorobenzene, etc.), ketones (e.g. acetone, methyl ethyl ketone, etc.), and ethers. (eg, tetrahydrofuran, dioxane, etc.), chlorinated solvents (eg, chloroform, trichloroethylene, etc.).

These solvents may be used alone or in combination of two or more.

For the above-mentioned coating, commonly known surface sequential coating using a gravure roll, extrusion coating, wire bar coating, roll coating, etc. can be used.

The ink layer is formed on the support at a thickness of 0.2 to 10 pm, or even 0.
．． It is desirable to form the film with a thickness of 3 to 3 pm.

The ink layer may be a yellow ink layer containing a binder resin and a yellow dye, a magenta ink layer containing a binder resin and a magenta dye, and a cyan ink layer containing a binder resin and a cyan dye. Preferably, the structure is repeatedly formed on the support.

Furthermore, in addition to the three ink layers arranged along the planar direction, a black ink layer containing a black image forming substance may be interposed between any two layers adjacent in the planar direction.

In particular, with respect to the black ink layer, clear characters can be obtained by using a diffusion transfer type ink or a melt transfer type ink.

As a support, any support may be used as long as it has good dimensional stability and can withstand the heat of a heating source such as a heat-sensitive head during image recording. Heat-resistant plastic films such as thin paper, polyethylene terephthalate polyamide, polycarbonate, polysulfone, polyvinyl alcohol cellophane, and polystyrene are suitable.

The thickness of the support is usually preferably in the range of 2 to 1107z.

-Other Layers A subbing layer may be provided between the ink layer and the support in order to improve adhesion.

Furthermore, an anti-fusing layer may be provided on the heat-sensitive layer.

Its thickness is usually 0.01 to 5 gm, preferably 0.05
It is in the range of ~l#Lm.

If the thickness is less than 0.01 gm, the effect of preventing fusion will not be sufficiently exhibited, and if it exceeds 5 JLm, the diffusion of the thermally diffusible dye from the ink layer to the image receiving layer will be inhibited, resulting in insufficient image density. It is not preferable because it becomes difficult to obtain.

The anti-fusing layer is usually made of polyester, amide wax, solid wax such as Teflon powder, phosphate ester surfactant, silicone oil, silicone resin,
It can be formed from fluororesin or the like.

Further, the back surface of the support (the side opposite to the ink layer) may have an anti-sticking layer for the purpose of preventing the head from adhesion, sticking, or wrinkles on the support.

The thickness of this anti-sticking layer is preferably in the range of 0.1 to 17 zm.

Furthermore, by forming perforations on the ink sheet for thermal transfer recording, or by providing register marks for detecting the positions of areas with different hues, convenience in use can be improved.

(m) Image formation To perform image formation, the surface of the image-receiving layer of the image-receiving sheet for thermal transfer recording of the present invention and the surface of the ink layer of the ink sheet for thermal transfer recording are brought into contact with each other, and then,
Add thermal energy to this interface to the image quiz.

Then, the heat-diffusible dye in the ink sheet for thermal transfer recording vaporizes or sublimates in an amount corresponding to the applied thermal energy, and migrates to the image-receiving sheet for thermal transfer recording.
It is fixed on the image-receiving layer to form an image there.

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

Thermal energy can be applied from the image receiving sheet for thermal transfer recording, from the ink sheet for thermal transfer recording, or from both sides.

However, from the viewpoint of effective use of thermal energy, it is better to carry out the process from the side of the ink sheet for thermal transfer recording.

Also, it is used for the purpose of controlling thermal energy to express the gradation of light and shade in images, or promoting the diffusion of dyes into image-receiving sheets for thermal transfer recording to ensure the expression of continuous gradations in images. It is preferable to apply thermal energy from the side of the image-receiving sheet for thermal transfer recording.

Furthermore, in the sense that the advantages of the above two methods can be enjoyed at the same time, it is preferable to carry out the process from the side of the ink sheet for thermal transfer recording and the side of the image receiving sheet for thermal transfer recording.

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 using laser light as a heat source, the thermal energy provided can be changed by changing the amount of laser light and the irradiation area.

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 as a heat source, it is desirable that the ink sheet for thermal transfer recording and the image receiving sheet for thermal transfer recording be brought into close contact with each other, and that the surface irradiated with the laser beam absorbs the laser beam well. It is a good idea to color it black, for example.

When using an infrared flash lamp as a heat source, it is preferable to irradiate the lamp through a colored layer such as black, as in the case of using laser light.

In addition, irradiation with this lamp can be performed through a pattern or halftone dot pattern that continuously expresses the shading of an image such as black, and a colored layer such as black on the - side and a negative of the above pattern can be used. It can also be performed in combination with a negative pattern.

When thermal energy is applied in this way, an amount of dye corresponding to the amount of energy is thermally transferred from the ink sheet for thermal transfer recording to the image receiving layer of the image receiving sheet for thermal transfer recording.
A one-color image can be recorded there, but if the ink sheet for thermal transfer recording is replaced, a color photographic-like color image can also be obtained.

For example, if the thermal transfer recording ink sheets of yellow, red, lithium color, and black if necessary are sequentially replaced and thermal transfer is performed according to each color, it is possible to obtain a color photographic color image that is a combination of each color. .

Note that instead of using ink sheets for thermal transfer recording of each color as described above, the following method can also be used.

That is, a heat-sensitive transfer recording ink sheet is prepared which has areas painted in each color in advance, and the yellow area is used to thermally transfer the yellow separation image, and then the red area is used to thermally transfer the red separation image. The color image is exclusively thermally transferred, and thereafter, by sequentially repeating this operation, yellow, red, indigo, and, if necessary, black, color-separated images are thermally transferred.

This method has the advantage that it is not necessary to replace the ink sheet for thermal transfer recording.

[Example] Next, the present invention will be explained in more detail based on Examples.

Note that in the following, "parts" represent "parts by weight."

(Example 1) A coating liquid for forming a heat-sensitive layer having the following composition was applied to the corona-treated surface of a 9 part m thick polyethylene terephthalate film [trade name 5PET: manufactured by Toyobo & IM] as a support by a wire bar coating method. Thickness after drying Ig
Apply silicone oil [X-41,400
3A, manufactured by Shin-Etsu Silicone Co., Ltd.] was applied using a dropper and spread over the entire surface, and a back surface treatment coating was performed to obtain an ink sheet for thermal transfer recording.

Ink disperse dye: 4 parts [Kayaset Blue 136: manufactured by Nippon Kayaku ■] Polyvinyl butyral: 5 parts [degree of polymerization: 1,700, Product name B
X-1: Sekisui Chemical Co., Ltd.] Methyl ethyl ketone...90 parts Cyclohexanone...5 parts Next, synthetic paper with a thickness of 150 Bm (trade name Yubo FPG-150:
A coating solution for forming an image-receiving layer having the following composition was coated on the image-receiving layer (manufactured by Tamago Yuka Synthetic Paper Co., Ltd.) using a wire bar coating method, and then temporarily dried in a dryer, and then dried in an oven at a temperature of 100°C for 1 hour. An image-receiving sheet for thermal transfer recording was obtained by forming an image-receiving layer having a thickness of 5 parts m on synthetic paper.

Ionomer resin 4 parts [Resin (trade name Acrit 6416M A, manufactured by Taisei Kako ■) was dissolved in a mixed solvent of methyl ethyl ketone and toluene at a weight ratio of 1:1, and then phthalic anhydride was added. Carboxyl-modified polymer obtained by adding and further heating to convert into carboxyl groups] Amino-modified silicone oil... 0.2 parts [Product name KF-393: manufactured by Shin-Etsu Silicone] Epoxy-modified silicone oil.・・0.2 parts [Product name X-22-3
43: Made by Shin-Etsu Silicone ■] Vinyl chloride-vinyl acetate copolymer...10 parts [Product name VYHH: Made by Union Carbide] Methyl ethyl ketone...90
Part 2 - Butanol 20 parts Next,
The ink sheet for heat-sensitive transfer recording and the image-receiving sheet for heat-sensitive 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 a thermal head is used from the support side of the ink sheet for heat-sensitive transfer recording. output lW
Image recording was performed by heating under the following conditions: /dot, pulse width of 0.3 to 4.5 m5 ec, and dot density of 3 dots/mm.

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

The results are shown in Table 1.

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

0...OD value is 2.0 or more.

Δ・・・OD value 1.7~2.0° ×...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, and fluctuations in image density were observed.

○...When the concentration fluctuation is within 8%.

×: When the concentration fluctuation exceeds 8%.

(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.

Ionomer resin: 40 parts (same as Example 1) Polyester resin: 10 parts [Product name: Vylon 290: manufactured by Toyobo ■] Amino-modified silicone Oil... 0.2 parts [Product name KF: 19:l: manufactured by Shin-Etsu Silicone] Epoxy-modified silicone oil...
・0.2 parts [Product name X-22-343: Shin-Etsu Silicone ■ml! ]toluene··············
57 parts xylene 13 parts methyl ethyl ketone 6.3 parts 2-butanol 14 parts cyclohexanone 30 parts (Example 3) The same procedure was carried out as in Example 1 except that the composition of the coating liquid for forming the image receiving layer was changed to the following composition and the thickness of the image receiving layer was changed to 1107 t. It was carried out in the same manner as in Example 1.

The results are shown in Table 1.

Polycarbonate: 20 parts [Product name: Panlite K-1300: manufactured by Kijin Kasei ■] Ionomer resin: 50 parts (same as Example 1) Amino modified Silicone oil... 0.1 part [Product name KF393: manufactured by Shin-Etsu Silicone ■] Epoxy-modified silicone oil... [1.1 part [Product name X-22-]
343: Made by Shin-Etsu Silicone ■] Dioxane...
・・・・・・ 100 parts 2-butanol・・・・・・
...50 parts polyester modified silicone...
4 parts [Product name: It was carried out in the same manner as in Example 1.

The results are shown in Table 1.

(Comparative Example 2) Comparative Example 2 was carried out in the same manner as in Example 2, except that the use of the ionomer resin, which is one of the components of the coating liquid for forming an image-receiving layer, was omitted.

The results are shown in Table 1.

Table 1 [Effects of the Invention] The image-receiving sheet for thermal transfer recording of the present invention can prevent fusion with the ink sheet for thermal transfer recording during thermal transfer, and can obtain high-density images. Since the image exhibits good heat resistance after thermal transfer, a clear, high-quality image can be preserved for a long period of time.

[Brief explanation of drawings]

FIGS. 1A and 1B are cross-sectional views showing different image-receiving sheets for thermal transfer recording of the present invention. 1... Base material, 2... Image receiving layer, 2a... Image receiving layer.

Claims (3)

[Claims] (1) An image-receiving sheet for thermal transfer recording, characterized by having an image-receiving layer containing a binder resin and an ionomer resin. (2) The image-receiving sheet for thermal transfer recording according to claim 1, wherein the binder resin is selected from the group consisting of vinyl chloride resin, polyester, polycarbonate, and polyacrylic. (3) The image-receiving sheet for thermal transfer recording according to claim 1, wherein the image-receiving layer contains a release agent.