JPH10193812A - Thermal transfer image receiving sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a sufficiently dense clear image by containing a polyvinyl formal resin, a thermoplastic resin other than the polyvinyl formal resin and a mold-releasing agent in a dye receiving layer. SOLUTION: A thermal transfer image receiving sheet is made up of a base material sheet such as polyolefin synthetic paper, art paper, coated paper and cast coat paper, and a dye receiving layer provided on one side of the sheet. The dye receiving layer contains a polyvinyl alcohol resin or polyvinyl formal resin obtained by formalizing a hydroxyl group in a partially-saponified polyvinyl alcohol resin, a thermoplastic resin other than the polyvinyl formal resin, and a mold-releasing agent such as a liquid paraffin or wax. As a result, it is possible to obtain an image having a clear image density, excelling in light fastness, fusion resistance, and preservability.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal transfer image-receiving sheet, and more particularly, to a thermal transfer sheet capable of forming a recorded image having excellent durability such as color density, sharpness, and fastness, particularly light fastness and heat resistance. The present invention relates to an image receiving sheet.

[0002]

2. Description of the Related Art In recent years, the demand for full-color printers has been increasing year by year, and the recording methods of such full-color printers include an electrophotographic system, an ink-jet system, a thermal transfer system, and the like. For this reason, the thermal transfer method has been attracting attention.

In the thermal transfer method, a recording medium having a transfer layer in which a colorant is dispersed in a heat-fusible material is superimposed on an image receiving sheet, and heat is applied to the recording medium in an image-like manner to heat the transfer layer. A melt-type transfer recording, which is melted and transferred and recorded on an image receiving sheet, is superimposed on a recording medium having a transfer layer containing a heat sublimable dye or a heat transferable dye (hereinafter, simply referred to as a sublimable dye) and the image receiving sheet. Sublimation transfer recording in which the dye in the transfer layer is sublimated or transferred onto the image receiving sheet by applying heat to the recording medium in an image form. As a recording of a full-color image, a sublimation transfer recording is generally superior in view of the fidelity of color tone, and a high-quality image can be formed.

Conventionally, in sublimation transfer recording, various thermoplastic polyester-based resins have been used as image receiving sheets as dyeing resins which exhibit strong dyeability to sublimable dyes, have a high transfer speed, and have excellent storage stability. Formed on a substrate (paper, synthetic paper, synthetic resin film, etc.) comprising a dye receiving layer. For example, JP-A-57-10788
No. 5 discloses the use of a saturated polyester resin, and JP-A-61-3796 discloses a sulfonated phthalic acid-modified polyester resin, and JP-A-62-24.
No. 4696 proposes to use a phenyl-modified polyester resin. Also, JP-A-63-797
No. 1 proposes the use of a polyester resin comprising a polyol having a phenyl group and a dicarboxylic acid and having a molecular weight of 10,000 to 30,000.

However, the conventional image receiving sheet does not have sufficient releasability from the surface of the recording medium. In particular, when the image receiving sheet and the recording medium are overlapped, the former traveling speed is N times (N>) the latter traveling speed. So-called N to record in 1)
When applied to the double mode (velocity difference mode) recording method, a strong frictional force is applied between the two sheets, so that fusion may occur during recording or the sheets may be damaged.

When a polyester resin is used as the receiving layer resin, sufficient recording sensitivity cannot be obtained. In general, the recording speed of sublimation transfer recording is low. Therefore, in the case of high-speed recording, low recording sensitivity of the image receiving layer resin is a major obstacle. On the other hand, if the recording sensitivity is not sufficient, the applied voltage must be set high, which is not only unfavorable from the viewpoint of energy saving, but also causes conditions such as side effects such as fusing to easily occur, leading to poor printed images. .

[0007] Such various durability during recording is excellent.
Polyvinyl chloride and polyvinyl chloride-vinyl acetate copolymers have been widely used as thermoplastic resins having good dyeability and preservability. JP-A-64-5886 and JP-A-4-111 are known.
No. 3893 discloses polyvinyl chloride and JP-A-4-8.
No. 3,885, the use of polyvinyl chloride or polyvinyl chloride-vinyl acetate copolymer is proposed, and Japanese Patent Application Laid-Open No. 4-135794 proposes the use of polyvinyl chloride-vinyl acetate copolymer. In addition, Japanese Unexamined Patent Publication No.
JP-A-283595, JP-A-4-339692, and JP-A-7-195847 disclose that a saturated polyester resin and a vinyl chloride-vinyl acetate copolymer are used in combination.

However, these polyvinyl chlorides,
In the case of a vinyl chloride-vinyl acetate copolymer or the polyester resin,
There is a problem that the light fastness of the formed image is inferior to the dye image formed on the dye receiving layer composed of a polyvinyl butyral-based resin or a polycarbonate-based resin, and in consideration of high sensitivity and storage stability, these A dye receiving layer made of a dyeing resin is not sufficient.

As another means for improving the light fastness of an image, there is a method in which an ultraviolet absorber, a light stabilizer, an antioxidant and the like are contained in a dye receiving layer.
No. 1-32789, JP-A-61-229594, JP-A-63-145089, JP-A-1-127287,
JP-A-3-19893, JP-A-4-211995,
It is disclosed in Japanese Patent Application Laid-Open Nos. 5-139057 / 1993.

However, although the effect of improving the light resistance by adding an ultraviolet absorber and a light stabilizer can be seen, the amount of addition is limited due to side effects such as a change in the color tone of the image and fusing, and practical use of the additive alone is practical. We have not yet reached a satisfactory level. Further, cellulose ester-based resins and polycarbonate-based resins having relatively good light resistance also have problems such as generally poor adhesion to a base sheet. Therefore, there has been a demand for an image-receiving sheet having more excellent overall performance.

[0011]

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and in a thermal transfer method using a sublimable dye, the above-mentioned problems have been solved and a clear image having a sufficient density has been obtained. Further, it is an object of the present invention to provide a thermal transfer image-receiving sheet in which a formed image exhibits excellent fastness, particularly excellent light fastness.

[0012]

According to the present invention, first, in a thermal transfer image-receiving sheet having a dye-receiving layer formed on at least one surface of a base sheet, the dye-receiving layer is formed of at least a polyvinyl formal resin. There is provided a thermal transfer image-receiving sheet characterized by containing a release agent.
Second, in a thermal transfer image-receiving sheet having a dye-receiving layer formed on at least one surface of a substrate sheet, the dye-receiving layer contains at least polyvinyl formal resin, a thermoplastic resin other than polyvinyl formal resin, and a release agent. A heat transfer image receiving sheet is provided. Third, in a thermal transfer image-receiving sheet having a dye-receiving layer formed on at least one surface of a substrate sheet, the dye-receiving layer contains at least a curing reaction product of a polyvinyl formal resin and a crosslinking agent and a release agent. A heat transfer image receiving sheet is provided. Fourth, in a thermal transfer image-receiving sheet having a dye-receiving layer formed on at least one surface of a substrate sheet, the dye-receiving layer is at least a cured reactant represented by the following A, a cured reactant represented by the following B, and a mold release. The present invention provides a thermal transfer image receiving sheet characterized by containing an agent. A: Curing reaction product of polyvinyl formal resin and crosslinking agent B: Curing reaction product of thermoplastic resin other than polyvinyl formal resin and crosslinking agent Fifth, a dye receiving layer is formed on at least one surface of the base material sheet A thermal transfer image-receiving sheet is provided, wherein the dye-receiving layer contains at least a curing reactant represented by the following A, a thermoplastic resin represented by the following C, and a release agent. A: Curing reaction product of polyvinyl formal resin and crosslinking agent C: Thermoplastic resin other than polyvinyl formal resin
And those having no reactivity with a crosslinking agent. Sixth, in the thermal transfer image-receiving sheet according to any one of the above first to fifth, the Vicat softening temperature of the dye receiving layer is 70 to 200 ° C. A thermal transfer image receiving sheet is provided. Seventh, the thermal transfer image-receiving sheet according to any one of the second, fourth and fifth aspects, wherein the Vicat softening temperature of the thermoplastic resin other than the polyvinyl formal resin is 100 ° C. or lower. Is provided. Eighth, in the thermal transfer image-receiving sheet according to any one of the second, fourth, and fifth, the ratio of the thermoplastic resin other than the polyvinyl formal resin in the dye receiving layer is the total amount of the resin forming the dye receiving layer. The thermal transfer image-receiving sheet is provided in an amount of 5 to 50% by weight. Ninth, there is provided a thermal transfer image-receiving sheet according to any one of the third to fifth aspects, wherein the crosslinking agent is a polyfunctional isocyanate compound.

Hereinafter, the present invention will be described in detail. As described above, the present invention provides a thermal transfer image-receiving sheet having a dye-receiving layer formed on at least one surface of a substrate sheet, wherein the dye-receiving layer contains a polyvinyl formal resin and a release agent. It is. That is, by adopting such a configuration, it is possible to obtain a thermal transfer image-receiving sheet which provides a clear image having a sufficient density and has excellent robustness of the formed image, particularly, excellent fusion resistance, storage stability and light resistance. .

[0014] The above-mentioned polyvinyl formal resin is not only used alone, but it is possible to improve the thermal sensitivity by mixing with a thermoplastic resin other than the polyvinyl formal resin. In addition, a curing reaction product (A) of a polyvinyl formal resin and a crosslinking agent, or a curing reaction product (B) of a thermoplastic resin other than the polyvinyl formal resin and a crosslinking agent was further mixed with the curing reaction product (A). By using such a material, it is possible to improve the image quality and storability of an image to be formed. In addition, by mixing the curing reactant (A) with a thermoplastic resin other than the polyvinyl formal resin and having no reactivity with a crosslinking agent (C), excellent fusion resistance due to the curing reactant of the polyvinyl formal resin can be obtained. High thermal sensitivity can be simultaneously provided by a non-crosslinkable thermoplastic resin other than the polyvinyl formal resin.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in more detail with reference to the embodiments. The thermal transfer image-receiving sheet of the present invention comprises a base sheet and a dye receiving layer provided on at least one surface of the base sheet. Examples of the base sheet used in the present invention include synthetic paper (polyolefin-based, polystyrene-based, etc.), high-quality paper, art paper, coated paper, cast-coated paper, wallpaper, backing paper, synthetic resin, or emulsion-impregnated paper. , Synthetic rubber latex-impregnated paper, synthetic resin-coated paper, paperboard, etc., cellulose plastic paper, various plastic films such as polyolefin, polyvinyl chloride, polyethylene terephthalate, polystyrene, polymethacrylate, polycarbonate, etc. Further, a white opaque film formed by adding a white pigment or a filler to these synthetic resins, a foamed foamed sheet, or the like can be used, and is not particularly limited.

Also, a laminate formed by any combination of the above-mentioned base sheets can be used. Examples of typical laminates include synthetic paper of cellulose fiber paper and synthetic paper, or synthetic paper of cellulose fiber paper and plastic film or sheet.

The thickness of these base sheets may be arbitrary,
For example, a thickness of about 10 to 300 μm is common.
Further, when the substrate sheet as described above has a poor adhesion to the dye receiving layer formed on the surface thereof, it is preferable to apply a primer treatment or a corona discharge treatment to the surface.

A particularly preferred substrate sheet in the present invention is synthetic paper.
The one in which a dye receiving layer is provided directly or through an intermediate layer on synthetic paper is the most inexpensive and does not impair the sensitivity of the dye receiving layer. As another configuration, by forming the layer closest to the dye-receiving layer of the base sheet with foamed PET, a high-density and clear gradation image can be obtained during image recording. Further, it is more preferable to use a base sheet in which synthetic paper, transparent PET, and foamed PET are laminated in this order, whereby a thermal transfer image-receiving sheet excellent in recording density and curl resistance can be obtained.

The dye receiving layer formed on the surface of the base sheet is for receiving the sublimable dye transferred from the thermal transfer sheet and maintaining the formed image. The dye receiving layer which characterizes the present invention is formed by (1) a polyvinyl formal resin as a main component and a releasing agent. (2) Further, the other dye-receiving layer is formed mainly of a polyvinyl formal resin and a thermoplastic resin other than the polyvinyl formal resin, and containing these and a release agent.
(3) Still another dye receiving layer is formed mainly of a cured reaction product of a polyvinyl formal resin and a cross-linking agent, and is formed by containing these and a release agent. (4) Still another dye receiving layer is formed mainly of a curing reactant represented by the following A and a curing reactant represented by the following B, and containing these and a release agent. A: Curing reactant of polyvinyl formal resin and cross-linking agent B: Curing reactant of thermoplastic resin other than polyvinyl formal resin and cross-linking agent It is formed by using a curing reactant represented by the following C as a main component and a release agent. A: Curing reaction product of polyvinyl formal resin and crosslinking agent C: Thermoplastic resin other than polyvinyl formal resin
And have no reactivity with the crosslinking agent

Each of the dye receiving layers (1) to (5), which are formed mainly of a polyvinyl formal resin, is made of Vi
It is preferable that the cat softening temperature is 70 to 200 ° C. That is, when the Vicat softening temperature is extremely low, less than 70 ° C., the heat resistance of the dye-receiving layer itself is reduced, which is likely to cause side effects during image formation and deteriorate image quality storage after image formation. On the other hand, V of the dye receiving layer
When the icat softening temperature is higher than 200 ° C., the heat resistance is increased and the sensitivity at the time of image formation is reduced. Further, the solubility in a solvent is deteriorated, and the viscosity of the dye-receiving layer forming liquid is increased. This is not desirable because coating unevenness is likely to occur at the time, and even if the resin concentration is lowered to lower the solution viscosity, a coating problem such as a predetermined film thickness cannot be obtained. The measurement of the softening temperature of the thermoplastic resin was performed under the following conditions in accordance with JIS-K7169. Measuring device: TMA manufactured by TA Instrumenta
2940 type Measurement mode: Penetration mode Needle diameter: 1 mm Load: 0.49 N Specimen dimensions: 5 × 5 mm square Temperature rise rate: 5 ° C./min Temperature range: room temperature to 250 ° C. (350 ° C.) Measurement atmosphere: nitrogen gas Inflow (flow rate: 100 ml / min)

In the present invention, the polyvinyl formal resin is obtained by formalizing hydroxyl groups in a polyvinyl alcohol resin or a partially saponified polyvinyl alcohol resin, and those having various ratios of formalization degree can be used.

The degree of formalization in the polyvinyl formal resin is preferably at least 70 mol%, and if the composition ratio is less than the above range, the solubility in an organic solvent is reduced, which hinders the preparation of a dye-receiving layer forming solution. This is not preferred.

The degree of polymerization of the polyvinyl formal resin is not particularly limited, but is preferably 1500 or less in average degree of polymerization. When the average polymerization degree is as high as 1500 or more, the heat resistance of the resin itself is increased, so that the sensitivity at the time of image formation is reduced. Further, the solubility in a solvent is deteriorated, and the viscosity of the dye-receiving layer forming liquid is also increased. It is not desirable because coating unevenness is likely to occur during coating, and even if the resin concentration is lowered to lower the solution viscosity, a coating problem such as a predetermined film thickness cannot be obtained.

The thermoplastic resin other than the polyvinyl formal resin used in the dye receiving layer of the present invention includes vinyl acetate resin, polyester resin, polyvinyl chloride resin, vinyl chloride / vinyl acetate copolymer, cellulose ester resin, epoxy resin, Polyvinyl butyral resin, polyvinyl acetal resin, polyurethane resin, polyacrylate resin, polymethacrylate resin, polycarbonate resin, polyvinyl alcohol resin, polystyrene resin,
Known materials such as polyetherimide resin, polyamide resin, polyethylene oxide resin, polyvinyl ether resin, and polyacrylonitrile resin can be used.

Vi of thermoplastic resin other than polyvinyl formal resin used by mixing with polyvinyl formal resin
The cat softening temperature is particularly preferably 100 ° C. or lower, and higher sensitivity can be obtained than in the case of using polyvinyl formal alone. If the Vicat softening temperature of the thermoplastic resin other than polyvinyl formal is 100 ° C. or higher, the effect of increasing the sensitivity at the time of image recording is undesirably reduced.

The amount by weight of the thermoplastic resin other than the polyvinyl formal resin relative to the total weight of the resin forming the dye-receiving layer is preferably 5 to 50% by weight. Heat resistance and light resistance of the entire layer may be deteriorated, and therefore, should be avoided.

In the present invention, a release agent added as a constituent material of the dye receiving layer together with the polyvinyl formal resin is used to enhance the releasability of the dye receiving layer. Examples of the release agent include petroleum-based lubricating oils such as liquid paraffin, hydrogen halide, diester oil, silicone oil, fluorosilicone oil, modified (epoxy-modified, amino-modified,
Alkyl-modified, polyether-modified, etc.) Synthetic lubricating oils such as silicone oils, silicone lubricating substances such as copolymers of organic compounds such as polyoxyalkylene glycol and silicone, various fluorine-based surfactants such as fluoroalkyl compounds, Waxes such as paraffin wax and polyethylene wax, higher fatty acids, higher aliphatic alcohols,
Examples include higher aliphatic amides, higher fatty acid esters, higher fatty acid salts and the like.

The release effect can be effectively exhibited by adding 5% by weight of these release agents to the dye receiving layer. However, it must be less than 30% by weight.

Next, as the curing agent used in the present invention,
Known curing agents can be used, and examples thereof include isocyanates and dialdehyde compounds. Further, generally, various kinds of crosslinkable resins which react with secondary hydroxyl groups may be used at the time of the curing reaction to control the molecular weight and the thermal characteristics. Examples of the crosslinkable resin include a phenolic resin, an epoxy resin, and a melamine resin, and these may be used alone or as a mixture of two or more. When a resin having active hydrogen typified by the polyvinyl formal resin of the present invention is selected as the resin capable of dyeing the sublimable dye, it is appropriate to use an isocyanate compound.

As the isocyanate compound, a polyfunctional di- or tri-isocyanate compound is particularly effective. For example, 2,4-tolylene diisocyanate,
2,6-tolylene diisocyanate, hydrogenated 4,4-diphenylmethane diisocyanate, lysine diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, tetramethyl xylene diisocyanate, lysine ester triisocyanate, 1,6,11
-Undecane triisocyanate, 1,8-diisocyanate-4-isocyanatomethyloctane, 1,3
6-Hexamethylene triisocyanate bicycloheptane triisocyanate, triphenylmethane triisocyanate, isophorone diisocyanate, bis isocyanate methyl cyclohexane, trimethyl hexamethylene diisocyanate, and modified or derivatives thereof.

The amount of the crosslinking agent to be added is suitably an amount satisfying the relationship of [total number of isocyanate groups in the crosslinking agent] / [total number of hydroxyl groups in the polyvinyl formal resin] = 0.1 to 1.5. It is not preferable to add in excess of this relationship because unreacted isocyanate compound may deteriorate light resistance.

In order to obtain the polymer thermal characteristics of the present invention by reacting a polyvinyl formal resin or a thermoplastic resin other than polyvinyl formal resin with an isocyanate compound, it cannot be obtained only by coating and drying the dye-receiving layer. It can be obtained for the first time by carrying out aging treatment after standing for a long time in a high-temperature atmosphere as a post-treatment. In addition, aging in a high-temperature atmosphere for a long time is disadvantageous in terms of manufacturing cost. Therefore, the conditions for high-temperature aging can be relaxed by adding a curing catalyst to the dye-receiving layer forming liquid.

For the purpose of improving the light resistance, an aliphatic isocyanate compound or a non-yellowing type isocyanate compound is more effective for selecting a curing agent. In this case, the curing reaction rate is higher than that of an aromatic isocyanate compound. In general, it is desirable to use a curing catalyst in combination, since it is generally slower than other isocyanate compounds of the fast-curing type.

As such a curing catalyst, an acid or a metal compound is effective, and it is preferable to use an organotin catalyst for the reaction between a resin having active hydrogen and an isocyanate compound. The organotin catalyst is a compound in which at least a carbon atom is directly bonded to a tetravalent tin atom, and is represented by the following general formula.

[0035]

R _a SnY _4-a (where R is an alkyl group, Y is an organic acid salt, and a is an integer of 1 to 4)

As the organotin-based catalyst, dioctyltin-based catalyst having relatively low toxicity is preferred. Examples of the organotin-based catalyst include dibutyltin oxide, dioctyltin oxide, tetrabutyltin, tin tetrachloride, dibutyltin laurate, dibutyltin dilaurate, dioctyltin dilaurate, butyltin trichloride, dibutyltin diacetate, and the like. The amount of the catalyst added is preferably 0.05 to 1.3% by weight in the image receiving layer. If the amount is too small, the effect of promoting the curing is low and sufficient heat resistance cannot be obtained. If the amount is too large, the light resistance is adversely affected.

In the present invention, an ultraviolet absorber can be used in the dye receiving layer in order to increase the light fastness of the image. Known compounds such as benzophenone-based, benzotriazole-based, cyanoacrylate-based, salicylate-based and oxalic anilide-based compounds can be used as the ultraviolet absorber, and known compounds such as hindered amine-based compounds can be used as the light stabilizer. When using an ultraviolet absorber and / or a light stabilizer, their melting points are preferably 60 ° C. or higher. If the melting point is less than 60 ° C., it is not preferable because fusing occurs at the time of image recording and the density unevenness of the image quality becomes remarkable. In general, in the case of a low-molecular type, a high-molecular type is more preferable because the ultraviolet absorber easily migrates to the surface of the dye-receiving layer and may cause problems such as blocking and bleed-out.

As the polymer type ultraviolet absorber, known ones can be used. For example, [2-hydroxy-4
-(Methacryloyloxyethoxy) benzophenone]-
Methyl methacrylate copolymer, [2-hydroxy-4-
(Methacryloyloxymethoxy) benzophenone] -methyl methacrylate copolymer, [2-hydroxy-4- (methacryloyloxyoctoxy) benzophenone] -methyl methacrylate copolymer, [2-hydroxy-4- (methacryloyloxidedecyloxy) ) Benzophenone] -methyl methacrylate copolymer, [2-hydroxy-4- (methacryloyloxybenzyloxy) benzophenone] -methyl methacrylate copolymer, [2,2′-dihydroxy-
4- (methacryloyloxyethoxy) benzophenone]
-Methyl methacrylate copolymer, [2,2'-dihydroxy-4- (methacryloyloxymethoxy) benzophenone] -methyl methacrylate copolymer, [2,2'-dihydroxy-4- (methacryloyloxyoctoxy) benzophenone ] -Methyl methacrylate copolymer, [2,2'-
Dihydroxy-4- (methacryloyloxybenzyloxy) benzophenone] -methyl methacrylate copolymer,
[2,2-dihydroxy-4- (methacryloyloxidedecyloxy) benzophenone] -methyl methacrylate copolymer, [2,2 ′, 4-trihydroxy-4 ′-(methacryloyloxyethoxy) benzophenone] -methyl methacrylate Copolymer, [2,2 ', 4-trihydroxy-4'
-(Methacryloyloxymethoxy) benzophenone]-
Methyl methacrylate copolymer, [2,2 ′, 4-trihydroxy-4 ′-(methacryloyloxyoctoxy) benzophenone] -methyl methacrylate copolymer,
2 ', 4-trihydroxy-4'-(methacryloyloxidedecyloxy) benzophenone] -methyl methacrylate copolymer, [2,2 ', 4-trihydroxy-4'-(methacryloyloxybenzyloxy) benzophenone]- Methyl methacrylate copolymer, [4-hydroxy-4 '-(methacryloyloxyethoxy) benzophenone] -methyl methacrylate copolymer, [4-hydroxy-4'-(methacryloyloxymethoxy) benzophenone] -methyl methacrylate Polymer, [4-hydroxy-4 ′-(methacryloyloxyoctoxy) benzophenone] -methyl methacrylate copolymer, [4-hydroxy-4 ′-(methacryloyl oxidedecyloxy) benzophenone] -methyl methacrylate copolymer, [4-hydroxy-4 ′-(methacryloyloxybenzyloxy) benne Phenone] - methyl methacrylate copolymer, [2-hydroxy-4'-methyl-4- (methacryloyloxy ethoxy) benzophenone] - methyl methacrylate copolymer, [2-hydroxy -
4'-methyl-4- (methacryloyloxymethoxy) benzophenone] -methyl methacrylate copolymer, [2-hydroxy-4'-methyl-4- (methacryloyloxyoctoxy) benzophenone] -methyl methacrylate copolymer, [2-hydroxy-4′-methyl-4- (methacryloyloxidedecyloxy) benzophenone] -methyl methacrylate copolymer, [2-hydroxy-4′-methyl-4
-(Methacryloyloxybenzyloxy) benzophenone] -methyl methacrylate copolymer, [2- (2'-hydroxy-4'-methacryloyloxyethoxy) benzotriazole] -methyl methacrylate copolymer, [2- (2 ' −
(Hydroxy-4′-methacryloyloxyethoxy) -5
-Chlorobenzotriazole] -methyl methacrylate copolymer.

Further, known additives such as a surfactant, an ultraviolet absorber, an antioxidant, and a fluorescent whitening agent can be added to the dye receiving layer.
It must be 0% by weight or less.

The thermal transfer image-receiving sheet of the present invention is characterized in that at least one surface of the above-mentioned base sheet is provided on at least one surface of the above-mentioned polyvinyl formal resin or a thermoplastic resin other than the polyvinyl formal resin and the polyvinyl formal resin, a releasing agent, Other additives, for example, a cross-linking agent, a catalyst, an ultraviolet absorber, an antioxidant, a solution obtained by adding a light stabilizer and the like are dissolved in an appropriate organic solvent, or a dispersion obtained by dispersing in an organic solvent or water, for example, It is obtained by applying and drying by a forming means such as a gravure printing method, a screen printing method and a reverse roll coating method using a gravure plate to form a dye receiving layer.

In the formation of the dye receiving layer, titanium oxide, zinc oxide, kaolin clay, calcium carbonate, fine powder silica, etc. are used for the purpose of improving the whiteness of the dye receiving layer to further enhance the sharpness of the transferred image. Addition of pigments and fillers is soft. The dye-receiving layer formed as described above may have any thickness, but generally has a thickness of 1 to 20 μm. Further, such a dye receiving layer is preferably a continuous coating, but may be formed as a discontinuous coating using a resin emulsion or a resin dispersion.

As a transfer medium of the sublimation type thermal transfer method using the thermal transfer image-receiving sheet of the present invention, a commercially available thermal sublimation transfer medium can be adequately applied, and an image having a clear image density and excellent fastness can be obtained. However, a more preferable transfer medium will be described below.

The sublimable dye is a dye that sublimates or vaporizes at 60 ° C. or higher, and may be any dye used in thermal transfer printing, such as a disperse dye or an oil-soluble dye. I. Disperse Yellow 1, 3, 8, 9, 1
6, 41, 54, 60, 77, 116 and the like. I. 1, 4, 6, 11, 15, 17, 5 of Disperse Red
5, 59, 60, 73, 83, C.I. I. Disperse Blue 3, 14, 19, 26, 56, 60, 64,
C. 72, 99, 108, etc. I. Solvent Yellow 77, 116, C.I. I. Solvent Red 23,
C. 25, 27, etc. I. Solvent Blue 36, 6
3, 83, 105 and the like. These dyes can be used singly, but can be used by mixing several kinds.

As the binder used in the ink layer, a thermoplastic or thermosetting resin is used. For example, vinyl chloride resin, vinyl acetate resin, polyamide, polyethylene, polycarbonate, polystyrene, polypropylene, acrylic resin, phenol resin , Polyester, polyurethane, epoxy resin, silicone resin, fluorine resin, butyral resin, melamine resin, natural rubber, synthetic rubber, polyvinyl alcohol, cellulose resin and the like. These resins can be used alone, but you can mix
Further, these copolymers may be used.

The thickness of the ink layer is preferably 0.5 to 20 μm, and particularly preferably 1 to 10 μm from the viewpoint of heat sensitivity. Also,
Further, the dye concentration is preferably from 5 to 80%, more preferably from 50 to 80% from the viewpoint of heat sensitivity and storage stability of the recording sheet.

The ink layer structure of the multi-purpose thermal transfer member (recording sheet) may include a dye transfer contributing layer between a dye supply layer and a low-dyeing resin layer as described in JP-A-5-64980. It is preferable to provide a dye supply containing at least an undissolved particulate sublimable dye in order to stably supply the dye for a long time and maintain good printing characteristics. It is preferred to provide a layer. Here, the undissolved particles are the ink at the time of forming the ink layer.
After drying (organic binder + sublimable dye + solvent), it means a dye that cannot be completely dissolved in the organic binder and precipitates as particles. Are different. The presence or absence of the undissolved particulate dye can be easily identified by an electron microscope after forming the dye supply layer. The particle size of the undissolved particulate dye varies depending on the thickness of the dye supply layer, but is 0.01 μm to 20 μm, preferably 1.0 μm.
m to 5 μm.

The dye supply layer and the dye transfer contributing layer were formed as a single layer on the substrate with the same amount of adhesion in each of the formulations, and each of the layers was superimposed on a separate image receiving layer. Is applied, the amount of dye transferred to each image receiving layer is desirably in the relationship of dye supply layer> dye transfer contributing layer. Diffusion of the dye in the ink layer follows Fick's law, and the amount dn of the dye passing through the cross-sectional area q in a unit time is expressed by the following equation.

[0048]

Dn = −D · (dc / dx) · q · dt dn: Amount of dye passing through cross-sectional area q per unit time q: Cross-sectional area D: Each part in the ink layer when heat is applied Average diffusion coefficient dc / dx: concentration gradient of dye in diffusion direction

Therefore, means for facilitating the diffusion and supply of the sublimable dye from the dye supply layer to the dye transfer contributing layer are as follows: (1) With regard to the dye concentration, the relation of (dye supply layer> dye transfer contributing layer) must be satisfied. And / or (2) with respect to the diffusion coefficient in each layer, the dye supply layer>
It is considered that the relationship of the dye transfer contributing layer is satisfied.

The thickness of the dye transfer contributing layer and the low-dyeing resin layer is generally 0.05 to 5 μm, preferably 0.1 to 5 μm.
2 μm. The thickness of the dye supply layer is generally 0.1 to 20 μm, preferably 0.5 to 10 μm. Known sublimable dyes, binders, and the like used in the dye supply layer and the dye transfer contributing layer can be used.

When a difference is made between the dye transfer contributing layer and the dye supply layer with respect to the glass transition point or the softening temperature, a resin having a glass transition point of 0 ° C. or less or a softening temperature of 60 ° C. or less, or a natural or synthetic rubber is used. Preferably, specifically,
Polyethylene oxide (Alcox E-30, 4
5, R-150, 400, 1000: manufactured by Meisei Chemical Co., Ltd.), caprolactone polyol (Placcel H-1,
4, 7 Daicel Chemical Industries, Ltd.) and the like are practically useful, and it is preferable to use the above-mentioned thermoplastic or thermosetting resin in combination with one or several of the above.

The dye concentration of the dye transfer contributing layer and the low-dyeing resin layer is usually about 0 to 80%, preferably about 10 to 60%. The dye concentration of the dye supply layer is 5 to 8
A dye concentration of 0% is preferable, but when a dye concentration gradient is provided between the dye transfer contributing layer and the dye supply layer, the dye concentration is 1.1 to 5 times, preferably 1.5 times, the dye concentration of the dye transfer contributing layer.
~ 3 times is desirable.

The dye state in the dye transfer contributing layer and the low dyeing resin layer is such that it is dispersed in a monomolecular state which actually contributes to the transfer to prevent the occurrence of transfer density unevenness, the dye supply layer and the dye transfer contributing layer. It is desirable to stably maintain the dye concentration gradient between the two.

Each ink layer may contain known additives such as a lubricant, a curing agent, a dispersant, and an antioxidant.

As the base sheet, a film such as a condenser paper, a polyester film, a polystyrene film, a polysulfone film, a polyimide film, or a polyaramid film is used, and a conventional sheet is provided between the base sheet and the dye supply layer, if necessary. An adhesive layer or the like may be provided, and a conventional heat-resistant lubricating layer may be provided on the back surface of the base sheet, if necessary.

Although an example in which the dye layer is divided into three layers has been described so far, the dye layer can be formed into a multilayer of three or more layers if an appropriate difference in the amount of dye transfer is generated and the function can be separated. .

In the above description, the recording method using a thermal head and a heat roller has been described. However, the recording sheet can be recorded by a method other than the thermal head and the heat roller, for example, a thermal printing plate, a laser plate. It can also be used for a method using light or Joule heat generated in a medium such as a support. Of these, the energetic thermal transfer method using Joule heat generated in a recording sheet is best known, for example, US Pat. No. 4,103,066,
No. 14060, JP-A-57-11080, and JP-A-59-9096.

When used in the energization transfer method, a resin such as polyester, polycarbonate, triacetylose, nylon, polyimide, aromatic polyamide and the like having relatively high heat resistance is used as a substrate, and aluminum, copper, iron, tin,
Metal powders such as zinc, nickel, molybdenum, silver and / or conductive powders such as carbon black are dispersed to adjust the resistance to a value between an insulator and a good conductor. A support on which a conductive metal is deposited or sputtered may be used. The thickness of these supports is 2 to 2 in consideration of Joule heat conduction efficiency.
It is desirable to be about 15 μm.

When the recording method is used for the laser beam transfer method, a material that absorbs laser light and generates heat may be selected as the substrate. For example, a conventional heat transfer film containing a light absorption conversion agent such as carbon or an absorption layer formed on the front and back surfaces of a support is used.

[0060]

The present invention will be described more specifically with reference to examples and comparative examples, but the present invention is not limited to the following examples. In the following description, “parts” or “%” is based on weight unless otherwise specified.

Example 1 <Dye-receiving layer forming solution 1> Polyvinyl formal resin (Vinilec H, manufactured by Chisso) 9.38 parts Toluene 40 parts Tetrahydrofuran 138 parts Alcohol-modified silicone oil (trade name SF841I manufactured by Toray Silicone Co., Ltd.) 0.62 parts Unmodified silicone oil (product name: SH200, kinematic viscosity: 1000 cs, manufactured by Toray Silicone Co., Ltd.) 0.62 part After drying at 0 ° C. to form a dye receiving layer having a thickness of 3 μm, this was subjected to a heat treatment at 100 ° C. for 1 hour to prepare a thermal transfer image receiving sheet.

Example 2 A thermal transfer image-receiving sheet was prepared in the same manner as in Example 1 except that Dye Receptive Layer Forming Solution 2 having the following composition was used in place of Dye Receptive Layer Forming Solution 1. <Dye receiving layer forming liquid 2> Polyvinyl formal resin (manufactured by Chisso Corporation: Vinylek E) 9.38 parts Toluene 40 parts Tetrahydrofuran 138 parts Alcohol-modified silicone oil (trade name SF8411 manufactured by Toray Silicone Co.) 0.62 parts Unmodified 0.62 parts of silicone oil (trade name: SH200, kinematic viscosity: 1000 cs, manufactured by Toray Silicone Co., Ltd.)

Example 3 A thermal transfer image-receiving sheet was prepared in the same manner as in Example 1 except that Dye Receptive Layer Forming Solution 3 having the following composition was used in place of Dye Receptive Layer Forming Solution 1 of Example 1. <Dye receiving layer forming liquid 3> Polyvinyl formal resin (manufactured by Denki Kagaku Kogyo Co., Ltd .: # 200) 6.6 parts Polycarbonate resin (LEXAN SP1210 manufactured by GE Plastics Japan) 2.8 parts Toluene 21.4 parts Tetrahydrofuran 122.0 Part: alcohol-modified silicone oil (trade name: SF8427, manufactured by Toray Silicone Co.) 0.62 part: unmodified silicone oil (trade name: SH200, dynamic viscosity: 1000 cs, manufactured by Toray Silicone Co.) 0.62 part

Example 4 A thermal transfer image-receiving sheet was prepared in the same manner as in Example 1 except that Dye Receptive Layer Forming Solution 4 having the following composition was used instead of Dye Receptive Layer Forming Solution 1. <Dye-receiving layer forming liquid 4> Polyvinyl formal resin (manufactured by Denki Kagaku Kogyo Co., Ltd .: # 100) 7.5 parts Vinyl acetate resin (Nippon Synthetic Chemical Industry Co., Ltd .: PV-500) 1.9 parts Toluene 21.4 Part Tetrahydrofuran 64.3 parts Alcohol-modified silicone oil (trade name: SF8427, manufactured by Toray Silicone Co.) 0.62 parts Unmodified silicone oil (trade name: SH200, manufactured by Tore Silicone Co., Ltd., kinematic viscosity: 1000 cs) 0.62 parts

Example 5 A thermal transfer image-receiving sheet was prepared in the same manner as in Example 1 except that Dye Receptive Layer Forming Solution 5 having the following composition was used in place of Dye Receptive Layer Forming Solution 1. <Dye-receiving layer forming liquid 5> Polyvinyl formal resin (manufactured by Chisso Corporation: Vinylek L) 4.0 parts Vinyl acetate resin (manufactured by Nippon Synthetic Chemical Industry Co., Ltd .: PV-500) 1.0 part Toluene 21.4 parts Tetrahydrofuran 64. 3 parts Alcohol-modified silicone oil (trade name: SF8427, manufactured by Toray Silicone Co.) 0.62 parts Unmodified silicone oil (trade name: SH200, manufactured by Toray Silicone Co., Ltd., kinematic viscosity: 1000 cs) 0.62 parts

Example 6 A thermal transfer image-receiving sheet was prepared in the same manner as in Example 1 except that Dye Receptive Layer Forming Solution 6 having the following composition was used in place of Dye Receptive Layer Forming Solution 1. <Dye-receiving layer forming liquid 6> Polyvinyl formal resin (manufactured by Chisso Corporation: Vinylek 8E) 4.0 parts PVC / vinyl acetate copolymer resin (manufactured by Sekisui Chemical Co., Ltd .: ESREC CN) 1.0 part Toluene 21.4 parts Tetrahydrofuran 64.3 parts Alcohol-modified silicone oil (trade name: SF8427, manufactured by Toray Silicone Co.) 0.62 parts Unmodified silicone oil (trade name: SH200, manufactured by Toray Silicone Co., Ltd., kinematic viscosity: 1000 cs) 0.62 parts

Example 7 A thermal transfer image-receiving sheet was prepared in the same manner as in Example 1 except that Dye Receptive Layer Forming Solution 7 having the following composition was used in place of Dye Receptive Layer Forming Solution 1 of Example 1. <Dye receiving layer forming liquid 7> Polyvinyl formal resin (manufactured by Chisso Corporation: Vinylek H) 7.5 parts Vinyl acetate resin (manufactured by Nippon Synthetic Chemical Industry Co., Ltd .: PV-500) 1.9 parts Toluene 21.4 parts Tetrahydrofuran 64. 3 parts 2 (2'-hydroxy-5'-methylphenyl) benzotriazole 0.5 parts Alcohol-modified silicone oil (trade name: SF8427, manufactured by Toray Silicone Co.) 0.62 parts Unmodified silicone oil (trade name: SH200, manufactured by Toray Silicone Co., Ltd.) Kinematic viscosity 1000cs) 0.62 parts

Example 8 A thermal transfer image-receiving sheet was prepared in the same manner as in Example 1 except that the dye-receiving layer forming liquid 8 having the following composition was used instead of the dye-receiving layer forming liquid 1 of Example 1. <Dye-receiving layer forming liquid 8> 7.5 parts of polyvinyl formal resin (manufactured by Chisso Corporation: Vinylex L) 1.9 parts of vinyl acetate resin (manufactured by Nippon Synthetic Chemical Industry Co., Ltd .: PV-500) 21.4 parts of toluene 21.4 parts of tetrahydrofuran 3 parts [2-hydroxy-4- (methacryloyloxyethoxy) benzophenone] -methyl methacrylate copolymer (trade name: UVA633L, manufactured by BASF) 0.88 parts alcohol-modified silicone oil (trade name: SF8427, manufactured by Toray Silicone Co.) 62 parts Unmodified silicone oil (trade name: SH200, kinematic viscosity: 1000 cs, manufactured by Toray Silicone Co., Ltd.) 0.62 parts

Example 9 A thermal transfer image-receiving sheet was prepared in the same manner as in Example 1 except that Dye Receptive Layer Forming Solution 9 having the following composition was used in place of Dye Receptive Layer Forming Solution 1. <Dye-receiving layer forming liquid 9> Polyvinyl formal resin (manufactured by Chisso: Vinylek E) 7.5 parts PVC / vinyl acetate copolymer (manufactured by Sekisui Chemical Co., Ltd .: Esrec CN) 1.9 parts Toluene 21.4 parts Tetrahydrofuran 64.3 parts [2-hydroxy-4- (methacryloyloxyethoxy) benzophenone] -methyl methacrylate copolymer (trade name: UVA635L, manufactured by BASF) 0.88 part Alcohol-modified silicone oil (trade name: SF8427, manufactured by Toray Silicone Co., Ltd.) 0.62 parts Unmodified silicone oil (trade name: SH200, kinematic viscosity: 1000 cs, manufactured by Toray Silicone Co., Ltd.) 0.62 parts

Example 10 A thermal transfer image-receiving sheet was produced in the same manner as in Example 1 except that the dye-receiving layer forming liquid 10 of the following composition was used instead of the dye-receiving layer forming liquid 1 of Example 1. <Dye receiving layer forming liquid 10> Polyvinyl formal resin (manufactured by Denki Kagaku Kogyo Co., Ltd .: # 100) 7.5 parts PVC / vinyl acetate copolymer (manufactured by Sekisui Chemical Co., Ltd .: Eslec CN) 1.9 parts Toluene 21.4 Part Tetrahydrofuran 64.3 parts [2-hydroxy-4- (methacryloyloxyethoxy) bensophenone] -methyl methacrylate copolymer (trade name UVA635L manufactured by BASF) 0.88 part Isocyanate compound (trade name D103H manufactured by Takeda Pharmaceutical Co., Ltd.) 2.60 parts Tin catalyst (trade name TK-1L, manufactured by Takeda Pharmaceutical Co., Ltd.) 0.60 parts Alcohol-modified silicone oil (trade name, SF8427, manufactured by Toray Silicone Co.) 0.62 parts Unmodified silicone oil (trade name, manufactured by Toray Silicone Co., Ltd.) Name SH200 kinematic viscosity 1000cs) 0.62 parts

Example 11 A thermal transfer image-receiving sheet was produced in the same manner as in Example 1 except that the dye-receiving layer forming solution 1 having the following composition was used in place of the dye-receiving layer forming solution 1 of Example 1. <Dye-receiving layer forming liquid 11> Polyvinyl formal resin (manufactured by Denki Kagaku Kogyo Co., Ltd .: # 200) 7.5 parts PVC / vinyl acetate copolymer (Sekisui Chemical Co., Ltd .: Eslec CN) 1.9 parts Toluene 21.4 Part Tetrahydrofuran 64.3 parts [2-hydroxy-4- (methacryloyloxyethoxy) benzophenone] -methyl methacrylate copolymer (trade name UVA633L manufactured by BASF) 0.88 part Isocyanate compound (trade name D140N manufactured by Takeda Pharmaceutical Co., Ltd.) 2.60 parts Tin catalyst (trade name TK-1L, manufactured by Takeda Pharmaceutical Co., Ltd.) 0.60 parts Alcohol-modified silicone oil (trade name, SF8427, manufactured by Toray Silicone Co.) 0.62 parts Unmodified silicone oil (trade name, manufactured by Toray Silicone Co., Ltd.) Name SH200 kinematic viscosity 1000 cs) 0.62 parts

Example 12 A thermal transfer image-receiving sheet was prepared in the same manner as in Example 1 except that the dye-receiving layer forming liquid 11 having the following composition was used in place of the dye-receiving layer forming liquid 1 of Example 1. <Dye receiving layer forming solution 12> Polyvinyl formal resin (manufactured by Chisso Corporation: Vinylek E) 4.0 parts PVC / vinyl acetate copolymer (manufactured by Sekisui Chemical Co., Ltd .: Eslec CN) 1.0 part Toluene 21.4 parts Tetrahydrofuran 64.3 parts [2-hydroxy-4- (methacryloyloxyethoxy) benzophenone] -methyl methacrylate copolymer (trade name UVA635L manufactured by BASF) 0.88 part Isocyanate compound (trade name D140N manufactured by Takeda Pharmaceutical Company Limited) 1 .50 parts Tin catalyst (trade name: TK-1L, manufactured by Takeda Pharmaceutical Company) 0.60 parts Alcohol-modified silicone oil (trade name: SF8427, manufactured by Toray Silicone Co.) 0.62 parts Unmodified silicone oil (trade name: SH200 manufactured by Toray Silicone Co., Ltd.) Kinematic viscosity 1000cs) 0.62 parts

Example 13 Instead of synthetic paper, instead of a synthetic paper, a laminated body laminated in the order of synthetic paper / transparent PET / foamed PET was used, and a receiving layer forming liquid 13 having the following composition was applied on the foamed PET. A thermal transfer image-receiving sheet was produced in the same manner as in Example 1 except for the processing. <Dye receiving layer forming liquid 13> Polyvinyl acetal resin (manufactured by Chisso Corp .: Vinylek H) 6.6 parts Vinyl acetate resin Former Hosei Synthetic Chemical Industry Co., Ltd .: PV-500 2.8 parts Toluene 21.4 parts Tetrahydrofuran 64. 3 parts [2-hydroxy-4- (methacryloyloxyethoxy) benzophenone] -methyl methacrylate copolymer (trade name: UVA633L, manufactured by BASF) 0.88 parts Isocyanate compound (trade name: D140N, manufactured by Takeda Pharmaceutical Co., Ltd.) 2.60 Part Tin catalyst (trade name: TK-1L, manufactured by Takeda Pharmaceutical Company) 0.60 part Alcohol-modified silicone oil (trade name: SF8427, manufactured by Toray Silicone Co.) 0.62 part Unmodified silicone oil (trade name: SH200 kinematic viscosity manufactured by Toray Silicone Co., Ltd.) 1000cs) 0.62 parts

Example 14 A thermal transfer image-receiving sheet was produced in the same manner as in Example 13 except that the dye-receiving layer forming liquid 13 of Example 13 was replaced with the dye-receiving layer forming liquid 14 having the following composition. <Dye receiving layer forming liquid 14> Polyvinyl formal resin (manufactured by Chisso Corporation: Vinylek L) 6.6 parts PVC / vinyl acetate combined vehicle (manufactured by Sekisui Chemical Co., Ltd .: Eslec CN) 2.8 parts Toluene 21.4 parts Tetrahydrofuran 64.3 parts [2-hydroxy-4- (methacryloyloxyethoxy) benzophenone] -methyl methacrylate copolymer (trade name UVA635L manufactured by BASF) 0.88 part Isocyanate compound (trade name D140N manufactured by Takeda Pharmaceutical Co., Ltd.) 2 60 parts Tin catalyst (trade name TK-1L, manufactured by Takeda Pharmaceutical Company) 0.60 parts Alcohol-modified silicone oil (trade name: SF8427, manufactured by Toray Silicone Co.) 0.62 parts Unmodified silicone oil (trade name: SH200 manufactured by Toray Silicone Co., Ltd.) Kinematic viscosity 1000cs) 0.62 parts

Example 15 A thermal transfer image-receiving sheet was prepared in the same manner as in Example 13, except that the dye-receiving layer forming liquid 13 of Example 13 was replaced with the dye-receiving layer forming liquid 14 having the following composition. <Dye receiving layer forming liquid 15> Polyvinyl formal resin (manufactured by Chisso Corporation: Vinylek E) 3.5 parts PVC / vinyl acetate copolymer (manufactured by Sekisui Chemical Co., Ltd .: Eslec CN) 1.5 parts Toluene 21.4 parts Tetrahydrofuran 64.3 parts [2-hydroxy-4- (methacryloyloxyethoxy) benzophenone] -methyl methacrylate copolymer (trade name UVA635L, manufactured by BASF) 0.88 part Isocyanate compound (trade name, D140N, manufactured by Takeda Pharmaceutical Company Limited) 1 .50 parts Tin catalyst (trade name TK-1L, manufactured by Takeda Pharmaceutical Co., Ltd.) 0.60 parts Alcohol-modified silicone oil (trade name, SF8427, manufactured by Toray Silicone Co.) 0.62 parts Unmodified silicone oil (trade name, SH200 manufactured by Toray Silicone Co., Ltd.) Kinematic viscosity 1000cs) 0.62 parts

Comparative Example 1 A thermal transfer image-receiving sheet was prepared in the same manner as in Example 1 except that the dye-receiving layer forming solution 16 having the following composition was used instead of the dye-receiving layer forming solution 1 of Example 1. <Dye-receiving layer forming liquid 16> Polyester resin (VYLON290 manufactured by Toyobo Co., Ltd.) 9.38 parts Toluene 43.0 parts Methyl ethyl ketone 43.0 parts Alcohol-modified silicone oil (Toray Silicone Co., trade name SF8427) 0.62 parts Unmodified 0.62 parts of silicone oil (trade name: SH200, kinematic viscosity: 1000 cs, manufactured by Toray Silicone Co., Ltd.)

Comparative Example 2 A thermal transfer image-receiving sheet was prepared in the same manner as in Example 1 except that the dye-receiving layer forming liquid 17 having the following composition was used instead of the dye-receiving layer forming liquid 1 of Example 1. <Dye-receiving layer forming liquid 17> Polyvinyl formal resin (manufactured by Chisso Corporation: Vinylek L) 6.6 parts Cellulose acetate resin (manufactured by Eastman Chemical Company, CA-398-3 Vicat softening point 221 ° C) 2.8 parts Toluene 21 .4 parts Tetrahydrofuran 64.3 parts Alcohol-modified silicone oil (trade name: SF8427, manufactured by Toray Silicone) 0.62 parts Unmodified silicone oil (trade name: SH200, dynamic viscosity 1000cs, manufactured by Toray Silicone) 0.62 parts

Comparative Example 3 A thermal transfer image-receiving sheet was prepared in the same manner as in Example 1 except that the dye-receiving layer forming liquid 18 having the following composition was used in place of the dye-receiving layer forming liquid 1 of Example 1. <Dye-receiving layer forming liquid 18> Polyester resin (manufactured by Toyobo Co., Ltd .: VYLON200) 6.6 parts Vinyl acetate resin (manufactured by Nippon Synthetic Chemical Industry Co., Ltd .: PV-500) 2.8 parts Toluene 21.44 parts Methyl ethyl ketone 64.3 Part: alcohol-modified silicone oil (trade name: SF8427, manufactured by Toray Silicone Co.) 0.62 part: unmodified silicone oil (trade name: SH200, dynamic viscosity: 1000 cs, manufactured by Toray Silicone Co.) 0.62 part

Comparative Example 4 A thermal transfer image-receiving sheet was prepared in the same manner as in Example 1 except that the dye-receiving layer forming solution 19 having the following composition was used in place of the dye-receiving layer forming solution 1 of Example 1. <Dye-receiving layer forming solution 19> Polyvinyl formal resin (manufactured by Denki Kagaku Kogyo Co., Ltd .: # 100) 3.8 parts Vinyl acetate resin (PV-500 manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) 5.6 parts Toluene 21.4 parts Tetrahydrofuran 64 0.3 parts Alcohol-modified silicone oil (trade name: SF8427, manufactured by Toray Silicone Co.) 0.62 parts Unmodified silicone oil (trade name: SH200, manufactured by Toray Silicone Co., Ltd., kinematic viscosity: 1000 cs) 0.62 parts

Comparative Example 5 A thermal transfer image-receiving sheet was prepared in the same manner as in Example 1 except that the dye-receiving layer forming liquid 20 having the following composition was used in place of the dye-receiving layer forming liquid 1 of Example 1. <Dye-receiving layer forming liquid 20> Polyvinyl formal resin (manufactured by Chisso Corporation: Vinylek K) 6.6 parts Vinyl acetate resin (manufactured by Nippon Synthetic Chemical Industry Co., Ltd .: PV-500) 2.8 parts Toluene 21.4 parts Tetrahydrofuran 64. 3 parts Phenyl salicylate (melting point 42 ° C.) 0.52 parts Alcohol-modified silicone oil (trade name SF8427, manufactured by Toray Silicone Co.) 0.62 parts Unmodified silicone oil (brand name SH200, dynamic viscosity 1000 cs manufactured by Toray Silicone Co., Ltd.) 0 .62 copies

Comparative Example 6 A thermal transfer image-receiving sheet was prepared in the same manner as in Example 1 except that the dye-receiving layer forming solution 21 having the following composition was used in place of the dye-receiving layer forming solution 1 of Example 1. <Dye receiving layer forming liquid 21> 9.38 parts of vinyl chloride / vinyl acetate / vinyl alcohol copolymer (trade name of Denka Vinyl # 1000GKT manufactured by Denki Kagaku Kogyo Co., Ltd.) 21.4 parts of toluene 64.3 parts of methyl ethyl ketone 64.3 parts of isocyanate compound (Takeda Pharmaceutical Co., Ltd.) 3.20 parts Tin catalyst (trade name TK-1L, manufactured by Takeda Pharmaceutical Co., Ltd.) 0.60 parts Alcohol-modified silicone oil (trade name SF8427, manufactured by Toray Silicone Co.) 0.62 parts Unmodified silicone 0.62 parts of oil (trade name: SH200, kinematic viscosity: 1000 cs, manufactured by Toray Silicone Co., Ltd.)

Comparative Example 7 A thermal transfer image-receiving sheet was prepared in the same manner as in Example 1 except that the dye-receiving layer forming liquid 22 having the following composition was used instead of the dye-receiving layer forming liquid 1 of Example 1. <Dye-receiving layer forming liquid 22> Polyvinyl formal resin (manufactured by Chisso Corporation: Vinylek L) 3.5 parts Vinyl acetate resin (manufactured by Nippon Synthetic Chemical Industry Co., Ltd .: PV-500) 1.5 parts Toluene 21.4 parts Tetrahydrofuran 64. 3 parts Isocyanate compound (trade name: D103H, manufactured by Takeda Pharmaceutical Co., Ltd.) 5.40 parts Tin catalyst (trade name: TK-1L, manufactured by Takeda Pharmaceutical Co., Ltd.) 0.60 part Alcohol-modified silicone oil (trade name: SF8427 manufactured by Toray Silicone Co., Ltd.) 0 0.62 parts unmodified silicone oil (trade name: SH200, kinematic viscosity: 1000 cs, manufactured by Toray Silicone Co., Ltd.)

Comparative Example 8 A thermal transfer image-receiving sheet was prepared in the same manner as in Example 1 except that the dye-receiving layer forming liquid 22 having the following composition was used instead of the dye-receiving layer forming liquid 1 of Example 1. <Dye-receiving layer forming liquid> 9.38 parts of polyvinyl acetal resin (manufactured by Sekisui Chemical Co., Ltd .: KS-1) 21.4 parts of toluene 64.3 parts of methyl ethyl ketone 2 (2'-hydroxy-5'-methylphenyl) benzotriazole 0.5 part Isocyanate compound (trade name: D140N manufactured by Takeda Pharmaceutical Co., Ltd.) 2.60 parts Tin catalyst (trade name: TK-1L manufactured by Takeda Pharmaceutical Co., Ltd.) 0.60 part Alcohol-modified silicone oil (trade name: SF8427 manufactured by Toray Silicone Co., Ltd.) 0.62 parts Unmodified silicone oil (trade name: SH200, kinematic viscosity: 1000 cs, manufactured by Toray Silicone Co., Ltd.) 0.62 parts

[Comparative Example 9] In the same manner as in Comparative Example 8, except that a soft PVC sheet was used instead of synthetic paper as the base sheet, and a dye-receiving layer forming solution 24 having the following composition was used. A thermal transfer image receiving sheet was prepared. <Dye-receiving layer forming liquid 24> Polyvinyl formal resin (manufactured by Chisso Corporation: Vinylek H) 4.0 parts Epoxy resin (EPICLON 7050 manufactured by Dainippon Ink and Chemicals, Inc.) 1.0 part Toluene 21.4 parts Tetrahydrofuran 64.3 parts [ 2-hydroxy-4- (methacryloyloxyethoxy) benzophenone] -methyl methacrylate copolymer (trade name UVA635L, manufactured by BASF) 0.88 parts Isocyanate compound (trade name D140N, manufactured by Takeda Pharmaceutical Company) 2.60 parts tin Catalyst (Takeda Pharmaceutical Co., Ltd., trade name TK-1L) 0.60 parts Alcohol-modified silicone oil (Toray Silicone Co., Ltd., SF8427) 0.62 parts Unmodified silicone oil (Toray Silicone Co., Ltd., trade name SH200, kinematic viscosity 1000 cs) 0.62 parts

(Evaluation Test) A sublimation dye layer forming solution having the following formulation was applied on an aromatic polyamide film and dried to prepare a thermal sublimation transfer medium having a sublimation dye layer having a thickness of 4.5 μm. <Sublimation dye layer forming liquid> Polyvinyl butyral resin (trade name BX-1 manufactured by Sekisui Resin Co., Ltd.) 10 parts Sublimation dye (trade name Kayaset Blue 714 manufactured by Nippon Kayaku Co., Ltd.) 25 parts Isocyanate compound (trade name manufactured by Nippon Polyurethane Corporation) Coronate L) 10 parts Silicone oil (trade name: SF8417 manufactured by Toray Silicone Co., Ltd.) 1.5 parts Toluene 100 parts Methyl ethyl ketone 100 parts

The sublimation dye layer of the above-described thermal sublimation transfer medium and the dye receiving layer of the thermal transfer image-receiving sheet are overlapped so as to be in contact with each other.
Recording was performed under the following recording conditions, and the sensitivity, light resistance, print image quality / preservability were evaluated. Table 1 shows the evaluation results. <Recording conditions> Applied power: 442 mW / dot Thermal head: 6 dot / mm Partial grace (running speed of thermal transfer image receiving sheet) / (running speed of thermal sublimation transfer medium) = 7 to 30 Maximum printing energy: 2.21 mJ / Dot

<Recording Sensitivity> Image samples obtained under the above-mentioned recording conditions were measured with a Macbeth densitometer and evaluated according to the following criteria. ◎: extremely good sensitivity ：: good △: slightly insufficient density X: extremely poor sensitivity

<Light fastness> An image sample (without lamination) obtained under the above-mentioned recording conditions was irradiated with a xenon fade meter for 24 hours, and the image density remaining ratio (%) was measured. Was evaluated. Image density residual rate (%) = (image density before irradiation / image density after irradiation) × 100 (%) ：: Image density residual rate (%) is 80% or more ：: Image density residual rate (%) is 70% or more Less than 80% △: Residual rate of image density (%) is less than 60 to 70% ×: Residual rate of image density Δ%) is less than 60%

<Print Image Quality> The color tone, density unevenness, and the presence or absence of fusion of the cyan image printed under the above recording conditions were visually evaluated.

<Storability> The image sample printed with the equal density dot pattern was left at 60 ° C. for 100 hours, and the degree of dot bleeding was visually determined. The evaluation results of print image quality and storability were classified according to the following criteria. A: good B: slight density unevenness or slight dot bleeding in storage stability test C: severe fusion generation or density unevenness The above evaluation test results are summarized in Table 1.

[0091]

[Table 1]

[0092]

As described above, according to the thermal transfer image-receiving sheet containing at least the polyvinyl formal resin and the release agent in the dye receiving layer formed on at least one surface of the base sheet, a clear image density is obtained. An image is obtained, and a thermal transfer image-receiving sheet in which the formed image is excellent in light resistance, fusion resistance and storage stability is obtained. The polyvinyl formal resin is not only used alone,
(1) mixing a polyvinyl formal resin and a thermoplastic resin other than the polyvinyl formal resin,
(2) Use of a cured product (A) of a polyvinyl formal resin and a crosslinking agent, or (3) a curing reaction of a thermoplastic resin other than a polyvinyl formal resin and a crosslinking agent with the cured product (A). (4) Mixing the cured product (A) with a thermoplastic resin other than the polyvinyl formal resin and having no reactivity with a crosslinking agent (C). A heat transfer image receiving sheet is obtained.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yutaka Ariga 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd.

Claims (9)

[Claims] 1. A thermal transfer image receiving sheet having a dye receiving layer formed on at least one surface of a base sheet, wherein the dye receiving layer contains at least a polyvinyl formal resin and a release agent. Image receiving sheet. 2. A thermal transfer image-receiving sheet having a dye-receiving layer formed on at least one surface of a substrate sheet, wherein the dye-receiving layer contains at least a polyvinyl formal resin, a thermoplastic resin other than the polyvinyl formal resin, and a release agent. A heat transfer image-receiving sheet, characterized in that: 3. A thermal transfer image-receiving sheet having a dye-receiving layer formed on at least one surface of a substrate sheet, wherein the dye-receiving layer contains at least a curing reaction product of a polyvinyl formal resin and a crosslinking agent and a release agent. A heat transfer image-receiving sheet, characterized in that: 4. A thermal transfer image-receiving sheet having a dye-receiving layer formed on at least one surface of a substrate sheet, wherein the dye-receiving layer is at least a cured reactant represented by the following A;
A thermal transfer image-receiving sheet, comprising a curing reactant represented by the formula (1) and a release agent. A: Curing reactant of polyvinyl formal resin and crosslinking agent B: Curing reactant of thermoplastic resin other than polyvinyl formal resin and crosslinking agent 5. A thermal transfer image-receiving sheet having a dye-receiving layer formed on at least one surface of a substrate sheet, wherein the dye-receiving layer is at least a cured reactant represented by the following A;
A thermal transfer image-receiving sheet comprising a thermoplastic resin and a release agent represented by the formula: A: Curing reaction product of polyvinyl formal resin and crosslinking agent C: Thermoplastic resin other than polyvinyl formal resin
Not reactive with cross-linking agent 6. The thermal transfer image-receiving sheet according to claim 1, wherein the dye receiving layer has a Vicat softening temperature of 70 to 200 ° C. 7. The thermal transfer image-receiving sheet according to claim 2, wherein the Vicat softening temperature of the thermoplastic resin other than the polyvinyl formal resin is 100 ° C. or less. 8. The method according to claim 2, wherein the proportion of the thermoplastic resin other than the polyvinyl formal resin in the dye receiving layer is 5 to 50% by weight of the total amount of the resin forming the dye receiving layer. 5. The thermal transfer image-receiving sheet according to any one of 5. 9. The thermal transfer image-receiving sheet according to claim 3, wherein the crosslinking agent is a polyfunctional isocyanate compound.