JP2008087299A - Imaging method using heat transfer system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an imaging method, using a heat transfer system, which features high density, high image quality and good image fastness. <P>SOLUTION: The imaging method uses a heat-sensitive transfer image receiving sheet and a heat-sensitive transfer sheet. The heat-sensitive transfer image receiving sheet has one receptive layer formed on a support and one heat insulating layer containing a hollow polymer and a hydrophilic polymer between the receptive layer and the support. The heat-sensitive transfer sheet has three different kinds of heat transfer layers formed of a yellow dye, a magenta dye and a cyan dye respectively and formed on the support. The magenta dye contains one kind of a specific chemical compound represented by formula M-1, and the cyan dye contains only a specific chemical compound represented by formula C-1. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image forming method using a thermal transfer method that has high density, high image quality, and excellent image fastness.

Conventionally, various thermal transfer recording methods are known, and among them, the dye diffusion transfer recording method is attracting attention as a process capable of producing a color hard copy closest to the image quality of a silver salt photograph (for example, Non-Patent Document 1 and 2). In addition, it has the advantages of being dry, being able to visualize directly from digital data, and being easy to duplicate, compared to silver salt photography.
In this dye diffusion transfer recording system, a thermal transfer sheet (hereinafter also referred to as an ink sheet) containing a pigment and a thermal transfer image-receiving sheet (hereinafter also referred to as an image-receiving sheet) are superposed, and then heat is generated by an electrical signal. By heating the ink sheet with a controlled thermal head, the dye in the ink sheet is transferred to the image receiving sheet to record image information. By recording three colors of cyan, magenta, and yellow in an overlapping manner, A color image having a continuous change in color shading can be transferred and recorded.
Although it has been proposed to use various dyes in this manner (see, for example, Patent Documents 1 and 2), the fastness of the obtained image is not always sufficient, and further improvement in image quality has been demanded.
JP-A-7-232482 Japanese Patent Laid-Open No. 5-221116 “New development of information recording (hard copy) and its materials”, published by Toray Research Center, Inc., 1993, p. 241-285 “Development of printer materials”, issued by CMC Co., Ltd., 1995, p. 180

  The present invention has been made in response to the above requirements, and an object thereof is to provide an image forming method using a thermal transfer system, which has a high density, a low degree of dye reverse transfer, and excellent image fastness. .

The problems of the present invention have been solved by the following means.
(1) a thermal transfer image-receiving sheet having at least one receptor layer on a support and having at least one heat insulating layer containing a hollow polymer and a hydrophilic polymer between the receptor layer and the support; It has at least one thermal transfer layer composed of at least one yellow, magenta and cyan on the support, and the magenta dye contained in the magenta thermal transfer layer contains at least one compound represented by the following general formula (M). An image forming method comprising using a thermal transfer sheet in which a cyan dye contained in a cyan thermal transfer layer is only a compound represented by the following general formula (C).

(In the general formula (M), D ^{1 to} D ⁵ are each independently a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an aryl group, an aryloxy group, a cyano group, an acylamino group, a sulfonylamino group, a ureido group, Represents an alkoxycarbonylamino group, an alkylthio group, an arylthio group, an alkoxycarbonyl group, a carbamoyl group, a sulfamoyl group, a sulfonyl group, an acyl group or an amino group, and D ⁶ and D ⁷ each independently represents a hydrogen atom, an alkyl group or an aryl group. D ⁶ and D ⁷ may be bonded to each other to form a ring, and D ³ and D ⁶ or / and D ⁴ and D ⁷ may be bonded to each other to form a ring. Y and Z represent ═C (D ⁸ ) — or a nitrogen atom, where D ⁸ represents a hydrogen atom, an alkyl group, an aryl group, an alkoxy group, an aryloxy group. When X and Y are = C (D ⁸ )-, or when Y and Z are = C (D ⁸ )-, the two D ⁸ are bonded to each other to be saturated or unsaturated. (Saturated carbocycle may be formed. Each of these groups may further have a substituent.)

(In General Formula (C), D ^{9 to} D ¹⁶ are each independently a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an aryl group, an aryloxy group, a cyano group, an acylamino group, a sulfonylamino group, a ureido group, Represents an alkoxycarbonylamino group, an alkylthio group, an arylthio group, an alkoxycarbonyl group, a carbamoyl group, a sulfamoyl group, a sulfonyl group, an acyl group or an amino group, and D ¹⁷ and D ¹⁸ each independently represents a hydrogen atom, an alkyl group or an aryl group. D ¹⁷ and D ¹⁸ may be bonded to each other to form a ring, and D ¹⁴ and D ¹⁷ or / and D ¹⁵ and D ¹⁸ may be bonded to each other to form a ring. Each group may further have a substituent.)
(2) At least one kind of yellow dye in the yellow heat transfer layer of the heat-sensitive transfer sheet is a compound represented by any one of the following general formulas (YA) to (YE): The image forming method described.

(In the general formula (YA), R ¹¹ represents a monovalent substituent, R ¹² represents a hydrogen atom or a monovalent substituent, and Ar ¹ is a group selected from the group (1) of the following heterocyclic group. X represents an atomic group necessary for ring formation.)

(In the heterocyclic group (1), R ⁶¹ , R ⁶² , R ⁶³ , R ⁶⁴ and R ⁶⁵ each independently represents a hydrogen atom or a substituent.)

(In the general formula (YB), R ¹ , R ² , R ³ , R ⁶ and R ⁵ each independently represents a hydrogen atom or a monovalent substituent, and R ⁵ represents a monovalent substituent.)

(In the general formula (YC), R ^A , R ^B , R ^C , R ^D and R ^E are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group, an alkoxy group, an alkoxy group. An alkoxy group, an alkoxycarbonyl group, a thioalkoxy group, an alkylsulfonyl group, an amino group, a substituted or unsubstituted phenoxy group, or a substituted or unsubstituted thiophenoxy group, wherein R ^F and R ^G are each independently hydrogen; An atom, an alkyl group, an alkoxyalkyl group, a cycloalkyl group, an allyl group, an aryl group which may have a substituent, an aralkyl group, a furfuryl group, a tetrahydrofurfuryl group, or a hydroxyalkyl group.

(In General Formula (YD), R ^1A represents an allyl group or an alkyl group, R ^2A represents a substituted or unsubstituted alkyl group or an aryl group, and A represents —CH ₂ —, —CH ₂ CH ₂ —, — _{CH 2 CH 2 O -, -} CH 2 CH 2 OCH 2 - or _{-CH 2 CH 2 OCH 2 CH 2} -. represents, R ^3A represents an alkyl group have each of these groups are further substituted May be good.)

(In General Formula (YE), R ^1B and R ^2B are each independently a hydrogen atom, an optionally substituted alkyl group, an allyl group, an optionally substituted aryl group, or an optionally substituted group. Represents a cycloalkyl group, R ^3B represents a hydrogen atom, an optionally substituted alkyl group, an NR ^5C R ^6C group, an optionally substituted alkoxy group, an optionally substituted alkoxycarbonyl group, a substituted Represents a good aryl group or a C (O) NR ^5D R ^6D group, wherein R ^4B , R ^5C , R ^5D , R ^6C and R ^6D each independently represents a hydrogen atom, an optionally substituted alkyl group, Or, it represents an optionally substituted aryl group.)
(3) At least one of the yellow dyes in the yellow thermal transfer layer of the thermal transfer sheet is a compound represented by either the general formula (YA) or (YB) (1) or The image forming method according to (2).
(4) In the general formula (M), X and Z are nitrogen atoms, and Y is ═C (D ⁸ ) — (where D ⁸ is a hydrogen atom, alkyl group, aryl group, alkoxy group, aryl (It represents an oxy group or an amino group.) The image forming method according to any one of (1) to (3), wherein
(5) In the thermal transfer sheet, any one of (1) to (4) is characterized in that at least three types of thermal transfer layers of yellow, magenta, and cyan are formed in a surface sequence on a support. The image forming method according to item.
(6) The image forming method according to any one of (1) to (5), wherein the thermal transfer sheet further has a protective layer capable of thermal transfer.
(7) The protective layer capable of thermal transfer has an absorption maximum in a wavelength range of 330 to 370 nm, and has an absorption density of 0.8 or more at the maximum absorption wavelength (6) ) Image forming method.
(8) The image forming method according to any one of (1) to (7), wherein in the heat-sensitive transfer image-receiving sheet, at least one hydrophilic polymer contained in the heat insulating layer is gelatin. .
(9) The image forming method according to any one of (1) to (8), wherein the thermal transfer layer of the thermal transfer sheet and the receiving layer of the thermal transfer image receiving sheet are in contact with each other, and the image is transferred from the thermal head. An image forming method, wherein an image is formed by forming an image by applying thermal energy according to a signal.

  According to the present invention, it is possible to provide an image forming method using a thermal transfer method that has high density, high image quality, and excellent image fastness.

Hereinafter, the present invention will be described in detail.
First, a thermal transfer image receiving sheet (image receiving sheet) will be described.

1) Thermal transfer image-receiving sheet The thermal transfer image-receiving sheet used in the present invention has at least one dye-receiving layer (receiving layer) on a support, and at least one layer of heat insulation between the support and the receiving layer. It has a layer (porous layer). In addition, an underlayer such as a white background adjusting layer, a charge adjusting layer, an adhesive layer, or a primer layer may be formed between the receiving layer and the heat insulating layer.
The receiving layer and the heat insulating layer are preferably formed by simultaneous multilayer coating. When the underlayer is included, the receiving layer, the underlayer and the heat insulating layer can be formed by simultaneous multilayer coating.
It is preferable that a curl adjusting layer, a writing layer, and a charge adjusting layer are formed on the back side of the support. Each layer on the back side of the support can be applied by a general method such as roll coating, bar coating, gravure coating, or gravure reverse coating.

<Receptive layer>
[Thermoplastic resin]
In the present invention, a thermoplastic resin is preferably used for the receiving layer. Examples of preferred thermoplastic resins include halogenated polymers such as polyvinyl chloride and polyvinylidene chloride, polyvinyl acetate, ethylene vinyl acetate copolymer, vinyl chloride vinyl acetate copolymer, polyacrylic ester, polystyrene, polystyrene acrylic, etc. Vinyl resins, acetal resins such as polyvinyl formal, polyvinyl butyral, and polyvinyl acetal, polyester resins such as polyethylene terephthalate, polybutylene terephthalate, and polycaprolactone (Placcel H-5, trade name, manufactured by Daicel Chemical Industries, Ltd.) Polycarbonate resin, cellulose resin and cellulose acetate butyrate described in JP-A-4-296595 and JP-A-2002-264543 (CAB551-0.2, CAB321-0.1, Izu) Trade name, manufactured by Eastman Chemical Company) cellulose resins such as polyolefin resins such as polypropylene, polyamide resins such as urea resins, melamine resins, benzoguanamine resins. These resins can be arbitrarily blended and used within a compatible range. JP-A-57-169370, JP-A-57-207250, JP-A-60-25793, etc. also disclose resins having a receiving layer formed therein.

  Among the above polymers, it is more preferable to contain polycarbonate, polyester, polyurethane, polyvinyl chloride and a copolymer thereof, styrene-acrylonitrile copolymer, polycaprolactone or a mixture thereof, and polycarbonate, polyester, polyvinyl chloride and a copolymer thereof. A combination or a mixture thereof is particularly preferred. Polycarbonate, polyester, and polyvinyl chloride will be described in more detail. The above polymers can be used alone or as a mixture thereof.

(Polyester polymer)
The polyester polymer used for the receiving layer will be described in more detail. Polyester is obtained by polycondensation of a dicarboxylic acid component (including derivatives thereof) and a diol component (including derivatives thereof). The polyester polymer contains an aromatic ring and / or an alicyclic ring. Regarding the technology of alicyclic polyester, the technology described in JP-A-5-238167 is effective in terms of dye uptake ability and image stability.

  The dicarboxylic acid component is selected from adipic acid, azelaic acid, isophthalic acid, trimellitic acid, terephthalic acid, 1,4-cyclohexanedicarboxylic acid, and a mixture of two or more thereof. Preferably, it is selected from isophthalic acid, trimellitic acid, terephthalic acid, or a mixture of two or more thereof. Inclusion of an alicyclic component as the dicarboxylic acid component is more desirable from the viewpoint of improving light resistance. More preferably, 1,4-cyclohexanedicarboxylic acid and isophthalic acid are used. The dicarboxylic acid component is used in a proportion of 50 to 100 mol% of isophthalic acid, 0 to 1 mol% of trimellitic acid, 0 to 50 mol% of terephthalic acid, and 0 to 15 mol% of 1,4-cyclohexanedicarboxylic acid. To do.

  The diol component can be selected from ethylene glycol, polyethylene glycol, tricyclodecane dimethanol, 1,4-butanediol, bisphenol, or a mixture of two or more thereof. Preferably, it is selected from ethylene glycol, polyethylene glycol, and tricyclodecane dimethanol. It is more desirable to include an alicyclic component as a diol component from the viewpoint of improving light resistance. In addition to tricyclodecane dimethanol, alicyclic diol components such as cyclohexane diol, cyclohexane dimethanol, and cyclohexane diethanol can be used. A preferred alicyclic diol component is tricyclodecane dimethanol. The diol component is ethylene glycol 0 to 50 mol /%, polyethylene glycol 0 to 10 mol /%, tricyclodecane dimethanol 0 to 90 mol /%, preferably 30 to 90 mol /%, more preferably 40 to 90 mol /%, 4-butanediol is used at a ratio of 0 to 50 mol /% and bisphenol A 0 to 50 mol /% so that the total amount is 100 mol%.

  In the present invention, at least the above-described dicarboxylic acid component and diol component are used so that the molecular weight (mass average molecular weight (Mw)) is usually about 11,000 or more, preferably about 15000 or more, more preferably about 17000 or more. Polycondensed polyester polymer is used. If the molecular weight is too low, the elasticity of the receptor layer to be formed will be low and the heat resistance will be insufficient, so it may be difficult to ensure the releasability between the thermal transfer sheet and the image receiving sheet. . The molecular weight is preferably as large as possible from the viewpoint of increasing the elastic modulus, and cannot be dissolved in the coating solution solvent at the time of forming the receiving layer, or the adhesiveness to the base sheet may be adversely affected after the receiving layer is applied and dried. There is no particular limitation as long as no adverse effects occur, but it is preferably about 25,000 or less, and at most about 30000. In addition, what is necessary is just to use a conventionally well-known method as a synthesis method of ester polymer.

  Examples of saturated polyesters include Byron 200, Byron 290, Byron 600, etc. (all trade names, manufactured by Toyobo Co., Ltd.), KA-1038C (trade names, manufactured by Arakawa Chemical Industries, Ltd.), TP220, TP235 (all A trade name, manufactured by Nippon Synthetic Chemical Co., Ltd.) is used.

(Polycarbonate polymer)
The polycarbonate-based polymer used for the receiving layer will be described in more detail. Polycarbonate means polyester having units of carbonic acid and diol, and can be synthesized by a method of reacting diol with phosgene or a method of reacting carbonate ester.

  Diol components include bisphenol A, ethylene glycol, propylene glycol, diethylene glycol, butanediol, pentanediol, hexanediol, 1,4-cyclohexanedimethanol, nonanediol, 4,4'-bicyclo (2,2,2) hept 2-ylidenebisphenol, 4,4 ′-(octahydro-4,7-methano-5H-indene-5-ylidene) bisphenol and 2,2 ′, 6,6′-tetrachlorobisphenol A, and bisphenol A, ethylene glycol, diethylene glycol, butanediol and pentanediol are preferred, bisphenol A, ethylene glycol and butanediol are more preferred, and bisphenol A and ethylene glycol are particularly preferred. The polycarbonate used in the present invention uses at least the above-mentioned one kind of diol component, but a plurality of diols may be mixed and used.

  The bisphenol A-polycarbonate, which is a particularly preferred embodiment of the polycarbonate used in the present invention, will be described in detail. The technique of unmodified polycarbonate, centered on bisphenol A-polycarbonate, is described in US Pat. No. 4,695,286. The polycarbonate used in the present invention has a polycondensation having a molecular weight (mass average molecular weight (Mw)) of usually about 1000 or more, preferably about 3000 or more, more preferably about 5000 or more, particularly preferably about 10,000 or more. Polycarbonates such as Makrolon-5700 (trade name, manufactured by Bayer AG) and LEXAN-141 (trade name, manufactured by General Electric) can be mentioned as examples.

  A technique for producing a modified polycarbonate by mixing bisphenol A and a diol such as ethylene glycol is described in US Pat. No. 4,927,803. The polyether block unit can be formed from a linear aliphatic diol having from 2 to about 10 carbon atoms, but is preferably formed from ethylene glycol. In a preferred embodiment of the present invention, the polyether block units have a number molecular weight of about 4,000 to about 50,000 and the bisphenol A-polycarbonate block units have a number molecular weight of about 15,000 to about 250,000. The overall molecular weight of the block copolymer is preferably from about 30,000 to about 300,000. Specific examples thereof include Makrolon KL3-1013 (trade name, manufactured by Bayer AG).

  It is also preferable to mix these unmodified and modified bisphenol A-polycarbonates, and it is preferable to blend unmodified bisphenol A-polycarbonates and polyether-modified polycarbonates in a mass ratio of 80:20 to 10:90, improving fingerprint resistance. From the viewpoint of mass ratio, a mass ratio of 50:50 to 40:60 is particularly preferable. The blending technology of unmodified and modified bisphenol A-polycarbonate is also described in JP-A-6-227160.

  As a preferred embodiment of the thermoplastic resin used in the receiving layer, a blend system of the above polycarbonate and the above polyester can be mentioned. In this blend system, it is preferable that the compatibility between the polycarbonate and the polyester can be ensured. The polyester preferably exhibits a glass transition temperature (Tg) of about 40 to about 100 ° C, and the polycarbonate exhibits a Tg of about 100 to about 200 ° C. The polyester preferably exhibits a lower Tg than polycarbonate and acts as a polymer plasticizer for the polycarbonate. The Tg of the final polyester / polycarbonate blend is preferably 40 ° C to 100 ° C. Higher Tg polyester and polycarbonate polymers can also be useful by adding plasticizers.

  In a further preferred embodiment, the unmodified bisphenol A-polycarbonate and the polyester polymer are blended in a mass ratio that will bring the final blend Tg to the desired value and minimize cost. The polycarbonate and polyester polymer can be conveniently blended in a mass ratio of about 75:25 to 25:75, but more preferably in a mass ratio of about 60:40 to about 40:60. Japanese Patent Application Laid-Open No. 6-227161 discloses a technique of blending polycarbonate and polyester.

  In the polycarbonate used in the receiving layer, a polymer network structure is formed in the receiving layer by reacting the polycarbonate having an average molecular weight of about 1000 to about 10,000 having at least two hydroxyl groups with a crosslinking agent that reacts with hydroxyl groups. It may be formed. As described in JP-A-6-155933, there is also a technique of a crosslinking agent such as a polyfunctional isocyanate, which can improve the adhesion to a dye donor after transfer. Furthermore, as in the technique disclosed in Japanese Patent Laid-Open No. 8-39942, there is also a technique for constructing a thermal transfer receiving sheet using dibutyltin diacetate in the crosslinking reaction between polycarbonate and isocyanate. It is also possible to improve image stability and fingerprint resistance.

(Vinyl chloride polymer)
A vinyl chloride polymer used for the receiving layer, particularly a copolymer using vinyl chloride, will be described in more detail.
The vinyl chloride copolymer preferably has a vinyl chloride component content of 85 to 97% by mass and a polymerization degree of 200 to 800. The monomer copolymerized with vinyl chloride is not particularly limited, as long as it can be copolymerized with vinyl chloride, and vinyl acetate is particularly preferable. Therefore, vinyl chloride-vinyl acetate copolymer is excellent as the vinyl chloride polymer used in the receiving layer, but vinyl chloride-vinyl acetate copolymer is not necessarily a copolymer of only vinyl chloride component and vinyl acetate component. It may contain a vinyl alcohol component, a maleic acid component, etc. of the range which does not interfere with the objective of this invention not only in a certain case. Other monomer components constituting such a copolymer comprising vinyl chloride and vinyl acetate as main monomers include vinyl alcohol derivatives such as vinyl alcohol and vinyl propionate; acrylic acid and methacrylic acid and their Acrylic acid and methacrylic acid derivatives such as methyl, ethyl, propyl, butyl, 2-ethylhexyl ester; maleic acid derivatives such as maleic acid, diethyl maleate, dibutyl maleate, dioctyl maleate; methyl vinyl ether, butyl vinyl ether, 2-ethylhexyl Vinyl ether derivatives such as vinyl ether; acrylonitrile, methacrylonitrile, styrene and the like. The component ratio of vinyl chloride and vinyl acetate incorporated in the copolymer may be any ratio, but the vinyl chloride component is preferably 50% by mass or more in the copolymer. Moreover, it is preferable that components other than vinyl chloride and vinyl acetate mentioned above are 10 mass% or less.

  Such vinyl chloride-vinyl acetate copolymers include SOLBIN C, SOLBIN CL, SOLBIN CH, SOLBIN CN, SOLBIN C5, SOLBIN M, SOLBIN MF, SOLBIN A, SOLBIN AL, SOLBIN TA5R, SOLBIN TAO, SOLBIN, MOL SOLBIN TA2 (all trade names, manufactured by Nissin Chemical Industry Co., Ltd.), ESREC A, ESREC C, ESREC M (all trade names, manufactured by Sekisui Chemical Co., Ltd.), Vinylite VAGH, Vinylite VYHH, Vinylite VMCH, VINYLITE VYHD, VINYLITE VYLF, VINYLITE VYNS, VINYLITE VMCC, VINYLITE VMCA, VINYLITE VAGD, VINYLITE VERR, VINYLITE VROH (all trade names and unions) DENKA Vinyl 1000GKT, Denka Vinyl 1000L, Denka Vinyl 1000CK, Denka Vinyl 1000A, Denka Vinyl 1000LK2, Denka Vinyl 1000AS, Denka Vinyl 1000MT2, Denka Vinyl 1000CSK, Denka Vinyl 1000CS, Denka Vinyl 1000 Vinyl GS, Denka Vinyl 1000vinyl LS Any of them may be trade names, manufactured by Denki Kagaku Kogyo Co., Ltd.).

(Polymer latex)
In the present invention, a polymer latex can be preferably used in addition to the above. Hereinafter, the polymer latex will be described.
In the heat-sensitive transfer image-receiving sheet used in the present invention, the polymer latex that can be used in the receiving layer is preferably a polymer in which a hydrophobic polymer containing water-insoluble vinyl chloride as a monomer unit is dispersed as fine particles in a water-soluble dispersion medium. As the dispersion state, the polymer is emulsified in a dispersion medium, the emulsion is polymerized, the micelle is dispersed, or the polymer molecule has a partially hydrophilic structure and the molecular chain itself is molecularly dispersed. Anything may be used. For polymer latex, Tadashi Okuda, Hiroshi Inagaki, “Synthetic Resin Emulsion”, published by Kobunshi Publishing (1978); Takaaki Sugimura, Akio Kataoka, Junichi Suzuki, Keiji Kasahara, “Application of Synthetic Latex”, Takashi Published by Molecular Publications (1993); Soichi Muroi, “Chemistry of Synthetic Latex”, published by High Polymer Publications (1970); 2004) and JP-A-64-538. The average particle size of the dispersed particles is preferably about 1 to 50000 nm, more preferably about 5 to 1000 nm.
The particle size distribution of the dispersed particles is not particularly limited, and may have a wide particle size distribution or a monodispersed particle size distribution.

  The polymer latex may be a normal uniform structure polymer latex or a so-called core / shell type latex. At this time, it may be preferable to change the glass transition temperature between the core and the shell. The glass transition temperature of the polymer latex used in the present invention is preferably −30 ° C. to 100 ° C., more preferably 0 ° C. to 80 ° C., further preferably 10 ° C. to 70 ° C., and particularly preferably 15 ° C. to 60 ° C.

  As the polymer latex used in the receiving layer, polyvinyl chlorides and copolymers containing vinyl chloride as monomer units, for example, vinyl chloride vinyl acetate copolymers and vinyl chloride acrylic copolymer polymers can be preferably used. In this case, the ratio of the vinyl chloride monomer is preferably 50% to 95%. These polymers may be linear polymers, branched polymers, crosslinked polymers, so-called homopolymers obtained by polymerizing a single monomer, or two or more types of monomers. It may be a polymerized copolymer. In the case of a copolymer, it may be a random copolymer or a block copolymer. The number average molecular weight of these polymers is usually 5,000 to 100,000, preferably 10,000 to 500,000. When the molecular weight is too small, the layer containing the latex may have insufficient mechanical strength, and when it is too large, the film formability may be poor. A crosslinkable polymer latex is also preferably used.

  The polymer latex that can be used in the present invention is commercially available, and the following polymers can be used. Examples include G351 and G576 manufactured by Nippon Zeon Co., Ltd., Vinibrand 240, 270, 277, 375, 386, 609, 550, 601, 602, 630, 660, 671, 683, 680 manufactured by Nissin Chemical Industry Co., Ltd. 680S, 681N, 685R, 277, 380, 381, 410, 430, 432, 860, 863, 865, 867, 900, 900GT, 938, 950, etc. (all are trade names).

These polymer latexes may be used alone or in combination of two or more as required.
In the receiving layer, the copolymer latex containing vinyl chloride as a monomer unit is preferably 50% or more in terms of the total solid content in the layer.

  In the present invention, it is preferable to prepare the receptor layer by applying an aqueous coating solution and then drying it. However, “aqueous” as used herein means that 60% by mass or more of the solvent (dispersion medium) of the coating solution is water. Components other than water in the coating solution include methyl alcohol, ethyl alcohol, isopropyl alcohol, methyl cellosolve, ethyl cellosolve, dimethylformamide, ethyl acetate, diacetone alcohol, furfuryl alcohol, benzyl alcohol, diethylene glycol monoethyl ether, oxyethylphenyl A water-miscible organic solvent such as ether can be used.

The minimum film-forming temperature (MFT) of the polymer latex is usually −30 ° C. to 90 ° C., preferably about 0 ° C. to 70 ° C. In order to control the minimum film forming temperature, a film forming aid may be added. A film-forming aid, also called a temporary plasticizer, is an organic compound (usually an organic solvent) that lowers the minimum film-forming temperature of polymer latex. For example, Soichi Muroi, “Synthetic Latex Chemistry”, published by Kobunshi Shuppankai (1970) )It is described in. Preferred examples of the film-forming aid include the following compounds, but the film-forming aid that can be used in the present invention is not limited to the following specific examples.
Z-1: benzyl alcohol Z-2: 2,2,4-trimethylpentanediol-1,3-monoisobutyrate Z-3: 2-dimethylaminoethanol Z-4: diethylene glycol

  In the present invention, the above polymer latex may be used (blended) with other polymer latex. Preferable examples of such polymer latex include polylactic acid esters, polyurethanes, polycarbonates, polyesters, polyacetals, and SBRs. Among these, polyesters and polycarbonates can be mentioned.

  Furthermore, the polymer latex used in the present invention may be used in combination with any polymer together with the polymer latex. The polymer that can be used in combination is preferably transparent or translucent and colorless. Natural resins, polymers and copolymers, synthetic resins, polymers and copolymers, and other media for forming films such as gelatins and polyvinyl alcohol , Hydroxyethyl cellulose, cellulose acetate, cellulose acetate butyrate, polyvinylpyrrolidone, casein, starch, polyacrylic acid, polymethylmethacrylic acid, polyvinylchloride, polymethacrylic acid, styrene-maleic anhydride copolymer Styrene-acrylonitrile copolymers, styrene-butadiene copolymers, polyvinyl acetals (eg, polyvinyl formal and polyvinyl butyral), polyesters, polyurethanes, Phenoxy resins, polyvinylidene chlorides, polyepoxides, polycarbonates, polyvinyl acetates, polyolefins, polyamides such. The binder may be formed from water, an organic solvent, or an emulsion.

  The binder used in the present invention preferably has a glass transition temperature (Tg) in the range of −30 ° C. to 70 ° C., more preferably in the range of −10 ° C. to 50 ° C. in view of processing brittleness and image storage stability. Preferably it is the range of 0 degreeC-40 degreeC. It is also possible to use a blend of two or more polymers as the binder, and in this case, it is preferable that the weighted average Tg in consideration of the composition falls within the above range. Moreover, when phase-separating or having a core-shell structure, the weighted average Tg is preferably within the above range.

This glass transition temperature (Tg) can be calculated by the following formula.
1 / Tg = Σ (Xi / Tgi)
Here, it is assumed that n monomer components from i = 1 to n are copolymerized in the polymer. Xi is the mass fraction of the i-th monomer (ΣXi = 1), and Tgi is the glass transition temperature (absolute temperature) of the homopolymer of the i-th monomer. However, Σ is the sum from i = 1 to n. In addition, the value of the homopolymer glass transition temperature (Tgi) of each monomer can adopt the value of “Polymer Handbook (3rd Edition)” (J. Brandrup, EHImmergut (Wiley-Interscience, 1989)).

  In the present invention, the polymer used for the binder can be easily obtained by a solution polymerization method, suspension polymerization method, emulsion polymerization method, dispersion polymerization method, anion polymerization method, cationic polymerization, etc. Legal is most preferred. Also preferred is a method of preparing a polymer in a solution and neutralizing or adding an emulsifier and then adding water and forcibly stirring to prepare an aqueous dispersion. In the emulsion polymerization method, for example, water or a mixed solvent of water and an organic solvent miscible with water (for example, methanol, ethanol, acetone, etc.) is used as a dispersion medium, and the monomer is 5 to 150% by mass with respect to the dispersion medium. An emulsifier and a polymerization initiator are used with respect to the mixture and the total amount of monomers, and the polymerization is usually carried out with stirring at about 30 to 100 ° C., preferably 60 to 90 ° C. for 3 to 24 hours. Various conditions such as the dispersion medium, the monomer concentration, the initiator amount, the emulsifier amount, the dispersant amount, the reaction temperature, and the monomer addition method are appropriately set in consideration of the type of monomer used. Moreover, it is preferable to use a dispersing agent as needed.

  In the polymer latex used in the present invention, an aqueous solvent can be used as a solvent in the coating solution, but a water-miscible organic solvent may be used in combination. Examples of the water-miscible organic solvent include alcohols such as methyl alcohol, ethyl alcohol and propyl alcohol, cellosolves such as methyl cellosolve, ethyl cellosolve and butyl cellosolve, ethyl acetate and dimethylformamide. The amount of these organic solvents added is preferably 50% by mass or less, more preferably 30% by mass or less of the solvent.

The polymer latex used in the present invention preferably has a polymer concentration of 10 to 70% by mass, more preferably 20 to 60% by mass, and particularly preferably 30 to 55% by mass with respect to the latex liquid.
In addition, the polymer latex in the image-receiving sheet of the present invention includes a gel or dry film state formed by drying a part of the solvent after coating.

[Emulsified dispersion]
In the present invention, it is preferable to contain an emulsified dispersion (emulsion) in the receiving layer. This is particularly preferable when a polymer latex is used.
Here, “emulsification” follows the commonly used definition. For example, according to the Dictionary of Chemistry (Kyoritsu Shuppan Co., Ltd.), “emulsification” is defined as “a phenomenon in which another liquid that does not dissolve in one liquid is dispersed as fine particles to produce an emulsion”. The “emulsified dispersion” refers to “liquid droplets that are dispersed in another liquid that does not dissolve them”. In the present invention, a preferable “emulsified dispersion” is an “oil droplet dispersion dispersed in water”. The content of an emulsified dispersion in the image-receiving sheet of the present invention is preferably contained 0.03g / m ² ~25.0g / m ² in the image-receiving ^{sheet, 1.0g / m 2 ~20.0g / m} 2 More preferably it is included.

In the present invention, it is preferable that a high boiling point solvent is contained in the oil-soluble component of the emulsified dispersion. Preferred high boiling point solvents include phthalates (dibutyl phthalate, dioctyl phthalate, di-2-ethylhexyl phthalate, etc.), phosphoric acid or phosphonic esters (triphenyl phosphate, tricresyl phosphate, triphosphate phosphate). 2-ethylhexyl, etc.), fatty acid esters (di-2-ethylhexyl succinate, tributyl citrate, etc.), benzoates (2-ethylhexyl benzoate, dodecyl benzoate, etc.), amides (N, N-diethyl, etc.) Dodecanamide, N, N-dimethyloleamide, etc.), alcohol or phenols (isostearyl alcohol, 2,4-di-tert-amylphenol, etc.), anilines (N, N-dibutyl-2-butoxy-5-) tert-octylaniline), chlorinated paraffins, hydrocarbons ( Decylbenzene, diisopropylnaphthalene, etc.), carboxylic acids (2- (2,4-di-tert-amylphenoxy) butyric acid, etc. More preferably, the high boiling point solvent is phosphoric acid or phosphonic acid esters (phosphoric acid triphosphate). Phenyl, tricresyl phosphate, tri-2-ethylhexyl phosphate, etc. In addition, as an auxiliary solvent, an organic solvent having a boiling point of 30 ° C. or higher and 160 ° C. or lower (ethyl acetate, butyl acetate, methyl ethyl ketone, cyclohexanone, methyl cellosolve acetate, dimethyl) The high boiling point solvent is preferably contained in the emulsion dispersion in an amount of 3.0 to 25% by mass, more preferably 5.0 to 20% by mass.
Further, the emulsified dispersion preferably contains an image fastening agent and an ultraviolet absorber. As these compounds, the general formulas (B), (Ph), (E-1) to (E-3), (TS-I) to (TS-VII) described in JP-A-2004-361936, A compound represented by any of (TS-VIIIA) and (UA) to (UE) is preferable. Further, it may contain a water-insoluble and organic solvent-soluble homopolymer or copolymer (preferably the compounds described in paragraph Nos. 0208 to 0234 of JP-A No. 2004-361936).

[Plasticizer]
In order to improve the sensitivity of the receiving layer, a plasticizer (high boiling point organic solvent) can also be added. Examples of such plasticizers include monomeric plasticizers such as phthalic acid esters, phosphoric acid esters, adipic acid esters, and sebacic acid esters, and polyester-type plasticizers obtained by polymerizing adipic acid, sebacic acid, and propylene glycol. In general, those which can be used as plasticizers for vinyl chloride resins are mentioned. The plasticizers listed above generally have a low molecular weight, but other olefin-based special copolymer resins used as vinyl chloride polymer plasticizers can also be used. Resins used for such applications are commercially available as Elvalloy 741, Elvalloy 742, Elvalloy HP443, Elvalloy HP553, Elvalloy EP4015, Elvalloy EP4043, Elvalloy EP4051 (all trade names, manufactured by Mitsui DuPont Polychemical Co., Ltd.). You can use what you have. Such a plasticizer can be added in an amount of about 100% by mass with respect to the resin, but the amount used is preferably 30% by mass or less in terms of bleeding of the printed matter. In addition, when using polymer latex, it is preferable to use these plasticizers as an emulsified dispersion as mentioned above.

  The receptor layer can be cast by extrusion coating the melt of the polymer resin, without solvent application. This extrusion coating technique is described in Encyclopedia of Polymer Science and Engineering, Volume 3 (John Wiley, New York), 1985, p. 563, Volume, 1986, page 608. Japanese Patent Application Laid-Open No. 7-179075 also discloses a technique relating to a thermal dye transfer material, and this technique can also be suitably used. As the polymer resin, a copolymer obtained by condensing cyclohexane dicarboxylate and a 50/50 mol% mixture (COPOL; registered trademark) of ethylene glycol / bisphenol A-diethanol is particularly preferable.

[Release agent]
If the image-receiving surface of the heat-sensitive transfer image-receiving sheet does not have sufficient peeling performance, the heat-sensitive transfer sheet and the heat-sensitive transfer image-receiving sheet (image-receiving sheet) are fused by heat from the thermal head during image formation, and a large peeling sound is generated during peeling. In addition, there is a problem of so-called abnormal transfer in which the dye layer is transferred layer by layer or the receiving layer is peeled off from the substrate. As a method for solving the above problem of peelability, there are known a method of internally adding various release agents into the receiving layer, or a method of separately providing a release layer on the receiving layer. In the present invention, it is preferable to use a release agent in the receiving layer in order to ensure the releasability between the heat-sensitive transfer sheet and the image receiving sheet during image printing.
Examples of release agents include solid waxes such as polyethylene wax, amide wax, and Teflon powder (Teflon: registered trademark); silicone oil, phosphate ester compounds, fluorine surfactants, silicone surfactants, and others. Release agents known in the art can be used, and silicone compounds such as fluorine compounds represented by fluorine surfactants, silicone surfactants, silicone oils and / or cured products thereof can be used. Preferably used.

  As the silicone oil, straight silicone oil, modified silicone oil or a cured product thereof can be used. Straight silicone oils include dimethyl silicone oil, methylphenyl silicone oil, and methyl hydrogen silicone oil. Examples of dimethyl silicone oil include KF96-10, KF96-100, KF96-1000, KF96H-10000, KF96H-12500, and KF96H. -100,000 (all are trade names, manufactured by Shin-Etsu Chemical Co., Ltd.) and the like, and as dimethyl silicone oil, KF50-100, KF54, KF56 (all are trade names, manufactured by Shin-Etsu Chemical Co., Ltd.), etc. Can be mentioned.

  The modified silicone oil can be classified into a reactive silicone oil and a non-reactive silicone oil. The reactive silicone oil includes amino modification, epoxy modification, carboxyl modification, hydroxy modification, methacryl modification, mercapto modification, phenol modification, one-terminal reactivity and heterofunctional modification. As amino-modified silicone oil, KF-393, KF-857, KF-858, X-22-3680, X-22-3801C, KF-8010, X-22-161A, KF-8012 (all trade names, Shin-Etsu Chemical Co., Ltd.), etc., and epoxy-modified silicone oils include KF-100T, KF-101, KF-60-164, KF-103, X-22-343, X-22-3000T ( All of them are trade names, manufactured by Shin-Etsu Chemical Co., Ltd.). Examples of the carboxyl-modified silicone oil include X-22-162C (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.). Examples of the hydroxy-modified silicone oil include X-22-160AS, KF-6001, KF-6002, KF-6003, X-22-170DX, X-22-176DX, X-22-176D, X-22-176DF (all trade names, manufactured by Shin-Etsu Chemical Co., Ltd.) X-22-164A, X-22-164C, X-24-8201, X-22-174D, X-22-2426 (all are trade names, manufactured by Shin-Etsu Chemical Co., Ltd.) and the like. .

  The reactive silicone oil can be used after being cured, and can be classified into a reaction curable type, a photo curable type, a catalyst curable type, and the like. Of these, reaction-curable silicone oils are particularly preferable. As the reaction-curable silicone oils, those obtained by reaction-curing amino-modified silicone oil and epoxy-modified silicone oil are preferable. Further, as the catalyst curable type or photo curable type silicone oil, KS-705F-PS, KS-705F-PS-1, KS-770-PL-3 [catalyst curable type silicone oil: all trade names, Shin-Etsu Chemical Co., Ltd. Co., Ltd.], KS-720, KS-774-PL-3 [photocured silicone oil: trade names, manufactured by Shin-Etsu Chemical Co., Ltd.], and the like. The addition amount of these curable silicone oils is preferably 0.5 to 30% by mass of the resin constituting the image receiving layer. The release agent is usually used in an amount of 2 to 4% by mass, preferably about 2 to 3% by mass, based on 100 parts by mass of the polyester resin. If the amount is too small, the releasability cannot be ensured, and if the amount is too large, the protective layer will not be transferred to the image receiving sheet.

  Non-reactive silicone oils include polyether modification, methylstyryl modification, alkyl modification, higher fatty acid ester modification, hydrophilic special modification, higher alkoxy modification, fluorine modification and the like. Examples include polyether-modified silicone (KF-6012, trade name, manufactured by Shin-Etsu Chemical Co., Ltd.), and methylstil-modified silicone silicone oil (24-510, trade name, manufactured by Shin-Etsu Chemical Co., Ltd.). Can be mentioned. Moreover, the modified silicone represented by either of the following general formulas 1-3 can also be used.

  In general formula 1, R represents a hydrogen atom or a linear or branched alkyl group which may be substituted with an aryl group or a cycloalkyl group. m and n each independently represent an integer of 2000 or less, and a and b each independently represent an integer of 30 or less.

  In General Formula 2, R represents a hydrogen atom or a linear or branched alkyl group which may be substituted with an aryl group or a cycloalkyl group. m represents an integer of 2000 or less, and a and b each independently represent an integer of 30 or less.

In General Formula 3, R represents a hydrogen atom or a linear or branched alkyl group which may be substituted with an aryl group or a cycloalkyl group. m and n each independently represent an integer of 2000 or less, and a and b each independently represent an integer of 30 or less. R ¹ represents a single bond or a divalent linking group, E represents an ethylene group or a substituted ethylene group, and P represents a propylene group or a substituted propylene group.

Silicone oils such as those described above are described in “Silicone Handbook” (published by Nikkan Kogyo Shimbun Co., Ltd.), and are described in JP-A-8-108636 and JP-A-2002-264543 as curing technologies for curable silicone oils. The technique can be preferably used.
Note that abnormal transfer may occur in which the dye binder is taken on the receiving layer in the highlight portion of the monochromatic print. In addition, conventionally, addition polymerization type silicones generally proceed with a curing reaction in the presence of a catalyst, and almost all of iron group and platinum group 8 transition metal complexes are effective as curing catalysts. However, in general, platinum compounds are most efficient, and platinum catalysts which are platinum complexes soluble in silicone oil are usually preferably used. As an addition amount necessary for the reaction, about 1 to 100 ppm is sufficient.

  This platinum catalyst has a strong interaction with organic compounds containing multiple bonds, such as organic compounds containing N, P, S, etc., heavy metal ionic compounds such as Sn, Pb, Hg, Bi, As, acetylene groups, etc. When used together with the above compounds (catalyst poisons), the ability to hydrosilylate as a catalyst is lost, and the function as a curing catalyst is lost, so there is a drawback of causing poor curing of the silicone ("Silicone Handbook" Nikkan Kogyo). Newspaper company). Therefore, such a poorly cured addition polymerization type silicone does not exhibit any peeling performance even when used in the receiving layer. It is conceivable to use an isocyanate compound as a curing agent that reacts with active hydrogen, and this isocyanate compound and the organotin compound as a catalyst thereof are catalyst poisons of a platinum catalyst. Therefore, conventionally, the addition polymerization type silicone is not used in combination with an isocyanate compound, and thus is not used in combination with a modified silicone having active hydrogen that exhibits a peeling performance when cured with an isocyanate compound. .

  However, 1) the ratio of the reactive group equivalent of the curing agent that reacts with active hydrogen and the reactive group equivalent of both the thermoplastic resin and the modified silicone having active hydrogen is 1: 1 to 10: 1. 2) Addition polymerization type By setting the platinum catalyst amount with respect to silicone to 100 to 10,000 ppm as platinum atoms of the platinum catalyst, it is possible to prevent curing of the addition polymerization type silicone. When the reactive group equivalent of the curing agent that reacts with the active hydrogen of 1) is 1 or less, the curing amount of the active hydrogen-containing silicone and the active hydrogen of the thermoplastic resin is small, and good release performance is obtained. Absent. On the other hand, when the equivalent ratio is 10 or more, the usable time of the ink of the receiving layer coating liquid is short and cannot be used substantially. Further, when the platinum catalyst amount of 2) is 100 ppm or less, the activity is lost due to the catalyst poison, and when it is 10000 ppm or more, the ink usable time of the receiving layer coating liquid is short and cannot be used.

The coating amount of the receiving layer is preferably 0.5 to 10 g / m ² (in terms of solid content, hereinafter the coating amount in the present invention is a numerical value in terms of solid content unless otherwise specified).

<Release layer>
The cured modified silicone oil may be added to the release layer formed on the receiving layer without being added to the receiving layer. In this case, the receiving layer may be formed using one or more kinds of thermoplastic resins as described above, or a receiving layer to which silicone is added may be used. The release layer contains a curable modified silicone, and the type and usage of the silicone used are the same as those used for the receiving layer. Further, when a catalyst or a retarder is used, it is the same as that added to the receiving layer. The release layer may be formed only from silicone, or may be used as a binder resin by mixing with a compatible resin. The thickness of the release layer is about 0.001 to 1 g / m ^2.

  Fluorosurfactants include Fluorad FC-430 and FC-431 (both trade names, manufactured by 3M).

<Underlayer>
A base layer is preferably formed between the receptor layer and the support. For example, a white background adjustment layer, a charge adjustment layer, an adhesive layer, and a primer layer are formed. These layers can be formed in the same manner as described in, for example, Japanese Patent No. 3585599 and Japanese Patent No. 2925244.

<Insulation layer>
The heat insulating layer serves to protect the support from heat during heat transfer using a thermal head or the like. Moreover, since it has high cushioning properties, a thermal transfer image-receiving sheet with high printing sensitivity can be obtained even when paper is used as the substrate. The heat insulating layer may be one layer or two or more layers. The heat insulating layer is provided on the support side from the receptor layer.

(Hollow polymer)
In the image receiving sheet used in the present invention, the heat insulating layer contains a hollow polymer.
The hollow polymer in the present invention is a polymer particle having independent pores inside the particle. For example, [1] a dispersion medium such as water enters a partition formed by polystyrene, acrylic resin, styrene-acrylic resin or the like. After coating and drying, non-foamed hollow particles in which the dispersion medium in the particles evaporates outside the particles and the inside of the particles becomes hollow, [2] low boiling point liquids such as butane and pentane, polyvinylidene chloride, polyacrylonitrile Foam that is covered with a resin made of polyacrylic acid, polyacrylic acid ester, or a mixture or polymer thereof, and the inside of which is hollowed by the expansion of the low-boiling liquid inside the particles by heating after coating. Type microballoons, and [3] microballoons obtained by heating and foaming the above [2] in advance to form a hollow polymer.

The particle size of these hollow polymers is preferably 0.1 to 20 μm, more preferably 0.1 to 2 μm, still more preferably 0.1 to 1 μm, and particularly preferably 0.2 to 0.8 μm. If the size is too small, the hollowness tends to decrease and the desired heat insulating property cannot be obtained.If the size is too large, the particle diameter of the hollow polymer is too large for the film thickness of the heat insulating layer to obtain a smooth surface. This is because it becomes difficult to cause coating failure due to coarse particles.
The hollow ratio of the hollow polymer is preferably about 20 to 70%, more preferably 20 to 50%. This is because when the hollow ratio is less than 20%, sufficient heat insulation cannot be obtained, and when the hollow ratio is excessively high, the ratio of incomplete hollow particles increases within a preferable particle size range, and sufficient film strength is obtained. This is because it cannot be obtained.
The hollow ratio of the hollow polymer in the present invention is a value P calculated by the following formula (a) in a transmission image taken from a transmission micrograph of the hollow particles.

  In the above formula (a), Rai represents the equivalent circle diameter of the inner contour (indicating the hollow portion contour) of the two contours constituting the image of the specific particle i, and Rbi represents the image of the specific particle i. Of the two contours to be constructed, the equivalent circular diameter of the outer contour (indicating the particle outer shape) is represented, n represents the number of measured particles, and n ≧ 300.

  The glass transition temperature (Tg) of the hollow polymer is preferably 70 ° C. or higher, and more preferably 100 ° C. or higher. Two or more types of hollow polymers can be mixed and used as necessary.

  Such hollow polymers are commercially available, and specific examples of the above [1] include Law and Haas Ropaque 1055, Dainippon Ink Boncoat PP-1000, JSR SX866 (B), Nippon Zeon Nippon MH5055 (both are trade names). Specific examples of [2] include F-30 and F-50 (both trade names) manufactured by Matsumoto Yushi Seiyaku Co., Ltd. Specific examples of [3] include F-30E manufactured by Matsumoto Yushi Seiyaku Co., Ltd., EXPANSELL 461DE, 551DE, and 551DE20 (all trade names) manufactured by Nippon Ferrite Co., Ltd. Among these, the hollow polymer of the series [1] can be used more preferably.

  The heat insulating layer containing the hollow polymer preferably contains a water-dispersed resin or a water-soluble resin as a binder resin as a binder resin. Examples of the binder resin used in the present invention include acrylic resins, styrene-acrylic copolymers, polystyrene resins, polyvinyl alcohol resins, vinyl acetate resins, ethylene-vinyl acetate copolymers, vinyl chloride vinyl acetate copolymers, and styrene. Known resins such as butadiene copolymers, polyvinylidene chloride resins, cellulose derivatives, casein, starch, and gelatin can be used. In the present invention, it is particularly preferable to use gelatin. These resins can be used alone or in combination.

  The solid content of the hollow polymer in the heat insulating layer is preferably between 5 and 2000 parts by mass, and preferably between 5 and 1000 parts by mass when the solid content of the binder resin is 100 parts by mass. More preferably, it is more preferably between 5 and 400 parts by mass. Moreover, 1-70 mass% is preferable, and, as for the mass ratio which occupies with respect to the coating liquid of the solid content of a hollow polymer, 10-40 mass% is more preferable. If the ratio of the hollow polymer is too small, sufficient heat insulation cannot be obtained, and if the ratio of the hollow polymer is too large, the binding force between the hollow polymers is lowered, sufficient film strength cannot be obtained, and scratch resistance is obtained. Getting worse.

The image-receiving sheet used in the present invention does not contain a resin having no resistance to organic solvents in addition to the hollow polymer in the heat insulating layer. If the heat insulating layer contains a resin that is not resistant to organic solvents (pigment dyeing resin), the image bleeding after the image transfer increases, which is not preferable. This is because the dye-stainable resin and the hollow polymer exist in the heat insulating layer, so that the dye dyed on the receiving layer after the transfer moves over time through the adjacent heat-insulating layer. it is conceivable that.
Here, “not resistant to organic solvent” means that the solubility in an organic solvent (methyl ethyl ketone, ethyl acetate, benzene, toluene, xylene, etc.) is 1% by mass or less, preferably 0.5% by mass or less. Say. For example, the polymer latex is included in “resin not resistant to organic solvent”.

  The thickness of the heat insulating layer containing the hollow polymer is preferably 5 to 50 μm, and more preferably 5 to 40 μm.

The porosity of the heat insulating layer calculated from the thickness of the heat insulating layer containing the hollow polymer and the solid coating amount of the heat insulating layer containing the hollow polymer is preferably 10 to 70%, and more preferably 15 to 60%. When the porosity of the heat insulating layer is less than 10%, sufficient heat insulating properties cannot be obtained, and when it is 70% or more, the binding force between the hollow polymers is lowered, and sufficient film strength cannot be obtained, and the scratch resistance is deteriorated.
In the present invention, the porosity of the heat insulating layer is a value V calculated by the following equation (b).

  In the above formula (b), L represents the film thickness of the heat insulating layer, gi represents the solid coating amount of the specific material i constituting the heat insulating layer, and di represents the specific gravity of the specific material i. Here, when di represents the specific gravity of the hollow polymer, di represents the specific gravity of the wall material of the hollow polymer.

(Hydrophilic polymer)
The heat insulating layer contains a hydrophilic polymer (hereinafter also referred to as a water-soluble polymer or a water-soluble polymer). Water-soluble polymers that can be used in the present invention include natural polymers (polysaccharides, microorganisms, animals), semi-synthetic polymers (cellulose, starch, alginic acid), and synthetic polymers (vinyl, Others), synthetic polymers such as polyvinyl alcohol described below, and natural or semi-synthetic polymers made from plant-derived cellulose or the like correspond to water-soluble polymers that can be used in the present invention.
Here, the water-soluble polymer may be dissolved in an amount of 0.05 g or more with respect to 100 g of water at 20 ° C., more preferably 0.1 g or more, still more preferably 0.5 g or more, and particularly preferably 1 g or more.

Of the water-soluble polymers that can be used in the present invention, natural polymers and semi-synthetic polymers will be described in detail. Plant polysaccharides include gum arabic, κ-carrageenan, ι-carrageenan, λ-carrageenan, guar gum (such as Supercol from Squall), locust bean gum, pectin, tragacanth, corn starch (Purity- from National Starch & Chemical Co.) 21), phosphorylated starch (National 78-1898 made by National Starch & Chemical Co.), and other microbial polysaccharides such as xanthan gum (Kelco Keltrol T, etc.) and dextrin (Nadex360 made by National Starch & Chemical Co., etc.) Examples of animal natural polymers include gelatin (such as Crodyne B419 from Croda), casein, sodium chondroitin sulfate (such as Cromoist CS from Croda), and the like (all are trade names). Cellulose systems include ethyl cellulose (ICI Cellofas WLD, etc.), carboxymethyl cellulose (Daicel CMC, etc.), hydroxyethyl cellulose (Daicel HEC, etc.), hydroxypropyl cellulose (Aqualon Klucel, etc.), methyl cellulose (Henkel Viscontran, etc.), Examples include nitrocellulose (such as Isopropyl Wet from Hercules) and cationized cellulose (such as Crodacel QM from Croda). Other starches such as phosphorylated starch (National Starch &Chemical's National 78-1898) and alginic acid are sodium alginate (such as Kelco's Keltone) and propylene glycol alginate. Hi-care1000, etc.) and sodium hyaluronate (Hyalure, etc. from Lifecare Biomedial) are included (all are trade names).
In the present invention, gelatin is one of the preferred embodiments. The gelatin used in the present invention may have a molecular weight of 10,000 to 1,000,000. Gelatin used in the present invention may contain anions such as Cl ⁻ , SO ₄ ²⁻ , and cations such as Fe ²⁺ , Ca ²⁺ , Mg ²⁺ , Sn ²⁺ and Zn ^2+. It may be included. It is preferable to add gelatin dissolved in water.

Of the water-soluble polymers that can be used in the present invention, synthetic polymers will be described in detail.
Examples of the acrylic system include sodium polyacrylate, polyacrylic acid copolymer, polyacrylamide, polyacrylamide copolymer, polydiethylaminoethyl (meth) acrylate quaternary salt or a copolymer thereof, and the vinyl system includes polyvinylpyrrolidone, Polyvinyl pyrrolidone copolymer, polyvinyl alcohol, etc. include polyethylene glycol, polypropylene glycol, polyisopropyl acrylamide, polymethyl vinyl ether, polyethylene imine, polystyrene sulfonic acid or copolymer thereof, naphthalene sulfonic acid condensate salt, polyvinyl sulfonic acid Or a copolymer thereof, polyacrylic acid or a copolymer thereof, acrylic acid or a copolymer thereof, a maleic acid copolymer, a maleic acid monoester copolymer, an acryloylme Propane sulfonic acid or its copolymer, etc.), polydimethyldiallylammonium chloride or its copolymer, polyamidine or its copolymer, polyimidazoline, dicyanciamide condensate, epichlorohydrin-dimethylamine condensate, polyacrylamide Hoffman Decomposed product, water-soluble polyester (Plus coat Z-221, Z-446, Z-561, Z-450, Z-565, Z-850, Z-3308, RZ-105, RZ-570, manufactured by Kyodo Chemical Co., Ltd.) , Z-730, RZ-142 (both are trade names)).

Further, it has a superabsorbent polymer described in US Pat. No. 4,960,681, JP-A-62-245260, etc., that is, —COOM or —SO ₃ M (M is a hydrogen atom or an alkali metal). A homopolymer of vinyl monomers or a copolymer of these vinyl monomers or other vinyl monomers (for example, sodium methacrylate, ammonium methacrylate, Sumikagel L-5H (trade name) manufactured by Sumitomo Chemical Co., Ltd.) should also be used. Can do.

Of the water-soluble synthetic polymers that can be used in the present invention, polyvinyl alcohols are preferred.
Hereinafter, polyvinyl alcohol will be described in more detail.
As a complete saponified product, PVA-105 [polyvinyl alcohol (PVA) content 94.0% by mass or more, saponification degree 98.5 ± 0.5 mol%, sodium acetate content 1.5% by mass or less, volatile content 5 0.0 mass% or less, viscosity (4 mass%, 20 ° C.) 5.6 ± 0.4 CPS], PVA-110 [PVA content 94.0 mass%, saponification degree 98.5 ± 0.5 mol%, acetic acid Sodium content 1.5% by mass, volatile matter 5.0% by mass, viscosity (4% by mass, 20 ° C.) 11.0 ± 0.8 CPS], PVA-117 [PVA content 94.0% by mass, saponification degree 98.5 ± 0.5 mol%, sodium acetate content 1.0 mass%, volatile content 5.0 mass%, viscosity (4 mass%, 20 ° C.) 28.0 ± 3.0 CPS],

PVA-117H [PVA content 93.5% by mass, saponification degree 99.6 ± 0.3 mol%, sodium acetate content 1.85% by mass, volatile matter 5.0% by mass, viscosity (4% by mass, 20% ° C) 29.0 ± 3.0 CPS], PVA-120 [PVA content 94.0 mass%, saponification degree 98.5 ± 0.5 mol%, sodium acetate content 1.0 mass%, volatile content 5. 0% by mass, viscosity (4% by mass, 20 ° C.) 39.5 ± 4.5 CPS], PVA-124 [PVA content 94.0% by mass, saponification degree 98.5 ± 0.5 mol%, sodium acetate contained 1.0 mass%, volatile matter 5.0 mass%, viscosity (4 mass%, 20 ° C.) 60.0 ± 6.0 CPS],

PVA-124H [PVA content 93.5% by mass, saponification degree 99.6 ± 0.3 mol%, sodium acetate content 1.85% by mass, volatile matter 5.0% by mass, viscosity (4% by mass, 20% ° C) 61.0 ± 6.0 CPS], PVA-CS [PVA content 94.0 mass%, saponification degree 97.5 ± 0.5 mol%, sodium acetate content 1.0 mass%, volatile content 5. 0 mass%, viscosity (4 mass%, 20 ° C.) 27.5 ± 3.0 CPS], PVA-CST [PVA content 94.0 mass%, saponification degree 96.0 ± 0.5 mol%, sodium acetate contained 1.0 mass%, volatile matter 5.0 mass%, viscosity (4 mass%, 20 ° C.) 27.0 ± 3.0 CPS], PVA-HC [PVA content 90.0 mass%, saponification degree 99. 85 mol% or more, sodium acetate content 2.5 mass%, volatile content 8.5 mass%, viscosity (4 mass%, 20 ℃) 25.0 ± 3.5CPS] (trade names, available from Kuraray Co.), etc.,

As a partially saponified product, PVA-203 [PVA content 94.0% by mass, saponification degree 88.0 ± 1.5 mol%, sodium acetate content 1.0% by mass, volatile matter 5.0% by mass, viscosity (4 mass%, 20 ° C.) 3.4 ± 0.2 CPS], PVA-204 [PVA content 94.0 mass%, saponification degree 88.0 ± 1.5 mol%, sodium acetate content 1.0 mass %, Volatile matter 5.0 mass%, viscosity (4 mass%, 20 ° C.) 3.9 ± 0.3 CPS], PVA-205 [PVA content 94.0 mass%, saponification degree 88.0 ± 1.5 Mol%, sodium acetate content 1.0% by mass, volatile matter 5.0% by mass, viscosity (4% by mass, 20 ° C.) 5.0 ± 0.4 CPS],

PVA-210 [PVA content 94.0% by mass, saponification degree 88.0 ± 1.0 mol%, sodium acetate content 1.0% by mass, volatile matter 5.0% by mass, viscosity (4% by mass, 20% ° C) 9.0 ± 1.0 CPS], PVA-217 [PVA content 94.0% by mass, saponification degree 88.0 ± 1.0 mol%, sodium acetate content 1.0% by mass, volatile content 5. 0% by mass, viscosity (4% by mass, 20 ° C.) 22.5 ± 2.0 CPS], PVA-220 [PVA content 94.0% by mass, saponification degree 88.0 ± 1.0 mol%, sodium acetate contained 1.0 mass%, volatile matter 5.0 mass%, viscosity (4 mass%, 20 ° C.) 30.0 ± 3.0 CPS],

PVA-224 [PVA content 94.0% by mass, saponification degree 88.0 ± 1.5 mol%, sodium acetate content 1.0% by mass, volatile matter 5.0% by mass, viscosity (4% by mass, 20% ° C) 44.0 ± 4.0 CPS], PVA-228 [PVA content 94.0% by mass, saponification degree 88.0 ± 1.5 mol%, sodium acetate content 1.0% by mass, volatile content 5. 0 mass%, viscosity (4 mass%, 20 ° C.) 65.0 ± 5.0 CPS], PVA-235 [PVA content 94.0 mass%, saponification degree 88.0 ± 1.5 mol%, sodium acetate contained 1.0 mass%, volatile matter 5.0 mass%, viscosity (4 mass%, 20 ° C.) 95.0 ± 15.0 CPS],

PVA-217EE [PVA content 94.0% by mass, saponification degree 88.0 ± 1.0 mol%, sodium acetate content 1.0% by mass, volatile matter 5.0% by mass, viscosity (4% by mass, 20% ° C) 23.0 ± 3.0 CPS], PVA-217E [PVA content 94.0 mass%, saponification degree 88.0 ± 1.0 mol%, sodium acetate content 1.0 mass%, volatile content 5. 0 mass%, viscosity (4 mass%, 20 ° C.) 23.0 ± 3.0 CPS], PVA-220E [PVA content 94.0 mass%, saponification degree 88.0 ± 1.0 mol%, sodium acetate contained 1.0 mass%, volatile matter 5.0 mass%, viscosity (4 mass%, 20 ° C.) 31.0 ± 4.0 CPS],

PVA-224E [PVA content 94.0% by mass, saponification degree 88.0 ± 1.0 mol%, sodium acetate content 1.0% by mass, volatile matter 5.0% by mass, viscosity (4% by mass, 20% ° C) 45.0 ± 5.0 CPS], PVA-403 [PVA content 94.0 mass%, saponification degree 80.0 ± 1.5 mol%, sodium acetate content 1.0 mass%, volatile content 5. 0 mass%, viscosity (4 mass%, 20 ° C.) 3.1 ± 0.3 CPS], PVA-405 [PVA content 94.0 mass%, saponification degree 81.5 ± 1.5 mol%, sodium acetate contained 1.0 mass%, volatile matter 5.0 mass%, viscosity (4 mass%, 20 ° C.) 4.8 ± 0.4 CPS],

PVA-420 [PVA content 94.0% by mass, saponification degree 79.5 ± 1.5 mol%, sodium acetate content 1.0% by mass, volatile matter 5.0% by mass], PVA-613 [PVA-containing Rate 94.0% by mass, degree of saponification 93.5 ± 1.0 mol%, sodium acetate content 1.0% by mass, volatile matter 5.0% by mass, viscosity (4% by mass, 20 ° C.) 16.5 ± 2.0 CPS], L-8 [PVA content 96.0 mass%, saponification degree 71.0 ± 1.5 mol%, sodium acetate content 1.0 mass% (ash content), volatile content 3.0 mass% Viscosity (4% by mass, 20 ° C.) 5.4 ± 0.4 CPS] (all are trade names manufactured by Kuraray Co., Ltd.).

  In addition, said measured value is calculated | required according to JISK-6726-1977.

  As for the modified polyvinyl alcohol, those described in Koichi Nagano et al., “Poval” (published by Kobunshi Shuppankai) are used. There is modification by cation, anion, -SH compound, alkylthio compound, silanol.

  As such modified polyvinyl alcohol (modified PVA), C-118, C-318, C-318-2A, C-506 (all are trade names manufactured by Kuraray Co., Ltd.), HL polymer as C polymer. HL-12E, HL-1203 (all are trade names manufactured by Kuraray Co., Ltd.), HM polymer is HM-03, HM-N-03 (all are trade names manufactured by Kuraray Co., Ltd.), KL-118, KL-318, KL-506, KM-118T, KM-618 (all are trade names manufactured by Kuraray Co., Ltd.) as the K polymer, and M-115 (manufactured by Kuraray Co., Ltd.) as the M polymer. (Trade name), MP-102, MP-202, MP-203 (all are trade names manufactured by Kuraray Co., Ltd.) as MP polymers, MPK-1, MPK-2, MPK-3, PK-4, MPK-5, MPK-6 (all are trade names manufactured by Kuraray Co., Ltd.), R polymer as R-1130, R-2105, R-2130 (all are manufactured by Kuraray Co., Ltd.) And V-2250 (trade name, manufactured by Kuraray Co., Ltd.).

  Polyvinyl alcohol can be adjusted in viscosity or stabilized by a small amount of solvent or inorganic salt added to the aqueous solution. For details, refer to the above document, Koichi Nagano et al., “Poval”, Polymer Issued by the publisher, pages 144 to 154 can be used. As a typical example, it is possible to improve the coating surface quality by containing boric acid, which is preferable. The addition amount of boric acid is preferably 0.01 to 40% by mass with respect to polyvinyl alcohol.

  Suitable binders for use in the thermal insulation layer are transparent or translucent and generally colorless and are natural resins, polymers and copolymers, synthetic resins, polymers and copolymers, and other media forming films such as rubbers, polyvinyl alcohols, Hydroxyethyl celluloses, cellulose acetates, cellulose acetate butyrates, polyvinyl pyrrolidones, starches, polyacrylic acids, polymethyl methacrylic acids, polyvinyl chlorides, polymethacrylic acids, styrene-maleic anhydride copolymers, styrene- Acrylonitrile copolymers, styrene-butadiene copolymers, polyvinyl acetals (eg, polyvinyl formal and polyvinyl butyral), polyesters, polyurethanes, phenoxy resins, polyvinylidene chlorides Polyepoxides, polycarbonates, polyvinyl acetates, polyolefins, cellulose esters, and polyamides such water-soluble.

In the present invention, the water-soluble polymer is preferably polyvinyl alcohol or gelatin, and most preferably gelatin.
The amount of the water-soluble polymer added to the heat insulating layer is preferably 1 to 75% by mass and more preferably 1 to 50% by mass with respect to the entire heat insulating layer.
When gelatin is used for the heat insulating layer, the amount of gelatin in the coating solution is preferably 0.5 to 14% by mass, and particularly preferably 1 to 6% by mass. The coating amount of the hollow polymer in the heat insulation layer is preferably ^{1~100g / m 2, 5~20g / m} 2 is more preferable.

Moreover, it is preferable that the water-soluble polymer contained in the heat insulation layer is crosslinked with a hardener. The preferred range of the crosslinking agent that can be preferably used and the amount of use thereof is the same as described above.
The water-soluble polymer in the heat-insulating layer varies depending on the type of hardener, but is preferably 0.1 to 20% by mass crosslinked with respect to the water-soluble polymer, and is 1 to 10% by mass crosslinked. It is more preferable.

  In this invention, it is also a preferable form to use the water-soluble polymer used in a heat insulation layer also for the said receiving layer, and the preferable polymer of these water-soluble polymers is the same as a heat insulation layer.

(Hardener)
The hardening agent used in the present invention as a crosslinking agent (also referred to as a compound capable of crosslinking a water-soluble polymer or a crosslinking agent) is a coating layer of an image receiving sheet (for example, a receiving layer, a heat insulating layer, an undercoat layer, etc.). Can be added inside. Particularly preferred is the case of using it for a layer using a water-soluble polymer.
Examples of the hardening agent that can be used in the present invention include H-1,4,6,8,14 on page 17 of JP-A-1-214845, column 13 to U.S. Pat. No. 4,618,573. 23 compounds (H-1 to 54) represented by formulas (VII) to (XII), compounds (H-1 to 76) represented by formula (6) at the lower right of JP-A-2-214852, page 8, In particular, H-14 and the compounds described in claim 1 of US Pat. No. 3,325,287 are preferably used. Examples of hardeners are US Pat. No. 4,678,739, column 41, US Pat. No. 4,791,042, JP-A-59-116655, JP-A-62-245261, and JP-A-61-18942. And the hardening agent described in JP-A-4-218444 or the specification thereof. More specifically, aldehyde hardeners (formaldehyde, etc.), aziridine hardeners, epoxy hardeners, vinyl sulfone hardeners (N, N′-ethylene-bis (vinylsulfonylacetamide) Ethane), N-methylol hardeners (dimethylolurea, etc.), boric acid, metaboric acid, or polymer hardeners (compounds described in JP-A-62-234157).
Preferably, a vinyl sulfone type hardener and chlorotriazines are used.
More preferable hardeners in the present invention are compounds represented by the following general formula (B) or (C).
General formula (B)
_{(CH 2 = CH-SO 2} ) n-L
General formula (C)
_{(X-CH 2 -CH 2 -SO} 2) n-L
In general formulas (B) and (C), X represents a halogen atom, and L represents an n-valent organic linking group. When the compound represented by formula (B) or (C) is a low molecular compound, n represents an integer of 1 to 4. In the case of a polymer compound, L is an organic linking group containing a polymer chain, and n is in the range of 10 to 1000.

  In the general formulas (B) and (C), X is preferably a chlorine atom or a bromine atom, more preferably a bromine atom. n is an integer of 1 to 4, preferably an integer of 2 to 4, more preferably an integer of 2 to 3, and most preferably 2.

  L represents an n-valent organic group, preferably an aliphatic hydrocarbon group, an aromatic hydrocarbon group or a heterocyclic group, and these groups are ether bond, ester bond, amide bond, sulfonamide bond, urea bond, It may be further connected with a urethane bond or the like. These groups may have a substituent, such as a halogen atom, alkyl group, aryl group, heterocyclic group, hydroxyl group, alkoxy group, aryloxy group, alkylthio group, arylthio group, acyloxy group, alkoxycarbonyl. Groups, carbamoyloxy groups, acyl groups, acyloxy groups, acylamino groups, sulfonamido groups, carbamoyl groups, sulfamoyl groups, sulfonyl groups, phosphoryl groups, carboxyl groups, sulfo groups, etc., halogen atoms, alkyl groups, hydroxy groups, Alkoxy groups, aryloxy groups and acyloxy groups are preferred.

  Specific examples of the vinyl sulfone hardener include the following (VS-1) to (VS-27), but are not limited to these in the present invention.

These hardeners can be obtained by referring to the method described in US Pat. No. 4,173,481.
As the chlorotriazine hardener, a 1,3,5-triazine compound in which at least one chloro atom is substituted at the 2-position, 4-position or 6-position is preferable.
More preferred are those in which 2 or 3 chlorine atoms are substituted at the 2nd, 4th or 6th position. At least one chlorine atom may be substituted at the 2-position, 4-position or 6-position, and a group other than a chlorine atom may be substituted at the remaining positions. Examples of these groups include a hydrogen atom, a bromine atom, Fluorine atom, iodine atom, alkyl group, alkenyl group, alkynyl group, cycloalkyl group, cycloalkenyl group, aryl group, heterocyclic group, hydroxy group, nitro group, cyano group, amino group, hydroxylamino group, alkylamino group, Arylamino group, heterocyclic amino group, acylamino group, sulfonamido group, carbamoyl group, sulfamoyl group, sulfo group, carboxyl group, alkoxy group, alkenoxy group, aryloxy group, heterocyclic oxy group, acyl group, acyloxy group, alkyl Or arylsulfonyl group, alkyl or arylsulfinyl group, alkyl Ku is arylsulfonyloxy group, a mercapto group, an alkylthio group, an alkenylthio group, an arylthio group, a heterocyclic thio group, such as alkyloxy or aryloxy carbonyl group.
Specific examples of the chlorotriazine hardener include 4,6-dichloro-2-hydroxy-1,3,5-triazine or its Na salt, 2-chloro-4,6-diphenoxytriazine, 2-chloro. -4,6-bis [2,4,6-trimethylphenoxy] triazine, 2-chloro-4,6-diglycidoxy-1,3,5-triazine, 2-chloro-4- (n-butoxy) -6 Glycidoxy-1,3,5-triazine, 2-chloro-4- (2,4,6-trimethylphenoxy) -6-glycidoxy-1,3,5-triazine, 2-chloro-4- (2-chloroethoxy ) -6- (2,4,6-trimethylphenoxy) 1,3,5-triazine, 2-chloro-4- (2-bromoethoxy) -6- (2,4,6-trimethylphenoxy) -1, 3,5-tri 2-chloro-4- (2-di-n-butylphosphatoethoxy) -6- (2,4,6-trimethylphenoxy) -1,3,5-triazine, 2-chloro-4- (2 -Di-n-butylphosphatoethoxy) -6- (2,6-xylenoxy) -1,3,5-triazine and the like, but not limited thereto.
Such a compound can be easily produced by reacting cyanuric chloride (that is, 2,4,6-trichlorotriazine) with a hydroxy compound, a thio compound or an amino compound corresponding to a substituent on the heterocyclic ring.

  These hardeners are used in an amount of 0.001 to 1 g, preferably 0.005 to 0.5 g, per 1 g of water-soluble polymer.

<Underlayer>
An undercoat layer may be formed between the receiving layer and the heat insulating layer. For example, a white background adjusting layer, a charge adjusting layer, an adhesive layer, and a primer layer are formed. About these layers, it can be set as the structure similar to what was described, for example in patent 3585599, patent 2925244, etc.

<Support>
In the present invention, any support may be used, and a known support is preferable for the thermal transfer image-receiving sheet, but a water-resistant support is particularly preferably used. By using a water-resistant support, it is possible to prevent moisture from being absorbed into the support, and to prevent a change in performance of the receiving layer over time. As the water-resistant support, for example, coated paper or laminated paper can be used.

-Coated paper-
The coated paper is a paper obtained by coating various sheets of resin, rubber latex, or polymer material on one side or both sides of a sheet such as a base paper, and the coating amount varies depending on the application. Examples of such coated paper include art paper, cast coated paper, Yankee paper, and the like.

  As the resin applied to the surface of the base paper or the like, it is appropriate to use a thermoplastic resin. Examples of such a thermoplastic resin include the following thermoplastic resins (a) to (h).

(A) Polyolefin resins such as polyethylene resins and polypropylene resins, copolymer resins of olefins such as ethylene and propylene and other vinyl monomers, acrylic resins, and the like.
(B) A thermoplastic resin having an ester bond. For example, a dicarboxylic acid component (these dicarboxylic acid components may be substituted with a sulfonic acid group, a carboxyl group, etc.) and an alcohol component (these alcohol components may be substituted with a hydroxyl group, etc.) Polyester resin, polymethyl methacrylate, polybutyl methacrylate, polymethyl acrylate, polybutyl acrylate and other polyacrylate resin or polymethacrylate resin, polycarbonate resin, polyvinyl acetate resin, styrene acrylate resin, styrene -Methacrylic acid ester copolymer resin, vinyl toluene acrylate resin, etc. are mentioned.
Specific examples include those described in JP-A Nos. 59-101395, 63-7971, 63-7972, 63-7773, and 60-294862. it can.
Commercially available products include Byron 290, Byron 200, Byron 280, Byron 300, Byron 103, Byron GK-140, Byron GK-130 manufactured by Toyobo Co., Ltd., Tufton NE-382, Tufton manufactured by Kao Corporation U-5, ATR-2009, ATR-2010; Elitel UE3500, UE3210, XA-8153, KZA-7049, KZA-1449 manufactured by Unitika Ltd. Polyester TP-220, R manufactured by Nippon Synthetic Chemical Co., Ltd. -188; various types of thermoplastic resins of the Hiros series manufactured by Seiko Chemical Industry Co., Ltd. (all trade names).

(C) Polyurethane resin etc. are mentioned.
(D) Polyamide resin, urea resin, etc. are mentioned.
(E) Polysulfone resin and the like.
(F) Polyvinyl chloride resin, polyvinylidene chloride resin, vinyl chloride-vinyl acetate copolymer resin, vinyl chloride-vinyl propionate copolymer resin, and the like.
(G) Cellulose resins, such as polyol resin, ethyl cellulose resin, cellulose acetate resin, etc., such as polyvinyl butyral.
(H) Polycaprolactone resin, styrene-maleic anhydride resin, polyacrylonitrile resin, polyether resin, epoxy resin, phenol resin and the like.
In addition, the said thermoplastic resin may be used individually by 1 type, and may use 2 or more types together.

  Further, the thermoplastic resin may contain pigments or dyes such as brighteners, conductive agents, fillers, titanium oxide, ultramarine blue, and carbon black as required.

-Laminated paper-
The laminated paper is a paper obtained by laminating various resins, rubber or polymer sheets or films on a sheet such as a base paper. Examples of the laminate material include polyolefin, polyvinyl chloride, polyethylene terephthalate, polystyrene, polymethacrylate, polycarbonate, polyimide, triacetyl cellulose, and the like. These resins may be used alone or in combination of two or more.

  In general, the polyolefin is often formed using low density polyethylene, but in order to improve the heat resistance of the support, polypropylene, a blend of polypropylene and polyethylene, high density polyethylene, high density polyethylene and low density polyethylene, It is preferable to use a blend of In particular, it is most preferable to use a blend of high-density polyethylene and low-density polyethylene from the viewpoint of cost, suitability for lamination, and the like.

The blend of the high density polyethylene and the low density polyethylene is used, for example, in a blend ratio (mass ratio) of 1/9 to 9/1. The blend ratio is preferably 2/8 to 8/2, and more preferably 3/7 to 7/3. When forming a thermoplastic resin layer on both surfaces of the support, the back surface of the support is preferably formed using, for example, high-density polyethylene or a blend of high-density polyethylene and low-density polyethylene. The molecular weight of polyethylene is not particularly limited, but the melt index is 1.0 to 40 g / 10 min for both high-density polyethylene and low-density polyethylene and has extrudability. preferable.
In addition, you may perform the process which gives white reflectivity to these sheets or films. Examples of such a treatment method include a method of blending a pigment such as titanium oxide in these sheets or films.

  The thickness of the support is preferably 25 μm to 300 μm, more preferably 50 μm to 260 μm, and still more preferably 75 μm to 220 μm. Various stiffnesses can be used according to the purpose, and the support for a photographic image receiving sheet for electrophotography is close to a support for color silver halide photography. Those are preferred.

<Curl adjustment layer>
If the support is exposed as it is, the heat-sensitive transfer image-receiving sheet may be curled due to the humidity and temperature in the environment. Therefore, it is preferable to form a curl adjusting layer on the back side of the support. The curl adjusting layer not only prevents the image receiving sheet from curling but also serves as a waterproof. For the curl adjusting layer, polyethylene laminate, polypropylene laminate, or the like is used. Specifically, it can be formed in the same manner as described in, for example, JP-A-61-110135 and JP-A-6-202295.

<Writing layer / Charge adjusting layer>
An inorganic oxide colloid, an ionic polymer, or the like can be used for the writing layer and the charge adjusting layer. As the antistatic agent, for example, a cationic antistatic agent such as a quaternary ammonium salt or a polyamine derivative, an anionic antistatic agent such as an alkyl phosphate, or a nonionic antistatic agent such as a fatty acid ester can be used. . Specifically, for example, it can be formed in the same manner as described in Japanese Patent No. 3585585.

The method for producing the thermal transfer image receiving sheet of the present invention will be described below.
The heat-sensitive transfer image-receiving sheet of the present invention can be formed by simultaneously applying at least one receiving layer, intermediate layer and heat insulating layer on a support.
When producing a multi-layer image receiving sheet comprising a plurality of layers having different functions (such as a bubble layer, a heat insulating layer, an intermediate layer, and a receiving layer) on a support, JP-A Nos. 2004-106283 and 2004-181888 are disclosed. In addition, it is known that each layer is sequentially coated as disclosed in each publication such as JP-A 2004-345267, or the layers are previously applied on a support and bonded together. On the other hand, it is known in the photographic industry that productivity is greatly improved, for example, by applying a plurality of layers simultaneously. For example, U.S. Pat. Nos. 2,761,791, 2,681,234, 3,508,947, 4,457,256, 3,993,019, JP 63-54975, JP-A-61-278848, 55-86557, 52-31727, 55-142565, 50-43140, 63-80872, 54-54020, Special Publications and specifications of Kaihei 5-104061, 5-127305, JP-B 49-7050, and Edgar B. Gutoff et al., "Coating and Drying Defects: Troubleshooting Operating Problems", John Wiley & Sons, 1995, 101. There are known so-called slide coating (slide coating method) and curtain coating (curtain coating method) described on pages ~ 103.
In the present invention, the simultaneous multi-layer coating is used for manufacturing a multi-layer image-receiving sheet, whereby productivity can be greatly improved and image defects can be greatly reduced.

In the present invention, the plurality of layers are composed mainly of a resin. The coating solution for forming each layer is preferably water-dispersed latex. The solid content mass of the latex resin in the coating solution of each layer is preferably in the range of 5 to 80%, particularly preferably in the range of 20 to 60%. The average particle size of the resin contained in the water-dispersed latex is 5 μm or less and particularly preferably 1 μm or less. The water-dispersed latex may contain a known additive such as a surfactant, a dispersant, and a binder resin as necessary.
In the present invention, it is preferable to form a laminate of a plurality of layers on a support by the method described in US Pat. No. 2,761,791 and then solidify immediately. As an example, in the case of a multilayer structure solidified by a resin, it is preferable to quickly raise the temperature after forming a plurality of layers on the support. When a binder that gels at a low temperature such as gelatin is included, it may be preferable to quickly lower the temperature after forming a plurality of layers on the support.
The coating amount of a coating solution per one layer constituting the multilayer in the present invention in the range of 1g / m ² ~500g / m ² is preferred. The number of layers in the multilayer configuration can be arbitrarily selected as 2 or more. The receiving layer is preferably provided as the layer furthest away from the support.

Next, the thermal transfer sheet (ink sheet) used in the present invention will be described.
2) Thermal transfer sheet In the thermal transfer image formation, the ink sheet used together with the thermal transfer image receiving sheet described above is provided with a thermal transfer layer (hereinafter also referred to as a dye layer) containing a diffusion transfer dye on a support. Is. The dye layer is applied by a general method such as roll coating, bar coating, gravure coating, or gravure reverse coating.
The support is not particularly limited, for example, thin paper such as glassine paper, condenser paper, paraffin paper, or polyester, polypropylene, cellophane, polycarbonate, cellulose acetate, polyethylene, polyvinyl chloride, polystyrene, nylon, polyimide, polychlorinated Examples thereof include plastics such as vinylidene and ionomer, and a base film obtained by combining these with the paper. Although the thickness of a support body can be suitably changed according to material so that the intensity | strength, heat resistance, etc. may become suitable, Preferably it is 3-100 micrometers.

The magenta thermal transfer layer (magenta dye layer) of the ink sheet used in the present invention contains at least one compound represented by the following general formula (M) as a magenta dye, and the cyan thermal transfer layer (cyan dye layer) contains Contains only a compound represented by the following general formula (C) as a cyan dye. Preferably, the yellow thermal transfer layer (yellow dye layer) contains at least one compound represented by any one of the following general formulas (YA) to (YE).
The following compounds are described.

In the general formula (M), D ^{1 to} D ⁵ are each independently a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an aryl group, an aryloxy group, a cyano group, an acylamino group, a sulfonylamino group, a ureido group, an alkoxy group. Represents a carbonylamino group, an alkylthio group, an arylthio group, an alkoxycarbonyl group, a carbamoyl group, a sulfamoyl group, a sulfonyl group, an acyl group or an amino group, and D ⁶ and D ⁷ each independently represent a hydrogen atom, an alkyl group or an aryl group. . D ⁶ and D ⁷ may be bonded to each other to form a ring, or D ³ and D ⁶ or / and D ⁴ and D ⁷ may be bonded to each other to form a ring. X, Y and Z represent ═C (D ⁸ ) — or a nitrogen atom. Here, D ⁸ represents a hydrogen atom, an alkyl group, an aryl group, an alkoxy group, an aryloxy group or an amino group. When X and Y are = C (D ⁸ )-, or when Y and Z are = C (D ⁸ )-, two D ⁸ are bonded to each other to form a saturated or unsaturated carbocyclic ring. Also good. Each of these groups may further have a substituent.

In the general formula (C), D ^{9 to} D ¹⁶ are each independently a hydrogen atom, halogen atom, alkyl group, alkoxy group, aryl group, aryloxy group, cyano group, acylamino group, sulfonylamino group, ureido group, alkoxy group. Represents a carbonylamino group, an alkylthio group, an arylthio group, an alkoxycarbonyl group, a carbamoyl group, a sulfamoyl group, a sulfonyl group, an acyl group or an amino group, and D ¹⁷ and D ¹⁸ each independently represent a hydrogen atom, an alkyl group or an aryl group. . D ¹⁷ and D ¹⁸ may be bonded to each other to form a ring, or D ¹⁴ and D ¹⁷ or / and D ¹⁵ and D ¹⁸ may be bonded to each other to form a ring. Each of these groups may further have a substituent.

In the general formula (YA), R ¹¹ represents a monovalent substituent, R ¹² represents a hydrogen atom or a monovalent substituent, and Ar ¹ represents a group selected from the group (1) of the following heterocyclic group. X represents an atomic group necessary for ring formation.

（ヘテロ環基の群（１）において、Ｒ⁶¹、Ｒ⁶²、Ｒ⁶³、Ｒ⁶⁴およびＲ⁶⁵は各々独立に水素原子または置換基を表す。）

(In the heterocyclic group (1), R ⁶¹ , R ⁶² , R ⁶³ , R ⁶⁴ and R ⁶⁵ each independently represents a hydrogen atom or a substituent.)

In the general formula (YB), R ¹ , R ² , R ³ , R ⁴ and R ⁶ each independently represent a hydrogen atom or a monovalent substituent, and R ⁵ represents a monovalent substituent.

In the general formula (YC), R ^A , R ^B , R ^C , R ^D and R ^E are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group, an alkoxy group, an alkoxyalkoxy Represents a group, an alkoxycarbonyl group, a thioalkoxy group, an alkylsulfonyl group, an amino group, a substituted or unsubstituted phenoxy group, or a substituted or unsubstituted thiophenoxy group. R ^F and R ^G are each independently a hydrogen atom, an alkyl group, an alkoxyalkyl group, a cycloalkyl group, an allyl group, an aryl group that may have a substituent, an aralkyl group, a furfuryl group, a tetrahydrofurfuryl group, or Represents a hydroxyalkyl group. Each of these groups may further have a substituent.

In the general formula (YD), R ^1A represents an allyl group or an alkyl group, R ^2A represents a substituted or unsubstituted alkyl group or an aryl group, and A represents —CH ₂ —, —CH ₂ CH ₂ —, —CH ₂ CH ₂ O—, —CH ₂ CH ₂ OCH ₂ — or —CH ₂ CH ₂ OCH ₂ CH ₂ — is represented, and R ^3A represents an alkyl group. Each of these groups may further have a substituent.

In General Formula (YE), R ^1B and R ^2B each independently represent a hydrogen atom, an optionally substituted alkyl group, an allyl group, an optionally substituted aryl group, or an optionally substituted cyclo Represents an alkyl group, and R ^3B represents a hydrogen atom, an optionally substituted alkyl group, an NR ^5C R ^6C group, an optionally substituted alkoxy group, an optionally substituted alkoxycarbonyl group, or an optionally substituted group. Represents a good aryl group or a C (O) NR ^5D R ^6D group, wherein R ^4B , R ^5C , R ^5D , R ^6C and R ^6D each independently represents a hydrogen atom, an optionally substituted alkyl group, or Represents an optionally substituted aryl group.

Of the compounds used in the present invention, the compound represented by formula (M) will be described first.
The compound represented by the general formula (M) is preferably a compound that becomes a magenta dye.
D ^{1 to} D ⁵ are each independently a hydrogen atom, a halogen atom (eg, a chlorine atom, a bromine atom, a fluorine atom, etc.), an alkyl group (preferably having 1 to 12 carbon atoms, eg, methyl, ethyl, isopropyl, n- Propyl, t-butyl, etc.), alkoxy groups (preferably having 1 to 12 carbon atoms, such as methoxy, butoxy, octyloxy, dodecyloxy, etc.), aryl groups (preferably having 6 to 10 carbon atoms, such as phenyl, m-nitro, etc. Phenyl, p-nitrophenyl, p-tolyl, naphthyl, etc.), aryloxy groups (preferably having 6 to 10 carbon atoms, such as phenyloxy, m-nitrophenyloxy, p-nitrophenyloxy, p-tolyloxy, naphthyloxy, etc.) ), A cyano group, an acylamino group (preferably having 1 to 12 carbon atoms, such as formylamino, Tilamino, butylcarbonylamino, octylcarbonylamino, etc.), sulfonylamino groups (preferably having 1 to 12 carbon atoms, such as methanesulfonamide, butanesulfonamide, octanesulfonamide, benzenesulfonamide, toluenesulfonamide), ureido group (Preferably having 1 to 12 carbon atoms, such as N-methylureido, N, N-dimethylureido, N-phenylureido, N-methyl-N-phenylureido, N-octylureido, etc.), alkoxycarbonylamino group (preferably 2 to 12 carbon atoms, such as methoxycarbonylamino, ethoxycarbonylamino, isopropoxycarbonylamino, n-octyloxycarbonylamino, etc.)

An alkylthio group (preferably having 1 to 12 carbon atoms, such as methylthio, ethylthio, butylthio, octylthio, isobutylthio t-octylthio, etc.), an arylthio group (preferably having 6 to 10 carbon atoms, such as phenylthio, naphthylthio, etc.), alkoxycarbonyl A group (preferably having 2 to 12 carbon atoms, such as methoxycarbonyl, ethoxycarbonyl, isopropoxycarbonyl, n-octyloxycarbonyl, etc.), a carbamoyl group (preferably having 1 to 12 carbon atoms, such as N-methylcarbamoyl, N, N-dimethylcarbamoyl, N-phenylcarbamoyl, N-butyl-N-phenylcarbamoyl, etc.), sulfamoyl group (preferably having 1 to 12 carbon atoms, such as N-methylsulfamoyl, N-phenylsulfamoyl, N- D Til-N-phenylsulfamoyl, etc.), sulfonyl groups (preferably having 1 to 12 carbon atoms, such as methylsulfonyl, butylsulfonyl, benzenesulfonyl, toluenesulfonyl, etc.), acyl groups (preferably having 1 to 12 carbon atoms, such as , Formyl, acetyl, lauroyl, etc.) or an amino group (preferably having 0 to 12 carbon atoms, such as amino, methylamino, phenylamino, N-methylN-phenylamino, octylamino, etc.), D ⁶ and D ⁷ Each independently represents a hydrogen atom, an alkyl group (preferably having 1 to 12 carbon atoms, such as methyl, ethyl, isopropyl, n-propyl, t-butyl, etc.), an alkoxy group (preferably having 1 to 12 carbon atoms, such as methoxy , Butoxy, octyloxy, dodecyloxy, etc.) or aryl groups (preferred Or C6-C10, such as phenyl, m-nitrophenyl, p-nitrophenyl, p-tolyl, naphthyl, etc.). D ⁶ and D ⁷ may be bonded to each other to form a ring, or D ³ and D ⁶ or / and D ⁴ and D ⁷ may be bonded to each other to form a ring.

X, Y and Z represent ═C (D ⁸ ) — or a nitrogen atom. Here, D ⁸ is a hydrogen atom, an alkyl group (preferably having 1 to 12 carbon atoms, such as methyl, ethyl, isopropyl, n-propyl, t-butyl, etc.), an aryl group (preferably having 6 to 10 carbon atoms, for example, Phenyl, m-nitrophenyl, p-nitrophenyl, p-tolyl, naphthyl, etc.), alkoxy groups (preferably having 1 to 12 carbon atoms, such as methoxy, butoxy, octyloxy, dodecyloxy, etc.), aryloxy groups (preferably Has 6 to 10 carbon atoms such as phenyloxy, m-nitrophenyloxy, p-nitrophenyloxy, p-tolyloxy, naphthyloxy and the like, or an amino group (preferably having 0 to 12 carbon atoms such as amino, methylamino, Phenylamino, N-methyl N-phenylamino, octylamino and the like). When X and Y are = C (D ⁸ )-, or when Y and Z are = C (D ⁸ )-, two D ⁸ are bonded to each other to form a saturated or unsaturated carbocyclic ring. Also good. Each of the above groups may further have a substituent. Examples of the substituent include a halogen atom, alkyl group, alkoxy group, aryl group, aryloxy group, cyano group, acylamino group, sulfonylamino group, ureido group, alkoxycarbonylamino group, alkylthio group, arylthio group, alkoxycarbonyl group, Examples thereof include a carbamoyl group, a sulfamoyl group, a sulfonyl group, an acyl group, a heterocyclic group, a sulfo group, a carboxyl group, a hydroxyl group, and an amino group.
D ¹ is preferably an alkyl group (preferably having a carbon number of 1 to 12, such as methyl, ethyl, isopropyl, n-propyl, t-butyl, etc.), an aryl group (preferably having a carbon number of 6 to 10, such as phenyl, m -Nitrophenyl, p-nitrophenyl, p-tolyl, naphthyl, m-chlorophenyl, p-chlorophenyl, etc.). More preferably, it is an aryl group (preferably having 6 to 10 carbon atoms, such as phenyl, m-nitrophenyl, p-nitrophenyl, p-tolyl, naphthyl, m-chlorophenyl, p-chlorophenyl, etc.).
D ^{2 to} D ⁵ are preferably a hydrogen atom or an alkyl group (preferably having a carbon number of 1 to 12, such as methyl, ethyl, isopropyl, n-propyl, t-butyl, etc.), preferably a hydrogen atom or carbon These are alkyl groups having 1 to 3 and may further have a substituent. Preferred for D ¹¹ is an unsubstituted or substituted alkyl group having 3 to 6 carbon atoms, an alkyl group, an alkoxy group, a nitro group or a cyano group, more preferably an unsubstituted or substituted group having 3 to 6 carbon atoms. , An alkyl group substituted with a cyano group.
D ⁷ is preferably a structure represented by the following general formula (II) or (III).

In the formula, R ⁸ , R ⁹ , R ¹⁰ and R ¹¹ are each independently a hydrogen atom, alkyl group, aryl group, heterocyclic group, halogen atom, alkoxy group, aryloxy group, amino group, acyl group, acyloxy group. Represents an acylamino group, an alkylthio group, an arylthio group, a sulfonylamino group, a sulfonyl group, a sulfinyl group, a carbamoyl group, a sulfamoyl group, an alkoxycarbonyl group or an aryloxycarbonyl group. Preferably, it is a hydrogen atom or an alkyl group (preferably having 1 to 12 carbon atoms, such as methyl, ethyl, isopropyl, n-propyl, t-butyl, etc.), more preferably a hydrogen atom, a methyl group or an ethyl group. . R ⁷ is a hydrogen atom, alkyl group, aryl group, heterocyclic group, halogen atom, alkoxy group, aryloxy group, amino group, acyl group, acyloxy group, acylamino group, alkylthio group, arylthio group, sulfonylamino group, sulfonyl Represents a group, a sulfinyl group, a carbamoyl group, a sulfamoyl group, an alkoxycarbonyl group or an aryloxycarbonyl group. Preferably, it is an aryl group (preferably having 6 to 10 carbon atoms, such as phenyl, m-nitrophenyl, p-nitrophenyl, p-tolyl, p-methoxyphenyl, naphthyl, m-chlorophenyl, p-chlorophenyl, etc.). n represents 1 to 5, preferably 1 to 3. When n is 2 or more, the plurality of R ⁸ , R ⁹ , R ¹⁰ and R ¹¹ may be the same as or different from each other.

  Of the compounds represented by the general formula (M), compounds represented by the following general formula (MB) are preferred.

In the general formula (MB), D ^{19 to} D ²³ are each independently a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an aryl group, an aryloxy group, a cyano group, an acylamino group, a sulfonylamino group, a ureido group, an alkoxy group. carbonylamino group, an alkylthio group, an arylthio group, an alkoxycarbonyl group, a carbamoyl group, a sulfamoyl group, a sulfonyl group, an acyl group or an amino group, D ²⁴ and D ²⁵ represent each independently a hydrogen atom, an alkyl group or an aryl group . D ²⁴ and D ²⁵ may be bonded to each other to form a ring, or D ²¹ and D ²⁴ or / and D ²² and D ²⁵ may be bonded to each other to form a ring. D ²⁶ represents a hydrogen atom, an alkyl group, an aryl group, an alkoxy group, an aryloxy group or an amino group. Each of these groups may further have a substituent.

  Below, the specific example of the pigment | dye represented by general formula (M) is shown. The present invention is not limited thereby.

  These compounds can be easily synthesized by the method described in JP-A-5-286268 or a method analogous thereto.

Next, the compound represented by formula (C) will be described.
The compound represented by the general formula (C) is preferably a cyan dye.
In the general formula (C), D ^{9 to} D ¹⁶ are each independently a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an aryl group, an aryloxy group, a cyano group, an acylamino group, a sulfonylamino group, a ureido group, or an alkoxycarbonyl. It represents an amino group, an alkylthio group, an arylthio group, an alkoxycarbonyl group, a carbamoyl group, a sulfamoyl group, a sulfonyl group, an acyl group or an amino group, and D ¹⁷ and D ¹⁸ each independently represent a hydrogen atom, an alkyl group or an aryl group. D ¹⁷ and D ¹⁸ may be bonded to each other to form a ring, or D ¹⁴ and D ¹⁷ or / and D ¹⁵ and D ¹⁸ may be bonded to each other to form a ring.
D ¹⁴ is preferably an acylamino group, a ureido group and an alkoxycarbonyl group, more preferably an acylamino group and a ureido group, still more preferably an acylamino group, and most preferably a group represented by the following general formula (IV).

Formula (IV)
—NHC (═O) —D ²⁶

In the formula, D ²⁶ is an alkyl group (preferably having a carbon number of 1 to 12, such as methyl, ethyl, isopropyl, n-propyl, t-butyl, etc.), an aryl group (preferably having a carbon number of 6 to 10, such as phenyl, m-nitrophenyl, p-nitrophenyl, p-tolyl, p-methoxyphenyl, naphthyl, m-chlorophenyl, p-chlorophenyl, etc.) or a heterocyclic group (preferably having 0 to 10 carbon atoms, oxygen atom, nitrogen atom or A 5- to 8-membered heterocyclic group containing any of the sulfur atoms as a ring-constituting atom, for example, pyridyl, furyl, tetrahydrofuryl, etc.), preferably a heterocyclic group, more preferably a pyridyl group, a furyl group Or it is a tetrahydrofuryl group.

D ¹⁰ , D ¹¹ , D ^{13 to} D ¹⁶ are preferably a hydrogen atom or an alkyl group (preferably having 1 to 12 carbon atoms, such as methyl, ethyl, isopropyl, n-propyl, t-butyl, etc.). More preferably, they are a hydrogen atom, a methyl group, and an ethyl group. D ¹² is preferably a hydrogen atom, an alkyl group (preferably having 1 to 12 carbon atoms, such as methyl, ethyl, isopropyl, n-propyl, t-butyl, etc.), a halogen atom, a cyano group, a nitro group, a heterocyclic ring. It is a group. More preferably, they are a hydrogen atom and a halogen atom. D ¹⁷ and D ¹⁸ are preferably a hydrogen atom or an alkyl group (preferably having a carbon number of 1 to 12, such as methyl, ethyl, isopropyl, n-propyl, t-butyl, etc.), more preferably a methyl group or ethyl. Group, n-propyl group. These alkyl groups may be further substituted with other substituents. When the alkyl group is substituted, preferred substituents are a heterocyclic group, a halogen atom, an alkoxy group, an aryloxy group, an amino group, an acyl group, an acyloxy group, an acylamino group, an alkylthio group, an arylthio group, a sulfonylamino group, A sulfonyl group, a sulfinyl group, a carbamoyl group, a sulfamoyl group, an alkoxycarbonyl group or an aryloxycarbonyl group, more preferably a carbamoyl group. D ¹⁷ and D ¹⁸ are more preferably a hydrogen atom, a methyl group, or an ethyl group.
Below, the specific example of the pigment | dye represented by general formula (C) is shown. The present invention is not limited thereby.

  These dyes can be easily synthesized by the method described in JP-A-5-305776 or a method analogous thereto.

  In the present invention, the cyan dye contained in the cyan thermal transfer layer is only the compound represented by the general formula (C) and does not contain any other cyan dye. In addition, the compound represented by general formula (C) may be 1 type, or may be multiple types.

Next, the dye used in the yellow ink layer in the thermal transfer sheet of the present invention will be described.
As the yellow dye of the yellow thermal transfer layer (also referred to as yellow ink layer), any dye can be used as long as it can be used in the thermal transfer sheet. It is preferable to use the dye compound represented, and it is more preferable to use the dye compound represented by the general formula (YA) or the general formula (YB).
First, the dye compound represented by the general formula (YA) will be described in detail below.

In the general formula (YA), R ¹¹ represents a monovalent substituent, and R ¹² represents a hydrogen atom or a monovalent substituent. The substituents represented here are not particularly limited, but representative examples include halogen atoms, alkyl groups (in the present specification, saturated aliphatic groups including cycloalkyl groups and bicycloalkyl groups), alkenyl groups (present In the specification, it means a cycloalkenyl group, an unsaturated aliphatic group having a double bond including a bicycloalkenyl group), an alkynyl group, an aryl group, a heterocyclic group, a cyano group, an alkoxy group, an aryloxy group, an acyloxy group , Carbamoyloxy group, alkoxycarbonyloxy group, aryloxycarbonyloxy group, amino group (including alkylamino group, anilino group and heterocyclic amino group), acylamino group, aminocarbonylamino group, alkoxycarbonylamino group, aryloxycarbonyl An amino group, a sulfamoylamino group, Alkyl or arylsulfonylamino group, alkylthio group, sulfamoyl group, alkyl or arylsulfinyl group, alkyl or arylsulfonyl group, acyl group, aryloxycarbonyl group, alkoxycarbonyl group, carbamoyl group, aryl or heterocyclic azo group, imide group And each group may further have a substituent.

Hereinafter, the monovalent substituents represented by R ¹¹ and R ¹² will be described in more detail.
In addition, the monovalent substituent here applies not only to R ¹¹ and R ¹² but also to all substituents such as the substituent used in the present invention, the monovalent substituent, and the substituent which may have a substituent. Is.
Examples of the halogen atom represented by R ¹¹ and R ¹² include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Of these, a chlorine atom and a bromine atom are preferable, and a chlorine atom is particularly preferable.
The alkyl group represented by R ¹¹ and R ¹² includes a cycloalkyl group and a bicycloalkyl group. The alkyl group includes a straight-chain, branched substituted or unsubstituted alkyl group. The linear, branched substituted or unsubstituted alkyl group is preferably an alkyl group having 1 to 30 carbon atoms. Examples include methyl, ethyl, n-propyl, isopropyl, tert-butyl, n-octyl, eicosyl, 2-chloroethyl, 2-cyanoethyl, and 2-ethylhexyl. . The cycloalkyl group includes a substituted or unsubstituted cycloalkyl group. The substituted or unsubstituted cycloalkyl group is preferably a cycloalkyl group having 3 to 30 carbon atoms. Examples include a cyclohexyl group, a cyclopentyl group, and a 4-n-dodecylcyclohexyl group. Examples of the bicycloalkyl group include a substituted or unsubstituted bicycloalkyl group having 5 to 30 carbon atoms, that is, a monovalent group obtained by removing one hydrogen atom from a bicycloalkane having 5 to 30 carbon atoms. Examples include a bicyclo [1,2,2] heptan-2-yl group and a bicyclo [2,2,2] octan-3-yl group. Further, it includes a tricyclo structure having many ring structures. In addition, “alkyl” (for example, “alkyl” of an alkylthio group) in the substituents described below also represents “alkyl” of such a concept.

The alkenyl group represented by R ¹¹ and R ¹² cycloalkenyl groups include bicycloalkenyl group. The alkenyl group represents a linear, branched, or cyclic substituted or unsubstituted alkenyl group. As the alkenyl group, a substituted or unsubstituted alkenyl group having 2 to 30 carbon atoms is preferable. Examples include vinyl groups, allyl groups, prenyl groups, geranyl groups, and oleyl groups. The cycloalkenyl group is preferably a substituted or unsubstituted cycloalkenyl group having 3 to 30 carbon atoms, that is, a monovalent group obtained by removing one hydrogen atom of a cycloalkene having 3 to 30 carbon atoms. Examples include a 2-cyclopenten-1-yl group and a 2-cyclohexen-1-yl group. The bicycloalkenyl group includes a substituted or unsubstituted bicycloalkenyl group. The bicycloalkenyl group is preferably a substituted or unsubstituted bicycloalkenyl group having 5 to 30 carbon atoms, that is, a monovalent group in which one hydrogen atom of a bicycloalkene having one double bond is removed. Examples include bicyclo [2,2,1] hept-2-en-1-yl group and bicyclo [2,2,2] oct-2-en-4-yl group.
The alkynyl group represented by R ¹¹ and R ¹² is preferably a substituted or unsubstituted alkynyl group having 2 to 30 carbon atoms, and examples thereof include an ethynyl group and a propargyl group.
The aryl group represented by R ¹¹ and R ¹² is preferably a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, such as a phenyl group, p-tolyl group, naphthyl group, m-chlorophenyl group, o-hexa. A decanoylaminophenyl group is mentioned.

The heterocyclic group represented by R ¹¹ and R ¹² is a monovalent group obtained by removing one hydrogen atom from a substituted or unsubstituted aromatic or non-aromatic heterocyclic compound, and these are further condensed. It may be. These heterocyclic groups are preferably 5- or 6-membered heterocyclic groups, and the hetero atoms of the ring structure are preferably oxygen atoms, sulfur atoms and nitrogen atoms. More preferably, it is a 5- or 6-membered aromatic heterocyclic group having 3 to 30 carbon atoms. Examples of the ring constituting the heterocyclic group without limiting the substitution position include pyridine ring, pyrazine ring, pyridazine ring, pyrimidine ring, triazine ring, quinoline ring, isoquinoline ring, quinazoline ring, cinnoline ring, phthalazine ring, quinoxaline ring , Pyrrole ring, indole ring, furan ring, benzofuran ring, thiophene ring, benzothiophene ring, pyrazole ring, imidazole ring, benzimidazole ring, triazole ring, oxazole ring, benzoxazole ring, thiazole ring, benzothiazole ring, isothiazole ring Benzisothiazole ring, thiadiazole ring, isoxazole ring, benzisoxazole ring, pyrrolidine ring, piperidine ring, piperazine ring, imidazolidine ring and thiazoline ring.

The alkoxy group represented by R ¹¹ and R ¹² includes a substituted or unsubstituted alkoxy group. As the substituted or unsubstituted alkoxy group, an alkoxy group having 1 to 30 carbon atoms is preferable. Examples of the alkoxy group include methoxy group, ethoxy group, isopropoxy group, n-octyloxy group, methoxyethoxy group, hydroxyethoxy group, and 3-carboxypropoxy group.
The aryloxy group represented by R ¹¹ and R ¹² is preferably a substituted or unsubstituted aryloxy group having 6 to 30 carbon atoms. Examples of the aryloxy group include phenoxy group, 2-methylphenoxy group, 4-tert-butylphenoxy group, 3-nitrophenoxy group, 2-tetradecanoylaminophenoxy group and the like.

The acyloxy group represented by R ¹¹ and R ¹² is preferably a formyloxy group, a substituted or unsubstituted alkylcarbonyloxy group having 2 to 30 carbon atoms, or a substituted or unsubstituted arylcarbonyloxy group having 6 to 30 carbon atoms. . Examples of the acyloxy group include formyloxy group, acetyloxy group, pivaloyloxy group, stearoyloxy group, benzoyloxy group, p-methoxyphenylcarbonyloxy group and the like.
The carbamoyloxy group represented by R ¹¹ and R ¹² is preferably a substituted or unsubstituted carbamoyloxy group having 1 to 30 carbon atoms. Examples of carbamoyloxy groups include N, N-dimethylcarbamoyloxy group, N, N-diethylcarbamoyloxy group, morpholinocarbonyloxy group, N, N-di-n-octylaminocarbonyloxy group, Nn-octyl A carbamoyloxy group can be exemplified.

The alkoxycarbonyloxy group represented by R ¹¹ and R ¹² is preferably a substituted or unsubstituted alkoxycarbonyloxy group having 2 to 30 carbon atoms. Examples of the alkoxycarbonyloxy group include a methoxycarbonyloxy group, an ethoxycarbonyloxy group, a tert-butoxycarbonyloxy group, and an n-octylcarbonyloxy group.
The aryloxycarbonyloxy group represented by R ¹¹ and R ¹² is preferably a substituted or unsubstituted aryloxycarbonyloxy group having 7 to 30 carbon atoms. Examples of the aryloxycarbonyloxy group include a phenoxycarbonyloxy group, a p-methoxyphenoxycarbonyloxy group, and a pn-hexadecyloxyphenoxycarbonyloxy group.

The amino group represented by R ¹¹ and R ¹² includes an alkylamino group, an arylamino group, and a heterocyclic amino group. The amino group is preferably a substituted or unsubstituted alkylamino group having 1 to 30 carbon atoms and a substituted or unsubstituted arylamino group having 6 to 30 carbon atoms. Examples of amino groups include, for example, amino group, methylamino group, dimethylamino group, anilino group, N-methyl-anilino group, diphenylamino group, hydroxyethylamino group, carboxyethylamino group, sulfoethylamino group, 3,5-Dicarboxyanilino group, 4-quinolylamino group and the like can be mentioned.
The acylamino group represented by R ¹¹ and R ¹² is preferably a formylamino group, a substituted or unsubstituted alkylcarbonylamino group having 1 to 30 carbon atoms, or a substituted or unsubstituted arylcarbonylamino group having 6 to 30 carbon atoms. . Examples of the acylamino group include formylamino group, acetylamino group, pivaloylamino group, lauroylamino group, benzoylamino group, 3,4,5-tri-n-octyloxyphenylcarbonylamino group, and the like.
The aminocarbonylamino group represented by R ¹¹ and R ¹² is preferably a substituted or unsubstituted aminocarbonylamino group having 1 to 30 carbon atoms. Examples of the aminocarbonylamino group include carbamoylamino group, N, N-dimethylaminocarbonylamino group, N, N-diethylaminocarbonylamino group, morpholinocarbonylamino group and the like. The term “amino” in this group has the same meaning as “amino” in the aforementioned amino group.

The alkoxycarbonylamino group represented by R ¹¹ and R ¹² is preferably a substituted or unsubstituted alkoxycarbonylamino group having 2 to 30 carbon atoms. Examples of the alkoxycarbonylamino group include a methoxycarbonylamino group, an ethoxycarbonylamino group, a tert-butoxycarbonylamino group, an n-octadecyloxycarbonylamino group, and an N-methyl-methoxycarbonylamino group.
The aryloxycarbonylamino group represented by R ¹¹ and R ¹² is preferably a substituted or unsubstituted aryloxycarbonylamino group having 7 to 30 carbon atoms. Examples of the aryloxycarbonylamino group include phenoxycarbonylamino group, p-chlorophenoxycarbonylamino group, mn-octyloxyphenoxycarbonylamino group, and the like.

The sulfamoylamino group represented by R ¹¹ and R ¹² is preferably a substituted or unsubstituted sulfamoylamino group having 0 to 30 carbon atoms. Examples of the sulfamoylamino group include a sulfamoylamino group, an N, N-dimethylaminosulfonylamino group, and an Nn-octylaminosulfonylamino group.
The alkyl or arylsulfonylamino group represented by R ¹¹ and R ¹² is preferably a substituted or unsubstituted alkylsulfonylamino group having 1 to 30 carbon atoms, or a substituted or unsubstituted arylsulfonylamino group having 6 to 30 carbon atoms. . Examples of the alkylsulfonylamino group and arylsulfonylamino group include methylsulfonylamino group, butylsulfonylamino group, phenylsulfonylamino group, 2,3,5-trichlorophenylsulfonylamino group, p-methylphenylsulfonylamino group and the like. Can be mentioned.

The alkylthio group represented by R ¹¹ and R ¹² is preferably a substituted or unsubstituted alkylthio group having 1 to 30 carbon atoms. Examples of the alkylthio group include a methylthio group, an ethylthio group, and an n-hexadecylthio group.
The sulfamoyl group represented by R ¹¹ and R ¹² is preferably a substituted or unsubstituted sulfamoyl group having 0 to 30 carbon atoms. Examples of the sulfamoyl group include N-ethylsulfamoyl group, N- (3-dodecyloxypropyl) sulfamoyl group, N, N-dimethylsulfamoyl group, N-acetylsulfamoyl group, N-benzoylsulfa group. A moyl group, an N- (N′-phenylcarbamoyl) sulfamoyl group, and the like can be given.

The alkyl or arylsulfinyl group represented by R ¹¹ and R ¹² is preferably a substituted or unsubstituted alkylsulfinyl group having 1 to 30 carbon atoms, or a substituted or unsubstituted arylsulfinyl group having 6 to 30 carbon atoms. Examples of the alkyl or arylsulfinyl group include a methylsulfinyl group, an ethylsulfinyl group, a phenylsulfinyl group, and a p-methylphenylsulfinyl group.
The alkyl or arylsulfonyl group represented by R ¹¹ and R ¹² is preferably a substituted or unsubstituted alkylsulfonyl group having 1 to 30 carbon atoms, or a substituted or unsubstituted arylsulfonyl group having 6 to 30 carbon atoms. Examples of the alkyl or arylsulfonyl group include a methylsulfonyl group, an ethylsulfonyl group, a phenylsulfonyl group, and a p-toluenesulfonyl group.

The acyl group represented by R ¹¹ and R ¹² is a formyl group, a substituted or unsubstituted alkylcarbonyl group having 2 to 30 carbon atoms, a substituted or unsubstituted arylcarbonyl group having 7 to 30 carbon atoms, or 4 to 4 carbon atoms. A heterocyclic carbonyl group bonded to a carbonyl group with 30 substituted or unsubstituted carbon atoms is preferred. Examples of the acyl group include, for example, acetyl group, pivaloyl group, 2-chloroacetyl group, stearoyl group, benzoyl group, pn-octyloxyphenylcarbonyl group, 2-pyridylcarbonyl group, 2-furylcarbonyl group and the like. Can be mentioned.

The alkoxycarbonyl group represented by R ¹¹ and R ¹² is preferably a substituted or unsubstituted alkoxycarbonyl group having 2 to 30 carbon atoms. Examples of the alkoxycarbonyl group include methoxycarbonyl group, ethoxycarbonyl group, tert-butoxycarbonyl group, n-octadecyloxycarbonyl group and the like.
The aryloxycarbonyl group represented by R ¹¹ and R ¹² is preferably a substituted or unsubstituted aryloxycarbonyl group having 7 to 30 carbon atoms. Examples of the aryloxycarbonyl group include phenoxycarbonyl group, o-chlorophenoxycarbonyl group, m-nitrophenoxycarbonyl group, p-tert-butylphenoxycarbonyl group and the like.

The carbamoyl group represented by R ¹¹ and R ¹² is preferably a substituted or unsubstituted carbamoyl group having 1 to 30 carbon atoms. Examples of the carbamoyl group include a carbamoyl group, an N-methylcarbamoyl group, an N, N-dimethylcarbamoyl group, an N, N-di-n-octylcarbamoyl group, and an N- (methylsulfonyl) carbamoyl group. .
As the aryl or heterocyclic azo group represented by R ¹¹ and R ¹² , for example, phenylazo group, 4-methoxyphenylazo group, 4-pivaloylaminophenylazo group, 2-hydroxy-4-propanoylphenylazo group And so on.
Examples of the imide group represented by R ¹¹ and R ¹² include an N-succinimide group and an N-phthalimide group.

In general formula (YA), X represents an atomic group necessary for forming a ring. Not specifically defined, the here necessary to form a ring atom group, as a representative ^{example, -C (R 13) = N} -, - N = C (R 13) -, - C (= O) An atomic group represented by —C (R ¹³ ) ═C (R ¹⁴ ) — and —C (═O) —N (R ¹³ ) —C (═O) — can be given. Here, R ¹³ and R ¹⁴ each independently represents a hydrogen atom or a substituent. Examples of substituents, examples given as the substituent of R ¹¹ and R ¹² can be mentioned.

In the general formula (YA), Ar ¹ is a group selected from the group (1) of the heterocyclic group. In each group of the heterocyclic group (1), R ⁶¹ , R ⁶² , R ⁶³ , R ⁶⁴ and R ⁶⁵ each independently represent a hydrogen atom or a substituent. Examples of substituents, examples given as the substituent of R ¹¹ and R ¹² can be mentioned.

R ¹¹ is preferably a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, or a substituted or unsubstituted acyl group, more preferably An unsubstituted alkyl group having 1 to 4 carbon atoms.
R ¹² is preferably a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted amino group, a substituted or unsubstituted alkoxy group , A hydroxy group, more preferably a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group, still more preferably a substituted or unsubstituted alkyl group, and particularly preferably a branched alkyl group.
X is preferably —C (R ¹⁴ ) ═N— or —N═C (R ¹⁴ ) —.

As for the preferred combination of substituents of the dye represented by the general formula (YA), a compound in which at least one of various substituents is the above preferred group is preferable, and more various substituents are the above preferred groups. Compounds are more preferred, and compounds in which all substituents are the preferred groups are most preferred. Specific examples of preferred combinations include R ¹¹ is an unsubstituted alkyl group having 1 to 6 carbon atoms, R ¹² is a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted aryl group, X is —C (R ¹⁴ ) ═N— or —N═C (R ¹⁴ ) —, and Ar ¹ is a group selected from the group (1) of the heterocyclic group.

  The molecular weight of the compound represented by the general formula (YA) is preferably 500 or less, and more preferably 450 or less, from the viewpoint of thermal diffusibility.

Although the specific example of the pigment | dye represented with general formula (YA) of this invention below is shown, this invention is not limited to these. In the following specific examples, Ph represents a phenyl group (—C ₆ H ₅ ).

These compounds can be easily synthesized by diazo coupling a diazonium salt obtained from a heterocyclic amino group defined by Ar ¹ and a condensed heterocyclic compound.
The preferred range for the maximum absorption wavelength of the azo dye of the present invention is preferably 400 to 480 nm, more preferably 420 to 460 nm.

Next, the compound represented by the general formula (YB) will be described.
In the general formula (YB), R ¹ , R ³ and R ⁴ represent a hydrogen atom or a monovalent substituent. The substituents represented here are not particularly limited, but representative examples include halogen atoms, alkyl groups (in the present specification, saturated aliphatic groups including cycloalkyl groups and bicycloalkyl groups), alkenyl groups (present In the specification, it means a cycloalkenyl group, an unsaturated aliphatic group having a double bond including a bicycloalkenyl group), an alkynyl group, an aryl group, a heterocyclic group, a cyano group, an alkoxy group, an aryloxy group, an acyloxy group , Carbamoyloxy group, alkoxycarbonyloxy group, aryloxycarbonyloxy group, amino group (including alkylamino group, anilino group and heterocyclic amino group), acylamino group, aminocarbonylamino group, alkoxycarbonylamino group, aryloxycarbonyl An amino group, a sulfamoylamino group, Alkyl or arylsulfonylamino group, alkylthio group, sulfamoyl group, alkyl or arylsulfinyl group, alkyl or arylsulfonyl group, acyl group, aryloxycarbonyl group, alkoxycarbonyl group, carbamoyl group, aryl or heterocyclic azo group, imide group And each group may further have a substituent.
In the general formula (YB), R ² and R ⁶ represent a hydrogen atom or a monovalent substituent. There are no particular restrictions on the substituents represented here, but typical examples include alkyl groups, alkenyl groups, alkynyl groups, aryl groups, heterocyclic groups, acyl groups, aryloxycarbonyl groups, alkoxycarbonyl groups, and carbamoyl groups. Each group may further have a substituent.
In the general formula (YB), R ⁵ represents a monovalent substituent. The substituents represented here are not particularly limited, but as typical examples, alkyl groups, alkenyl groups, alkynyl groups, aryl groups, heterocyclic groups, alkoxy groups, aryloxy groups, acyloxy groups, amino groups (alkylamino groups, Anilino group and heterocyclic amino group), acylamino group, aminocarbonylamino group, alkoxycarbonylamino group, aryloxycarbonylamino group, sulfamoylamino group, alkyl or arylsulfonylamino group, and alkylthio group. Each group may further have a substituent.

Hereinafter, the monovalent substituent will be described in more detail.
In addition, the monovalent substituent here is applied to all the substituents used in the present invention, such as a substituent, a monovalent substituent, and a substituent which may have a substituent.

  Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Of these, a chlorine atom and a bromine atom are preferable, and a chlorine atom is particularly preferable.

  The alkyl group includes a cycloalkyl group and a bicycloalkyl group. The alkyl group includes a straight-chain, branched substituted or unsubstituted alkyl group. The linear, branched substituted or unsubstituted alkyl group is preferably an alkyl group having 1 to 30 carbon atoms. Examples include methyl, ethyl, n-propyl, isopropyl, tert-butyl, n-octyl, eicosyl, 2-chloroethyl, 2-cyanoethyl, and 2-ethylhexyl. . The cycloalkyl group includes a substituted or unsubstituted cycloalkyl group. The substituted or unsubstituted cycloalkyl group is preferably a cycloalkyl group having 3 to 30 carbon atoms. Examples include a cyclohexyl group, a cyclopentyl group, and a 4-n-dodecylcyclohexyl group. Examples of the bicycloalkyl group include a substituted or unsubstituted bicycloalkyl group having 5 to 30 carbon atoms, that is, a monovalent group obtained by removing one hydrogen atom from a bicycloalkane having 5 to 30 carbon atoms. Examples include a bicyclo [1,2,2] heptan-2-yl group and a bicyclo [2,2,2] octan-3-yl group. Further, it includes a tricyclo structure having many ring structures. “Alkyl” in the substituents described below (for example, “alkyl” of an alkylthio group) also represents “alkyl” of such a concept.

  The alkenyl group includes a cycloalkenyl group and a bicycloalkenyl group. The alkenyl group represents a linear, branched, or cyclic substituted or unsubstituted alkenyl group. As the alkenyl group, a substituted or unsubstituted alkenyl group having 2 to 30 carbon atoms is preferable. Examples include vinyl group, allyl group, prenyl group, geranyl group, and oleyl group. The cycloalkenyl group is preferably a substituted or unsubstituted cycloalkenyl group having 3 to 30 carbon atoms, that is, a monovalent group obtained by removing one hydrogen atom of a cycloalkene having 3 to 30 carbon atoms. Examples include a 2-cyclopenten-1-yl group and a 2-cyclohexen-1-yl group. The bicycloalkenyl group includes a substituted or unsubstituted bicycloalkenyl group. The bicycloalkenyl group is preferably a substituted or unsubstituted bicycloalkenyl group having 5 to 30 carbon atoms, that is, a monovalent group in which one hydrogen atom of a bicycloalkene having one double bond is removed. Examples include bicyclo [2,2,1] hept-2-en-1-yl group and bicyclo [2,2,2] oct-2-en-4-yl group.

  The alkynyl group is preferably a substituted or unsubstituted alkynyl group having 2 to 30 carbon atoms, and examples thereof include an ethynyl group and a propargyl group.

  The aryl group is preferably a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, and examples thereof include a phenyl group, a p-tolyl group, a naphthyl group, an m-chlorophenyl group, and an o-hexadecanoylaminophenyl group.

  The heterocyclic group is a monovalent group obtained by removing one hydrogen atom from a substituted or unsubstituted aromatic or non-aromatic heterocyclic compound, and they may be further condensed. These heterocyclic groups are preferably 5- or 6-membered heterocyclic groups, and the hetero atoms of the ring structure are preferably oxygen atoms, sulfur atoms and nitrogen atoms. More preferably, it is a 5- or 6-membered aromatic heterocyclic group having 3 to 30 carbon atoms. Examples of the ring constituting the heterocyclic group without limiting the substitution position include pyridine ring, pyrazine ring, pyridazine ring, pyrimidine ring, triazine ring, quinoline ring, isoquinoline ring, quinazoline ring, cinnoline ring, phthalazine ring, quinoxaline ring, Pyrrole ring, indole ring, furan ring, benzofuran ring, thiophene ring, benzothiophene ring, pyrazole ring, imidazole ring, benzimidazole ring, triazole ring, oxazole ring, benzoxazole ring, thiazole ring, benzothiazole ring, isothiazole ring, Examples thereof include a benzisothiazole ring, a thiadiazole ring, an isoxazole ring, a benzisoxazole ring, a pyrrolidine ring, a piperidine ring, a piperazine ring, an imidazolidine ring, and a thiazoline ring.

  The alkoxy group includes a substituted or unsubstituted alkoxy group. As the substituted or unsubstituted alkoxy group, an alkoxy group having 1 to 30 carbon atoms is preferable. Examples of the alkoxy group include methoxy group, ethoxy group, isopropoxy group, n-octyloxy group, methoxyethoxy group, hydroxyethoxy group, and 3-carboxypropoxy group.

  The aryloxy group is preferably a substituted or unsubstituted aryloxy group having 6 to 30 carbon atoms. Examples of the aryloxy group include phenoxy group, 2-methylphenoxy group, 4-tert-butylphenoxy group, 3-nitrophenoxy group, 2-tetradecanoylaminophenoxy group and the like.

  The acyloxy group is preferably a formyloxy group, a substituted or unsubstituted alkylcarbonyloxy group having 2 to 30 carbon atoms, or a substituted or unsubstituted arylcarbonyloxy group having 6 to 30 carbon atoms. Examples of the acyloxy group include formyloxy group, acetyloxy group, pivaloyloxy group, stearoyloxy group, benzoyloxy group, p-methoxyphenylcarbonyloxy group and the like.

  The carbamoyloxy group is preferably a substituted or unsubstituted carbamoyloxy group having 1 to 30 carbon atoms. Examples of carbamoyloxy groups include N, N-dimethylcarbamoyloxy group, N, N-diethylcarbamoyloxy group, morpholinocarbonyloxy group, N, N-di-n-octylaminocarbonyloxy group, Nn-octyl A carbamoyloxy group can be exemplified.

  The alkoxycarbonyloxy group is preferably a substituted or unsubstituted alkoxycarbonyloxy group having 2 to 30 carbon atoms. Examples of the alkoxycarbonyloxy group include a methoxycarbonyloxy group, an ethoxycarbonyloxy group, a tert-butoxycarbonyloxy group, and an n-octylcarbonyloxy group.

  The aryloxycarbonyloxy group is preferably a substituted or unsubstituted aryloxycarbonyloxy group having 7 to 30 carbon atoms. Examples of the aryloxycarbonyloxy group include a phenoxycarbonyloxy group, a p-methoxyphenoxycarbonyloxy group, and a pn-hexadecyloxyphenoxycarbonyloxy group.

  The amino group includes an alkylamino group, an arylamino group, and a heterocyclic amino group. The amino group is preferably a substituted or unsubstituted alkylamino group having 1 to 30 carbon atoms and a substituted or unsubstituted arylamino group having 6 to 30 carbon atoms. Examples of amino groups include, for example, amino group, methylamino group, dimethylamino group, anilino group, N-methyl-anilino group, diphenylamino group, hydroxyethylamino group, carboxyethylamino group, sulfoethylamino group, 3,5-Dicarboxyanilino group, 4-quinolylamino group and the like can be mentioned.

  The acylamino group is preferably a formylamino group, a substituted or unsubstituted alkylcarbonylamino group having 1 to 30 carbon atoms, or a substituted or unsubstituted arylcarbonylamino group having 6 to 30 carbon atoms. Examples of the acylamino group include formylamino group, acetylamino group, pivaloylamino group, lauroylamino group, benzoylamino group, 3,4,5-tri-n-octyloxyphenylcarbonylamino group, and the like.

  The aminocarbonylamino group is preferably a substituted or unsubstituted aminocarbonylamino group having 1 to 30 carbon atoms. Examples of the aminocarbonylamino group include carbamoylamino group, N, N-dimethylaminocarbonylamino group, N, N-diethylaminocarbonylamino group, morpholinocarbonylamino group and the like. The term “amino” in this group has the same meaning as “amino” in the aforementioned amino group.

  The alkoxycarbonylamino group is preferably a substituted or unsubstituted alkoxycarbonylamino group having 2 to 30 carbon atoms. Examples of the alkoxycarbonylamino group include methoxycarbonylamino group, ethoxycarbonylamino group, tert-butoxycarbonylamino group, n-octadecyloxycarbonylamino group, N-methyl-methoxycarbonylamino group and the like.

  The aryloxycarbonylamino group is preferably a substituted or unsubstituted aryloxycarbonylamino group having 7 to 30 carbon atoms. Examples of the aryloxycarbonylamino group include phenoxycarbonylamino group, p-chlorophenoxycarbonylamino group, mn-octyloxyphenoxycarbonylamino group, and the like.

  The sulfamoylamino group is preferably a substituted or unsubstituted sulfamoylamino group having 0 to 30 carbon atoms. Examples of the sulfamoylamino group include a sulfamoylamino group, an N, N-dimethylaminosulfonylamino group, and an Nn-octylaminosulfonylamino group.

  The alkyl or arylsulfonylamino group is preferably a substituted or unsubstituted alkylsulfonylamino group having 1 to 30 carbon atoms or a substituted or unsubstituted arylsulfonylamino group having 6 to 30 carbon atoms. Examples of the alkylsulfonylamino group and arylsulfonylamino group include methylsulfonylamino group, butylsulfonylamino group, phenylsulfonylamino group, 2,3,5-trichlorophenylsulfonylamino group, p-methylphenylsulfonylamino group and the like. Can be mentioned.

  The alkylthio group is preferably a substituted or unsubstituted alkylthio group having 1 to 30 carbon atoms. Examples of the alkylthio group include a methylthio group, an ethylthio group, and an n-hexadecylthio group.

  The sulfamoyl group is preferably a substituted or unsubstituted sulfamoyl group having 0 to 30 carbon atoms. Examples of the sulfamoyl group include N-ethylsulfamoyl group, N- (3-dodecyloxypropyl) sulfamoyl group, N, N-dimethylsulfamoyl group, N-acetylsulfamoyl group, N-benzoylsulfa group. A moyl group, an N- (N′-phenylcarbamoyl) sulfamoyl) group, and the like.

  The alkyl or arylsulfinyl group is preferably a substituted or unsubstituted alkylsulfinyl group having 1 to 30 carbon atoms, or a substituted or unsubstituted arylsulfinyl group having 6 to 30 carbon atoms. Examples of the alkyl or arylsulfinyl group include a methylsulfinyl group, an ethylsulfinyl group, a phenylsulfinyl group, and a p-methylphenylsulfinyl group.

  The alkyl or arylsulfonyl group is preferably a substituted or unsubstituted alkylsulfonyl group having 1 to 30 carbon atoms, or a substituted or unsubstituted arylsulfonyl group having 6 to 30 carbon atoms. Examples of the alkyl or arylsulfonyl group include methylsulfonyl, ethylsulfonyl, phenylsulfonyl, p-toluenesulfonyl group and the like.

  The acyl group includes a formyl group, a substituted or unsubstituted alkylcarbonyl group having 2 to 30 carbon atoms, a substituted or unsubstituted arylcarbonyl group having 7 to 30 carbon atoms, and a substituted or unsubstituted carbon atom having 4 to 30 carbon atoms. And a heterocyclic carbonyl group bonded to a carbonyl group is preferred. Examples of the acyl group include acetyl, pivaloyl, 2-chloroacetyl, stearoyl, benzoyl, pn-octyloxyphenylcarbonyl, 2-pyridylcarbonyl, 2-furylcarbonyl group and the like.

  The aryloxycarbonyl group is preferably a substituted or unsubstituted aryloxycarbonyl group having 7 to 30 carbon atoms. Examples of the aryloxycarbonyl group include phenoxycarbonyl, o-chlorophenoxycarbonyl, m-nitrophenoxycarbonyl, p-tert-butylphenoxycarbonyl group and the like.

  The alkoxycarbonyl group is preferably a substituted or unsubstituted alkoxycarbonyl group having 2 to 30 carbon atoms. Examples of the alkoxycarbonyl group include methoxycarbonyl, ethoxycarbonyl, tert-butoxycarbonyl, n-octadecyloxycarbonyl group and the like.

  The carbamoyl group is preferably a substituted or unsubstituted carbamoyl group having 1 to 30 carbon atoms. Examples of the carbamoyl group include carbamoyl, N-methylcarbamoyl, N, N-dimethylcarbamoyl, N, N-di-n-octylcarbamoyl, N- (methylsulfonyl) carbamoyl group and the like.

  Examples of the aryl or heterocyclic azo group include phenylazo, 4-methoxyphenylazo, 4-pivaloylaminophenylazo, 2-hydroxy-4-propanoylphenylazo group, and the like.

  Examples of the imide group include an N-succinimide group and an N-phthalimide group.

R ¹ is preferably a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms, a substituted or unsubstituted aryl group, a cyano group, a substituted or unsubstituted alkoxycarbonyl group having 1 to 4 carbon atoms, substituted or unsubstituted And more preferably a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms, a substituted or unsubstituted aryl group, a substituted or unsubstituted alkoxycarbonyl group having 1 to 4 carbon atoms, and a carbamoyl group. And most preferably an unsubstituted alkyl group having 1 to 4 carbon atoms.

R ² is preferably a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, or a substituted or unsubstituted acyl group, more preferably A substituted or unsubstituted alkyl group having 1 to 4 carbon atoms, a substituted or unsubstituted aryl group, and most preferably an unsubstituted alkyl group having 1 to 4 carbon atoms.

R ³ and R ⁴ are each independently preferably an electron-withdrawing group having a Hammett substituent constant σp value of 0.2 to 1.0. R ³ is more preferably an electron-withdrawing group having a σp value of 0.30 or more, more preferably an electron-withdrawing group of 0.45 or more, and an electron-withdrawing group of 0.60 or more. Is particularly preferred. The upper limit of σp is preferably 1.0 or less. Examples of electron withdrawing groups having a σp value of 0.60 or more include a nitro group, a cyano group, a methanesulfonyl group, a trifluoromethanesulfonyl group, a trifluoroacetyl group, a dimethylaminosulfonyl group, a sulfamoyl group, and the like. Examples of the electron withdrawing group having a value of 0.45 or more include an alkoxycarbonyl group, an acyl group, and a carboxy group. Examples of the electron withdrawing group having a σp value of 0.30 or more include a sulfo group and a carbamoyl group. Groups.
A cyano group, a carboxyl group, an alkoxycarbonyl group, and a carbamoyl group are more preferable, a cyano group, an alkoxycarbonyl group, and a carbamoyl group are more preferable, and a cyano group is most preferable.

Here, Hammett's substituent constant σp value will be described briefly.
Hammett's rule is described in 1935 by L.L. in order to quantitatively discuss the effect of substituents on the reaction or equilibrium of benzene derivatives. P. A rule of thumb proposed by Hammett, which is widely accepted today. Substituent constants determined by Hammett's rule include σp value and σm value, and these values can be found in many general books. A. Dean [Lange's Handbook of Chemistry] 12th edition, 1979 (McGraw-Hill) and “Areas of Chemistry”, Special Issue 122, pages 96-103, 1979 (Nankodo). In the present specification, each substituent is limited or explained by Hammett's substituent constant σp, but this is limited to only a substituent having a known value that can be found in the above-mentioned book. It does not mean that it also includes substituents that would be included within that range when measured based on Hammett's rule, even if the value is unknown. In addition, the general formula of the present invention includes those that are not benzene derivatives, but the σp value is used as a scale indicating the electronic effect of the substituent regardless of the substitution position. In this specification, the σp value is used in this sense.

R ⁵ is preferably a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms, a dialkylamino group having 2 to 10 carbon atoms, a substituted or unsubstituted alkoxy group, or a substituted or unsubstituted aryl group, more preferably Is a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms, a dialkylamino group having 2 to 10 carbon atoms, or a substituted or unsubstituted alkoxy group, and most preferably a dialkylamino group having 2 to 10 carbon atoms. .

As for the preferred combination of substituents of the dye represented by the general formula (YB) of the present invention, a compound in which at least one of various substituents is the above preferred group is preferred, and more various substituents are preferred. More preferred are compounds that are groups, and most preferred are compounds in which all substituents are the preferred groups.
A preferred combination is that R ¹ is a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms, R ² is a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms or a substituted or unsubstituted aryl group, and R ³ is cyano. Group or alkoxycarbonyl group, R ⁴ is cyano group or alkoxycarbonyl group, R ⁵ is substituted or unsubstituted alkyl group having 1 to 4 carbon atoms, dialkylamino group having 2 to 10 carbon atoms, substituted or unsubstituted alkoxy group , A substituted or unsubstituted aryl group.
A more preferred combination is that R ¹ is a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms, R ² is a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms, or a substituted or unsubstituted aryl group, and R ³ is A cyano group, R ⁴ is a cyano group, and R ⁵ is a dialkylamino group having 2 to 10 carbon atoms.
A most preferred combination is that R ¹ is a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms, R ² is a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms, or a substituted or unsubstituted aryl group, and R ³ is A cyano group, R ⁴ is a cyano group, and R ⁵ is a dialkylamino group having 2 to 4 carbon atoms.

  The molecular weight of the compound represented by the general formula (YB) is preferably 500 or less, and more preferably 450 or less, from the viewpoint of thermal diffusivity.

Specific examples of the azo dye represented by the general formula (YB) of the present invention are shown below, but the azo dye of the general formula (YB) that can be used in the present invention is not limited by the following specific examples. Absent. In the following specific examples, Ph represents a phenyl group (—C ₆ H ₅ ).

Next, the compound represented by general formula (YC) is demonstrated.
R ^A , R ^B , R ^C , R ^D and R ^E in the general formula (YC) are each independently a hydrogen atom, an alkyl group of a halogen atom C _{1 to} C ₈ , a cycloalkyl group, an alkoxy group or an alkoxyalkoxy group. , An alkoxyalkenyl group, a thioalkoxy group, an alkylsulfonyl group, an amino group, a substituted or unsubstituted phenoxy group, or a substituted or unsubstituted thiophenoxy group. R ^F and R ^G are each independently a hydrogen atom, an alkyl group, an alkoxyalkyl group, a cycloalkyl group, an allyl group, an aryl group that may have a substituent, an aralkyl group, a furfuryl group, a tetrahydrofurfuryl group, or Represents a hydroxyalkyl group.

  Specific examples of the yellow dye represented by the general formula (YC) of the present invention are shown below, but the yellow dye represented by the general formula (YC) that can be used in the present invention is limited by the following specific examples. It is not something.

Next, the compound represented by general formula (YD) is demonstrated.
R ^1A in the general formula (YD) represents an allyl group or an alkyl group, R ^2A represents a substituted or unsubstituted alkyl group or an aryl group, and A represents —CH ₂ —, —CH ₂ CH ₂ —, — CH ₂ CH ₂ O—, —CH ₂ CH ₂ OCH ₂ —, —CH ₂ CH ₂ OCH ₂ CH ₂ — are represented, and R ^3A represents an alkyl group. )

  Specific examples of the yellow dye represented by the general formula (YD) of the present invention are shown below, but the yellow dye represented by the general formula (YD) that can be used in the present invention is limited by the following specific examples. It is not something.

  Next, the compound represented by general formula (YE) is demonstrated.

In General Formula (YE), R ^1B and R ^2B each independently represent a hydrogen atom, an optionally substituted alkyl group, an allyl group, an optionally substituted aryl group, or an optionally substituted group. Represents a cycloalkyl group, R ^3B represents a hydrogen atom, an optionally substituted alkyl group, an NR ^5C R ^6C group, an optionally substituted alkoxy group, an optionally substituted alkoxycarbonyl group, a substituted Represents a good aryl group or a C (O) NR ^5D R ^6D group, and R ^4B , R ^5C , R ^5D , R ^6C and R ^6D each independently represents a hydrogen atom or an optionally substituted alkyl group. Or an aryl group which may be substituted.

  Specific examples of the yellow dye represented by the general formula (YE) of the present invention are shown below, but the yellow dye represented by the general formula (YE) that can be used in the present invention is limited by the following specific examples. It is not something.

  The compounds represented by the general formulas (M), (C), (YA) to (YE) are preferably contained in the thermal transfer layer (dye layer) in an amount of 10 to 90% by mass, respectively, and 20 to 80% by mass. % Content is more preferable.

The coating amount of the thermal transfer layer of the thermal transfer sheet (ink sheet) is 0.1 to 1.0 g / m ² (in terms of solid content, hereinafter the coating amount in the present invention is a numerical value in terms of solid content unless otherwise specified. .), More preferably 0.15 to 0.60 g / m ² . The film thickness of the thermal transfer layer is preferably from 0.1 to 2.0 μm, more preferably from 0.1 to 1.0 μm.

The support for the heat-sensitive transfer sheet can be the same as the support for the heat-sensitive transfer image-receiving sheet, and polyethylene terephthalate or the like can be used.
The thickness of the support is preferably 1 to 10 μm, and more preferably 2 to 10 μm. Details of the heat-sensitive transfer sheet are described in, for example, JP-A No. 11-105437, and the descriptions of paragraph numbers 0017 to 0078 are preferably incorporated in the present specification.

The image formed on the receiving layer of the heat-sensitive transfer image-receiving sheet by the heat-sensitive transfer sheet according to the method of the present invention is a dye in which the yellow component of the image is selected from the compounds represented by the general formula (YA) or (YB) It is preferable that the magenta component is a dye made of the compound represented by the general formula (M), and the cyan component is a dye made of the compound represented by the general formula (C).
Specifically, preferably, a thermal transfer layer containing dyes of different colors is coated on the thermal transfer sheet in the longitudinal direction of the sheet in the order of the surface. In this thermal transfer layer, a corresponding dye compound (compound represented by formula (YA), (YB), (M) or (C)) is contained.

Next, the heat transferable protective layer sheet used in the heat-sensitive transfer sheet of the present invention will be described.
(Substrate sheet)
As a base material sheet which comprises the protective layer transfer sheet of this invention, the base material sheet used for the conventional heat transfer sheet can be used. Specific examples of preferable substrate sheets are thin papers such as capacitor paper, glassine paper, and paraffin paper, or high heat resistance such as polyethylene terephthalate, polybutylene terephthalate, polyphenylene sulfide, polyether ketone, polyether sulfone, and polyethylene naphthalate. Polyester, polypropylene, polycarbonate, cellulose acetate, polyethylene derivatives, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyamide, polyimide, polymethylpentene, ionomer, and other plastic stretched or unstretched films or sheets can be used. The surface of the material is subjected to an easy adhesion treatment or the like, or a laminate of these materials. Although the thickness of this base material sheet can be suitably selected according to material so that intensity | strength and heat resistance may become appropriate, the thing about 1-100 micrometers is normally used preferably.

(Protective layer)
The protective layer of the present invention was configured to be a laminate of at least two layers in which a layer mainly composed of an acrylic resin and a layer mainly composed of a polyester resin were provided in this order on at least a base sheet. The acrylic resin of the present invention is a polymer comprising at least one monomer selected from conventionally known acrylate monomers and methacrylate monomers, and may be copolymerized with styrene, acrylonitrile or the like in addition to the acrylic monomer. . A preferable monomer is methyl methacrylate, and the content is preferably 50% by mass or more in terms of the charged mass ratio.

  Examples of the conventionally known acrylic monomers include the following. Methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, butyl acrylate, butyl methacrylate, isobutyl acrylate, isobutyl methacrylate, tertiary butyl acrylate, tertiary butyl methacrylate, isodecyl acrylate, Isodecyl methacrylate, lauryl acrylate, lauryl methacrylate, lauryl tridecyl acrylate, lauryl tridecyl methacrylate, tridecyl acrylate, tridecyl methacrylate, cetyl stearyl acrylate, cetyl stearyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl Methacrylate, octyl acrylate Rate, octyl methacrylate, cyclohexyl acrylate, cyclohexyl methacrylate, benzyl acrylate, benzyl methacrylate, phenoxyethyl acrylate, phenoxyethyl methacrylate, isobornyl acrylate, isobornyl methacrylate, dicyclopentenyl acrylate, dicyclopentenyl methacrylate Methacrylic acid, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl acrylate, diethylaminoethyl methacrylate, Tertiary butyl aminoethyl Acrylate, tert-butylaminoethyl methacrylate, glycidyl acrylate, acrylate, tetrahydrofurfuryl methacrylate, and the like.

  In addition, ethylene diacrylate, ethylene dimethacrylate, diethylene glycol diacrylate, diethylene glycol dimethacrylate, triethylene glycol diacrylate, triethylene glycol dimethacrylate, tetraethylene glycol diacrylate, tetraethylene glycol dimethacrylate, decaethylene glycol diacrylate Acrylate, Decaethylene glycol dimethacrylate, Pentadecaethylene glycol diacrylate, Pentadecaethylene glycol dimethacrylate, Penta contactor ethylene glycol diacrylate, Penta contactor ethylene glycol dimethacrylate, Butylene diacrylate, Butylene dimethacrylate, Allyl acrylate, allyl methacrylate Rate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, 1,6-hexanediol diacrylate, 1,6-hexanediol dimethacrylate, tripropylene glycol diacrylate, tripropylene glycol dimethacrylate, pentaerythritol tetra Examples thereof include acrylate, pentaerythritol tetramethacrylate, dipentaerythritol hexaacrylate, dipentaerythritol hexamethacrylate, neopentyl glycol pentaacrylate, neopentyl glycol pentamethacrylate, phosphazene hexaacrylate, and phosphazene hexamethacrylate. The acrylic resin of the present invention preferably has a molecular weight of 20,000 or more and 100,000 or less. If it is less than 20,000, an oligomer is produced at the time of synthesis and stable performance cannot be obtained, and if it exceeds 100,000, the foil breakage becomes worse during transfer of the protective layer.

  As the polyester resin of the present invention, conventionally known saturated polyester resins can be used. Examples of the acid component of the polyester resin used in the present invention include terephthalic acid, isophthalic acid, orthophthalic acid, 2,6 -Naphthalenedicarboxylic acid tetrahydrophthalic acid, hexahydrophthalic acid, hexahydroisophthalic acid, hexahydroterephthalic acid and the like. Examples of the aliphatic dicarboxylic acid include succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedioic acid, and dimer acid. Examples of the alicyclic dicarboxylic acid include cyclohexane dicarboxylic acid, tricyclodecane dicarboxylic acid, decalin dicarboxylic acid, and the like. These compounds may be methyl esterified or may be acid anhydrides thereof. .

  Furthermore, p- (hydroxyethoxy) benzoic acid, hydroxypivalic acid, γ-butyryllactone, ε-caprolactone, fumaric acid, maleic acid, maleic anhydride, itaconic acid, citraconic acid and the like can be used in combination. . Further, if necessary, a tri- or higher functional polycarboxylic acid such as trimellitic acid, pyromellitic acid or the like and tetracarboxylic acid may be used if it is 10 mol% or less based on the total carboxylic acid component. I can do it. In particular, a structure in which one or more acid components in which a part of an aromatic dicarboxylic acid is substituted with sulfonic acid or a salt thereof is included in one molecular chain, and the upper limit of the amount of these sulfonic acid substitutions (or groups of the salts) is preferable. For example, it is more preferable that it is copolymerized within a range soluble in an organic solvent in that it can be used by mixing with other organic solvent-soluble additives and resins. Preferred aromatic dicarboxylic acids containing these sulfonic acid substitutions (or salts thereof) include sulfoterephthalic acid, 5-sulfoisophthalic acid, 4-sulfophthalic acid, 4-sulfonaphthalene-2,7-dicarboxylic acid, Examples thereof include 5 (4-sulfophenoxy) isophthalic acid and the like, ammonium salts thereof, and metal salts thereof such as lithium, potassium, magnesium, calcium, copper, and iron. Particularly preferred is 5-sodium sulfoisophthalic acid.

  Examples of the polyol component which is another raw material of the polyester used in the present invention include ethylene glycol, 1,2-propylene glycol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1,5- Pentanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 1,9-nonanediol, 2-ethyl-2-butylpropanediol, hydroxypivalic acid neopentyl glycol ester, dimethylolheptane, 2,2,4-trimethyl-1,3-pentanediol is exemplified. Diethylene glycol, triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, neopentyl glycol ethylene oxide adduct, neopentyl glycol propylene oxide adduct may be used as necessary.

  As aromatic-containing glycols, para-xylene glycol, meta-xylene glycol, ortho-xylene glycol, 1,4-phenylene glycol, ethylene oxide adduct of 1,4-phenylene glycol, bisphenol A, ethylene oxide adduct of bisphenol A and propylene Examples thereof include glycols obtained by adding 1 to several moles of ethylene oxide or propylene oxide to two phenolic hydroxyl groups of bisphenols such as oxide adducts. Examples of the alicyclic diol component include tricyclodecane diol, tricyclodecane dimethylol, tricyclodecane dimethanol (TCD-M), cyclohexane diol, 1,4-cyclohexane dimethanol, hydrogenated bisphenol A, and hydrogenation. Examples thereof include ethylene oxide and propylene oxide adducts of bisphenol A. The polyester resin preferably has a glass transition temperature of 50 to 120 ° C., and a molecular weight of preferably 2,000 to 40,000, and more preferably 4,000 to 20,000 when the protective layer is transferred. Is better and more preferable.

  In the protective layer transfer sheet of the present invention, the protective layer containing a polyester resin as a main component and / or an adhesive layer can contain an ultraviolet absorber, and as the ultraviolet absorber, a conventionally known inorganic ultraviolet ray can be used. Absorbers and organic ultraviolet absorbers can be used. Organic UV absorbers include salicylates, benzophenones, benzotriazoles, triazines, substituted acrylonitriles, nickel chelates, hindered amines, and other non-reactive UV absorbers. For example, an addition polymerizable double bond such as a vinyl group, an acryloyl group, or a methacryloyl group, or an alcoholic hydroxyl group, an amino group, a carboxyl group, an epoxy group, an isocyanate group, or the like is introduced into the agent. A plastic resin copolymerized or grafted can be used. Among these ultraviolet absorbers, benzophenone, benzotriazole, and triazine are particularly preferable. Depending on the characteristics of the dye used for image formation, these UV absorbers may be used in combination with different ones so as to cover the effective UV absorption wavelength range, or non-reactive UV absorbers may be used as UV absorbers. It is preferable to use a mixture of a plurality of different structures so as not to precipitate.

(Release layer)
In the protective layer transfer sheet of the present invention, a release layer can be formed between the base sheet and the protective layer when the protective layer is difficult to peel from the base sheet during thermal transfer. In other words, a release layer can be provided on the base sheet, and the base sheet can be released. The release layer includes, for example, waxes, silicone wax, silicone resin, fluorine resin, acrylic resin, polyvinyl alcohol resin, cellulose derivative resin, urethane resin, acetic acid vinyl resin, acrylic vinyl ether resin, maleic anhydride resin, and It can be formed by applying and drying a coating solution containing at least one copolymer of these resin groups by a conventionally known method such as gravure coating or gravure reverse coating. Among the above resins, acrylic resin is preferably a resin such as acrylic acid or methacrylic acid, or a resin copolymerized with other monomers, and is excellent in adhesion to the base sheet and releasability from the protective layer. ing.

  The release layer can be appropriately selected from those that move to the transfer target during thermal transfer, those that remain on the base sheet side, or those that cohesively break down, but the release layer is non-transferable, The surface glossiness and the transfer of the protective layer may be such that the release layer remains on the substrate sheet side by thermal transfer, and the interface between the release layer and the thermal transferable protective layer becomes the surface of the protective layer after the thermal transfer. Since it is excellent in terms of stability and the like, it is preferably performed. The release layer can be formed by a conventionally known coating method, and a thickness of about 0.5 to 5 μm is sufficient in a dry state. If a matte protective layer is desired after transfer, various types of particles are included in the release layer, or the surface of the release layer on the protective layer side is matted to form a surface mat. You can also If the base sheet and the protective layer are peelable, the protective layer can be peeled directly from the base sheet by thermal transfer without providing the release layer.

(Adhesive layer)
In the present invention, an adhesive layer is preferably provided on the outermost surface of the protective layer, which is a laminate of at least two layers of the protective layer transfer sheet, in order to improve the adhesion of the protective layer to the transfer target. As the adhesive layer, any of conventionally known pressure-sensitive adhesives and heat-sensitive adhesives can be used, but it is more preferably formed from a thermoplastic resin having a glass transition temperature of 50 ° C. to 80 ° C., for example, an ultraviolet absorbing resin, Appropriate glass transition temperature is selected from resins with good thermal adhesive properties such as acrylic resin, vinyl chloride-vinyl acetate copolymer resin, epoxy resin, polyester resin, polycarbonate resin, butyral resin, polyamide resin, vinyl chloride resin, etc. It is preferable to select what has.

  As the ultraviolet absorbing resin, for example, a resin obtained by reacting and bonding a reactive ultraviolet absorber to a thermoplastic resin or an ionizing radiation curable resin can be used. More specifically, addition-polymerizable double-reactive organic UV absorbers such as salicylates, benzophenones, benzotriazoles, substituted acrylonitriles, nickel chelates, hindered amines, etc. Examples thereof include those in which a reactive group such as a bond (for example, a vinyl group, an acryloyl group, a methacryloyl group), an alcoholic hydroxyl group, an amino group, a carboxyl group, an epoxy group, or an isocyanate group is introduced.

  The adhesive layer is composed of the above-described resins, organic ultraviolet absorbers such as benzophenone compounds, benzotriazole compounds, oxalic acid anilide compounds, cyanoacrylate compounds, salicylate compounds, zinc, titanium, cerium, and the like. Additives of fine particles having an inorganic ultraviolet absorbing ability such as oxides of tin, iron and the like can be added. Further, as an additive, a coloring pigment, a white pigment, an extender pigment, a filler, an antistatic agent, an antioxidant, a fluorescent whitening agent, and the like can be used as necessary. By applying and drying a resin that constitutes the adhesive layer as described above and, if necessary, a coating liquid to which the above additives are added, a thickness of preferably about 0.5 to 10 μm in a dry state. To form an adhesive layer.

The heat transferable protective sheet of the present invention preferably has an absorption maximum in a wavelength range of 330 to 370 nm, and the absorption density at the maximum absorption wavelength is preferably 0.8 or more.
In addition, it is preferable that the absorption wavelength and absorption density here are in a protective sheet.

The image forming system of the present invention forms a thermal transfer image by superimposing the receiving layer of the thermal transfer image receiving sheet and the thermal transfer layer of the thermal transfer sheet so as to contact each other and applying thermal energy according to the image signal. To do.
Specific image formation can be performed in the same manner as described in, for example, JP-A-2005-88545. In the present invention, the printing time is preferably less than 15 seconds, and more preferably 5 to 12 seconds, from the viewpoint of shortening the time until the printed matter is provided to the consumer.
The system of the present invention can be used, for example, in a printer, a copying machine or the like using a thermal transfer recording system.
As the means for applying thermal energy at the time of thermal transfer, any conventionally known means for applying can be used. For example, recording is performed by a recording device such as a thermal printer (for example, product name, video printer VY-100, manufactured by Hitachi, Ltd.). By controlling the time, the intended purpose can be sufficiently achieved by applying thermal energy of about 5 to 100 mJ / mm ² .
The heat-sensitive transfer image-receiving sheet of the present invention can be applied to various uses such as a sheet- or roll-shaped heat-sensitive transfer image-receiving sheet, cards, and transmission-type manuscript preparation sheets capable of thermal transfer recording by appropriately selecting a support. You can also

  EXAMPLES Hereinafter, although this invention is demonstrated in detail based on an Example, this invention is not limited to these. In Examples, “part” or “%” is based on mass unless otherwise specified.

[Preparation of ink sheet]
(Preparation of ink sheet D1)
A polyester film having a thickness of 6.0 μm (Lumirror, trade name, manufactured by Toray Industries, Inc.) was used as a base film. A heat-resistant slip layer (thickness 1 μm) was formed on the back side of the film, and yellow, magenta and cyan compositions having the following compositions were applied to the surface side in a single color (coating amount 1 g / m ² during dry film formation).
Yellow ink Dye compound (YC-1) 4.5 parts by mass Polyvinyl butyral resin 4.5 parts by mass (ESREC BX-1, trade name, manufactured by Sekisui Chemical Co., Ltd.)
Methyl ethyl ketone / toluene (mass ratio 1/1) 90 parts by mass Magenta ink Dye compound (MS-1) 4.5 parts by mass Polyvinyl butyral resin 4.5 parts by mass (ESREC BX-1, trade name, Sekisui Chemical Co., Ltd.) Made)
Methyl ethyl ketone / toluene (mass ratio 1/1) 90 parts by mass cyan ink dye compound (CS-1) 4.5 parts by mass Polyvinyl butyral resin 4.5 parts by mass (ESREC BX-1, trade name, Sekisui Chemical Co., Ltd.) Made)
90 parts by mass of methyl ethyl ketone / toluene (mass ratio 1/1)

(Preparation of ink sheet D2)
In the production of the ink sheet D1, the ink sheet D2 of the present invention was produced in the same manner as the production of the ink sheet D1, except that the dye compound MS-1 was replaced with M-2 and CS-1 was replaced with C-10.

(Preparation of ink sheet D3)
In the production of the ink sheet D1, the ink sheet D2 of the present invention was produced in the same manner as the production of the ink sheet D1, except that the dye compound MS-1 was replaced with M-8 and CS-1 was replaced with C-10.

(Preparation of ink sheet D4)
An ink sheet D4 of the present invention was prepared in the same manner as the ink sheet D2 except that the dye compound YC-1 was replaced with YD-1 in the preparation of the ink sheet D2.

(Preparation of ink sheet D5)
Ink sheet D5 of the present invention was prepared in the same manner as ink sheet D2 except that dye compound YC-1 was replaced with YE-2 in preparation of ink sheet D2.

(Preparation of ink sheet D6)
An ink sheet D6 of the present invention was prepared in the same manner as the ink sheet D2 except that the dye compound YC-1 was replaced with the exemplified compound (7) of the general formula (YA) in the preparation of the ink sheet D2.

(Preparation of ink sheet D7)
In the production of the ink sheet D2, the ink sheet D7 of the present invention was produced in the same manner as the production of the ink sheet D2, except that the dye compound YC-1 was replaced with YB- (1).

  The structures of dye compounds MS-1 and CS-1 used for the production of the ink sheet D1 are shown below.

[Preparation of protective layer sheet]
(Preparation of protective layer sheet P1)
A protective layer and an adhesive layer having the following composition were applied to the same polyester film used for preparing the ink sheet. The coating amount at the time of dry film protective layer 1 g / m ^2, the adhesive layer 0.7 g / m ²⁾ was. The adhesive layer was applied on the protective layer after coating and drying.
Protective layer Acrylic resin 20 parts by mass (Dianar BR-80, trade name, manufactured by Mitsubishi Rayon Co., Ltd.)
Methyl ethyl ketone / toluene (mass ratio 1/1) 80 parts by mass adhesive layer polyester resin 30 parts by mass (Byron 220, trade name, manufactured by Toyobo Co., Ltd.)
Methyl ethyl ketone / toluene (mass ratio 1/1) 70 parts by mass

Production of protective layer sheet P2 A protective layer sheet P2 was produced in the same manner as the production of the protective layer sheet P2, except that in the production of the protective layer sheet P1, Tinuvin 900 (trade name, manufactured by Ciba Geigy Co., Ltd.) was added to the protective layer. The absorption maximum wavelength of the protective layer sheet P2 was 348 nm, and the absorption at the absorption maximum was 0.6.

Production of protective layer sheet P3 In production of the protective layer sheet P2, the protective layer sheet P2 except that the addition amount of Tinuvin 900 (trade name, manufactured by Ciba Geigy Co., Ltd.) was increased so that the absorption at 348 nm was 0.8. A protective layer sheet P3 was produced in the same manner as in the above.

[Preparation of thermal transfer image-receiving sheet]
Preparation of image-receiving sheet 101 A synthetic paper (YUPO FPG200, thickness 200 μm, trade name, manufactured by YUPO Corporation) was used as a support, and a white intermediate layer having the following composition was applied to this surface in the order of a bar coater. went. The coating amount at the time of each drying was coated as a white intermediate layer 1.0 g / m ^2, the receiving layer 4.0 g / m ^2, drying each layer 110 ° C., it was carried out for 30 seconds.
White intermediate layer Polyester resin (Byron 200, trade name, manufactured by Toyobo Co., Ltd.) 10 parts Optical brightener (Uvitex OB, trade name, manufactured by Ciba Geigy) 1 part Titanium oxide 30 parts Methyl ethyl ketone / toluene (mass ratio 1/1) 90 parts Receiving layer 100 parts vinyl chloride-vinyl acetate resin (Solvine A, trade name, manufactured by Nissin Chemical Industry Co., Ltd.)
Amino-modified silicone 5 parts (Shin-Etsu Chemical Co., Ltd., trade name, X22-3050C)
Epoxy-modified silicone 5 parts (Shin-Etsu Chemical Co., Ltd., trade name, X22-300E)
400 parts of methyl ethyl ketone / toluene (mass ratio 1/1)

Preparation of Image Receiving Sheet 102 The surface of the paper support laminated on both sides with polyethylene was subjected to corona discharge treatment, and then a gelatin subbing layer containing sodium dodecylbenzenesulfonate was provided. On top of this, in the state in which the heat insulating layer and the receiving layer having the following composition are laminated in this order from the support side, a multilayer is formed by the method illustrated in FIG. 9 described in US Pat. No. 2,761,791. Application was performed. Immediately after application, the film was dried at 50 ° C. for 16 hours. Each of the coating amounts at the time of drying was applied such that the heat insulating layer was 15 g / m ² and the receiving layer was 4.0 g / m ² .
Receiving layer 48 parts of vinyl chloride latex (Viniblanc 900, trade name, manufactured by Nissin Chemical Industry Co., Ltd.)
Gelatin 3 parts Wax 1 part (EMUSTAR-042X, trade name, manufactured by Nippon Seiki Co., Ltd.)
Thermal insulation layer Hollow polymer latex 563 parts (MH5055, trade name, manufactured by Nippon Zeon Co., Ltd.)
120 parts of gelatin

Preparation of Image Receiving Sheet 103 A paper support surface laminated on both sides with polyethylene was subjected to corona discharge treatment, and then a gelatin subbing layer containing sodium dodecylbenzenesulfonate was provided. On this, a heat insulating layer having the same composition as the image receiving sheet 102 and an intermediate layer made of only gelatin are laminated in this order from the support side in FIG. 9 described in US Pat. No. 2,761,791. Multilayer coating was performed by the exemplified method. Immediately after application, the film was dried at 50 ° C. for 16 hours. Each of the coating amounts at the time of drying was applied such that the heat insulating layer was 15 g / m ² and the intermediate layer was 0.2 g / m ² . On the intermediate layer of the obtained sample, a receiving layer having the same composition as the image receiving sheet 101 was applied by a bar coater. The demand layer was coated so that the coating amount at the time of drying was 4.0 g / m ^2, and drying was performed at 110 ° C. for 30 seconds immediately after coating.

Preparation of the image receiving sheet 104 The image receiving sheet 104 was prepared in the same manner as the image receiving sheet 102 except that the gelatin of the heat insulating layer was changed to a water-soluble polyester resin (Vylonal MD1200, trade name, manufactured by Toyobo) in the preparation of the image receiving sheet 102. did.

(Image formation)
Ink sheets D1 to D7, protective layer sheets P1 and P2, and the image receiving sheets 101 to 104 are combined as shown in Tables 1 and 2 to produce a thermal transfer material, and a sublimation printer DPB1500 (trade name, manufactured by Nidec Copal) ), And a black solid image and a yellow single color image were output.

(Maximum transfer density)
The Visual density of the black image obtained under the above conditions was measured with a Photographic Densitometer (trade name, manufactured by X-Rite Incorporated).

(Light fastness evaluation test)
Optical density (Dmax) measurement of black solid part and xenon light (96000lux) are irradiated to the image sample for 144 hours, the image density after irradiation is measured with a reflection densitometer, the image density before irradiation is set to 100%, The concentration residual ratio was calculated.

(Yellow dye reverse transfer test)
Measure the yellow density in a black single color output or black image with a Photographic Densitometer (product name, manufactured by X-Rite Incorporated). What is the yellow density in the black image output relative to the maximum yellow density in the yellow single color output? The degree of reverse transfer of the yellow dye was evaluated based on whether or not the ratio decreased.

  The obtained results are shown in Tables 3 and 4 below.

  From the results of Tables 3 and 4 above, it was found that the thermal transfer material having the constitution of the present invention had a higher maximum density than the comparative example and was excellent in dye transferability. Each sample of the present invention was excellent in light resistance. Furthermore, it was found that the thermal transfer material having the constitution of the present invention can obtain an image having a small reverse transfer ratio of the yellow dye and a good color balance.

Claims (9)

A thermal transfer image-receiving sheet having at least one receiving layer on the support and having at least one heat insulating layer containing a hollow polymer and a hydrophilic polymer between the receiving layer and the support; A magenta dye having at least one compound represented by the following general formula (M), wherein the magenta dye contained in the magenta heat transfer layer contains at least one compound represented by the following general formula (M): And a heat-sensitive transfer sheet in which the cyan dye contained in is only a compound represented by the following general formula (C):

(In the general formula (M), D ^{1 to} D ⁵ are each independently a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an aryl group, an aryloxy group, a cyano group, an acylamino group, a sulfonylamino group, a ureido group, Represents an alkoxycarbonylamino group, an alkylthio group, an arylthio group, an alkoxycarbonyl group, a carbamoyl group, a sulfamoyl group, a sulfonyl group, an acyl group or an amino group, and D ⁶ and D ⁷ each independently represents a hydrogen atom, an alkyl group or an aryl group. D ⁶ and D ⁷ may be bonded to each other to form a ring, and D ³ and D ⁶ or / and D ⁴ and D ⁷ may be bonded to each other to form a ring. Y and Z represent ═C (D ⁸ ) — or a nitrogen atom, where D ⁸ represents a hydrogen atom, an alkyl group, an aryl group, an alkoxy group, an aryloxy group. When X and Y are = C (D ⁸ )-, or when Y and Z are = C (D ⁸ )-, the two D ⁸ are bonded to each other to be saturated or unsaturated. (Saturated carbocycle may be formed. Each of these groups may further have a substituent.)

(In General Formula (C), D ^{9 to} D ¹⁶ are each independently a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an aryl group, an aryloxy group, a cyano group, an acylamino group, a sulfonylamino group, a ureido group, Represents an alkoxycarbonylamino group, an alkylthio group, an arylthio group, an alkoxycarbonyl group, a carbamoyl group, a sulfamoyl group, a sulfonyl group, an acyl group or an amino group, and D ¹⁷ and D ¹⁸ each independently represents a hydrogen atom, an alkyl group or an aryl group. D ¹⁷ and D ¹⁸ may be bonded to each other to form a ring, and D ¹⁴ and D ¹⁷ or / and D ¹⁵ and D ¹⁸ may be bonded to each other to form a ring. Each group may further have a substituent.) 2. The image according to claim 1, wherein at least one of the yellow dyes in the yellow thermal transfer layer of the thermal transfer sheet is a compound represented by any one of the following general formulas (YA) to (YE). Forming method.

(In the general formula (YA), R ¹¹ represents a monovalent substituent, R ¹² represents a hydrogen atom or a monovalent substituent, and Ar ¹ is a group selected from the group (1) of the following heterocyclic group. X represents an atomic group necessary for ring formation.)

(In the heterocyclic group (1), R ⁶¹ , R ⁶² , R ⁶³ , R ⁶⁴ and R ⁶⁵ each independently represents a hydrogen atom or a substituent.)

(In the general formula (YB), R ¹ , R ² , R ³ , R ⁴ and R ⁶ each independently represent a hydrogen atom or a monovalent substituent, and R ⁵ represents a monovalent substituent.)

(In the general formula (YC), R ^A , R ^B , R ^C , R ^D and R ^E are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group, an alkoxy group, an alkoxy group. An alkoxy group, an alkoxycarbonyl group, a thioalkoxy group, an alkylsulfonyl group, an amino group, a substituted or unsubstituted phenoxy group, or a substituted or unsubstituted thiophenoxy group, wherein R ^F and R ^G are each independently hydrogen; An atom, an alkyl group, an alkoxyalkyl group, a cycloalkyl group, an allyl group, an aryl group which may have a substituent, an aralkyl group, a furfuryl group, a tetrahydrofurfuryl group, or a hydroxyalkyl group.

(In General Formula (YD), R ^1A represents an allyl group or an alkyl group, R ^2A represents a substituted or unsubstituted alkyl group or an aryl group, and A represents —CH ₂ —, —CH ₂ CH ₂ —, — _{CH 2 CH 2 O -, -} CH 2 CH 2 OCH 2 - or _{-CH 2 CH 2 OCH 2 CH 2} -. represents, R ^3A represents an alkyl group have each of these groups are further substituted May be good.)

(In General Formula (YE), R ^1B and R ^2B are each independently a hydrogen atom, an optionally substituted alkyl group, an allyl group, an optionally substituted aryl group, or an optionally substituted group. Represents a cycloalkyl group, R ^3B represents a hydrogen atom, an optionally substituted alkyl group, an NR ^5C R ^6C group, an optionally substituted alkoxy group, an optionally substituted alkoxycarbonyl group, a substituted Represents a good aryl group or a C (O) NR ^5D R ^6D group, wherein R ^4B , R ^5C , R ^5D , R ^6C and R ^6D each independently represents a hydrogen atom, an optionally substituted alkyl group, Or, it represents an optionally substituted aryl group.)   The at least one kind of yellow dye in the yellow thermal transfer layer of the thermal transfer sheet is a compound represented by either the general formula (YA) or (YB). Image forming method. In the general formula (M), X and Z are nitrogen atoms, and Y is ═C (D ⁸ ) — (where D ⁸ is a hydrogen atom, an alkyl group, an aryl group, an alkoxy group, an aryloxy group, or The image forming method according to claim 1, wherein the image forming method represents an amino group.   5. The image according to claim 1, wherein in the heat-sensitive transfer sheet, at least three kinds of heat-transfer layers composed of yellow, magenta, and cyan are formed in a surface sequential manner on a support. Forming method.   The image forming method according to claim 1, wherein the thermal transfer sheet further has a protective layer capable of thermal transfer.   The heat-transferable protective layer has an absorption maximum in any range of wavelengths from 330 to 370 nm, and an absorption density at the maximum absorption wavelength is 0.8 or more. Image forming method.   The image forming method according to claim 1, wherein at least one hydrophilic polymer contained in the heat insulating layer is gelatin in the heat-sensitive transfer image-receiving sheet.   9. The image forming method according to claim 1, wherein the thermal transfer layer of the thermal transfer sheet and the receiving layer of the thermal transfer image receiving sheet are in contact with each other, and thermal energy corresponding to an image signal from the thermal head is formed. An image forming method comprising forming an image by forming an image by providing