JP4778846B2 - Thermal transfer image-receiving sheet - Google Patents

Description

The present invention relates to a sublimation type thermal transfer image-receiving sheet (hereinafter simply referred to as a thermal transfer image-receiving sheet) , and more particularly to a thermal transfer image-receiving sheet for providing a good image having a high transfer density and little image unevenness.

  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 compared to silver halide photography, being directly visible from digital data, and being easy to duplicate.

  In this dye diffusion transfer recording system, a heat-sensitive transfer sheet (hereinafter referred to as an ink sheet) containing a dye is superposed on a heat-sensitive transfer image-receiving sheet (hereinafter also referred to as an image-receiving sheet), and then heat generation is controlled by an electrical signal. The ink sheet is heated by a thermal head to transfer the dye in the ink sheet to the image receiving sheet, and image information is recorded. By recording three colors of cyan, magenta, and yellow, the color is recorded. A color image having a continuous change in shading can be transferred and recorded.

In such a dye diffusion transfer type recording system, it has long been known that it is important to give the image receiving sheet high heat insulation and cushioning in order to obtain a good image (for example, non-patent literature). 1 and 2).
Therefore, a composite support using a biaxially stretched polyolefin film containing microvoids may be used as the base material of the image receiving sheet in order to provide heat insulation and cushioning properties (for example, Patent Documents 1 and 2). However, in this method, the residual stress at the time of stretching may be relaxed and contracted by heat at the time of printing or heat at the time of coating the image receiving layer, which may cause problems such as wrinkles or curls on the image receiving sheet. .
As other methods for imparting heat insulating properties and cushioning properties to the image receiving sheet, for example, a foamed layer made of a resin and a foaming agent (for example, Patent Document 3) or a porous layer containing a hollow polymer between the support and the receiving layer A method for forming a layer having a high cushioning property (for example, Patent Document 4) is also known. Since these methods can form a heat insulating layer on the substrate by a coating method, the image receiving sheet seen in the method using the composite support using the biaxially stretched polyolefin film containing the microvoids is wrinkled and Although there is an advantage that curling can be suppressed, it is generally difficult to obtain a uniform and smooth image-receiving sheet, and problems such as poor transfer may occur.
In order to solve this problem, an image receiving sheet is disclosed in which the heat insulating layer is composed of a layer mainly composed of a hollow polymer and an organic solvent-resistant polymer (Patent Document 5), but with a sufficient level. Is hard to say. Further, when forming an intermediate layer containing a resin containing hollow particles as a main component on a sheet-like base material, after applying the intermediate layer-forming paint to the sheet-like base material, the coated surface is pressed against a cast drum. Although a method (Patent Document 6) for forming an image receiving sheet is disclosed, although such a method can provide sufficient smoothness, the manufacturing process becomes complicated and disadvantageous in terms of productivity.

In addition, the image receiving sheet used in this method has a structure in which a receiving layer for transferring the transferred dye is formed on a support, and generally the adhesion between the image receiving sheet and the ink sheet is improved. In order to enhance, a layer having high cushioning properties such as a foamed layer made of a resin and a foaming agent or a porous layer containing a hollow polymer is formed between the support and the receiving layer (for example, Patent Document 7 or 8). reference).
For example, in Patent Document 7, after an intermediate layer mainly composed of hollow particles and an organic solvent-resistant polymer is applied and dried on a support, an organic solvent-based resin coating solution is used. Forming a receiving layer is disclosed. Here, the organic solvent-resistant polymer used in the intermediate layer plays a role of preventing the hollow particles used in the intermediate layer from dissolving in the organic solvent of the receiving layer. However, the heat-sensitive transfer image-receiving sheet in which the receiving layer is formed of an organic solvent-based resin coating solution has a problem that the sensitivity is insufficient and the cost is high, and improvement in image quality and transfer density is also desired. It was.

  Patent Document 8 discloses a heat-sensitive transfer image-receiving sheet having a layer in which hollow spherical pigments are dispersed and an image-receiving layer (receiving layer). However, this heat-sensitive transfer image-receiving sheet has a problem that blur occurs in an image after image transfer.

US Pat. No. 866,282 JP-A-3-268998 Japanese Patent No. 2554196 Japanese Patent No. 2726040 Japanese Patent No. 3226167 JP-A-5-8572 Japanese Patent Laid-Open No. 11-321128 JP-A-2-89690 “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

  An object of the present invention is to provide a thermal transfer image-receiving sheet having a high transfer density and few image defects at a low cost.

  As a result of intensive studies, the inventors have used a support having a polyolefin resin layer on both sides of a base paper or at least a side having a receiving layer, and forming a heat insulating layer containing a hollow polymer thereon. Thus, it has been found that a thermal transfer image-receiving sheet having a high transfer density and few image defects can be provided at low cost. The present invention has been made based on such findings.

That is, it has been found that the above problem can be solved by the following means.
(1) It has at least one receiving layer containing a polymer latex of vinyl chloride acrylic copolymer on the support, and at least one layer between the receiving layer and the support has a particle size of 0.1 to 0.1. 2 μm, having a non-foaming hollow polymer latex formed of polystyrene resin, acrylic resin or styrene-acrylic resin and at least one water-soluble polymer or polymer latex, and the support is on both sides of the base paper or at least receptive layer polyolefin resin layer on the surface on the side provided with, and the surface of the receptive layer provided side, Ri 70 g / m ² or less der coating weight is 5 g / m ² or more polyolefin resin layers The thickness of the base paper is 50 μm or more and 300 μm or less, the density of the base paper is 0.9 g / m ³ or more and 1.1 g / m ³ or less, and the thickness of the support is 10 A sublimation type thermal transfer image-receiving sheet, characterized in that it is 0 μm or more and 350 μm or less .
(2) Sublimation type thermal transfer image receiving image according to item (1), wherein the center line average roughness (Ra) of the surface of the support on which the receiving layer is provided is 0.5 μm or less. Sheet.
(3) The sublimation type thermal transfer image-receiving sheet according to item (1) or (2), wherein the polymer latex in the receptor layer has a vinyl chloride monomer ratio of 50 to 95%.
(4) The sublimation type sensation according to any one of (1) to (3), wherein the polymer latex in the receiving layer is a polymer latex of a copolymer of vinyl chloride and alkyl acrylate. Thermal transfer image receiving sheet.
(5) The sublimation type thermal transfer image-receiving sheet according to any one of (1) to (4), wherein the heat insulating layer contains a water-soluble polymer.
(6) The sublimation type thermal transfer image-receiving sheet as described in any one of (1) to (4), wherein the heat insulating layer contains gelatin.
(7) The sublimation type thermal transfer image-receiving sheet described in any one of (1) to (6), wherein the receptor layer contains a water-soluble polymer.
(8) The sublimation type thermal transfer image-receiving sheet described in any one of (1) to (6), wherein the receiving layer contains gelatin.
(9) The sublimation type thermal transfer image-receiving sheet according to any one of (1) to (8) , wherein the polyolefin resin layer of the support is polyethylene.
(10) The sublimation type thermal transfer image-receiving sheet according to any one of (1) to (9) , wherein a basis weight of the base paper of the support is from 50 g to 300 g.
(11) The receiving layer and / or the heat insulating layer contains a compound capable of crosslinking the water-soluble polymer, and a part or all of the water-soluble polymer is crosslinked (1) The sublimation type thermal transfer image-receiving sheet according to any one of (10 ) to (10) .
(12) The sublimation type thermal transfer according to any one of (1) to (11), wherein an undercoat layer containing a latex and a binder resin is provided between the support and the heat insulating layer. Image receiving sheet.
(13)
The sublimation type thermal transfer image-receiving sheet according to any one of (1) to (12), wherein a charge adjusting layer is provided on the back side of the support.
(14) The on a support having a polyolefin resin layer on the small side of the surface provided with the receptive layer even without the base paper, simultaneous multilayer coating liquid of the heat insulating layer and the coating liquid of the receiving layer in this order manufactured applied, characterized in Rukoto such by (1) sublimation type thermal transfer image-receiving sheet according to any one of - (13).

  The heat-sensitive transfer image-receiving sheet of the present invention is characterized by a high transfer density and few image defects. Further, according to the present invention, it is possible to provide a thermal transfer image receiving sheet capable of obtaining a glossy and high quality image.

The thermal transfer image receiving sheet of the present invention will be described in detail below.
The description of the constituent elements described below may be made based on typical embodiments of the present invention, but the present invention is not limited to such embodiments. In the present specification, a numerical range represented by using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.

(Layer structure of thermal transfer image-receiving sheet)
The heat-sensitive transfer image-receiving sheet used in the present invention has at least a dye receiving layer (receiving layer) and a heat insulating layer formed on a support. 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. Moreover, it is preferable that the heat insulation layer is formed between the base layer and the support body. Furthermore, a curl adjusting layer, a writing layer, and a charge adjusting layer are preferably formed on the back side of the support. Each layer is applied by a general method such as roll coat, bar coat, gravure coat, gravure reverse coat, die coat, slide coat, curtain coat, etc., but multiple layers such as slide coat, curtain coat etc. are applied simultaneously in multiple layers. A method that can be used is preferred.

(Receptive layer)
The receiving layer serves to receive the dye transferred from the ink sheet and maintain the formed image. The image-receiving sheet used in the present invention has at least one receiving layer having a thermoplastic receiving polymer capable of receiving at least a dye.
The accepting polymer is preferably used as a polymer latex dispersed in a water-soluble dispersion medium. Furthermore, the receiving layer preferably contains a water-soluble polymer in addition to the polymer latex. By including a polymer latex and a water-soluble polymer, a water-soluble polymer that is difficult to be dyed to the dye can be present between the polymer latexes, and the dye dyed to the polymer latex can be prevented from diffusing. Therefore, it is possible to reduce a change in sharpness of the receiving layer with time and to form a recorded image with a small change in transfer image with time.
For the receiving layer, in addition to the polymer latex of the receiving polymer, for example, a polymer latex having other functions can be used in combination for the purpose of adjusting the elastic modulus of the film.

<Polymer latex>
The polymer latex used in the present invention will be described.
The polymer latex that can be used in the receiving layer in the heat-sensitive transfer image-receiving sheet of the present invention is obtained by dispersing a water-insoluble hydrophobic polymer as fine particles in a water-soluble dispersion medium. As the polymer latex, several different types of polymer latex may be used in combination. However, the polymer latex used in the present invention contains at least vinyl chloride as a monomer unit, that is, a latex containing a repeating unit obtained from vinyl chloride. At least one type is used.
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, Ikuo Kataoka, Junichi Suzuki, Keiji Kasahara, “Application of Synthetic Latex”, Takashi Published by Molecular Press (1993), Soichi Muroi, “Synthetic Latex Chemistry”, published by High Polymer Press (1970), supervised by Yoshiaki Mitsuzawa, “Development and application of water-based coating materials”, CM Publishing ( 2004) and JP-A-64-538. The average particle size of the dispersed particles is preferably 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 so-called core / shell type latex in addition to a normal uniform polymer latex. In this case, it may be preferable to change the glass transition temperature between the core and the shell. The glass transition temperature of the polymer latex of 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.
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. The homopolymer glass transition temperature value (Tgi) of each monomer may be the value of “Polymer Handbook (3rd Edition)” (by J. Brandrup, EH Immergut (Wiley-Interscience, 1989)).

Preferred embodiments of the polymer latex containing repeating units obtained from vinyl chloride used in the receiving layer in the present invention include polyvinyl chlorides, copolymers containing vinyl chloride as monomer units, such as vinyl chloride vinyl acetate copolymers, A vinyl chloride acrylic copolymer polymer can be preferably used . In the present invention, a polymer latex of a vinyl chloride acrylic copolymer is essential . In this case, the ratio of the vinyl chloride monomer is preferably 50% or more and 95% or less. These polymers may be linear polymers, branched polymers, crosslinked polymers, so-called homopolymers obtained by polymerizing a single monomer, or copolymers obtained by polymerizing two or more types of monomers. In the case of a copolymer, it may be a random copolymer or a block copolymer. These polymers have a number average molecular weight of 5,000 to 1,000,000, preferably 10,000 to 500,000. If the molecular weight is too small, the mechanical strength of the layer containing the latex is insufficient, and if it is too large, the film formability is poor and this is not preferred. A crosslinkable polymer latex is also preferably used.

  Polymer latex containing a repeating unit obtained from vinyl chloride 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).

  There are no particular restrictions on polymer latexes having other structures used in combination with latex containing monomer units of vinyl chloride, but acrylic polymers, polyesters, rubbers (eg SBR resin), polyurethanes, polychlorinated Hydrophobic polymers such as vinyls, polyvinyl acetates, polyvinylidene chlorides and polyolefins can be preferably used. These polymers may be linear polymers, branched polymers, crosslinked polymers, so-called homopolymers obtained by polymerizing a single monomer, or copolymers obtained by polymerizing two or more types of monomers. In the case of a copolymer, it may be a random copolymer or a block copolymer. These polymers have a number average molecular weight of 5,000 to 1,000,000, preferably 10,000 to 500,000. If the molecular weight is too small, the mechanical strength of the layer containing the latex is insufficient, and if it is too large, the film formability is poor and this is not preferred. A crosslinkable polymer latex is also preferably used.

  The monomer used in combination with the synthesis of a polymer latex having another structure used in combination with a latex containing monomer units used in the present invention is not particularly limited, and is a normal radical polymerization or ionic polymerization method. As those that can be polymerized, the monomer groups (a) to (j) shown below can be preferably used. Polymer monomers can be synthesized by selecting these monomers independently and freely in combination.

-Monomer group (a)-(j)-
(A) Conjugated dienes: 1,3-pentadiene, isoprene, 1-phenyl-1,3-butadiene, 1-α-naphthyl-1,3-butadiene, 1-β-naphthyl-1,3-butadiene, cyclo Pentadiene and the like.
(B) Olefins: ethylene, propylene, vinyl chloride, vinylidene chloride, 6-hydroxy-1-hexene, 4-pentenoic acid, methyl 8-nonenoate, vinylsulfonic acid, trimethylvinylsilane, trimethoxyvinylsilane, 1,4- Divinylcyclohexane, 1,2,5-trivinylcyclohexane, etc.

  (C) α, β-unsaturated carboxylic acid esters: alkyl acrylate (eg, methyl acrylate, ethyl acrylate, butyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate, dodecyl acrylate, etc.), substituted alkyl acrylate (eg, 2-chloro Ethyl acrylate, benzyl acrylate, 2-cyanoethyl acrylate, etc.), alkyl methacrylate (eg, methyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, dodecyl methacrylate, etc.), substituted alkyl methacrylate (eg, 2-hydroxyethyl methacrylate, glycidyl methacrylate) Glycerin monomethacrylate, 2-acetoxyethyl methacrylate, tetrahydrofurfurylme Chryrate, 2-methoxyethyl methacrylate, polypropylene glycol monomethacrylate (polyoxypropylene added mole number = 2 to 100), 3-N, N-dimethylaminopropyl methacrylate, chloro-3-N, N, N-trimethyl Ammoniopropyl methacrylate (2-carboxyethyl methacrylate, 3-sulfopropyl methacrylate, 4-oxysulfobutyl methacrylate, 3-trimethoxysilylpropyl methacrylate, allyl methacrylate, 2-isocyanatoethyl methacrylate, etc.), unsaturated dicarboxylic acid Derivatives (eg, monobutyl maleate, dimethyl maleate, monomethyl itaconate, dibutyl itaconate, etc.), polyfunctional esters (eg, ethylene glycol diacrylate) , Ethylene glycol dimethacrylate, 1,4-cyclohexanediacrylate, pentaerythritol tetramethacrylate, pentaerythritol triacrylate, trimethylolpropane triacrylate, trimethylolethane triacrylate, dipentaerythritol pentamethacrylate, pentaerythritol hexaacrylate, 1,2 , 4-cyclohexanetetramethacrylate, etc.).

(D) Amides of α, β-unsaturated carboxylic acid: for example, acrylamide, methacrylamide, N-methylacrylamide, N, N-dimethylacrylamide, N-methyl-N-hydroxyethylmethacrylamide, N-tert-butylacrylamide N-tert-octylmethacrylamide, N-cyclohexylacrylamide, N-phenylacrylamide, N- (2-acetoacetoxyethyl) acrylamide, N-acryloylmorpholine, diacetone acrylamide, itaconic acid diamide, N-methylmaleimide, 2 -Acrylamide-methylpropane sulfonic acid, methylene bisacrylamide, dimethacryloyl piperazine and the like.
(E) Unsaturated nitriles: acrylonitrile, methacrylonitrile and the like.
(F) Styrene and its derivatives: styrene, vinyl toluene, p-tertbutyl styrene, vinyl benzoic acid, methyl vinyl benzoate, α-methyl styrene, p-chloromethyl styrene, vinyl naphthalene, p-hydroxymethyl styrene, p- Styrene sulfonic acid sodium salt, p-styrene sulfinic acid potassium salt, p-aminomethylstyrene, 1,4-divinylbenzene and the like.
(G) Vinyl ethers: methyl vinyl ether, butyl vinyl ether, methoxyethyl vinyl ether, and the like.
(H) Vinyl esters: vinyl acetate, vinyl propionate, vinyl benzoate, vinyl salicylate, vinyl chloroacetate, and the like.
(I) α, β-unsaturated carboxylic acid and salts thereof: acrylic acid, methacrylic acid, itaconic acid, maleic acid, sodium acrylate, ammonium methacrylate, potassium itaconate and the like.
(J) Other polymerizable monomers: N-vinylimidazole, 4-vinylpyridine, N-vinylpyrrolidone, 2-vinyloxazoline, 2-isopropenyloxazoline, divinylsulfone, and the like.

  Polymer latex is also commercially available, and the following polymers can be used in combination. Examples of the acrylic polymer include: Sebian A-4635, 4718, 4601 manufactured by Daicel Chemical Industries, Ltd., Nipol Lx811, 814, 821, 820, 855 manufactured by Nippon Zeon Co., Ltd. (P-17: Tg 36 ° C.), 857 × 2 (P-18: Tg43 ° C), Voncoat R3370 (P-19: Tg25 ° C), 4280 (P-20: Tg15 ° C), manufactured by Dainippon Ink & Chemicals, Jurimer ET-410 (manufactured by Nippon Pure Chemical Co., Ltd.) P-21: Tg 44 ° C.), AE116 (P-22: Tg 50 ° C.) manufactured by JSR Corporation, AE119 (P-23: Tg 55 ° C.), AE121 (P-24: Tg 58 ° C.), AE125 (P-25: Tg 60) ° C), AE134 (P-26: Tg48 ° C), AE137 (P-27: Tg48 ° C), AE140 (P-28: Tg53 ° C), AE17 (P-29: Tg 60 ° C.), Aron A-104 (P-30: Tg 45 ° C.) manufactured by Toagosei Co., Ltd., NS-600X, NS-620X manufactured by Takamatsu Yushi Co., Ltd., manufactured by Nissin Chemical Industry Co., Ltd. Vinibrand 2580, 2583, 2641, 2770, 2770H, 2635, 2886, 5202C, 2706, etc. (all are trade names).

  Examples of polyesters include: Finetex EX650, 611, 675, 850 manufactured by Dainippon Ink Chemical Co., Ltd., WD-size, WMS manufactured by Eastman Chemical, A-110, A-115GE manufactured by Takamatsu Yushi Co., Ltd., A- 120, A-121, A-124GP, A-124S, A-160P, A-210, A-215GE, A-510, A-513E, A-515GE, A-520, A-610, A-613, A-615GE, A-620, WAC-10, WAC-15, WAC-17XC, WAC-20, S-110, S-110EA, S-111SL, S-120, S-140, S-140A, S- 250, S-252G, S-250S, S-320, S-680, DNS-63P, NS-122L, NS-122LX, NS-244LX, N -140L, NS-141LX, NS-282LX, Toagosei Co., Ltd. Aron Melt PES-1000 series, PES-2000 series, Toyobo Co., Ltd. Bironal MD-1100, MD-1200, MD-1220, MD-1245, Examples thereof include MD-1250, MD-1335, MD-1400, MD-1480, MD-1500, MD-1930, MD-1985, and Sephorjon ES manufactured by Sumitomo Seika Co., Ltd. (all are trade names).

  Examples of polyurethanes include Dainippon Ink Chemical Co., Ltd. HYDRAN AP10, AP20, AP30, AP40, 101H, Vonic 1320NS, 1610NS, Dainichi Seikatsu Co., Ltd. D-1000, D-2000, D-6000, D-4000, D-9000, NS-155X, NS-310A, NS-310X, NS-311X manufactured by Takamatsu Yushi Co., Ltd., and Elastron manufactured by Daiichi Kogyo Seiyaku Co., Ltd. (all are trade names).

  Examples of rubbers include LACSTAR 7310K, 3307B, 4700H, 7132C (manufactured by Dainippon Ink and Chemicals), Nipol Lx416, LX410, LX430, LX435, LX110, LX415A, LX438C, 2507H, LX303A, LX407BP series, V1004, MH5055 (manufactured by Nippon Zeon Co., Ltd.) and the like (all are trade names).

  Examples of polyolefins include Chemipearl S120, SA100, V300 (P-40: Tg 80 ° C.) manufactured by Mitsui Petrochemical Co., Ltd., Voncoat 2830, 2210, 2960 manufactured by Dainippon Ink Chemical Co., Ltd., Sumitomo Seika Co., Ltd. Examples of Zyxen, Sepoljon G, and copolymer nylons include Sepoljon PA manufactured by Sumitomo Seika Co., Ltd. (all are trade names).

  Examples of the polyvinyl acetates include Nivin Chemical Industry Co., Ltd., Vinibrand 1080, 1082, 1085W, 1108W, 1108S, 1563M, 1566, 1570, 1588C, A22J7-F2, 1128C, 1137, 1138, A20J2, A23J1, A23J1, A23K1, A23P2E, A68J1N, 1086A, 1086D, 1086D, 1108S, 1187, 1241LT, 1580N, 1083, 1571, 1572, 1581, 4465, 4466, 4468W, 4468S, 4470, 4485LL, 4495LL, 1023, 1042, 1060, 1060S, 1080M, 1084W, 1084S, 1096, 1570K, 1050, 1050S, 3290, 1017AD, 1002, 1006, 1008, 1 07L, 1225,1245L, GV-6170, GV-6181,4468W, such as 4468S, and the like (all trade names).

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

  A polymer latex having another structure used in combination with a latex containing monomer units of vinyl chloride used in the present invention has a glass transition temperature (Tg) of −30 ° C. to 70 ° C. in terms of work brittleness and image storage stability. The thing of the range of ° C is preferable, More preferably, it is the range of -10 degreeC-50 degreeC, More 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.

The minimum film-forming temperature (MFT) of the polymer latex is preferably −30 ° C. to 90 ° C., more preferably about 0 ° C. to 70 ° C. A film-forming auxiliary may be added to control the minimum film-forming temperature. 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 Publishing Co. )It is described in. Preferred film-forming aids are the following compounds, but the compounds that can be used in the present invention are 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

  The polymer latex used in the present invention can be easily obtained by a solution polymerization method, a suspension polymerization method, an emulsion polymerization method, a dispersion polymerization method, an anionic polymerization method, a cationic polymerization or the like. 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. Using the mixture and the total amount of monomers, an emulsifier and a polymerization initiator are used, and polymerization is 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.

  The emulsion polymerization method can be generally performed according to the following literature. Tadashi Okuda, Hiroshi Inagaki, “Synthetic Resin Emulsion”, published by Polymer Press (1978), Takaaki Sugimura, Akio Kataoka, Junichi Suzuki, Keiji Kasahara, “Application of Synthetic Latex”, Published by Polymer Press (1993) 1), Soichi Muroi, “Chemistry of Synthetic Latex”, published by Kobunshi Shuppankai (1970). In the emulsion polymerization method for synthesizing the polymer latex used in the present invention, a batch polymerization method, a monomer (continuous / divided) addition method, an emulsion addition method, a seed polymerization method, etc. can be selected from the viewpoint of latex productivity. A batch polymerization method, a monomer (continuous / divided) addition method, and an emulsion addition method are preferred.

  The polymerization initiator only needs to have radical generating ability, such as inorganic peroxides such as persulfate and hydrogen peroxide, peroxides described in Nippon Oil & Fats Co., Ltd. organic peroxide catalog, and Wako Pure Chemical Industries, Ltd. The azo compounds described in the azo polymerization initiator catalog can be used. Among these, water-soluble peroxides such as persulfate and water-soluble azo compounds described in the Wako Pure Chemical Industries, Ltd. Azo Polymerization Initiator Catalog are preferable. Ammonium persulfate, sodium persulfate, potassium persulfate, azobis ( 2-methylpropionamidine) hydrochloride, azobis (2-methyl-N- (2-hydroxyethyl) propionamide), azobiscyanovaleric acid is more preferable, and in particular, peroxidation such as ammonium persulfate, sodium persulfate, potassium persulfate and the like. The product is preferable from the viewpoint of image preservability, solubility, and cost.

  As the addition amount of the polymerization initiator, the polymerization initiator is preferably 0.3% by mass to 2.0% by mass, and 0.4% by mass to 1.75% by mass with respect to the total amount of monomers. Is more preferable, and 0.5% by mass to 1.5% by mass is particularly preferable.

  As the polymerization emulsifier, any of an anionic surfactant, a nonionic surfactant, a cationic surfactant, and an amphoteric surfactant can be used, but the anionic surfactant has dispersibility and image storability. From the viewpoint, it is preferable to use a sulfonic acid type anionic surfactant because polymerization stability can be secured in a small amount and resistance to hydrolysis, and a long chain represented by Perex SS-H (trade name, Kao Corp.). Alkyl diphenyl ether disulfonate is more preferable, and a low electrolyte type such as Pionine A-43-S (trade name, Takemoto Yushi Co., Ltd.) is particularly preferable.

  As the polymerization emulsifier, a sulfonic acid type anionic surfactant is preferably used in an amount of 0.1% by mass to 10.0% by mass with respect to the total amount of monomers, and 0.2% by mass to 7.5% by mass is used. It is more preferable that 0.3% by mass to 5.0% by mass is used.

  In the synthesis of the polymer latex used in the present invention, it is preferable to use a chelating agent. The chelating agent is a compound capable of coordinating (chelating) multivalent ions such as metal ions such as iron ions and alkaline earth metal ions such as calcium ions. Japanese Patent Publication No. 6-8956, US Pat. -73645, JP-A-4-127145, JP-A-4-247703, JP-A-4-305572, JP-A-6-11805, JP-A-5-1773312, JP-A-5-66527, JP-A-5-67527. 158195, JP-A-6-118580, JP-A-6-110168, JP-A-6-161054, JP-A-6-175299, JP-A-6-214352, JP-A-7-114161, JP-A-7-114154 JP-A-7-120894, JP-A-7-199433, JP-A-7-306504, JP-A-9-43792 May JP 8-314090, JP-A-10-182571, JP-A-10-182570, can be used the compounds described in JP or the specification of JP-A-11-190892.

  Examples of the chelating agent include inorganic chelate compounds (sodium tripolyphosphate, sodium hexametaphosphate, sodium tetrapolyphosphate, etc.), aminopolycarboxylic acid chelate compounds (nitrilotritriacetic acid, ethylenediaminetetraacetic acid, etc.), organic phosphonic acid chelate compounds ( Research Disclosure 18170, JP-A-52-102726, 53-42730, 56-97347, 54-121127, 55-4024, 55-4025, 55-29883, 55 -126241, 55-65955, 55-65956, 57-17943, 54-61125 and West German Patent No. 1045373, or the like), a polyphenol chelating agent Preferably such polyamine chelating compounds, with aminopolycarboxylic acid derivatives being particularly preferred.

  Preferable examples of the aminopolycarboxylic acid derivatives include the compounds listed in the appendix of “EDTA (-Complexane Chemistry)” (Nanedo, 1977), and some of the carboxyl groups of these compounds are sodium or potassium. Alkali metal salts and ammonium salts such as may be substituted. Particularly preferred aminocarboxylic acid derivatives include iminodiacetic acid, N-methyliminodiacetic acid, N- (2-aminoethyl) iminodiacetic acid, N- (carbamoylmethyl) iminodiacetic acid, nitrilotriacetic acid, ethylenediamine-N, N '-Diacetic acid, ethylenediamine-N, N'-di-α-propionic acid, ethylenediamine-N, N'-di-β-propionic acid, N, N'-ethylene-bis (α-o-hydroxyphenyl) glycine N, N′-di (2-hydroxybenzyl) ethylenediamine-N, N′-diacetic acid, ethylenediamine-N, N′-diacetic acid-N, N′-diacethydroxamic acid, N-hydroxyethylethylenediamine-N , N ′, N′-triacetic acid, ethylenediamine-N, N, N ′, N′-tetraacetic acid, 1,2-propylenediamine-N, N, N ′ N′-tetraacetic acid, d, l-2,3-diaminobutane-N, N, N ′, N′-tetraacetic acid, meso-2,3-diaminobutane-N, N, N ′, N′-four Acetic acid, 1-phenylethylenediamine-N, N, N ′, N′-tetraacetic acid, d, l-1,2-diphenylethylenediamine-N, N, N ′, N′-tetraacetic acid, 1,4-diaminobutane -N, N, N ', N'-tetraacetic acid, trans-cyclobutane-1,2-diamine-N, N, N', N'-tetraacetic acid, trans-cyclopentane-1,2-diamine-N, N, N ′, N′-tetraacetic acid, trans-cyclohexane-1,2-diamine-N, N, N ′, N′-tetraacetic acid, cis-cyclohexane-1,2-diamine-N, N, N ′ , N′-tetraacetic acid, cyclohexane-1,3-diamine-N, N, N ′, N′-four Acid, cyclohexane-1,4-diamine-N, N, N ′, N′-tetraacetic acid, o-phenylenediamine-N, N, N ′, N′-tetraacetic acid, cis-1,4-diaminobutene- N, N, N ′, N′-tetraacetic acid, trans-1,4-diaminobutene-N, N, N ′, N′-tetraacetic acid, α, α′-diamino-o-xylene-N, N, N ′, N′-tetraacetic acid, 2-hydroxy-1,3-propanediamine-N, N, N ′, N′-tetraacetic acid, 2,2′-oxy-bis (ethyliminodiacetic acid), 2,2 '-Ethylenedioxy-bis (ethyliminodiacetic acid), ethylenediamine-N, N'-diacetic acid-N, N'-di-α-propionic acid, ethylenediamine-N, N'-diacetic acid-N, N'- Di-β-propionic acid, ethylenediamine-N, N, N ′, N′-tetrapropionic acid Diethylenetriamine-N, N, N ′, N ″, N ″ -pentaacetic acid, triethylenetetramine-N, N, N ′, N ″, N ′ ″, N ′ ″-hexaacetic acid, 1, 2,3-triaminopropane-N, N, N ′, N ″, N ′ ″, N ′ ″-hexaacetic acid, and some of the carboxyl groups of these compounds are sodium or potassium Substituted ones such as alkali metal salts and ammonium salts can also be mentioned.

  The addition amount of the chelating agent is preferably 0.01% by mass to 0.4% by mass, more preferably 0.02% by mass to 0.3% by mass with respect to the total amount of monomers. It is especially preferable that it is 03 mass%-0.15 mass%. When the amount of the chelating agent is less than 0.01% by mass, capture of metal ions mixed in the production process of the polymer latex becomes insufficient, stability against aggregation of the latex is lowered, and applicability is deteriorated. On the other hand, if it exceeds 0.4%, the viscosity of the latex increases and the coatability is lowered.

  A chain transfer agent is preferably used for the synthesis of the polymer latex used in the present invention. As the chain transfer agent, those described in “Polymer Handbook, 3rd edition” (Wiley-Interscience, 1989) are preferable. Sulfur compounds are more preferred because they have high chain transfer ability and can be used in small amounts. Hydrophobic mercaptan-based chain transfer agents such as tert-dodecyl mercaptan and n-dodecyl mercaptan are particularly preferred.

  The amount of the chain transfer agent is preferably 0.2% by mass to 2.0% by mass, more preferably 0.3% by mass to 1.8% by mass, and 0.4% by mass to 1.6% by mass with respect to the total amount of monomers. Mass% is particularly preferred.

  In emulsion polymerization, in addition to the above compounds, electrolytes, stabilizers, thickeners, antifoaming agents, antioxidants, vulcanizing agents, antifreezing agents, gelling agents, vulcanization accelerators, etc. are described in synthetic rubber handbooks, etc. These additives may be used.

The polymer latex used in the present invention is preferably prepared 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, oxyethyl phenyl ether A water miscible organic solvent such as can be used.
In addition, the polymer latex in the image-receiving sheet used in the present invention includes a gel or a dried film formed by drying a part of the solvent after coating.

<Water-soluble polymer>
The receiving layer preferably contains 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. The water-soluble polymer in the present invention does not include the polymer latex.
In the present invention, a water-soluble polymer may be labeled as a binder to distinguish it from the polymer latex.

Of the water-soluble polymers that can be used in the present invention, natural polymers and semi-synthetic polymers will be described in detail. Examples of plant polysaccharides include gum arabic, κ-carrageenan, ι-carrageenan, λ-carrageenan, guar gum (such as Supercol manufactured by Squalon), locust bean gum, pectin, tragacanth, and corn starch (Purity- manufactured by National Starch & Chemical Co.). 21), phosphorylated starch (National Star & Chemical Co., National 78-1898, etc.), and other microbial polysaccharides such as xanthan gum (Kelco, Keltrol T), dextrin (National Star & Chemical Co., Nadex 360, etc.) ) And other animal-based natural polymers such as gelatin (Crodine B419 from Croda), casein Such as sodium chondroitin sulfate (such as Croda made Cromoist CS), and the like (all trade names). Cellulose-based materials include ethyl cellulose (ICF Cellofas WLD, etc.), carboxymethyl cellulose (Daicel CMC, etc.), hydroxyethyl cellulose (Daicel HEC, etc.), hydroxypropyl cellulose (Aqualon Klucel, etc.), and methyl cellulose (Henkel). Viscontran, etc.), nitrocellulose (Isopropyl Wet, etc. from Hercules), cationized cellulose (Crodacel QM, etc. from Croda), etc. (all are trade names). As starch systems, phosphorylated starch (such as National Star &Chemical's National 78-1898), alginic acid systems such as sodium alginate (such as Kelco's Keltone), propylene glycol alginate, and other classifications include cationized guar gum (Alcolac). Hi-care 1000, etc.) and sodium hyaluronate (Hyalure, etc. from Lifecare Biomedical) (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 mass%, saponification degree 88. 0 ± 1.5 mol%, sodium acetate content 1.0 mass%, volatile matter 5.0 mass%, viscosity (4 mass%, 20 ° C.) 44.0 ± 4.0 CPS], PVA-228 [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.) 65.0 ± 5.0 CPS], PVA-235 [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.) 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 mass%, volatile matter 5.0 mass%, viscosity (4 mass%, 20 ° C.) 23.0 ± 3.0 CPS], PVA-217E [PVA content 94.0% by mass, saponification degree 88.0 ± 1.0 mol%, Sodium acid content 1.0% by mass, volatile matter 5.0% by mass, viscosity (4% by mass, 20 ° C.) 23.0 ± 3.0CPS], PVA-220E [PVA content 94.0% by mass, saponification Degree 88.0 ± 1.0 mol%, sodium acetate content 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 mass%, saponification degree 79. 5 ± 1.5 mol%, sodium acetate content 1.0 mass%, volatile content 5.0 mass%], VA-613 [PVA content 94.0% by mass, saponification degree 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), volatilization 3.0% by mass, viscosity (4% by mass, 20 ° C.) 5.4 ± 0.4 CPS] (all are trade names manufactured by Kuraray Co., Ltd.) and the like.

  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 Publications published 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 are transparent or translucent and are generally colorless and are natural resins, polymers and copolymers, synthetic resins, polymers and copolymers, and other film-forming media such as rubbers, polyvinyl alcohols, hydroxyethyl celluloses, cellulose Acetates, cellulose acetate butyrate, polyvinylpyrrolidone, starch, polyacrylic acid, polymethylmethacrylic acid, polyvinyl chloride, polymethacrylic acid, 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 addition amount of the water-soluble polymer in the receiving layer is preferably 1 to 25% by mass, and more preferably 1 to 10% by mass with respect to the entire receiving layer.

<Hardener>
The hardening agent used in the present invention as a crosslinking agent can be added to a coating layer (for example, a receiving layer, a heat insulating layer, a subbing layer, etc.) of the image receiving sheet.
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) on page 8, lower right of JP-A-2-214852, 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 Nos. 59-116655, 62-245261, and 61-18842. 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 ) nL
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 preferably, the chlorine atom is substituted at the 2nd, 4th or 6th position by 2 or 3 groups. 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 chlorotriazine hardeners 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.

<Emulsions>
The receiving layer of the heat-sensitive transfer image-receiving sheet used in the present invention preferably contains an emulsion. The emulsion preferably used in the present invention will be described below.
Hydrophobic additives such as lubricants and antioxidants can be obtained by a known method such as the method described in US Pat. No. 2,322,027, such as a layer of an image receiving sheet (for example, a receiving layer, a heat insulating layer, an undercoat layer, etc.). ) Can be introduced in. In this case, U.S. Pat. Nos. 4,555,470, 4,536,466, 4,536,467, 4,587,206, 4,555,476 No. 4,599,296, JP-B-3-62256, or a high boiling point organic solvent described in the specification or the like, if necessary, in combination with a low boiling point organic solvent having a boiling point of 50 ° C. to 160 ° C. Can be used. These lubricants, antioxidants, high-boiling organic solvents and the like can be used in combination of two or more.

  As the antioxidant (hereinafter also referred to as a radical scavenger), a compound represented by any one of the following general formulas (E-1) to (E-3) is preferably used.

R ₄₁ is an aliphatic group, aryl group, heterocyclic group, acyl group, aliphatic oxycarbonyl group, aryloxycarbonyl group, aliphatic sulfonyl group, arylsulfonyl group, phosphoryl group, or —Si (R ₄₇ ) (R ₄₈ ). (R ₄₉ ) is represented. Here, R ₄₇ , R ₄₈ and R ₄₉ each independently represents an aliphatic group, an aryl group, an aliphatic oxy group or an aryloxy group. R ₄₂ , R ₄₃ , R ₄₅ and R ₄₆ represent a hydrogen atom or a substituent. Examples of the substituent include halogen atoms, aliphatic groups (including alkyl groups, alkenyl groups, alkynyl groups, cycloalkyl groups, and cycloalkenyl groups), aryl groups, heterocyclic groups, hydroxy groups, mercapto groups, aliphatic oxy groups. Group, aryloxy group, heterocyclic oxy group, aliphatic thio group, arylthio group, heterocyclic thio group, amino group, aliphatic amino group, arylamino group, heterocyclic amino group, acylamino group, sulfonamide group, cyano group Nitro group, carbamoyl group, sulfamoyl group, acyl group, aliphatic oxycarbonyl group, aryloxycarbonyl group and the like. R _{a1 to} R _a4 each independently represents a hydrogen atom or an aliphatic group (for example, methyl, ethyl).
With respect to the compound represented by any one of the general formulas (E-1) to (E-3), preferred substituents in terms of the effects of the present invention will be described.
In the general formulas (E-1) to (E-3), R ₄₁ is an aliphatic group, an acyl group, an aliphatic oxycarbonyl group, an aryloxycarbonyl group, or a phosphoryl group, and R ₄₂ , R ₄₃ , R ₄₅ And R ₄₆ are each independently preferably a hydrogen atom, an aliphatic group, an aliphatic oxy group or an acylamino group, R ₄₁ is an aliphatic group, and R ₄₂ , R ₄₃ , R ₄₅ and R ₄₆ are It is more preferable that each independently represents a hydrogen atom or an aliphatic group.
Although the preferable specific example represented by either of general formula (E-1)-(E-3) below is shown below, this invention is not limited to these.

  The content of the antioxidant is preferably 1.0 to 7.0% by mass, more preferably 2.5 to 5.0% by mass, based on the solid content in the polymer latex.

  Examples of the lubricant include solid waxes such as polyethylene wax, amide wax, and Teflon (registered trademark) powder; silicone oil, phosphate ester compounds, fluorine surfactants, silicone surfactants, and other in the technical field. A known release agent can be used, and a fluorine-based compound represented by a fluorine-based surfactant, a silicone-based surfactant, a silicone oil such as a silicone oil and / or a cured product thereof is preferably used. The content of the lubricant is preferably 1.0 to 10.0% by mass, more preferably 1.5 to 2.5% by mass, based on the solid content in the polymer latex.

  As the silicone oil as the lubricant, straight silicone oil, modified silicone oil and its cured product can be used. Straight silicone oils include dimethyl silicone oil, methylphenyl silicone oil, and methylhydrogen 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.) and the like, 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 receiving layer. The release agent is 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 oils (24-510, KF41-410, both trade names, Shin-Etsu Chemical ( Etc.). 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, an aryl group, or a linear or branched alkyl group that may be substituted with a cycloalkyl group. m and n represent an integer of 2000 or less, and a and b represent an integer of 30 or less.

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

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

  Silicone oils such as those described above are described in “Silicone Handbook” (published by Nikkan Kogyo Shimbun Co., Ltd.). The technique can be preferably used.

High boiling point organic 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 塁 (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, etc.), chlorinated paraffins, hydrocarbons (dode) Rubenzen, diisopropyl naphthalene), carboxylic acids (2- (2,4-di -tert- amylphenoxy) butyric acid, and the like.
The following compounds are preferably used.

  Further, an organic solvent (such as ethyl acetate, butyl acetate, methyl ethyl ketone, cyclohexanone, or methyl cellosolve acetate) having a boiling point of 30 ° C. or higher and 160 ° C. or lower may be used in combination as an auxiliary solvent. The amount of the high-boiling organic solvent is 10 g or less, preferably 5 g or less, more preferably 1 g to 0.1 g based on 1 g of the hydrophobic additive used. In addition, 1 milliliter or less, further 0.5 milliliter or less, particularly 0.3 milliliter or less is appropriate for 1 g of binder.

A dispersion method using a polymer described in JP-B-51-39853 and JP-A-51-59943, or a fine particle dispersion described in JP-A-62-22422, etc. Can also be used. In the case of a compound that is substantially insoluble in water, it can be dispersed and contained as fine particles in a binder other than the above method.
In dispersing the hydrophobic compound in the hydrophilic colloid, various surfactants can be used. For example, the surfactants described in JP-A No. 59-157636, pages 37 to 38 can be used. Also, phosphate ester type surfactants described in JP-A-7-56267, JP-A-7-228589 and West German Patent No. 1,932,299A can be used.

<Ultraviolet absorber>
In the present invention, an ultraviolet absorber may be added to the receiving layer in order to improve light resistance. At this time, the UV absorber can be fixed to the receiving layer by increasing the molecular weight, and can be prevented from being diffused into the ink sheet or sublimation / transpiration due to heating.
As the ultraviolet absorber, compounds having various ultraviolet absorber skeletons widely known in the field of information recording can be used. Specific examples include 2-hydroxybenzotriazole type ultraviolet absorbers, 2-hydroxybenzotriazine type ultraviolet absorbers, and compounds having a 2-hydroxybenzophenone type ultraviolet absorber skeleton. A compound having a benzotriazole type or triazine skeleton is preferable from the viewpoint of ultraviolet absorption ability (absorption coefficient) / stability, and a compound having a benzotriazole type or benzophenone type skeleton is preferable from the viewpoint of increasing the molecular weight or forming a latex. Specifically, an ultraviolet absorber described in JP 2004-361936 A can be used.

  The ultraviolet absorber preferably has absorption in the ultraviolet region and does not have an absorption edge in the visible region. Specifically, when added to the receiving layer to form a thermal transfer image-receiving sheet, the reflection density at 370 nm is preferably Abs 0.5 or more, and the reflection density at 380 nm is more preferably Abs 0.5 or more. . The reflection density at 400 nm is preferably Abs 0.1 or less. A high reflection density in the range exceeding 400 nm is not preferable because the image is yellowed.

  In the present invention, the ultraviolet absorber has a high molecular weight, preferably a weight average molecular weight of 10,000 or more, and more preferably a weight average molecular weight of 100,000 or more. As a means for increasing the molecular weight, it is preferable to graft an ultraviolet absorber onto the polymer. The polymer that becomes the main chain preferably has a polymer skeleton that is inferior in dyeability to the dye used in combination. Moreover, it is preferable to have sufficient film strength when the film is formed. The graft ratio of the ultraviolet absorber to the polymer main chain is preferably 5 to 20% by mass, and more preferably 8 to 15% by mass.

Moreover, it is more preferable that the polymer grafted with the ultraviolet absorber is made into a latex. The receptor layer can be formed by forming an aqueous dispersion type coating solution into a latex to form a latex, and the manufacturing cost can be reduced. For example, the method described in Japanese Patent No. 3450339 can be used as a method for forming a latex. Examples of the latex-made ultraviolet absorber include ULS-700, ULS-1700, ULS-1383MA, ULS-1635MH, XL-7016, ULS-933LP, ULS-935LH, Shin-Nakamura Chemical Co., Ltd. Commercially available ultraviolet absorbers such as New Coat UVA-1025W, New Coat UVA-204W, and New Coat UVA-4512M (both are trade names) can also be used.
When the polymer to which the ultraviolet absorber is grafted is made into a latex, it is possible to form a receiving layer in which the ultraviolet absorber is uniformly dispersed by mixing with the latex of the above-mentioned dyeable receiving polymer and applying it.

  The added amount of the polymer grafted with the ultraviolet absorber or the latex thereof is preferably 5 to 50 parts by mass, more preferably 10 to 30 parts by mass with respect to the dyeable accepting polymer latex forming the receptor layer.

<Release agent>
In addition, a release agent may be added to the receiving layer in order to prevent thermal fusion with the thermal transfer sheet during image formation. As the mold release agent, silicone oil, phosphate ester plasticizer fluorine compound, and various wax dispersions can be used. In particular, silicone oil and wax dispersion are preferably used.

  As the silicone oil, modified silicone oils such as epoxy modification, alkyl modification, amino modification, carboxyl modification, alcohol modification, fluorine modification, alkylaralkyl polyether modification, epoxy / polyether modification, and polyether modification are preferably used. A reaction product of vinyl-modified silicone oil and hydrogen-modified silicone oil is preferable. The addition amount of the release agent is preferably 0.2 to 30 parts by mass with respect to the receiving polymer.

A known dispersion can be used as the wax dispersion. In the present invention, “wax is treated as an organic substance having a solid or semi-solid alkyl chain at normal temperature” (according to the definition of “Revised properties and application of wax” (Shoshobo, 1989)). Examples of preferred compounds include candelilla wax, carnauba wax, rice wax, wood wax, montan wax, ozokerite, paraffin wax, microcrystalline wax, petrolactam, Fischer-Tropsch wax, polyethylene wax, montan wax derivatives, paraffin wax. Derivatives, microcrystalline wax derivatives, hardened castor oil, hardened castor oil derivatives, 12-hydroxystearic acid, stearamide, phthalic anhydride, chlorinated hydrocarbons, and other blended waxes. Of these, carnauba wax, montan wax and derivatives thereof, paraffin wax and derivatives thereof, microcrystalline wax and derivatives thereof, polyethylene wax and stearamide are preferable, and kaunauba wax, mondan wax and derivatives thereof, microcrystalline wax. Stearamide is more preferable, and montan wax and derivatives thereof, and microcrystalline wax are more preferable.
This wax is selected from those having a melting point of 25 ° C to 120 ° C, preferably 40 ° C to 100 ° C, more preferably 60 ° C to 90 ° C.
The wax is preferably an aqueous dispersion, and more preferably finely divided. The water dispersion method and the micronization method can be achieved by the methods described in “Revised Wax Properties and Applications” (Sachibo, 1989).
The addition amount of the wax is preferably 0.5% by mass to 30% by mass, more preferably 1% by mass to 20% by mass, and still more preferably 1.5% by mass to 15% by mass of the total solid content of the receiving layer. .

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), and more preferably 1 to 1. 8 g / m ^2, more preferably the coating weight of 2~7g / m ² is preferred. The thickness of the receiving layer is preferably 1 to 20 μm.

(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.

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 resin , 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 are added to polyvinylidene chloride, poly It is covered with a resin made of acrylonitrile, polyacrylic acid, polyacrylic acid ester, or a mixture or polymer thereof. After coating, the low-boiling liquid inside the particles expands by heating, and the interior becomes hollow. Examples include foamed microballoons, [3] microballoons obtained by heating and foaming the above [2] in advance to form hollow polymers, and the like. That.
In the present invention, the non-foamed hollow polymer latex formed of the polystyrene resin, acrylic resin or styrene-acrylic resin of the above [1] is used.

Preferably 0.1~20μm particle size of the hollow polymer, more preferably 0.1-2 .mu.m, more preferably 0.1 to 1 [mu] m, 0.2 to 0.8 [mu] m is rather particular preferred, in the present invention Use those having a particle size of 0.1 to 2 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. 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. It is not preferable to include a resin (dye dyeing resin) that is not resistant to an organic solvent in the heat insulating layer because blurring of an image after image transfer increases. 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”.

Moreover, in this invention, although a heat insulation layer contains a water-soluble polymer or polymer latex, it is preferable to contain the said water-soluble polymer. The compounds that can be preferably used are the same as described above.
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.

The heat insulating layer preferably contains gelatin. The amount of the heat insulating layer in the gelatin coating solution is preferably 0.5 to 14% by mass, 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 by a crosslinking agent. The preferred range of the crosslinking agent that can be preferably used and the amount of use thereof is the same as described above.
Although the water-soluble polymer in the heat insulating layer varies depending on the type of the crosslinking agent, it is preferably 0.1 to 20% by mass crosslinked with respect to the water-soluble polymer, and 1 to 10% by mass crosslinked. Is more preferable.

  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.
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.

(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, a support having a structure in which a polyolefin resin layer is provided on both sides of a base paper or at least a side provided with a receiving layer is used. Such a support has water resistance. 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 of the present invention, for example, coated paper or laminated paper in which a polyolefin resin layer is coated on both sides of the base paper or at least the side on which the receiving layer is provided can be used.

In the present invention, a support having a structure in which a polyolefin resin layer is provided on both sides of a base paper or at least a side provided with a receiving layer is used. There is no restriction | limiting in particular as a raw material of a base paper, According to the objective, it can select. For example, high-quality paper, paper described in pages 223 to 240 of Corona Publishing Co., Ltd. (Showa 54), “Basics of photographic optics, silver halide photography” edited by the Japan Photographic Society can be used.
The raw material of the base paper is not particularly limited, and examples thereof include natural pulp selected from conifers and hardwoods, synthetic pulps made of plastic materials such as polyethylene and polypropylene, or a mixture of synthetic pulp and natural pulp.
The pulp that can be used as the raw material of the base paper is a hardwood bleached kraft pulp (LBKP) from the viewpoint of improving the surface smoothness, rigidity and dimensional stability (curlability) of the base paper to a balanced and sufficient level at the same time. It is preferable to use softwood bleached kraft pulp (NBKP) or hardwood sulfite pulp (LBSP). It is appropriate to use mainly hardwood pulp having a short fiber length as the main pulp fiber. A beater or refiner can be used to beat the pulp. Various additives (for example, fillers, dry paper strength enhancers, sizing agents, wet paper strength enhancers, fixing agents, pH adjusters, other chemicals, etc.) are added to the pulp slurry obtained after pulp beating. it can. Examples of these are described in paragraph numbers 0021 to 0025 of JP-A-2004-271790.
Density of the base paper is preferably 0.8 g / m ³ or more 1.2 g / m ³ or ^{less, 0.9g / m 3 ~1.1g / m} 3 is rather more preferable, in the present invention, 0.9 g / m ³ is a ~1.1g / m ^3. Although base paper thickness can be appropriately selected depending on the purpose, a 50~300μm in the present invention, 100-200 [mu] m is favorable preferable.
The basis weight of base paper is not particularly limited and may be selected according to the purpose, for example, preferably ^{50~300g / m 2, 100~200g / m} 2 is particularly preferred.

  For the polyolefin resin layer, for example, a polyolefin resin such as a homopolymer of α-olefin such as polyethylene and polypropylene and a mixture thereof is used. These polyolefin resins are not particularly limited in molecular weight as long as extrusion coating is possible, and can be selected according to the purpose. In the present invention, a polyolefin having a molecular weight in the range of 20,000 to 200,000 is preferred. In the present invention, the resins and additives described in paragraph numbers 0031 to 0048 of JP-A-2004-271790 can be used depending on the purpose.

  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.

<Coated paper>
When the support of the present invention is a coated paper, it is a paper in which a polyolefin resin is coated on a surface of a base paper or the like on both surfaces of the base paper or at least a surface provided with a receiving layer. The amount of work is different. The coating amount of the polyolefin resin layer is preferably 5 g / m ² or more and 70 g / m ² or less. Examples of such coated paper include art paper, cast coated paper, Yankee paper, and the like.

As the polyolefin resin to be coated on the base paper or the like, it is appropriate to use a thermoplastic resin. Examples of such a thermoplastic resin include polyolefin resins such as a polyethylene resin and a polypropylene resin.
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).

  In addition, said polyolefin resin may be used individually by 1 type, and may use 2 or more types together.

  In addition, the polyolefin resin can contain pigments and dyes such as brighteners, conductive agents, fillers, titanium oxide, ultramarine, and carbon black as required.

<Laminated paper>
When the support of the present invention is a laminated paper, it is a paper obtained by laminating a polyolefin resin on a sheet such as a base paper. Polyolefin resin may be used individually by 1 type, and may use 2 or more types together.

  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 the thermoplastic resin layers are formed 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 the 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 an extrudability. In the present invention, a polyolefin having a molecular weight in the range of 20,000 to 200,000 is preferable. In the present invention, the resins and additives described in paragraph No. 0031 on page 9 to paragraph No. 0048 on page 11 of JP-A No. 2004-271790 can be used depending on the purpose.
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 of the present invention, a 100μm~350μm, 150μm~260μm virtuous preferable. 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.

It is preferable that the center line average roughness (Ra) on the surface of the support on which the receiving layer is provided is 0.5 μm or less. More preferably, the center line average roughness (Ra) of the surface of the support on the side of the support used in the present invention is 0.4 μm or less. The center line average roughness (Ra) on the side of the support on which the back layer is provided is preferably 0.75 μm to 10 μm, and in addition to this, the local summit average interval (S) is more preferably 30 μm to 75 μm. .
The center line average roughness Ra of the support surface represents the state of irregularities on the support surface.
When Ra is larger than 0.5 μm, the occurrence of image unevenness during thermal transfer recording increases. In the support of the present invention, the method for measuring the center line average roughness Ra of the surface is as follows.
Two-dimensional roughness measurement is performed with a center line average roughness Ra stylus type roughness meter (for example, sufcom 575, manufactured by Tokyo Seimitsu Co., Ltd.), and the average roughness specified in ISO 4287 is measured five times. The average value is the center line average roughness. The conditions for the two-dimensional roughness measurement are shown below.
Cut-off value 0.8 mm, tilt correction FLAT-ML, measurement length 3 mm, vertical magnification 10000 times, scanning speed 0.3 mm / sec, stylus tip diameter 2 μm.

(Curl adjustment layer)
If the support of the present invention is exposed as it is, the thermal 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 adjustment 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, it can be formed in the same manner as that described in, for example, 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, JP-A Nos. 2,761,791, 2,681,234, 3,508,947, 4,457,256, 3,993,019, Kaisho 63-54975, JP-A-61-278848, 55-86557, 52-31727, 55-142565, 50-43140, 63-80872, 54-54020 JP-A-5-104061, JP-A-5-127305, JP-B49-7050, or the specification of Edgar B. et al. The so-called slide coating method (slide coating method) and curtain coating method (curtain coating method) described in Guoff et al., “Coating and Drying Defects: Troubleshooting Operating Problems”, John Wiley & Sons, 1995, p. Are known.
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 lower limit is preferably 0.001 μm. 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 quickly solidify. 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.

The thermal transfer sheet (ink sheet) used in combination with the above-described thermal transfer image-receiving sheet of the present invention at the time of thermal transfer image formation is provided with a dye layer containing a diffusion transfer dye on a support. Ink sheets can be used. 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
The present invention can be used in printers, copiers and the like using a thermal transfer recording system.

  The features of the present invention will be described more specifically with reference to the following examples. The materials, amounts used, ratios, processing details, processing procedures, and the like shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the specific examples shown below. In Examples, “part” or “%” is based on mass unless otherwise specified.

Example 1
(Preparation of ink sheet)
A polyester film (Lumirror, trade name, manufactured by Toray Industries, Inc.) having a thickness of 4.5 μm was used as a base film. The following adhesive layer (coating amount 0.07 g / m ² at the time of dry film) was formed on the surface side, and yellow, magenta, and cyan compositions having the following composition were applied to each color (coating amount 0. 8 g / m ² ).

<Adhesive layer composition>
Polyvinylpyrrolidone resin (K-90, trade name, manufactured by ISP) 5 parts by mass Methyl ethyl ketone 47.5 parts by mass Isopropyl alcohol 47.5 parts by mass

<Dye layer composition liquid>
Yellow ink Dye (7) -1 2.5 parts by weight Dye (8) -1 2.0 parts by weight Polyester 1 4.5 parts by weight Methyl ethyl ketone / toluene (mass ratio 1/1) 90 parts by weight Magenta ink Dye (9) -1 1.0 part by weight Dye (10) -1 1.0 part by weight Dye (11) -1 2.5 parts by weight Polyester 1 4.5 parts by weight Methyl ethyl ketone / toluene (mass ratio 1/1) 90 parts by weight cyan Ink Dye (12) -1 2.5 parts by mass Dye (13) -1 2.5 parts by mass Polyester 1 4.5 parts by mass Methyl ethyl ketone / toluene (mass ratio 1/1) 90 parts by mass

Said polyester 1 is the following.
Polyester 1
A polyester having a number average molecular weight of 2000 obtained by polymerizing the following acid component and diol component in the following molar ratio.
Isophthalic acid 5
Terephthalic acid 45
Ethylene glycol 5
Diethylene glycol 45

Further, a heat-resistant active layer (a coating amount at the time of dry film 1 g / m ² ) was formed on the back side of the film to prepare an ink sheet.
<Heat resistant slipping layer composition>
13.6 parts by mass of polyvinyl butyral resin (ESREC BX-1, trade name, manufactured by Sekisui Chemical Co., Ltd.)
0.6 parts by mass of polyisocyanate curing agent (Takenate D218, trade name, manufactured by Takeda Pharmaceutical Company Limited)
0.8 parts by mass of phosphate ester (Pricesurf A208S, trade name, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.)
Methyl ethyl ketone 42.5 parts by mass Toluene 42.5 parts by mass

Production of image-receiving sheets 101 to 114 (production of support)
50 parts by mass of LBKP (hardwood bleached kraft pulp) made of acacia and 50 parts by mass of LBKP made of aspen were each beaten to 300 ml of Canadian freeness by a disc refiner to prepare a pulp slurry.
Next, to the pulp slurry obtained above, cation-modified starch (manufactured by NSC Japan, trade name, CAT0304L) 1.3% per pulp, anionic polyacrylamide (manufactured by Seiko PMC Co., trade name) DA4104) 0.15%, alkyl ketene dimer (Arakawa Chemical Co., Ltd., trade name, size pine K) 29%, epoxidized behenamide 0.29%, polyamide polyamine epichlorohydrin (Arakawa Chemical Co., Ltd., trade name, Arafix 100) 0.32% was added, followed by 0.12% defoamer .

In the process of making the pulp slurry prepared as described above with a long paper machine and pressing the felt surface of the web against the drum dryer cylinder through the dryer canvas for drying, the tensile force of the dryer canvas is 1.6 kg / After setting to cm and drying, a size press applies 1 g / m ² of polyvinyl alcohol (trade name, KL-118, manufactured by Kuraray Co., Ltd.) on both sides of the base paper and performs calendar treatment. It was. The basis weight and thickness of the base paper produced were those shown in Table 1 below.

After performing corona discharge treatment on the wire surface (back surface) side of the obtained base paper, MFR (melt flow rate; hereinafter the same) 16.0 g / 10 min, density 0.96 g / cm using a melt extruder. ³ high density polyethylene (hydrotalcite (trade name: DHT-4A, manufactured by Kyowa Chemical Industry Co., Ltd.) 250 ppm, secondary antioxidant (tris (2,4-di-t-butylphenyl) phosphite, Trade name: Irgafos 168, manufactured by Ciba Specialty Chemicals Co., Ltd., containing 200 ppm), MFR 4.0 g / 10 min, low density polyethylene having a density of 0.93 g / cm ³ , 75/25 (mass ratio) ) Was coated so that the thickness was as shown in Table 1 to form a thermoplastic resin layer comprising a mat surface (hereinafter, this thermoplastic resin layer surface is referred to as “back surface”). This thermoplastic resin layer on the back side is further subjected to corona discharge treatment, and then, as an antistatic agent, aluminum oxide (manufactured by Nissan Chemical Industries, Ltd., trade name, aluminazil 100) and silicon dioxide (Nissan Chemical). A dispersion obtained by dispersing in water at a mass ratio of 1: 2 manufactured by Kogyo Co., Ltd., trade name, Snowtex O) was applied so that the dry mass was 0.2 g / m ² . MFR 4.0 g / 10 min corona-treated and having a titanium oxide content of 10% by weight, low density polyethylene having a density of 0.93 g / m ² was coated using a melt extruder so as to have an amount shown in Table 1 below. A thermoplastic resin layer comprising a mirror surface was formed.

With respect to the obtained supports 101 to 114, the center line average roughness Ra was measured as follows. The results are shown in Table 1 below. Two-dimensional roughness measurement is performed with a center line average roughness Ra stylus type roughness meter (SUFCOM 575, trade name, manufactured by Tokyo Seimitsu Co., Ltd.), and the average roughness specified in ISO 4287 is measured five times. The average value was defined as the center line average roughness Ra.
The conditions for the two-dimensional roughness measurement were a cut-off value of 0.8 mm, an inclination correction FLAT-ML, a measurement length of 3 mm, a vertical magnification of 10,000 times, a scanning speed of 0.3 mm / sec, and a stylus tip diameter of 2 μm.

(Emulsion creation)
Emulsified dispersion A was prepared by the following procedure. Antioxidant (EB-9) was dissolved in 42 g of a high boiling point solvent (Solv-5) and 20 ml of ethyl acetate, and this liquid was stirred and emulsified in 250 g of a 20% by weight gelatin aqueous solution containing 1 g of sodium dodecylbenzenesulfonate. (Dissolver) was emulsified and dispersed, and water was added to prepare 380 g of Emulsion A.
The amount of antioxidant (EB-9) added was 30 mmol in Emulsion A.

  On the supports 101 to 114 prepared as described above, a multi-layer coating composition having a configuration of an undercoat layer, a heat insulating layer, and a receiving layer was formed in order from the lower layer. These are image receiving sheets 101-114. The composition and coating amount of the coating solution are shown below.

Undercoat layer coating liquid (composition)
93 parts by mass of styrene-butadiene latex (manufactured by Nippon A & L Co., Ltd., trade name, SR103)
Polyvinyl alcohol (PVA) 8.7% aqueous solution 57 parts by mass Adjusting pH to 7.5 with NaOH (application amount) 21 ml / m ²

Heat insulation layer coating liquid (composition)
Hollow polymer latex 38 parts by mass (manufactured by Nippon Zeon Co., Ltd., trade name, MH5055)
16% gelatin aqueous solution 26 parts by weight Water 4 parts by weight Adjust pH to 7.8 with NaOH (coating amount) 42 ml / m ²

Receiving layer coating solution (composition)
53 parts by mass of vinyl chloride polymer latex (manufactured by Nissin Chemical Co., Ltd., trade name, VINYBRAN 609)
Emulsion A prepared earlier 13 parts by weight Microcrystalline wax 7 parts by weight (EMUSTAR-042X, trade name, Nippon Seiwa Co., Ltd.)
Water 35 parts by weight Adjusting pH to 7.4 with NaOH (application amount) 18 ml / m ²

  The following compound A (crosslinking agent) was added to the receiving layer coating solution immediately before coating. The amount of Compound A added was 3% by mass relative to the total mass of gelatin in the heat insulating layer and the receiving layer.

(Image formation 1)
The ink sheet and the image receiving sheets 101 to 114 are processed so that they can be loaded, and in the high-speed print mode, the sublimation type thermal transfer printer ASK2000 (trade name, manufactured by Fuji Photo Film Co., Ltd.) from the lowest density to the highest density. 10 images were output continuously with the setting of obtaining gray gradation in the entire area. At this time, the time from the discharge of the first sheet to the discharge of the second sheet was 8 seconds.

(Dmax evaluation)
The Visual density of the highest density portion of the image output on the second sheet obtained under the above conditions was measured with Photographic Densitometer (trade name, manufactured by X-Rite Incorporated). The results are shown in Table 1 below.

(Evaluation of image quality)
Among the gray gradations obtained with the ASK2000 machine, image unevenness (low-density image unevenness) with a size of 0.1 mm to 1 mm was observed near a Visual density of 0.2. The degree was visually evaluated. When the unevenness was the same as the color print of a commercially available silver salt color paper, it was evaluated as being within an acceptable range. The results are shown in Table 1 below.

  From the above, it can be seen that all the samples of the present invention have a high Dmax density and, at the same time, little image unevenness in the low density portion.

Example 2
(Image formation 2)
The ink sheet and the image receiving sheets 101 to 114 are processed so that they can be loaded. From the lowest density to the highest density by the sublimation type thermal transfer printer CW01 (trade name, manufactured by Citizen Data Systems Co., Ltd.) in the high-speed print mode. 10 images were output continuously with the setting of obtaining gray gradation in the entire area. At this time, the time from the discharge of the first sheet to the discharge of the second sheet was 8 seconds.

(Dmax evaluation)
The Visual density of the highest density portion of the image output on the second sheet obtained under the above conditions was measured with Photographic Densitometer (trade name, manufactured by X-Rite Incorporated). The results are shown in Table 2 below.

(Evaluation of image quality)
Among the gray gradations obtained with the CW01 machine, image irregularities (low-density image irregularities) with a size of 0.1 mm to 1 mm were observed near a Visual density of 0.2. The degree was visually evaluated. When the unevenness was the same as the color print of a commercially available silver salt color paper, it was evaluated as being within an acceptable range. The results are shown in Table 2 below.

  From the above, it can be seen that all the samples of the present invention have a high Dmax density and, at the same time, little image unevenness in the low density portion.

Example 3
In the image receiving sheets 101 to 114, image receiving sheets 201 to 214 were produced in the same manner except that the heat insulating layer was changed to the following configuration.

Heat insulation layer coating liquid (composition)
30 parts by mass of previously fired hollow particles mainly composed of polyacrylonitrile (average particle diameter 3.5 μm, volume hollow ratio 70%)
10 parts by mass of water dispersible acrylic resin (trade name, AE337, manufactured by JSR Corporation)
Partially saponified polyvinyl alcohol 10 parts by mass (Kuraray Co., Ltd., trade name, PVA205)
500 parts by weight of water (amount applied) 162 ml / m ²

(Image formation 2)
The ink sheet and the image receiving sheets 101 to 114 are processed so that they can be loaded, and in a high-speed print mode, the gray density of the entire region from the lowest density to the highest density is increased by the sublimation type thermal transfer printer CW01 (manufactured by Citizen Co., Ltd.). 10 images were output continuously with the setting to obtain gradation. At this time, the time from the discharge of the first sheet to the discharge of the second sheet was 8 seconds.

(Dmax evaluation)
The Visual density of the highest density portion of the image output on the second sheet obtained under the above conditions was measured with Photographic Densitometer (trade name, manufactured by X-Rite Incorporated). The results are shown in Table 3 below.

(Evaluation of image quality)
Among the gray gradations obtained with the CW01 machine, image irregularities (low-density image irregularities) with a size of 0.1 mm to 1 mm were observed near a Visual density of 0.2. The degree was visually evaluated. When the unevenness was the same as the color print of a commercially available silver salt color paper, it was evaluated as being within an acceptable range. The results are shown in Table 3 below.

  From the above, it can be seen that all the samples of the present invention have a high Dmax density and, at the same time, little image unevenness in the low density portion.

Example 4
In the image receiving sheets 101 to 114, multilayer coating compositions having a configuration of an undercoat layer, a heat insulating layer, and a receiving layer were sequentially applied from the lower layer to the multilayer coating. These are designated as image receiving sheets 401-414.
These were imaged in the same manner as in Example 1 and evaluated for Dmax and image quality. As a result, the image receiving sheet of the present invention gave good results.

Claims (14)

On the support, it has at least one receiving layer containing a polymer latex of vinyl chloride acrylic copolymer , and at least one layer between the receiving layer and the support has a particle size of 0.1 to 2 μm. A non-foaming hollow polymer latex formed of polystyrene resin, acrylic resin or styrene-acrylic resin, and a heat insulating layer containing at least one water-soluble polymer or polymer latex, the support being on both sides or at least receiving base paper has a polyolefin resin layer on the side of the surface provided with a layer, and the surface of the receptive layer provided side, Ri 70 g / m ² or less der coating weight is 5 g / m ² or more polyolefin resin layer, the base paper a is a thickness of 50μm or more 300μm or less, the density of the base paper is at 0.9 g / ^{m 3} or more 1.1 g / ^{m 3} or less, and the thickness of the support 100μm Sublimation thermal transfer image receiving sheet, characterized in that at the upper 350μm or less. 2. The sublimation type thermal transfer image receiving sheet according to claim 1, wherein the center line average roughness (Ra) of the surface of the support on which the receiving layer is provided is 0.5 μm or less. The sublimation type thermal transfer image-receiving sheet according to claim 1 or 2, wherein the polymer latex in the receiving layer has a vinyl chloride monomer ratio of 50 to 95%. The sublimation type thermal transfer image-receiving sheet according to any one of claims 1 to 3, wherein the polymer latex in the receiving layer is a polymer latex of a copolymer of vinyl chloride and alkyl acrylate. The sublimation type thermal transfer image receiving sheet according to any one of claims 1 to 4, wherein the heat insulating layer contains a water-soluble polymer. The sublimation type thermal transfer image-receiving sheet according to any one of claims 1 to 4, wherein the heat insulating layer contains gelatin. The sublimation type thermal transfer image-receiving sheet according to any one of claims 1 to 6, wherein the receptor layer contains a water-soluble polymer. The sublimation type thermal transfer image receiving sheet according to any one of claims 1 to 6, wherein the receiving layer contains gelatin. The sublimation type thermal transfer image-receiving sheet according to any one of claims 1 to 8 , wherein the polyolefin resin layer of the support is polyethylene. The sublimation type thermal transfer image-receiving sheet according to any one of claims 1 to 9 , wherein the base paper of the support has a basis weight of 50 g or more and 300 g or less. Said receiving layer and / or the heat insulation layer contains a compound capable of crosslinking the water-soluble polymer, according to claim 1-10 in which part or all of the water soluble polymer is characterized in that it is cross-linked The sublimation type thermal transfer image-receiving sheet according to any one of the above. The sublimation type thermal transfer image-receiving sheet according to any one of claims 1 to 11, further comprising an undercoat layer containing a latex and a binder resin between the support and the heat insulating layer. The sublimation type thermal transfer image-receiving sheet according to any one of claims 1 to 12, further comprising a charge adjusting layer on a back surface side of the support. On said support having a polyolefin resin layer on the surface of the small without even the side provided with the receptive layer of the base paper, the receiving layer coating solution and the coating solution of the heat insulating layer in this order by simultaneous coating sublimation thermal transfer image-receiving sheet according to any one of claims 1 to 13, wherein a is manufactured Rukoto.