JP2008238673A - Thermal transfer image accepting sheet and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermal transfer image accepting sheet which has a high sensitivity and a uniform image quality in a low-density portion, and a manufacturing method thereof. <P>SOLUTION: The thermal transfer image accepting sheet has, on a substrate, at least an undercoat layer, a heat insulating layer and an accepting layer formed in sequence from the substrate side. The heat insulating layer contains at least one kind of hollow polymer, and the viscosity of a coating solution for the undercoat layer is 200 mPa s or less at both 40°C and 15°C. The heat insulating layer, the undercoat layer and the accepting layer are all formed by simultaneous multilayered coating. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a heat-sensitive transfer image-receiving sheet and a method for producing the same, and more particularly to a heat-sensitive transfer image-receiving sheet having high sensitivity and uniform image quality in a low-density portion and a method for producing the same.

  Conventionally, various thermal transfer recording methods are known, and among them, the dye diffusion transfer recording method is attracting attention as a process capable of producing a color hard copy closest to the image quality of a silver salt photograph (for example, Non-Patent Document 1 and 2). In addition, it has the advantages of being dry, being able to visualize directly from digital data, and being easy to duplicate, compared to silver salt photography.

  In this dye diffusion transfer recording system, a thermal transfer sheet containing a pigment (hereinafter also referred to as an ink sheet) and a thermal transfer image receiving sheet (hereinafter also referred to as an image receiving sheet) are superposed, and then heat is generated by an electrical signal. By heating the ink sheet with a controlled thermal head, the dye in the ink sheet is transferred to the image receiving sheet to record image information. By recording three colors of cyan, magenta, and yellow in an overlapping manner, A color image having a continuous change in color shading can be transferred and recorded.

In such a dye diffusion transfer type recording method, it has been known for a long time that it is important to give a high heat insulating property and cushioning property to an image receiving sheet in order to obtain a good image (for example, non-patent document). 1 and 2).
Therefore, in order to provide heat insulation and cushioning properties, a composite support using a biaxially stretched polyolefin film containing microvoids may be used as the base material of the image receiving sheet. However, in this method, the residual stress at the time of stretching is relaxed and contracted by heat at the time of printing and heat at the time of coating the image receiving layer, and wrinkles and curls are generated on the image receiving sheet.

  Other methods for imparting heat insulation and cushioning properties to the image receiving sheet have been studied. For example, a method of forming a foamed layer (for example, Patent Document 3) composed of a resin and a foaming agent between a support and a receiving layer, and a microcapsule-like hollow polymer and an organic solvent-resistant polymer as main components (Patent Document 5). Since these methods can form a heat-insulating layer on a support by a coating method, there is an advantage that generation of wrinkles and curls of an image receiving sheet seen on the composite support can be suppressed. However, it is difficult to obtain a uniform and smooth image-receiving sheet, and there is a drawback that a transfer failure occurs. As a means for solving this problem, when forming an intermediate layer containing a resin containing hollow particles as a main component on a sheet-like support, after applying the intermediate layer-forming paint on the sheet-like support, the coated surface is used as a cast drum. A method for forming an image receiving sheet by pressure bonding (Patent Document 6) has also been proposed. However, although this method can obtain sufficient smoothness, the manufacturing process becomes complicated and disadvantageous in terms of productivity.

  For such a problem, for example, in a heat-sensitive transfer image-receiving sheet having a heat insulating layer and a receiving layer on a support, the heat insulating layer contains a hollow polymer, and the hollow polymer content is 65% by mass or more, A thermal transfer image-receiving sheet is disclosed in which a heat-insulating layer and a layer on the receiving layer side adjacent thereto are formed by simultaneous multilayer coating (Patent Document 7). In the above proposed method, there is no description regarding the undercoat layer, and the coating liquid has a high ratio of the hollow polymer in order to ensure a high filling rate of particles in order to obtain a sufficient heat insulating effect. As a result of studies by the present inventors, when a coating solution having a high hollow polymer ratio is used, the problem that the obtained image quality (uniformity, unevenness) is easily affected by the smoothness of the support has been clarified. This problem occurs only when such a coating solution having a high hollow polymer ratio is used. Moreover, such a problem does not occur in a silver halide photographic light-sensitive material that has been conventionally applied by simultaneous multilayer coating.

  On the other hand, in the thermal transfer image-receiving sheet having a heat insulating layer and a receiving layer on the support in order to suppress the floating of the hollow polymer during the drying process and to obtain excellent image quality uniformity while maintaining a high concentration, at least 1 It is disclosed that a layer, preferably all layers having a viscosity at 40 ° C. of 200 mPa · s or less and a viscosity at 15 ° C. of 20 times or more of the viscosity at 40 ° C., is preferably applied simultaneously. (Patent Document 8). Even in the proposed method, there is a description of the intermediate layer existing between the receiving layer and the heat insulating layer, but there is no description of the undercoat layer. Further, although the smoothness of the thermal transfer receiving sheet derived from the receiving layer and the heat insulating layer is described, the smoothness of the thermal transfer receiving sheet derived from the support is not described.

  Since the smoothness of the surface of the heat-sensitive transfer image-receiving sheet greatly depends on the smoothness of the support, an image with high image quality can be obtained if the smoothness of the support is very high. However, it is difficult and costly to maintain the smoothness of the support at that level.

  From such a background, a thermal transfer image-receiving sheet that achieves high density printing characteristics by making use of the voids of the hollow polymer, and that always achieves high image quality regardless of the smoothness of the support, and its production A method was strongly desired.

Japanese Patent No. 2554196 Japanese Patent No. 3226167 JP-A-5-8572 JP 2006-88691 A JP 2006-68918 A “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

  In view of the above problems, the object of the present invention has high heat insulation by making the best use of a heat insulating layer using a hollow polymer while taking advantage of the simultaneous multilayer coating method, and is not affected by the support. It is an object of the present invention to provide a production method capable of obtaining high image quality, and to provide a thermal transfer image-receiving sheet capable of achieving excellent image formation (having high density printing characteristics and excellent image quality) and a method for producing the same.

As a result of intensive studies, the inventors of the present invention are heat-sensitive transfer image-receiving sheets formed on a support in the order of at least an undercoat layer, a heat insulating layer, and a receiving layer from the support side, and the heat insulating layer is at least one kind. The coating solution for the undercoat layer containing a hollow polymer had a viscosity at 40 ° C. and 15 ° C. of 200 mPa · s or less, and the heat-insulating layer, the undercoat layer, and the receiving layer were all coated simultaneously. It has been found that excellent image formation can be achieved by the heat-sensitive transfer image-receiving sheet. The present invention has been made based on such findings.
The above problems have been achieved by the following means.
(1) A heat-sensitive transfer image-receiving sheet formed on a support in the order of at least an undercoat layer, a heat-insulating layer and a receiving layer from the support side,
The thermal insulation layer comprises at least one hollow polymer;
The viscosity of the coating solution for the undercoat layer at 40 ° C. and 15 ° C. is 200 mPa · s or less,
A heat-sensitive transfer image-receiving sheet, wherein the heat-insulating layer, the undercoat layer, and the receiving layer are all coated simultaneously.
(2) The polymer latex contained in the receiving layer is any one of vinyl chloride / acrylic compound copolymer latex, vinyl chloride / vinyl acetate copolymer latex, vinyl chloride / vinyl acetate / acrylic compound copolymer latex, or The heat-sensitive transfer image-receiving sheet according to (1), which is an arbitrary combination.
(3) The thermal transfer image-receiving sheet as described in (1) or (2), wherein the undercoat layer does not contain gelatin.
(4) The thermal transfer according to any one of (1) to (3), wherein there is a step of less than 15 ° C. within 5 sec immediately after coating, and the passing time of the step is 10 sec or more. Image receiving sheet.
(5) A heat-sensitive transfer image-receiving sheet formed on a support in the order of at least an undercoat layer, a heat-insulating layer and a receiving layer from the support side,
The thermal insulation layer comprises at least one hollow polymer;
The viscosity of the coating solution for the undercoat layer at 40 ° C. and 15 ° C. is 200 mPa · s or less,
A method for producing a heat-sensitive transfer image-receiving sheet, wherein the heat-insulating layer, the undercoat layer and the receptor layer are all coated simultaneously.
(6) The polymer latex contained in the receiving layer is any one of vinyl chloride / acrylic compound copolymer latex, vinyl chloride / vinyl acetate copolymer latex, vinyl chloride / vinyl acetate / acrylic compound copolymer latex, or The method for producing a heat-sensitive transfer image-receiving sheet according to (5), which is an arbitrary combination.
(7) The method for producing a thermal transfer image-receiving sheet according to (5) or (6), wherein the undercoat layer does not contain gelatin.
(8) The thermal transfer according to any one of (5) to (7), wherein there is a step of less than 15 ° C. within 5 sec immediately after coating, and the passing time of the step is 10 sec or more. A method for producing an image receiving sheet.

  The heat-sensitive transfer image-receiving sheet of the present invention has high sensitivity and few image failures. Furthermore, the image is output quietly. Further, it can be manufactured at low cost.

Hereinafter, the present invention will be described in detail.
The heat-sensitive transfer image-receiving sheet of the present invention is a heat-sensitive transfer image-receiving sheet formed on a support in the order of at least an undercoat layer, a heat-insulating layer and a receiving layer from the support side, and the heat-insulating layer contains at least one hollow polymer. In addition, the viscosity of the coating solution of the undercoat layer at 40 ° C. and 15 ° C. is 200 mPa · s or less, and the heat insulating layer, the undercoat layer, and the receiving layer are all formed by simultaneous multilayer coating. The layer on the side of the receiving layer adjacent to the heat insulating layer may be a receiving layer or an intermediate layer having other functions. Moreover, the heat insulation layer and the receiving layer may each be formed of a plurality of layers. An intermediate layer such as a white background adjusting layer, a charge adjusting layer, an adhesive layer, a primer layer, or an undercoat layer may be formed between the support and the heat insulating layer. When the intermediate layer is included, the receiving layer, the heat insulating layer, and the intermediate layer can be formed by simultaneous multilayer coating. A release layer may be formed on the outermost layer on the surface on which the transfer material is superposed.
Furthermore, a curl adjusting layer, a writing layer, and a charge adjusting layer are preferably formed on the back side of the support.

These heat-sensitive image-receiving sheets are prepared by adjusting the coating solution, coating the coating solution on the support, and drying. In the present invention, the receiving layer and the heat insulating layer are each preferably two layers or more, or one of the two or more layers is a preferred embodiment, but at least the layer on the receiving layer side adjacent to the heat insulating layer is applied simultaneously. The layer on the receiving layer side may be a receiving layer or an intermediate layer having other functions.
Hereinafter, this process will be described in detail.
(Preparation of coating solution)
In order to prepare an application liquid finally having liquid properties corresponding to the design quality by measuring and mixing the additives, a known method / apparatus can be used. As a measuring method, methods such as weight measurement and volume measurement can be used. As a stirrer for mixing, a propeller stirrer, a jet agitator, or the like can be used.
When adding gelatin, a method may be employed in which gelatin is dispersed and immersed in water at room temperature to swell the entire gelatin powder, and then heated to dissolve and added.
Various viscometers, surface tension measuring devices, specific gravity meters, pH meters and the like can be used for measuring the liquid physical properties of the coating liquid. The measuring method of the viscosity of the coating liquid is roughly divided into a method of measuring the resistance force applied to the rotating body in the liquid and a method of measuring the pressure loss when passing through the orifice or the thin tube. The former is a rotary viscometer and is typified by a B type viscometer. The latter is a capillary viscometer represented by the Ostwald viscometer. The present invention employs the measured value when measured at 40 ° C. using the former rotary viscometer.

(Application)
The application of each layer can be appropriately selected from known methods such as roll coating, bar coating, gravure coating, gravure reverse coating, die coating, slide coating, curtain coating and the like that allow simultaneous multilayer coating. Among these, curtain coating and slide coating are methods in which the coating film thickness is determined by the flow rate of liquid delivered by a pump or the like, and simultaneous multilayer coating is possible.
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-B-49-7050, or specification, Edgar B. Gutoff et al., "Coating and Drying Defects: Troubleshooting Operating Problems", John Wiley & Sons, 1995. , 101-103, etc., so-called slide coating (slide coating method) and curtain coating (curtain coating method) are known. In these coating methods, a plurality of coating liquids are simultaneously supplied to a coating apparatus to form a plurality of different layers. These methods can obtain a uniform coating film thickness and can simultaneously apply multiple layers, and can be preferably used in the present invention.

As an apparatus for the slide coating method, there is a multilayer slide bead apparatus proposed in US Pat. No. 2,761,791 by Russell et al. Examples of coater shapes are also described in “LIQUID FILM COATING” (CHAPMAN & HALL, 1997) by Stephen F. Kistler and Petert M. Schweizer.
The slide bead coating apparatus mainly includes a coating head and a backup roller that wraps and supports a continuously running support. Inside the block that forms the coating head, there is formed a liquid pool that spreads the coating liquid fed from the liquid feeding line in the width direction of the support, and a narrow slit communicates with this liquid pool up to the slide surface. An opening is formed. This slide surface is formed on the upper surface of the coating head and is inclined downward toward the backup roller side.
The coating liquid supplied to each liquid reservoir is pushed out from each slit to the slide surface, and sequentially overlaps while flowing down the slide surface to form a multi-layer coating film. Reach the tip of the lower end. The coating liquid that has reached the tip forms a coating liquid bead in the gap between the tip and the support surface that is wound around the backup roller and travels, and is applied to the support surface via the coating liquid bead. The lower part is depressurized to stabilize the bead. Therefore, a decompression chamber is formed below the backup roller. The decompression chamber serves to stabilize the bead by setting the lower side of the bead to a negative pressure and to make it easier for excess coating liquid not applied to the web to flow down into the decompression chamber.

  Curtain coating is a method of coating a free-falling liquid film on a support that is continuously running at a constant speed below. There are several methods such as an extrusion type and a slide type. In the slide type coater, the multilayer liquid film created on the slide surface falls freely from the slide end. Therefore, the shape of the slide surface is devised so that a falling liquid film is smoothly formed.

In simultaneous multi-layer coating, it is necessary to adjust the viscosity and surface tension of the coating solution constituting each layer from the viewpoints of forming a uniform coating film and good coating properties. The viscosity of the coating solution can be easily adjusted by using a known thickener or thickener within a range that does not affect other performances. Further, the surface tension of the coating solution can be adjusted by various surfactants.
In the present invention, the viscosity of the undercoat layer is adjusted, and the viscosity at 40 ° C. and 15 ° C. is preferably 200 mPa · s or less, more preferably 150 mPa · s or less, more preferably 120 mPa · s. Most preferably:

In order to feed a coating solution prepared so that the physical properties such as liquid concentration, viscosity, surface tension, pH, etc. are appropriate values, it is necessary to continuously carry out while removing bubbles and foreign substances. is there.
Various methods are possible for continuously supplying the coating liquid at a constant flow rate, but it is preferable to use a metering pump from the viewpoint of accuracy and reliability. Examples include a plunger pump and a diaphragm pump. In the diaphragm type, the plunger and the liquid to be sent are separated by the two diaphragms, and the operation of the plunger is transmitted to the liquid to be sent via the drive oil and the pure water between the two diaphragms. It is done. Variations in the flow rate of the liquid feed pump lead to variations in the coating film thickness, and sufficient accuracy is required.
When it is necessary to reduce the influence of the pump pulsation, an auxiliary device for absorbing the pulsation is used. Some methods are known, but one example is a pipeline type pulsation absorbing device (Japanese Patent Laid-Open No. 1-255793).

In order to remove foreign matter, it is preferable to filter the coating solution. Various kinds of filter media can be used, and a cartridge filter medium can be given as an example. In use, it is preferable to treat in advance in order to prevent air retained in the pores of the filter medium from being mixed into the coating liquid in the form of bubbles. Several methods are known, but an example is treatment with a liquid containing a surfactant (US5096602).
Along with foreign matter, bubbles also cause coating surface failure. For this reason, it is preferable to defoam and defoam bubbles that are mixed in the coating liquid and foams that are floating on the liquid surface. As a technique for this purpose, there is separation of bubbles from liquid or dissolution of bubbles in liquid. As separation methods, vacuum defoaming, ultrasonic defoaming, centrifugal defoaming and the like are known. Examples of the method for dissolving in a liquid include ultrasonic pipeline defoaming.
When using an additive that deteriorates the aging stability of the coating solution by adding it to the coating solution, in order to shorten the aging time from adding to coating, A method of adding just before is known. Such a method can also be used in the present invention. As a mixer for this purpose, there are a static mixer and a dynamic mixer.

(Dry)
After coating, the coated product having a coating film formed on the support is dried in a drying zone and wound up through a humidity control zone. In the present invention, it is preferable to quickly solidify after forming a laminate of a plurality of layers on a support. When strong drying air is applied at a stage where the coating film is not sufficiently solidified, fluidity is generated, resulting in unevenness. Further, when the uppermost layer of the coating film contains an organic solvent, nonuniform solvent evaporation occurs on the slide surface or immediately after coating due to the wind, resulting in unevenness. From this point of view, aqueous coating is advantageous.
In addition, when a binder that gels at low temperature such as gelatin is formed, after forming a plurality of layers on the support, the temperature is quickly lowered and the coating film is cooled and solidified (setting process), and then the temperature is raised and dried. preferable. Thereby, a further uniform and homogeneous coating film is formed.
Here, the setting step is, for example, a gelation accelerating step for increasing the viscosity of the coating composition by means of lowering the temperature by applying cold air or the like to the coating and slowing the material fluidity in each layer and each layer. Means that.
In the present invention, the temperature condition of the setting step when cold air is used is preferably 15 ° C. or less, and more preferably 10 ° C. or less. The time for which the coating film is exposed to the cold air depends on the coating conveyance speed, but is preferably 10 seconds or longer and 120 seconds or shorter, and more preferably 15 seconds or longer and 100 seconds or shorter.
In the present invention, as described above, the undercoat layer preferably has a viscosity at 40 ° C. and 15 ° C. of 200 mPa · s or less, more preferably 150 mPa · s or less, and 120 mPa · s or less. Most preferably it is. The undercoat layer preferably does not contain raw materials, chemicals and the like that enhance setability in the setting step. Specifically, it is preferable not to add various known gelling agents such as gelatin, pectin, agar, carrageenan, and gellan gum to the undercoat layer coating solution.
In the present invention, since the latex mainly constitutes the coating solution, if it is dried quickly, the film shrinks due to drying, resulting in cracks in the coated film after drying, and it is preferable to dry slowly. In order to satisfy these requirements, the drying process needs to be dried while adjusting the drying speed, adjusting the drying temperature, the amount of drying air, and the dew point of the drying air.

  As a typical drying apparatus, there are an air loop method, a hanger method, and the like. The air loop method is a method in which a dry air jet is blown onto a coated product supported by a roller, and there are a method in which a duct is arranged vertically and a method in which a duct is arranged horizontally. The drying function and the transport function are basically separated, and the degree of freedom such as the air volume is large. However, since many rollers are used, poor conveyance of the base such as slippage, wrinkles, and slips is likely to occur. The helical winding method is a method in which the coated product is wound around a cylindrical duct in a helical shape, and is floated with dry air (air floating), transported and dried. Basically, no roller support is required. 20438). In the present invention, these drying apparatuses can be preferably used.

Hereinafter, the configuration of the heat-sensitive image-receiving sheet of the present invention will be described in detail.
(Receptive layer)
The receiving layer serves to receive the dye transferred from the ink sheet and maintain the formed image. In the image receiving sheet of the present invention, the receiving layer contains a polymer latex.
The receiving layer can contain an ultraviolet absorber, a release agent, a lubricant, an antioxidant, a preservative, a surfactant, and other additives.

<Polymer latex>
The polymer latex used in the present invention will be described. In the heat-sensitive transfer image-receiving sheet of the present invention, the polymer latex that can be used in the receptor layer is a water-insoluble hydrophobic polymer dispersed as fine particles in a water-soluble dispersion medium. As the dispersion state, the polymer is emulsified in a dispersion medium, the emulsion is polymerized, the micelle is dispersed, or the polymer molecule has a partially hydrophilic structure and the molecular chain itself is molecularly dispersed. Anything may be used. For polymer latex, Tadashi Okuda, Hiroshi Inagaki, “Synthetic Resin Emulsion”, published by Kobunshi Publishing (1978), Takaaki Sugimura, 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 (Tg) of the polymer latex of the present invention is preferably -30 ° C to 130 ° C, more preferably 0 ° C to 120 ° C. Among these, the glass transition temperature is preferably 40 ° C or higher (preferably 40 to 120 ° C), and more preferably 70 ° C or higher (70 to 100 ° C).

  Preferred embodiments of the polymer latex of the present invention include polymer latexes such as acrylic polymers, polyesters, rubbers (for example, SBR resin), polyurethanes, polyvinyl chlorides, polyvinyl acetates, polyvinylidene chlorides, and polyolefins. Can be preferably used. The polymer latex may be a linear polymer, a branched polymer, a crosslinked polymer, a so-called homopolymer obtained by polymerizing a single monomer, or a copolymer obtained by polymerizing two or more monomers. Good. 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 for the synthesis of the polymer latex used in the present invention is not particularly limited, and monomers that can be polymerized by a normal radical polymerization or ionic polymerization method are preferably the following monomer groups (a) to (j). Can be 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, tetrahydrofurfuryl meta Relate, 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 (For example, monobutyl maleate, dimethyl maleate, monomethyl itaconate, dibutyl itaconate, etc.), polyfunctional esters (for example, ethylene glycol diacrylate, Tylene glycol dimethacrylate, 1,4-cyclohexanediacrylate, pentaerythritol tetramethacrylate, pentaerythritol triacrylate, trimethylolpropane triacrylate, trimethylolethane triacrylate, dipentaerythritol pentamethacrylate, pentaerythritol hexaacrylate, 1,2, 4-cyclohexanetetramethacrylate and the like.

(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-tert-butyl 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.

  The polymer latex that can be used in the present invention is commercially available, and the following polymers can be used. Examples of acrylic polymers include Sebian A-4635, 4718, 4601 manufactured by Daicel Chemical Industries, Ltd., Nipol Lx811, 814, 821, 820, 855 (P-17: Tg36 ° C.) manufactured by Zeon Corporation, 857x2. (P-18: Tg43 ° C), Dainippon Ink Chemical Co., Ltd. Voncoat R3370 (P-19: Tg25 ° C), 4280 (P-20: Tg15 ° C), Nippon Pure Chemical Co., Ltd. Jurimer ET-410 ( P-21: Tg44 ° C), JSR AE116 (P-22: Tg50 ° C), AE119 (P-23: Tg55 ° C), AE121 (P-24: Tg58 ° C), AE125 (P-25: Tg60) ° C), AE134 (P-26: Tg48 ° C), AE137 (P-27: Tg48 ° C), AE140 (P-28: Tg53 ° C), AE173 (P-29: Tg60 ° C), Aron from Toagosei Co., Ltd. A-104 (P-30: Tg45 ° C), NS-600X, NS-620X, manufactured by Takamatsu Yushi Co., Ltd., Vinibrand 2580, 2583, 2641, 2770, 2770H, 2635, 2886, 5202C, manufactured by Nissin Chemical Industry Co., Ltd. , 2706, etc. (all are trade names).

Examples of polyesters include FINETEX ES650, 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-21, 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, NS-140L, NS-141LX, NS-282LX, Aronmelt PES-1000 series, PES-2000 series manufactured by Toagosei Co., Ltd., Baironal MD-1100 manufactured by Toyobo Co., Ltd., MD- 1200, MD-1220, MD-1245, MD-1250, MD-1335, MD-1400, MD-1480, MD-1500, MD-1930, MD-1985, Sephorjon ES manufactured by Sumitomo Seika Co., Ltd. (Both are trade names).

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

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

  Examples of polyvinyl chlorides include: Z351, G351, G576, Nissin Chemical Industry Co., Ltd., Vinibrand 240, 270, 277, 375, 386, 609, 550, 601, 602, 630, 660, 671, 683, 680, 680S, 681N, 685R, 277, 380, 381, 410, 430, 432, 860, 863, 865, 867, 900, 900GT, 938, 950, etc. (all are trade names). Examples of polyvinylidene chlorides include L502 and L513 manufactured by Asahi Kasei Kogyo Co., Ltd., and D-5071 manufactured by Dainippon Ink & Chemicals, Inc. (all are trade names). Examples of polyolefins include Chemipearl S120, SA100, V300 (P-40: Tg80 ° 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 copolymerized nylons include Sepoljon PA manufactured by Sumitomo Seika Co., Ltd. (all are trade names).

  Examples of polyvinyl acetates include Nishin Chemical Industry Co., Ltd.ViniBran 1080, 1082, 1085W, 1108W, 1108S, 1563M, 1566, 1570, 1588C, A22J7-F2, 1128C, 1137, 1138, A20J2, A23J1, A23J1, A23K1, A23P2E, A68J1N, 1086A, 1086, 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, 1107L, 1225, 1245L, GV-6170, GV-6181, 4468W, 4468S, etc. Product name).

These polymer latexes may be used alone or in combination of two or more as required. As the polymer latex of the present invention, any one or any combination of vinyl chloride / acrylic compound copolymer latex, vinyl chloride / vinyl acetate copolymer latex, vinyl chloride / vinyl acetate / acrylic compound copolymer latex may be used. Preferably, vinyl chloride / acrylic compound copolymer latex is most preferable.
The preferred polymer latex here is preferably one that is compatible with the dye in order to accept the dye that migrates from the ink sheet, while being difficult to be compatible with the binder in which the dye of the ink sheet is dispersed. Is preferred. When a polymer latex that is compatible with the dye is used, the maximum transfer density is increased and an image having a sharp image can be obtained. When a polymer latex that is compatible with the binder in which the dye of the ink sheet is dispersed is used, peeling noise is likely to occur when the ink sheet and the thermal transfer receiving sheet are heated after being overlapped. The easier the polymer latex is compatible, the greater the peeling noise, and eventually the peeling line (banding) occurs when the ink sheet peels.

  In the present invention, at least one receiving layer is applied with an aqueous coating solution. When a plurality of receiving layers are provided, all of these receiving layers should be prepared by applying an aqueous coating solution and then drying. Is preferred. 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.

  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.

  Preferable examples of the polymer latex used in the present invention include polylactic acid esters, polyurethanes, polycarbonates, polyesters, polyacetals, SBRs, and polyvinyl chlorides. Among these, polyesters, polycarbonates Most preferably, polyvinyl chlorides are included.

In the present invention, polyvinyl chlorides are preferable among the above polymer latexes. Among the polyvinyl chlorides, that is, the polymer latex containing at least a repeating unit obtained from vinyl chloride, a polymer latex containing 50 mol% or more of a repeating unit obtained from the vinyl chloride is preferable, and a copolymerized latex is more preferable. is there. As such a copolymer latex, it is preferable that the monomer copolymerized with vinyl chloride is acrylic or methacrylic acid or an ester thereof, vinyl acetate or ethylene. Also preferred are vinyl chlorides and copolymers of acrylic and vinyl acetate. Acrylic or methacrylic acid or its ester is more preferred, and acrylic acid ester is more preferred. The alcohol part of the ester part of the acrylate ester preferably has 1 to 10 carbon atoms, and more preferably 1 to 8 carbon atoms.
Examples of such polyvinyl chlorides include those mentioned above, among others, ViniBran 240, ViniBran 270, ViniBran 276, ViniBran 277, ViniBran 375, ViniBran 380, ViniBran 386, ViniBran 410, ViniBran 430, ViniBran 432, VINYBRAN 550, VINYBRAN 601, VINYBRAN 602, VINYBRAN 609, VINYBRAN 619, VINYBRAN 680, VINYBRAN 680S, VINYBRAN 681N, VINYBRAN 683, VINYBRAN 685R, VINYBRAN 690, VINYBRAN 860, VINYBRAN 863, VINYBRAN 685, VINYBRAN 867, VINYBRAN 900, , ViniBran 950 (all are Nissin Chemical Industry Co., Ltd., SE1320, S-830 (all are Sumitomo Chemtech ( )) Is preferable.

The polymer latex used in the present invention is used for receiving the dye that migrates from the ink sheet, but any polymer may be used in combination with the polymer latex.
The polymer that can be used in combination may be used for receiving a dye, but may also be used as a binder for holding the polymer latex.
Such polymers are preferably transparent or translucent and colorless, and are natural resins, polymers and copolymers, synthetic resins, polymers and copolymers, and other media forming films such as gelatins, polyvinyl alcohols, hydroxys. Ethyl cellulose, cellulose acetate, cellulose acetate butyrate, polyvinyl pyrrolidone, casein, starch, polyacrylic acid, polymethyl methacrylic 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, poly salts Vinylidene, polyepoxides, polycarbonates, polyvinyl acetates, polyolefins, and polyamides. The binder may be coated from water or an organic solvent or emulsion.

  In addition to the polymer latex used for the purpose of receiving the dye migrating from the ink sheet, when used mainly as the binder, the polymer latex has a glass transition temperature (from the viewpoint of processing brittleness and image storage stability). Tg) is preferably in the range of -30 ° C to 70 ° C, more preferably in the range of -10 ° C to 50 ° C, still more preferably in the range of 0 ° C to 40 ° C. It is also possible to use a blend of two or more polymers as the binder, and in this case, it is preferable that the weighted average Tg in consideration of the composition falls within the above range. Moreover, when phase-separating or having a core-shell structure, the weighted average Tg is preferably within the above range.

This glass transition temperature (Tg) can be calculated by the following formula.
1 / Tg = Σ (Xi / Tgi)
Here, it is assumed that n monomer components from i = 1 to n are copolymerized in the polymer. Xi is the weight fraction of the i-th monomer (ΣXi = 1), and Tgi is the glass transition temperature (absolute temperature) of the homopolymer of the i-th monomer. However, Σ is the sum from i = 1 to n. In addition, the value of the homopolymer glass transition temperature (Tgi) of each monomer can adopt the value of “Polymer Handbook (3rd Edition)” (J. Brandrup, EHImmergut (Wiley-Interscience, 1989)).
In addition, although the glass transition temperature of the said polymer latex for receiving the dye in this invention and the hollow polymer mentioned later is prescribed | regulated by a measured value, it is also possible to estimate with said calculation method.

<Water-soluble polymer>
In the present invention, it is one of preferred embodiments that the receiving layer contains a water-soluble polymer.
Here, the water-soluble polymer may be dissolved in an amount of 0.05 g or more with respect to 100 g of water at 20 ° C., more preferably 0.1 g or more, still more preferably 0.5 g or more, and particularly preferably 1 g or more. The polymer latex is obtained by dispersing polymer fine particles in a dispersion medium, and is different from the water-soluble polymer of the present invention.
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.
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. Plant polysaccharides include gum arabic, κ-carrageenan, ι-carrageenan, λ-carrageenan, guar gum (such as Supercol from Squall), locust bean gum, pectin, tragacanth, corn starch (Purity- from National Starch & Chemical Co.) 21), phosphorylated starch (National 78-1898 made by National Starch & Chemical Co.), and other microbial polysaccharides such as xanthan gum (Kelco Keltrol T, etc.) and dextrin (Nadex360 made by National Starch & Chemical Co., etc.) Examples of animal natural polymers include gelatin (such as Crodyne B419 from Croda), casein, sodium chondroitin sulfate (such as Cromoist CS from Croda), and the like (all are trade names). Cellulose systems include ethyl cellulose (ICI Cellofas WLD, etc.), carboxymethyl cellulose (Daicel CMC, etc.), hydroxyethyl cellulose (Daicel HEC, etc.), hydroxypropyl cellulose (Aqualon Klucel, etc.), methyl cellulose (Henkel Viscontran, etc.), Examples include nitrocellulose (such as Isopropyl Wet from Hercules) and cationized cellulose (such as Crodacel QM from Croda). Other starches such as phosphorylated starch (National Starch &Chemical's National 78-1898) and alginic acid are sodium alginate (such as Kelco's Keltone) and propylene glycol alginate. Hi-care1000, etc.) and sodium hyaluronate (Hyalure, etc. from Lifecare Biomedial) are included (all are trade names).
In the present invention, gelatin is one of the preferred embodiments. The gelatin used in the present invention may have a molecular weight of 10,000 to 1,000,000. The gelatin used in the present invention may contain anions such as Cl- and SO42-, and may contain cations such as Fe2 +, Ca2 +, Mg2 +, Sn2 + and Zn2 +. 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)).

  Also, a highly water-absorbing polymer described in US Pat. No. 4,960,681, JP-A-62-245260, ie, a vinyl monomer having —COOM or —SO 3 M (M is a hydrogen atom or an alkali metal). Or a copolymer of these vinyl monomers with each other or other vinyl monomers (for example, sodium methacrylate, ammonium methacrylate, Sumikagel L-5H (trade name) manufactured by Sumitomo Chemical Co., Ltd.) can also be used. .

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 mass%, viscosity (4 mass%, 20 ° C.) 39.5 ± 4.5 CPS], PVA-124 [PVA content 94.0 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% by mass, saponification degree 97.5 ± 0.5 mol%, sodium acetate content 1.0% by 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 quality %, 20 ℃) 25.0 ± 3.5CPS] (or more, both of Kuraray Co., Ltd., trade name of) such as,

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

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

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

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

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

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

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

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

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

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. Moreover, it is also one of the preferable aspects that a water-soluble polymer is not used.

<Polymers other than water-soluble polymers>
Polymers other than water-soluble polymers used as binders in the present invention can be easily obtained by solution polymerization, suspension polymerization, emulsion polymerization, dispersion polymerization, anionic polymerization, cationic polymerization, etc. The emulsion polymerization method obtained as is most preferable. 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 the mixture is polymerized 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 Publishing Association (1978), Takaaki Sugimura, Akio Kataoka, Junichi Suzuki, Keiji Kasahara, "Application of Synthetic Latex", Published by Polymer Publishing Society (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 a radical generating ability, such as inorganic peroxides such as persulfate and hydrogen peroxide, and peroxides described in Nippon Oil & Fats Co., Ltd. “Organic Peroxide Catalog”, etc. The azo compounds described in Yaku Kogyo Co., Ltd. “Azo Polymerization Initiator Catalog” can be used. Among them, water-soluble peroxides such as persulfate and water-soluble azo compounds described in Wako Pure Chemical Industries, Ltd., `` Azo polymerization initiator catalog '' and the like 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, ammonium persulfate, sodium persulfate, potassium persulfate, etc. Peroxides are preferred from the viewpoints of image storage stability, 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. A chelating agent is a compound capable of coordinating (chelating) a multivalent ion such as a metal ion such as iron ion or an alkaline earth metal ion such as calcium ion. Japanese Patent Publication No. 6-8956, US Pat. JP-A-73645, JP-A-4-127145, JP-A-4-47073, JP-A-4-305572, JP-A-6-11805, JP-A-5-1773312, JP-A-5-66527, JP-A-5- 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, 7-120894, JP 7-199433, JP 7-306504, JP 9-43792, JP 8-314090, JP 10-182571, JP 10-182570. The compounds described in JP-A-11-190892 can be used.

  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, West German Patent 1045373, etc.), polyphenol chelating agents, polyamine chelating compounds, etc. Preferably Amino 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-diaminobuta -N, N, N ', N'-tetraacetic 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′-tetraacetic 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′-tetra Acetic 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-p Lopandiamine-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 Examples include substituted alkali metal salts such as sodium and potassium, and ammonium salts.

  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.

  In the polymer latex used in the present invention, an aqueous solvent can be used as a solvent in the coating solution, but a water-miscible organic solvent may be used in combination. Examples of the water-miscible organic solvent include alcohols such as methyl alcohol, ethyl alcohol and propyl alcohol, cellosolves such as methyl cellosolve, ethyl cellosolve and butyl cellosolve, ethyl acetate and dimethylformamide. The amount of these organic solvents added is preferably 40% or less, more preferably 30% or less of the solvent.

The polymer latex used in the present invention preferably has a polymer concentration of 10 to 70% by mass, more preferably 20 to 60% by mass, and particularly preferably 30 to 55% by mass with respect to the latex liquid.
The addition amount of the polymer latex is preferably 50 to 95% by mass, more preferably 70 to 90% by mass, based on the total polymer content in the receptor layer.
In addition, the polymer latex in the image-receiving sheet of the present invention includes a gel or dry film state formed by drying a part of the solvent after coating.

  As the binder for the receiving layer in the present invention, polyurethanes, styrene-butadiene copolymers, polyvinyl alcohol, and gelatin are preferable, and water-soluble polyvinyl alcohol and gelatin are more preferable, and gelatin is most preferable.

<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 and preferably has a mass average molecular weight of 10,000 or more, more preferably a mass 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 release agent, silicone oil and phosphoric ester plasticizer fluorine compound can be used, and silicone oil is particularly 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. The reaction product of vinyl modified silicone oil and hydrogen modified silicone oil is good. The addition amount of the release agent is preferably 0.2 to 30 parts by mass with respect to the receiving polymer.
The lubricant described in the emulsion section below is almost synonymous with the same effect as the release agent described here. In this invention, what was used as a dispersion for convenience was made into the mold release agent demonstrated here as a lubricant emulsion and the other thing.

<Emulsions>
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 (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, and 4,555,476 In addition, a high boiling point organic solvent as described in the publications and specifications of JP 4,599,296 and JP-B-3-62256 is used in combination with a low boiling point organic solvent having a boiling point of 50 ° C to 160 ° C as necessary. Can be used. These lubricants, antioxidants, high-boiling organic solvents and the like can be used in combination of two or more.
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. Silicone compounds such as various waxes, fluorine compounds represented by fluorine surfactants, silicone surfactants, silicone oils and / or cured products thereof are preferably used.

<Matting agent>
In the present invention, it is preferable to add a matting agent for imparting releasability. The matting agent is preferably contained in the outermost surface layer, the layer functioning as the outermost surface layer of the heat-sensitive transfer image-receiving sheet, or a layer close to the outer surface. The outermost surface layer can be made into two layers as required. Most preferably, it is added to the outermost receiving layer. The matting agent can be added to both the outermost layer on the image forming layer surface and the outermost layer on the back surface, and can also be added to both layers. In particular, it is preferable to include a matting agent on the side of the support containing the slip agent.

  The matting agent is preferably dispersed in advance with a binder and used as a matting agent particle dispersion.

  Examples of the matting agent generally include fine particles of an organic compound insoluble in water and fine particles of an inorganic compound. In the present invention, fine particles containing an organic compound are preferable from the viewpoint of dispersibility. As long as it contains an organic compound, it may be an organic compound fine particle composed of an organic compound alone, or an organic / inorganic composite fine particle containing not only an organic compound but also an inorganic compound. Examples of the matting agent include, for example, U.S. Pat. Nos. 1,939,213, 2,701,245, 2,322,037, 3,262,782, 3,539,344, Those well known in the silver salt sensitive material industry such as the organic matting agent described in each specification such as US Pat. No. 3,767,448 can be used.

Since the temperature of the receiving layer surface becomes high during image printing, the matting agent preferably has heat resistance.
In particular, a polymer having a thermal decomposition temperature of 200 ° C. or higher is preferable. More preferably, it is a polymer having a thermal decomposition temperature of 240 ° C. or higher. In addition, when the image is printed, not only heat but also pressure is applied to the surface of the receiving layer.

  The matting agent contained in the outermost layer on the image forming layer side and the outermost layer adjacent layer is dispersed in advance with a binder and used as a matting agent particle dispersion. The dispersion method is (a) a matting agent. The dispersion of the matting agent by removing the low boiling point organic solvent from the emulsion by emulsifying and dispersing the polymer to be dissolved in an aqueous medium as a solution (for example, dissolved in a low boiling point organic solvent) to obtain polymer droplets There are two methods: (b) a method in which fine particles such as a polymer to be a matting agent are prepared in advance, and a dispersion is prepared so as not to cause lumps in an aqueous medium. In the present invention, in consideration of the environment, the method (b) in which a low-boiling organic solvent is not discharged to the environment is preferable.

  Since the dispersion state of the mat particle dispersion in the present invention is stabilized when it contains a surfactant, it is preferable to add a surfactant.

<Surfactant>
In the heat-sensitive transfer image-receiving sheet of the present invention, a surfactant can be contained in the above arbitrary layer. Among these, it is preferable to make it contain in a receiving layer and an intermediate | middle layer.
The addition amount of the surfactant is preferably 0.01 to 5% by mass, more preferably 0.01 to 1% by mass, and 0.02 to 0.2% by mass with respect to the total solid content. It is particularly preferred that
Various surfactants such as anionic, nonionic, and cationic surfactants are known. As the surfactant that can be used in the present invention, known ones can be used. For example, those introduced in “Supervision of Functional Surfactant / Mitsuo Tsunoda, Issued / August 2000, Chapter 6” Among them, an anionic fluorine-containing surfactant is preferable.
Application is possible even when no surfactant is contained, but since the surface tension of the application liquid is high, the application surface may be uneven and uneven. By containing a surfactant in the coating solution, the surface tension can be lowered, unevenness during coating can be eliminated, the coated surface can be made uniform, and coating can be performed stably.

  Although the specific example of a fluorine compound is illustrated below, the fluorine compound which can be used by this invention is not restrict | limited at all by the following specific examples. Unless otherwise specified, the alkyl group and perfluoroalkyl group in the structure notation of the following exemplified compounds means a group having a linear structure.

  These fluorine compounds are used as a surfactant in a coating composition for forming a layer constituting a heat-sensitive transfer image-receiving sheet (in particular, a receiving layer, a heat insulating layer, a protective layer, an undercoat layer, a back layer, etc.). However, in the present invention, it can be preferably contained in the receiving layer and the intermediate layer.

<Preservative>
If the coating solution, the image receiving sheet, the print image, and the like are stored, microorganisms (particularly bacteria, mold, yeast, etc.) adhere to these materials during storage, and their performance is often lowered. In order to prevent this, a preservative can be contained in a range that does not affect other performances.
The preservative referred to in the present invention is a compound used to suppress the compound used in the image-receiving sheet from undergoing a decomposition reaction due to the growth of the microorganism, and the definition and specific compound by the general formula are Handbook, Gihodo Publishing (1986), Hiroshi Horiguchi, Antibacterial and Funeral Chemistry, Sankyo Publishing (1986), Antibacterial and Antifungal Encyclopedia, Japanese Antibacterial and Antifungal Society (1986).
The preservative contained in the image-receiving sheet of the present invention is not particularly limited, but phenol or derivatives thereof, formalin, imidazole derivatives, sodium dehydroacetate, 4-isothiazolin-3-one derivatives, benzoisothiazoline-3-one, benzo Triazole derivatives, amiding anidine derivatives, quaternary ammonium salts, derivatives such as pyrrolidine, quinoline, guanidine, diazine, triazole derivatives, oxazole, oxazine derivatives, 2-mercaptopyridine-N-oxide or salts thereof, formaldehyde donor antibacterial agents, etc. Can be mentioned. Among these, phenol or a derivative thereof, 4-isothiazolin-3-one derivative, benzisothiazolin-3-one, and the like are preferable.

一般式〔Ｉ〕中、Ｒ_１、Ｒ_２は同じでも異なっていてもよく、水素原子、ヒドロキシ基、又は低級アルキル基を表す。Ｘは水素原子、ハロゲン原子、ニトロ基、シアノ基、アリール基、低級アルキル基、低級アルケニル基、アラルキル基、アルコキシ基、−ＣＯＲ_３、−ＳＯ_２Ｒ_４、又は−Ｎ（Ｒ_５）Ｒ_６を表し、Ｒ_３、Ｒ_４は水素原子、−ＯＭ、低級アルキル基、低級アルコキシ基、又は−Ｎ（Ｒ_７）Ｒ_８を表す。
Ｒ_５、Ｒ_６は同じでも異なっていてもよく、水素原子、低級アルキル基、−ＣＯＲ_９、又は−ＳＯ_２Ｒ_１０を表わす。Ｒ_９、Ｒ_１０は低級アルキル基、又は−Ｎ（Ｒ_１１）Ｒ_１２を表し、Ｒ_７、Ｒ_８、Ｒ_１１、Ｒ_１２は同じであっても異なっていてもよく水素原子又は低級アルキル基を表す。
Ｍは、水素原子、アルカリ金属原子又は１価のカチオンを形成するに必要な原子群を表わし、ｌは２〜６の整数を表し、ｍは１〜４までの整数を表し、ｎは６−ｍの整数を表す。ただし、Ｒ_１、Ｒ_２、Ｘが複数存在する時はそれぞれが互いに異なっていてもよい。

一般式〔II〕中、Ｒ_１３は水素原子、アルキル基、アルケニル基、アラルキル基、アリール基、複素環基、

を表し、Ｒ_１４、Ｒ_１５は各々水素原子、アルキル基、アリール基、シアノ基、複素環基、アルキルチオ基、アルキルスルホキシ基、アルキルスルホニル基を表し、Ｒ_１４とＲ_１５は互いに結合して芳香環を形成していても良い。
Ｒ_１６、Ｒ_１７は各々水素原子、アルキル基、アリール基、アラルキル基を表す。
これらの中でも、Ｒ_１４，Ｒ_１５が水素原子であり、Ｒ_１３がメチル基であるもの（以下、化合物ＩＩ−ａと称する）が好ましい。また、Ｒ_１４とＲ_１５が互いに結合して芳香環を形成しＲ_１３が水素原子であるものと化合物ＩＩ−ａとの組み合わせ、および、Ｒ_１４が塩素原子、Ｒ_１５が水素原子、Ｒ_１３がメチル基であるものと化合物ＩＩ−ａとの組み合わせはさらに好ましい。

一般式〔III〕中、Ｒ_１８は水素原子、アルキル基、ヒドロキシメチル基を表わし、Ｒ
_１９は水素原子、アルキル基を表す。

一般式〔IV〕式中、Ｒ_２０は低級アルキレン基を表し、Ｘは水素原子、ハロゲン原子、ニトロ基、ヒドロキシ基、シアノ基、低級アルキル基、低級アルコキシ基、−ＣＯＲ_２１、−Ｎ（Ｒ_２２）Ｒ_２３、−ＳＯ_３Ｍを表し、Ｒ_２１は水素原子、−ＯＭ、低級アルキル基、アリール基、アラルキル基、低級アルコキシ基、アリールオキシ基、アラルキルオキシ基、−Ｎ（Ｒ_２４）Ｒ_２５を表す。
Ｒ_２２、Ｒ_２３は各々水素原子、低級アルキル基、アリール基、アラルキル基、-ＣＯＲ_２６、−ＳＯ_２Ｒ_２６を表し、互に同じであっても異なっていてもよく、Ｒ_２４、Ｒ_２５は各々水素原子、低級アルキル基、アリール基、アラルキル基を表わし、互に同じであっても異なっていてもよく、Ｒ_２６は低級アルキル基、アリール基、アラルキル基を表わし、Ｍは水素原子、アルカリ金属原子及び１価のカチオンを形成するに必要な原子群を表し、ｐは０または１を表わし、ｑは０または１から５までの整数を表わす。 Besides these, compounds represented by any one of the following general formulas [I] to [IV] can be used as preservatives.

In general formula [I], R ₁ and R ₂ may be the same or different and each represents a hydrogen atom, a hydroxy group, or a lower alkyl group. X is a hydrogen atom, a halogen atom, a nitro group, a cyano group, an aryl group, a lower alkyl group, a lower alkenyl group, an aralkyl group, an alkoxy group, —COR ₃ , —SO ₂ R ₄ , or —N (R ₅ ) R _6. R ₃ and R ₄ represent a hydrogen atom, —OM, a lower alkyl group, a lower alkoxy group, or —N (R ₇ ) R ₈ .
R ₅ and R ₆ may be the same or different and each represents a hydrogen atom, a lower alkyl group, —COR ₉ , or —SO ₂ R ₁₀ . R ₉ and R ₁₀ represent a lower alkyl group or —N (R ₁₁ ) R ₁₂ , and R ₇ , R ₈ , R ₁₁ , and R ₁₂ may be the same or different, and may be a hydrogen atom or a lower alkyl group. Represents.
M represents a hydrogen atom, an alkali metal atom, or an atomic group necessary to form a monovalent cation, l represents an integer of 2 to 6, m represents an integer of 1 to 4, and n represents 6- represents an integer of m. However, when there are a plurality of R ₁ , R ₂ , and X, each may be different from each other.

In general formula [II], R ₁₃ represents a hydrogen atom, an alkyl group, an alkenyl group, an aralkyl group, an aryl group, a heterocyclic group,

R ₁₄ and R ₁₅ each represent a hydrogen atom, an alkyl group, an aryl group, a cyano group, a heterocyclic group, an alkylthio group, an alkylsulfoxy group, or an alkylsulfonyl group, and R ₁₄ and R ₁₅ are bonded to each other. An aromatic ring may be formed.
R ₁₆ and R ₁₇ each represent a hydrogen atom, an alkyl group, an aryl group, or an aralkyl group.
Among these, those in which R ₁₄ and R ₁₅ are hydrogen atoms and R ₁₃ is a methyl group (hereinafter referred to as compound II-a) are preferable. In addition, R ₁₄ and R ₁₅ are bonded to each other to form an aromatic ring and R ₁₃ is a hydrogen atom in combination with Compound II-a, and R ₁₄ is a chlorine atom, R ₁₅ is a hydrogen atom, R ₁₃ The combination of the compound in which is a methyl group and compound II-a is further preferred.

In the general formula [III], R ₁₈ represents a hydrogen atom, an alkyl group or a hydroxymethyl group;
₁₉ represents a hydrogen atom or an alkyl group.

In the general formula [IV], R ₂₀ represents a lower alkylene group, X represents a hydrogen atom, a halogen atom, a nitro group, a hydroxy group, a cyano group, a lower alkyl group, a lower alkoxy group, —COR ₂₁ , —N (R ₂₂ ) represents R ₂₃ , —SO ₃ M, R ₂₁ represents a hydrogen atom, —OM, lower alkyl group, aryl group, aralkyl group, lower alkoxy group, aryloxy group, aralkyloxy group, —N (R ₂₄ ) R ₂₅ .
R ₂₂ and R ₂₃ each represent a hydrogen atom, a lower alkyl group, an aryl group, an aralkyl group, —COR ₂₆ , or —SO ₂ R _{26, and} may be the same or different from each other, and R ₂₄ , R ₂₅ Each represents a hydrogen atom, a lower alkyl group, an aryl group or an aralkyl group, and may be the same or different from each other, R ₂₆ represents a lower alkyl group, an aryl group or an aralkyl group, M represents a hydrogen atom, An atomic group necessary for forming an alkali metal atom and a monovalent cation is represented, p represents 0 or 1, and q represents 0 or an integer from 1 to 5.

  Any one of the preservatives may be used alone, or two or more arbitrary compounds may be selected and used in combination. The preservative may be added as it is, but it may be dissolved in water or an organic solvent such as methanol, ethanol, isopropyl alcohol, acetone, ethylene, or ethylene glycol, and added as a solution to the image-receiving sheet coating solution. Or you may add in latex. Alternatively, it may be dissolved in a high boiling point solvent, a low boiling point solvent, or a mixed solvent of both, and then emulsified and dispersed in the presence of a surfactant and added to the latex.

  The coating amount of the receptor layer is preferably from 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). The thickness of the receiving layer is preferably 1 to 20 μm.

(Insulation layer)
The heat insulating layer (porous layer) serves to protect the support from heat during heat transfer using a thermal head. 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 support.

In the image receiving sheet of 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, preferably a polymer latex. For example, 1) water is contained in a partition wall formed of polystyrene, acrylic resin, styrene-acrylic resin, or the like. Non-foamed hollow polymer particles in which the water inside the particles evaporates outside the particles after coating and drying, and the inside of the particles becomes hollow. 2) Low-boiling 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. Foaming type microballoons 3) Microvalves obtained by heating and foaming the above 2) in advance to form a hollow polymer Such as emissions, and the like.

These hollow polymers preferably have an average particle size of 0.1 to 5.0 μm, more preferably 0.2 to 3.0 μm, and particularly preferably 0.3 to 1.0 μm. If this 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 frequency of occurrence of planar failures other than coarse particles in the heat insulating layer increases.
The hollow polymer preferably has a hollow ratio of about 20 to 70%, particularly preferably 20 to 50%. If the hollow ratio is too small, the desired heat insulating property cannot be obtained, and if it is too large, the ratio of hollow polymer particles and incomplete hollow particles that are easily broken increases, resulting in printing defects and insufficient film strength. .
Two or more types of hollow polymers can be mixed and used as necessary. Specific examples of the above 1) include Ropaque HP 1055 manufactured by Law & Haas Co., Ltd., Boncoat PP-1000 manufactured by Dainippon Ink Co., Ltd., SX866 (B) manufactured by JSR Co., Ltd., and Nippon MH MH5055 manufactured by ZEON Co., Ltd. (all 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., EXPANSEL 461DE, 551DE, and 551DE20 (all trade names) manufactured by Nippon Ferrite Co., Ltd. The hollow polymer used for the heat insulating layer may be made into a latex.

As the hollow polymer used in the present invention, non-foamed hollow polymer particles are preferable, and a hollow polymer having a glass transition temperature higher by 10 ° C. or more than the glass transition temperature of the latex polymer is particularly preferable. When the glass transition temperature is low, hollow polymer particles having a sufficient porosity cannot be obtained after the coating / drying step. More specifically, a hollow polymer having a glass transition temperature of 90 ° C. or higher is more preferable, and a polymer having a glass transition temperature of 110 ° C. or higher (preferably 200 ° C. or lower) is particularly preferable.
Here, the relationship between the glass transition temperatures of at least one hollow polymer (glass transition temperature Tg2) and the polymer latex (Tg1) for receiving at least one dye in the receiving layer is Tg1 + 10 ≦ Tg2. The case where there is a relationship is preferable in terms of the effect of the present invention.

  The heat insulating layer containing the hollow polymer preferably contains a water-dispersed resin or a water-soluble resin as a binder in addition to the hollow polymer. 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 a butadiene copolymer, a urethane resin, a polyvinylidene chloride resin, a cellulose derivative, casein, starch, and gelatin can be used. These are preferably water-soluble polymers described in the receiving layer. Among these binder resins, gelatin, polyvinyl alcohol, styrene-butadiene copolymer and urethane resin are preferable, and gelatin and polyvinyl alcohol are more preferable. 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 when the solids content of the binder resin is 100 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 decreases, causing problems such as powder falling off during processing or film peeling. Arise.

0.5-14 mass% is preferable, and, as for the quantity which occupies for the coating liquid of the said binder of a heat insulation layer, 1-6 mass% is especially preferable. The coating amount of the hollow polymer in the heat insulating layer is preferably 1 to 100 g / m <2>, more preferably 5 to 20 g / m <2>.
The thickness of the heat insulating layer containing the hollow polymer is preferably 5 to 50 μm, and more preferably 5 to 40 μm.

(Middle layer)
An intermediate layer may be formed between the support and the heat insulating layer. For example, a white background adjusting layer, a charge adjusting layer, an adhesive layer, a primer layer, and an undercoat layer are formed. About these layers, it can be set as the structure similar to what was described, for example in patent 3585599 specification, patent 2925244 specification. In addition, an intermediate layer can be formed between the heat insulating layer and the receiving layer to have a desired function.

(Undercoat layer)
In the present invention, an undercoat layer is preferably formed between the support and the heat insulating layer.
The undercoat layer of the present invention is presumed to play a role of smoothing the unevenness of the support. In the heat-sensitive transfer image-receiving sheet of the present invention, the undercoat layer contains a polymer latex. The undercoat layer can contain a preservative, a surfactant, and other additives.
Preferred embodiments of the polymer latex of the present invention include polymer latexes such as acrylic polymers, polyesters, rubbers (for example, SBR resin), polyurethanes, polyvinyl chlorides, polyvinyl acetates, polyvinylidene chlorides, and polyolefins. Can be preferably used. The polymer latex may be a linear polymer, a branched polymer, a crosslinked polymer, a so-called homopolymer obtained by polymerizing a single monomer, or a copolymer obtained by polymerizing two or more monomers. Good.
The polymer latex of the present invention is preferably any one or any combination of acrylic polymers, rubbers (for example, SBR resin) and polyurethanes, and rubbers (for example, SBR resin) are most preferable.
In the present invention, the lower the viscosity of the undercoat layer, the better. Specifically, as described above, the viscosity at 40 ° C. and 15 ° C. is preferably 200 mPa · s or less, more preferably 150 mPa · s or less, and 120 mPa · s or less. Most preferred. The undercoat layer preferably does not contain raw materials, chemicals and the like that enhance setability in the setting step. Specifically, it is preferable not to add various known gelling agents such as gelatin, pectin, agar, carrageenan, and gellan gum to the undercoat layer coating solution.

(Support)
In the present invention, it is preferable to use a water-resistant support as the support. By using a water-resistant support, it is possible to prevent moisture from being absorbed into the support, and to prevent a change in performance of the receiving layer over time. As the water-resistant support, for example, coated paper or laminated paper can be used. Of these, laminated paper is preferable in terms of surface smoothness. Similar to polyethylene laminated paper (sometimes abbreviated as WP paper) used for photographic paper in the field of silver salt photography, that is, a support mainly composed of cellulose, and at least a receiving layer is applied. A support having a surface coated with a polyolefin resin can be suitably used.

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

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

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

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

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

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

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

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

  The thickness of the support is preferably 25 μm to 300 μm, more preferably 50 μm to 260 μm, and still more preferably 75 μm to 220 μm. Various stiffnesses can be used according to the purpose of the support. As a support for a thermal transfer image-receiving sheet of photographic quality, a support for color silver salt photographic paper is used. Close ones are preferred.

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

(Writing layer / Charge 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.

  In the present invention, the plurality of layers are composed mainly of a resin. The resin for forming each layer is preferably a polymer latex. The solid content weight 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 polymer latex is 5 μm or less, and particularly preferably 1 μm or less. The polymer latex may contain a known additive such as a surfactant, a dispersant, and a binder resin as necessary.

<Example 1>
(Preparation of ink sheet)
A polyester film having a thickness of 4.5 μm (Lumirror, trade name, manufactured by Toray Industries, Inc.) was used as a base film. A heat-resistant slip layer (thickness 1 μm) was formed on the back side of the film, and yellow, magenta and cyan compositions having the following compositions were applied to the surface side in a single color (coating amount 1 g / m ² during dry film formation).
Yellow composition Dye (Macrolex Yellow 6G, trade name, manufactured by Bayer) 5.5 parts by weight Polyvinyl butyral resin 4.5 parts by weight (ESREC BX-1, trade name, manufactured by Sekisui Chemical Co., Ltd.)
Methyl ethyl ketone / toluene (mass ratio 1/1) 90 parts by mass Magenta composition Magenta dye (Disperse Red 60) 5.5 parts by mass Polyvinyl butyral resin 4.5 parts by mass (ESREC BX-1, trade name, Sekisui Chemical Co., Ltd.) Made by Co., Ltd.)
Methyl ethyl ketone / toluene (mass ratio 1/1) 90 parts by mass Cyan composition Cyan dye (Solvent Blue 63) 5.5 parts by mass Polyvinyl butyral resin 4.5 parts by mass (ESREC BX-1, trade name, Sekisui Chemical Co., Ltd.) ) Made)
Methyl ethyl ketone / toluene (mass ratio 1/1) 90 parts by mass (production of protective layer sheet)
A protective layer and an adhesive layer having the following composition were applied to the same polyester film used for preparing the ink sheet. The coating amount at the time of dry film protective layer 1 g / m ^2, and an adhesive layer 0.7 g / m ^2. The adhesive layer was applied on the protective layer after coating and drying.
Protective layer Acrylic resin 20 parts by mass (Dianar BR-80, trade name, manufactured by Mitsubishi Rayon Co., Ltd.)
Methyl ethyl ketone / toluene (mass ratio 1/1) 80 parts by mass adhesive layer polyester resin 30 parts by mass (Byron 220, trade name, manufactured by Toyobo Co., Ltd.)
Methyl ethyl ketone / toluene (mass ratio 1/1) 70 parts by mass

(Preparation of layer-receiving sheet)
(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 (CAT0304L manufactured by NSC Japan) 1.3%, anionic polyacrylamide (DA4104 manufactured by Seiko PMC Co.) 0.15% per pulp, Alkyl ketene dimer (size pine K manufactured by Arakawa Chemical Co., Ltd.) 29%, 0.29% epoxidized behenamide, 0.32% polyamide polyamine epichlorohydrin (Arakawa Chemical Co., Ltd .: Arafix 100) were added, and then 0.12% of an antifoaming agent was added.

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 drying at a setting of cm, 1 g / m ² of polyvinyl alcohol (manufactured by Kuraray Co., Ltd .: KL-118) was applied on both sides of the base paper with a size press and dried, and calendar treatment was performed. The base paper was made with a basis weight of 157 g / m ² to obtain a base paper (base paper) having a thickness of 160 μm.

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, product Name: Irgaphos 168, manufactured by Ciba Specialty Chemicals Co., Ltd., containing 200 ppm) and MFR 4.0 g / 10 min, low density polyethylene having a density of 0.93 g / cm ³ , 75/25 (mass ratio) the resin composition obtained by blending in a proportion of, and coated to a thickness of 21g / m ^2, thereby forming a thermoplastic resin layer having a matte surface (hereinafter, "rear surface of the thermoplastic resin layer surface The thermoplastic resin layer on the back side is further subjected to corona discharge treatment, and then, as an antistatic agent, aluminum oxide (“Alumina Sol 100” manufactured by Nissan Chemical Industries, Ltd.) and silicon dioxide (Nissan Chemical). A dispersion obtained by dispersing “Snowtex O” manufactured by Kogyo Co., Ltd. in water at a mass ratio of 1: 2 was applied so that the dry mass was 0.2 g / m ² . treated MFR 4.0 g / 10 min with 10 wt% of titanium oxide, by using a melt extruder so that the low-density polyethylene having a density of 0.93 g / m ² to 27 g / m ² was coated, made of mirror A thermoplastic resin layer was formed.

(Preparation of emulsions A and B)
(Preparation of Emulsion A)
Emulsified dispersion A was prepared by the following procedure.
Compound 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 dissolved in 250 g of a 20% by weight gelatin aqueous solution containing 1 g of sodium dodecylbenzenesulfonate by a high-speed stirring emulsifier (dissolver). Emulsified and dispersed, and water was added to prepare 380 g of Emulsion A.
Here, the amount of Compound EB-9 added was adjusted to 30 mmol in Emulsion A.

(Preparation of emulsified dispersion B)
High-boiling solvent (Solv-5) 11.0 g, KF-96 (dimethyl silicone manufactured by Shin-Etsu Chemical Co., Ltd.) 9 g, (EB-9) 15.5 g, (KAYARAD DPCA-30 (manufactured by Nippon Kayaku Co., Ltd.)) ) Dissolve in 7.5 g and 20 ml of ethyl acetate, and emulsify and disperse this liquid in 250 g of a 20% by weight gelatin aqueous solution containing 1 g of sodium dodecylbenzenesulfonate with a high-speed stirring emulsifier (dissolver). The emulsion B was adjusted.

(Preparation of thermal transfer image-receiving sheet 101 (comparative example))
After the corona discharge treatment is performed on the surface of the support prepared as described above, a multilayer composition coating composition of the heat insulating layer coating liquid 1 and the receiving layer coating liquid 1 is formed on the support in order from the lower layer simultaneously. Applied. For simultaneous multi-layer coating, the above-described slide coating was used, and after application, the solution was allowed to pass through a cooling zone at 8 ° C. for 5 seconds to eliminate the fluidity of the liquid, and then a dry air of 22 ° C. and 45% RH was applied for 2 minutes. It was performed by spraying on the coated surface and drying. The composition and coating amount of the coating solution used are shown below.

Insulation layer coating solution 1
(composition)
Emulsion A prepared earlier 21 parts by mass Hollow polymer dispersed aqueous solution 48 parts by mass (MH5055 manufactured by Nippon Zeon Co., Ltd.)
10% aqueous gelatin solution 28 parts by weight Water 3 parts by weight Preservative (compound represented by formula PR-1) 0.2 parts by weight Adjust pH to 8 with NaOH (amount of application) 50 ml / m ²
(Coating liquid viscosity) 45cp

Receiving layer coating solution 1
(composition)
Emulsified B prepared earlier 4 parts by weight Polymer latex aqueous solution of vinyl chloride acrylic compound copolymer 53 parts by weight (Nishin Chemical Co., Ltd. Vinibrand 900)
10 parts by mass of polymer latex aqueous solution of vinyl chloride acrylic compound copolymer (Nishin Chemical Co., Ltd. BiniBran 276)
Microcrystalline wax dispersion aqueous solution 6 parts by mass (Nippon Wax Co., Ltd. EMUSTAR-42X)
Water 22 parts by weight Surfactant 1% aqueous solution (BFS-1) 4 parts by weight Matting agent 1 part by weight (Melamine-silica resin, trade name: Optobead 3500M, manufactured by Nissan Chemical Industries, Ltd.)
Preservative (compound represented by Formula PR-1) 0.1 part by mass
Adjust pH to 8 with NaOH (application amount) 18 ml / m ²
(Coating solution viscosity) 7cp

(Preparation of thermal transfer image-receiving sheet 102 (comparative example))
After the corona discharge treatment is applied to the surface of the support prepared as described above, the composition of the undercoat layer coating solution 1, the heat insulating layer coating solution 1, and the receiving layer coating solution 1 is sequentially formed on the support from the lower layer. Multi-layer coatings were applied simultaneously in multiple layers. For simultaneous multi-layer coating, the above-described slide coating was used, and after application, the solution was allowed to pass through a cooling zone at 8 ° C. for 5 seconds to eliminate the fluidity of the liquid, and then a dry air of 22 ° C. and 45% RH was applied for 2 minutes. It was performed by spraying on the coated surface and drying. The composition and coating amount of the undercoat coating solution 1 used are shown below.
Undercoat layer 1 coating liquid (composition)
An aqueous solution obtained by adding 1% sodium dodecylbenzenesulfonate to a 3% gelatin aqueous solution.
Adjust pH to 8 with NaOH (application amount) 11ml / m2

(Preparation of thermal transfer image-receiving sheet 103 (comparative example))
After the corona discharge treatment is performed on the support surface prepared as described above, the undercoat layer coating solution 2, the heat insulation layer coating solution 1, and the receiving layer coating solution 1 are sequentially formed from the lower layer on the support. It applied sequentially. For sequential coating, first, the undercoat layer coating solution 2 was coated on the support, and after the coating, the fluidity of the solution was lost by applying cold air at 8 ° C. for 15 seconds, followed by natural drying. Subsequently, the heat insulating layer coating liquid 1 was applied, and after applying, cold fluid at 8 ° C. was applied for 15 seconds to eliminate the fluidity of the liquid, and then it was naturally dried. Furthermore, after applying the receiving layer coating liquid 1 and applying the cold air of 8 ° C. for 15 seconds after the coating, the fluidity of the liquid is lost, and finally the dry air of 22 ° C. and 45% RH is applied to the coated surface for 2 minutes. This was done by spraying and drying.
The composition and coating amount of the undercoat coating solution 2 used are shown below.
Undercoat layer 2 coating liquid (composition)
Styrene butadiene latex aqueous solution 60 parts by mass (SR103 manufactured by Nippon A & L Co., Ltd.)
Polyvinyl alcohol (PVA) 6% aqueous solution 40 parts by weight Surfactant 1% aqueous solution (BFS-1) 2 parts by weight Adjusting pH to 8 with NaOH (coating amount) 11 ml / m 2

(Preparation of thermal transfer image-receiving sheet 104 (present invention))
After the corona discharge treatment was performed on the support surface prepared as described above, the composition of the undercoat layer coating solution 2, the heat insulating layer coating solution 1, and the receiving layer coating solution 1 was sequentially formed on the support from the lower layer. Multi-layer coatings were applied simultaneously in multiple layers. For simultaneous multi-layer coating, the above-described slide coating was used, and after application, the solution was allowed to pass through a cooling zone at 8 ° C. for 8 seconds to eliminate the fluidity of the liquid, and then dried at 22 ° C. and 45% RH for 2 minutes. It was performed by spraying on the coated surface and drying.

(Preparation of thermal transfer image-receiving sheet 105 (present invention))
In the heat-sensitive transfer image-receiving sheet 104, a heat-sensitive transfer image-receiving sheet 105 was produced in the same manner as the heat-sensitive transfer image-receiving sheet 104 except that the steps after coating were changed. After coating, slide coating was used to apply simultaneous multi-layer coating, and after passing through a cooling zone of 8 ° C for 15 seconds within 5 seconds, the fluidity of the liquid was lost, and then a dry air of 22 ° C and 45% RH was applied. It was performed by spraying on the coated surface for 2 minutes and drying.

(Preparation of thermal transfer image-receiving sheet 106 (present invention))
A thermal transfer image receiving sheet 106 was prepared in the same manner as the thermal transfer image receiving sheet 105 except that the receiving layer coating liquid 2 was used in place of the receiving layer coating liquid 1 in the thermal transfer image receiving sheet 105.
In addition, the receiving layer coating liquid 2 is a polymer latex of vinyl chloride vinyl acetate copolymer (Vinyl Blanc LG) so that the solid content of the polymer latex is the same in place of the vinyl chloride acrylic copolymer latex in the receiving coating liquid 1. -28B modified 1 (manufactured by Nissin Chemical Co., Ltd.)).

(Preparation of thermal transfer image-receiving sheet 107 (present invention))
A thermal transfer image receiving sheet 107 was prepared in the same manner as the thermal transfer image receiving sheet 105 except that the receiving layer coating liquid 3 was used instead of the receiving layer coating liquid 1 in the thermal transfer image receiving sheet 105.
The receiving layer coating solution 2 is a polymer latex of a vinyl chloride vinyl acetate acrylic compound copolymer (instead of the vinyl chloride acrylic copolymer latex in the receiving coating solution 1) so that the solid content of the polymer latex is the same. It was prepared in the same manner as the receiving layer coating solution 1 except that it was replaced with Vinibrand 601 1 (Nisshin Chemical Co., Ltd.).

(Image formation)
The ink sheet and the heat-sensitive transfer image-receiving sheets 101 to 10 7 were processed so as to be loaded, and output in a high-speed print mode using a sublimation thermal transfer printer ASK2000 (manufactured by Fuji Film Co., Ltd.). At this time, the time from the discharge of the first sheet to the discharge of the second sheet was 8 seconds. The output image was a gradation image that changed from white to max gray (solid black).

(Performance evaluation)
The sensitivity was evaluated using a gradation image from white to max gray (solid black). The visual black density was measured with a Photographic Densitometer (manufactured by X-Rite incorporated), and the relative sensitivity was judged according to the following criteria, with the density at the point of the black density 1.0 of the thermal transfer image-receiving sheet 101 being 100.
5: Greater than 110% 4: Greater than 105% to 110% or less 3: Greater than 100% to 105% or less 2: Greater than 95% to 100% or less 1: Greater than 90% to 95% or less

Evaluation of image quality uniformity is based on white and density of around 1.0, especially around density of 0.5 using “a patch image in which 256 gradations from white to the highest density of cyan and magenta are divided into 4 gradations”. The following criteria were used for sensory evaluation. This is because image quality uniformity is easier to judge, especially in low density areas. The sensory evaluation was performed by five people, and the result of the person who was most severely evaluated was used as the evaluation result.
[Evaluation rank]
5: Uniformity of image quality is good and no rough feeling is felt.
4: Image quality non-uniformity is perceived and slightly rough, but there is no problem with the image.
3: Image quality non-uniformity is perceived and slightly worse, but is not noticeable at a density of about 0.5, and there is no problem.
2: Image quality non-uniformity is felt and is not noticeable around a density of 1.0, but is noticeable around a density of 0.5.
1: Image quality non-uniformity is perceived, and both the density of 0.5 and 1.0 are conspicuous and problematic.

Evaluation of the transferability of the protective layer was carried out according to the following criteria using a gradation image of white to max gray (solid black).
5: No protective layer transfer defect is observed in the image, and there is no practical problem.
4: There is a slight transfer defect of the protective layer in the image, but there is no practical problem.
3: In the image, there is a slight transfer defect of the protective layer on the entire surface, which is a practical problem.
2: In the image, there is a slight protective layer transfer failure on the entire surface, and there is a clear protective layer transfer failure in part, which is a problem in practical use.
1: There is a clear transfer defect of the protective layer on the entire surface of the image, which is a practical problem.

From the above results, “a heat-sensitive transfer image-receiving sheet formed on a support in the order of at least an undercoat layer, a heat-insulating layer, and a receiving layer from the support side, the heat-insulating layer containing at least one hollow polymer, Thermal coating, wherein the coating solution of the undercoat layer has a viscosity at 200 ° C. and 15 ° C. of 200 mPa · s or less, and the heat insulating layer, the undercoat layer, and the receiving layer are all coated simultaneously. It was found that the image-receiving sheet has high density printing characteristics and can achieve high image uniformity, and as a surprising effect, the heat-sensitive transfer image-receiving sheet of the present invention has excellent protective layer transferability. This is presumed that the long-term unevenness of the support was smoothed by the undercoat layer and the transferability of the protective layer was improved.
Here, when the image was output, the samples 106 and 107 were at a level that was not problematic with respect to the sample 105, but some noise was heard when the image was output. This is presumed to be abnormal noise generated when the ink sheet and the heat-sensitive transfer image-receiving sheet are separated. Although this abnormal noise does not cause any problem in image quality, it does not exceed the abnormal noise, and the sample 105 is particularly preferable from this viewpoint.

Claims (8)

A thermal transfer image-receiving sheet formed on a support in the order of at least an undercoat layer, a heat insulating layer and a receiving layer from the support side,
The thermal insulation layer comprises at least one hollow polymer;
The viscosity of the coating solution for the undercoat layer at 40 ° C. and 15 ° C. is 200 mPa · s or less,
A heat-sensitive transfer image-receiving sheet, wherein the heat-insulating layer, the undercoat layer, and the receiving layer are all coated simultaneously. The polymer latex contained in the receptor layer is any one or any combination of vinyl chloride / acrylic compound copolymer latex, vinyl chloride / vinyl acetate copolymer latex, vinyl chloride / vinyl acetate / acrylic compound copolymer latex The heat-sensitive transfer image-receiving sheet according to claim 1, wherein   The thermal transfer image-receiving sheet according to claim 1 or 2, wherein the undercoat layer does not contain gelatin.   The thermal transfer image-receiving sheet according to any one of claims 1 to 3, wherein there is a step of less than 15 ° C within 5 sec immediately after coating, and the passing time of the step is 10 sec or more. A thermal transfer image-receiving sheet formed on a support in the order of at least an undercoat layer, a heat insulating layer and a receiving layer from the support side,
The thermal insulation layer comprises at least one hollow polymer;
The viscosity of the coating solution for the undercoat layer at 40 ° C. and 15 ° C. is 200 mPa · s or less,
A method for producing a heat-sensitive transfer image-receiving sheet, wherein the heat-insulating layer, the undercoat layer and the receptor layer are all coated simultaneously. The polymer latex contained in the receptor layer is any one or any combination of vinyl chloride / acrylic compound copolymer latex, vinyl chloride / vinyl acetate copolymer latex, vinyl chloride / vinyl acetate / acrylic compound copolymer latex The method for producing a thermal transfer image-receiving sheet according to claim 5, wherein:   The method for producing a thermal transfer image-receiving sheet according to claim 5 or 6, wherein the undercoat layer does not contain gelatin.   The method for producing a thermal transfer image-receiving sheet according to any one of claims 5 to 7, wherein there is a step of less than 15 ° C within 5 sec immediately after coating, and the passing time of the step is 10 sec or more. .