JP5817394B2 - Thermal transfer image-receiving sheet and method for producing the same - Google Patents

Description

  The present invention relates to a thermal transfer image-receiving sheet and a method for producing the same, and more particularly, a base material, a receiving layer on one side of the base material, and a binder resin, colloidal on the side of the base material opposite to the receiving layer. The present invention relates to a thermal transfer image receiving sheet comprising a silica and a back layer containing a friction modifier, and a method for producing the same.

  Conventionally, various printing methods are known. Among them, the thermal diffusion type transfer method (sublimation type thermal transfer method) uses a sublimation dye as a color material, so that density gradation can be freely adjusted, and intermediate colors and gradations can be adjusted. It has excellent tone reproducibility and can form high-quality images comparable to silver halide photographs.

  This thermal diffusion transfer system is a method in which a thermal transfer ink sheet containing a dye (sublimation dye) and a thermal transfer image receiving sheet are superposed, and then the ink sheet is heated by a thermal head whose heat generation is controlled by an electrical signal. The dye in the ink sheet is transferred to the image receiving sheet to record image information. As such thermal diffusion transfer systems become widespread, the printing speed has been increased, and sufficient color density can be obtained even if the conventional thermal energy is printed using the conventional thermal transfer ink sheet and thermal transfer image receiving sheet. There are problems such as inability to obtain.

  Furthermore, there are various other problems in the thermal diffusion transfer system. For example, due to insufficient releasability of the image receiving sheet, the ink sheet sticks to the receiving layer surface of the image receiving sheet at the time of printing, and when the ink sheet is peeled off from the image receiving layer after printing, generation of peeling sound, Problems such as poor running and occurrence of peeling lines on the image have occurred.

  Further, in image formation using an apparatus provided with a paper feed roller, contact between the recording paper and the inside of the recording apparatus causes back tension in the direction opposite to the transport direction, which may cause transport unevenness. . Such conveyance unevenness causes slip, overlap feed, paper feed failure, and the like, and as a result, a deviation occurs in the paper feed amount of the recording paper and the ink adhesion position, and the image is disturbed. Therefore, in order to improve performance such as transportability, for example, a thermal transfer image receiving sheet having a back layer containing a styrene butadiene rubber having a glass transition temperature of 50 to 90 ° C., polyethylene wax, and an anionic polystyrene resin is provided. It has been proposed (see, for example, Patent Document 1).

  Another problem is that the antistatic property of the surface (receiving layer) of the image receiving sheet is low, and the electrostatic sticking between the printed products causes a deterioration in handling (hereinafter referred to as “separation”). ing. Therefore, in order to improve antistatic properties, it has also been proposed to include specific colloidal silica in the back surface layer (see Patent Documents 2 to 5).

JP 2009-83298 A JP-A-8-62778 JP 2003-63153 A Japanese Patent Laid-Open No. 2004-130753 JP 2007-237639 A JP 2011-104967 A

  As a result of examining the above-mentioned background art, the present inventors have been able to include a specific binder resin and silica particles in the back layer in order to improve backprint suitability and blocking resistance (for example, patents). (See Document 6), and found that the image receiving surface was damaged when the back side of the thermal transfer image receiving sheet and the receiving layer side were rubbed.

  The present invention has been made in view of the above-mentioned background art and newly discovered problems, and its purpose is to improve various performances such as judgment, scratch resistance, backprint suitability, blocking resistance, and friction suitability. Another object is to provide a thermal transfer image receiving sheet and a method for producing the same.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that in a thermal transfer image-receiving sheet having a specific layer structure, a specific binder resin, a specific colloidal silica, and a specific friction modifier are formed on the back layer. It discovered that the said subject could be solved by making it contain. The present invention has been completed based on such findings.

That is, according to one aspect of the present invention,
A substrate;
A receptor layer on one side of the substrate;
On the surface opposite to the receiving layer of the substrate, a back surface layer containing a binder resin, colloidal silica, and a friction modifier,
The binder resin contains a film-forming aid,
The colloidal silica has an average particle size of 20 to 500 nm,
There is provided a thermal transfer image-receiving sheet in which the friction modifier contains silica particles.

  In the embodiment of the present invention, the binder resin preferably contains an emulsion having a glass transition temperature of 70 ° C. or higher.

  In the aspect of the present invention, it is preferable that the film-forming aid contains at least one selected from the group consisting of isopropyl alcohol, 2-butanol, ethyl cellosolve, butyl cellosolve, and polypropylene glycol monomethyl ether.

  In the aspect of this invention, it is preferable that content of this colloidal silica is 100-600 mass% with respect to the total solid content mass of this binder resin.

  In the embodiment of the present invention, the content of the friction modifier is preferably 10 to 50% by mass with respect to the total solid mass of the binder resin.

  In the embodiment of the present invention, the emulsion preferably contains at least one selected from the group consisting of a polyester resin and a polyurethane resin.

  In the embodiment of the present invention, the silica particles preferably have an average particle diameter of 1 to 10 μm.

In the aspect of the present invention, the back layer is preferably formed by an aqueous coating method.

According to another aspect of the invention,
A method for producing a thermal transfer image receiving sheet, comprising: a base material; a receiving layer on one surface of the base material; and a back layer on a surface opposite to the receiving layer of the base material,
Forming the back surface layer using a coating liquid comprising a binder resin, a film-forming aid, colloidal silica having an average particle diameter of 20 to 500 nm, and a friction modifier containing silica particles. A method for producing a thermal transfer image receiving sheet is provided.

  According to the thermal transfer image-receiving sheet of the present invention, it is possible to improve various performances such as separation, scratch resistance, backprint suitability, blocking resistance, and friction suitability.

1 is a schematic cross-sectional view showing an embodiment of a thermal transfer image receiving sheet according to the present invention.

Thermal transfer image-receiving sheet The thermal transfer image-receiving sheet of the present invention comprises a base material, one surface of the base material, a receiving layer, a binder resin, colloidal silica, and a friction modifier on the surface of the base material opposite to the receiving layer. And a back surface layer containing. In a preferred embodiment, the thermal transfer image receiving sheet may further have a hollow layer or a primer layer between the substrate and the receiving layer. Hereinafter, the structure of the thermal transfer image receiving sheet of the present invention will be described with reference to the drawings.

  According to one aspect of the present invention, on one surface of the substrate, two hollow layers, a primer layer, and a receiving layer are provided in this order, and the surface of the substrate opposite to the receiving layer. There is provided a thermal transfer image-receiving sheet having a back layer thereon. Specifically, a schematic cross-sectional view of one embodiment of the thermal transfer image receiving sheet according to the present invention is shown in FIG. A thermal transfer image receiving sheet 10 shown in FIG. 1 includes a base material 11, a hollow layer A (lower layer) 12, a hollow layer B (upper layer) 13, a primer layer 14, and a receiving surface on one surface of the base material 11. The layer 15 is provided in this order, and the back layer 16 is provided on the surface of the substrate opposite to the receiving layer. Hereinafter, each layer constituting the thermal transfer image receiving sheet of the present invention will be described.

Substrate In the present invention, the substrate has a role of holding the receiving layer on one side and the back layer on the other side, and heat is applied at the time of thermal transfer. A material having a certain level of mechanical strength is preferred.

  Examples of the base material include condenser paper, glassine paper, sulfuric acid paper, high-size paper, synthetic paper (polyolefin-based, polystyrene-based), high-quality paper, art paper, coated paper, and resin-coated paper. , Cast coated paper, wallpaper, backing paper, synthetic resin or emulsion impregnated paper, synthetic rubber latex impregnated paper, synthetic resin internal paper, paperboard, cellulose fiber paper, or polyester, polyacrylate, polycarbonate, polyurethane, polyimide, polyether Imide, cellulose derivative, polyethylene, ethylene-vinyl acetate copolymer, polypropylene, polystyrene, acrylic, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyvinyl butyral, nylon, polyether ether ketone, polysulfone, Examples include polyethersulfone, tetrafluoroethylene, perfluoroalkyl vinyl ether, polyvinyl fluoride, tetrafluoroethylene / ethylene, tetrafluoroethylene / hexafluoropropylene, polychlorotrifluoroethylene, and polyvinylidene fluoride. A white opaque film or a porous film formed by adding a white pigment or a filler to these synthetic resins can also be used, and is not particularly limited. Moreover, the laminated body by the arbitrary combinations of the said base material can also be used. Examples of typical laminates include cellulose fiber paper and synthetic paper, or cellulose fiber paper and plastic film, or a combination of plastic film and synthetic paper. Furthermore, resin-coated paper (RC paper) in which the front and back surfaces of cellulose fiber paper are coated with polyethylene or polypropylene resin can be used. In the present invention, a commercially available base material can be used, and for example, RC paper for photography manufactured by Mitsubishi Paper Industries Co., Ltd. is preferable. The base material thickness can be appropriately changed according to the strength and heat resistance required for the thermal transfer image-receiving sheet and the material of the material employed as the base material. Specifically, the base material thickness is 50 μm. It is preferable to be within a range of ˜1000 μm, and it is more preferable to be within a range of 100 μm to 300 μm.

Back layer The back layer in the present invention has the fixability of ink used in an ink jet method, a dot impact method, a writing instrument, and the like, and enables a back print excellent in quick-drying with less bleeding of the recording portion ( To improve the backprint suitability). Furthermore, it also has the basic characteristics as the image receiving paper back side described below.
1. When superposed on the receiving layer surface, no sticking (blocking) occurs even if it is stored under a temperature or load.
2. Even if it rubs against the receiving layer surface, the receiving layer surface is not damaged, and the particle component does not fall off (powder off) from the back layer.
The back layer contains a binder resin, colloidal silica, and a friction modifier, and other additives such as an antifoaming agent and an antistatic agent can be appropriately added to the back layer. In recent years, a water-based coating method is preferred from the viewpoint of environmental considerations, but the back layer of the present invention can be particularly suitably used as the back surface of an image receiving paper on which a receiving layer is formed by a water-based coating method.

  Colloidal silica contained in the back layer is a colloid composed of fine particles of inorganic oxide containing silicon having an average particle size of several hundred nm or less. Colloidal silica contains silicon dioxide (including its hydrate) as a main component, and may contain aluminate as a minor component. Examples of the aluminate that may be contained as a minor component include sodium aluminate and potassium aluminate. In addition, colloidal silica may contain inorganic salts such as sodium hydroxide, potassium hydroxide, lithium hydroxide and ammonium hydroxide, and organic salts such as tetramethylammonium hydroxide. These inorganic salts and organic salts act, for example, as colloid stabilizers.

  There is no restriction | limiting in particular as a dispersion medium of colloidal silica, Any of water, an organic solvent, and these mixtures may be sufficient. The organic solvent may be a water-soluble organic solvent or a water-insoluble organic solvent, but is preferably a water-soluble organic solvent. Specifically, methanol, ethanol, isopropyl alcohol, n-propanol etc. can be mentioned. Those dispersed in water are called aqueous sols, and those dispersed in organic solvents are called organosols.

  There is no restriction | limiting in particular in the manufacturing method of colloidal silica, It can manufacture by the method used normally. For example, it can be produced from aerosil synthesis by thermal decomposition of silicon tetrachloride or water glass. Alternatively, it can also be produced by a liquid phase synthesis method such as hydrolysis of alkoxide.

  The average particle diameter of the colloidal silica in the present invention is 20 to 500 nm, preferably 20 to 250 nm, more preferably 20 to 150 nm. When the average particle diameter is in the above range, colloidal silica is likely to protrude on the surface of the formed back surface layer, and excellent effects such as blocking resistance, friction characteristics, and charging characteristics possessed by colloidal silica can be exhibited. If the average particle diameter is 500 nm or less, the colloidal silica can be prevented from being lost from the coating film, although it depends on the thickness of the dried coating film and the blending amount of the colloidal silica. Moreover, it is preferable that a back surface layer contains at least 2 types of colloidal silica from which an average particle diameter differs. By including at least two kinds of colloidal silicas having different average particle diameters, it is possible to appropriately fill the gaps formed between the large particle diameter colloidal silicas, and to strengthen the formed coating film, It is also preferable in terms of anti-powder resistance.

  In the present invention, the average particle diameter of colloidal silica can be measured by a conventionally known method such as a BET method, a Sears method, a centrifugal sedimentation method, a dynamic light scattering method, or a laser diffraction method. For example, when the colloidal silica particles are spherical and the particle size is 10 nm or less, the Sears method is used. When the particles are spherical and the particle size is 5 to 100 nm, the BET method is used. When the particles are spherical and the particle size is 70 to 500 nm, centrifugation is performed. In the sedimentation method, when the particles are chain-like and the particle size is 40 to 300 nm, the measurement can be performed by the dynamic light scattering method.

  The content of colloidal silica in the back layer is preferably 100 to 600% by mass, more preferably 150 to 500% by mass, and still more preferably 200 to 300% with respect to the total solid mass of the binder resin. is there. When the content of colloidal silica is 100% by mass or more, it is possible to sufficiently ensure friction characteristics, scratch resistance, suitability for backprinting, and blocking resistance. Moreover, if it is 600 mass% or less, anti-powder resistance can be satisfied.

  In the present invention, commercially available colloidal silica can also be used, Adelite AT-50 (manufactured by ADEKA), Snowtex 50, Snowtex PS-S, Snowtex PS-M, Snowtex UP, Snowtex CM , Snowtex ZL, Snowtex MP-2040, Snowtex MP-1040, Snowtex 20L (manufactured by Nissan Chemical Industries, Ltd.) are preferred.

  The binder resin contained in the back layer preferably contains an emulsion having a glass transition temperature of 70 ° C. or higher. By using an emulsion having a glass transition temperature of 70 ° C. or higher, the dried coating film does not form a film completely, and the emulsion particles are in a clustered state, making it easy to absorb the backprint ink and being hard like silica particles. There is no damage to the receiving layer. Moreover, blocking resistance is not impaired by Tg being 70 degreeC or more. The glass transition temperature can be measured by a conventionally known method such as differential scanning calorimetry (DSC method) or dynamic viscoelasticity measurement method (DMA method).

  The emulsion having a glass transition temperature of 70 ° C. or higher preferably contains at least one selected from the group consisting of polyester resins, polyurethane resins, and acrylic / styrene resins. By using such a binder resin, it is possible to have good adhesion to the base material and good backprint suitability. Furthermore, it is also preferable in terms of dispersibility (charging characteristics), and it is particularly preferable that the receiving layer is a vinyl chloride resin. In the present invention, commercially available binder resins can also be used, such as Bironal MD1500 (manufactured by Toyobo Co., Ltd.), Plus Coat Z690 (manufactured by Kyoyo Chemical Co., Ltd.), Superflex 130 (Daiichi Kogyo Seiyaku Co., Ltd.) And the like are preferable.

  In the present invention, the back surface layer coating solution is prepared as an ink containing a binder resin and a film-forming aid. The film-forming aids include isopropyl alcohol, 2-butanol, methyl cellosolve, ethyl cellosolve, butyl cellosolve, butyl cellosolve and other cellosolves, carbitol (diethylene glycol monoalkyl ether), solfit, polypropylene glycol monomethyl ether, propylene glycol monoethyl Those containing at least one selected from the group consisting of ether acetate, texanol, and N-methyl-2-pyrrolidone are preferred. By using a binder resin and a film-forming aid in combination, a binder resin having a high glass transition temperature (eg, 70 ° C. or higher) with good blocking resistance is used without being mixed with a water-soluble resin or a resin having a low glass transition temperature. can do. In addition, the film-forming aid remaining in the back layer also functions as a compatibilizer with the backprint ink, and can improve the backprint suitability and the like.

  The friction modifier contained in the back layer contains silica particles. Silica particles having an average particle diameter of 1 to 10 μm are preferable. The average particle diameter of silica can be measured by a conventionally known method such as a coal counter method. If the average particle size is in the above range, blocking and powder falling can be prevented, and good backprint suitability can be imparted. The content of the friction modifier in the back layer is preferably 20% by mass or less, more preferably 0.5 to 20% by mass, and still more preferably based on the total solid mass of the binder resin. It is 0.5-10 mass%, Most preferably, it is 1-5 mass%. When the content of the friction modifier is about the above range, the scratching property of the receiving layer can be suppressed, and the friction coefficient of the back layer can be adjusted appropriately. In addition, the backprint suitability and anti-blocking property can be improved.

  In the present invention, commercially available silica particles can also be used. Sicilia 380 (manufactured by Fuji Silysia Chemical Ltd.), NIPGEL AY-200, NIPGEL CX-400, NIPGEL CX-200, NIPGEL AZ-6A0, NIPGEL AY- 451, NIPGEL BY-601 (above, manufactured by Tosoh Silica Co., Ltd.) and the like are preferable.

In the present invention, but are not coating amount of the back layer is particularly limited, it is preferable that the coating amount is in the range of drying after ^{0.2g / m 2 ~3.0g / m 2} , 0.5g / More preferably, it is in the range of m ^{2 to} 1.5 g / m ² . If the coating amount is in the above range, sufficient back print suitability can be obtained.

Receiving layer The receiving layer in the present invention receives the sublimation dye transferred from the thermal transfer ink sheet during image formation by thermal transfer, and holds the received sublimation dye in the receiving layer, whereby an image is formed on the surface of the receiving layer. Can be formed and maintained. The receiving layer is preferably formed by a water-based coating method, and its constituent components are not particularly limited. According to a preferred embodiment, the receiving layer can contain a binder resin, a release agent and the like according to various purposes. Further, the receiving layer may be composed of two or more layers. Resins used for forming the receiving layer include acrylic resins, vinyl chloride resins, polyolefin resins such as polyethylene and polypropylene, polyvinyl chloride / acrylic copolymers, vinyl chloride / vinyl acetate copolymers (vinyl chloride-based). Resin), halogenated polymers such as polyvinylidene chloride, vinyl polymers such as polyvinyl acetate and polyacrylate, polyester resins such as polyethylene terephthalate and polybutylene terephthalate, polystyrene resins, polyamide resins, ethylene and propylene, etc. Examples thereof include copolymer resins of olefins and other vinyl monomers, cellulose resins such as ionomers and cellulose diacetates, polycarbonates and the like, and mixed systems of these resins. Particularly preferred are vinyl chloride resins.

  Examples of the release agent contained in the receiving layer include silicone oil (including reaction-curable silicone), phosphate ester plasticizers, and fluorine compounds, and silicone oil is particularly preferable. Various silicones such as dimethyl silicone can be used as the silicone oil. Specifically, amino-modified silicone, epoxy-modified silicone, alcohol-modified silicone, vinyl-modified silicone, urethane-modified silicone, polyester-modified silicone, polyether-modified silicone, polyester-modified silicone oil, acrylic-modified silicone, amide-modified silicone, etc. These may be mixed or polymerized using various reactions. Two or more release agents may be mixed and used. By using such a release agent, problems such as fusion between the thermal transfer ink sheet and the receiving layer of the thermal transfer image receiving sheet and a decrease in printing sensitivity during printing can be improved. In the present invention, it is particularly preferable to use a release agent in which the modified silicone is dispersed in water. Two or more kinds of water-dispersed release agents of modified silicone may be used, or may be used in combination with other release agents. In the present invention, a commercially available release agent may be used, and X22-3000T (manufactured by Shin-Etsu Chemical Co., Ltd.) or the like may be used after being dispersed in water. Use of such an epoxy-modified silicone is preferable from the viewpoint of combination with the binder resin.

Other Layers The thermal transfer image receiving sheet of the present invention may further have other layers other than the above layers. In a preferred embodiment, the thermal transfer image-receiving sheet can further have other layers such as a hollow layer, a primer layer, an intermediate layer, and a release layer on the receiving layer side.

Hollow layer The hollow layer in the present invention has a heat insulating property that can prevent heat applied during image formation by thermal transfer from being lost due to heat transfer to a substrate or the like. In a preferred embodiment, the hollow layer contains hollow particles and may further contain a hydrophilic binder and other additives. According to a preferred embodiment, the hollow layer may be composed of two or more layers. A hollow layer is provided with cushioning properties by including hollow particles. Here, the degree of cushioning property of the hollow layer can be appropriately adjusted according to the application of the thermal transfer image receiving sheet. The degree of cushioning property of the hollow layer can also be adjusted to an arbitrary range by changing the thickness of the hollow layer, for example. The thickness of the hollow layer is not particularly limited as long as the heat insulating property, cushioning property and the like can be adjusted to a desired level, but preferably in the range of 10 μm to 100 μm, and in the range of 10 μm to 50 μm. More preferably, it is within. The density of the hollow layer, for example in the range of ^{0.1g / cm 3 ~0.8g / cm 3} , preferably in the range of inter alia ^{0.2g / cm 3 ~0.7g / cm 3} .

  The average particle diameter of the hollow particles used in the present invention is preferably 0.1 to 10 μm, more preferably 0.3 to 5 μm. If the average particle diameter of the hollow particles is in the above range, heat insulation and cushioning properties can be imparted to the hollow layer. This is because if the average particle size is too small, the amount of hollow particles used increases and the cost increases, and if the average particle size is too large, it becomes difficult to form a smooth hollow layer. The average hollowness of the hollow particles is preferably 20% or more, more preferably 30 to 80%. If the average hollowness of the hollow particles is in the above range, heat insulation and cushioning properties can be imparted to the hollow layer. Furthermore, the organic hollow particle comprised from resin etc. may be sufficient, and the inorganic hollow particle comprised from glass etc. may be sufficient. The hollow particles may be cross-linked hollow particles. In the present invention, commercially available hollow particles can also be used. For example, Ropeke HP-1055, Ropeke HP-91, Ropeke OP-84J, Ropeke Ultra and Ropeke SE (manufactured by Rohm and Haas Co., Ltd.), Nipol MH-5055 (Nippon Zeon Corporation), SX8782 and SX866 (JSR Corporation) are preferred.

Primer layer The primer layer in the present invention has a role of satisfactorily adhering the hollow layer and the receiving layer, and prevents image migration to the hollow layer side in a high-temperature and high-humidity environment, thereby improving image storage stability. It has a function. In a preferred embodiment, the primer layer contains hollow particles, a resin, and a hydrophilic binder, and the resin preferably contains an acrylic resin. Although it does not specifically limit as thickness of a primer layer, For example, it is preferable that they are 1 micrometer-40 micrometers, 1 micrometer-20 micrometers are more preferable, and 1 micrometer-10 micrometers are more preferable.

  In the present invention, the acrylic resin refers to a polymer of acrylic acid or methacrylic acid monomer or derivative thereof, a polymer of acrylic acid ester or methacrylic acid ester monomer or derivative thereof, acrylic acid or methacrylic acid monomer and other derivatives. It includes a copolymer with a monomer or a derivative thereof, and a copolymer of a monomer of an acrylate ester or a methacrylate ester with another monomer or a derivative thereof.

  According to a preferred embodiment of the present invention, the acrylic resin is preferably a copolymer of an acrylic ester or methacrylic ester monomer and another monomer or a derivative thereof. Examples of the acrylic acid ester or methacrylic acid ester monomer include alkyl acrylate and alkyl methacrylate, preferably methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, lauryl acrylate, and lauryl methacrylate. Can be mentioned. Examples of other monomers include aromatic hydrocarbons, aryl group-containing compounds, amide group-containing compounds, and vinyl chloride, preferably styrene, benzylstyrene, phenoxyethyl methacrylate, acrylamide, and methacrylamide. it can. In the present invention, a copolymer of an alkyl acrylate or an alkyl methacrylate and at least one other monomer selected from the group consisting of an aromatic hydrocarbon, an aryl group-containing compound, and an amide group-containing compound, or a derivative thereof. It is particularly preferable to use it. By copolymerizing the monomers as described above, the concentration and releasability can be improved. Two or more acrylic resins may be mixed and used.

  According to a preferred embodiment of the present invention, the hydrophilic binder contained in the hollow layer or primer layer described above includes gelatin and derivatives thereof, polyvinyl alcohol, polyethylene oxyside, polyvinyl pyrrolidone, pullulan, carboxymethyl cellulose, hydroxyethyl cellulose, Examples include dextran, dextrin, polyacrylic acid and salts thereof, agar, κ-carrageenan, λ-carrageenan, ι-carrageenan, casein, xanthene gum, locust bean gum, alginic acid, and gum arabic, with gelatin being particularly preferred. By using such a hydrophilic binder, interlayer adhesion of each layer can be improved. In particular, when each layer is formed by an aqueous coating method and a simultaneous multilayer coating method, by using gelatin, the viscosity of each coating solution can be adjusted to a desired range, and a desired film thickness can be obtained. In the present invention, commercially available gelatin can also be used. For example, RR, R, CLV, G1236 (manufactured by Nitta Gelatin Co., Ltd.) and the like are preferable.

Intermediate Layer In the present invention, at least one intermediate layer may be provided between the hollow layer and the primer layer or between the primer layer and the receiving layer. By providing an intermediate layer, functions such as solvent resistance, dye diffusion barrier during image storage under high temperature / high humidity, interlayer adhesion, white color imparting, glare / unevenness of the substrate, and antistatic functions are added. Can do. As a method for forming the intermediate layer, known means can be used. For example, an optical brightener, inorganic fine particles, hollow fine particles, and an organic conductive material such as a conductive filler or polyaniline sulfonic acid are added to the intermediate layer. The method of doing is mentioned.

Release layer In the present invention, the release agent may not be added to the receiving layer, but may be provided as a separate release layer on the receiving layer.

Method for Producing Thermal Transfer Image-Receiving Sheet A method for producing a thermal transfer image-receiving sheet according to the present invention comprises a base material, a receiving layer on one surface of the base material, and a back layer on the surface opposite to the receiving layer of the base material. A method for producing a thermal transfer image-receiving sheet, the back layer comprising a binder resin, a film-forming aid, colloidal silica having an average particle diameter of 20 to 500 nm, and a friction modifier comprising silica particles The process of forming using the coating liquid containing these is included. For the application of each layer of the thermal transfer image-receiving sheet, known methods such as roll coating, bar coating, gravure coating, gravure reverse coating, die coating, slide coating, and curtain coating can be used. A method in which a plurality of layers such as a slide coat and a curtain coat can be applied simultaneously in multiple layers is preferred. In the present invention, it is preferable to form all the layers constituting the receiving layer from the hollow layer on the side having the receiving layer by an aqueous coating method and a simultaneous multilayer coating method. By such a manufacturing method, effects such as improvement in interlayer adhesion of each layer of the thermal transfer image-receiving sheet and cost improvement can be obtained.

  In the present invention, when the back surface layer is formed by aqueous coating, the back surface layer coating solution is used in combination with a binder resin and a film-forming aid, and is dried at, for example, 50 ° C. or more, preferably 80 ° C. to 150 ° C. Thus, productivity can be improved and an appropriate film-forming state can be formed, so that adhesion, blocking resistance, and backprint suitability are improved.

Thermal transfer ink sheet The thermal transfer ink sheet used together with the thermal transfer image-receiving sheet of the present invention is provided with a heat transferable color material layer on one side of the base sheet and a heat resistant slipping layer on the other side of the base sheet. It is preferable to have a layer structure. Hereinafter, each layer constituting the thermal transfer ink sheet will be described.

As the material of the base sheet constituting the thermal transfer ink sheet used in the present invention, a conventionally known material can be used, and even if it is other than that, it has a certain degree of heat resistance and strength. Can be used. For example, polyethylene terephthalate, polyester, polypropylene, polycarbonate, polyethylene, polystyrene, polyvinyl alcohol, polyvinyl chloride, polyvinylidene chloride, polyimide, nylon, cellulose acetate, ionomer and other resin films, condenser paper, paraffin paper, and other non-woven fabrics Etc. These may be used alone, or a laminate in which these are arbitrarily combined may be used. Among these, polyethylene terephthalate which is a versatile plastic that can be thinned and is inexpensive is preferable.

  The thickness of the base sheet can be appropriately selected according to the material so that the strength, heat resistance and the like are appropriate, but is usually preferably about 0.5 to 50 μm, more preferably 1 to 20 μm, and further Preferably it is 1-10 micrometers.

  The base sheet may be subjected to a surface treatment in order to improve adhesion with an adjacent layer. As the surface treatment, known resin surface modification techniques such as corona discharge treatment, flame treatment, ozone treatment, ultraviolet treatment, radiation treatment, surface roughening treatment, chemical treatment, plasma treatment, and grafting treatment are applied. can do. Only one type of the surface treatment may be applied, or two or more types may be applied.

  Furthermore, it is also possible to apply and form an adhesive layer on the base sheet as an adhesive treatment of the base sheet. An adhesion layer can be formed from the following organic materials and inorganic materials, for example. Examples of the organic material include polyester resins, polyacrylate resins, polyvinyl acetate resins, polyurethane resins, styrene acrylate resins, polyacrylamide resins, polyamide resins, polyether resins, polystyrene resins, Examples thereof include polyethylene resins, polypropylene resins, polyvinyl chloride resins, polyvinyl alcohol resins, polyvinyl pyrrolidone and vinyl resins such as modified products thereof, and polyvinyl acetal resins such as polyvinyl acetoacetal and polyvinyl butyral. Examples of the inorganic material include silica (colloidal silica), alumina or alumina hydrate (alumina sol, colloidal alumina, cationic aluminum oxide or hydrate, suspicion bakumaite, etc.), aluminum silicate, magnesium silicate, magnesium carbonate, oxidation Examples thereof include ultrafine particles of colloidal inorganic pigments such as magnesium and titanium oxide.

  Moreover, when manufacturing a plastic film by extending | stretching as said surface treatment, a primer liquid can be apply | coated to an unstretched film and it can also carry out by extending | stretching after that (primer process).

Thermal transferable color material layer The thermal transfer ink sheet used in the present invention is provided with a thermal transferable color material layer on one surface of a substrate sheet. When the thermal transfer ink sheet is a sublimation type thermal transfer ink sheet, a layer containing a sublimation dye is formed as the thermal transferable color material layer, and when the thermal transfer type thermal transfer ink sheet is a hot melt composition containing a colorant A layer containing a heat-meltable ink is formed. A layer region containing a sublimable dye and a layer region containing a heat-meltable ink composed of a heat-melting composition containing a colorant are provided in a surface sequence on a continuous base sheet. Also good.

  As the material of the heat transferable color material layer, conventionally known dyes can be used, but those having good characteristics as a printing material, for example, having a sufficient coloring density and changing color due to light, heat, temperature, etc. Those that do not are preferred. For example, as a red dye, MS Red G (manufactured by Mitsui Toatsu Chemical Co., Ltd.), Macrolex Red Violet R (manufactured by Bayer), CeresRed 7B (manufactured by Bayer), Samalon Red F3BS (manufactured by Mitsubishi Chemical), etc. are yellow. Examples of the dye include Holon Brilliant Yellow 6GL (manufactured by Clariant), PTY-52 (manufactured by Mitsubishi Kasei Co., Ltd.), Macrolex Yellow 6G (manufactured by Bayer), etc., and examples of the blue dye include Kayaset Blue 714 (Nippon Kayaku Co., Ltd.). Manufactured), Waxoline Blue AP-FW (manufactured by ICI), Holon Brilliant Blue SR (manufactured by Sand), MS Blue 100 (manufactured by Mitsui Toatsu Chemicals) and the like.

  Examples of the binder resin for supporting the dye include cellulose resins such as ethyl cellulose resin, hydroxyethyl cellulose resin, ethyl hydroxy cellulose resin, methyl cellulose resin, and cellulose acetate resin, polyvinyl alcohol resin, polyvinyl acetate resin, and polyvinyl butyral resin. And vinyl resins such as polyvinyl acetal resin and polyvinyl pyrrolidone, acrylic resins such as poly (meth) acrylate and poly (meth) acrylamide, polyurethane resins, polyamide resins, and polyester resins. Among these, cellulose-based, vinyl-based, acrylic-based, polyurethane-based, and polyester-based resins are preferable from the viewpoints of heat resistance, dye transferability, and the like.

  Examples of the method for forming the heat transferable color material layer include the following methods. For the heat-transferable colorant layer obtained by adding additives such as a release agent to the above dyes and binder resin, if necessary, dissolved in an appropriate organic solvent such as toluene or methyl ethyl ketone, or dispersed in water. A coating solution (dissolved solution or dispersion) is applied to one surface of a substrate sheet by, for example, a gravure printing method, a reverse roll coating method using a gravure plate, a roll coater, a bar coater, etc., and dried. Can be formed. The heat transferable color material layer has a thickness of about 0.2 to 5.0 μm, and the content of the sublimable dye in the heat transferable color material layer is 5 to 90% by mass, preferably 5 to 70% by mass. It is preferable that

Protective layer The thermal transfer ink sheet used in the present invention may be provided with a protective layer in the surface order on the same side as the thermal transferable color material layer. After the color material is transferred to the thermal transfer image-receiving sheet, the protective layer is transferred to cover the image, whereby the image can be protected from light, gas, liquid, abrasion and the like. Other layers such as an adhesive layer, a release layer, a release layer, or an undercoat layer may be provided as a protective layer.

Heat-resistant slip layer The heat-resistant slip layer is mainly composed of a heat-resistant resin. The heat resistant resin is not particularly limited. For example, polyvinyl butyral resin, polyvinyl acetoacetal resin, polyester resin, vinyl chloride-vinyl acetate copolymer resin, polyether resin, polybutadiene resin, styrene-butadiene copolymer resin, Acrylic polyol, polyurethane acrylate, polyester acrylate, polyether acrylate, epoxy acrylate, urethane or epoxy prepolymer, nitrocellulose resin, cellulose nitrate resin, cellulose acetate propionate resin, cellulose acetate butyrate resin, cellulose acetate-hydrodiene Phthalate resin, cellulose acetate resin, aromatic polyamide resin, polyimide resin, polyamideimide resin, polycarbonate resin, Fine chlorinated polyolefin resins.

  The heat resistant slipping layer may be formed by blending additives such as a slipperiness imparting agent, a crosslinking agent, a release agent, an organic powder, and an inorganic powder in addition to the above heat resistant resin.

  In general, the heat-resistant slipping layer is prepared by adding the above-mentioned heat-resistant resin and the above-mentioned slipperiness-imparting agent and additives that are optionally added to the solvent, and dissolving or dispersing each component to form a heat-resistant slipping layer coating solution. After the preparation, the heat resistant slipping layer coating solution can be applied on a substrate and dried. As the solvent in the heat resistant slipping layer coating solution, the same solvents as those in the dye ink can be used.

Examples of the coating method of the heat resistant slipping layer coating liquid include wire bar coating, gravure printing, screen printing, reverse roll coating using a gravure plate, and gravure coating is particularly preferable. Heat-resistant slip layer coating solution, dry coating amount is preferably 0.1 to 3 g / ^{m 2,} more preferably may be applied so as to be 1.5 g / ^{m 2} or less.

Image Forming Method In the image forming method using the thermal transfer image receiving sheet of the present invention, the thermal transfer image receiving sheet and the thermal transfer ink sheet containing a heat diffusible dye are overlaid and heated in accordance with a recording signal, thereby transferring the thermal transfer image. An image can be formed by transferring the thermal diffusible dye contained in the ink sheet to the thermal transfer image-receiving sheet.

  As a thermal transfer recording apparatus that can be used in such an image forming method, a known apparatus can be used and is not particularly limited. In the present invention, a commercially available thermal transfer recording apparatus can be used, and examples include a sublimation thermal transfer printer (manufactured by ALTECH ADS, model: MEGAPIXEL III).

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. However, the present invention is not limited to the following examples. In addition, the mass part of description described was described by solid content, and it diluted with the pure water as needed.

Example 1
RC paper (manufactured by Mitsubishi Paper Industries Co., Ltd.) is used as a base material for producing the thermal transfer image-receiving sheet 1. It was applied so as to be 0.8 g / m ² and dried at 50 ° C. for 2 minutes. In addition, the coating liquid was appropriately diluted and blended so that no agglomerates were generated when blended, and the total solid content was appropriately selected according to the coating conditions.
Composition of backside layer coating solution 1 Binder resin (polyester resin, emulsion, film-forming auxiliary (n-butyl cellosolve) contained, Tg = 77 ° C. (DSC method), manufactured by Toyobo Co., Ltd., trade name: Bironal MD1500: Solid content 30%) 100 parts by mass Colloidal silica (average particle size: 20-30 nm, manufactured by ADEKA Corporation, trade name: Adelite AT-50: solid content 48%) 188 parts by mass Silica particles (average particle size: 4.0 μm, manufactured by Tosoh Silica Co., Ltd., trade name: NIPEGLCX-400) 3.6 parts by mass / 344 parts by mass of pure water

Subsequently, the coating liquid 1 for the hollow layer A, the coating liquid 1 for the hollow layer B, the coating liquid 1 for the primer layer, and the coating liquid 1 for the receiving layer having the following composition are respectively heated to 40 ° C. Using the coating, the thickness at the time of WET is 15 μm, 25 μm, 15 μm, and 8 μm, respectively, cooled at 5 ° C. for 30 seconds, dried at 50 ° C. for 2 minutes, and heat-transfer image-receiving sheet 1 (layer) Structure: Back layer / base material / hollow layer A / hollow layer B / primer layer / receiving layer) was obtained. The coating speed was 100 m / min. This thermal transfer image-receiving sheet had a layer structure as shown in FIG.
Composition of coating liquid 1 for hollow layer A (for lower layer) Hollow particles (average particle size: 0.5 μm, average hollowness: 45%, manufactured by Rohm and Haas Co., Ltd., trade name: Ropeke Ultra, solid (30%) 276 parts by weight Gelatin (made by Nitta Gelatin Co., Ltd., trade name: G1236K) 27 parts by weight 600 parts by weight pure water Binder resin (styrene / acrylic resin, made by Shin Nakamura Chemical Co., Ltd.) , Trade name: New Coat B-13, solid content: 42%) 32.8 parts by mass / pure water 13.2 parts by weight / binder resin (styrene / acrylic resin, manufactured by BASF Japan Ltd., trade name: John Krill 62J: solid content 34%) 40.6 parts by mass / pure water 14.6 parts by mass
Composition of hollow layer B coating solution 1 (for upper layer) Hollow particles (average particle size: 0.5 μm, average hollowness: 45%, manufactured by Rohm and Haas Co., Ltd., trade name: Ropeke Ultra: solid 447 parts by weight gelatin (Nitta Gelatin Co., Ltd., trade name: G1236K) 40 parts by weight pure water 433 parts by weight binder resin (styrene / acrylic resin, Shin-Nakamura Chemical Co., Ltd.) Product name: New Coat B-13: Solid content 42%) 23.8 parts by mass, 9.5 parts by mass of pure water, binder resin (styrene / acrylic resin, manufactured by BASF Japan Ltd., product name: Jonkrill 62J: Solid content 34%) 47 parts by mass / pure water 17 parts by mass / surfactant (sodium dioctylsulfosuccinate aqueous solution: solid content 20%) 2 parts by mass
Composition of primer layer coating solution 1 Cross-linked hollow particles (average particle size: 0.1 μm, average hollow ratio: 30%, manufactured by JSR Corporation, trade name: SX866, solid content: 20%) 658 parts by mass Gelatin (Product name: G1236K, manufactured by Nitta Gelatin Co., Ltd.) 44 parts by mass, 422 parts by mass of pure water, binder resin (styrene / acrylic resin, manufactured by BASF Japan Ltd., product name: Jonkrill 62J: solid content 34% ) 17.7 parts by mass / pure water 6.4 parts by mass / binder resin (modified rubber, manufactured by Resex Corp., trade name MG-67: solid content 51%) 18.6 parts by mass / surfactant (dioctylsulfosucci) Sodium acid aqueous solution: solid content 20%) 2 parts by mass
Composition of coating solution 1 for receiving layer / vinyl acetate resin latex (vinyl chloride / vinyl acetate = 97.5 / 2.5): solid content 36%)
411 parts by mass-Aqueous dispersion of release agent (solid content: 17%) 98 parts by mass-Epoxy crosslinking agent (manufactured by Nagase Chemtex Co., Ltd., trade name EX-512: solid content 100%) 7.6 parts by mass -11.4 parts by mass of pure water-Thickener (manufactured by ADEKA, trade name Adecanol UH-526: solid content 30%)
45 parts by mass, 230 parts by mass of pure water, 23 parts by mass of a surfactant (sodium dioctylsulfosuccinate aqueous solution: solid content 20%)

Preparation of vinyl chloride-based emulsion The vinyl chloride- based resin latex used in the receiving layer coating solution 1 was prepared as follows. In a 2.5 L autoclave, 600 g of deionized water, 438.8 g of vinyl chloride monomer (97.5% by mass with respect to all charged monomers) and 11.2 g of vinyl acetate (2% with respect to all charged monomers) .5 mass%) and 2.25 g of potassium persulfate were charged. The reaction mixture was stirred with a stirring blade so as to maintain a rotation speed of 120 rpm, and the temperature of the reaction mixture was raised to 60 ° C. to initiate polymerization. 180 g of a 5% by mass aqueous sodium dodecylbenzenesulfonate solution (2% by mass with respect to all charged monomers) was continuously added until after the start of polymerization until 4 hours, and the saturated vapor pressure of the vinyl chloride monomer at a polymerization pressure of 60 ° C. The polymerization was stopped when the pressure dropped from 0.6 MPa to a residual monomer, and a vinyl acetate resin latex was obtained.

Preparation of Release Agent Aqueous Dispersion The release agent aqueous dispersion used in the receiving layer coating solution 1 was prepared as follows. 16 g of epoxy-modified silicone (trade name X-22-3000T manufactured by Shin-Etsu Chemical Co., Ltd.) and 8 g of aralkyl-modified silicone (trade name X-24-510 manufactured by Shin-Etsu Chemical Co., Ltd.) are dissolved in 85 g of ethyl acetate. A solvent-based solution was prepared. Next, 14 g of triisopropyl naphthalene sulfonic acid sodium salt (solid content: 10%) was dissolved in 110 g of pure water to prepare an aqueous solution. Subsequently, the solvent-based solution and the aqueous solution were mixed and stirred, and then dispersed using a homogenizer to prepare a dispersion. Thereafter, ethyl acetate was removed under reduced pressure while heating the dispersion to 30 to 60 ° C. to obtain an aqueous dispersion of silicone.

Example 2
Preparation of thermal transfer image-receiving sheet 2 A thermal transfer image-receiving sheet 3 was prepared in the same manner as in Example 1 except that the composition of the coating solution for the back surface layer was as follows.
Composition of back surface coating solution 2 -Binder resin (polyester resin, emulsion, film-forming auxiliary (t-butyl cellosolve) included, Tg = 110 ° C (DSC method), manufactured by Kyoyo Chemical Industry Co., Ltd., trade name: Plus Coat Z690: Solid content 25%) 100 parts by mass, colloidal silica (average particle size: 20-30 nm, manufactured by ADEKA, trade name: Adelite AT-50: solid content 48%) 156 parts by mass, silica particles (average particle Diameter: 4.0 μm, manufactured by Tosoh Silica Co., Ltd., trade name: NIPGEL CX-400) 3 parts by mass / 256 parts by mass of pure water

Example 3
Preparation of thermal transfer image receiving sheet 3 A thermal transfer image receiving sheet 3 was prepared in the same manner as in Example 1 except that the composition of the coating solution for the back surface layer was as follows.
Composition of back surface coating solution 3 Binder resin (polyurethane resin, emulsion, film-forming auxiliary (N-methyl-2-pyrrolidone) contained, Tg = 101 ° C. (dynamic viscoelasticity measuring method), Daiichi Kogyo Seiyaku ( Co., Ltd., trade name: Superflex 130: solid content 30%) 100 parts by mass, colloidal silica (average particle size: 20-30 nm, manufactured by ADEKA, trade name: Adelite AT-50: solid content 48%) 188 parts by mass / silica particles (average particle size: 4.0 μm, manufactured by Tosoh Silica Co., Ltd., trade name: NIPGEL CX-400) 3.6 parts by mass / 344 parts by mass of pure water

Comparative Example 1
Preparation of thermal transfer image-receiving sheet 4 A thermal transfer image-receiving sheet 4 was prepared in the same manner as in Example 1 except that the composition of the coating solution for the back surface layer was as follows.
Composition of back surface coating solution 4 Binder resin (acrylic / styrene resin, no film-forming auxiliary, emulsion, Tg = 11 ° C., manufactured by Rohm & Haas Co., Ltd., trade name: Lucidene 606APEF: solid content 47%) 53 parts by mass binder resin (acrylic / styrene resin, no film-forming auxiliary, emulsion, Tg = 100 ° C., manufactured by Rohm and Haas Co., Ltd., trade name: Luciden 375CI solid content 46%) 54 parts by mass / alumina (average particle size: 1 μm (laser diffraction method), manufactured by Sumitomo Chemical Co., Ltd., trade name: AM-27) 37.5 parts by mass / pure water 293 parts by mass

Comparative Example 2
Preparation of thermal transfer image-receiving sheet 5 A thermal transfer image-receiving sheet 5 was prepared in the same manner as in Example 1 except that the composition of the coating solution for the back layer was as follows.
Composition of back surface coating solution 5 Binder resin (acrylic / styrene resin, no film-forming auxiliary, emulsion, Tg = 11 ° C., manufactured by Rohm & Haas Co., Ltd., trade name: Lucidene 606APEF: solid content 47%) 53 parts by mass binder resin (acrylic / styrene resin, no film-forming auxiliary, emulsion, Tg = 100 ° C., manufactured by Rohm and Haas Co., Ltd., trade name: Luciden 375CI solid content 46%) 54 parts by mass / silica particles (average particle size: 4.0 μm, manufactured by Tosoh Silica Co., Ltd., trade name: NIPGEL CX-400) 37.5 parts by mass / pure water 293 parts by mass

Comparative Example 3
Preparation of thermal transfer image receiving sheet 6 A thermal transfer image receiving sheet 6 was prepared in the same manner as in Example 1 except that the composition of the coating solution for the back surface layer was as follows.
Composition of back surface coating solution 6 Binder resin (acrylic / styrene resin, no film-forming auxiliary, emulsion, Tg = 11 ° C., manufactured by Rohm & Haas Co., Ltd., trade name: Lucidene 606APEF: solid content 47%) 53 parts by mass binder resin (acrylic / styrene resin, no film-forming auxiliary, emulsion, Tg = 100 ° C., manufactured by Rohm and Haas Co., Ltd., trade name: Luciden 375CI solid content 46%) 54 parts by mass / silica particles (average particle size 9.0 μm, manufactured by Fuji Silysia Chemical Ltd., trade name: Cicilia 380) 37.5 parts by mass / pure water 293 parts by mass

Comparative Example 4
Thermal transfer image-receiving sheet 7 Preparation A thermal transfer image-receiving sheet 7 was prepared in the same manner as in Example 1 except that the composition of the coating solution for the back layer was as follows.
Composition of backside layer coating solution 7 Binder resin (acrylic / styrene resin, no film-forming aid contained, emulsion, Tg = 11 ° C., manufactured by Rohm & Haas Co., Ltd., trade name: Lucidene 606APEF: solid content 47%) 106 parts by mass Binder resin (acrylic / styrene resin, no film-forming auxiliary, emulsion, Tg = 100 ° C., manufactured by Rohm & Haas Co., Ltd., trade name: Lucidene 375CI solid content 46%) 109 parts by mass, 285 parts by mass of pure water

Evaluation of Thermal Transfer Image Receiving Sheets Regarding the thermal transfer image receiving sheets 1 to 7 prepared above, (1) evaluation for evaluation of wiping, (2) evaluation of scratch resistance, (3) evaluation of suitability for backprint, (4) evaluation of blocking resistance, and (5 ) The friction suitability was evaluated.

(1) Evaluation of judgment property Using the thermal transfer image-receiving sheet prepared above, 100 natural images were printed with the sublimation transfer printing system “Print Center (DNP Photolcio Co., Ltd.)”, and the prints were prepared. Evaluated for ease / Evaluation Criteria A : Can be easily aligned and has good judgment.
(Triangle | delta): It can arrange, and the judgment property was normal.
X: It was not able to arrange, and the judgment property was unsatisfactory.

(2) Scratch resistance evaluation About the thermal transfer image receiving sheet prepared above, using the thermal transfer image receiving sheets prepared in the same Example and Comparative Example, the back side of the thermal transfer image receiving sheet and the receiving layer side of the other thermal transfer image receiving sheet And facing each other and visually observing whether or not the surface on the receiving layer side is scratched. The scratch resistance was evaluated according to the following evaluation criteria.
-Evaluation criteria ( circle): The receiving layer surface was not damaged.
Δ: Slight scratches on the receiving layer surface.
×: Many scratches on the receiving layer surface.

(3) Backprint suitability evaluation The back layer of the thermal transfer image-receiving sheet prepared above was subjected to test printing using an impact dot printer iDP3550 (manufactured by Citizen Systems Co., Ltd.) and a dedicated ribbon cassette (black). After the elapse of time, the receiving layer surface on which a Cy solid (tone value 38/255) was printed with a sublimation type thermal transfer printer (ALTECH ADS Co., Ltd., model: MEGAPIXELIII) and a MEGAPIXELIII genuine ribbon was overlapped on the back layer. The film was sandwiched between 125 μm PET films and treated with a laminator (Lami Packer LPD3204, Fuji Plastic Co., Cold mode, speed 2.5) to confirm the presence or absence of transfer to the receiving layer, and evaluated according to the following three criteria. The following results are shown in Table 1. In addition, the thing of evaluation (circle) has the absorptivity and quick-drying property of the ink of the level which is satisfactory practically.
・Evaluation criteria ○: There was no setback to the receiving layer.
Δ: Slight setback to the receiving layer occurred.
X: The setback to the receiving layer was apparently generated.

(4) Evaluation of blocking resistance About the thermal transfer image-receiving sheet prepared above, using the thermal transfer image-receiving sheets produced in the same Example and Comparative Example, the back side of the thermal transfer image-receiving sheet and the receiving layer of the other thermal transfer image-receiving sheet In a state of being sandwiched between 150 μm thick synthetic paper (manufactured by YUPO Corporation, YUPO FPG # 150) with the side facing each other, a load of 20 kg / 105 mm × 148 mm is applied, After being left in an oven at 60 ° C. for 150 hours, the receiving layer surface and the back surface, which had been superposed, were peeled off, and whether or not uneven printing occurred was visually observed, and blocking resistance was evaluated according to the following evaluation criteria. However, after the above load, the printing unevenness was evaluated by printing a test pattern using a thermal transfer printer CP9500D manufactured by Mitsubishi Electric Corporation in combination with a thermal transfer sheet dedicated to the thermal transfer printer CP9500D.
Evaluation criteria ○: No printing unevenness occurred and no blocking occurred.
Δ: Print unevenness was slightly generated and blocking was slightly generated.
X: Printing unevenness occurred and blocking occurred.

(5) Evaluation of friction suitability The friction coefficient with the paper flange of sublimation type thermal transfer printer (manufactured by ALTECH ADS, model: DS40) is compared to the back layer of the thermal transfer image-receiving sheet produced above. (Tensile speed: 500 mm / min, load: 1 kg).
Evaluation criteria ○: Friction coefficient is 0.25 or more Δ: Friction coefficient is 0.2 to 0.25
×: Friction coefficient is 0.2 or less

The results of the above evaluations are shown in Table 1. The thermal transfer image-receiving sheets of Examples 1 to 3 that satisfy the composition of the present invention are superior in the spreadability, scratch resistance, backprint suitability, blocking resistance, and friction suitability as compared with the thermal transfer image-receiving sheets of Comparative Examples 1 to 4. You can see that

10 Thermal transfer image-receiving sheet 11 Base material 12 Hollow layer A (lower layer)
13 Hollow layer B (upper layer)
14 Primer layer 15 Receptor layer 16 Back layer

Claims (7)

A substrate;
A receiving layer on one side of the substrate;
On the surface opposite to the receiving layer of the base material, a back surface layer containing a binder resin, a film-forming aid, colloidal silica, and a friction modifier,
The film-forming aid is isopropyl alcohol, 2-butanol, methyl cellosolve, ethyl cellosolve, butyl cellosolve, butyl cellosolve, diethylene glycol monoalkyl ether, solfit, polypropylene glycol monomethyl ether, propylene glycol monoethyl ether acetate, texanol, and N- Including at least one selected from the group consisting of methyl-2-pyrrolidone,
The colloidal silica has an average particle size of 20 to 500 nm,
The thermal transfer image receiving sheet in which the friction modifier contains silica particles.   The thermal transfer image receiving sheet according to claim 1, wherein the binder resin contains an emulsion having a glass transition temperature of 70 ° C. or higher.   The thermal transfer image-receiving sheet according to claim 1 or 2, wherein a content of the colloidal silica is 100 to 600 mass% with respect to a total solid mass of the binder resin.   The thermal transfer image-receiving sheet according to any one of claims 1 to 3, wherein a content of the friction modifier is 20% by mass or less based on a total solid mass of the back surface layer.   The thermal transfer image-receiving sheet according to any one of claims 2 to 4, wherein the emulsion comprises at least one selected from the group consisting of a polyester resin, a polyurethane resin, and an acrylic / styrene resin.   The thermal transfer image-receiving sheet according to any one of claims 1 to 5, wherein an average particle diameter of the silica particles is 1 to 10 µm. A method for producing a thermal transfer image-receiving sheet, comprising: a base material; a receiving layer on one surface of the base material; and a back layer on a surface opposite to the receiving layer of the base material,
The back layer comprises a binder resin, isopropyl alcohol, 2-butanol, methyl cellosolve, ethyl cellosolve, butyl cellosolve, butyl cellosolve, diethylene glycol monoalkyl ether, solfit, polypropylene glycol monomethyl ether, propylene glycol monoethyl ether acetate, texanol, and It comprises a film-forming aid containing at least one selected from the group consisting of N-methyl-2-pyrrolidone, colloidal silica having an average particle size of 20 to 500 nm, and a friction modifier containing silica particles. A method for producing a thermal transfer image receiving sheet, comprising a step of forming using a coating solution.

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