JP5412920B2 - Thermal transfer image receiving sheet and method for producing thermal transfer image receiving sheet - Google Patents

Description

  The present invention relates to a thermal transfer image receiving sheet and a method for producing a thermal transfer image receiving sheet.

  As a method for forming an image using thermal transfer, a method using thermal transfer with a heating medium such as a thermal head is known. The method includes a thermal transfer sheet in which a sublimation dye as a recording material is supported on a support sheet such as paper or plastic film, and a sublimation dye receiving layer on one side of a base sheet such as paper or plastic film. There is known a method of forming an image by superimposing the provided thermal transfer image receiving sheets on each other, applying heat from the back surface of the thermal transfer sheet with a heating medium, and transferring the sublimation dye to the thermal transfer image receiving sheet.

  In order to easily form a high-quality image on the thermal transfer image-receiving sheet by this method, it is important to provide a thermal transfer image-receiving sheet with high thermal transfer sensitivity and suppressed image defects at low cost.

  In this regard, a heat-sensitive transfer image-receiving sheet formed in the order of at least an undercoat layer, a heat-insulating layer, and a receiving layer from the support side on the support forming the base sheet, wherein the heat-insulating layer contains at least one type of hollow polymer. A thermal transfer image-receiving sheet having a quality layer has been proposed (see Patent Document 1). This thermal transfer image-receiving sheet is formed by simultaneously applying an undercoat layer, a porous layer and a receiving layer. The undercoat layer coating solution used in forming the thermal transfer image-receiving sheet has a predetermined range of viscosity.

  In the heat-sensitive transfer image-receiving sheet described in Patent Document 1, an undercoat layer is formed as an intermediate layer provided between the base sheet and the porous layer. In such a heat-sensitive transfer image-receiving sheet, when the base sheet is resin-coated paper, there is a problem that interlayer adhesion between the base sheet and the porous layer via the undercoat layer is not sufficient. The problem is that after the undercoat layer, porous layer and receptor layer are applied simultaneously, the undercoat layer dries as the undercoat layer dries. It is thought that. The problem of interlayer adhesion between the base material sheet and the heat insulating layer is important because there is a possibility that cracks may occur on the surface of the receiving layer when the degree of slippage of the undercoat layer increases.

  In particular, when the coating solution for forming the undercoat layer, the porous layer, and the receiving layer is an aqueous coating solution containing water as a solvent, the above-described problem of interlayer adhesion tends to increase.

  This problem is improved by including hollow particles in the undercoat layer. The reason for this is considered to be that the hollow particles exhibit a function of relieving residual stress due to membrane slippage.

  However, when hollow particles are added to such an extent that the undercoat layer can be sufficiently removed, the surface unevenness of the resin-coated paper that forms the base sheet easily spreads to the surface state of the thermal transfer image-receiving sheet, and the thermal transfer image-receiving sheet. There is a risk that the surface of the surface may be roughened.

JP 2008-238673 A

  In view of the above problems, the present invention uses a resin-coated paper with surface irregularities as a base sheet, and has a structure in which an intermediate layer, a porous layer, and a receiving layer are laminated in this order on the base sheet. For the sheet, it suppresses the occurrence of roughness of the thermal transfer image-receiving sheet due to the surface unevenness of the resin-coated paper, ensures strong interlayer adhesion between the base material sheet and the porous layer via the intermediate layer, and cracks on the receiving layer surface It is an object of the present invention to provide a thermal transfer image-receiving sheet that suppresses the possibility of occurrence and a method for producing the same.

The present invention is (1) a thermal transfer image-receiving sheet in which an intermediate layer, a porous layer, and a receiving layer are formed in this order on a base sheet, the base sheet is made of resin-coated paper, and the intermediate layer is a base layer A first layer that contacts the material sheet and a second layer that contacts the porous layer and is formed between the first layer and the porous layer;
The intermediate layer contains a binder in the first layer and the second layer, and the first layer contains hollow particles formed in a hollow, and the second layer is formed in a hollow. Contain no hollow particles ,
A thermal transfer image receiving sheet, wherein the binder contained in the first layer and the second layer is made of gelatin or contains gelatin ;
(2) The first layer of the intermediate layer is hollow so that (the amount of hollow particles (parts by weight)) / (the amount of binders (parts by weight)) satisfies the range of 10/90 to 50/50. The thermal transfer image-receiving sheet according to (1), which contains particles;
(3) The thermal transfer image receiving sheet according to (1) or (2), wherein the intermediate layer contains a methyl methacrylate-butadiene copolymer in the first layer and the second layer,
(4) The first layer with an average particle diameter of a resin is 0.4Myuemu～1.5Myuemu, average hollow rate is contains hollow particles with 20% to 80%, from the (1) (3 ) The thermal transfer image-receiving sheet according to any one of
(5) On the base sheet, an intermediate layer composed of a first layer contacting the base sheet and a second layer formed on the first layer, a porous layer, and a receiving layer are formed in this order. A method for producing a thermal transfer image-receiving sheet, comprising:
A simultaneous multi-layer coating process in which a coating liquid for forming an intermediate layer, a porous layer, and a receiving layer is simultaneously multi-layer coated on a substrate sheet surface made of resin-coated paper to form a multi-layer coating film; And a step of drying after the coating film is cooled and gelled,
In the simultaneous multi-layer coating process, as the coating liquid for the intermediate layer, the porous layer, and the receiving layer, an aqueous coating liquid is used.
The coating liquid for forming the first layer and the second layer constituting the intermediate layer contains methyl methacrylate-butadiene copolymer and gelatin, and
The coating liquid for forming the first layer includes hollow particles made of a resin and formed hollow,
The coating liquid for forming the second layer does not contain hollow particles made of resin and formed hollow, and a method for producing a thermal transfer image-receiving sheet,
(6) The simultaneous multilayer coating step is summarized by the method for producing a thermal transfer image receiving sheet according to (5) , which is performed by a slide coating method.

  According to the present invention, the thermal transfer image-receiving sheet using a resin-coated paper as a base sheet suppresses the occurrence of roughness of the thermal-transfer image-receiving sheet due to the surface unevenness of the resin-coated paper, and a strong interlayer between the resin-coated paper and the porous layer It becomes possible to obtain a thermal transfer image receiving sheet that secures adhesiveness and suppresses the possibility of cracking on the receiving layer surface.

  By the way, the thermal transfer image-receiving sheet of the present invention is formed in a multilayer by providing layers such as an intermediate layer, a porous layer, and a receiving layer. ) Can be produced more efficiently if it is provided with a construction to which a production method can be applied. In this production method, a plurality of types of coating liquids constituting each layer to be formed on the base sheet surface are stacked one above the other and applied by a slide coat method or a curtain coat method to produce each layer. Is.

  In addition, when obtaining a thermal transfer image receiving sheet by the simultaneous multilayer coating method, a gelling agent is usually contained in each layer. In this regard, according to the present invention, when the binder constituting the intermediate layer contains a gelling agent, the intermediate layer, the porous layer, and the receiving layer can be formed by the simultaneous multilayer coating method. It is possible to effectively manufacture the sheet.

It is a cross-sectional schematic diagram which shows one of the Examples of the thermal transfer image receiving sheet of this invention. It is a cross-sectional schematic diagram which shows one of the other Examples in the thermal transfer image receiving sheet of this invention.

<Configuration of thermal transfer image receiving sheet 1>
As shown in FIG. 1, the present invention is a thermal transfer image receiving sheet 1 in which at least an intermediate layer 5, a porous layer 4, and a receiving layer 3 are laminated on a base sheet 2 in this order.

(Base material sheet 2)
The base sheet 2 is resin-coated paper. Specifically, the resin-coated paper is formed by using a paper such as glassine paper, condenser paper, paraffin paper or the like as a mount, and covering the surface of the mount with a resin such as polyethylene terephthalate, polyethylene, or polypropylene. Resin coated paper is manufactured by pasting a resin film on the backing sheet. In addition, after the resin is melted, the molten resin is coated on the backing surface to coat the backing surface with resin. What is manufactured by doing is also included.

  The thickness of the base sheet 2 can be appropriately changed according to the strength and heat resistance required for the thermal transfer image-receiving sheet 1 and the material of the material employed as the base sheet 2. The thickness of 2 is preferably in the range of 50 μm to 1000 μm, and more preferably in the range of 100 μm to 300 μm.

(Receptive layer 3)
The receiving layer 3 receives the sublimation dye transferred from the thermal transfer sheet at the time of image formation by thermal transfer, and holds the received sublimation dye in the receiving layer 3 so that an image is formed on the surface of the receiving layer 3. It is a layer for forming and maintaining the image.

  Therefore, the receiving layer 3 is formed of a resin material that can receive a sublimable dye (that is, has a dyeing property). Specifically, examples of the resin material for forming the receiving layer 3 include polyolefin resins such as polyethylene and polypropylene, polyvinyl chloride, vinyl chloride / vinyl acetate copolymers, halogenated polymers such as polyvinylidene chloride, and polyacetic acid. Vinyl polymers such as vinyl and polyacrylates, polyester resins such as polyethylene terephthalate and polybutylene terephthalate, polystyrene resins, polyamide resins, copolymers of olefins such as ethylene and propylene, and other vinyl monomers, ionomers , Cellulose resins such as cellulose diacetate, polycarbonate and the like, and vinyl resins and polyester resins are particularly preferable.

  The thickness of the receiving layer 3 may be appropriately selected as necessary, but the thickness is generally 1 to 50 μm, preferably within the range of 1 μm to 10 μm, and preferably within the range of 2 μm to 10 μm. It is more preferable that

  For the purpose of improving the whiteness of the receiving layer 3, additives such as kaolin clay, calcium carbonate and fine powder silica, additives such as white pigments and fluorescent brightening agents are added to the receiving layer 3 as appropriate. May be.

  The receiving layer 3 may contain a release agent as an additive in order to prevent thermal fusion between the thermal transfer sheet and the thermal transfer image receiving sheet 1 during image formation. Examples of the mold release agent include silicone oil, phosphate ester-based surfactant, and fluorine-based surfactant. Silicone oil is desirable. As the silicone oil, modified silicone oils such as epoxy modification, alkyl modification, amino modification, carboxyl modification, alcohol modification, fluorine modification, polyether modification, alkyl / aralkyl / polyether modification, and epoxy / polyether modification are desirable. . At this time, one type or two or more types of release agents may be used for the receiving layer 3. This release agent is used by being added to a resin composition such as a coating liquid containing a resin material for forming a receiving layer that is prepared when the receiving layer 3 is formed. The amount is preferably 0.5 to 30 parts by weight with respect to 100 parts by weight of the resin material forming the layer 3. By adding the release agent in this amount range, it is possible to obtain an effect of suppressing the possibility that the thermal transfer sheet is fused to the receiving layer 3 of the thermal transfer image receiving sheet 1 during the thermal transfer. It is possible to efficiently obtain the effect of reducing the risk of a decrease in sensitivity associated with the difficulty in separating the heat transfer image-receiving sheet 1 and the thermal transfer image-receiving sheet 1.

(Porous layer 4)
The porous layer 4 is a layer formed between the intermediate layer 5 and the receiving layer 3. Furthermore, the porous layer 4 is a layer containing hollow particles. Further, the porous layer 4 transfers heat applied to the receiving layer 3 from a heating medium such as a thermal head to the intermediate layer 5 and the base sheet 2 when an image is formed using the thermal transfer image receiving sheet 1. This is a layer having a heat insulating property to prevent the heat of the receiving layer 3 from being lost (heat diffusion) by heating.

(1) Hollow particles The hollow particles of the porous layer 4 have a function of imparting heat insulation to the porous layer 4. The hollow particles of the porous layer 4 are not particularly limited as long as desired heat insulating properties can be imparted to the porous layer 4. Therefore, the hollow particles may be expanded particles or non-expanded particles. The expanded particles may be independent expanded particles or continuous expanded particles. Furthermore, the hollow particles of the porous layer 4 may be organic hollow particles composed of resin or the like, or inorganic hollow particles composed of glass or the like. The hollow particles may be cross-linked hollow particles.

  Examples of the resin constituting the hollow particles include styrene resins such as crosslinked styrene-acrylic resins, (meth) acrylic resins such as acrylonitrile-acrylic resins, phenolic resins, fluorine resins, polyamide resins, and polyimide resins. Examples thereof include resins, polycarbonate resins, and polyether resins.

  The average particle diameter of the hollow particles contained in the porous layer 4 is particularly limited as long as the desired heat insulation and cushioning properties can be imparted to the porous layer 4 according to the type of resin constituting the hollow particles. Usually, it is preferably within a range of 0.1 μm to 15 μm, particularly preferably within a range of 0.1 μm to 10 μm. 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 the smooth porous layer 4.

  In the present specification, the “average particle diameter” is obtained as follows. A water dispersion is prepared by dispersing hollow particles in water, and the water dispersion of the hollow particles is dried to form a dry body, and then dried with a transmission electron microscope (manufactured by Hitachi High-Technologies Corporation). The particles (100 particles) forming the hollow particles in the body were observed, the diameter (outer diameter) on the outer surface side of each particle was measured, and these values were averaged to obtain the average particle diameter.

  Although it will not specifically limit as solid content concentration of the hollow particle contained in the porous layer 4 if the porous layer 4 which has desired heat insulation and cushioning properties can be obtained, for example, 30 mass%-90 mass %, Preferably in the range of 50% by mass to 80% by mass. This is because if the content is too small, the voids in the porous layer 4 are reduced, and sufficient heat insulating properties and cushioning properties may not be obtained. If the content is too large, the adhesiveness is inferior.

(2) Other compound Although the porous layer 4 contains a hollow particle at least, it may contain arbitrary other compounds as needed. Examples of such other compounds include a binder for forming a porous layer, a surfactant such as a nonionic silicone, a curing agent such as an isocyanate compound, a wetting agent, and a dispersing agent.

  As the porous layer forming binder, a water-based resin is usually used. Examples of such water-based resins include polyurethane resins such as acrylic urethane resins, polyester resins, gelatin, polyvinyl alcohol, polyethylene oxide, polyvinyl pyrrolidone, pullulan, carboxymethyl cellulose, hydroxyethyl cellulose, dextran, dextrin, and polyacrylic acid. And salts thereof, agar, κ-carrageenan, λ-carrageenan, ι-carrageenan, casein, xanthene gum, locust bean gum, alginic acid, gum arabic, and those described in JP-A-7-195826 and 7-9757. Homopolymerization of a real xylene oxide copolymer, water-soluble polyvinyl butyral, or a vinyl monomer having a carboxyl group or a sulfonic acid group described in JP-A-62-245260 And copolymers and the like. Moreover, you may use in combination of 2 or more types of the said resin.

(3) Porous layer 4
The porous layer 4 prevents heat applied from the thermal head to the receiving layer 3 from being transferred to the base sheet 2 or the like when an image is formed using the thermal transfer image receiving sheet 1. It has heat insulation. The degree of heat insulation of the porous layer 4 can be appropriately adjusted according to the use of the thermal transfer image receiving sheet 1 or the like. For example, the degree of heat insulation of the porous layer 4 can be specifically adjusted to an arbitrary range by changing the thickness of the porous layer 4.

The degree of heat insulation of the porous layer 4 can also be controlled by the porosity of the porous layer 4. In this regard, the porosity of the porous layer 4 is preferably in the range of 15% to 80%.
In addition, the porosity of the porous layer 4 refers to a value represented by (average hollow ratio of hollow particles of the porous layer 4) × (content ratio of hollow particles in the porous layer 4).

  In the present specification, the “average hollow ratio” is obtained as follows. A water dispersion is prepared by dispersing hollow particles in water, and the water dispersion of the hollow particles is dried to form a dry body, and then dried with a transmission electron microscope (manufactured by Hitachi High-Technologies Corporation). Particles (100 particles) forming hollow particles in the body were observed, and the diameter (inner diameter) on the inner surface side of each particle was measured, and these values were averaged to obtain the average particle inner diameter. Then, while determining the volume of the hollow part from the average particle inner diameter, the value was divided by the apparent volume of the particle from the average particle diameter and multiplied by 100 to calculate the average hollow ratio.

  The porous layer 4 has cushioning properties by including hollow particles. Here, the degree of cushioning property of the porous layer 4 can be appropriately adjusted according to the application of the thermal transfer image-receiving sheet 1 or the like. The degree of cushioning property of the porous layer 4 can also be adjusted to an arbitrary range by changing the thickness of the porous layer 4, for example.

The thickness of the porous layer 4 is not particularly limited as long as the heat insulating property, cushioning property and the like can be adjusted to a desired level, but it is preferably within a range of 10 μm to 100 μm, and 10 μm to 50 μm. It is more preferable to be within the range. The density of the porous layer 4, for example in the range of ^{0.1g / cm 3 ~0.8g / cm 3} , in a range of inter alia 0.2g ^/ cm ³ ~0.7g ^/ cm 3 preferable.

  The porous layer 4 may have a configuration composed of a single layer, or may have a configuration in which a plurality of layers are stacked. Here, the porous layer 4 having a configuration in which a plurality of layers are stacked may have a configuration in which layers of the same composition are stacked, or a configuration in which layers of different compositions are stacked. You may have. The porous layer 4 preferably has a configuration in which two layers having different compositions are laminated. By setting it as such a structure, the more functional porous layer 4 can be obtained.

  When the porous layer 4 has a two-layer structure, examples of the configuration of the porous layer 4 include the porous layer A containing the hollow particles a from the base sheet 2 side, and the average hollowness than the hollow particles a. The structure formed by laminating | stacking the porous layer B containing the small hollow particle b of this can be mentioned. When the porous layer 4 has such a configuration, the thermal transfer image-receiving sheet 1 provided with the porous layer 4 can prevent density unevenness and white spots in highlight portions during printing.

  The porous layer 4 may contain a cooling gelling agent as shown below. When the thermal transfer image-receiving sheet 1 is prepared by the simultaneous multilayer coating method, the porous layer 4 can be easily formed by the simultaneous multilayer coating method if the porous layer 4 includes a cooling gelling agent. it can.

(4) Cooling gelling agent The cooling gelling agent has a property of gelling when cooled, and “thermal transfer by simultaneously forming a plurality of layers on the substrate sheet 2 (simultaneous multilayer coating). The method is not particularly limited as long as “the method for producing image-receiving sheet 1” (simultaneous multilayer coating method) can be carried out. The cooling gelling agent preferably has a viscosity at 15 ° C. in a state dissolved in water of 3 times or more, particularly 5 times or more, more preferably 10 times or more of the viscosity at 80 ° C.

  Examples of the cooling gelling agent include gelatin, polyvinyl alcohol, agar, κ-carrageenan, λ-carrageenan, ι-carrageenan, pectin and the like.

  Gelatin is composed of peptide chains obtained by denaturing collagen having a triple helix structure as described above, and partially recovers the triple helix structure by cooling and recovers the recovered triple triplex structure. By forming a three-dimensional network starting from the helix structure, it exhibits cooling gelation characteristics.

  κ-carrageenan, λ-carrageenan and ι-carrageenan are natural polymer compounds mainly composed of galactose and 3,6-anhydrogalactose having a molecular weight of about 100,000 to 500,000 extracted from red algae seaweed. These are characterized by having a half-ester type sulfate group in the molecule, and usually exhibit cooling gelation properties when a thickener such as locust bean gum or a metal salt compound is used in combination.

  Pectin is a natural polysaccharide that constitutes the cell wall of plants, and exhibits cooling gelation characteristics when used in combination with an ionic compound.

  As the cooling gelling agent, only one type may be used, or two or more types of cooling gelling agents may be used.

  In the porous layer 4, the ratio between the hollow particles and the cooling gelling agent is not particularly limited as long as the porous layer 4 having a desired heat insulating property can be formed. The cooling gelling agent is preferably within a range of 10 to 50, in particular within a range of 10 to 40, more preferably within a range of 10 to 40, based on the solid content 100 in the porous layer 4. It is preferable to be within the range of 40. When the content ratio of the hollow particles and the cooling gelling agent is determined so that the cooling gelling agent is within this range, the porous layer 4 having further excellent heat insulating properties can be formed.

(Middle layer 5)
The intermediate layer 5 is a layer that is laminated at a position closer to the base material sheet 2 than the porous layer 4 when the thermal transfer image receiving sheet 1 is manufactured, and is located between the porous layer 4 and the base material sheet 2. This is a layer having a function of improving the adhesion between the porous layer 4 and the base sheet 2 and a function enabling high-speed coating when simultaneous multilayer coating is performed. Therefore, the material for forming the intermediate layer 5 is not particularly limited as long as both the porous layer 4 and the base sheet 2 have adhesion or high-speed coating suitability.

  The intermediate layer 5 has a two-layer structure formed by directly laminating the first layer 5a and the second layer 5b. The first layer 5 a is in contact with the base material sheet 2, and the second layer 5 b is in contact with the porous layer 4.

  The intermediate layer 5 contains a binder in both the first layer 5a and the second layer 5b, and the binder contains a resin material having a glass transition temperature (Tg) of 20 ° C. or less. Yes. At this time, the intermediate layer 5 includes a resin material having a glass transition temperature (Tg) of 20 ° C. or less. This causes roughness of the thermal transfer image-receiving sheet 1 due to the unevenness of the base sheet 2. The risk of being lost is suppressed.

  As the binder constituting the intermediate layer 5, a water-based resin is usually used. Specifically, examples of the water-based resin include polyurethane resins such as acrylic urethane resins, polyester resins, gelatin, polyvinyl alcohol, polyethylene oxide, polyvinyl pyrrolidone, pullulan, carboxymethyl cellulose, hydroxyethyl cellulose, dextran, dextrin, and polyacrylic acid. And salts thereof, agar, κ-carrageenan, λ-carrageenan, ι-carrageenan, casein, xanthene gum, locust bean gum, alginic acid, gum arabic, and those described in JP-A-7-195826 and 7-9757. Real weight of a vinyl monomer having a carboxyl group or a sulfonic acid group described in JP-A-62-245260, or a real xylene oxide copolymer, water-soluble polyvinyl butyral It can be mentioned body or copolymer of resin. Further, two or more kinds of resins as listed here may be combined and used as a binder. And it is preferable that resin which has adhesiveness with respect to the base material sheet 2 and the porous layer 4 is suitably selected from such resin, and used as a binder.

  In addition, as a binder, when the sublimation dye is thermally transferred to the thermal transfer image receiving sheet 1, there is an effect that moisture of the sublimation dye may be transferred to the base sheet 2 through the receiving layer 3 and the porous layer 4. From the standpoint of prevention, water-soluble resins such as polyvinyl alcohol, carboxymethyl cellulose, and sodium polyacrylate are preferably used. Since these water-soluble resins have higher viscosity and better water retention than other resins that are not water-soluble resins, it is possible to effectively prevent moisture from penetrating into the base sheet 2.

  Examples of the resin material having a glass transition temperature (Tg) of 20 ° C. or less included in the first layer 5a and the second layer 5b constituting the intermediate layer 5 include latex, for example, methyl methacrylate-butadiene. Examples thereof include a copolymer (MBR), a butadiene-styrene copolymer (SBR), and a nitrile butadiene rubber (NBR). Thus, as a resin material having a glass transition temperature (Tg) of 20 ° C. or less, methyl methacrylate-butadiene copolymer is preferably used in terms of heat resistance and weather resistance better than SBR and NBR.

  In addition, the glass transition temperature (Tg) here is calculated | required based on the measurement of the calorie | heat amount change by DSC (differential scanning calorimetry) (DSC method).

  The methyl methacrylate-butadiene copolymer is formed by emulsion polymerization of methacrylate and butadiene, and usually forms crosslinked fine particles having a crosslinked structure by a crosslinking reaction with butadiene.

  The first layer 5a of the intermediate layer 5 includes hollow particles. The hollow particles can be appropriately selected from “selectable as hollow particles contained in the porous layer 4”.

  In the 1st layer 5a, the mixture ratio (PV ratio) of a hollow particle and a binder is a ratio which can obtain the layer structure which has heat insulation and cushioning properties.

  In the first layer 5a, the PV ratio is in the range of 10/90 to 50/50, and more preferably 20/80 to 40/60. If the PV ratio is too low, the amount of the hollow particles will be too small, and the first layer 5a may not be able to fully exhibit the membrane slip prevention effect. If the PV ratio is too high, the amount of the hollow particles will be too high. There is a possibility that the adhesion between the first layer 5a and the base sheet 2 is lowered.

  The PV ratio is a value determined by (the amount of hollow particles (the amount of solid content of the hollow particles) (parts by weight)) / (the amount of binder (the amount of solids of the binder) (parts by weight)). It is. The blending amount of the binder is the sum of the solid contents of each resin when there are a plurality of resins constituting the binder. For example, when the binder is only gelatin, it is the solid content of gelatin. When the binder is made of gelatin and a methyl methacrylate-butadiene copolymer, it is the sum of the solid content of gelatin and the solid content of methyl methacrylate-butadiene copolymer.

  Regarding the thickness of the intermediate layer 5, the total thickness of the intermediate layer 5 is in the range of 1 μm to 20 μm from the viewpoint of ensuring the heat insulation and cushioning properties of the thermal transfer image-receiving sheet 1 and suppressing the possibility of high manufacturing costs. Preferably there is. Regarding the thickness of the intermediate layer 5, the ratio of the thickness of the first layer 5a and the thickness of the second layer 5b is (thickness of the first layer 5a (μm)) and (thickness of the second layer 5b ( It is preferred that the ratio be such that either one of μm)) does not become extremely large. This is to achieve both the film slip suppression effect of the first layer 5a of the intermediate layer 5 and the adverse effect (roughness) suppression effect of the unevenness of the base sheet 2 by the second layer 5b.

  The hollow particles are resin-made hollow particles formed by forming a hollow portion inside an outer shell made of a thermoplastic resin. The hollow particles contain air or other gas in the hollow portion when the first layer 5a is in a dry state, and in the hollow portion when the first layer 5a is wet with a liquid such as water, Contains water and other liquids.

  The average particle diameter of the hollow particles is preferably 0.4 μm to 10 μm, more preferably 0.4 μm to 4 μm, and still more preferably 0.4 μm to 1.5 μm. The average hollowness of the hollow particles is preferably in the range of 20% to 80%, more preferably 30% to 80%, and further preferably 40% to 60%. If the average hollowness of the hollow particles is too low, there is a possibility that sufficient space can be secured in the first layer 5a, and sufficient heat insulation and cushioning properties may not be obtained. If the average hollowness is too high, the outer shell There is a possibility that the thickness of the film becomes thin and it may be crushed during coating or printing.

  The “average particle diameter” and “average hollow ratio” of the hollow particles contained in the first layer 5 a of the intermediate layer 5 are determined by the same method as the hollow particles of the porous layer 4.

  The material constituting the hollow particles contained in the first layer 5 a of the intermediate layer 5 may be appropriately selected from the same materials as the hollow particles contained in the porous layer 4. Therefore, the material constituting the hollow particles may be an organic resin material or an inorganic material. However, from the viewpoint of affinity with the binder, the hollow particles are preferably made of an organic resin material. Examples of organic resin materials include styrene resins such as crosslinked styrene-acrylic resins, acrylic resins such as acrylonitrile-acrylic resins or (meth) acrylic resins, phenolic resins, fluorine resins, polyamide resins, and polyimide resins. And polycarbonate resins and polyether resins.

  As the hollow particles, either foamed particles or non-foamed particles may be used. For example, organic foamed particles made of a foamed material such as a cross-linked styrene-acrylic resin, inorganic hollow glass bodies, and the like can be used as the hollow particles. When foamed particles are used as the hollow particles, the foamed state may be either closed foam or continuous foam.

  The intermediate layer 5 does not contain hollow particles formed in the second layer 5b. Therefore, the intermediate layer 5 is configured such that the first layer 5a in contact with the base sheet 1 contains hollow particles and the second layer 5b in contact with the porous layer 4 does not contain hollow particles. It becomes.

  In the present specification, the concept of the phrase “the intermediate layer 5 does not contain hollow particles formed hollow in the second layer 5b” is the concept that the first layer to the second layer in the painting process or the like. It is not a concept that excludes the presence of hollow particles mixed in, but is a level that does not harm the function of the second layer 5b (the function of imparting the effect of suppressing the adverse effect (roughness) caused by the unevenness of the base sheet 2). The concept includes a case where a small amount of hollow particles (less than the lower limit amount of the hollow particles contained in the first layer) is mixed in the second layer 5b. Therefore, “the intermediate layer 5 does not contain hollow particles formed hollow in the second layer” means that “the second layer is positively added with hollow particles like the first layer”. This corresponds to the case of “not the layered structure”.

  However, ideally, the intermediate layer 5 is preferably configured such that the second layer does not contain hollow particles formed in the hollow at all.

<Method for producing thermal transfer image-receiving sheet 1>
The thermal transfer image receiving sheet 1 of the present invention can be manufactured as follows.

“Coating fluid adjustment process”
(1) Coating liquid for forming the receiving layer As a resin material constituting the receiving layer 3, a resin material having dye-dyeing property with respect to a sublimation dye is selected, and the selected resin material is dispersed and dissolved in a solvent. Adjust the coating solution for forming the receiving layer. The solvent used when adjusting the coating liquid for forming the receiving layer is not particularly limited as long as the resin material can be dispersed or dissolved, and any of an oil-based solvent and an aqueous solvent can be employed.

  Here, the “oil-based solvent” indicates a solvent of an organic compound.

  The “aqueous solvent” refers to a solvent containing water as a main component, and the ratio of water in the aqueous solvent is usually 60% by weight or more, preferably 70% by weight or more, and more preferably 80%. % By weight or more. As the “solvent other than water” constituting the aqueous solvent, a solvent mixed with water can be appropriately selected. For example, alcohols such as methanol, ethanol, isopropanol and n-propanol; glycols such as ethylene glycol, diethylene glycol and glycerin Preferred examples include esters such as ethyl acetate and propyl acetate; ketones such as acetone and methyl ethyl ketone; amides such as N, N-dimethylformamide and the like.

(2) Coating liquid for forming porous layer A material for forming porous layer 4 is selected, and the selected material is dissolved and dispersed in a solvent to prepare a coating liquid for forming the porous layer. As the solvent used when adjusting the coating liquid for forming the porous layer, an aqueous solvent is employed as in the case of forming the receiving layer 3.

(3) Coating liquid for forming the intermediate layer As a coating liquid for forming the intermediate layer for forming the intermediate layer 5, a coating liquid for forming the first layer for forming the first layer 5a is used. And a coating liquid for forming a second layer for forming the second layer 5b.

  For the first layer forming coating solution and the second layer forming coating solution, the material for forming each layer 5a, 5b is selected, and the selected material is dissolved and dispersed in the solvent. Adjusted. The coating liquid for forming the first layer and the coating liquid for forming the second layer are different in that the hollow particles are added only to the coating liquid for forming the first layer.

  As the solvent used for adjusting the coating liquid for forming the first layer and the coating liquid for forming the second layer, the same solvent is used, and when the coating liquid for forming the receiving layer is adjusted, The “aqueous solvent” used is used.

“Production and drying process of coating film”
A base sheet 2 is prepared, and the first layer forming coating solution prepared in (3) above is applied onto the base sheet surface 2 to form a coating film (first layer forming coating). Film) is produced. As a method for producing the coating film, a general coating method such as a gravure coating method, a gravure reverse coating method, a comma coating method, a die coating method, a lip coating method, a slide coating method, or a curtain coating method may be appropriately employed. it can.

  And after preparation of a coating film, the coating film is dried. By this drying, the first layer-forming coating film forms the first layer 5a. Although the drying temperature at the time of this drying is suitably set according to the composition of the coating liquid, it is usually preferably in the range of 30 ° C to 120 ° C.

  On the exposed surface of the first layer 5a produced on the surface of the base sheet 2, the coating liquid for forming the second layer is used for the base sheet 2 to form a coating film and to dry it. The first layer 5a is further laminated. Thereby, the intermediate layer 5 is laminated.

  Next, on the exposed surface of the intermediate layer 5 produced on the surface of the base material sheet 2, the porous layer 4 and the above (1) are sequentially applied by the coating liquid for forming the porous layer shown in the above (3). The receiving layer 3 is formed from the coating liquid for forming the receiving layer shown. At this time, as a coating method and a drying method of these coating liquids, the coating method and the drying method used for the production of the first layer-forming coating film can be appropriately employed.

  Thus, the thermal transfer image receiving sheet 1 of the present invention is specifically produced.

  In the description of the manufacturing method of the thermal transfer image-receiving sheet 1 of the present invention, the manufacturing method is described as an example in which the intermediate layer 5, the porous layer 4, and the receiving layer 3 are individually formed. It is not limited to this. The manufacturing method of the thermal transfer image-receiving sheet 1 is more preferably a method in which a plurality of layers such as the intermediate layer 5, the porous layer 4, and the receiving layer 3 are simultaneously formed.

  In the production of the thermal transfer image receiving sheet 1, as a method of simultaneously forming a plurality of layers (intermediate layer 5, porous layer 4 and receiving layer 3) constituting the thermal transfer image receiving sheet 1, the intermediate layer 5 constituting the thermal transfer image receiving sheet 1 is used. The coating liquid for forming the porous layer 4 and the receiving layer 3 is formed by stacking coating films having a uniform thickness on top and bottom without being mixed with each other (simultaneous multilayer coating method (or simultaneous multilayer coating method). In particular, the coating liquid for forming a coating film for forming each layer (intermediate layer 5, porous layer 4, and receiving layer 3) is moved up and down. A slide coat method and a curtain coat method are preferably used in which a coating film is produced by discharging the material onto the surface of the base material sheet in the overlapped state and performing slide coating.

  In the production of the thermal transfer image receiving sheet 1, when the slide coating method is used as the simultaneous multilayer coating method as described above, the thermal transfer image receiving sheet 1 is obtained in the simultaneous multilayer coating step as follows.

  First, on the surface of the base sheet 2, the first layer forming coating liquid, the second layer forming coating liquid, and the porous layer forming coating are arranged in order from the side closer to the base sheet 2 surface. The coating liquid for forming the liquid and the receiving layer is applied while being overlapped without crossing up and down to form the first layer-forming coating film, the second layer-forming coating film, and the porous layer formation. The coating film for forming the coating film and the coating film for forming the receiving layer are formed in separate layers one above the other at a time, and four coating films are formed on the surface of the substrate sheet 2.

  Next, the four-layer coating film is cooled (cooling step). At this time, the cooling temperature is not particularly limited as long as the viscosity of the four-layer coating films can be improved to such an extent that these coating films do not mix with each other. . Specifically, the cooling temperature in the cooling step is preferably in the range of −10 ° C. to 30 ° C., particularly preferably in the range of −10 ° C. to 25 ° C., and further in the range of −5 ° C. to 20 ° C. It is preferable that In order to enable the cooling process to be carried out smoothly, it is preferable that a cooling gelling agent is contained in the binder of each coating film. Therefore, it is preferable that each coating liquid for forming each coating film contains a cooling gelling agent (cooling gelling agent).

  Then, after the cooling step, the four coating films are dried. At this time, the drying is performed by applying heat to the base sheet 2 on which the four-layer coating film is formed. In addition, when the gelling agent is contained in the four-layer coating film, and the binder contained in the four-layer coating film includes the gelling agent for cooling, it is applied at the time of drying. The possibility of mutual mixing during wind and transport is suppressed.

  In addition, when the gelling agent is contained in the four-layer coating film, the coating liquid for forming each coating film contains a cooling gelling agent. A compound capable of gelling the solvent can be used as appropriate, and examples thereof include resin materials that can function as a gelling agent such as gelatin, carrageenan, and agar. Gelatin is preferable because it can be dissolved at a low temperature and can be dissolved at a high concentration.

  In forming each layer (intermediate layer 5, porous layer 4, and receiving layer 3) constituting the thermal transfer image-receiving sheet 1 of the present invention, a coating solution that is adjusted when forming each layer, if necessary. In addition, additives such as an aqueous film auxiliary, leveling agent, antifoaming agent, and dispersing agent may be further added.

<Other forms of thermal transfer image-receiving sheet 1>
In the above description, the thermal transfer image-receiving sheet 1 of the present invention has been described in detail as an example in which the base layer 2 is formed with the intermediate layer 5, the porous layer 4, and the receiving layer 3. However, the present invention is not limited thereto. Alternatively, the thermal transfer image receiving sheet 1 may be further formed with the following layers.

  That is, the thermal transfer image receiving sheet 1 of the present invention may be one in which a primer layer 6 is provided between the porous layer 4 and the receiving layer 3 as shown in FIG.

<Regarding the primer layer 6>
In the thermal transfer image receiving sheet 1, the primer layer 6 is a layer having a function of improving the adhesion between the porous layer 4 and the receiving layer 3. Therefore, the material for forming the primer layer 6 is not particularly limited as long as it has adhesion to both the porous layer 4 and the receiving layer 3. Specifically, the material forming the primer layer 6 is preferably appropriately selected from resin materials that can be dispersed and dissolved in an aqueous resin that can be selected as the thermoplastic resin constituting the porous layer 4.

  The primer layer 6 can be formed as follows.

"Adjustment of coating solution"
A material for forming the primer layer 6 is selected, and the selected material is dissolved and dispersed in a solvent to prepare a primer layer forming coating solution. As the solvent used when adjusting the coating liquid for forming the primer layer, any of an oil-based solvent and an aqueous solvent can be employed as in the case of forming the receiving layer.

"Preparation and drying of coating film"
On the substrate sheet 2 on which the intermediate layer 5 and the porous layer 4 are laminated, a primer layer forming coating solution is applied onto the exposed surface of the porous layer 4 to form a coating film (primer layer formation). The primer layer forming coating film forms the primer layer 6 by drying the primer layer forming coating film. And the receiving layer 3 is formed on the primer layer 6, and the thermal transfer image receiving sheet 1 is obtained.

  In manufacturing the thermal transfer image receiving sheet 1 having the primer layer 6 as described above, each layer (intermediate layer 5, porous layer 4, primer layer 6, and receiving layer 3) constituting the thermal transfer image receiving sheet 1 is individually provided. A sequential forming method may be used, and a simultaneous multilayer coating method (simultaneous multilayer coating method) by a slide coating method may be used. From the viewpoint of efficiently producing the thermal transfer image-receiving sheet 1, a simultaneous multilayer coating method by a slide coating method is preferable.

  When the thermal transfer image-receiving sheet 1 provided with the primer layer 6 is produced by the simultaneous multilayer coating method, the intermediate layer 5, the porous layer 4, the primer layer 6 and the receiving layer 3 are arranged in this order by the simultaneous multilayer coating process. It can be formed on two surfaces at once. When the thermal transfer image-receiving sheet 1 is manufactured by the simultaneous multi-layer forming method by the slide coating method, adjustment is made when forming each layer (intermediate layer 5, porous layer 4, receiving layer 3, primer layer 6). The coating liquid contains a gelatinizer for cooling such as gelatin, or a gelling agent for cooling is selected as the resin composition corresponding to the material constituting each layer. Thus, when each coating liquid for constituting each layer includes a cooling gelling agent, the cooling step in the step of producing the thermal transfer image-receiving sheet 1 of the present invention by the simultaneous multilayer coating method. The thermal transfer image receiving sheet 1 can be obtained effectively.

  The present invention will now be illustrated in more detail using examples.

"Adjustment of coating solution"
(1) Receiving layer forming coating solution The composition shown in the following Table 1 was mixed to prepare a receiving layer forming coating solution (referred to as liquid A). The compounding amounts for each composition component are as shown in Table 1.

(2) Porous layer forming coating solution The composition shown in the following Table 2 to Table 4 was mixed, and the porous layer forming coating solution (Liquid B-1) shown in each of Tables 2 to 4 was mixed. To liquid B-3). The compounding amounts for each composition component are as shown in Tables 2 to 4.

(3) Coating liquid for forming an intermediate layer Regarding the coating liquid for forming an intermediate layer, the coating liquid (forms the first layer) for each of the first layer and the second layer that can constitute the intermediate layer. Coating liquid (first layer forming coating liquid) and coating liquid for forming the second layer (second layer forming coating liquid)) were prepared.

(4) First layer-forming coating solution The first layer-forming coating solution shown in each of Tables 5 to 12 by mixing the components shown in Tables 5 to 12 below. (Liquid C-1-A to Liquid C-1-C, Liquid C-2 to Liquid C-6) were prepared. The compounding amounts of the respective composition components are as shown in Tables 5 to 12.

  Glass transition of latex component (MBR or SBR) in the binder for each of liquid C-1-A, liquid C-1-B, liquid C-1-C, and liquid C-2 to liquid C-6 Temperature (Tg), hollow particle blending ratio (hollow particle blending amount (parts by weight) / (binder blending amount (parts by weight)), hollow particle mean particle diameter (μm), hollow particle mean hollowness (% ) Is shown in the following Table 13. The binder content corresponds to the sum of the latex content and the gelatin content.

(5) Second layer forming coating solution Second layer forming coating solution shown in Tables 14 to 17 by mixing the components shown in Tables 14 to 17 below. (Liquid D-1 to Liquid D-4) were adjusted. The compounding amounts for each composition component are as shown in Tables 14 to 17. In Tables 14 to 17, Tg represents a glass transition temperature.

"Production of thermal transfer image-receiving sheet"
Using the above coating solution, a thermal transfer image receiving sheet was prepared as follows.

Example 1.
Resin coated paper (RC paper (STF-150, manufactured by Mitsubishi Paper Industries)) was prepared as a base sheet. Next, as shown in Tables 18 and 19, as the coating liquid for forming the first layer and the second layer constituting the intermediate layer, the first layer-forming coating liquid and the second layer formation Two types of coating liquids were selected, and further, a coating liquid for forming a porous layer and a coating liquid for forming a receiving layer for forming each of the porous layer and the receiving layer were selected.

  Using the first layer forming coating solution, the second layer forming coating solution, the porous layer forming coating solution, and the receiving layer forming coating solution shown in Tables 18 and 19, these four types of coating solutions were used. The coating liquid is heated to 50 ° C., and the coating liquid 1 and the second layer forming coating are sequentially applied from the side closer to the base sheet on the surface of the base sheet by the simultaneous multilayer coating method by the slide coating method. The coating solution, the porous layer forming coating solution, and the receiving layer forming coating solution are applied while being superposed in the vertical direction, and a four-layer coating film (first layer forming coating) is applied on the substrate sheet surface. Film, second layer forming coating film, porous layer forming coating film and receptor layer forming coating film). The coating amount of each coating solution is as shown in Tables 18 and 19.

  Next, the base material sheet on which the four-layer coating film was formed was cooled to 5 ° C., and the cooled state was maintained for 1 minute (cooling treatment). By this cooling treatment, each coating film is gelled. After the cooling treatment, the base material sheet on which the four-layer coating film was formed was heated to 50 ° C. and held in that state for 5 minutes to dry the four-layer coating film (drying processing). By this drying treatment, a laminated structure in which the intermediate layer composed of the first layer and the second layer, the porous layer, and the receiving layer were laminated in this order on the base sheet surface was formed, and a thermal transfer image receiving sheet was obtained. .

  Using the obtained thermal transfer image-receiving sheet, the following measurements were performed to evaluate the roughness and interlayer adhesion between the base sheet and the porous layer. The results are shown in Table 20.

"Roughness"
Roughness was measured by a printing test. The printing test was carried out by printing a predetermined image on the obtained thermal transfer image-receiving sheet by a sublimation thermal transfer method. At this time, a black image divided into 18 steps is used as the predetermined image to be printed. As a device for performing printing by the sublimation type thermal transfer method, a sublimation type thermal transfer printer (manufactured by ALTECH ADS; MEGAIXEL III) is used. As the thermal transfer sheet, a dedicated ink ribbon that can be used in a sublimation thermal transfer printer (manufactured by ALTECH ADS; MEGAPIXEL III) was used.

Then, after an image divided into 18 steps of black was formed on the thermal transfer image receiving sheet, the roughness of the transferred image was visually observed to make the following determination.
Good: No rough feeling is observed. Normal: At first glance, no rough feeling is observed, but when close to the transferred image, a slight rough feeling is recognized. Bad: At first glance, rough feeling is recognized.

"Interlayer adhesion"
Adhesive material (mending tape (manufactured by 3M; Scotch Brand; Scotch Brand) is applied to the region inside the side edge of the thermal transfer image-receiving sheet (dimension: length × width is 5 (cm) × 5 (cm)). Tape MP-12)) was pasted. After attaching the adhesive material to the thermal transfer image receiving sheet, the positional relationship between the surface of the thermal transfer image receiving sheet and the surface of the adhesive material is such that the surface of the adhesive material forms a 45-degree angle with respect to the surface of the thermal transfer image receiving sheet. Further, the adhesive was peeled from the thermal transfer image receiving sheet. At this time, the “interlayer adhesion” between the base material sheet and the porous layer indicates that the pressure-sensitive adhesive is peeled off at the contact interface between the pressure-sensitive adhesive and the thermal transfer image-receiving sheet, or the pressure-sensitive adhesive is part of the layer constituting the thermal transfer image-receiving sheet. It was evaluated as follows by observing whether peeling of the pressure-sensitive adhesive occurred while producing a portion following the above.
Good: No part of the layer constituting the thermal transfer image-receiving sheet follows the pressure-sensitive adhesive, and the peeling occurs cleanly at the interface between the pressure-sensitive adhesive and the thermal transfer image-receiving sheet. Normal: Configures the thermal transfer image-receiving sheet The area of the part of the porous layer that peeled off following the adhesive remained at 5% or less of the contact area between the adhesive and the thermal transfer image-receiving sheet before peeling the adhesive. And the area of the part which peeled off exceeded 5% of the contact area of the adhesive and thermal transfer image receiving sheet before adhesive removal.

Examples 2 to 10
As for Examples 2 to 10, as shown in the columns of Examples 2 to 10 in Tables 18 and 19, the first coating liquid for forming the first layer and the second layer constituting the intermediate layer is the first. Two types of coating liquid for layer formation and coating liquid for second layer formation are selected, and further, a coating liquid for forming a porous layer and a receiving layer formation for forming each of the porous layer and the receiving layer A thermal transfer image-receiving sheet was prepared using the same method as in Example 1 except that the coating liquid was selected. Using the thermal transfer image-receiving sheets obtained for Examples 2 to 10 respectively, the same method as in Example 1 was used to evaluate the roughness and interlayer adhesion between the base sheet and the porous layer. The results are shown in Table 20.

Comparative Example 1
As shown in the column of Comparative Example 1 in Tables 18 and 19, only the coating solution for forming the second layer is selected as the coating solution for forming the intermediate layer, and further, the porous layer and the receiving layer are selected. A thermal transfer image-receiving sheet was prepared using the same method as in Example 1 except that a porous layer-forming coating solution and a receiving layer-forming coating solution for forming each of the layers were selected. The thermal transfer image receiving sheet of Comparative Example 1 forms an intermediate layer with only the second layer. Using the thermal transfer image-receiving sheet obtained for Comparative Example 1, the same method as in Example 1 was used to evaluate the roughness and interlayer adhesion between the base sheet and the porous layer. The results are shown in Table 20.

DESCRIPTION OF SYMBOLS 1 Thermal transfer image receiving sheet 2 Base material sheet 3 Receiving layer 4 Porous layer 5 Intermediate | middle layer 5a 1st layer 5b 2nd layer 6 Primer layer

Claims (6)

A thermal transfer image receiving sheet in which an intermediate layer, a porous layer, and a receiving layer are formed in this order on a base sheet, wherein the base sheet is made of resin-coated paper, and the intermediate layer is in contact with the base sheet. And a second layer that is in contact with the porous layer and formed between the first layer and the porous layer,
The intermediate layer contains a binder in the first layer and the second layer, and the first layer contains hollow particles formed in a hollow, and the second layer is formed in a hollow. Contain no hollow particles ,
The thermal transfer image-receiving sheet , wherein the binder contained in the first layer and the second layer is made of gelatin or contains gelatin .   The first layer of the intermediate layer contains hollow particles so that (the amount of hollow particles (parts by weight)) / (the amount of binders (parts by weight)) satisfies the range of 10/90 to 50/50. The thermal transfer image receiving sheet according to claim 1.   The thermal transfer image receiving sheet according to claim 1 or 2, wherein the intermediate layer contains a methyl methacrylate-butadiene copolymer in the first layer and the second layer. 4. The first layer according to claim 1, wherein the first layer is made of a resin and contains hollow particles having an average particle diameter of 0.4 μm to 1.5 μm and an average hollowness of 20% to 80%. Thermal transfer image receiving sheet.   Thermal transfer in which an intermediate layer, a porous layer, and a receiving layer composed of a first layer in contact with the substrate sheet and a second layer formed on the first layer are formed in this order on the substrate sheet A method of manufacturing an image receiving sheet,
  A simultaneous multi-layer coating process in which a coating liquid for forming an intermediate layer, a porous layer, and a receiving layer is simultaneously multi-layer coated on a substrate sheet surface made of resin-coated paper to form a multi-layer coating film; And a step of drying after the coating film is cooled and gelled,
  In the simultaneous multi-layer coating process, as the coating liquid for the intermediate layer, the porous layer, and the receiving layer, an aqueous coating liquid is used.
  The coating liquid for forming the first layer and the second layer constituting the intermediate layer contains methyl methacrylate-butadiene copolymer and gelatin, and
  The coating liquid for forming the first layer includes hollow particles made of a resin and formed hollow,
  A method for producing a thermal transfer image receiving sheet, characterized in that the coating liquid for forming the second layer does not contain hollow particles made of resin and formed hollow. The method for producing a thermal transfer image receiving sheet according to claim 5 , wherein the simultaneous multilayer coating step is performed by a slide coating method.

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