Thermal transfer image receiving sheet, method for producing printed matter, and printed matter

Abstract

To provide a thermal transfer image receiving sheet having Japanese paper as a substrate, the thermal transfer image receiving sheet preventing fibers composing the Japanese paper from falling at an operation of a thermal transfer printer (when the sheet is conveyed) while maintaining an appearance and a touch feeling of the Japanese paper.SOLUTION: A thermal transfer image receiving sheet includes a back layer, a substrate and a reception layer in this order. The substrate includes a Japanese paper substrate. The back layer contains water-soluble polysaccharide. When the thermal transfer image receiving sheet and a black color reference plate with ISO visual density of 1.81 are overlapped, and the ISO visual density of the black color reference plate from a thermal transfer image receiving sheet side through the thermal transfer image receiving sheet is measured, the value is 0.20 to 0.70.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a thermal transfer image receiving sheet, a method for producing a printed matter, and a printed matter. [Background technology]

[0002] Various image forming methods are known in the art. Among them, the dye-sublimation thermal transfer method allows the density gradation to be freely adjusted, has excellent reproducibility of intermediate colors and gradations, and is capable of forming high-quality images comparable to silver halide photography.

[0003] In this sublimation thermal transfer method, a thermal transfer sheet having a sublimation transfer color material layer containing a sublimation dye is superimposed on a thermal transfer image receiving sheet having a receiving layer, and the thermal transfer sheet is then heated by a heating element such as a thermal head provided on the printer, thereby transferring the sublimation dye in the sublimation transfer color material layer to the receiving layer to form an image, thereby obtaining a printed matter.

[0004] 2. Description of the Related Art Conventionally, thermal transfer image-receiving sheets have been known that have the appearance and feel of Japanese paper (see, for example, Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 05-032077 [Patent Document 2] Japanese Patent Application Publication No. 06-262868 Summary of the Invention [Problem to be solved by the invention]

[0006] The present inventors have found that when a thermal transfer image-receiving sheet having Japanese paper as a substrate is used, the fibers constituting the Japanese paper fall off from the substrate and contaminate the grip rollers and the like provided in the thermal transfer printer.

[0007] The problem that the present disclosure aims to solve is to provide a thermal transfer image receiving sheet having Japanese paper as a base material, which maintains the appearance and feel of Japanese paper while suppressing the falling off of the fibers that make up the Japanese paper when the thermal transfer printer is operating (when the sheet is being transported), and to provide a method for producing a printed matter using the thermal transfer image receiving sheet, and a printed matter. [Means for solving the problem]

[0008] The thermal transfer image receiving sheet of the present disclosure comprises a back layer, a substrate, and a receiving layer in this order, the substrate comprises a Japanese paper substrate, and the back layer contains a water-soluble polysaccharide. Here, when the thermal transfer image receiving sheet and a black reference plate having an ISO visual density of 1.81 are superimposed and the ISO visual density of the black reference plate is measured from the thermal transfer image receiving sheet side through the thermal transfer image receiving sheet, the value is 0.20 or more and 0.70 or less.

[0009] The method for producing a print according to the present disclosure includes (1) a step of preparing the thermal transfer image receiving sheet, and (2) a step of forming an image on a receiving layer of the thermal transfer image receiving sheet.

[0010] The printed matter of the present disclosure comprises the thermal transfer image receiving sheet and an image formed on a receiving layer of the thermal transfer image receiving sheet. Effect of the Invention

[0011] According to the present disclosure, it is possible to provide a thermal transfer image receiving sheet having Japanese paper as a base material, which maintains the appearance and feel of Japanese paper while suppressing the shedding of the fibers that make up the Japanese paper when the thermal transfer printer is operating (when the sheet is being transported), and it is also possible to provide a method for producing a printed matter using the thermal transfer image receiving sheet, and a printed matter. [Brief description of the drawings]

[0012]

Figure 1

Figure 2

Figure 3

[0013] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings, etc. Note that the present disclosure can be embodied in many different forms, and should not be construed as being limited to the description of the embodiments exemplified below.

[0014] In order to clarify the explanation, the drawings may be schematic in terms of the width, thickness, angle, shape, etc. of each part compared to the actual form. However, the drawings are merely examples and do not limit the interpretation of the present disclosure. In this specification and each figure, elements similar to those described with respect to the previous figures may be given the same reference numerals, and detailed explanations may be omitted as appropriate. For convenience of explanation, the explanation will be made using the terms up and down, but the up-down direction may be reversed. The same applies to the left-right direction.

[0015] [Thermal transfer image receiving sheet] The thermal transfer image receiving sheet of the present disclosure includes a back layer, a substrate, and a receiving layer in this order in the thickness direction. In the present disclosure, the side of the substrate opposite to the receiving layer is also referred to as the "back side".

[0016] A thermal transfer image receiving sheet 10 of one embodiment shown in Fig. 1 comprises, in the thickness direction, a back layer 12, a base material 14 which is a Japanese paper base material 14-1, and a receiving layer 16. A thermal transfer image receiving sheet 10 of another embodiment shown in Fig. 2 comprises, in the thickness direction, a back layer 12, a base material 14, and a receiving layer 16, and the base material 14 comprises, in the thickness direction, a Japanese paper base material 14-1, an adhesive layer 14-2, and a transparent resin layer 14-3, in the thickness direction. The thermal transfer image receiving sheet 10 may comprise a primer layer (not shown) between the transparent resin layer 14-3 and the receiving layer 16.

[0017] The thermal transfer image receiving sheet of the present disclosure has a value of 0.20 to 0.70, preferably 0.25 to 0.65, more preferably 0.30 to 0.60, when the thermal transfer image receiving sheet and a black reference plate with an ISO visual density of 1.81 are superimposed and the ISO visual density of the black reference plate is measured from the thermal transfer image receiving sheet side through the thermal transfer image receiving sheet. In such a thermal transfer image receiving sheet, the Japanese paper substrate can be seen through from the receiving layer side. Therefore, the thermal transfer image receiving sheet of the present disclosure has the appearance of Japanese paper. In the above measurement, the black reference plate and the back side (specifically, the back layer) of the thermal transfer image receiving sheet are overlapped so that they are in contact with each other, and the ISO visual density of the black reference plate is measured from the receiving layer side of the thermal transfer image receiving sheet. In one embodiment, a reflection densitometer (RD-918, X-Rite) is used in the above measurement.

[0018] Each layer of the thermal transfer image receiving sheet of the present disclosure will be described in detail below. In the thermal transfer image receiving sheet of the present disclosure, it is preferable that the layers other than the Japanese paper base material have transparency to visible light in order to maintain the appearance of Japanese paper.

[0019] [Substrate] The substrate comprises at least a Japanese paper substrate.

[0020] In the present disclosure, the Japanese paper substrate includes Japanese paper (narrowly defined Japanese paper) obtained by hand-making using bast long fibers such as kozo, mitsumata, and gampi, and adding paste to the raw material, as well as Japanese paper (sometimes called washi-style or washi-like paper that has the texture of washi paper, as opposed to washi in the narrow sense) obtained by mechanically filtering various long fibers such as bast long fibers, hemp, kenaf, rayon, pulp, and synthetic fibers. The Japanese paper substrate can be obtained by using one or more of the above long fibers. In one embodiment, the length of the long fibers is 5 mm or more. Examples of synthetic polymers that constitute the synthetic fibers include polyamide, polyester, polyurethane, polyolefin, polyvinyl chloride, and polyvinyl alcohol. In the present disclosure, the Japanese paper substrate includes washi paper produced in Japan as well as washi paper produced outside Japan.

[0021] Specific examples of the Japanese paper base material include Unryu paper, Kozo paper, Mitsumata paper, Moro paper, Yuzen paper, Itajime paper, Tengujo paper, Kyoushi paper, Sarasa paper, Tairei paper, and Hosho paper.

[0022] The basis weight of the Japanese paper base material is preferably 5 g / m 2 More than 50g / m 2 Less than 6g / m, more preferably 2 More than 40g / m 2 Less than 8 g / m, more preferably 2 More than 35g / m 2 With such a configuration, for example, it is possible to impart the texture of Japanese paper to the thermal transfer image receiving sheet of the present disclosure.

[0023] The substrate may have a single layer structure consisting of only one Japanese paper substrate, a multilayer structure consisting of two or more Japanese paper substrates, or a multilayer structure consisting of a Japanese paper substrate and another layer. When the substrate has a multilayer structure, the number of layers in the multilayer structure is preferably 2 to 5, more preferably 2 to 4.

[0024] The substrate preferably comprises a transparent resin layer in addition to the Japanese paper substrate. That is, the substrate is preferably a laminate substrate of a Japanese paper substrate and a transparent resin layer. In this case, the substrate preferably comprises a transparent resin layer on the surface of the Japanese paper substrate on the receiving layer side. Since the surface of the Japanese paper substrate usually has irregularities, the surface of the receiving layer is also likely to have irregularities due to the irregularities, but such a configuration can improve, for example, the surface smoothness of the receiving layer, and therefore the printability on the receiving layer can be improved. Even in such a configuration, the Japanese paper substrate can be seen through from the receiving layer side in the thermal transfer image receiving sheet. The laminate substrate can be produced, for example, by utilizing the dry lamination method, the wet lamination method, and the extrusion method.

[0025] The resin material constituting the transparent resin layer is not particularly limited as long as it is a resin material having transparency, and examples thereof include polyesters such as polyethylene terephthalate and polybutylene terephthalate, polyolefins such as polyethylene and polypropylene, vinyl resins such as polyvinyl chloride, polyvinyl acetate, vinyl chloride-vinyl acetate copolymer and ethylene-vinyl acetate copolymer, (meth)acrylic resins such as poly(meth)acrylic acid ester, polystyrene, polyamide, polycarbonate, and ionomer resins. Among these, polyesters are preferred, and polyethylene terephthalate is more preferred. The transparent resin layer can contain one or more types of resin materials.

[0026] In the present disclosure, "(meth)acrylic" includes both "acrylic" and "methacrylic." Also, "(meth)acrylate" includes both "acrylate" and "methacrylate."

[0027] The transparent resin layer may contain additives. Examples of additives include plasticizers, coloring inhibitors, surfactants, matting agents, deodorants, flame retardants, antistatic agents, friction reducers, slip agents, dispersants, UV absorbers, antioxidants, weather stabilizers, fillers, and colorants such as pigments and dyes. The transparent resin layer may contain one or more additives.

[0028] The transparent resin layer can be formed, for example, by dispersing or dissolving the above-mentioned materials in water or an appropriate organic solvent to prepare a coating liquid, applying the coating liquid to a layer on which the transparent resin layer is to be laminated, or the like, by a known coating means to form a coating film, and drying the coating film. Examples of the coating means include a roll coating method, a reverse roll coating method, a gravure coating method, a reverse gravure coating method, a bar coating method, and a rod coating method.

[0029] Examples of the organic solvent include alcohol solvents such as ethyl alcohol and isopropyl alcohol; ketone solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; ester solvents such as methyl acetate, ethyl acetate, and butyl acetate; hydrocarbon solvents such as n-hexane, cyclohexane, benzene, toluene, and xylene; halogenated hydrocarbon solvents such as methylene chloride and chloroform; ether solvents such as tetrahydrofuran; glycol solvents such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, ethylene glycol monoethyl ether acetate, and propylene glycol monomethyl ether acetate; nitrogen-containing solvents such as acetonitrile and N,N-dimethylformamide; and sulfur-containing solvents such as dimethyl sulfoxide. One or more organic solvents can be used.

[0030] The transparent resin layer is preferably a film made of the above-mentioned resin material (hereinafter also referred to as "transparent resin film". When the transparent resin layer is a transparent resin film, the surface smoothness of the receiving layer can be further improved.

[0031] The transparent resin film may be a stretched film or an unstretched film. From the viewpoint of mechanical strength, it is preferable to use a stretched film that is uniaxially or biaxially stretched as the transparent resin film.

[0032] From the viewpoint of mechanical strength, the thickness of the transparent resin layer is preferably 10 μm or more and 300 μm or less, more preferably 30 μm or more and 200 μm or less, and further preferably 50 μm or more and 100 μm or less.

[0033] When the substrate is a laminate substrate of a Japanese paper substrate and a transparent resin layer, the substrate preferably has an adhesive layer between the Japanese paper substrate and the transparent resin layer, which can improve the adhesion between the Japanese paper substrate and the transparent resin layer.

[0034] In one embodiment, the adhesive layer contains a resin material. The resin material is not particularly limited as long as it is a transparent resin material, and examples thereof include vinyl resins such as polyvinyl chloride, polyvinyl acetate, vinyl chloride-vinyl acetate copolymer, ethylene-vinyl acetate copolymer, polyvinyl alcohol and polyvinylpyrrolidone, polyvinyl acetals such as polyvinyl acetoacetal and polyvinyl butyral, polyolefins, polystyrene, polyesters, polyamides, polyethers, (meth)acrylic resins, polyol resins, and urethane resins. The adhesive layer can contain one or more types of resin materials. The adhesive layer may contain one or more of the above additives.

[0035] The thickness of the adhesive layer is, for example, not less than 0.5 μm and not more than 8 μm.

[0036] The adhesive layer can be formed, for example, by dispersing or dissolving the above-mentioned materials in water or a suitable organic solvent to prepare a coating liquid, applying the coating liquid to an arbitrary layer by the above-mentioned known coating means to form a coating film, and drying the coating film. In one embodiment, the adhesive layer can be formed by melt-extruding a resin composition containing the above-mentioned materials.

[0037] The adhesive layer can also be formed using a conventionally known adhesive. The adhesive may be any one of a one-component curing type, a two-component curing type, and a non-curing type. The adhesive may be a solventless adhesive or a solvent-based adhesive. The adhesive layer may be formed, for example, by a non-solvent lamination method or a dry lamination method.

[0038] Examples of adhesives include two-component curing urethane adhesives, polyester-based polyurethane adhesives, polyether-based polyurethane adhesives, (meth)acrylic adhesives, polyester-based adhesives, polyether-based adhesives, polyamide-based adhesives, epoxy-based adhesives, rubber-based adhesives, polyolefin-based adhesives, acid-modified polyolefin-based adhesives, polyvinyl acetate-based adhesives, and polyvinyl chloride-based adhesives.

[0039] [Back layer] The thermal transfer image receiving sheet of the present disclosure has a back layer containing a water-soluble polysaccharide on the surface of the substrate opposite to the receiving layer. With this configuration, for example, it is possible to suppress the falling off of fibers constituting the Japanese paper substrate while maintaining the feel of Japanese paper on the back side of the thermal transfer image receiving sheet, and therefore to suppress contamination (e.g., adhesion of fibers) of grip rollers and the like constituting a thermal transfer printer, and further to improve the transportability of the thermal transfer image receiving sheet. In one embodiment, the back layer constitutes the surface layer on the back side of the thermal transfer image receiving sheet.

[0040] The water-soluble polysaccharide refers to a polysaccharide that dissolves in pure water at 25°C at a concentration of 1% by mass or more. The water-soluble polysaccharides may be synthetic or natural.

[0041] Examples of water-soluble polysaccharides include water-soluble cellulose derivatives, xanthan gum, guar gum, pullulan, and carrageenan, and water-soluble cellulose derivatives are preferred.Water-soluble cellulose derivatives are preferably water-soluble cellulose ethers.Water-soluble cellulose ethers are substances in which at least a part of the hydroxyl groups contained in cellulose is ether-substituted, and are water-soluble.The degree of substitution (degree of etherification) in water-soluble cellulose ethers is not particularly limited as long as it is in a range that allows water solubility.

[0042] Examples of water-soluble cellulose ethers include carboxy-C ethers such as carboxymethyl cellulose. 1 ~C 3 -Alkyl cellulose or its salt; carboxy-C such as carboxymethyl hydroxyethyl cellulose 1 ~C 3 -Alkylhydroxy-C 1 ~C 3 -Alkyl cellulose or its salt; C such as methyl cellulose 1 ~C 3 -Alkyl cellulose; hydroxy-C such as hydroxyethyl cellulose and hydroxypropyl cellulose 1 ~C 3 -Alkyl cellulose; hydroxy-C such as hydroxyethyl methylcellulose and hydroxypropyl methylcellulose; 1 ~C 3 -Alkyl-C 1 ~C 3 Examples of the salts include alkali metal salts such as sodium salts and potassium salts, calcium salts, magnesium salts, and ammonium salts.

[0043] Among these, carboxymethylcellulose, sodium carboxymethylcellulose, methylcellulose, hydroxyethylcellulose and hydroxypropylcellulose are preferred.

[0044] The weight-average molecular weight of the water-soluble polysaccharide is preferably 10,000 or more and 2,000,000 or less, more preferably 15,000 or more and 1,000,000 or less, and even more preferably 50,000 or more and 500,000 or less. The weight-average molecular weight of the water-soluble polysaccharide is a value measured by gel permeation chromatography-light scattering method (GPC-LS) in terms of polystyrene. The back surface layer may contain one or more water-soluble polysaccharides.

[0045] The content of the water-soluble polysaccharide in the back surface layer is preferably 50% by mass or more, more preferably 60% by mass or more, even more preferably 70% by mass or more, and even more preferably 80% by mass or more. With such a configuration, the above-mentioned effects can be more clearly obtained. The back layer may contain one or more of the above additives.

[0046] In the thermal transfer image receiving sheet of the present disclosure, the back surface layer is preferably in direct contact with the Japanese paper substrate in the substrate. With this configuration, it is possible to further suppress the falling off of the fibers constituting the Japanese paper substrate while maintaining the texture of Japanese paper on the back surface side of the thermal transfer image receiving sheet. This is presumably because the water-soluble polysaccharide contained in the back surface layer also functions in part as a binder for the fibers constituting the Japanese paper substrate.

[0047] The thickness of the back layer is preferably 0.2 μm or more and 2.5 μm or less, more preferably 0.3 μm or more and 2.0 μm or less, and even more preferably 0.5 μm or more and 1.5 μm or less. If the thickness is equal to or more than the lower limit, the falling off of the fibers constituting the Japanese paper base material can be further suppressed. If the thickness is equal to or less than the upper limit, the texture of Japanese paper can be maintained on the back side of the thermal transfer image receiving sheet. The thickness of the back layer is the average value of the thicknesses at any 10 points in a scanning electron microscope photograph of the cross section of the thermal transfer image receiving sheet. The same applies to the thicknesses of the other layers.

[0048] The back surface layer can be formed, for example, by dissolving the above-mentioned materials in water to prepare a coating liquid, applying the coating liquid to a substrate (particularly a Japanese paper substrate) by the known coating means described above to form a coating film, and then drying the coating film.

[0049] [Receiving layer] The thermal transfer image receiving sheet of the present disclosure includes a receiving layer. The receiving layer is, for example, a layer that receives a sublimation dye transferred from a sublimation transfer color material layer (dye layer) included in the thermal transfer sheet and maintains the formed image. Since it is preferable that the receiving layer is transparent so that the Japanese paper substrate can be seen through from the receiving layer side in the thermal transfer image receiving sheet, it is preferable that the receiving layer is a transparent receiving layer.

[0050] In one embodiment, the receiving layer contains a resin material. The resin material is not limited as long as it is a resin material that is easily dyed with a dye and has transparency, and examples thereof include polyolefins such as polyethylene and polypropylene, vinyl resins such as polyvinyl chloride, polyvinyl acetate, vinyl chloride-vinyl acetate copolymer and ethylene-vinyl acetate copolymer, (meth)acrylic resins such as poly(meth)acrylic acid ester, polyesters such as polyethylene terephthalate and polybutylene terephthalate, polystyrene, polyamide, polycarbonate, ionomer resins, and cellulose resins. The receiving layer can contain one or more types of resin materials.

[0051] The content of the resin material in the receiving layer is preferably 70% by mass or more and 99% by mass or less, more preferably 80% by mass or more and 98% by mass or less, and even more preferably 90% by mass or more and 97% by mass or less.

[0052] In one embodiment, the receiving layer contains a release agent. This can improve the releasability between the thermal transfer image receiving sheet and the thermal transfer sheet, for example. Examples of the release agent include solid waxes such as polyethylene wax, amide wax, and Teflon (registered trademark) powder; fluorine-based or phosphate-based surfactants; silicone oils, and silicone resins.

[0053] The silicone oil is preferably a modified silicone oil such as a reactive silicone oil or a cured silicone oil. The modified silicone oil is preferably an amino-modified silicone, an epoxy-modified silicone, an aralkyl-modified silicone, an epoxy-aralkyl-modified silicone, an alcohol-modified silicone, a vinyl-modified silicone, or a urethane-modified silicone, and examples of the modified silicone oil include an amino-modified silicone, an epoxy-modified silicone, an aralkyl-modified silicone, and an epoxy-aralkyl-modified silicone. The receiving layer may contain one or more release agents.

[0054] The content of the release agent in the receiving layer is preferably 0.5% by mass to 20% by mass, more preferably 0.5% by mass to 10% by mass, which can improve the releasability between the thermal transfer image receiving sheet and the thermal transfer sheet while maintaining the transparency of the receiving layer, for example.

[0055] The receiving layer can contain one or more of the above additives.

[0056] The thickness of the receiving layer is preferably 0.5 μm or more and 20 μm or less, and more preferably 1 μm or more and 10 μm or less, which can, for example, further improve the density of the image formed on the receiving layer.

[0057] The receiving layer can be formed, for example, by dispersing or dissolving the above-mentioned materials in water or a suitable organic solvent to prepare a coating liquid, applying the coating liquid to the layer on which the receiving layer will be laminated by the known coating means described above to form a coating film, and drying the coating film.

[0058] [Primer layer] In one embodiment, the thermal transfer image receiving sheet of the present disclosure includes a primer layer between the transparent resin layer and the receiving layer. This can improve the adhesion between these layers. Since it is preferable that the primer layer is transparent so that the Japanese paper can be seen through from the receiving layer side of the thermal transfer image receiving sheet, it is preferable that the primer layer is transparent.

[0059] In one embodiment, the primer layer contains a resin material. The resin material is not particularly limited as long as it is a transparent resin material, and examples thereof include polyester, polycarbonate, urethane resin, (meth)acrylic resin, styrene resin, vinyl resin, and cellulose resin. The primer layer can contain one or more types of resin materials. The primer layer may contain one or more of the above additives.

[0060] The thickness of the primer layer is, for example, not less than 0.1 μm and not more than 3 μm.

[0061] The primer layer can be formed, for example, by dispersing or dissolving the above-mentioned materials in water or an appropriate organic solvent to prepare a coating liquid, applying the coating liquid to a transparent resin layer or the like by the above-mentioned known coating means to form a coating film, and drying the coating film.

[0062] [Printed matter] The print of the present disclosure is produced using the thermal transfer image receiving sheet, and includes the thermal transfer image receiving sheet and an image formed on a receiving layer of the thermal transfer image receiving sheet. The details of each layer are as described above.

[0063] The image formed on the receiving layer is not particularly limited and may be a letter, a pattern, a symbol, a combination thereof, etc. The image can be formed on the receiving layer by using a thermal transfer sheet for a conventionally known dye-sublimation type thermal transfer recording method or a melting type thermal transfer recording method, for example.

[0064] [Protective layer] In one embodiment, the print of the present disclosure includes a protective layer on a receiving layer on which an image is formed. The print 20 of one embodiment shown in Fig. 3 includes a back layer 12, a substrate 14, a receiving layer 16 on which an image (not shown) is formed, and a protective layer 22 in this order in the thickness direction.

[0065] In one embodiment, the protective layer contains a resin material. The resin material is not particularly limited as long as it is a transparent resin material, and examples thereof include (meth)acrylic resin, styrene resin, vinyl resin, polyolefin, polyester, polyamide, cellulose resin, a cured product of a thermosetting resin, and a cured product of an active energy ray curable resin. The protective layer can contain one or more types of resin materials.

[0066] Examples of the thermosetting resin include epoxy resins, melamine resins, guanamine resins, urea resins, unsaturated polyesters, thermosetting urethane resins, thermosetting (meth)acrylic resins, and aminoalkyd resins.

[0067] The active energy ray curable resin is a resin that is cured by irradiation with active energy rays. Examples of the active energy rays include electromagnetic waves such as ultraviolet rays (UV), X-rays, and gamma rays; and charged particle rays such as electron beams (EB), alpha rays, and ion rays. Examples of the active energy ray curable resin include polyfunctional (meth)acrylate monomers and polyfunctional (meth)acrylate oligomers.

[0068] The content of the resin material in the protective layer is preferably 50% by mass or more, more preferably 50% by mass or more and 95% by mass or less, which can improve, for example, the scratch resistance and storage stability of the image formed on the receiving layer. The protective layer may contain one or more of the above additives.

[0069] The thickness of the protective layer is preferably from 0.1 μm to 10 μm, more preferably from 0.5 μm to 5 μm, which can improve, for example, the scratch resistance and storage stability of the image formed on the receiving layer.

[0070] [Method for manufacturing printed matter] The method for producing a print of the present disclosure includes (1) a step of preparing the thermal transfer image receiving sheet of the present disclosure, and (2) a step of forming an image on a receiving layer of the thermal transfer image receiving sheet (image forming step). In one embodiment, the method for producing a print of the present disclosure includes (3) a step of forming a protective layer on the receiving layer on which the image is formed (protective layer forming step). The structure of the thermal transfer image receiving sheet has been described above, and therefore will not be described here.

[0071] Examples of the image forming method include a method using a thermal transfer sheet of a conventionally known sublimation type thermal transfer recording method or a melting type thermal transfer recording method. In the sublimation type thermal transfer recording method, a thermal transfer sheet having a sublimation transfer type color material layer containing a sublimation dye is used to transfer the sublimation dye to a receiving layer to form an image. In the melting type thermal transfer recording method, a thermal transfer sheet having a melting transfer type color material layer is used to transfer the melting transfer type color material layer onto a receiving layer to form an image. In addition, an image may be formed by combining these methods.

[0072] The protective layer can be formed by a conventional method, for example, by transferring a protective layer from a protective layer transfer sheet having a protective layer onto a receiving layer on which an image is formed. The protective layer may be formed by laminating a film for forming a protective layer onto the receiving layer via an adhesive layer or the like. Details of the protective layer are as described above. The protective layer transfer sheet may be a thermal transfer sheet having a protective layer in surface order with the color material layer.

[0073] Specifically, the image is formed by superimposing the thermal transfer sheet and the thermal transfer image receiving sheet of the present disclosure and applying heat from the back side of the thermal transfer sheet using a heating member such as a thermal head to transfer the sublimation dye contained in the sublimation transfer colorant layer to the receiving layer, or by transferring the melt transfer colorant layer onto the receiving layer.

[0074] Specifically, the protective layer is formed by superposing a thermal transfer image receiving sheet having an image formed on a receiving layer and the protective layer transfer sheet, and applying heat from the back side of the protective layer transfer sheet using a heating member such as a thermal head to transfer the protective layer onto the receiving layer.

[0075] The present disclosure relates to, for example, the following [1] to

[10] . [1] A thermal transfer image receiving sheet comprising a back layer, a substrate, and a receiving layer in that order, wherein the substrate comprises a Japanese paper substrate, the back layer contains a water-soluble polysaccharide, and when the thermal transfer image receiving sheet and a black reference plate having an ISO visual density of 1.81 are superimposed and the ISO visual density of the black reference plate is measured through the thermal transfer image receiving sheet from the thermal transfer image receiving sheet side, the value is 0.20 or more and 0.70 or less. [2] The thermal transfer image-receiving sheet according to the above [1], wherein the water-soluble polysaccharide is a water-soluble cellulose derivative. [3] The thermal transfer image-receiving sheet according to the above [2], wherein the water-soluble cellulose derivative is at least one selected from the group consisting of carboxymethyl cellulose and its salts, methyl cellulose, hydroxyethyl cellulose, and hydroxypropyl cellulose. [4] The thermal transfer image receiving sheet according to any one of the above [1] to [3], wherein the thickness of the back layer is from 0.2 μm to 2.5 μm. [5] The thermal transfer image receiving sheet according to any one of the above [1] to [4], wherein the substrate is a laminated substrate comprising a Japanese paper substrate and a transparent resin layer. [6] The thermal transfer image-receiving sheet according to any one of the above [1] to [5], wherein the back layer and the Japanese paper substrate are in direct contact with each other. [7] A method for producing a printed matter, comprising: (1) a step of preparing a thermal transfer image receiving sheet described in any one of [1] to [6] above; and (2) a step of forming an image on a receiving layer provided in the thermal transfer image receiving sheet. [8](3) A method for producing a printed matter according to the above [7], further comprising the step of forming a protective layer on the receiving layer on which the image has been formed. [9] A printed matter comprising the thermal transfer image receiving sheet according to any one of the above [1] to [6] and an image formed on a receiving layer of the thermal transfer image receiving sheet.

[10] The print according to [9] above, further comprising a protective layer on the receiving layer on which the image is formed. EXAMPLES

[0076] The thermal transfer image receiving sheet and the like of the present disclosure will be described in more detail below based on examples, but the thermal transfer image receiving sheet and the like of the present disclosure are not limited to these examples. In the following description, "parts" means "parts by mass."

[0077] [Example 1] Washi paper (Sanwa Paper Co., Ltd., Product number: C401, Product name: Rayon Unryu (with pulp), Basis weight: 9g / m 2 ) was coated with and dried on one side of a transparent polyethylene terephthalate (PET) film (Mitsubishi Chemical Corporation, Diafoil (registered trademark) S100-75, thickness 75 μm) to form a 1 μm thick back layer. A primer layer coating liquid of the following composition was coated and dried on one side of a transparent polyethylene terephthalate (PET) film (Mitsubishi Chemical Corporation, Diafoil (registered trademark) S100-75, thickness 75 μm) to form a 1 μm thick transparent primer layer (transparent Pr layer). A receiving layer coating liquid of the following composition was coated and dried on the transparent Pr layer to form a receiving layer of 4 μm in thickness. In this way, a laminate consisting of a transparent PET film / transparent Pr layer / receiving layer was obtained. A coating liquid for an adhesive layer of the following composition was coated and dried on the other side of the transparent PET film to form an adhesive layer of 2.5 μm in thickness. The above-mentioned Japanese paper on which a back layer was formed was attached to the adhesive layer on the above-mentioned laminate to obtain a thermal transfer image receiving sheet.

[0078] [Coating liquid A for back layer] Sodium carboxymethylcellulose 5 parts (CMC Daicel (registered trademark), Daicel Miraize Co., Ltd.) ·Wednesday 95 parts

[0079] [Coating liquid for primer layer] Polyester (solid content: 25% by weight) 40 parts (Vylonal (registered trademark) MD-1480, Toyobo Co., Ltd.) Filler 9 parts (Laponite JS, Wilper-Ellis Co., Ltd.) Surfactant 0.08 parts (Dinol 604, Nissin Chemical Industry Co., Ltd.) 60 parts isopropyl alcohol ·Wednesday 120 copies

[0080] [Coating liquid for receiving layer] Vinyl chloride-vinyl acetate copolymer 12 parts (Solvine (registered trademark) C, Nissin Chemical Industry Co., Ltd.) Epoxy modified silicone 0.8 parts (X-22-3000T, Shin-Etsu Chemical Co., Ltd.) Amino modified silicone 0.24 parts (X-22-1660B-3, Shin-Etsu Chemical Co., Ltd.) Toluene 30 parts Methyl ethyl ketone 30 parts

[0081] [Coating liquid for adhesive layer] Multifunctional polyol 30 parts (Takelac® A-969V, Mitsui Chemicals, Inc.) Isocyanate hardener 10 parts (Takenate (registered trademark) A-5, Mitsui Chemicals, Inc.) 60 parts ethyl acetate

[0082] [Examples 2 to 5, Comparative Examples 1 to 7] A thermal transfer image receiving sheet was obtained in the same manner as in Example 1, except that the configuration of each layer of the thermal transfer image receiving sheet was changed as shown in Table 1. Details of the back layer coating liquid used and the product are described below. In Table 1, the back layer formed using back layer coating liquid A is described as "back layer A". The same applies to back layer coating liquids B to E.

[0083] [Coating liquid B for back layer] Methylcellulose 5 parts (Metolose (registered trademark) SM-15, Shin-Etsu Chemical Co., Ltd.) ·Wednesday 95 parts

[0084] [Coating liquid C for back layer] Hydroxyethylcellulose 5 parts (HEC Daicel (registered trademark) SP200, Daicel Miraize Co., Ltd.) ·Wednesday 95 parts

[0085] [Coating liquid D for back layer] Hydroxypropyl cellulose 5 parts (HPC-SL, Nippon Soda Co., Ltd.) ·Wednesday 95 parts

[0086] [Coating liquid E for back layer] Cellulose acetate 5 parts (L-20, Daicel Corporation) Methyl ethyl ketone 95 parts

[0087] Japanese paper 1: Sanwa Paper Co., Ltd., Part number: C401, Product name: Rayon Unryu (with pulp), Basis weight: 9g / m 2 Japanese paper 2: Sanwa Paper Co., Ltd., Part number: A403, Product name: Rayon Unryu, Basis weight: 30g / m 2 Utrillo Coat: Utrillo (registered trademark) coated (A2), general paper, Basis weight 84.9g / m 2 , Daio Paper Corporation Transparent PET: Transparent polyethylene terephthalate film, Mitsubishi Chemical Corporation, Diafoil (registered trademark) S100-75, thickness 75 μm White PET: White polyethylene terephthalate film, Toyobo Co., Ltd. FK202, thickness 75μm,

[0088] [Evaluation] [Transparency] The thermal transfer image-receiving sheets obtained in the Examples and Comparative Examples were visually observed from the receiving layer side, and the transparency was evaluated based on the following evaluation criteria. A: It is transparent and has a high design quality. NG: Almost no transparency and poor design.

[0089] [Appearance evaluation] The thermal transfer image-receiving sheets obtained in the Examples and Comparative Examples were visually observed from the receiving layer side, and the appearance was evaluated based on the following evaluation criteria. A: The appearance is similar to Japanese paper. ·NG: The appearance is not like washi paper.

[0090] [ISO visual density] The thermal transfer image receiving sheets obtained in the Examples and Comparative Examples were overlapped with a black calibration plate (black reference plate) of a reflection densitometer (RD-918, X-Rite Co.) so that the black calibration plate and the back side of the thermal transfer image receiving sheet were in contact with each other, and the reflection density (ISO visual density) of the black calibration plate was measured from the receiving layer side of the thermal transfer image receiving sheet using a reflection densitometer (RD-918, X-Rite Co.). The reflection density of the black calibration plate (the reflection density of the black calibration plate alone) before overlapping with the thermal transfer image receiving sheet was 1.81.

[0091] [Evaluation of feel] The thermal transfer image receiving sheets obtained in the Examples and Comparative Examples were evaluated for feel when touching the back side (the side opposite to the receiving layer) based on the following evaluation criteria. A: It has the feel of Japanese paper. NG: It doesn't have the feel of washi paper.

[0092] [Evaluation of printer transportability] The thermal transfer image receiving sheets obtained in the Examples and Comparative Examples were combined with a dye-sublimation thermal transfer printer DS620 (Dai Nippon Printing Co., Ltd.) and the original thermal transfer sheet for that printer to print 50 sheets, and the prints were visually checked for any registration misalignment, and the transportability was evaluated based on the following evaluation criteria. Registration misalignment is a print position shift caused by insufficient transportability, and refers to a state in which the image receiving sheet after printing on the Y panel or M panel is not transported to the correct position, causing a shift in the image and significantly deteriorating the print quality. Furthermore, the absence of registration misalignment means that the transportability is good. A: There was no misregistration in the printed matter. NG: There is misregistration in the printed matter.

[0093] [Contamination of gripper roller] The thermal transfer image receiving sheets obtained in the Examples and Comparative Examples were combined with a dye-sublimation thermal transfer printer DS620 (Dai Nippon Printing Co., Ltd.) and the printer's original thermal transfer sheet to print 50 sheets. At this time, the contamination of the grip roller was evaluated based on the following evaluation criteria. A: No dirt caused by the fibers of the washi paper is found on the grip roller. NG: There is a lot of dirt on the grip roller caused by the fibers of the washi paper.

[0094] [Fiber shedding] The thermal transfer image receiving sheets obtained in the Examples and Comparative Examples were combined with a dye-sublimation thermal transfer printer DS620 (Dai Nippon Printing Co., Ltd.) and the printer's original thermal transfer sheet to print 50 sheets. During this process, fiber loss was evaluated based on the following evaluation criteria. A: No fiber loss observed. NG: Fiber loss is observed.

[0095] [Table 1] [Explanation of symbols]

[0096] 10: Thermal transfer image receiving sheet 12: Back layer 14: Base material 14-1: Washi paper base material 14-2: Adhesive layer 14-3: Transparent resin layer 16: Receptive layer 20: Prints 22:Protective layer

Claims

1. A thermal transfer image receiving sheet comprising a back layer, a substrate, and a receiving layer in this order, The substrate comprises a Japanese paper substrate; The back surface layer contains a water-soluble polysaccharide, the thermal transfer image receiving sheet and a black reference plate having an ISO visual density of 1.81 are superimposed on each other, and the ISO visual density of the black reference plate is measured from the thermal transfer image receiving sheet side through the thermal transfer image receiving sheet, and the measured value is 0.20 or more and 0.70 or less; Thermal transfer image receiving sheet.

2. 2. The thermal transfer image-receiving sheet according to claim 1, wherein the water-soluble polysaccharide is a water-soluble cellulose derivative.

3. 3. The thermal transfer image-receiving sheet according to claim 2, wherein the water-soluble cellulose derivative is at least one selected from the group consisting of carboxymethyl cellulose and its salts, methyl cellulose, hydroxyethyl cellulose, and hydroxypropyl cellulose.

4. 4. The thermal transfer image receiving sheet according to claim 1, wherein the thickness of the back surface layer is from 0.2 μm to 2.5 μm.

5. 5. The thermal transfer image receiving sheet according to claim 1, wherein the substrate is a laminated substrate comprising the Japanese paper substrate and a transparent resin layer.

6. The thermal transfer image receiving sheet according to any one of claims 1 to 5, wherein the back surface layer and the Japanese paper substrate are in direct contact with each other.

7. (1) preparing a thermal transfer image receiving sheet according to any one of claims 1 to 6; (2) forming an image on the receiving layer of the thermal transfer image receiving sheet; A method for producing a printed matter comprising the steps of:

8. (3) A step of forming a protective layer on the receiving layer on which the image is formed. The method for producing a print according to claim 7, further comprising:

9. A thermal transfer image receiving sheet according to any one of claims 1 to 6, An image formed on the receiving layer of the thermal transfer image receiving sheet; A printed matter that has the above features.

10. The print according to claim 9 , further comprising a protective layer on the receiving layer on which the image is formed.

Images