Thermal transfer sheet and method for manufacturing printed matter

Abstract

To provide a thermal transfer sheet with which it is possible to transfer a protective layer twice or more on an identical transferred object, and it is possible to prevent occurrence of a print wrinkle on an obtained printed matter.SOLUTION: A thermal transfer sheet includes a base material, at least one color material layer, and a transferable protective layer. The color material layer and the protective layer are disposed in a frame sequential manner on one surface of the base material. A length of the protective layer is greater than or equal to twice a screen length of the color material layer. A coefficient of dynamic friction between a surface opposite to the base material in the protective layer and a surface closer to the base material in the protective layer is 0.34-0.85.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] Conventionally, a thermal transfer method has been used as a simple printing method. In the thermal transfer method, a thermal transfer sheet having a colorant layer provided on one side of a substrate and a thermal transfer image-receiving sheet having an image-receiving layer provided as needed are superimposed, and the back side of the thermal transfer sheet is heated in an imagewise manner using a heating means such as a thermal head to form an image (thermal transfer image) on the thermal transfer image-receiving sheet.

[0003] Thermal transfer methods are divided into a melt transfer method and a sublimation transfer method. Images formed by the thermal transfer method have high density and excellent sharpness. Therefore, the thermal transfer method is suitable for recording binary images such as characters. The sublimation transfer method can control the amount of sublimation dye migration depending on the amount of energy applied, so it can form gradation images with controlled image density for each dot of the thermal head. The sublimation transfer method uses a thermal transfer sheet with different colored dye layers, such as yellow, magenta, cyan, and black, and transfers each color dye onto a thermal transfer image-receiving sheet, making it possible to form high-quality, photographic-like full-color images with excellent intermediate color reproducibility.

[0004] However, the formed image may have poor durability. To solve this problem, it has been proposed to use a thermal transfer sheet having a substrate and a protective layer provided so as to be peelable from the substrate, and to transfer the protective layer onto the image (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-238525 Summary of the Invention [Problem to be solved by the invention]

[0006] From the viewpoint of further improving the durability of the print by the protective layer, the present inventors have investigated the idea of thermally transferring a protective layer so as to at least cover the thermally transferred image, and then transferring another protective layer onto the transferred protective layer, i.e., transferring a protective layer onto the thermally transferred image two or more times. However, the present inventors have found that transferring another protective layer onto the transferred protective layer may cause print wrinkles in the resulting print.

[0007] An object of the present disclosure is to provide a thermal transfer sheet that can transfer a protective layer onto the same transfer recipient two or more times, and that can suppress the occurrence of print wrinkles in the resulting print. [Means for solving the problem]

[0008] The thermal transfer sheet of the present disclosure comprises a substrate, at least one colorant layer, and a transferable protective layer, the colorant layer and the protective layer being arranged in face-sequential order on one side of the substrate, the length of the protective layer being at least twice the screen length of the colorant layer, and the dynamic friction coefficient between the surface of the protective layer opposite the substrate and the surface of the protective layer facing the substrate is 0.34 or more and 0.85 or less. [Effects of the Invention]

[0009] According to the present disclosure, it is possible to provide a thermal transfer sheet that can transfer a protective layer onto the same transfer-receiving material two or more times, and that can suppress the occurrence of print wrinkles in the resulting print. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic cross-sectional view of a thermal transfer sheet according to one embodiment of the present disclosure. [Figure 2] FIG. 2 is a schematic cross-sectional view of a thermal transfer sheet according to one embodiment of the present disclosure. [Figure 3]FIG. 3 is a schematic cross-sectional view showing an example of a printed matter in a state where a protective layer is transferred onto a transfer-receiving body using a thermal transfer sheet according to an embodiment of the present disclosure. [Figure 4] FIG. 4 is a schematic cross-sectional view showing an example of a printed matter in a state where a protective layer is transferred onto a transfer-receiving body using a thermal transfer sheet according to an embodiment of the present disclosure. [Figure 5] FIG. 5 is a schematic top view of a thermal transfer sheet according to one embodiment of the present disclosure. [Figure 6] FIG. 6 is a schematic top view of a thermal transfer sheet according to one embodiment of the present disclosure. [Figure 7] FIG. 7 is a schematic cross-sectional view of a thermal transfer sheet according to one embodiment of the present disclosure. [Figure 8] FIG. 8 is a schematic top view of a thermal transfer sheet according to one embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of the present disclosure will be described in detail. The present disclosure can be implemented in many different forms, and should not be construed as being limited to the description of the embodiments exemplified below. For clarity of explanation, the drawings may show the width, thickness, shape, etc. of each layer more schematically than in the embodiments, but these are merely examples and do not limit the interpretation of the present disclosure. In this specification and each drawing, elements similar to those already described with reference to the previous drawings are designated by the same reference numerals, and detailed descriptions may be omitted as appropriate.

[0012] [Thermal transfer sheet] The thermal transfer sheet of the present disclosure comprises: a substrate, at least one colorant layer, and a transferable protective layer; Equipped with. The colorant layer and the transferable protective layer are provided in surface order on one surface of the substrate.

[0013] The term "transferable protective layer" refers to a protective layer that is peeled from the substrate and transferred onto a transfer-receiving material by applying energy such as thermal energy to the back surface of the thermal transfer sheet. In other words, the transferable protective layer constitutes a transfer layer in the thermal transfer sheet that can be peeled off by the application of energy. Hereinafter, the transferable protective layer will also be simply referred to as "protective layer."

[0014] In one embodiment, the protective layer comprises a release layer and an adhesive layer from the substrate side. That is, in one embodiment, the protective layer comprises a release layer and an adhesive layer provided on the surface of the release layer opposite the substrate. In one embodiment, the adhesive layer comes into contact with the transfer recipient when the protective layer is transferred onto the transfer recipient for the first time. In one embodiment, the release layer constitutes the surface layer of the print obtained when the protective layer is transferred onto the transfer recipient for, for example, the second time.

[0015] The thermal transfer sheet 1 of the embodiment shown in FIG. 1 comprises a substrate 10, a colorant layer 30 and a protective layer 20 provided in face-sequential order on one side of the substrate 10, and a back layer 40 provided on the other side of the substrate 10. The thermal transfer sheet 1 of the embodiment shown in FIG. 2 is similar to the thermal transfer sheet 1 of the embodiment shown in FIG. 1, except that the protective layer 20 comprises a release layer 22 and an adhesive layer 24. The thermal transfer sheet 1 of the embodiment shown in FIGS. 1 and 2 may further comprise a release layer (not shown) located between the substrate 10 and the protective layer 20. The back layer 40 may be omitted from the thermal transfer sheet 1 of the embodiment shown in FIGS. 1 and 2.

[0016] 1 and 2, an image is formed on a transferee 50 using the thermal transfer sheet 1, and then a protective layer 20 is transferred twice onto the image, resulting in a printed matter 2 that includes the transferee 50, an image (not shown) formed on the transferee 50, and two protective layers 20, 20 provided on the transferee 50 so as to cover the image, as shown in Figures 3 and 4, respectively. The protective layer 20 can provide good protection for the image (not shown) and other elements provided on the printed matter 2.

[0017] A combination of at least one colorant layer and a protective layer provided face-sequentially on the colorant layer is referred to as a "unit" (U). The thermal transfer sheet of the present disclosure may have one unit repeated on one side of a long substrate, i.e., multiple units provided face-sequentially in the longitudinal direction of the substrate. Figure 5 shows a top view of a thermal transfer sheet of one embodiment. In the thermal transfer sheet 1 of the embodiment shown in Figure 5, multiple units (U) each consisting of a colorant layer 30 and a protective layer 20 are provided face-sequentially in the longitudinal direction of the substrate.

[0018] In the thermal transfer sheet of the present disclosure, the length of the protective layer is at least twice the screen length of the color material layer. "Screen length of the color material layer" refers to the length L1 of one color material layer 30 in the longitudinal direction (flow direction) of the thermal transfer sheet 1 when viewed in a plane as shown in Figure 5. "Length of the protective layer" refers to the length L2 of the protective layer 20 in the longitudinal direction (flow direction) of the thermal transfer sheet 1 when viewed in a plane as shown in Figure 5. "Screen size" refers to the area of one color material layer 30 in the thermal transfer sheet 1.

[0019] The length of the protective layer is at least twice the screen length of the colorant layer, preferably at least 2 times and no more than 10 times, more preferably at least 2 times and no more than 5 times, and even more preferably at least 2 times and no more than 3 times. In one embodiment of the thermal transfer sheet of the present disclosure, the size (area) of one protective layer is at least twice the screen size, preferably at least 2 times and no more than 10 times, more preferably at least 2 times and no more than 5 times, and even more preferably at least 2 times and no more than 3 times. In other words, the thermal transfer sheet of the present disclosure can transfer at least two screen-sized protective layers. This allows the same thermal transfer sheet to be used to transfer a protective layer onto the same thermal transfer image on a transfer recipient more than once.

[0020] In one embodiment, the protective layer has at least a first region and a second region. The lengths of the first region and the second region are each equal to or greater than the screen length of the color material layer. In one embodiment, the areas of one color material layer, the protective layer in the first region, and the protective layer in the second region are approximately the same and are the same size as the entire surface (screen size) of the transfer target object to be transferred.

[0021] In the protective layer, the first and second regions are positioned in frame sequence. The first and second regions may be continuous. That is, there may be no other region between the first and second regions, and the first and second regions may be virtual regions, with no boundary separating them. In the thermal transfer sheet 1 of the embodiment shown in FIG. 6, the shaded region indicated by reference numeral 20a is the first region, and the shaded region indicated by reference numeral 20b is the second region. In the thermal transfer sheet 1 of the embodiment shown in FIG. 6, one protective layer 20 consists of a first region 20a and a second region 20b. A protective layer including the first and second regions may be formed using a single protective layer coating liquid.

[0022] If the length of the protective layer is three times or more the screen length of the colorant layer, the protective layer may further have a third region, in which case the protective layer can be transferred onto the same transfer target three or more times using the same thermal transfer sheet.

[0023] In an image forming method using a thermal transfer sheet, a colorant layer of the thermal transfer sheet is thermally transferred to a transfer recipient to form an image, and a protective layer is thermally transferred from the thermal transfer sheet onto the image so as to cover at least the printed portion. By using the thermal transfer sheet of the present disclosure, the protective layer can be transferred to the same transfer recipient two or more times. That is, two or more protective layers can be laminated on the same image. This allows for the production of a thermally transferred image with excellent durability in various respects, even under harsh usage conditions, and also suppresses the occurrence of wrinkles in the print, as described below.

[0024] <Base material> The substrate can be any material without particular restrictions as long as it has heat resistance sufficient to withstand the thermal energy used when transferring the protective layer from the thermal transfer sheet onto the transfer recipient, and mechanical strength and solvent resistance sufficient to support the protective layer.

[0025] Examples of the substrate include resin films made of resin materials, such as polyesters such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), polyethylene terephthalate-isophthalate copolymer, and terephthalic acid-cyclohexanedimethanol-ethylene glycol copolymer; polyamides such as nylon 6 and nylon 6,6; polyolefins such as polyethylene, polypropylene, and polymethylpentene; vinyl resins such as polyvinyl chloride and vinyl chloride-vinyl acetate copolymer; (meth)acrylic resins such as poly(meth)acrylate and polymethyl(meth)acrylate; polyimides; polycarbonates; engineering resins such as polyarylate, polysulfone, polyethersulfone, polyphenylene ether, polyphenylene sulfide, polyaramid, polyetherketone, and polyetheretherketone; styrene resins such as polystyrene, high-impact polystyrene, acrylonitrile-styrene copolymer, and acrylonitrile-butadiene-styrene copolymer; and cellulose resins such as cellophane, cellulose acetate, and nitrocellulose. Among resin films, resin films made of polyesters such as PET and PEN are preferred from the viewpoint of excellent heat resistance and mechanical strength. The resin film can contain one or more types of resin materials.

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

[0027] The substrate may be, for example, a paper substrate such as glassine paper, condenser paper, and paraffin paper.

[0028] The substrate may be a laminate having multiple layers. For example, a resin film laminate may be used as the substrate. The resin film laminate can be produced by, for example, dry lamination, wet lamination, or extrusion. The substrate may be a stretched film or an unstretched film, or may be a film stretched uniaxially or biaxially from the viewpoint of improving strength. In one embodiment, the substrate is elongated.

[0029] The thickness of the substrate is preferably 0.5 μm to 50 μm, more preferably 1 μm to 20 μm, and even more preferably 1 μm to 10 μm, which can improve the balance between the mechanical strength and the transferability of the protective layer, for example.

[0030] <Protective layer> The protective layer is a layer that protects the surface of the transferee after it is transferred from the thermal transfer sheet to the transferee. In the thermal transfer sheet of the present disclosure, the surface of the protective layer facing the substrate is referred to as the first surface, and the surface of the protective layer opposite the substrate is referred to as the second surface. That is, the protective layer has a first surface and a second surface opposite the first surface. In Figures 1 and 2, the first surface is designated by the reference numeral 26, and the second surface is designated by the reference numeral 28. In one embodiment, when the protective layer includes a release layer and an adhesive layer, the release layer constitutes the first surface, and the adhesive layer constitutes the second surface.

[0031] The thermal transfer sheet of the present disclosure is characterized in that the coefficient of dynamic friction between the surface of the protective layer opposite the substrate (second surface) and the surface of the protective layer facing the substrate (first surface) is 0.34 or more and 0.85 or less. The coefficient of dynamic friction is preferably 0.34 or more and 0.60 or less. This can prevent wrinkles from occurring in the resulting print, for example, when the protective layer is thermally transferred to a transfer target object two or more times.

[0032] In this disclosure, the "dynamic friction coefficient" is measured in accordance with JIS K7125:1999 "Plastics - Films and Sheets - Friction Coefficient Test Method." The measurement conditions for the dynamic friction coefficient are: sliding piece load: 1.96 N, sliding piece contact area: 22 cm 2 Test speed: 1000mm / min.

[0033] The dynamic friction coefficient is measured as follows: First, the protective layer in the first region is transferred from the thermal transfer sheet onto a transfer-receiving body. Next, the second surface of the protective layer in the second region of the thermal transfer sheet is placed face-to-face with the first surface of the protective layer in the first region transferred onto the transfer-receiving body, and the dynamic friction coefficient is measured under the above-mentioned measurement conditions.

[0034] The transfer conditions are as follows: The protective layer is transferred onto a polyvinyl chloride (PVC) card (standard white card, manufactured by Dai Nippon Printing Co., Ltd.) using the thermal transfer sheet and a card printer SD360 (Enrast) with an energy setting of ±0.

[0035] (peeling layer) In one embodiment, the protective layer includes a release layer, which is the layer that is located closest to the substrate among the layers that make up the protective layer. The provision of the release layer can further improve the transferability of the protective layer. The release layer is transferred as part of the protective layer during thermal transfer, and after the final transfer of the protective layer, the release layer becomes the surface layer of the thermally transferred image, improving the abrasion resistance of the thermally transferred image.

[0036] The release layer, in one embodiment, contains a binder. Examples of binders include resin materials, such as (meth)acrylic resins, styrene resins, vinyl resins such as polyvinyl alcohol, polyvinyl acetate, polyvinyl chloride, vinyl chloride-vinyl acetate copolymers, polyvinyl butyral, polyvinyl acetal, and polyvinyl pyrrolidone, polyesters such as polyethylene terephthalate and polyethylene naphthalate, cellulose resins such as ethyl cellulose, hydroxyethyl cellulose, ethylhydroxycellulose, methyl cellulose, and cellulose acetate, polyamides, polyurethanes, polycarbonates, phenoxy resins, epoxy resins, silicone-modified versions of these resins, ultraviolet-absorbing resins, and ionizing radiation-curable resins.

[0037] In one embodiment, the release layer contains a (meth)acrylic resin. Examples of the (meth)acrylic resin include a polymer of (meth)acrylic acid, a polymer of a (meth)acrylic acid ester, a copolymer of (meth)acrylic acid and another monomer, and a copolymer of a (meth)acrylic acid ester and another monomer. Specific examples of the (meth)acrylic resin include polymethyl(meth)acrylate, polyethyl(meth)acrylate, polypropyl(meth)acrylate, polybutyl(meth)acrylate, polyisobutyl(meth)acrylate, an ethyl(meth)acrylate-methyl(meth)acrylate copolymer, a butyl(meth)acrylate-methyl(meth)acrylate copolymer, an ethylene-methyl(meth)acrylate copolymer, and a styrene-methyl(meth)acrylate copolymer. The release layer can contain one or more (meth)acrylic resins.

[0038] The weight average molecular weight (Mw) of the (meth)acrylic resin is preferably 5,000 or more and 300,000 or less, more preferably 10,000 or more and 150,000 or less, even more preferably 15,000 or more and 100,000 or less, and particularly preferably 20,000 or more and 80,000 or less. In the present disclosure, Mw is measured by gel permeation chromatography (GPC) in accordance with JIS K7252-1 using polystyrene as a standard substance.

[0039] The glass transition temperature (Tg) of the (meth)acrylic resin is preferably 30° C. or higher and 120° C. or lower, more preferably 40° C. or higher and 120° C. or lower, and even more preferably 50° C. or higher and 120° C. or lower. In the present disclosure, Tg is obtained by differential scanning calorimetry (DSC) in accordance with JIS K7121.

[0040] Examples of ionizing radiation curable resins include resins obtained by crosslinking and curing a radical polymerizable polymer or a radical polymerizable oligomer by irradiating it with ionizing radiation. Specific examples include resins obtained by adding a photopolymerization initiator to a radical polymerizable polymer or a radical polymerizable oligomer as needed, and polymerizing and crosslinking the resulting polymer or oligomer by irradiating it with an electron beam or ultraviolet light.

[0041] The release layer may contain one or more binders. The content of the binder in the release layer is preferably 80% by mass or more, more preferably 85% by mass or more, based on the total mass of the release layer, which can impart sufficient durability to the release layer, for example.

[0042] The release layer may contain a lubricant, which, for example, can set the dynamic friction coefficient lower, thereby maintaining good running properties of the thermal transfer sheet when transferring the protective layer for the second time, and suppressing the occurrence of wrinkles in the resulting print.

[0043] Examples of lubricants include waxes; metal salts of higher fatty acids; organic particles such as (meth)acrylic resins, crosslinked polystyrene, and fluororesins (e.g., polytetrafluoroethylene); and inorganic particles such as silica, clay, talc, titanium oxide, calcium carbonate, and barium sulfate.

[0044] Examples of waxes include synthetic waxes such as paraffin wax, microcrystalline wax, silicone wax, oxidized wax, ozokerite, ceresin, polyester wax, and polyethylene wax; natural waxes such as beeswax, spermaceti, Japan wax, rice bran wax, carnauba wax, candelilla wax, and montan wax; higher saturated fatty acids such as margaric acid, lauric acid, myristic acid, palmitic acid, stearic acid, furoic acid, and behenic acid; higher saturated monohydric alcohols such as stearyl alcohol and behenyl alcohol; higher fatty acid esters such as sorbitan fatty acid esters; and higher fatty acid amides such as stearic acid amide and oleic acid amide. Examples of metal salts of higher fatty acids include zinc stearate, zinc stearyl phosphate, calcium stearate, and magnesium stearate.

[0045] The average particle size of the lubricant, such as particles, is preferably 0.5 μm or more and 10 μm or less, more preferably 0.5 μm or more and 5 μm or less. This allows, for example, the above-mentioned dynamic friction coefficient to be set lower. The average particle size of the lubricant means the volume average particle size and is measured in accordance with JIS Z8819-2:2019.

[0046] The release layer may contain one or more lubricants. The content of the lubricant in the release layer may be, for example, 1% by mass to 20% by mass, or 2% by mass to 15% by mass, relative to the total mass of the release layer, which allows, for example, the effect of the lubricant to be exerted while ensuring transparency.

[0047] The release layer may contain an additive, such as a benzophenone-based ultraviolet absorber, a benzotriazole-based ultraviolet absorber, a benzoate-based ultraviolet absorber, a triazine-based ultraviolet absorber, titanium oxide, or zinc oxide; a light stabilizer such as a hindered amine-based light stabilizer or a Ni chelate-based light stabilizer; or an antioxidant such as a hindered phenol-based antioxidant, a sulfur-based antioxidant, a phosphorus-based antioxidant, or a lactone-based antioxidant.

[0048] The release layer may contain one or more additives. The content of the additive in the release layer may be, for example, 20% by mass or less, or 15% by mass or less, relative to the total mass of the release layer.

[0049] The thickness of the release layer is preferably 0.1 μm to 20 μm, more preferably 0.3 μm to 10 μm, and even more preferably 0.5 μm to 3 μm, which can, for example, prevent transfer defects of the protective layer and provide a sufficient protective function to the transfer target.

[0050] The release layer can be formed, for example, by applying a coating liquid containing the above-mentioned materials to the substrate or the release layer by known means such as roll coating, reverse roll coating, gravure coating, reverse gravure coating, bar coating, and rod coating, and then drying the coating.

[0051] (adhesive layer) In one embodiment, the protective layer includes an adhesive layer provided on the surface of the release layer opposite the substrate. The adhesive layer is a layer that improves adhesion between the protective layer and the transfer target. The adhesive layer can be formed, for example, from a conventionally known pressure-sensitive adhesive or heat-sensitive adhesive.

[0052] In one embodiment, the adhesive layer contains a resin material. Examples of resin materials include vinyl resins such as polyvinyl chloride, polyvinyl acetate, and vinyl chloride-vinyl acetate copolymers, (meth)acrylic resins, acid-modified polyolefins such as α-olefin-maleic anhydride copolymers, polyesters, polyurethanes, cellulose resins, silicone resins, fluororesins, and various resins modified with silicone or fluorine. Among these, vinyl chloride-vinyl acetate copolymers, polyesters, and (meth)acrylic resins are more preferred, and vinyl chloride-vinyl acetate copolymers and polyesters are even more preferred.

[0053] The glass transition temperature (Tg) of the resin material contained in the adhesive layer is preferably 40° C. or higher and 90° C. or lower, more preferably 50° C. or higher and 80° C. or lower, and even more preferably 55° C. or higher and 75° C. or lower, which can further improve, for example, printing performance.

[0054] The vinyl chloride-vinyl acetate copolymer refers to a copolymer having structural units derived from vinyl chloride and structural units derived from vinyl acetate, but the copolymer may also have structural units derived from compounds other than vinyl chloride and vinyl acetate.

[0055] The content of structural units derived from vinyl chloride in a vinyl chloride-vinyl acetate copolymer may be, for example, 10% by mass to 90% by mass, 30% by mass to 90% by mass, or 50% by mass to 90% by mass. The content of structural units derived from vinyl acetate in a vinyl chloride-vinyl acetate copolymer may be, for example, 10% by mass to 90% by mass, 10% by mass to 70% by mass, or 10% by mass to 50% by mass.

[0056] Examples of compounds other than vinyl chloride and vinyl acetate include vinyl monomers other than vinyl chloride and vinyl acetate. The content of structural units derived from compounds other than vinyl chloride and vinyl acetate in the vinyl chloride-vinyl acetate copolymer may be 8% by mass or less, 5% by mass or less, or 3% by mass or less.

[0057] The weight average molecular weight (Mw) of the vinyl chloride-vinyl acetate copolymer may be, for example, 5,000 or more and 80,000 or less, or 10,000 or more and 70,000 or less.

[0058] The polyester means a copolymer of a dicarboxylic acid compound and a diol compound. Examples of dicarboxylic acid compounds include malonic acid, succinic acid, glutaric acid, adipic acid, suberic acid, sebacic acid, dodecanedioic acid, eicosanedioic acid, pimelic acid, azelaic acid, methylmalonic acid, ethylmalonic acid, adamantanedicarboxylic acid, norbornenedicarboxylic acid, cyclohexanedicarboxylic acid, decalindicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 1,8-naphthalenedicarboxylic acid, 4,4'-diphenyldicarboxylic acid, 4,4'-diphenyletherdicarboxylic acid, 5-sodiumsulfoisophthalic acid, phenylendanedicarboxylic acid, anthracenedicarboxylic acid, phenanthrenedicarboxylic acid, 9,9'-bis(4-carboxyphenyl)fluorene acid, and ester derivatives thereof.

[0059] Examples of diol compounds include ethylene glycol, 1,2-propanediol, 1,3-propanediol, butanediol, 2-methyl-1,3-propanediol, hexanediol, neopentyl glycol, cyclohexanedimethanol, cyclohexanediethanol, decahydronaphthalenedimethanol, decahydronaphthalenediethanol, norbornanedimethanol, norbornanediethanol, tricyclodecanedimethanol, tricyclodecaneethanol, tetracyclododecanedimethanol, tetracyclododecanediethanol, decalindimethanol, decalindiethanol, 5-methylol-5-ethyl-2-(1,1-dimethyl-2-hydroxyethyl)-1,3-dioxane, cyclohexanediol, bicyclohexyl-4,4'-diol, 2,2-bis(4-hydroxycyclohexylpropane), 2,2-bis(4-(2-hydroxyethoxy)cyclohexyl)propane, cyclopentanediol, 3-methyl-1,2-cyclopentanediol, Examples include pentanediol, 4-cyclopentene-1,3-diol, adamantanediol, paraxylene glycol, bisphenol A, bisphenol S, styrene glycol, trimethylolpropane, and pentaerythritol.

[0060] The polyester may contain a structural unit derived from a polymerizable compound other than a dicarboxylic acid compound and a diol compound. The content of the structural unit may be, for example, 10% by mass or less, 5% by mass or less, or 3% by mass or less.

[0061] The number average molecular weight (Mn) of the polyester may be, for example, 3,000 or more and 30,000 or less, or 6,000 or more and 18,000 or less. In the present disclosure, Mn is measured by gel permeation chromatography (GPC) in accordance with JIS K7252-1 using polystyrene as a standard substance.

[0062] The adhesive layer can contain one or more types of resin materials. The content of the resin material in the adhesive layer is preferably 80% by mass or more, and more preferably 85% by mass or more, relative to the total mass of the adhesive layer.

[0063] The adhesive layer may contain a lubricant, which, for example, can set the dynamic friction coefficient lower, maintain good running properties of the thermal transfer sheet, and suppress wrinkles in the resulting print, for example, when transferring the protective layer for the second time. The details of the lubricant are as described above, and will not be described here.

[0064] The adhesive layer may contain one or more types of lubricants. The content of the lubricant in the adhesive layer may be, for example, 1% by mass to 20% by mass, or 2% by mass to 15% by mass, relative to the total mass of the adhesive layer, which allows, for example, the effect of the lubricant to be exerted while ensuring transparency.

[0065] The adhesive layer may contain one or more of the above additives.

[0066] The thickness of the adhesive layer may be, for example, 0.5 μm or more and 10 μm or less, 0.5 μm or more and 8 μm or less, or 0.5 μm or more and 5 μm or less.

[0067] The adhesive layer can be formed, for example, by applying a coating liquid containing the above-mentioned materials to the release layer by known means such as roll coating, reverse roll coating, gravure coating, reverse gravure coating, bar coating, or rod coating, and then drying the coating.

[0068] <Release layer> In one embodiment, the thermal transfer sheet of the present disclosure includes a release layer located between the substrate and the protective layer. The release layer is an optional layer that allows the protective layer to be easily peeled from the substrate during thermal transfer, and remains on the substrate side during thermal transfer.

[0069] In one embodiment, the release layer contains a binder and a release agent. Examples of binders include resin materials such as (meth)acrylic resin, vinyl resin, polyurethane, polyamide, polyimide, melamine resin, polyol resin, silicone resin, silicone-modified (meth)acrylic resin, fluororesin, fluororesin-modified resin, and cellulose resin. The release layer may contain one or more binders.

[0070] Examples of the release agent include metal soaps such as zinc stearate, zinc stearyl phosphate, calcium stearate, and magnesium stearate, silicone oil, fluorine compounds, phosphate esters, fatty acid amides, polyethylene wax, carnauba wax, and paraffin wax. The release layer may contain one or more types of release agents.

[0071] The release layer may contain one or more of the above additives.

[0072] The thickness of the release layer is preferably 0.5 μm or more and 3 μm or less, more preferably 1 μm or more and 1.5 μm or less, which can improve the transferability of the protective layer in the thermal transfer sheet, for example.

[0073] The release layer can be formed, for example, by applying a coating liquid containing the above-mentioned materials to a substrate by known means such as roll coating, reverse roll coating, gravure coating, reverse gravure coating, bar coating, or rod coating, and then drying the coating.

[0074] <Color layer> The thermal transfer sheet of the present disclosure includes at least one colorant layer on one side of a substrate, in face order with a protective layer. That is, in the thermal transfer sheet of the present disclosure, the colorant layer and the protective layer are provided face-order on one side of the substrate. The colorant layer and the protective layer are provided face-order, for example, in the longitudinal direction of the substrate. By providing the colorant layer and the protective layer on the substrate, for example, it is possible to use the same thermal transfer sheet to form a thermal transfer image on a transfer recipient and to transfer the protective layer onto the formed thermal transfer image.

[0075] In the thermal transfer sheet 1 of the embodiment shown in Figure 1, a single colorant layer 30 is provided on one surface of a substrate 10. Multiple colorant layers, such as a yellow layer, a magenta layer, a cyan layer, and optionally a black layer, may be provided on one surface of the substrate in face-sequential order, for example, in the longitudinal direction of the substrate. In the thermal transfer sheet 1 of the embodiment shown in Figure 7, a yellow layer (Y), a magenta layer (M), a cyan layer (C), and a black layer (BK) are provided in face-sequential order.

[0076] The thermal transfer sheet of the present disclosure may include a repeat of the above-described single unit on one side of the substrate, i.e., multiple units arranged in face order, for example, in the longitudinal direction of the substrate. One unit may include a single colorant layer or multiple colorant layers. When a unit includes multiple colorant layers, i.e., a colorant layer group, the colorant layers are arranged in face order. In one embodiment, one unit includes a yellow layer (Y), a magenta layer (M), a cyan layer (C), a black layer (BK), and a protective layer (OP) (see FIG. 8(a)). In one embodiment, one unit includes a black layer (BK) and a protective layer (OP) (see FIG. 8(b)). Here, the length of the protective layer is at least twice the screen length of each colorant layer (e.g., the yellow layer, magenta layer, cyan layer, and black layer). In the thermal transfer sheet 1 of the embodiment shown in FIG. 8, the length of the protective layer is set to be twice the screen length of each colorant layer.

[0077] The colorant layer may be, for example, a sublimation transfer colorant layer in which a sublimation dye is dissolved or dispersed in a binder, or a melt transfer colorant layer in which a colorant such as a pigment or dye is dispersed in a heat-melt binder. The thermal transfer sheet may include both a sublimation transfer colorant layer and a melt transfer colorant layer. For example, the yellow, magenta, and cyan colorant layers may be sublimation transfer colorant layers, and the black colorant layer may be a melt transfer colorant layer, and these colorant layers may be provided face-sequentially on the substrate. For example, the gradation image portion may be formed by a sublimation transfer recording method, and the character portion may be formed by a melt transfer recording method.

[0078] In one embodiment, the colorant layer contains a binder and a colorant. Examples of binders include resin materials such as polyester, polyurethane, polyamide, polyimide, polycarbonate, polyolefin, (meth)acrylic resin, vinyl resin, styrene resin, cellulose resin, phenoxy resin, and ionomer resin. In addition to the above-mentioned resin materials, waxes such as microcrystalline wax, carnauba wax, paraffin wax, Fischer-Tropsch wax, polyethylene wax, Japan wax, beeswax, whale wax, Ibota wax, wool wax, shellac wax, candelilla wax, petrolactam, polyester wax, partially modified wax, fatty acid ester, and fatty acid amide may also be used as binders in the melt-transfer colorant layer. The melt-transfer colorant layer may contain both a resin material and a wax. The colorant layer may contain one or more types of binder.

[0079] The coloring material may be a pigment such as an organic pigment or an inorganic pigment, or may be a dye. The dye may be a sublimation dye. Specific examples of the coloring material include carbon black, acetylene black, lamp black, black smoke, iron black, aniline black, silica, calcium carbonate, titanium oxide, cadmium red, cadmium phosphate red, chrome red, vermilion, red iron oxide, azo pigments, alizarin lake, quinacridone, cochineal lake perylene, yellow ochre, aureolin, cadmium yellow, cadmium orange, chrome yellow, zinc yellow, Naples yellow, nickel yellow, greenish yellow, ultramarine, rock ultramarine, cobalt, phthalocyanine, anthraquinone, and indicoid. , cinnabar green, cadmium green, chrome green, phthalocyanine, azomethine, perylene, aluminum pigments; and sublimable dyes such as diarylmethane dyes, triarylmethane dyes, thiazole dyes, merocyanine dyes, pyrazolone dyes, methine dyes, indoaniline dyes, acetophenoneazomethine dyes, pyrazoloazomethine dyes, xanthene dyes, oxazine dyes, thiazine dyes, azine dyes, acridine dyes, azo dyes, spiropyran dyes, indolinospiropyran dyes, fluoran dyes, naphthoquinone dyes, anthraquinone dyes, and quinophthalone dyes. Examples of the hues of the coloring materials include magenta, yellow, cyan, and black. The colorant layer can contain one or more types of colorants.

[0080] The colorant layer may contain one or more of the above additives.

[0081] In one embodiment, the colorant layer is a sublimation transfer colorant layer. The content of the binder in the sublimation transfer colorant layer may be, for example, 20% to 95% by mass, or 30% to 90% by mass. The content of the sublimation dye in the sublimation transfer colorant layer may be, for example, 5% to 80% by mass, or 10% to 70% by mass. This can improve, for example, the print density and storage stability.

[0082] The sublimation transfer colorant layer may be cured with a curing agent. Examples of the curing agent include epoxy resin, isocyanate, and carbodiimide. One or more types of curing agents may be used.

[0083] A dye primer layer may be provided between the substrate and the sublimation transfer colorant layer.

[0084] In one embodiment, the colorant layer is a melt transfer type colorant layer. The content of the binder in the melt-transfer colorant layer may be, for example, 20% by mass to 90% by mass, or 30% by mass to 80% by mass, and the content of the colorant in the melt-transfer colorant layer may be, for example, 10% by mass to 60% by mass, or 20% by mass to 50% by mass.

[0085] A release layer may be provided between the substrate and the melt-transfer colorant layer.

[0086] The thickness of the colorant layer is preferably 0.1 μm or more and 20 μm or less, more preferably 0.1 μm or more and 10 μm or less, and even more preferably 0.1 μm or more and 5 μm or less.

[0087] The colorant layer can be formed, for example, by applying a coating liquid containing the above-mentioned materials to a substrate by a known means such as roll coating, reverse roll coating, gravure coating, reverse gravure coating, bar coating, or rod coating, and then drying the applied coating.

[0088] <Back layer> In one embodiment, the thermal transfer sheet of the present disclosure may include a backing layer on the surface of the substrate opposite to the surface on which the protective layer is provided, which can, for example, prevent sticking and wrinkles from occurring during thermal transfer.

[0089] In one embodiment, the back surface layer contains a resin material, such as polyolefin, styrene resin, vinyl resin, polyester, polyurethane, polyether, polyamide, polyimide, polyamideimide, polycarbonate, cellulose resin, or silicone-modified versions of these. The back layer can contain one or more types of resin materials.

[0090] In one embodiment, the back surface layer contains a cured resin obtained by curing a hydroxyl group-containing resin with an isocyanate curing agent, which can, for example, prevent sticking and wrinkles from occurring during thermal transfer.

[0091] Examples of hydroxyl-containing resins include polyvinyl alcohol, polyvinyl butyral, polyvinyl acetal, and (meth)acrylic polyol. The content of hydroxyl-containing structural units in the hydroxyl-containing resin is preferably 5% by mass or more and 30% by mass or less, more preferably 10% by mass or more and 20% by mass or less. This can improve the heat resistance of the back layer, for example, and reduce the thermal energy transmitted to the substrate and protective layer, thereby further improving printability. "Hydroxyl-containing structural units" refers to the proportion of monomer structural units having hydroxyl groups in the resin, and is a value calculated as the proportion (% by mass) of monomer structural units having hydroxyl groups relative to the mass of the entire resin. One or more types of hydroxyl group-containing resins can be used.

[0092] Examples of isocyanate curing agents include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,5-naphthalene diisocyanate, tolidine diisocyanate, p-phenylene diisocyanate, cyclohexane-1,4-diisocyanate, xylylene diisocyanate, triphenylmethane triisocyanate, and tris(isocyanatophenyl)thiophosphate. The isocyanate curing agent may be used alone or in combination of two or more.

[0093] The molar equivalent ratio (-NCO / -OH) of the isocyanate group (-NCO) of the isocyanate curing agent to the hydroxyl group (-OH) of the hydroxyl group-containing resin is preferably 1.5 or more, which can improve the heat resistance of the back layer and reduce the thermal energy transmitted to the substrate and protective layer, thereby further improving printability.

[0094] The content of the cured resin in the back layer is preferably 50% by mass or more and 90% by mass or less, and more preferably 55% by mass or more and 80% by mass or less, which can further improve, for example, the printability.

[0095] The back layer may contain additives such as metal soaps such as zinc stearate, zinc stearyl phosphate, calcium stearate, and magnesium stearate, release agents such as silicone oil, fluorine compounds, phosphate esters, fatty acid amides, polyethylene wax, carnauba wax, and paraffin wax; organic particles such as fluorine resins; inorganic particles such as silica, clay, talc, and calcium carbonate; and organic / inorganic particles such as silicone resins, for the purpose of improving slip properties, etc.

[0096] The content of the additive in the back layer is preferably 10% by mass or more and 50% by mass or less, and more preferably 20% by mass or more and 45% by mass or less, which can further improve slip properties, for example.

[0097] From the viewpoint of improving heat resistance and slip properties, the thickness of the back layer is preferably 0.1 μm or more and 5 μm or less, more preferably 0.3 μm or more and 2 μm or less.

[0098] The back layer can be formed, for example, by applying a coating liquid containing the above-mentioned materials to a substrate by known means such as roll coating, reverse roll coating, gravure coating, reverse gravure coating, bar coating, or rod coating, and then drying the applied coating.

[0099] [Manufacturing method for prints] The method for producing a print according to the present disclosure includes a step of preparing a thermal transfer sheet and a transfer-receiving object (preparation step), an image forming step, a primary transfer step, and a secondary transfer step.

[0100] In the present disclosure, by transferring the protective layer two or more times, two or more protective layers can be laminated on the image. The manufacturing method of the present disclosure can obtain a printed matter having an image composed of characters, line drawings, patterns, symbols, and combinations thereof, and two or more protective layers provided on the image (see Figures 3 and 4).

[0101] <Preparation process> In the preparation step, a thermal transfer sheet and a transfer-receiving material are prepared. The thermal transfer sheet comprises a substrate, at least one colorant layer, and a transferable protective layer. The colorant layer and the protective layer are provided in frame order on one surface of the substrate. The length of the protective layer is at least twice the screen length of the colorant layer. The protective layer has at least a first region and a second region in frame order.

[0102] The thermal transfer sheet used in the method for producing a printed matter of the present disclosure has the same configuration as described above (for example, the layer configuration, the composition and thickness of each layer) as the requirements for the coefficient of dynamic friction, and therefore will not be described here. As the thermal transfer sheet used in the method for producing a printed matter of the present disclosure, it is preferable to use the thermal transfer sheet of the present disclosure described above.

[0103] Examples of the transfer substrate include the resin films, glass substrates, metal substrates, ceramic substrates, cloth substrates, and paper substrates described above as substrates for thermal transfer sheets, as well as laminated substrates thereof. The transfer substrate may also be a card substrate primarily composed of polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, or polycarbonate. Examples of the cloth substrate include substrates formed from fibers such as nylon fibers, polyester fibers, rayon fibers, acetate fibers, acrylic fibers, vinylon fibers, polypropylene fibers, and polyvinylidene chloride fibers; and natural fibers such as cotton, silk, linen, and wool. Examples of the paper substrate include fine paper, plain paper, art paper, coated paper, resin-coated paper, cast-coated paper, cardboard, synthetic paper, and impregnated paper. The transfer substrate may also be, for example, a thermal transfer image-receiving sheet comprising a substrate and a receiving layer provided on one side of the substrate. The transfer substrate may bear an image, may be colored, and may be transparent.

[0104] <Image formation process> In the image forming process, an image is formed on a transferee using the colorant layer of the thermal transfer sheet. For example, the colorant layer of the thermal transfer sheet is brought into contact with the surface of the transferee, and then heat is applied to a desired area of the thermal transfer sheet to form an image on the transferee.

[0105] For example, an image can be formed using a thermal transfer printer having a heating device such as a thermal head. In one embodiment, an image is formed by overlapping a thermal transfer sheet and a transfer recipient, passing them between a thermal head and a platen roll provided in the thermal transfer printer, and heating the thermal transfer sheet using the thermal head. The thermal transfer recording method for forming an image on a transfer recipient may be a sublimation transfer type, a melt transfer type, or a combination of these. For example, a sublimation transfer type and a melt transfer type may be combined, and the gradation image portion may be formed by a sublimation transfer recording method and the character portion may be formed by a melt transfer recording method. Thermal transfer recording can be applied not only to the thermal head method, but also to a thermal transfer means that uses heating by laser irradiation.

[0106] <Primary transfer process> In the primary transfer step, at least a part of the protective layer in the first region of the thermal transfer sheet is transferred so as to cover at least the image formed on the transfer-receiving body.

[0107] For example, the protective layer can be transferred using a thermal transfer printer having a heating device such as a thermal head. In one embodiment, the thermal transfer sheet and the image-formed object are superimposed on each other and passed between a thermal head and a platen roll of the thermal transfer printer, and the thermal transfer sheet is heated using the thermal head, thereby transferring the protective layer so as to cover the image formed on the image-formed object. The protective layer may be transferred using a heat roll method. The protective layer may be transferred by sandwiching the thermal transfer sheet and the image-formed object between heated flat plates, or between heated flat plates and rolls, and then hot pressing.

[0108] When a thermal head is used as a thermal transfer means for the protective layer, the same thermal head as that used for image formation may be used, or a different thermal head may be used. In the present disclosure, it is preferable that the thermal transfer means for image formation and the thermal transfer means for the protective layer are performed in-line using a single thermal transfer printer, and when two or more protective layers are superimposed on an image formed on a transfer recipient, it is also preferable that the lamination of the protective layers is performed in-line.

[0109] <Secondary transfer process> In the secondary transfer step, at least a portion of the protective layer in the second region of the thermal transfer sheet is transferred onto the protective layer transferred onto the image. For example, the protective layer can be transferred using a thermal transfer printer having a heating device such as a thermal head. The same thermal transfer means as used in the primary transfer step can be used as the thermal transfer means for the protective layer in the secondary transfer step.

[0110] The method for producing a print according to the present disclosure is characterized in that the coefficient of dynamic friction between the surface of the protective layer transferred onto the image in the primary transfer step and the surface of the protective layer in the second region of the thermal transfer sheet is 0.34 or more and 0.85 or less. The coefficient of dynamic friction is preferably 0.34 or more and 0.60 or less. This can prevent wrinkles from occurring in the resulting print, for example, when the protective layer is thermally transferred onto the transfer target object two or more times.

[0111] For example, by using the thermal transfer sheet of the present disclosure as the thermal transfer sheet, the dynamic friction coefficient can be achieved in the above range. Alternatively, the dynamic friction coefficient can be reduced by transferring the protective layer under conditions of high transfer energy in the primary transfer step to form minute irregularities on the surface of the protective layer transferred onto the transfer recipient.

[0112] The present disclosure relates to, for example, the following [1] to [9]. [1] A thermal transfer sheet comprising a substrate, at least one colorant layer, and a transferable protective layer, wherein the colorant layer and the protective layer are provided in face-sequential order on one side of the substrate, the length of the protective layer is at least twice the screen length of the colorant layer, and the coefficient of dynamic friction between the surface of the protective layer opposite the substrate and the surface of the protective layer facing the substrate is 0.34 or more and 0.85 or less. [2] The thermal transfer sheet according to [1] above, wherein the transferable protective layer comprises a release layer and an adhesive layer from the substrate side. [3] The thermal transfer sheet according to [2] above, wherein the release layer contains a (meth)acrylic resin. [4] The thermal transfer sheet according to [2] or [3] above, wherein the release layer contains a lubricant. [5] The thermal transfer sheet according to any one of the above [2] to [4], wherein the adhesive layer contains at least one selected from vinyl chloride-vinyl acetate copolymer and polyester. [6] The thermal transfer sheet according to any one of the above [2] to [5], wherein the adhesive layer contains a lubricant. [7] A thermal transfer sheet according to any one of the above [1] to [6], wherein the colorant layer has at least a yellow layer, a magenta layer, and a cyan layer, the yellow layer, the magenta layer, the cyan layer, and the protective layer are provided in frame order, and the length of the protective layer is at least twice the screen length of each of the yellow layer, the magenta layer, and the cyan layer. [8] A thermal transfer sheet according to any one of the above [1] to [6], wherein the colorant layer has at least a black layer, the black layer and the protective layer are provided in frame order, and the length of the protective layer is at least twice the screen length of the black layer. [9] A method for producing a print including a step of preparing a thermal transfer sheet and a transferee, an image forming step, a primary transfer step, and a secondary transfer step, wherein the thermal transfer sheet comprises a substrate, at least one colorant layer, and a transferable protective layer, the colorant layer and the protective layer are provided in surface order on one surface of the substrate, the length of the protective layer is at least twice the screen length of the colorant layer, and the protective layer has at least a first region and a second region in surface order, and the image forming step forms an image on the transferee by the colorant layer provided in the thermal transfer sheet. a primary transfer step of transferring at least a portion of a protective layer of a first region of the thermal transfer sheet so as to at least cover an image formed on a transfer recipient; a secondary transfer step of transferring at least a portion of a protective layer of a second region of the thermal transfer sheet onto the protective layer transferred onto the image; and a kinetic friction coefficient between the surface of the protective layer transferred onto the image in the primary transfer step and the surface of the protective layer of the second region of the thermal transfer sheet is 0.34 or more and 0.85 or less. [Example]

[0113] The thermal transfer sheet of the present disclosure will be described below based on examples, but the thermal transfer sheet of the present disclosure is not limited to these examples. In the following description, "parts by mass" will be simply referred to as "parts." The amounts of components contained in the coating liquid described below are solid content amounts.

[0114] [Example 1] A PET film (Lumirror (registered trademark) #5A-F53, Toray Industries, Inc.) with a thickness of 5 μm or less was prepared as a substrate. The following back layer coating liquid was applied to one side of the PET film and dried at 100°C for 2 minutes to form a 1.2 μm thick back layer. The following yellow dye layer coating liquid, the following magenta dye layer coating liquid, and the following cyan dye layer coating liquid were applied in face order to the side of the PET film opposite the back layer and dried at 80°C for 1 minute to form a 1 μm thick yellow dye layer, a 1 μm thick magenta dye layer, and a 1 μm thick cyan dye layer in face order on the PET film. Furthermore, the following release layer coating liquid was applied to the PET film in face order to these dye layers and dried at 100°C for 1 minute to form a 1 μm thick release layer. The adhesive layer coating solution described below was applied to the release layer and dried at 100°C for 1 minute to form an adhesive layer with a thickness of 1.5 μm. The protective layer was composed of a release layer and an adhesive layer. The length of the protective layer in the longitudinal direction of the PET film was designed to be twice the screen length of each dye layer. In this manner, a thermal transfer sheet was obtained.

[0115] <Coating liquid for back layer> Polyvinyl acetal 36 parts (S-LEC (registered trademark) KS-1, Sekisui Chemical Co., Ltd.) Polyisocyanate (NCO=17.3% by mass) 25 parts (Burnoc® D750, DIC Corporation) Silicone resin fine particles (average particle diameter = 4 μm, polygonal shape) 1 part (Tospearl 240, Momentive Performance Materials Japan LLC Zinc stearyl phosphate 10 parts (LBT1830 refined, Sakai Chemical Industry Co., Ltd.) Zinc stearate 10 parts (SZ-PF, Sakai Chemical Industry Co., Ltd.) 3 parts polyethylene wax (Polywax 3000, Toyo ADL Co., Ltd.) Ethoxylated alcohol-modified wax 7 parts (Unitox 750, Toyo ADL Co., Ltd.) 200 parts methyl ethyl ketone (MEK) 100 parts toluene

[0116] <Coating liquid for yellow dye layer> 6 parts Solvent Yellow 93 Polyvinyl acetal 5 parts (Manufactured by Sekisui Chemical Co., Ltd., product name: S-LEC (registered trademark) KS-5) ·MEK 50 copies 50 parts toluene

[0117] <Coating liquid for magenta dye layer> 3 parts Disperse Red 60 4 parts Disperse Violet 26 Polyvinyl acetal 5 parts (Manufactured by Sekisui Chemical Co., Ltd., product name: S-LEC (registered trademark) KS-5) ·MEK 50 copies 50 parts toluene

[0118] <Coating liquid for cyan dye layer> 4 parts Solvent Blue 63 Disperse Blue 354 4 parts Polyvinyl acetal 5 parts (Manufactured by Sekisui Chemical Co., Ltd., product name: S-LEC (registered trademark) KS-5) ·MEK 50 copies 50 parts toluene

[0119] <Coating liquid for release layer> (Meth)acrylic resin A 20 parts (0403KA, Taisei Fine Chemical Co., Ltd., Tg: 105°C, Mw: 73,000 ·MEK 40 copies 40 parts toluene

[0120] <Coating liquid for adhesive layer> Vinyl chloride-vinyl acetate copolymer 20 parts (VINNOL® H14 / 36, Wacker Chemie AG, Vinyl chloride content: 86% by mass, vinyl acetate content: 14% by mass, Tg: 69°C, Mw: 30,000-40,000) ·MEK 40 copies 40 parts toluene

[0121] [Examples 2 to 12 and Comparative Examples 1 to 5] A thermal transfer sheet was obtained in the same manner as in Example 1, except that the solid components in the release layer and / or adhesive layer were changed to the components shown in Table 1.

[0122] The components used in the examples and comparative examples are listed below. (Meth)acrylic resin B: KV-4941, Shin-Nakamura Chemical Co., Ltd. Tg: 61°C, Mw: 33,000 Saturated copolymer polyester: UE-3380, Unitika Ltd. Tg: 60℃ Polyethylene wax: POLYWAX® 655, Baker Hughes, melting point: 99°C Silica particles: NIPGEL (registered trademark) AZ-400, Tosoh Silica Corporation, Average secondary particle size: 3.0μm Silicone oil: KF-96, Shin-Etsu Chemical Co., Ltd.

[0123] [How to evaluate wrinkles in prints] A first protective layer transfer was performed on a PVC card (standard white card, manufactured by Dai Nippon Printing Co., Ltd.) using the thermal transfer sheets obtained in the Examples and Comparative Examples and a card printer SD360 (Enrast) at an energy setting of ±0. A second protective layer transfer was performed on the protective layer of the PVC card to which the protective layer had been transferred using a card printer SD360 (Enrast) at an energy setting of +10 or +20. The presence or absence of wrinkles in the print was confirmed by visual inspection. · AA: Visual inspection shows that there are no wrinkles on the printed image on the PVC card after the protective layer has been transferred. BB: Visual inspection reveals wrinkles in the printed image on the PVC card after the protective layer has been transferred.

[0124] [Dynamic friction coefficient] In accordance with JIS K7125:1999 "Plastics - Films and Sheets - Test Method for Coefficient of Friction," the dynamic friction coefficient was measured between the surface of the protective layer of the thermal transfer sheet (second surface of the protective layer) and the surface of the protective layer of the print obtained by transferring the protective layer to a PVC card the first time (first surface of the protective layer). The dynamic friction coefficient was measured under the following conditions: load of sliding piece: 1.96 N, contact area of sliding piece: 22 cm 2 The test speed was 1000 mm / min.

[0125] [Table 1] [Explanation of symbols]

[0126] 1...Thermal transfer sheet 2. Prints 10...Base material 20...Transferable protective layer 20a...first region of protective layer 20b...Second region of protective layer 22...Release layer 24...Adhesive layer 26...First surface of transferable protective layer 28...Second surface of transferable protective layer 30...color material layer 40...Back layer 50...Transferred object

Claims

1. A thermal transfer sheet comprising a substrate, at least one colorant layer, and a transferable protective layer, the color material layer and the protective layer are provided in face order on one surface of the base material, The length of the protective layer is at least twice the screen length of the color material layer, the protective layer has at least a first region and a second region arranged in frame sequence, At least a portion of the protective layer in the first region is transferred from the thermal transfer sheet onto a transfer-receiving object, a dynamic friction coefficient between a surface of the protective layer opposite to the substrate and a surface of the protective layer transferred onto the transfer-receiving body is 0.34 or more and 0.85 or less; Thermal transfer sheet.

2. The thermal transfer sheet according to claim 1 , wherein the transferable protective layer comprises a release layer and an adhesive layer from the substrate side.

3. The thermal transfer sheet according to claim 2 , wherein the release layer contains a (meth)acrylic resin.

4. The thermal transfer sheet according to claim 2 or 3, wherein the release layer contains a lubricant.

5. 5. The thermal transfer sheet according to claim 2, wherein the adhesive layer contains at least one selected from vinyl chloride-vinyl acetate copolymers and polyesters.

6. The thermal transfer sheet according to any one of claims 2 to 5, wherein the adhesive layer contains a lubricant.

7. 7. The thermal transfer sheet according to claim 1, wherein the colorant layer has at least a yellow layer, a magenta layer, and a cyan layer, the yellow layer, the magenta layer, the cyan layer, and the protective layer are provided in face order, and the length of the protective layer is at least twice the screen length of each of the yellow layer, the magenta layer, and the cyan layer.

8. The thermal transfer sheet according to any one of claims 1 to 6, wherein the color material layer has at least a black layer, the black layer and the protective layer are provided in frame sequence, and the length of the protective layer is at least twice the screen length of the black layer.

9. A step of preparing a thermal transfer sheet and a transfer receiving material; an image forming process; a primary transfer step; Secondary transfer process A method for producing a print comprising: the thermal transfer sheet comprises a substrate, at least one color material layer, and a transferable protective layer, the color material layer and the protective layer being provided in frame order on one surface of the substrate, the length of the protective layer being at least twice the screen length of the color material layer, and the protective layer having at least a first region and a second region in frame order; the image forming step is a step of forming an image on the transfer-receiving body using the color material layer provided in the thermal transfer sheet, the primary transfer step is a step of transferring at least a part of a protective layer of a first region of the thermal transfer sheet so as to cover at least the image formed on the transfer-receiving body; the secondary transfer step is a step of transferring at least a part of the protective layer of the second region of the thermal transfer sheet onto the protective layer transferred onto the image, and the dynamic friction coefficient between the surface of the protective layer transferred onto the image in the primary transfer step and the surface of the protective layer of the second region of the thermal transfer sheet is 0.34 or more and 0.85 or less; Method for producing printed matter.

Images