Thermal transfer sheet and method for manufacturing printed matter

Abstract

To improve thin line printing properties in a thermal transfer sheet and preventing an occurrence of tailing.SOLUTION: A thermal transfer sheet includes a base material and a first transfer layer disposed on the base material. The thermal transfer sheet further includes a release layer between the base material and the first transfer layer. The release layer contains olefinic polymer, vinyl alcohol-based polymer and vinyl chloride-vinyl acetate copolymer.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] Conventionally, a thermal melt transfer method is known as a method for forming an image on a transferee. In this method, a thermal head is used to apply energy to a thermal transfer sheet having a substrate and a melt transfer type color material layer, and the melt transfer type color material layer is transferred onto the transferee to form an image. Images formed by the thermal melt transfer method have high density and excellent sharpness, so this method is suitable for forming binary images such as characters and line drawings.

[0003] It is also common to manufacture prints by combining a thermal transfer sheet having a melt-transfer type color material layer with an intermediate transfer medium having a transfer layer (see, for example, Patent Document 1). First, the thermal transfer sheet and the intermediate transfer medium are superimposed, and then the thermal transfer sheet is heated by a thermal head of the thermal transfer printer, thereby transferring the melt-transfer type color material layer onto the transfer layer of the intermediate transfer medium (primary transfer) and forming an image. Next, the intermediate transfer medium and a transfer recipient are superimposed, and the intermediate transfer medium is heated, thereby transferring the transfer layer on which the image has been formed onto the transfer recipient (secondary transfer). In this manner, a print is manufactured. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2018-187832 A Summary of the Invention [Problem to be solved by the invention]

[0005] When forming an image on the transfer layer of an intermediate transfer medium or a transferee using a thermal transfer sheet, fine line printability is required to form a fine line image without causing blurring or crushing. In addition, it is desirable to be able to suppress the occurrence of tailing during the above image formation. The tailing refers to a phenomenon in which, when a transfer layer (first transfer layer) such as a melt transfer type color material layer in a thermal transfer sheet is transferred onto a transfer layer (second transfer layer) of an intermediate transfer medium or a transferee, the transfer layer is transferred so as to protrude from the boundary between the transfer area and the non-transfer area of ​​the first transfer layer as a starting point, into the non-transfer area side. In order to improve these physical properties, it has been considered to provide a release layer between the substrate and the first transfer layer in the thermal transfer sheet. However, the improvement in the above physical properties has not been sufficient.

[0006] An object of the present disclosure is to improve the fine line printability of a thermal transfer sheet and suppress the occurrence of tailing, and to provide a method for producing a printed matter using such a thermal transfer sheet and an intermediate transfer medium. [Means for solving the problem]

[0007] The thermal transfer sheet of the present disclosure includes a substrate and a first transfer layer provided on the substrate. The thermal transfer sheet may include a release layer between the substrate and the first transfer layer. The release layer may include an olefin polymer, a vinyl alcohol polymer, and a vinyl chloride-vinyl acetate copolymer. The method for producing a printed matter of the present disclosure includes the steps of preparing the above-mentioned thermal transfer sheet, and an intermediate transfer medium comprising a support and a second transfer layer provided on the support, transferring the first transfer layer of the thermal transfer sheet onto the second transfer layer of the intermediate transfer medium, and transferring the second transfer layer to which the first transfer layer has been transferred from the intermediate transfer medium onto a recipient. Effect of the Invention

[0008] According to the present disclosure, it is possible to improve the fine line printability of the thermal transfer sheet and suppress the occurrence of tailing. According to the present disclosure, it is possible to provide a method for producing a printed matter using such a thermal transfer sheet and an intermediate transfer medium. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic cross-sectional view showing one embodiment of the thermal transfer sheet of the present disclosure. [Diagram 2] FIG. 2 is a schematic cross-sectional view showing one embodiment of the thermal transfer sheet of the present disclosure. [Diagram 3] FIG. 3 is a schematic cross-sectional view showing one embodiment of the thermal transfer sheet of the present disclosure. [Figure 4] FIG. 4 is a schematic cross-sectional view showing one embodiment of the thermal transfer sheet of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, the embodiments of the present disclosure will be described in detail. The present disclosure can be implemented in many different forms, and is not to be interpreted as being limited to the description of the embodiments exemplified below. In the drawings, the width, thickness, shape, etc. of each layer may be shown diagrammatically in order to make the explanation clearer, but these are merely examples and do not limit the interpretation of the present disclosure. In this specification and each figure, elements similar to those already explained with respect to the previous figures are given the same reference numerals, and detailed explanations may be omitted as appropriate.

[0011] [Thermal transfer sheet] The thermal transfer sheet of the present disclosure comprises a substrate and a first transfer layer provided on the substrate. The thermal transfer sheet includes a release layer between the substrate and the first transfer layer.

[0012] Fig. 1 is a schematic cross-sectional view showing one embodiment of the thermal transfer sheet of the present disclosure. The thermal transfer sheet 1 in Fig. 1 includes a substrate 10 and a first transfer layer 20 provided on the substrate 10, and includes a release layer 30 between the substrate 10 and the first transfer layer 20. In this embodiment, the first transfer layer 20 is made of a first color material layer 22.

[0013] 2 is a schematic cross-sectional view showing one embodiment of the thermal transfer sheet of the present disclosure. In Fig. 2, the first transfer layer 20 includes a release layer 24 and a first color material layer 22 in this order from the substrate 10 side in the thickness direction of the thermal transfer sheet 1.

[0014] 1 and 2 includes a back layer 40 on the surface of the substrate 10 opposite to the first transfer layer 20. The thermal transfer sheet 1 of the embodiment in Figs. 1 and 2 may include a primer layer (not shown) between the substrate 10 and the release layer 30.

[0015] By using the thermal transfer sheet of the present disclosure, it is possible to form a thermal transfer image that has excellent fine line printability and suppresses the occurrence of tailing, as described below. In this specification, the thermal transfer image is composed of, for example, characters, line drawings, patterns, symbols, and combinations thereof. Hereinafter, each layer of the thermal transfer sheet of the present disclosure will be described.

[0016] <Base material> There are no particular limitations on the substrate, so long as it has heat resistance to the thermal energy applied during thermal transfer and has the mechanical strength to support the first transfer layer and the like provided on one surface of the substrate.

[0017] The substrate may be, for example, a film made of a resin material (hereinafter also referred to as a "resin film"). Examples of the resin material include polyesters such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, 1,4-polycyclohexylene dimethylene terephthalate, and terephthalic acid-cyclohexane dimethanol-ethylene glycol copolymers; polyamides; polyimides; polycarbonates; polyolefins such as polyethylene, polypropylene, and polymethylpentene; polystyrenes; vinyl resins such as vinyl chloride resins, vinyl acetate resins, vinyl chloride-vinyl acetate copolymers, polyvinyl alcohol, and polyvinyl pyrrolidone; vinyl acetal resins such as polyvinyl acetoacetal and polyvinyl butyral; (meth)acrylic resins such as poly(meth)acrylate; cellulose resins such as cellophane, cellulose acetate, nitrocellulose, cellulose acetate propionate, and cellulose acetate butyrate; and ionomers.

[0018] Among the above resin materials, from the viewpoints of heat resistance and mechanical strength, polyester is preferred, polyethylene terephthalate (PET) and polyethylene naphthalate (PEN) are more preferred, and PET is even more preferred.

[0019] In the present disclosure, "(meth)acrylic" includes both "acrylic" and "methacrylic", and "(meth)acrylate" includes both "acrylate" and "methacrylate".

[0020] A laminate of resin films may be used as the substrate. The laminate of resin films can be produced by, for example, a dry lamination method, a wet lamination method, or an extrusion method.

[0021] The resin film may be a stretched film or an unstretched film. From the viewpoint of strength, a stretched film that is uniaxially or biaxially stretched is preferred.

[0022] The thickness of the substrate is preferably from 1.0 μm to 50.0 μm, more preferably from 3.0 μm to 25.0 μm, which can improve, for example, the mechanical strength of the substrate and the transfer of thermal energy during thermal transfer.

[0023] <First transfer layer> The first transfer layer is a layer that can be peeled off from the substrate by thermal transfer. In one embodiment, the first transfer layer includes a first colorant layer. In one embodiment, the first transfer layer further includes a release layer. The release layer constitutes a surface layer of the first transfer layer on the substrate side.

[0024] (First color material layer) In one embodiment, the first transfer layer includes a first colorant layer. By using such a thermal transfer sheet, for example, a thermal transfer image can be formed on the second transfer layer of the intermediate transfer medium or on a transfer receiving body.

[0025] The first color material layer is used, for example, to form an image. The first color material layer contains a color material. The color material may be a pigment or a dye. The first color material layer is a melt transfer type color material layer to which the color material layer itself is transferred.

[0026] In one embodiment, the first colorant layer contains a colorant and a binder. The coloring material preferably has sufficient coloring density and does not discolor or fade due to light, heat, etc. Examples of the coloring material include organic pigments, inorganic pigments, and dyes. Examples of the coloring material include cyan, magenta, yellow, and black, as well as various other colors. The first coloring material layer can contain one or more types of coloring materials.

[0027] Specific examples of coloring materials include inorganic pigments such as carbon black, calcium carbonate, titanium oxide, zinc oxide, silica, iron oxide, yellow iron oxide, ultramarine blue, aluminum pigments, metallic pigments, and pearl pigments, as well as organic pigments and dyes.

[0028] The content of the color material in the first color material layer is preferably 10% by mass to 85% by mass, more preferably 15% by mass to 70% by mass, which can improve, for example, the image density of the thermal transfer image to be formed.

[0029] Examples of the binder include a resin material and a wax. Examples of the resin material include (meth)acrylic resin, ethylene-vinyl acetate copolymer, ethylene-(meth)acrylic acid ester copolymer, vinyl chloride resin, vinyl acetate resin, vinyl chloride-vinyl acetate copolymer, vinylidene chloride resin, polyolefins such as polyethylene, polypropylene, polybutene, and polyisobutylene, polystyrene, polyester, polyamide, polycarbonate, polyvinyl alcohol, polyvinyl formal, polyvinyl butyral, cellulose resins such as acetyl cellulose, nitrocellulose, and ethyl cellulose, petroleum resin, fluororesin, epoxy resin, and ionomer resin.

[0030] Examples of waxes include microcrystalline wax, carnauba wax, paraffin wax, Fischer-Tropsch wax, various low molecular weight polyethylenes, wood wax, beeswax, whale wax, ivory wax, wool wax, shellac wax, candelilla wax, petrolactam, polyester wax, partially modified waxes, fatty acid esters, and fatty acid amides.

[0031] The binder is preferably a resin material, more preferably a (meth)acrylic resin, a vinyl chloride-vinyl acetate copolymer, or a polyester, and further preferably a vinyl chloride-vinyl acetate copolymer or a polyester.

[0032] The first color material layer may contain one or more types of binders. The content of the binder in the first color material layer is preferably 15% by mass to 90% by mass, more preferably 30% by mass to 85% by mass.

[0033] The first color material layer may contain one or more additives, such as metal soaps, plasticizers, antistatic agents, UV absorbers, inorganic particles, organic particles, release agents, and dispersants.

[0034] The thickness of the first color material layer is preferably 0.1 μm to 10.0 μm, more preferably 0.3 μm to 8.0 μm, and even more preferably 0.5 μm to 5.0 μm, which can, for example, further improve the printability of the thermal transfer sheet and the solvent resistance of the formed thermal transfer image.

[0035] In one embodiment, the first color material layer constitutes a surface layer of the first transfer layer on the side opposite to the substrate. In this embodiment, when the first transfer layer is transferred onto, for example, a second transfer layer of an intermediate transfer medium or a transferee using a thermal transfer sheet, the first color material layer comes into contact with the second transfer layer or the transferee.

[0036] In one embodiment, the first color material layer contains a metallic pigment and a binder. Hereinafter, such a color material layer is also referred to as a "metallic pigment-containing layer." Metal-based pigments include, for example, metal pigments, metal oxide pigments, and coated pigments. Examples of metal pigments include particles composed of metals such as aluminum, iron, titanium, zirconium, silicon, cerium, nickel, chromium, brass, tin, brass, bronze, zinc, silver, platinum, gold, and indium. Examples of metal oxide pigments include particles composed of oxides of the metals.

[0037] Among the metal pigments, aluminum particles are preferred, and scaly aluminum pigments, i.e., aluminum flakes, are more preferred. The aluminum pigment may be of either a leafing type or a non-leafing type.

[0038] The hiding power of the metallic pigment may be 2.0 or more, or 2.5 or more. In one embodiment, this can suppress the influence on the color of the image formed on the printed matter. The hiding power of the metallic pigment may be 6.0 or less, or 5.5 or less. In the present disclosure, the hiding power of the metallic pigment is measured in accordance with JIS K5600-4-1.

[0039] The coated pigment comprises a core material and a coating material, such as a metal or metal oxide, that coats the core material. The material constituting the core material of the coated pigment may be an inorganic material or an organic material. Examples of inorganic materials include natural mica, synthetic mica, glass, aluminum, and alumina. Examples of organic materials include resin materials such as polyester, polyamide, polyolefin, vinyl resin, and (meth)acrylic resin.

[0040] Examples of the coating material include metals such as aluminum, iron, titanium, zirconium, silicon, cerium, nickel, chromium, brass, tin, brass, bronze, zinc, silver, platinum, gold, and indium, as well as oxides of the metals. Examples of the oxides of the metals include titanium oxide and iron oxide. The coating material that covers the core material can be formed, for example, by vapor deposition.

[0041] In one embodiment, the coating material is preferably a metal from the viewpoint of improving the brilliance of the printed matter. The coating material preferably contains gold or silver, and more preferably is composed of gold or silver. This can further improve the brilliance of the printed matter, for example.

[0042] In one embodiment, the core material preferably contains glass, and more preferably is made of glass. In one embodiment, the coating material is preferably a metal. The coating material preferably contains gold or silver, and more preferably is made of gold or silver. In one embodiment, the coated pigment is a particle in which glass is coated with a metal, specifically, a particle in which glass is coated with gold or silver. This, for example, has little effect on the color of the coating material, and can further improve the brilliance of the printed matter.

[0043] In one embodiment, the core material preferably contains mica, and more preferably is made of mica. In one embodiment, the coating material is preferably a metal oxide. The coating material preferably contains titanium oxide or iron oxide, and more preferably is made of titanium oxide or iron oxide. In one embodiment, the coated pigment is a particle in which mica is coated with a metal oxide, specifically, a particle in which mica is coated with titanium oxide or iron oxide. This can further improve the gloss of the printed matter, for example.

[0044] The shape of the metallic pigment is, for example, spherical, needle-like, or scaly.

[0045] The average particle size of the metallic pigment is preferably 1 μm or more and 100 μm or less, more preferably 3 μm or more and 40 μm or less. This can improve the design of the printed matter, for example. In the present disclosure, the average particle size of the metallic pigment means the volume average particle size, and is measured in accordance with JIS Z8819-2:2019.

[0046] In the present disclosure, a thermal transfer sheet having a specific release layer described later and a metal-based pigment-containing layer as a first color material layer is preferred. Conventionally, it has been difficult for a color material layer containing a metal-based pigment having a larger particle size than a color material such as carbon black to simultaneously improve fine line printability and suppress the occurrence of tailing. The specific release layer in the present disclosure shows an excellent effect of improving fine line printability and suppressing the occurrence of tailing even in combination with a color material layer containing a metal-based pigment.

[0047] In one embodiment, the average particle size of the metal pigment or metal oxide pigment is preferably 4 μm or more and 10 μm or less, more preferably 4.5 μm or more and 9.5 μm or less, which can improve the design of the printed matter, for example.

[0048] In one embodiment, the average particle size of the coated pigment is preferably 3 μm or more and 100 μm or less, more preferably 5 μm or more and 40 μm or less, which can improve the design of the printed matter, for example.

[0049] When the metallic pigment is a scaly particle, the particle thickness of the metallic pigment may be 0.5 μm or more and 10 μm or less. This can, for example, improve the design of the printed matter and improve the transferability of the thermal transfer sheet. The particle thickness of the metallic pigment can be measured by extracting a predetermined number (preferably 100 or more) of scaly particles from the particle group to be measured and measuring their thickness using an electron microscope.

[0050] The metallic pigment-containing layer can contain one or more types of metallic pigments. The content of the metallic pigment in the metallic pigment-containing layer is preferably from 23% to 83% by mass, more preferably from 33% to 67% by mass, which can improve the design of the printed matter, for example.

[0051] Examples of the binder include the above-mentioned resin materials and wax. The binder is preferably a resin material, more preferably a (meth)acrylic resin, a vinyl chloride-vinyl acetate copolymer, or a polyester, and further preferably a vinyl chloride-vinyl acetate copolymer or a polyester.

[0052] The metallic pigment-containing layer can contain one or more types of binder. The content of the binder in the metal-based pigment-containing layer is preferably 17% by mass to 77% by mass, more preferably 33% by mass to 67% by mass, which can, for example, improve the transferability of the first transfer layer and the adhesion between the first transfer layer and the second transfer layer of the intermediate transfer medium.

[0053] The ratio of the metallic pigment content to the binder content in the metallic pigment-containing layer (PV ratio=metallic pigment content / binder content) is preferably 0.3 to 5.0, more preferably 0.3 to 1.8, and even more preferably 0.4 to 1.5, by mass. This can further improve, for example, the transferability of the first transfer layer and the adhesion between the first transfer layer and the second transfer layer of the intermediate transfer medium.

[0054] The metallic pigment-containing layer may contain one or more of the above additives.

[0055] The first color material layer can be formed, for example, by dispersing or dissolving each of the above components in water or a suitable organic solvent to prepare a coating liquid, and applying the coating liquid to an object on which the first color material layer is to be formed by a known means, and drying the coating liquid. Examples of the means include roll coating, reverse roll coating, gravure coating, reverse gravure coating, bar coating, and rod coating. Each layer described below can also be formed by the same method.

[0056] (Release layer) In one embodiment, the first transfer layer in the thermal transfer sheet includes a release layer as the layer that is located closest to the substrate among the layers that constitute the first transfer layer. The release layer is a layer that is transferred together with the first color material layer during thermal transfer. By providing the release layer, the transferability of the first transfer layer can be further improved. The release layer is transferred as a part of the first transfer layer during thermal transfer, and becomes the surface layer of the thermal transfer image after transfer, and acts to improve the scratch resistance of the thermal transfer image.

[0057] The components contained in the release layer include, for example, a resin material and a wax. Examples of the resin material include vinyl resins such as (meth)acrylic resin, vinyl chloride resin, vinyl acetate resin, and vinyl chloride-vinyl acetate copolymer, cellulose resin, polyester, polyurethane, silicone resin, and fluororesin, as well as various resins modified with silicone or fluorine. The release layer can contain one or more types of resin materials.

[0058] Examples of waxes include natural waxes such as beeswax, spermaceti, Japan wax, rice bran wax, carnauba wax, candelilla wax, and montan wax; synthetic waxes such as paraffin wax, microcrystalline wax, silicone wax, oxidized wax, ozokerite, ceresin, ester wax, and polyethylene 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 fatty acid esters of sorbitan; and higher fatty acid amides such as stearic acid amide and oleic acid amide. The release layer can contain one or more types of wax.

[0059] The above resin materials and waxes are preferred from the viewpoint of imparting good releasability to the release layer. Among these, resin materials are preferred, and (meth)acrylic resins and vinyl resins are more preferred, from the viewpoint of further improving the coatability of the release layer coating liquid and the abrasion resistance of the thermal transfer image formed. The release layer may contain wax together with the resin material.

[0060] The total content of the resin material and the wax in the release layer is preferably 70% by mass or more and 100% by mass or less, and more preferably 80% by mass or more and 100% by mass or less.

[0061] The release layer may contain one or more of the above additives.

[0062] The thickness of the release layer is preferably 0.1 μm or more and 3.0 μm or less, and more preferably 0.2 μm or more and 2.0 μm or less, which can, for example, further improve the transferability of the first transfer layer.

[0063] <Release layer> The thermal transfer sheet of the present disclosure includes a release layer between the substrate and the first transfer layer. The release layer is a layer that improves the peelability of the first transfer layer provided on the substrate. The release layer is a layer that does not constitute the first transfer layer, and is a layer that remains on the substrate side when the first transfer layer is transferred, for example, to the second transfer layer of an intermediate transfer medium or onto a transferee. When the thermal transfer sheet includes a melt-transfer type color material layer as the second color material layer described later, the thermal transfer sheet may further include the release layer between the substrate and the melt-transfer type color material layer.

[0064] The release layer contains an olefin polymer, a vinyl alcohol polymer, and a vinyl chloride-vinyl acetate copolymer. The release layer contains at least the above three components, so that the releasability of the first transfer layer from the release layer becomes appropriate, and for example, the primary transferability and secondary transferability can be improved, and the adhesion between the substrate and the release layer can be improved. Specifically, when the first transfer layer is peeled off from the release layer, the peeling force is appropriate, so that a fine line image can be formed without causing blurring or crushing, the occurrence of tailing can be suppressed, and the so-called foil drop, in which the first transfer layer peels off from the substrate when not heated, can be suppressed. Hereinafter, the fine line printability and tailing suppression are collectively referred to simply as "printing performance".

[0065] The olefin polymer may be, for example, an unmodified olefin polymer or a modified olefin polymer (hereinafter also referred to as a "modified olefin polymer").

[0066] Examples of unmodified olefin polymers include homopolymers of α-olefins, copolymers of two or more kinds of α-olefins, and copolymers of α-olefins and other non-polar monomers. Examples of the form of the copolymer include random copolymers and block copolymers.

[0067] Examples of α-olefins include ethylene, propylene, 1-butene, 4-methyl-1-pentene, 3-methyl-1-butene, 1-hexene, 1-octene, and 1-decene. The number of carbon atoms in the α-olefin is preferably 2 to 20, more preferably 2 to 10. The α-olefins are preferably ethylene and propylene, and more preferably ethylene. One or more types of α-olefins can be used.

[0068] Examples of non-polar monomers other than α-olefins include styrene-based monomers such as styrene, conjugated dienes such as butadiene, and cyclic olefins such as norbornene. The copolymer may have a structural unit derived from a non-polar monomer other than α-olefin in a range of, for example, 30% by mass or less, 20% by mass or less, or 10% by mass or less. In the present disclosure, the content of each structural unit is measured by nuclear magnetic resonance (NMR) method. One or more types of non-polar monomers can be used.

[0069] Specific examples of unmodified olefin polymers include polyethylene, polypropylene, polybutene, and poly(4-methyl-1-pentene). In the present disclosure, polyethylene is not limited to a homopolymer of ethylene, but also includes, for example, copolymers of ethylene and other monomers. The same applies to polypropylene and the like.

[0070] The modified olefin polymer may be, for example, an acid-modified product of an olefin polymer (hereinafter also referred to as "acid-modified olefin polymer"). The acid-modified olefin polymer may be, for example, a copolymer of the above-mentioned α-olefin, optionally the above-mentioned non-polar monomer, and an acid component. The acid component may be randomly copolymerized, block-copolymerized, or graft-copolymerized (graft-modified). That is, in the acid-modified olefin polymer, the structural unit derived from the acid component may be contained in the polymer main chain in the form of random copolymerization or block copolymerization, or may be contained in the polymer side chain in the form of graft modification.

[0071] The acid component includes, for example, unsaturated carboxylic acids and derivatives thereof. Examples of unsaturated carboxylic acids include (meth)acrylic acid, maleic acid, fumaric acid, tetrahydrophthalic acid, itaconic acid, citraconic acid, crotonic acid, isocrotonic acid, norbornene dicarboxylic acid, and bicyclo[2.2.1]hept-2-ene-5,6-dicarboxylic acid. Among these, (meth)acrylic acid and maleic acid are preferred. One or more kinds of unsaturated carboxylic acids can be used.

[0072] Examples of the derivative of unsaturated carboxylic acid include the acid anhydride, acid halide, amide, imide, ester or salt of unsaturated carboxylic acid. Examples of the derivative of unsaturated carboxylic acid include maleic anhydride, itaconic anhydride, citraconic anhydride, tetrahydrophthalic anhydride, bicyclo[2.2.1]hept-2-ene-5,6-dicarboxylic anhydride, malenyl chloride, acrylamide, methacrylamide, maleylimide, dimethyl maleate, monomethyl maleate, diethyl maleate, monoethyl maleate, diethyl fumarate, dimethyl itaconate, diethyl citraconic acid, dimethyl tetrahydrophthalate, dimethyl bicyclo[2.2.1]hept-2-ene-5,6-dicarboxylate, alkyl(meth)acrylate, hydroxyethyl(meth)acrylate, hydroxypropyl(meth)acrylate, glycidyl(meth)acrylate, and ammonium salt or amine salt of unsaturated carboxylic acid. Among these, the acid anhydrides of unsaturated carboxylic acids are preferred, and maleic anhydride is more preferred. One or more derivatives of unsaturated carboxylic acids may be used.

[0073] Among the acid-modified olefin polymers, acid-modified polyethylene and acid-modified polypropylene are preferred, acid-modified polyethylene is more preferred, and maleic acid-modified polyethylene and maleic anhydride-modified polyethylene are even more preferred.

[0074] In the acid-modified olefin polymer, the total proportion of structural units derived from an acid component may be from 0.01% by mass to 25% by mass, from 0.1% by mass to 10% by mass, or from 0.5% by mass to 5% by mass.

[0075] In the acid-modified olefin polymer, the content of structural units derived from nonpolar monomers other than α-olefins may be, for example, 30% by mass or less, 20% by mass or less, or 10% by mass or less.

[0076] The weight average molecular weight (Mw) of the olefin polymer may be, for example, 5,000 or more and 150,000 or less, 10,000 or more and 100,000 or less, or 20,000 or more and 70,000 or less. When Mw is equal to or less than the upper limit, for example, the printing sensitivity of the first transfer layer can be further improved. When Mw is equal to or more than the lower limit, for example, the durability of the release layer can be further improved. In the present disclosure, Mw means a value measured by gel permeation chromatography using polystyrene as a standard substance, and is measured by a method conforming to JIS K7252-1.

[0077] From the viewpoint of coating film formability and releasability, the melting point (Tm) of the olefin polymer is preferably from 60° C. to 250° C., more preferably from 70° C. to 160° C., and even more preferably from 80° C. to 150° C. In the present disclosure, Tm is obtained by differential scanning calorimetry (DSC) in accordance with JIS K7121.

[0078] The acid value of the acid-modified olefin polymer is preferably 1 mgKOH / g or more and 200 mgKOH / g or less, more preferably 5 mgKOH / g or more and 100 mgKOH / g or less, and even more preferably 10 mgKOH / g or more and 50 mgKOH / g or less. In the present disclosure, the acid value is measured in accordance with JIS K0070. The olefin polymers can be used alone or in combination.

[0079] When preparing the coating liquid for the release layer, an aqueous dispersion (emulsion) of an olefin polymer may be used. The number average particle size of the olefin polymer particles in the emulsion is preferably 5 nm or more and 1,000 nm or less, more preferably 10 nm or more and 500 nm or less. The number average particle size is measured by a laser diffraction type particle size distribution measuring device.

[0080] Examples of vinyl alcohol polymers include polyvinyl alcohol and ethylene-vinyl alcohol copolymers, and also include modified products of polyvinyl alcohol, specifically polyvinyl formal, polyvinyl butyral, and polyvinyl acetals such as polyvinyl acetoacetal. Among these, polyvinyl alcohol is preferred.

[0081] Polyvinyl alcohol is a polymer obtained by completely or partially saponifying a vinyl ester polymer. Examples of the saponification method include an alkali saponification method and an acid saponification method. Among these, the method of alcoholysis using an alkali hydroxide in methanol is preferred.

[0082] The saponification rate of polyvinyl alcohol may be, for example, 80 mol % or more, 85 mol % or more, 90 mol % or more, or 95 mol % or more. The saponification rate of polyvinyl alcohol is measured in accordance with JIS K6726.

[0083] Examples of vinyl esters include vinyl formate, vinyl acetate, vinyl propionate, vinyl pivalate, and vinyl versatate. Of these, vinyl acetate is industrially preferred.

[0084] Other vinyl compounds may be copolymerized together with the vinyl ester. Examples of other vinyl compounds include unsaturated monocarboxylic acids such as (meth)acrylic acid and crotonic acid, as well as their esters, salts, anhydrides, amides, or nitriles; unsaturated dicarboxylic acids such as maleic acid, itaconic acid, and fumaric acid, as well as their salts; α-olefins having 2 to 30 carbon atoms; alkyl vinyl ethers; and vinylpyrrolidone. In polyvinyl alcohol, the content of the structural units derived from other vinyl compounds may be 10% by mass or less, 5% by mass or less, or 3% by mass or less.

[0085] The average degree of polymerization of the vinyl alcohol polymer may be, for example, 300 or more and 2,500 or less, or 400 or more and 2,500 or less. The vinyl alcohol polymers can be used alone or in combination.

[0086] The vinyl chloride-vinyl acetate copolymer means a copolymer having a structural unit derived from vinyl chloride and a structural unit derived from vinyl acetate, but the copolymer may have a structural unit derived from a compound other than vinyl chloride and vinyl acetate. By using the vinyl chloride-vinyl acetate copolymer together with the olefin polymer and the vinyl alcohol polymer, for example, the above-mentioned printing performance can be improved.

[0087] The content of structural units derived from vinyl chloride in the vinyl chloride-vinyl acetate copolymer may be 10% by mass or more and 90% by mass or less, 30% by mass or more and 85% by mass or less, or 40% by mass or more and 80% by mass or less.

[0088] The content of structural units derived from vinyl acetate in the vinyl chloride-vinyl acetate copolymer may be 10% by mass or more and 90% by mass or less, 15% by mass or more and 70% by mass or less, or 20% by mass or more and 60% by mass or less.

[0089] 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 10% by mass or less, 5% by mass or less, or 3% by mass or less.

[0090] The glass transition temperature (Tg) of the vinyl chloride-vinyl acetate copolymer is, for example, 40° C. or more and 90° C. or less, preferably 50° C. or more and 80° C. or less, and more preferably 55° C. or more and 70° C. or less. This can, for example, further improve the printing performance. Tg can be adjusted, for example, by the copolymerization ratio of vinyl chloride and vinyl acetate. In the present disclosure, Tg is obtained by differential scanning calorimetry (DSC) in accordance with JIS K7121.

[0091] The number average molecular weight (Mn) 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. This can, for example, further improve the primary transferability and secondary transferability. Also, it can improve the adhesion between the first transfer layer and the second transfer layer of the intermediate transfer medium or the transferee. In the present disclosure, Mn means a value measured by gel permeation chromatography using polystyrene as a standard substance, and is measured by a method conforming to JIS K7252-1.

[0092] The acid value of the vinyl chloride-vinyl acetate copolymer is preferably 1 mgKOH / g or more and 100 mgKOH / g or less, more preferably 2 mgKOH / g or more and 50 mgKOH / g or less, and even more preferably 5 mgKOH / g or more and 20 mgKOH / g or less. This can, for example, further stabilize the emulsion described below and further improve the durability of the release layer. In the present disclosure, the acid value is measured in accordance with JIS K0070. The vinyl chloride-vinyl acetate copolymer may be used alone or in combination.

[0093] When preparing the coating liquid for the release layer, an aqueous dispersion (emulsion) of vinyl chloride-vinyl acetate copolymer may be used. The number average particle size of the vinyl chloride-vinyl acetate copolymer particles in the emulsion is preferably 30 nm or more and 500 nm or less, more preferably 50 nm or more and 400 nm or less. The number average particle size is measured by a laser diffraction type particle size distribution measuring device.

[0094] Based on 100% by mass of the total mass of the release layer, the content of the olefin-based polymer is preferably 20% by mass or more and 90% by mass or less, more preferably 35% by mass or more and 85% by mass or less. When the content of the olefin-based polymer is equal to or more than the lower limit, for example, the adhesion between the substrate and the release layer can be further improved. The content of the olefin-based polymer is more preferably 45% by mass or more and 68% by mass or less, particularly preferably 55% by mass or more and 68% by mass or less. This can, for example, further suppress foil-fall of the first transfer layer, and further improve the balance of the printing performance, secondary transferability, and peeling force after storage of the thermal transfer sheet.

[0095] Based on the total mass of the release layer being 100 mass%, the content of the vinyl alcohol-based polymer is preferably 2 mass% or more and 40 mass% or less, more preferably 5 mass% or more and 30 mass% or less, even more preferably 5 mass% or more and 20 mass% or less, and particularly preferably 5 mass% or more and 15 mass% or less. When the content of the vinyl alcohol-based polymer is equal to or more than the lower limit, for example, the releasability of the first transfer layer can be improved. When the content of the vinyl alcohol-based polymer is equal to or less than the upper limit, for example, the foil drop of the first transfer layer can be suppressed and the secondary transferability can be improved.

[0096] Based on the total mass of the release layer being 100 mass%, the content of the vinyl chloride-vinyl acetate copolymer is preferably 5 mass% or more and 70 mass% or less, more preferably 10 mass% or more and 60 mass% or less. When the content of the vinyl chloride-vinyl acetate copolymer is equal to or more than the lower limit, for example, the printing performance can be further improved. When the content of the vinyl chloride-vinyl acetate copolymer is equal to or less than the upper limit, for example, the increase in the peeling force after storage of the thermal transfer sheet can be suppressed. The content of the vinyl chloride-vinyl acetate copolymer is more preferably 10 mass% or more and 45 mass% or less, particularly preferably 10 mass% or more and 35 mass% or less. This can, for example, further suppress foil-fall of the first transfer layer, and further improve the balance of the printing performance, secondary transferability, and peeling force after storage of the thermal transfer sheet.

[0097] In one embodiment, the release layer preferably does not contain a release agent such as a silicone compound, a fluorine compound, a wax, a surfactant, etc., or the content of the release agent is small, which can suppress, for example, the transfer of the release agent from the release layer to the first transfer layer, resulting in transfer failure during secondary transfer.

[0098] In the release layer, the total content of the silicone compound, the fluorine compound, the wax and the surfactant is preferably 2 parts by mass or less, more preferably 1 part by mass or less, even more preferably 0.5 parts by mass or less, and particularly preferably 0.1 parts by mass or less, per 100 parts by mass of the olefin polymer.

[0099] Examples of waxes include natural waxes such as beeswax, spermaceti, Japan wax, rice bran wax, carnauba wax, candelilla wax, and montan wax; synthetic waxes such as paraffin wax, microcrystalline wax, silicone wax, oxidized wax, ozokerite, ceresin, ester wax, and polyethylene 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 fatty acid esters of sorbitan; and higher fatty acid amides such as stearic acid amide and oleic acid amide.

[0100] Examples of the surfactant include cationic surfactants, anionic surfactants, nonionic surfactants, amphoteric surfactants, fluorine-based surfactants, and reactive surfactants.

[0101] In one embodiment, the release layer may contain one or more resin materials other than olefin-based polymers, vinyl alcohol-based polymers, and vinyl chloride-vinyl acetate copolymers (hereinafter also referred to as "other resin materials"). Examples of other resin materials include (meth)acrylic resins, vinyl resins, polyesters, polyamides, polyurethanes, thermally crosslinkable epoxy-amino resins, thermally crosslinkable alkyd-amino resins, melamine resins, urea resins, and cellulose resins. The content of other resin materials in the release layer may be 10% by mass or less, or 5% by mass or less.

[0102] The release layer may contain one or more additives, such as fillers, plasticizers, antistatic agents, UV absorbers, organic particles, inorganic particles, release agents, and dispersants.

[0103] The thickness of the release layer is preferably 0.1 μm or more and 3.0 μm or less, and more preferably 0.1 μm or more and 2.0 μm or less, which can, for example, further improve the transferability of the first transfer layer.

[0104] <Primer layer> In one embodiment, the thermal transfer sheet of the present disclosure includes a primer layer between the substrate and the release layer. When the thermal transfer sheet includes a sublimation transfer type color material layer as the second color material layer described later, the thermal transfer sheet may include a primer layer between the second color material layer and the substrate. This can improve the adhesion between these layers, for example.

[0105] In one embodiment, the primer layer contains one or more resin materials. Examples of the resin materials include polyester, vinyl resin, (meth)acrylic resin, polystyrene, polyamide, polyether, urethane resin, and cellulose resin. Among these, polyester is preferred from the viewpoint of adhesion between the substrate and the release layer.

[0106] The primer layer may contain one or more of the above additives. The thickness of the primer layer is, for example, not less than 0.05 μm and not more than 2.0 μm.

[0107] <Second Colorant Layer> In one embodiment, the thermal transfer sheet of the present disclosure further comprises a second color material layer on the surface of the substrate on which the first transfer layer is provided. In this embodiment, the second color material layer and the first transfer layer comprising the first color material layer are provided in surface sequence on one surface of the substrate. FIG. 3 shows an example of a thermal transfer sheet according to this embodiment. The thermal transfer sheet 1 comprises a substrate 10, a second color material layer 50 provided in surface sequence on one surface of the substrate 10, and a first transfer layer 20 including a first color material layer 22.

[0108] The second color material layer is used to form an image. The second color material layer contains a color material. The color material may be a pigment or a dye. The dye may be a sublimable dye.

[0109] The second color material layer may be a sublimation transfer type color material layer to which a sublimation color material such as a sublimation dye contained in the color material layer is transferred, or a melt transfer type color material layer to which the color material layer itself is transferred. The thermal transfer sheet may include both a sublimation transfer type color material layer and a melt transfer type color material layer.

[0110] For example, when the thermal transfer image is formed by a dye-sublimation thermal transfer method, the second color material layer is a sublimation transfer type color material layer containing a sublimation dye and a binder.

[0111] The sublimation dye preferably has sufficient coloring density and does not discolor or fade due to light, heat, etc. Examples of such sublimation dyes include red dyes, yellow dyes, and blue dyes. The sublimation transfer color material layer can contain one or more sublimation dyes. The content of the sublimation dye in the sublimation transfer color material layer is preferably 5% by mass or more and 80% by mass or less, more preferably 10% by mass or more and 70% by mass or less.

[0112] Examples of the binder in the sublimation transfer colorant layer include resin materials such as cellulose resin, vinyl resin, vinyl acetal resin, (meth)acrylic resin, urethane resin, polyamide, polyimide, and polyester. The sublimation transfer colorant layer can contain one or more binders. The content of the binder in the sublimation transfer colorant layer is preferably 20% by mass or more and 75% by mass or less, more preferably 30% by mass or more and 60% by mass or less.

[0113] The sublimation transfer color material 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.

[0114] For example, when a thermal transfer image is formed by a melting type thermal transfer method, the second color material layer is a melting transfer type color material layer containing a color material and a binder.

[0115] The coloring material preferably has sufficient coloring density and does not discolor or fade due to light, heat, or the like. Examples include organic pigments, inorganic pigments, and dyes. The color of the coloring material is not limited to, for example, cyan, magenta, yellow, or black, and may be any of a variety of colors. The melt-transfer coloring material layer may contain one or more types of coloring material. The content of the coloring material in the melt-transfer coloring material layer is preferably 10% by mass or more and 60% by mass or less, more preferably 20% by mass or more and 50% by mass or less.

[0116] Examples of the binder in the melt-transfer colorant layer include resin materials such as polyolefin, vinyl resin, vinyl acetal resin, (meth)acrylic resin, polystyrene, polycarbonate, cellulose resin, and petroleum resin. The melt-transfer colorant layer can contain one or more binders. The content of the binder in the melt-transfer colorant layer is preferably 20% by mass or more and 75% by mass or less, more preferably 30% by mass or more and 60% by mass or less.

[0117] The melt transfer type color material layer may further contain a conventionally known wax. The second color material layer may contain one or more of the above additives.

[0118] The thermal transfer sheet of the present disclosure may have one second colorant layer on one side of the substrate, or may have a plurality of second colorant layers of different hues, for example, a yellow colorant layer, a magenta colorant layer, a cyan colorant layer and a black colorant layer, arranged in face-sequential order.

[0119] In one embodiment, the thermal transfer sheet of the present disclosure includes a dye layer consisting of a yellow (Y) layer, a magenta (M) layer, and a cyan (C) layer provided on one surface of a substrate, a black (BK) melt-transfer type colorant layer, and a first transfer layer including a first colorant layer such as a metal-based pigment-containing layer. In one embodiment of the thermal transfer sheet of the present disclosure, the Y layer, the M layer, the C layer, the BK layer, and the first transfer layer including a first colorant layer such as a metal-based pigment-containing layer are provided in surface order on the substrate (see FIG. 4). The release layer is provided between the substrate and the first transfer layer. The release layer may be provided between the substrate and the BK layer.

[0120] The thickness of the second color material layer is, for example, 0.1 μm or more and 30.0 μm or less, preferably 0.1 μm or more and 20.0 μm or less, and more preferably 0.1 μm or more and 10.0 μm or less.

[0121] <Back layer> In one embodiment, the thermal transfer sheet may include a back layer on the surface of the substrate opposite to the first transfer layer, which can, for example, prevent sticking and wrinkles caused by heating during thermal transfer.

[0122] In one embodiment, the back layer contains one or more resin materials. Examples of the resin materials include polyolefin, polystyrene, vinyl resin, (meth)acrylic resin, vinyl acetal resin such as polyvinyl butyral and polyvinyl acetoacetal, silicone resin, (meth)acrylic modified silicone resin, polyester, polyamide, polyimide, urethane resin, and cellulose resin. The content of the resin material in the back layer is preferably 10% by mass or more, more preferably 15% by mass or more.

[0123] The back layer may be a layer formed by crosslinking a resin material having a reactive group such as a hydroxyl group using a crosslinking agent such as polyisocyanate. Examples of polyisocyanates include xylylene diisocyanate, toluene diisocyanate, isophorone diisocyanate, and hexamethylene diisocyanate. One or more types of crosslinking agents can be used.

[0124] The back layer may contain one or more types of release agents. Examples of the release agents include fluorine compounds, phosphate compounds, higher fatty acid amide compounds, metal soaps, silicone oils, and waxes such as polyethylene wax and paraffin wax. This can improve, for example, slip properties. The content of the release agent in the back layer is preferably 0.5% by mass or more and 20% by mass or less, more preferably 0.5% by mass or more and 12% by mass or less.

[0125] The back layer may contain one or more of the above additives.

[0126] The thickness of the back layer is preferably from 0.1 μm to 5.0 μm, more preferably from 0.3 μm to 3.0 μm, which can suppress, for example, sticking and print wrinkles caused by heating during thermal transfer.

[0127] [Intermediate transfer medium] The thermal transfer sheet of the present disclosure is preferably used together with an intermediate transfer medium. The intermediate transfer medium comprises a support and a second transfer layer provided on the support. More specifically, the intermediate transfer medium comprises a support and a second transfer layer provided on one side of the support so as to be peelable from the support.

[0128] <Support> As the support, the same materials as the above-mentioned base material can be used.

[0129] <Second transfer layer> In one embodiment, the second transfer layer comprises a receiving layer. The second transfer layer may have a single-layer structure made of a receiving layer, or may have a multi-layer structure made of a receiving layer and other layers. When the second transfer layer has a multi-layer structure, the receiving layer constitutes the surface layer on the opposite side of the support in the second transfer layer.

[0130] In one embodiment, the second transfer layer includes a release layer and a receiving layer in this order in the thickness direction from the support side. In one embodiment, the second transfer layer includes a release layer, a protective layer, and a receiving layer in this order in the thickness direction from the support side.

[0131] (Receptive layer) In one embodiment, the receptor layer constitutes a surface layer on one side of the intermediate transfer medium. For example, a thermal transfer sheet of the present disclosure having a first colorant layer is used to form a thermal transfer image on a receiving layer, and then a second transfer layer including this receiving layer is transferred onto any receiving body, thereby obtaining a printed matter having a second transfer layer including a receiving layer on which a thermal transfer image has been formed, on the receiving body.

[0132] In one embodiment, the receiving layer contains one or more resin materials. Examples of the resin materials include polyolefins such as polyethylene and polypropylene, vinyl resins such as polyvinyl chloride, polyvinyl acetate, and vinyl chloride-vinyl acetate copolymers, polyesters such as polyethylene terephthalate and polyethylene naphthalate, polystyrene, (meth)acrylic resins, polyamides, polyimides, polycarbonates, urethane resins, cellulose resins, and ionomer resins. Among these, vinyl chloride-vinyl acetate copolymers and polyesters are preferred.

[0133] The content of the resin material in the receiving layer is preferably from 80% by mass to 99% by mass, and more preferably from 85% by mass to 98% by mass.

[0134] In one embodiment, the receiving layer contains one or more types of release agents, which can improve the releasability between the receiving layer and the thermal transfer sheet, for example.

[0135] Examples of the release agent include fluorine compounds, phosphoric acid ester compounds, higher fatty acid amide compounds, metal soaps, silicone oils, and waxes such as polyethylene wax and paraffin wax. Among these, silicone oils are preferred from the viewpoint of the above-mentioned release properties.

[0136] Examples of silicone oils include straight silicone oils such as dimethyl silicone oil and methylphenyl silicone oil, and modified silicone oils such as amino-modified silicone oil, epoxy-modified silicone oil, carboxy-modified silicone oil, (meth)acrylic-modified silicone oil, mercapto-modified silicone oil, carbinol-modified silicone oil, fluorine-modified silicone oil, methylstyryl-modified silicone oil, and polyether-modified silicone oil. Modified silicone oils include one-end type, both-end type, and side chain one-end type.

[0137] The content of the release agent in the receiving layer is preferably from 0.5% by mass to 20% by mass, more preferably from 0.5% by mass to 10% by mass, which can improve, for example, the releasability.

[0138] The receiving layer may contain one or more additives. Examples of additives include plasticizers, UV absorbers, inorganic particles, organic particles, and dispersants. The content of the additives relative to 100 parts by mass of the resin material contained in the receiving layer is preferably 0.1 parts by mass or more and 20 parts by mass or less, more preferably 0.5 parts by mass or more and 10 parts by mass or less.

[0139] The thickness of the receptor layer is preferably 0.5 μm or more and 20.0 μm or less, more preferably 1.0 μm or more and 10.0 μm or less, which can improve, for example, the density of the thermal transfer image formed on the receptor layer.

[0140] (Release layer) In one embodiment, the second transfer layer of the intermediate transfer medium has a release layer as a surface layer on the support side. This can improve the release property of the second transfer layer from the support when transferring the second transfer layer from the intermediate transfer medium. The release layer is a layer that is transferred from the intermediate transfer medium onto the transferee.

[0141] In one embodiment, the release layer contains one or more resin materials, such as polyolefins, vinyl resins, polystyrene, (meth)acrylic resins, polyesters, polyamides, polyimides, polycarbonates, cellulose resins, and ionomer resins.

[0142] The release layer may contain one or more of the above-mentioned release agents. The release layer may contain one or more of the above additives.

[0143] The thickness of the release layer is preferably 0.1 μm or more and 8.0 μm or less, and more preferably 0.5 μm or more and 5.0 μm or less, which can, for example, further improve the durability of the release layer.

[0144] (protective layer) In one embodiment, the second transfer layer of the intermediate transfer medium comprises a protective layer on the support side of the receiving layer, or between the release layer and the receiving layer.

[0145] In one embodiment, the protective layer contains one or more resin materials, such as polyester, polystyrene, urethane resin, (meth)acrylic resin, and (meth)acrylic polyol resin. The protective layer may contain one or more of the above additives.

[0146] The thickness of the protective layer is preferably 0.5 μm or more and 7.0 μm or less, and more preferably 1.0 μm or more and 5.0 μm or less, which can, for example, further improve the durability of the protective layer.

[0147] [Manufacturing method of printed matter] The method for producing a print product of the present disclosure includes a step of preparing the thermal transfer sheet and intermediate transfer medium of the present disclosure (preparation step), a step of transferring a first transfer layer of the thermal transfer sheet onto a second transfer layer of the intermediate transfer medium (primary transfer step), and a step of transferring the second transfer layer onto which the first transfer layer has been transferred from the intermediate transfer medium onto a recipient (secondary transfer step).

[0148] <Preparation process> The method for producing a print according to the present disclosure includes the steps of preparing a thermal transfer sheet and an intermediate transfer medium. The thermal transfer sheet and the intermediate transfer medium are as described above, and therefore will not be described here.

[0149] (Primary transfer process) The method for producing a print of the present disclosure includes a step (primary transfer step) of transferring a first transfer layer of a thermal transfer sheet onto a second transfer layer of an intermediate transfer medium. When the first transfer layer includes a first color material layer, an image can be formed on the second transfer layer of the intermediate transfer medium, particularly on the receiving layer. The transfer can be performed by a conventionally known method using a thermal transfer printer or the like equipped with a thermal head.

[0150] Specifically, the first transfer layer of the thermal transfer sheet is brought into contact with the surface of the second transfer layer of the intermediate transfer medium, and then heat is applied to a desired area of ​​the thermal transfer sheet to transfer the first transfer layer of the desired area onto the second transfer layer of the intermediate transfer medium. In one embodiment, the thermal transfer sheet and the intermediate transfer medium are superimposed and passed between a thermal head and a platen roller of a thermal transfer printer, and the thermal transfer sheet is heated by the thermal head, thereby performing the above transfer.

[0151] (Secondary transfer process) The method for producing a print of the present disclosure includes a step of transferring the second transfer layer onto a transferee from the intermediate transfer medium (secondary transfer step). The transfer can be performed by a conventionally known method using a commercially available thermal transfer printer or the like.

[0152] Examples of the transfer-receiving body include the above-mentioned resin film, glass substrate, metal substrate, ceramic substrate, cloth substrate, and paper substrate, as well as laminated substrates thereof, which are described as substrates in the thermal transfer sheet. The transfer-receiving body may be a card substrate. Examples of the cloth substrate include substrates formed from fibers such as man-made 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, hemp, and wool. Examples of the paper substrate include fine paper, plain paper, art paper, coated paper, resin-coated paper, cast-coated paper, paperboard, synthetic paper, and impregnated paper.

[0153] According to the method for producing a print of the present disclosure, for example, an image composed of characters, line drawings, patterns, symbols, and combinations thereof can be formed on a receiving body.

[0154] The present disclosure relates to, for example, the following [1] to

[10] . [1] A thermal transfer sheet comprising a substrate and a first transfer layer provided on the substrate, the thermal transfer sheet comprising a release layer between the substrate and the first transfer layer, the release layer containing an olefin-based polymer, a vinyl alcohol-based polymer, and a vinyl chloride-vinyl acetate copolymer. [2] The thermal transfer sheet according to the above [1], wherein the olefin polymer is an acid-modified olefin polymer. [3] The thermal transfer sheet according to [1] or [2] above, wherein the content of the olefin polymer is 20% by mass or more and 90% by mass or less, and the content of the vinyl alcohol polymer is 2% by mass or more and 40% by mass or less, based on 100% by mass of the total mass of the release layer. [4] The thermal transfer sheet according to any one of the above [1] to [3], wherein the content of vinyl chloride-vinyl acetate copolymer is 5% by mass or more and 70% by mass or less, based on 100% by mass of the total mass of the release layer. [5] The thermal transfer sheet according to any one of the above [1] to [4], wherein the first transfer layer comprises a first color material layer. [6] The thermal transfer sheet according to the above [5], wherein the first color material layer contains at least one selected from vinyl chloride-vinyl acetate copolymer and polyester. [7] The thermal transfer sheet according to [5] or [6] above, wherein the first transfer layer further comprises a release layer, and the release layer constitutes a surface layer of the first transfer layer on the substrate side. [8] The thermal transfer sheet according to any one of the above [1] to [7], which is used in combination with an intermediate transfer medium comprising a support and a second transfer layer provided on the support. [9] The thermal transfer sheet described in [8] above, wherein the second transfer layer has a receiving layer, and the receiving layer contains at least one selected from vinyl chloride-vinyl acetate copolymer and polyester.

[10] A method for producing a printed matter, comprising the steps of: preparing an intermediate transfer medium comprising the thermal transfer sheet described in any one of [1] to [9] above, a support, and a second transfer layer provided on the support; transferring the first transfer layer provided on the thermal transfer sheet onto the second transfer layer provided on the intermediate transfer medium; and transferring the second transfer layer onto which the first transfer layer has been transferred from the intermediate transfer medium onto a recipient. EXAMPLES

[0155] The thermal transfer sheet of the present disclosure will be described in more detail below with reference to examples, but the thermal transfer sheet of the present disclosure is not limited to these examples. In the following description, "parts" means "parts by mass". The blending amounts shown in the following description and Table 1 are values ​​calculated as solids, excluding water and organic solvents.

[0156] [Example 1] A PET film having a thickness of 6 μm was used as the substrate. A release layer coating liquid having the following composition was applied on one side of the substrate and dried to form a release layer having a thickness of 0.2 μm. A metal-based pigment-containing layer coating liquid having the following composition was applied on the release layer and dried to form a metal-based pigment-containing layer having a thickness of 0.7 μm. A back layer coating liquid having the following composition was applied on the other side of the substrate and dried to form a back layer having a thickness of 0.8 μm. In this way, a thermal transfer sheet was obtained. The first transfer layer of the thermal transfer sheet is composed of a metal-based pigment-containing layer.

[0157] <Release layer coating fluid> Acid-modified olefin polymer (olefin-based polymer) 8 parts (Arrowbase (registered trademark) SD-1205J2, water-based emulsion, Unitika Co., Ltd. 1 part polyvinyl alcohol (Kuraray Poval (registered trademark) PVA-103, Kuraray Co., Ltd.) Vinyl chloride-vinyl acetate copolymer 1 part (Vinybran (registered trademark) 603, Tg 63°C, acid value 12 mg KOH / g, Water-based emulsion, Nissin Chemical Industry Co., Ltd. ·Water 100 parts 100 parts isopropyl alcohol

[0158] <Coating fluid for metallic pigment-containing layer> Aluminum pigment (Al pigment) 20 parts (FD-5060, average particle size 6 μm, hiding power 3.4, Non-leafing type, Asahi Kasei Corporation) Vinyl chloride-vinyl acetate copolymer 40 parts (Solvine (registered trademark) CNL, Nissin Chemical Industry Co., Ltd.) Methyl ethyl ketone (MEK) 30 parts Toluene 30 parts

[0159] <Coating fluid for back layer> Acrylic modified silicone resin 10 parts (Polyalloy NSA-X55, Natoco Co., Ltd.) ·MEK 20 copies

[0160] [Examples 2 to 8 and Comparative Examples 1 to 3] A thermal transfer sheet was produced in the same manner as in Example 1, except that the type and amount ratio of the resin material in the release layer was changed as shown in Table 1. In Table 1, the relative amount of each resin material per 100 parts of the resin material is shown. The materials used are described below. (Meth)acrylic resin: Vinyblan (registered trademark) 2585, Nissin Chemical Industry Co., Ltd. Polyester: Elitel (registered trademark) KA-1449, Unitika Co., Ltd.

[0161] [Preparation of intermediate transfer medium] A PET film having a thickness of 12 μm was prepared. A release layer coating liquid having the following composition was applied to one side of the PET film and dried to form a release layer having a thickness of 1.6 μm. A protective layer coating liquid having the following composition was applied to the release layer and dried to form a protective layer having a thickness of 4.7 μm. A receiving layer coating liquid having the following composition was applied to the protective layer and dried to form a receiving layer having a thickness of 2.0 μm. In this manner, an intermediate transfer medium was obtained. The second transfer layer in the intermediate transfer medium is composed of a release layer, a protective layer, and a receiving layer.

[0162] <Coating solution for release layer> (Meth)acrylic resin 20 parts (Dianal (registered trademark) BR-83, Mitsubishi Chemical Corporation) 1 part polyester (Vylon (registered trademark) 600, Toyobo Co., Ltd.) ·MEK 79 copies

[0163] <Coating solution for protective layer> 20 parts polyester (Vylon (registered trademark) GK-250, Toyobo Co., Ltd.) ·MEK 80 copies

[0164] <Coating solution for receiving layer> Vinyl chloride-vinyl acetate copolymer 20 parts (Solvine (registered trademark) CNL, Nissin Chemical Industry Co., Ltd.) 1 part silicone oil (X-22-3000T, Shin-Etsu Chemical Co., Ltd.) ·MEK 79 copies

[0165] [Production of printed matter] Using the test printer described below, the first transfer layer of the thermal transfer sheet prepared in the examples or comparative examples was transferred onto the receiving layer in the second transfer layer of the intermediate transfer medium prepared above, thereby obtaining a primary transfer product.

[0166] (Test Printer) Thermal head: Kyocera Corporation, KEE-57-12GAN2-STA Heating element average resistance: 3303Ω - Main scanning resolution: 300 dpi (dot per inch) Sub-scanning resolution: 300 dpi Line speed: 3.0msec. / line ·Printing start temperature: 35℃ Pulse Duty Ratio: 70%

[0167] The second transfer layer of the intermediate transfer medium and the transferred first transfer layer were retransferred onto a polyvinyl chloride card under the following retransfer conditions to obtain a secondary transfer product.

[0168] (Retransfer conditions) Laminator: Lamipacker LPD3212 (manufactured by Fujipla) ·Temperature: 175℃ ·Speed: 40mm / s

[0169] [Evaluation of adhesion of the first transfer layer on the thermal transfer sheet before thermal transfer] An adhesive tape (Scotch mending tape (18 mm wide) manufactured by Sumitomo 3M) was attached to the surface of the first transfer layer of the thermal transfer sheet produced in the examples or comparative examples with a length of 30 mm. After leaving it for 1 minute, the adhesive tape was peeled off from the thermal transfer sheet under the condition of 180 degrees peeling over 0.5 to 1.0 seconds. The peeling state of the first transfer layer at this time was confirmed, and the adhesion was evaluated according to the following criteria. A: There is no peeled portion of the first transfer layer. B: The first transfer layer was slightly peeled off. C: The first transfer layer peeled off over an area of ​​50% or more, but did not come off even when rubbed with the hand. NG: The first transfer layer peels off easily from the substrate.

[0170] [Printing performance: Evaluation of fine line printability] In the preparation of the above primary transfer product, the characters printed on the receptor layer in the second transfer layer of the intermediate transfer medium were visually observed and evaluated for fine line printability according to the following criteria. A: Fine line printability is good. B: Usable depending on the energy applied during thermal transfer. C: The printed characters are slightly thick. NG: The printed characters are connected to each other.

[0171] [Printing performance: Evaluation of thermal trail] Using the above test printer, the first transfer layer of the thermal transfer sheet prepared in the Examples or Comparative Examples was printed solidly on half the area of ​​the receiving layer in the second transfer layer of the intermediate transfer medium prepared above. Transfer outside the half area of ​​the receiving layer due to heat accumulation in the thermal head was observed, and thermal trailing was evaluated according to the following criteria. A: No thermal tailing was observed. B: A slight heat trail was observed. C: Significant heat trailing was observed. NG: The entire area outside the transfer area was transferred.

[0172] [Evaluation of adhesion (secondary transferability) in secondary transfer material] A 30 mm long adhesive tape (Sumitomo 3M's Scotch mending tape (18 mm wide)) was attached to the surface of the transfer layer of the secondary transfer product. After leaving it for 1 minute, the adhesive tape was peeled off from the secondary transfer product under 180 degree peeling conditions over 0.5 to 1.0 seconds. The peeling state of the transfer layer at this time was confirmed, and the adhesion was evaluated according to the following criteria. A: There is no peeled portion of the transfer layer. B: The peeled portion of the transfer layer was less than 20%. C: The peeled portion of the transfer layer was 20% or more and less than 50%. NG: Peeling of the transfer layer was 50% or more.

[0173] [Evaluation of peel strength after storage] The thermal transfer sheets prepared in the Examples and Comparative Examples were stored for 48 hours under conditions of 50°C and 20% RH. Using the following test printer, the first transfer layer of the thermal transfer sheet before and after storage was transferred onto the receiving layer of the second transfer layer of the intermediate transfer medium prepared above, to obtain a primary transfer product. Here, the peeling force when peeling the thermal transfer sheet from the intermediate transfer medium was measured under the following measurement conditions. (Test Printer) Thermal head: Kyocera Corporation, KEE-57-12GAN2-STA Heating element average resistance: 3303Ω - Main scanning resolution: 300 dpi Sub-scanning resolution: 300 dpi 1 line cycle: 2.0msec. ·Printing start temperature: 35℃ Applied voltage: 22V

[0174] (Peel force measurement conditions) Using a surface property measuring device (HEIDON-14, Shinto Scientific Co., Ltd.), the thermal transfer sheet was pulled horizontally at 2000 mm / min and peeled off at 180 degrees, and the peeling force at that time was measured. A: The peel strength after storage was 1.0 to 1.3 times that before storage. B: The peel strength after storage was more than 1.3 times but not more than 2.0 times that before storage. C: The peel strength after storage was more than 2.0 times but not more than 3.0 times that before storage. NG: The peel force after storage was more than 3.0 times that before storage.

[0175] [Table 1] [Explanation of symbols]

[0176] 1: Thermal transfer sheet 10: Base material 20: First transfer layer 22: First color material layer 24: Release layer 30: Release layer 40: Back layer 50: Second colorant layer

Claims

1. A thermal transfer sheet comprising a substrate and a first transfer layer provided on the substrate, the thermal transfer sheet includes a release layer between the substrate and the first transfer layer, The release layer contains an olefin-based polymer, a vinyl alcohol-based polymer, and a vinyl chloride-vinyl acetate copolymer. Thermal transfer sheet.

2. The thermal transfer sheet according to claim 1 , wherein the olefin polymer is an acid-modified olefin polymer.

3. 3. The thermal transfer sheet according to claim 1, wherein the content of the olefin-based polymer is 20% by mass or more and 90% by mass or less, and the content of the vinyl alcohol-based polymer is 2% by mass or more and 40% by mass or less, based on a total mass of 100% by mass of the release layer.

4. The thermal transfer sheet according to any one of claims 1 to 3, wherein the content of the vinyl chloride-vinyl acetate copolymer is 5% by mass or more and 70% by mass or less, based on 100% by mass of the total mass of the release layer.

5. The thermal transfer sheet according to any one of claims 1 to 4, wherein the first transfer layer comprises a first colorant layer.

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

7. The thermal transfer sheet according to claim 5 or 6, wherein the first transfer layer further comprises a release layer, the release layer constituting a surface layer of the first transfer layer on the substrate side.

8. The thermal transfer sheet according to any one of claims 1 to 7, which is used in combination with an intermediate transfer medium comprising a support and a second transfer layer provided on the support.

9. the second transfer layer comprises a receptor layer; The receiving layer contains at least one selected from vinyl chloride-vinyl acetate copolymer and polyester. The thermal transfer sheet according to claim 8.

10. A step of preparing an intermediate transfer medium comprising the thermal transfer sheet according to any one of claims 1 to 9, a support, and a second transfer layer provided on the support; transferring the first transfer layer of the thermal transfer sheet onto the second transfer layer of the intermediate transfer medium; transferring the second transfer layer onto which the first transfer layer has been transferred from the intermediate transfer medium onto a transfer-receiving body; A method for producing a printed matter comprising the steps of:

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