JP2023049776A - Thermal transfer sheet and method for manufacturing printed matter - Google Patents

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 The present disclosure relates to methods of making thermal transfer sheets and prints.

Conventionally, a thermal transfer method is used as a simple printing method. In the thermal transfer method, a thermal transfer sheet provided with a coloring material layer on one side of a substrate and a thermal transfer image receiving sheet provided with an image receiving layer as necessary are superimposed, and thermal transfer is performed by a heating means such as a thermal head. In this method, an image (thermal transfer image) is formed on the thermal transfer image-receiving sheet by heating the back surface of the sheet imagewise.

Thermal transfer methods are classified into a melt transfer method and a sublimation transfer method.
An image formed by the melt transfer method has high density and excellent sharpness. Therefore, the fusion transfer method is suitable for recording binary images such as characters. Since the sublimation transfer method can control the transfer amount of the sublimation dye according to the amount of energy applied, it is possible to form a gradation image in which the image density is controlled for each dot of the thermal head. In the sublimation transfer method, a thermal transfer sheet having layers of different colored materials such as yellow, magenta, cyan, and black is used. It is possible to form high-quality photographic full-color images.

However, the formed image may have poor durability. In order to solve this problem, it has been proposed to transfer the protective layer onto the image using a thermal transfer sheet having a base material and a protective layer provided to be peelable from the base material (for example, Patent Document 1). reference).

JP 2008-238525 A

From the viewpoint of further improving the durability of the printed matter by the protective layer, the present disclosure proposes that after the protective layer is thermally transferred so as to cover at least the thermally transferred image, the protective layer is further transferred onto the transferred protective layer. That is, the inventors have considered transferring the protective layer two or more times onto the thermally transferred image. However, the present inventors have found that when a protective layer is further transferred onto the transferred protective layer, print wrinkles may occur in the resulting print.

An object of the present disclosure is to provide a thermal transfer sheet capable of transferring a protective layer two or more times onto the same transfer-receiving material and capable of suppressing the occurrence of print wrinkles in the resulting print.

The thermal transfer sheet of the present disclosure includes a substrate, at least one colorant layer, and a transferable protective layer, and the colorant layer and the protective layer are provided on one surface of the substrate in a frame-sequential manner. , the length of the protective layer is at least twice the screen length of the colorant layer, and the dynamic friction coefficient between the surface of the protective layer opposite to the substrate and the surface of the protective layer on the substrate side is 0 0.34 or more and 0.85 or less.

According to the present disclosure, it is possible to provide a thermal transfer sheet capable of transferring a protective layer two or more times onto the same transfer-receiving material and capable of suppressing the occurrence of print wrinkles in the resulting print.

FIG. 1 is a schematic cross-sectional view of a thermal transfer sheet of the present disclosure according to one embodiment. FIG. 2 is a schematic cross-sectional view of a thermal transfer sheet of the present disclosure in one embodiment. FIG. 3 is a schematic cross-sectional view showing an example of a printed matter when a protective layer is transferred onto a transfer target using the thermal transfer sheet of the present disclosure according to one embodiment. FIG. 4 is a schematic cross-sectional view showing an example of a printed matter when a protective layer is transferred onto a transfer target using the thermal transfer sheet of the present disclosure of one embodiment. FIG. 5 is a schematic top view of a thermal transfer sheet of the present disclosure in one embodiment. FIG. 6 is a schematic top view of a thermal transfer sheet of the present disclosure in one embodiment. FIG. 7 is a schematic cross-sectional view of a thermal transfer sheet of the present disclosure in one embodiment. FIG. 8 is a schematic top view of a thermal transfer sheet of the present disclosure in one embodiment.

Hereinafter, embodiments of the present disclosure will be described in detail. This disclosure may be embodied in many different forms and should not be construed as limited to the description of the illustrative embodiments below. In order to make the description clearer, the drawings may schematically represent the width, thickness, shape, etc. of each layer compared to the embodiment, but this is only an example and does not limit the interpretation of the present disclosure. . In this specification and each figure, elements similar to those already described with respect to previous figures may be denoted by the same reference numerals, and detailed description thereof may be omitted as appropriate.

[Thermal transfer sheet]
The thermal transfer sheet of the present disclosure is
It comprises a substrate, at least one coloring material layer, and a transferable protective layer.
The coloring material layer and the transferable protective layer are provided on one surface of the substrate in a frame-sequential manner.

A "transferable protective layer" means a protective layer that is peeled off from a base material and transferred onto a transferred material by applying energy such as thermal energy to the back surface of the thermal transfer sheet. That is, the transferable protective layer constitutes a transfer layer that can be peeled off by application of energy in the thermal transfer sheet. Hereinafter, the transferable protective layer is also simply referred to as "protective layer".

The protective layer, in one embodiment, comprises a release layer and an adhesive layer from the substrate side. That is, in one embodiment, the protective layer includes a release layer and an adhesive layer provided on the surface of the release layer opposite to the substrate. The adhesive layer, in one embodiment, contacts the substrate when the protective layer is first transferred onto the substrate. In one embodiment, the release layer constitutes the surface layer of the printed matter obtained when the protective layer is transferred onto the transfer material for the second time, for example.

The thermal transfer sheet 1 of the embodiment shown in FIG. and a backing layer 40 provided on the . The thermal transfer sheet 1 of the embodiment shown in FIG. 2 is the same as the thermal transfer sheet 1 of the embodiment shown in FIG. The thermal transfer sheet 1 of the embodiment shown in FIGS. 1 and 2 may further include a release layer (not shown) located between the base material 10 and the protective layer 20 . In the thermal transfer sheet 1 of the embodiment shown in FIGS. 1 and 2, the back layer 40 may be omitted.

When the thermal transfer sheet 1 of the embodiment shown in FIGS. 1 and 2 is used to form an image on a transfer material 50 and then the protective layer 20 is transferred twice on the image, the results are as shown in FIGS. 3 and 4, respectively. , a printed material comprising a transfer-receiving body 50, an image (not shown) formed on the transfer-receiving body 50, and two protective layers 20, 20 provided on the transfer-receiving body 50 so as to cover the image; 2 is obtained. The protective layer 20 can satisfactorily protect an image (not shown) included in the printed matter 2 .

A combination of at least one colorant layer and a protective layer provided in a frame-sequential manner with respect to the colorant layer is called a "unit" (U). In the thermal transfer sheet of the present disclosure, one unit may be repeated on one side of a long base material, that is, a plurality of units may be provided in sequence in the longitudinal direction of the base material. FIG. 5 shows a top view of the thermal transfer sheet of one embodiment. In the thermal transfer sheet 1 of the embodiment shown in FIG. 5, a plurality of units (U) consisting of the coloring material layer 30 and the protective layer 20 are provided in the longitudinal direction of the substrate in a plane-sequential manner.

In the thermal transfer sheet of the present disclosure, the length of the protective layer is at least twice the screen length of the colorant layer. As shown in FIG. 5, the "screen length of the coloring material layer" means the length L1 of one coloring material layer 30 in the longitudinal direction (flow direction) of the thermal transfer sheet 1 when the thermal transfer sheet 1 is viewed from above. means. The “length of the protective layer” means the length L2 of the protective layer 20 in the longitudinal direction (flow direction) of the thermal transfer sheet 1 when the thermal transfer sheet 1 is viewed from above, as shown in FIG. “Screen size” means the area of one coloring material layer 30 on the thermal transfer sheet 1 .

The length of the protective layer is at least twice the screen length of the colorant layer, preferably from 2 to 10 times, more preferably from 2 to 5 times, still more preferably from 2 to 3 times. . In one embodiment of the thermal transfer sheet of the present disclosure, the size (area) of one protective layer is 2 times or more the screen size, preferably 2 times or more and 10 times or less, more preferably 2 times or more and 5 times or less. , more preferably 2 times or more and 3 times or less. That is, the thermal transfer sheet of the present disclosure can transfer the protective layer for at least two times the size of the screen. As a result, the same thermal transfer sheet can be used to transfer the protective layer two or more times onto the same thermal transfer image on the transfer material.

The protective layer, in one embodiment, 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 longer than the screen length of the colorant layer. In one embodiment, the area of each of the one color material layer, the protective layer in the first region, and the protective layer in the second region is approximately the same, and the entire surface (screen size) of the transfer-receiving body to be transferred is It's size.

In the protective layer, the first region and the second region are positioned in a frame-sequential manner. The first region and the second region may be continuous. That is, there is no other area between the first area and the second area, the first area and the second area are virtual areas, and there is a boundary separating them. No need. In the thermal transfer sheet 1 of the embodiment shown in FIG. 6, the hatched area indicated by reference numeral 20a is the first area, and the hatched area indicated by reference numeral 20b is the second area. 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. The protective layer including the first region and the second region may be a layer formed using one protective layer coating solution.

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 this case, the same thermal transfer sheet can be used to transfer the protective layer three times or more onto the same transfer material.

Image formation in which a thermal transfer sheet is used to thermally transfer the coloring material layer of the thermal transfer sheet to an object to be transferred 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 in the method, the protective layer can be transferred two or more times to the same transfer substrate. That is, two or more protective layers can be laminated on the same image. As a result, it is possible to obtain a thermally transferred image having excellent durability even under severe conditions of use, and to suppress the occurrence of wrinkles in the printed image as will be described later.

<Base material>
As the base material, if it has heat resistance to withstand the thermal energy when the protective layer is transferred from the thermal transfer sheet onto the transferred material, and mechanical strength and solvent resistance to support the protective layer, Can be used without any restrictions.

Examples of the substrate include a resin film made of a resin material. Examples of resin materials include polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), polyethylene terephthalate-isophthalate copolymer, and terephthalic acid-cyclohexanedimethanol-ethylene glycol copolymer. polyesters; 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 copolymers; ) (meth)acrylic resins such as acrylates; polyimides; polycarbonates; Styrene resins such as acrylonitrile-styrene copolymers and acrylonitrile-butadiene-styrene copolymers; cellulose resins such as cellophane, cellulose acetate and nitrocellulose. Among resin films, resin films made of polyester such as PET and PEN are preferable from the viewpoint of excellent heat resistance and mechanical strength.
The resin film can contain one or more resin materials.

In the present disclosure, "(meth)acrylate" includes both "acrylate" and "methacrylate", and "(meth)acryl" includes both "acryl" and "methacryl".

The substrate can be, for example, a paper substrate such as glassine paper, condenser paper and paraffin paper.

The substrate may be a laminate comprising multiple layers. As the substrate, for example, a laminate of resin films may be used. A laminate of resin films can be produced by using, for example, a dry lamination method, a wet lamination method, or an extrusion method. The substrate may be a stretched film, an unstretched film, or a uniaxially or biaxially stretched film from the viewpoint of improving strength.
The substrate, in one embodiment, is elongated.

The thickness of the substrate is preferably 0.5 μm or more and 50 μm or less, more preferably 1 μm or more and 20 μm or less, and still more preferably 1 μm or more and 10 μm or less. Thereby, for example, the balance between the mechanical strength and the transferability of the protective layer can be further improved.

<Protective layer>
The protective layer is a layer responsible for protecting the surface of the transfer-receiving material after being transferred from the thermal transfer sheet onto the transfer-receiving material. 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 to the substrate is referred to as the second surface. That is, the protective layer has a first surface and a second surface facing the first surface. In FIGS. 1 and 2, the reference number for the first surface is 26 and the reference number for the second surface is 28. FIG. In one embodiment, when the protective layer comprises a release layer and an adhesive layer, the release layer constitutes the first surface and the adhesive layer constitutes the second surface.

In the thermal transfer sheet of the present disclosure, the dynamic friction coefficient between the surface (second surface) of the protective layer opposite to the base material and the surface (first surface) of the protective layer facing the base material is 0.34 or more. It is characterized by being 0.85 or less. The coefficient of dynamic friction is preferably 0.34 or more and 0.60 or less. As a result, for example, when the protective layer is thermally transferred to the transferred material two or more times, it is possible to suppress the occurrence of wrinkles in the printed matter obtained.

In the present disclosure, the "dynamic friction coefficient" is measured in accordance with JIS K7125:1999 "Plastics-Films and Sheets-Friction Coefficient Test Method". The conditions for measuring the coefficient of dynamic friction are as follows: load on sliding piece: 1.96 N, contact area of sliding piece: 22 cm ² , test speed: 1000 mm/min.

The dynamic friction coefficient is measured as follows. First, the protective layer of the first area is transferred from the thermal transfer sheet onto the transfer receiving material. Next, the second surface of the protective layer in the second area of the thermal transfer sheet and the first surface of the protective layer in the first area transferred onto the transferred material are faced to each other, and under the above measurement conditions, Measure the dynamic friction coefficient.

Transfer conditions are described below. A protective layer is transferred to a polyvinyl chloride (PVC) card (standard white card, manufactured by Dai Nippon Printing Co., Ltd.) at an energy setting of ± 0 using the above thermal transfer sheet and a card printer SD360 (Enrast). .

(Release layer)
In one embodiment, the protective layer comprises a release layer as the layer closest to the substrate among the layers constituting the protective layer. By providing the release layer, the transferability of the protective layer can be further improved. The release layer is transferred as a part of the protective layer during thermal transfer, and after the final transfer of the protective layer, it becomes the surface layer of the thermally transferred image, and acts to improve the abrasion resistance of the thermally transferred image.

The release layer contains a binder in one embodiment.
Examples of binders include resin materials. Examples of resin materials include (meth)acrylic resin; styrene resin; vinyl resins such as polyvinyl alcohol, polyvinyl acetate, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl butyral, polyvinyl acetal and polyvinylpyrrolidone; polyethylene. polyesters such as terephthalate and polyethylene naphthalate; cellulose resins such as ethyl cellulose, hydroxyethyl cellulose, ethyl hydroxy cellulose, methyl cellulose and cellulose acetate; polyamides; polyurethanes; UV-absorbing resins, as well as ionizing radiation curable resins can be mentioned.

The release layer, in one embodiment, contains a (meth)acrylic resin. Examples of (meth)acrylic resins include (meth)acrylic acid polymers, (meth)acrylic acid ester polymers, copolymers of (meth)acrylic acid and other monomers, and (meth)acrylic acid Copolymers of esters and other monomers are included. Specific examples of (meth)acrylic resins include polymethyl (meth)acrylate, polyethyl (meth)acrylate, polypropyl (meth)acrylate, polybutyl (meth)acrylate, polyisobutyl (meth)acrylate, and ethyl (meth)acrylate. -methyl (meth)acrylate copolymer, butyl (meth)acrylate-methyl (meth)acrylate copolymer, ethylene-methyl (meth)acrylate copolymer and styrene-methyl (meth)acrylate copolymer.
The release layer can contain one or more (meth)acrylic resins.

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, still more preferably 15,000 or more and 100,000 or less, especially It is preferably 20,000 or more and 80,000 or less. In the present disclosure, Mw is measured by gel permeation chromatography (GPC) using polystyrene as a standard substance in accordance with JIS K7252-1.

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, still more preferably 50° C. or higher and 120° C. or lower. In the present disclosure, Tg is obtained by differential scanning calorimetry (DSC) according to JIS K7121.

The ionizing radiation curable resin includes, for example, a resin obtained by crosslinking and curing a radically polymerizable polymer or a radically polymerizable oligomer by irradiation with ionizing radiation. Specifically, a radically polymerizable polymer or a radically polymerizable oligomer If necessary, a photopolymerization initiator is added to the resin, and the resin is polymerized and crosslinked by electron beam or ultraviolet irradiation.

The release layer can contain one or more binders.
The binder content in the release layer is preferably 80% by mass or more, more preferably 85% by mass or more, relative to the total mass of the release layer. Thereby, for example, sufficient durability can be imparted to the release layer.

The release layer may contain a lubricant. As a result, for example, the coefficient of dynamic friction can be set to a lower value, and when the protective layer is transferred for the second time, for example, the thermal transfer sheet can be kept running well, and wrinkles are generated in the printed matter obtained. can be suppressed.

Lubricants include, for example, waxes; metal salts of higher fatty acids; organic particles such as (meth)acrylic resins, crosslinked polystyrene and fluororesins (e.g., polytetrafluoroethylene); silica, clay, talc, titanium oxide, calcium carbonate, and sulfuric acid. Inorganic particles such as barium are included.

Examples of waxes include synthetic waxes such as paraffin wax, microcrystalline wax, silicone wax, oxidized wax, ozokerite, ceresin, polyester wax and polyethylene wax; beeswax, spermaceti, Japan wax, rice bran wax, carnauba wax, candelilla wax and Natural waxes such as 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; fatty acid esters of sorbitan, etc. and higher fatty acid amides such as stearic acid amide and oleic acid amide. Metal salts of higher fatty acids include, for example, zinc stearate, zinc stearyl phosphate, calcium stearate and magnesium stearate.

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. Thereby, for example, the dynamic friction coefficient can be set lower. The average particle size of the lubricant means the volume average particle size and is measured according to JIS Z8819-2:2019.

The release layer can contain one or more lubricants.
The content of the lubricant in the release layer may be, for example, 1% by mass or more and 20% by mass or less, or 2% by mass or more and 15% by mass or less, relative to the total mass of the release layer. Thereby, transparency can be ensured, for example, exhibiting the effect by a lubricating agent.

The release layer may contain additives. Additives include, for example, benzophenone UV absorbers, benzotriazole UV absorbers, benzoate UV absorbers, triazine UV absorbers, UV absorbers such as titanium oxide and zinc oxide; hindered amine light stabilizers and Ni Light stabilizers such as chelate light stabilizers; antioxidants such as hindered phenol antioxidants, sulfur antioxidants, phosphorus antioxidants and lactone antioxidants.

The release layer can 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 with respect to the total mass of the release layer.

The thickness of the release layer is preferably 0.1 μm or more and 20 μm or less, more preferably 0.3 μm or more and 10 μm or less, and still more preferably 0.5 μm or more and 3 μm or less. As a result, for example, it is possible to suppress the occurrence of defective transfer of the protective layer, and to impart a sufficient protective function to the transfer-receiving body.

For the release layer, for example, a coating liquid containing the above materials is applied to the substrate or release layer by known means such as roll coating, reverse roll coating, gravure coating, reverse gravure coating, bar coating and rod coating. It can be formed by drying.

(adhesive layer)
The protective layer, in one embodiment, comprises an adhesive layer provided on the surface of the release layer opposite to the substrate. The adhesive layer is a layer that improves the adhesion between the protective layer and the material to be transferred. The adhesive layer can be formed by, for example, a conventionally known pressure-sensitive adhesive or heat-sensitive adhesive.

The adhesive layer contains a resin material in one embodiment.
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, Various resins modified with polyester, polyurethane, cellulose resin, silicone resin and fluororesin, and silicone or fluorine can be used. Among these, vinyl chloride-vinyl acetate copolymers, polyesters and (meth)acrylic resins are more preferred, and vinyl chloride-vinyl acetate copolymers and polyesters are more preferred.

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 still more preferably 55° C. or higher and 75° C. or lower. As a result, for example, printing performance can be further improved.

Vinyl chloride-vinyl acetate copolymer means a copolymer having structural units derived from vinyl chloride and structural units derived from vinyl acetate. It may have a structural unit derived from a compound.

The content of structural units derived from vinyl chloride in the vinyl chloride-vinyl acetate copolymer may be, for example, 10% by mass or more and 90% by mass or less, 30% by mass or more and 90% by mass or less, or 50% by mass or more and 90% by mass. % by mass or less. The content of structural units derived from vinyl acetate in the vinyl chloride-vinyl acetate copolymer may be, for example, 10% by mass or more and 90% by mass or less, 10% by mass or more and 70% by mass or less, or 10% by mass or more and 50% by mass. % by mass or less.

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.

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.

Polyester means a copolymer of a dicarboxylic acid compound and a diol compound.
Dicarboxylic acid compounds include, for example, malonic acid, succinic acid, glutaric acid, adipic acid, suberic acid, sebacic acid, dodecanedioic acid, eicosandioic acid, pimelic acid, azelaic acid, methylmalonic acid and ethylmalonic acid, adamantane dicarboxylic acid, norbornene dicarboxylic acid, cyclohexanedicarboxylic acid, decalinedicarboxylic 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, phenanthenedicarboxylic acid, 9,9'-bis (4-Carboxyphenyl)fluoric acid and their ester derivatives.

Examples of diol compounds include ethylene glycol, 1,2-propanediol, 1,3-propanediol, butanediol, 2-methyl-1,3-propanediol, hexanediol, neopentyl glycol, cyclohexanedimethanol, and cyclohexane. diethanol, 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-hydroxy cyclohexylpropane), 2,2-bis(4-(2-hydroxyethoxy)cyclohexyl)propane, cyclopentanediol, 3-methyl-1,2-cyclopentadiol, 4-cyclopentene-1,3-diol, adamandiol , paraxylene glycol, bisphenol A, bisphenol S, styrene glycol, trimethylolpropane and pentaerythritol.

The polyester may contain structural units derived from polymerizable compounds other than the dicarboxylic acid compound and the 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.

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 according to JIS K7252-1 by gel permeation chromatography (GPC) using polystyrene as a standard substance.

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

The adhesive layer may contain a lubricant. As a result, for example, the coefficient of dynamic friction can be set to a lower value, and when the protective layer is transferred for the second time, for example, the thermal transfer sheet can be kept running well, and wrinkles are generated in the printed matter obtained. can be suppressed.
The details of the lubricant are as described above, and the description thereof is omitted here.

The adhesive layer can contain one or more lubricants.
The content of the lubricant in the adhesive layer may be, for example, 1% by mass or more and 20% by mass or less, or 2% by mass or more and 15% by mass or less, relative to the total mass of the adhesive layer. Thereby, transparency can be ensured, for example, exhibiting the effect by a lubricating agent.

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

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.

For the adhesive layer, for example, a coating liquid containing the above materials is applied to the release layer by known means such as roll coating, reverse roll coating, gravure coating, reverse gravure coating, bar coating and rod coating, and dried. can be formed by

<Release layer>
A thermal transfer sheet of the present disclosure, in one embodiment, comprises a release layer positioned between the substrate and the protective layer. The release layer is a layer provided as desired so that the protective layer can be easily peeled off from the substrate during thermal transfer, and is a layer that stays on the substrate side during thermal transfer.

The release layer contains a binder and a release agent in one embodiment.
Examples of binders include resins such as (meth)acrylic resins, vinyl resins, polyurethanes, polyamides, polyimides, melamine resins, polyol resins, silicone resins, silicone-modified (meth)acrylic resins, fluorine resins, fluorine-modified resins and cellulose resins. materials.
The release layer can contain one or more binders.

Examples of release agents include metal soaps such as zinc stearate, zinc stearyl phosphate, calcium stearate and magnesium stearate, silicone oils, fluorine compounds, phosphate esters, fatty acid amides, polyethylene wax, carnauba wax and paraffin wax. waxes.
The release layer can contain one or more release agents.

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

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. Thereby, for example, the transferability of the protective layer in the thermal transfer sheet can be improved.

For the release layer, for example, a coating liquid containing the above materials is applied to the substrate by known means such as roll coating, reverse roll coating, gravure coating, reverse gravure coating, bar coating and rod coating, and dried. can be formed by

<Color material layer>
The thermal transfer sheet of the present disclosure comprises a protective layer and at least one colorant layer on one side of a substrate in a face-sequential manner. That is, in the thermal transfer sheet of the present disclosure, the coloring material layer and the protective layer are provided on one surface of the substrate in a frame-sequential manner. The coloring material layer and the protective layer are provided, for example, in the longitudinal direction of the substrate in a plane-sequential manner. By providing a coloring material layer and a protective layer on a base material, for example, using the same thermal transfer sheet, a thermal transfer image can be formed on a transfer material and a protective layer can be transferred onto the formed thermal transfer image. It can be performed.

In the thermal transfer sheet 1 of the embodiment shown in FIG. 1, a single coloring material layer 30 is provided on one surface of the base material 10 . A plurality of coloring material layers, for example, a yellow layer, a magenta layer, a cyan layer, and optionally a black layer may be provided on one surface of the base material, for example, in the longitudinal direction of the base material. In the thermal transfer sheet 1 of the embodiment shown in FIG. 7, a yellow layer (Y), a magenta layer (M), a cyan layer (C) and a black layer (BK) are sequentially provided.

The thermal transfer sheet of the present disclosure may repeat one unit described above on one side of the substrate, that is, may have a plurality of units, for example, in the longitudinal direction of the substrate. One unit may include a single coloring material layer or a plurality of coloring material layers. When one unit includes a plurality of colorant layers, that is, when it is a colorant layer group, the respective colorant layers are provided in a frame-sequential manner. One unit, in one embodiment, consists of 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)). One unit, in one embodiment, consists of 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 (eg, 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 color material layer.

The coloring material layer may be, for example, a sublimation transfer type coloring material layer in which a sublimation dye is dissolved or dispersed in a binder, or a melt transfer type coloring material in which coloring materials such as pigments and dyes are dispersed in a hot-melt binder. It can be layers. The thermal transfer sheet may include both a sublimation transfer colorant layer and a melt transfer colorant layer. For example, yellow, magenta, and cyan colorant layers are used as sublimation transfer colorant layers, and a black colorant layer is used. may be used as a melt-transfer type coloring material layer, and these coloring material layers may be provided in a frame-sequential manner on the substrate. For example, the gradation image portion may be formed by the sublimation transfer type recording method, and the character portion may be formed by the melt transfer type recording method.

The coloring material layer contains a binder and a coloring material in one embodiment.
Examples of binders include resin materials such as polyesters, polyurethanes, polyamides, polyimides, polycarbonates, polyolefins, (meth)acrylic resins, vinyl resins, styrene resins, cellulose resins, phenoxy resins and ionomer resins. As the binder in the melt transfer type color material layer, in addition to the above resin materials, microcrystalline wax, carnauba wax, paraffin wax, Fischer-Tropsch wax, polyethylene wax, wood wax, beeswax, whale wax, ivory wax, wool wax, shellac wax, Waxes such as candelilla wax, petrolactam, polyester waxes, partially modified waxes, fatty acid esters and fatty acid amides may also be used. The melt transfer type colorant layer may contain both a resin material and a wax.
The coloring material layer can contain one or more binders.

The colorant may be a pigment such as an organic pigment or an inorganic pigment, or may be a dye. The dye may be a sublimable dye. Specific examples of colorants include carbon black, acetylene black, lamp black, black smoke, iron black, aniline black, silica, calcium carbonate, titanium oxide, cadmium red, cadmopon red, chrome red, vermillion, red iron oxide, and azo. pigments, alizarin lake, quinacridone, cochinyl lake perylene, yellow ocher, aureolin, cadmium yellow, cadmium orange, chrome yellow, zinc yellow, naples yellow, nickel yellow, greenish yellow, ultramarine, rock ultramarine, cobalt, phthalocyanine, Anthraquinone, indicoid, cinnabar green, cadmium green, chrome green, phthalocyanine, azomethine, perylene, aluminum pigments; and diarylmethane dyes, triarylmethane dyes, thiazole dyes, merocyanine dyes, pyrazolone dyes, methine dyes, indoaniline dyes, acetophenone Sublimation dyes such as azomethine dyes, pyrazoloazomethine dyes, xanthene dyes, oxazine dyes, thiazine dyes, azine dyes, acridine dyes, azo dyes, spiropyran dyes, indolinospiropyran dyes, fluorane dyes, naphthoquinone dyes, anthraquinone dyes and quinophthalone dyes is mentioned. Colorant hues include, for example, magenta, yellow, cyan, and black.
The colorant layer can contain one or more colorants.

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

In one embodiment, the colorant layer is a sublimation transfer type colorant layer.
The binder content in the sublimation transfer color material layer may be, for example, 20% by mass or more and 95% by mass or less, or 30% by mass or more and 90% by mass or less. The content of the sublimation dye in the sublimation transfer colorant layer may be, for example, 5% by mass or more and 80% by mass or less, or 10% by mass or more and 70% by mass or less. As a result, for example, print density and storability can be improved.

The sublimation transfer type colorant layer may be cured with a curing agent. Curing agents include, for example, epoxy resins, isocyanates and carbodiimides. One or more curing agents can be used.

A dye primer layer may be provided between the substrate and the sublimation transfer type color material layer.

The colorant layer, in one embodiment, is a melt transfer colorant layer.
The content of the binder in the melt transfer colorant layer may be, for example, 20% by mass or more and 90% by mass or less, or may be 30% by mass or more and 80% by mass or less. The content of the colorant in the melt transfer colorant layer may be, for example, 10% by mass or more and 60% by mass or less, or may be 20% by mass or more and 50% by mass or less.

A release layer may be provided between the substrate and the melt transfer type color material layer.

The thickness of the coloring material 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 still more preferably 0.1 μm or more and 5 μm or less.

The coloring material layer is formed by, for example, applying a coating liquid containing the above materials to a substrate by known means such as roll coating, reverse roll coating, gravure coating, reverse gravure coating, bar coating and rod coating, followed by drying. can be formed by

<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 provided with the protective layer. As a result, for example, the occurrence of sticking and wrinkles during thermal transfer can be suppressed.

The back layer, in one embodiment, contains a resin material. Examples of resin materials include polyolefins, styrene resins, vinyl resins, polyesters, polyurethanes, polyethers, polyamides, polyimides, polyamideimides, polycarbonates, cellulose resins, and silicone modified products thereof.
The back layer can contain one or more resin materials.

In one embodiment, the back layer contains a cured resin obtained by curing a hydroxyl-containing resin with an isocyanate curing agent. As a result, for example, the occurrence of sticking and wrinkles during thermal transfer can be suppressed.

Hydroxyl group-containing resins include, for example, polyvinyl alcohol, polyvinyl butyral, polyvinyl acetal and (meth)acrylic polyol. The content ratio of the hydroxyl group-containing structural units in the hydroxyl group-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. As a result, for example, the heat resistance of the back layer can be improved, and the heat energy transmitted to the substrate and the protective layer can be reduced, so that the printability can be further improved. "Hydroxy group-containing structural unit" means the ratio of monomer structural units having hydroxyl groups in the resin, and is a value calculated as the ratio (% by mass) of the monomer structural units having hydroxyl groups with respect to the mass of the entire resin.
One or more hydroxyl group-containing resins can be used.

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, and xylylene diisocyanate. , triphenylmethane triisocyanate and tris(isocyanatophenyl)thiophosphate.
One or two or more isocyanate curing agents can be used.

The molar equivalent ratio (--NCO/--OH) between the isocyanate group (--NCO) possessed by the isocyanate curing agent and the hydroxyl group (--OH) possessed by the hydroxyl group-containing resin is preferably 1.5 or more. As a result, for example, the heat resistance of the back layer can be improved, and the heat energy transmitted to the substrate and the protective layer can be reduced, so that the printability can be further improved.

The content of the cured resin in the back layer is preferably 50% by mass or more and 90% by mass or less, more preferably 55% by mass or more and 80% by mass or less. Thereby, for example, printability can be further improved.

For the purpose of improving slipperiness, etc., the back layer contains 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. Release agents such as waxes and paraffin waxes; additives such as organic particles such as fluororesins, inorganic particles such as silica, clay, talc and calcium carbonate, and organic and inorganic particles such as silicone resins. .

The content of the additive in the back layer is preferably 10% by mass or more and 50% by mass or less, more preferably 20% by mass or more and 45% by mass or less. Thereby, slip property can be improved more, for example.

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, from the viewpoint of improving heat resistance, slip resistance, and the like.

For the back layer, for example, a coating liquid containing the above materials is applied to the substrate by known means such as roll coating, reverse roll coating, gravure coating, reverse gravure coating, bar coating and rod coating, and dried. can be formed by

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

In the present disclosure, two or more protective layers can be laminated on the image by transferring the protective layer two or more times. According to the manufacturing method of the present disclosure, a printed material having an image composed of characters, line drawings, patterns, symbols, combinations thereof, etc., and two or more protective layers provided on the image can be obtained (see FIG. 3 and FIG. 4).

<Preparation process>
In the preparation step, a thermal transfer sheet and a material to be transferred are prepared.
A thermal transfer sheet includes a base material, at least one coloring material layer, and a transferable protective layer. The coloring material layer and the protective layer are provided on one surface of the substrate in a frame-sequential manner. 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 sequential order.

Regarding the thermal transfer sheet used in the method for producing a printed matter of the present disclosure, the configuration (for example, the layer configuration, the composition and thickness of each layer) other than the requirements related to the coefficient of dynamic friction are as described above, so the description is omitted 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.

The material to be transferred includes, for example, the above resin film, glass substrate, metal substrate, ceramic substrate, cloth substrate, paper substrate, and laminated substrates thereof. The material to be transferred may be a card substrate mainly composed of polyvinyl chloride, vinyl chloride-vinyl acetate copolymer or polycarbonate. Examples of cloth substrates include synthetic fibers such as nylon fibers, polyester fibers, rayon fibers, acetate fibers, acrylic fibers, vinylon fibers, polypropylene fibers and polyvinylidene chloride fibers; natural fibers such as cotton, silk, hemp and wool. and a substrate formed from fibers of Examples of paper substrates include woodfree paper, plain paper, art paper, coated paper, resin-coated paper, cast-coated paper, paperboard, synthetic paper, and impregnated paper. The material to be transferred may be, for example, a thermal transfer image-receiving sheet comprising a substrate and a receiving layer provided on one surface of the substrate. The material to be transferred may have an image, may be colored, or may have transparency.

<Image forming process>
In the image forming step, an image is formed on a transfer-receiving material using the coloring material layer included in the thermal transfer sheet. For example, the colorant layer of the thermal transfer sheet is brought into contact with the surface of the material to be transferred, and then heat is applied to a desired region of the thermal transfer sheet to form an image on the material to be transferred.

For example, the 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 superimposing a thermal transfer sheet and an object to be transferred, passing the thermal transfer sheet between a thermal head and a platen roll provided in a thermal transfer printer, and heating the thermal transfer sheet using the thermal head. . A thermal transfer recording method for forming an image on a transfer material may be a sublimation transfer type, a melt transfer type, or a combination thereof. By combining the sublimation transfer type and the melt transfer type, for example, the gradation image portion may be formed by the sublimation transfer type recording method and the character portion may be formed by the melt transfer type recording method. Thermal transfer recording is applicable not only to the thermal head system, but also to thermal transfer means that heats by laser irradiation.

<Primary transfer process>
In the primary transfer step, at least a portion of the protective layer in the first region provided on the thermal transfer sheet is transferred so as to cover at least the image formed on the transfer target.

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, a thermal transfer sheet and an image-formed object are superimposed, passed between a thermal head and a platen roll provided in a thermal transfer printer, and the thermal transfer sheet is heated using the thermal head. , the protective layer is transferred so as to cover the image formed on the transferred material. Transfer of the protective layer may be performed using a heat roll method. The protective layer may be transferred by sandwiching the thermal transfer sheet and the image-receiving material between a heated flat plate and a flat plate, respectively, or by sandwiching between a heated flat plate and a roll and hot-pressing them.

When a thermal head is used as a means for thermally transferring 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, the thermal transfer means for image formation and the thermal transfer means for the protective layer are preferably performed in-line using a single thermal transfer printer. When stacking the above layers, it is preferable to stack the protective layers inline.

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

In the method for producing a print according to the present disclosure, 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. It is characterized by being 0.85 or less. The coefficient of dynamic friction is preferably 0.34 or more and 0.60 or less. As a result, for example, when the protective layer is thermally transferred to the transferred material two or more times, it is possible to suppress the occurrence of wrinkles in the printed matter obtained.

For example, by using the thermal transfer sheet of the present disclosure described above as the thermal transfer sheet, the coefficient of dynamic friction within the above range can be achieved. 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 unevenness on the surface of the protective layer transferred onto the transferred body. .

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 on one surface of the substrate in a frame-sequential manner. The length of the protective layer is at least twice the screen length of the colorant layer, and the dynamic friction coefficient between the surface of the protective layer opposite to the base material and the surface of the protective layer facing the base material is A thermal transfer sheet, which is 0.34 or more and 0.85 or less.
[2] The thermal transfer sheet of [1] above, wherein the transferable protective layer comprises a release layer and an adhesive layer from the substrate side.
[3] The thermal transfer sheet of [2] above, wherein the release layer contains a (meth)acrylic resin.
[4] The thermal transfer sheet of [2] or [3] above, wherein the release layer contains a lubricant.
[5] The thermal transfer sheet according to any one of [2] to [4] above, 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 [2] to [5] above, wherein the adhesive layer contains a lubricant.
[7] The coloring material 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 sequentially provided, and the protective layer has a length equal to the yellow layer. The thermal transfer sheet according to any one of [1] to [6] above, wherein the screen length of each of the magenta layer and the cyan layer is twice or more.
[8] The above [ 1] The thermal transfer sheet according to any one of [6].
[9] A method for producing a printed matter, comprising a step of preparing a thermal transfer sheet and a transfer-receiving material, an image forming step, a primary transfer step, and a secondary transfer step, wherein the thermal transfer sheet comprises a substrate and at least One colorant layer and a transferable protective layer are provided, the colorant layer and the protective layer are provided on one surface of the base material in sequence, and the length of the protective layer is equal to the length of the colorant layer. is at least twice the screen length, the protective layer has at least the first region and the second region in frame sequence, and the image forming process is performed by the coloring material layer included in the thermal transfer sheet. The primary transfer step is a step of transferring at least a part of the protective layer in the first region of the thermal transfer sheet so as to cover at least the image formed on the transferred material. and the secondary transfer step is a step of transferring at least part of the protective layer in the second region of the thermal transfer sheet onto the protective layer transferred onto the image, and and a surface of the protective layer in the second region of the thermal transfer sheet, wherein the coefficient of dynamic friction is 0.34 or more and 0.85 or less.

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 the Examples. In the description below, "parts by mass" is simply referred to as "parts." The amount of components contained in the coating liquid described below is the amount of solid content.

[Example 1]
A PET film (Lumirror (registered trademark) #5A-F53, Toray Industries, Inc.) having a thickness of 5 μm or less was prepared as a substrate. The back layer coating solution described below was applied to one surface of a PET film and dried at 100° C. for 2 minutes to form a back layer having a thickness of 1.2 μm. The following coating solution for yellow dye layer, the following coating solution for magenta dye layer, and the following coating solution for cyan dye layer were applied in sequence onto the surface of the PET film opposite to the surface on which the back layer was provided. and dried at 80° C. for 1 minute to sequentially form a 1 μm thick yellow dye layer, a 1 μm thick magenta dye layer, and a 1 μm thick cyan dye layer on the PET film. Further, the following release layer coating solution was applied onto the PET film so as to be face-sequential with respect to the dye layers, and dried at 100° C. for 1 minute to form a release layer having a thickness of 1 μm. The adhesive layer coating liquid described below was applied to the release layer and dried at 100° C. for 1 minute to form an adhesive layer having a thickness of 1.5 μm. The protective layer is 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.
A thermal transfer sheet was obtained as described above.

<Coating solution 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 (Barnock (registered trademark) D750, DIC Corporation)
・ Silicone resin fine particles (average particle size = 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.)
- Polyethylene wax 3 parts (Polywax 3000, Toyo Adol Co., Ltd.)
・Ethoxylated alcohol-denatured wax 7 parts (Unitox 750, Toyo Adol Co., Ltd.)
・200 parts of methyl ethyl ketone (MEK) ・100 parts of toluene

<Coating solution for yellow dye layer>
・ Solvent Yellow 93 6 parts ・ Polyvinyl acetal 5 parts (manufactured by Sekisui Chemical Co., Ltd., trade name: S-Lec (registered trademark) KS-5)
・50 parts of MEK ・50 parts of toluene

<Coating solution for magenta dye layer>
Disperse Red 60 3 parts Disperse Violet 26 4 parts Polyvinyl acetal 5 parts (manufactured by Sekisui Chemical Co., Ltd., trade name: S-Lec (registered trademark) KS-5)
・50 parts of MEK ・50 parts of toluene

<Coating solution for cyan dye layer>
・ Solvent Blue 63 4 parts ・ Disperse Blue 354 4 parts ・ Polyvinyl acetal 5 parts (manufactured by Sekisui Chemical Co., Ltd., trade name: S-Lec (registered trademark) KS-5)
・50 parts of MEK ・50 parts of toluene

<Coating solution for release layer>
・ (Meth) acrylic resin A 20 parts (0403KA, Taisei Fine Chemical Co., Ltd.,
Tg: 105°C, Mw: 73,000)
・40 parts of MEK ・40 parts of toluene

<Coating solution for adhesive layer>
Vinyl chloride-vinyl acetate copolymer 20 parts (VINNOL (registered trademark) H14/36, Wacker Chemie AG,
Vinyl chloride content: 86% by mass, vinyl acetate content: 14% by mass,
Tg: 69°C, Mw: 30,000 to 40,000)
・40 parts of MEK ・40 parts of toluene

[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 those shown in Table 1.

Components used in Examples and Comparative Examples are described below.
・ (Meth) acrylic resin B: KV-4941, Shin-Nakamura Chemical Co., Ltd.
Tg: 61°C, Mw: 33,000
・ Saturated copolyester: UE-3380, Unitika Ltd.,
Tg: 60°C
Polyethylene wax: POLYWAX® 655,
Baker Hughes, Melting point: 99°C
- Silica particles: NIPGEL (registered trademark) AZ-400, Tosoh Silica Co., Ltd.,
Average secondary particle size: 3.0 μm
・Silicone oil: KF-96, Shin-Etsu Chemical Co., Ltd.

[Method for evaluating print wrinkles]
Using a PVC card (standard white card, manufactured by Dai Nippon Printing Co., Ltd.), the thermal transfer sheet obtained in Examples and Comparative Examples, and a card printer SD360 (Enrast), energy setting ± 0, the first time A protective layer transfer was performed. 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 print wrinkles was visually confirmed.
AA: Visually confirmed, the PVC card after transfer of the protective layer had no print wrinkles.
BB: Visually confirmed, printed wrinkles were found on the PVC card after transfer of the protective layer.

[Dynamic friction coefficient]
In accordance with JIS K7125: 1999 "Plastics - Film and sheet - Friction coefficient test method", the surface of the protective layer in the thermal transfer sheet (second surface of the protective layer), and the protective layer was transferred to the PVC card for the first time. The dynamic friction coefficient between the surface of the protective layer (the first surface of the protective layer) and the printed matter obtained was measured. The conditions for measuring the coefficient of dynamic friction were as follows: load of sliding piece: 1.96 N, contact area of sliding piece: 22 cm ² , test speed: 1000 mm/min.

REFERENCE SIGNS LIST 1 Thermal transfer sheet 2 Printed matter 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 Transferable protective layer 28 Second surface of transferable protective layer 30 Color material layer 40 Back layer 50 Transferee

Claims (9)

A thermal transfer sheet comprising a substrate, at least one coloring material layer, and a transferable protective layer,
The coloring material layer and the protective layer are provided on one surface of the base material in a frame-sequential manner,
The length of the protective layer is at least twice the screen length of the colorant layer,
The coefficient of dynamic friction between the surface of the protective layer opposite to the base material and the surface of the protective layer facing the base material is 0.34 or more and 0.85 or less.
Thermal transfer sheet. 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, wherein the release layer contains a lubricant. The thermal transfer sheet according to any one of claims 2 to 4, wherein the adhesive layer contains at least one selected from vinyl chloride-vinyl acetate copolymer and polyester. The thermal transfer sheet according to any one of Claims 2 to 5, wherein the adhesive layer contains a lubricant. The coloring material 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 sequentially provided, and the length of the protective layer is 7. The thermal transfer sheet according to any one of claims 1 to 6, wherein the screen length of each of the yellow layer, the magenta layer and the cyan layer is twice or more. The color material layer has at least a black layer, the black layer and the protective layer are provided in a frame-sequential manner, and the length of the protective layer is at least twice the screen length of the black layer. The thermal transfer sheet according to any one of claims 1-6. a step of preparing a thermal transfer sheet and an object to be transferred;
an image forming process;
a primary transfer step;
A method for producing a printed matter, comprising a secondary transfer step,
The thermal transfer sheet comprises a substrate, at least one colorant layer, and a transferable protective layer, and the colorant layer and the protective layer are provided on one surface of the substrate in a frame-sequential manner. 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-sequential order,
wherein the image forming step is a step of forming an image on the transferred material using the coloring material layer included in the thermal transfer sheet;
wherein the primary transfer step is a step of transferring at least part of a protective layer in a first region of the thermal transfer sheet so as to cover at least the image formed on the transfer target;
The secondary transfer step is a step of transferring at least a part of a protective layer in a second region included in the thermal transfer sheet onto the protective layer transferred onto the image, and the image is transferred in the primary transfer step. The coefficient of dynamic friction between the surface of the protective layer transferred thereon 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.
A method for producing prints.

Images