JP6930346B2 - Thermal transfer sheet and method for manufacturing photographic paper using it - Google Patents

Description

The present invention includes a thermal transfer sheet, more specifically, a substrate and a transfer layer, and the transfer layer includes a receiving layer and a foamed layer in this order, and a thermal transfer sheet using the same. Regarding the manufacturing method.

Images are widely used by the sublimation thermal transfer method because they have excellent transparency, high reproducibility of neutral colors and high gradation, and can easily form high-quality images equivalent to conventional full-color photographic images. It has been.

In the sublimation type thermal transfer method, for example, a sheet provided with a dye layer and a transferred body are superposed, and heat is applied to the sheet provided with the dye layer to transfer the sublimable dye contained in the dye layer to the transferred body. It is a method of forming an image and obtaining a printed matter.

The transferred material used in the sublimation type thermal transfer method is required to have dye dyeing property, but plain paper or the like has poor dyeing property, so that a receiving layer having high dyeing property is provided. The receiving layer is transferred to the surface of the transferred body using the provided thermal transfer sheet (Patent Document 1).

By the way, in recent years, a wide variety of designs are required for photographic papers. For example, in Patent Document 2, a photographic paper having a layer containing a fluorescent agent is formed, and in Patent Document 3, an image having a high metallic luster is formed. The printed material has been proposed.

Japanese Unexamined Patent Publication No. 9-241055 Japanese Unexamined Patent Publication No. 2003-025736 Japanese Unexamined Patent Publication No. 2004-291400

Nowadays, the present inventors have described a heat transfer sheet including a base material and a receiving layer and a foaming layer as a transfer layer, wherein the foaming layer contains foamed particles having a specific foaming temperature, according to the heat transfer sheet. We have obtained the finding that it is possible to produce highly-designed printed matter with a textured surface.
Further, according to the thermal transfer sheet, the foamed particles contained in the foamed layer do not foam due to the heating during the thermal transfer of the transfer layer onto the transfer material and the image formation on the receiving layer, so that the dye on the receiving layer is dyed. It was found that it is possible to maintain the dyeability of the particles and prevent the occurrence of scratches and cracks.

Therefore, an object of the present invention is to provide a thermal transfer sheet capable of producing a printed matter having an uneven surface, having a high design property, and having a good image formed without blurring or cracking. Is.

The thermal transfer sheet according to the present invention includes a base material and a transfer layer, the transfer layer includes a receiving layer and a foamed layer in this order, and the foamed layer has foamed particles having a foaming temperature of 140 ° C. or higher and 200 ° C. or lower. It is characterized by including.

In one embodiment, the volume average particle diameter of the foamed particles contained in the foamed layer included in the thermal transfer sheet is 10 μm or more and 50 μm or less.

In one embodiment, the content of the foamed particles in the foamed layer included in the thermal transfer sheet is 30% by mass or more and 80% by mass or less.

In one embodiment, the receiving layer included in the thermal transfer sheet contains a vinyl chloride-vinyl acetate copolymer.

In one embodiment, the thickness of the receiving layer included in the thermal transfer sheet is 1 μm or more and 5 μm or less.

In one embodiment, the thermal transfer sheet further comprises an adhesive layer on the foam layer.

In one embodiment, the foam layer included in the thermal transfer sheet is an aqueous coating film.

In one embodiment, the thermal transfer sheet further comprises a dye layer so that it is surface-sequential with the transfer layer.

The method for producing a printed matter according to the present invention is to superimpose the thermal transfer sheet and the transferred body and heat the thermal transfer sheet from a surface opposite to the surface on which the transfer layer is provided on the thermal transfer sheet. Includes a step of transferring the transfer layer onto the body, a step of forming an image on the receiving layer provided in the transfer layer, and a step of heating the transferred body to foam the foamed particles contained in the foamed layer. It is characterized by.

In one embodiment, the heating temperature in the transfer step of the method for producing a printed matter is less than 140 ° C.

In one embodiment, the heating temperature in the foaming step of the method for producing a printed matter is 140 ° C. or higher and 250 ° C. or lower.

According to the thermal transfer sheet of the present invention, it is possible to provide a thermal transfer sheet capable of producing a printed matter having an uneven surface, having a high design property, and forming a good image without blurring or cracking. ..

It is schematic cross-sectional view which shows one Embodiment of the thermal transfer sheet of this invention. It is schematic cross-sectional view which shows one Embodiment of the thermal transfer sheet of this invention. It is schematic cross-sectional view which shows one Embodiment of the thermal transfer sheet of this invention.

(Thermal transfer sheet)
As shown in FIG. 1, the thermal transfer sheet 10 according to the present invention includes a base material 11 and a transfer layer 12, and the transfer layer 12 includes a receiving layer 13 and a foamed layer 14 in this order.
Further, in one embodiment, the transfer layer 12 includes an adhesive layer 15 on the foam layer 14 as shown in FIG.
Further, in one embodiment, the thermal transfer sheet 10 according to the present invention includes dye layers 16, 17 and 18 so as to be surface-sequential to the transfer layer 12 as shown in FIG.
Further, in one embodiment, as shown in FIG. 3, the thermal transfer sheet 10 according to the present invention includes a primer layer 19 between the base material 11 and the dye layers 16, 17, and 18.
Further, in one embodiment, the thermal transfer sheet 10 according to the present invention has a transfer layer 12 as shown in FIG.
The colored layer 20 is provided so as to be surface-sequential with the dye layers 16, 17, and 18 and / or the dye layers 16, 17, and 18.
Further, in one embodiment, as shown in FIG. 3, the thermal transfer sheet 10 according to the present invention includes a release layer 21 between the base material 11 and the colored layer 20.
Further, in one embodiment, the thermal transfer sheet 10 according to the present invention includes a back surface layer 22 on a surface opposite to the surface of the base material 11 on which the transfer layer 12 is provided, as shown in FIGS.

Hereinafter, each layer included in the thermal transfer sheet according to the present invention will be described.

(Base material)
The base material has heat resistance that can withstand the heat energy applied during thermal transfer (for example, heat from a thermal head), and has mechanical strength and solvent resistance that can support a receiving layer or the like provided on the base material. If there is, it can be used without any particular restrictions.

As the base material, for example, polyesters such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), polyethylene terephthalate-isophthalate copolymer and terephthalic acid-cyclohexanedimethanol-ethylene glycol copolymer. Based resin, polyamide resin such as nylon 6 and nylon 6,6, polyolefin resin such as polyethylene (PE), polypropylene (PP) and polymethylpentene, polyvinyl chloride, polyvinyl alcohol (PVA), polyvinyl acetate, chloride Vinyl-vinyl acetate copolymer, vinyl resin such as polyvinyl butyral and polyvinylpyrrolidone (PVP), (meth) acrylic resin such as polyacrylate, polymethacrylate and polymethylmethacrylate, polyimide such as polyimide and polyetherimide A film composed of a resin, a styrene resin, and a cellulose resin such as cellophane, cellulose acetate, nitrocellulose, cellulose acetate propionate (CAP), and cellulose acetate butyrate (CAB) (hereinafter, simply "resin film"). ".) Can be used.
Among the above-mentioned resins, polyester resins such as PET and PEN are preferable, and PET is particularly preferable, from the viewpoint of heat resistance and mechanical strength.
In the present invention, "(meth) acrylic" means to include both "acrylic" and "methacryl".

Further, the above-mentioned laminated body of the resin film can also be used as a base material.
The laminate of the resin film can be produced by using a dry lamination method, a wet lamination method, an extraction method, or the like.

When the base material is a resin film, the resin film may be a stretched film or an unstretched film, but from the viewpoint of strength, a stretched film stretched in the uniaxial direction or the biaxial direction is used. It is preferable to use it.

Further, from the viewpoint of improving the adhesion to the receiving layer, the back surface layer and the like and improving the blocking resistance, the base material preferably has irregularities on its surface.
Examples of the means for forming irregularities on the surface of the base material include mat material kneading processing, sandblasting processing, hairline processing, mat coating processing, and chemical etching processing. The mat material kneading process is a processing method for forming a base material from a resin in which an inorganic substance or an organic substance is kneaded. The matte coating process is a processing method in which a coating material containing an organic substance or an inorganic substance is coated on the surface of the base material to give unevenness to the surface of the base material.

The thickness of the base material is preferably 2 μm or more and 12 μm or less, and more preferably 3 μm or more and 6 μm or less. By setting the thickness of the base material within the above numerical range, the mechanical strength of the base material and the transfer of heat energy during thermal transfer can be improved.

(Transfer layer)
The transfer layer included in the thermal transfer sheet of the present invention is a layer that transfers onto the transferred body by heating the thermal transfer sheet, and includes at least a receiving layer and a foamed layer as described above. Further, an adhesive layer may be provided on the foam layer.

(Receptive layer)
As a material for forming the receiving layer, a conventionally known resin material that easily accepts the heat transfer dye of the sublimating dye can be used. For example, a polyester resin, a polyamide resin, a polyolefin resin, or (meth) acrylic can be used. Examples thereof include based resins, vinyl resins, polyimide resins, and cellulose resins.
Among these, vinyl-based resins are preferable, and vinyl chloride-vinyl acetate copolymers are particularly preferable, because they do not interfere with the foaming of the foamed particles contained in the foamed layer and can impart a better unevenness.
Further, the receiving layer preferably has a function as a peeling layer, that is, a function of adjusting the peeling force between the foamed layer and the base material, and from this point, a vinyl chloride-vinyl acetate copolymer is used. It is preferable to do so.
The receiving layer may contain two or more of the above resin materials.

The content of the resin material in the receiving layer is preferably 80% by mass or more and 98% by mass or less, and more preferably 90% by mass or more and 95% by mass or less.

The receiving layer may contain various additives as long as the characteristics of the present invention are not impaired. , Weatherproof material, antistatic material, thread friction reducing material, slip material, mold release material, antioxidant material, ion exchange material, dispersant material, ultraviolet absorber and coloring material such as pigment and dye.

The thickness of the receiving layer is preferably 1 μm or more and 5 μm or less, and more preferably 1 μm or more and 3 μm or less. When the thickness of the receiving layer is within the above numerical range, a better unevenness can be imparted to the surface of the receiving layer.

To form the receiving layer, the above material is dispersed or dissolved in water or a suitable solvent to obtain a coating liquid for forming the receiving layer, which is used as a roll coater, a reverse roll coater, a gravure coater, a reverse gravure coater, a bar coater and a rod. It can be formed by applying it on a substrate by a known means such as a coater to form a coating film, and then drying the coating film.

(Foam layer)
The foamed layer contains foamed particles, and the foaming temperature of the foamed particles is preferably 140 ° C. or higher and 200 ° C. or lower, more preferably 145 ° C. or higher and 200 ° C. or lower, and 150 ° C. or higher and 200 ° C. or lower. Is more preferable.
By setting the foaming temperature of the foamed particles within the above numerical range, it is possible to suppress the foaming of the foamed particles due to heating during thermal transfer of the transfer layer onto the transfer material and at the time of image formation on the receiving layer, and to the receiving layer. It is possible to improve the dyeing property of the dye and provide a printed matter in which a high-quality image without blurring or cracking is formed.
Further, in the foaming step, it is not necessary to apply excessively high heat, and the re-sublimation of the sublimation dye used for image formation can be prevented.

The volume average particle diameter of the foamed particles before foaming is preferably 10 μm or more and 50 μm or less, more preferably 15 μm or more and 40 μm or less, further preferably 15 μm or more and 35 μm or less, and 20 μm or more. It is particularly preferably 30 μm or less. By setting the volume average particle diameter of the foamed particles within the above numerical range, it is possible to impart a good unevenness to the receiving layer after foaming while maintaining the coatability of the coating liquid at the time of forming the foamed layer. The design of the particle can be further improved.
The foamed layer included in the thermal transfer sheet of the present invention may contain two or more types of foamed particles having different volume average particle diameters. In the present invention, the volume average particle size can be determined by using a laser diffraction type particle size distribution measuring device in accordance with JIS K 5600-9-3.
The volume average particle diameter of the foamed particles after foaming is preferably 30 μm or more and 500 μm or less, more preferably 40 μm or more and 450 μm or less, and further preferably 45 μm or more and 400 μm or less.

The content of the foamed particles in the foamed layer is preferably 30% by mass or more and 80% by mass or less, and more preferably 50% by mass or more and 80% by mass or less. By setting the content of the foamed particles in the foamed layer within the above numerical range, it is possible to impart a good unevenness to the receiving layer after foaming while maintaining the coatability of the coating liquid at the time of forming the foamed layer. The design of the printed matter can be further improved.

In one embodiment, the foamed particles are microcapsule type foamed particles. In the present invention, the microcapsule type foamed particles have a foaming agent encapsulated in fine particles composed of a thermoplastic resin, and by heating to a foaming temperature or higher, the thermoplastic resin is softened and encapsulated inside. Refers to particles whose volume increases due to the vaporization pressure of the foaming agent.
As the foaming agent to be sealed in the thermoplastic fine particles, low boiling point hydrocarbons such as propane, butane, isobutane, and isopentane, and a mixture of these hydrocarbons and water-insoluble petroleum ether can be used.
The thermoplastic resin can be used without particular limitation as long as it has a softening point of 40 ° C. or higher and 120 ° C. or lower.
The foamed layer may contain two or more of the above-mentioned foamed particles.

In one embodiment, the foam layer contains a binder resin, for example, a polyolefin resin, a vinyl resin such as a vinyl chloride-vinyl acetate copolymer, a polyester resin, a polystyrene resin, a polyamide resin, a cellulose resin, and a polycarbonate. Examples thereof include based resins and (meth) acrylic resins. Among these, polyester-based resins and vinyl-based resins are preferable because the receiving layer can impart a good unevenness.

The content of the binder resin contained in the foam layer is preferably 20% by mass or more and 70% by mass or less, and more preferably 30% by mass or more and 50% by mass or less. By setting the content of the binder resin in the foamed layer within the above numerical range, a good unevenness can be given to the receiving layer, and the design of the printed matter can be further improved.

Also, in one embodiment, the foam layer comprises a foaming aid. Examples of the foaming aid include zinc oxide, lead sulfate, urea, zinc stearate and the like.

In addition, the foamed layer may contain the above-mentioned additives as long as the characteristics of the present invention are not impaired.

The thickness of the foamed layer of the foamed particles before foaming is preferably 3 μm or more and 50 μm or less, and more preferably 5 μm or more and 50 μm or less. When the thickness of the foamed layer is within the above numerical range, a good unevenness can be given to the receiving layer, and the design of the printed matter can be further improved.

To form the foam layer, the above material is dispersed or dissolved in water or an appropriate solvent to obtain a coating liquid for forming the foam layer, which is used as a roll coater, a reverse roll coater, a gravure coater, a reverse gravure coater, a bar coater and a rod. It can be formed by applying it on the receptor by a known means such as a coater to form a coating film, and then drying the coating film.
In the case of microcapsule type foamed particles, the foamed particles may be an aqueous coating film formed by dispersing or dissolving the above-mentioned material in water, coating and drying in consideration of the influence of a solvent on the microcapsules. preferable.

(Adhesive layer)
In one embodiment, the transfer layer comprises an adhesive layer. By providing the adhesive layer, the adhesiveness of the transfer layer to the transferred body can be improved.

The adhesive layer contains a thermoplastic resin that softens when heated and exhibits adhesiveness, and includes, for example, polyester resins, vinyl chlorides, vinyl acetates, and vinyl resins such as ethylene-vinyl acetate copolymers. Examples thereof include (meth) acrylic resin, (meth) acrylic resin, polyurethane resin, cellulose resin, melamine resin, polyamide resin, polyolefin resin, and styrene resin.

The thickness of the adhesive layer is preferably 0.5 μm or more and 10 μm or less, and more preferably 1 μm or more and 5 μm or less.
By setting the thickness of the adhesive layer within the above numerical range, it is possible to improve the adhesiveness to the transferred object while maintaining the transferability of the transfer layer.

To form the adhesive layer, the above materials are dispersed or dissolved in water or a suitable solvent to obtain a coating liquid for forming the adhesive layer, which is used as a roll coater, a reverse roll coater, a gravure coater, a reverse gravure coater, a bar coater and a rod. It can be formed by applying it on a substrate by a known means such as a coater to form a coating film, and then drying the coating film.

(Dye layer)
In one embodiment, the thermal transfer sheet according to the invention comprises a dye layer.
The dye layer is a layer containing a sublimation dye, and examples thereof include a yellow dye layer, a magenta dye layer, a cyan dye layer, and the like, and the thermal transfer sheet is provided with one or more of these dye layers in a surface-sequential manner. Can be done.

The sublimation dye is not particularly limited, but a dye having a sufficient coloring concentration and not discoloring or fading due to light, heat, temperature or the like is preferable. Examples of such sublimative dyes include diarylmethane dyes, triarylmethane dyes, thiazole dyes, merocyanine dyes, pyrazolone dyes, methine dyes, indian aniline dyes, acetophenone azomethine, pyrazoloazomethine, and imidazole. Azomethine dyes such as azomethin, imidazola azomethin, pyridone azomethin, xanthene dyes, oxazine dyes, cyanostyrene dyes such as dicyanostyrene and tricyanostyrene, thiazine dyes, azine dyes, acrydin dyes, benzeneazo dyes, Azo dyes such as pyridone azo, thiophen azo, isothiazole azo, pyrrol azo, pyrazole azo, imidazole azo, thiadiazol azo, triazole azo, disazo, spiropyran dyes, indolinospiropirane dyes, fluorane dyes, rhodamine lactam dyes, naphthoquinone. Examples thereof include dyes, anthraquinone dyes, and quinophthalone dyes. More specifically, MSRedG (manufactured by Mitsui Toatsu Kagaku Co., Ltd.), Macrolex Red Violet R (manufactured by Bayer Akzien Gezel Shaft), CeresRed 7B (manufactured by Bayer Akzien Gezel Shaft), Samaroon Red F3BS (manufactured by Bayer Akzien Gezel Shaft). Red dyes such as Mitsubishi Chemical Co., Ltd., Holon Brilliant Yellow 6GL (manufactured by Clariant), PTY-52 (manufactured by Mitsubishi Chemical Co., Ltd.), Macrolex Yellow 6G (manufactured by Bayer Akzien Gezel Shaft), etc. Yellow dye, Kayaset (registered trademark) Blue 714 (manufactured by Nippon Kayaku Co., Ltd.), Waxoline Blue AP-FW (manufactured by ICI), Holon Brilliant Blue SR (manufactured by Sand Co., Ltd.), MS Blue 100 (manufactured by Sand Co., Ltd.) Mitsui Toatsu Chemical Co., Ltd.), C.I. I. Blue dyes such as Solvent Blue 22 can be mentioned.

The dye layer is a cellulose-based resin such as ethyl cellulose, hydroxyethyl cellulose, ethyl hydroxycellulose, hydroxypropyl cellulose, methyl cellulose, cellulose acetate, cellulose butyrate, or vinyl-based resin such as polyvinyl alcohol, polyvinyl acetate, polyvinyl butyral, polyvinyl acetoacetal, and polyvinylpyrrolidone. It is preferable to contain a resin, a (meth) acrylic resin such as poly (meth) acrylate and poly (meth) acrylamide, a polyurethane resin, a polyamide resin, a binder resin such as a polyester resin, and the like.

The thickness of the dye layer is not particularly limited, and can be, for example, 0.2 μm or more and 2 μm.

To form the dye layer, the above material is dispersed or dissolved in water or an appropriate solvent to obtain a coating liquid for forming the dye layer, which is used as a roll coater, reverse roll coater, gravure coater, reverse gravure coater, bar coater and rod. It can be formed by applying it on a base material or a primer layer by a known means such as a coater to form a coating film, and then drying the coating film.

(Primer layer)
In one embodiment, the thermal transfer sheet according to the invention comprises a primer layer between the dye layer and the substrate. The primer layer is provided to improve the adhesion between the base material and the dye layer and to prevent so-called abnormal transfer in which the entire dye layer is removed during transfer.

The primer layer may contain a polyester-based resin, a polyamide-based resin, a polyolefin-based resin, a vinyl-based resin, a (meth) acrylic-based resin, a cellulose-based resin, and the like.

The thickness of the primer layer is not particularly limited, and can be, for example, 0.05 μm or more and 0.5 μm.

To form the primer layer, the above material is dispersed or dissolved in water or an appropriate solvent to prepare a coating liquid for forming the primer layer, which is used as a roll coater, a reverse roll coater, a gravure coater, a reverse gravure coater, a bar coater and a rod. It can be formed by applying it on a substrate by a known means such as a coater to form a coating film, and then drying the coating film.

(Colored layer)
In one embodiment, the thermal transfer sheet according to the present invention comprises a colored layer, which is transferred onto the transferee at the time of transfer.

The colored layer contains a coloring agent such as carbon black, an inorganic pigment, or an organic pigment. More specifically, carbon black such as lamp black, graphite, niglosin dye and the like can be mentioned.

The colored layer contains a binder resin such as a cellulose resin, a vinyl resin, a (meth) acrylic resin, a polyurethane resin, a polyamide resin, a polyester resin, a polyurethane resin, a melamine resin, and a melamine resin. Is preferable.

The thickness of the colored layer is not particularly limited, and can be, for example, 0.2 μm or more and 2 μm.

To form the colored layer, the above material is dispersed or dissolved in water or an appropriate solvent to obtain a coating liquid for forming the colored layer, which is used as a roll coater, a reverse roll coater, a gravure coater, a reverse gravure coater, a bar coater and a rod. It can be formed by applying it on a base material or a release layer by a known means such as a coater to form a coating film, and then drying the coating film.

(Release layer)
In one embodiment, the thermal transfer sheet according to the invention comprises a release layer between the colored layer and the substrate.
The release layer is a layer provided on the base material, is peeled off from the base material, transferred, and is located on the outermost surface of the protective layer after transfer.

The release layer contains, for example, a (meth) acrylic resin, a cellulose resin, a vinyl resin, a polyurethane resin, a silicone resin, a fluorine resin, a silicone wax, a fluorine-modified resin, a wax, and the like.

Examples of the wax include natural waxes such as beeswax, whale wax, wood wax, rice bran wax, carnauba wax, candelilla wax and montan wax, paraffin wax, microcrystallin wax, oxide wax, ozokelite, selecin, ester wax and polyethylene wax. Higher saturated fatty acids such as synthetic wax, margaric acid, lauric acid, myristic acid, palmitic acid, stearic acid, floic acid and behenic acid, higher saturated monovalent alcohols such as stearyl alcohol and behenyl alcohol, and higher esters such as sorbitan fatty acid ester. , Higher fatty acid amides such as stearate amides and oleic acid amides.

Further, the release layer may contain rubbers such as isoprene rubber, butyl rubber and nitrile rubber. Since the release layer contains rubbers, the elasticity of the release layer can be improved, and the adhesion between the thermal transfer sheet and the transferred body can be improved.

The thickness of the release layer is not particularly limited, and can be, for example, 0.1 μm or more and 5 μm or less.

To form the release layer, the above material is dispersed or dissolved in water or an appropriate solvent to obtain a coating liquid for forming the release layer, which is used as a roll coater, a reverse roll coater, a gravure coater, a reverse gravure coater, a bar coater and a rod. It can be formed by applying it on a substrate by a known means such as a coater to form a coating film, and then drying the coating film.

(Back layer)
In one embodiment, the thermal transfer sheet of the present invention includes a back surface layer on a surface opposite to the surface on which the transfer layer of the base material is provided. When the thermal transfer sheet is provided with a back layer, it is possible to prevent sticking, wrinkles, and the like due to heating during thermal transfer.

In one embodiment, the back layer comprises a binder resin. Examples of the binder resin include cellulose-based resin, styrene-based resin, vinyl-based resin, polyester-based resin, polyurethane-based resin, silicone-modified urethane-based resin, silicone resin, fluorine-modified urethane-based resin, and (meth) acrylic-based resin. Can be mentioned.
Among these, a silicone resin, specifically, an acrylic-modified silicone resin is preferable from the viewpoint of preventing seizure of the thermal head and the back layer and generation of debris.

Further, in one embodiment, the back layer contains a two-component curable resin as a binder resin, which is cured by being used in combination with an isocyanate compound or the like. Examples of such a resin include polyvinyl acetal-based resins and polyvinyl butyral-based resins.
As the isocyanate compound, conventionally known isocyanate compounds can be used without particular limitation, but among them, it is desirable to use an adduct of an aromatic isocyanate. Examples of the aromatic polyisocyanate include 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, or a mixture of 2,4-toluene diisocyanate and 2,6-toluene diisocyanate, 1,5-naphthalene diisocyanate, and trizine diisocyanate. Examples thereof include p-phenylene diisocyanate, trans-cyclohexane-1,4-diisocyanate, xylylene diisocyanate, triphenylmethane triisocyanate and tris (isocyanisocyanene) thiophosphate, and particularly 2,4-toluene diisocyanate and 2,6-toluene diisocyanate. Or, a mixture of 2,4-toluene diisocyanate and 2,6-toluene diisocyanate is preferable.

In one embodiment, the back layer comprises inorganic or organic microparticles. By including such fine particles in the back layer, it is possible to further prevent the occurrence of sticking, wrinkles, etc. due to heating during thermal transfer.

Examples of the inorganic fine particles include clay minerals such as talc and kaolin, carbonates such as calcium carbonate and magnesium carbonate, hydroxides such as aluminum hydroxide and magnesium hydroxide, sulfates such as calcium sulfate, and oxides such as silica. , Graphite, sulphate, and inorganic fine particles such as boron nitride.
The organic fine particles include organic resin fine particles made of (meth) acrylic resin, Teflon (registered trademark) resin, silicone resin, lauroyl resin, phenol resin, acetal resin, styrene resin, polyamide resin and the like, or Examples thereof include crosslinked resin fine particles obtained by reacting these with a crosslinker.

The thickness of the back layer is preferably 0.01 μm or more and 5 μm or less, and more preferably 0.03 μm or more and 2 μm or less.

The back layer is formed by dispersing or dissolving the above material in water or a suitable solvent to obtain a coating liquid for forming the back layer, which is used as a roll coater, a reverse roll coater, a gravure coater, a reverse gravure coater, a bar coater and a rod. It can be formed by applying it on a substrate by a known means such as a coater to form a coating film, and then drying the coating film.

(Manufacturing method of photographic paper)
In the method for producing a printed matter according to the present invention, the transfer layer is covered by superimposing the above-mentioned thermal transfer sheet and the transferred body and heating the transfer layer from the surface opposite to the surface on which the transfer layer is provided. A step of transferring onto a transfer body (hereinafter, simply referred to as a transfer step),
A step of forming an image on the receiving layer provided in the transfer layer (hereinafter, simply referred to as an image forming step) and
It is characterized by including a step of heating the transferred body to foam the foamed particles contained in the foamed layer (hereinafter, simply referred to as a foaming step).
Hereinafter, each step will be described.

(Transfer process)
The transfer layer included in the thermal transfer sheet is transferred onto the transferred body by the transfer step included in the method according to the present invention.
In the transfer step, the thermal transfer sheet is heated by a thermal head or the like from a surface opposite to the surface on which the transfer layer is provided. The heating temperature at this time is more preferably less than 140 ° C., whereby the foaming of the foamed particles contained in the foamed layer can be suppressed, and a high-quality image can be formed on the receiving layer after transfer.

The transfer material is not particularly limited, and paper such as resin film, natural fiber paper, and coated paper, glass, metal, wood, and the like can be used. Further, these laminated bodies may be used as a transfer body.

(Image formation process)
The method according to the present invention includes the step of forming an image on the receiving layer transferred onto the transferred material. The heating temperature at this time is more preferably less than 140 ° C. By setting the heating temperature within the above numerical range, the foaming of the foamed particles contained in the foamed layer can be suppressed, and a high-quality image can be formed on the receiving layer.

When the thermal transfer sheet according to the present invention includes a dye layer and a colored layer, the thermal transfer sheet may be used for forming an image, or other thermal transfer sheets may be used.
Further, by forming an image before the foaming step, it is possible to improve the dyeing property of the dye on the receiving layer, and it is possible to form a high-quality image without blurring or cracking.

(Foam process)
The method according to the present invention includes a step of heating the transferred body to foam the foamed particles contained in the foamed layer after the image formation. The heating temperature at this time is preferably 140 ° C. or higher and 250 ° C. or lower. By setting the heating temperature within the above numerical range, the foamed particles contained in the foamed layer can be satisfactorily foamed while preventing the re-sublimation of the sublimating dye from the image formed on the receiving layer, which is good for the receiving layer. It is possible to give a feeling of unevenness.

Next, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples. Below, for those with a description of solid content, the composition before conversion to solid content is shown.

Example 1
A back layer having a thickness of 1 μm was formed by applying a coating liquid for forming a back layer having the following composition on one surface of a PET film having a thickness of 5 μm and drying the film.
<Coating liquid for forming the back layer>
-Polyvinyl acetal 36 parts by mass (manufactured by Sekisui Chemical Co., Ltd., trade name: Eslek (registered trademark) KS-1)
25 parts by mass of isocyanate compound (manufactured by DIC Corporation, trade name: Barnock (registered trademark) D750)
・ Silicone resin fine particles 1 part by mass (Momentive Performance Materials Japan LLC, product name: Tospearl (registered trademark) 240)
10 parts by mass of zinc stearyl phosphate (manufactured by Sakai Chemical Industry Co., Ltd., trade name: LBT1830 purification)
・ Zinc stearate 10 parts by mass (manufactured by Sakai Chemical Industry Co., Ltd., trade name: SZ-PF)
・ Polyethylene wax 3 parts by mass (manufactured by Toyo Adre Co., Ltd., polywax 3000)
・ 7 parts by mass of ethoxylated alcohol-modified wax (manufactured by Toyo Adre Co., Ltd., Unitox 750)
-Methyl ethyl ketone (MEK) 200 parts by mass-Toluene 100 parts by mass

A coating solution for forming a receiving layer having the following composition was applied to the other surface of the PET film and dried to form a receiving layer having a thickness of 2 μm.
<Coating liquid for forming a receptive layer>
17 parts by mass of vinyl chloride-vinyl acetate copolymer (manufactured by Nissin Chemical Industry Co., Ltd., trade name: Solvine (registered trademark) CNL, Tg: 76 ° C., Mn: 12,000)
-Epoxy modified silicone oil 3 parts by mass (manufactured by Shin-Etsu Chemical Co., Ltd., product name: KP-1800U)
・ MEK 40 parts by mass ・ Toluene 40 parts by mass

On the receiving layer formed as described above, a coating liquid for forming a foam layer having the following composition is applied so that the coating amount after drying is 10 μm, and the foam layer is formed by drying. rice field.
<Coating liquid for forming foam layer>
15 parts by mass of foamed particles A (Matsumoto Yushi Pharmaceutical Co., Ltd., Matsumoto Microsphere (registered trademark) FN-100MD, foaming temperature 170 ° C., average particle size: 20 μm)
40 parts by mass of polyester resin (manufactured by Toyobo Co., Ltd., trade name: Byronal (registered trademark) 1245, solid content: 30%)
・ 20 parts by mass of water

An adhesive layer for forming an adhesive layer having the following composition was applied onto the foam layer formed as described above and dried to form an adhesive layer having a thickness of 2 μm.
<Coating liquid for forming an adhesive layer>
-Vinyl chloride-vinyl acetate copolymer 20 parts by mass (manufactured by Nissin Chemical Industry Co., Ltd., trade name: Solveine (registered trademark) CNL)
・ MEK 40 parts by mass ・ Toluene 40 parts by mass

A primer layer having a thickness of 0.1 μm was formed by applying a coating solution for forming a primer layer having the following composition and drying it so as to be surface-sequential with the receiving layer formed as described above.
<Coating liquid for forming primer layer>
・ PVP 1.5 parts by mass (manufactured by ASP Japan Co., Ltd., product name: K-90)
・ Alumina sol (solid content: 10%) 35 parts by mass ・ 30 parts by mass of water ・ Isopropyl alcohol (IPA) 33.5 parts by mass

On the primer layer formed as described above, a coating liquid for forming a yellow dye layer, a coating liquid for forming a magenta dye layer, and a coating liquid for forming a cyan dye layer having the following compositions are applied and dried. A yellow dye layer, a magenta dye layer and a cyan dye layer having a thickness of 0.35 μm were formed.
<Coating liquid for forming a yellow dye layer>
-Solvent Yellow 936 parts by mass-Polyvinyl acetal 5 parts by mass (manufactured by Sekisui Chemical Co., Ltd., trade name: Eslek (registered trademark) KS-5)
・ MEK 50 parts by mass ・ Toluene 50 parts by mass <Magenta dye layer forming coating liquid>
・ Disperse thread 60 3 parts by mass ・ Disperse violet 26 4 parts by mass ・ Polyvinyl acetal 5 parts by mass (manufactured by Sekisui Chemical Co., Ltd., trade name: Eslek (registered trademark) KS-5)
・ MEK 50 parts by mass ・ Toluene 50 parts by mass <Coating liquid for forming cyan dye layer>
-Solvent Blue 63 4 parts by mass-Disperse Blue 354 4 parts by mass-Polyvinyl acetal 5 parts by mass (manufactured by Sekisui Chemical Co., Ltd., trade name: Eslek (registered trademark) KS-5)
・ MEK 50 parts by mass ・ Toluene 50 parts by mass

Example 2
Other than changing the foamed particles A contained in the coating liquid for forming the foamed layer to foamed particles B (Matsumoto Yushi Seiyaku Co., Ltd., Matsumoto Microsphere FN-180, foaming temperature 175 ° C., average particle size: 35 μm) Made a thermal transfer sheet in the same manner as in Example 1.

Example 3
The vinyl chloride-vinyl acetate copolymer contained in the coating liquid for forming the receiving layer was changed to a (meth) acrylic resin (manufactured by Mitsubishi Chemical Corporation, trade name: Dianal (registered trademark) BR-83). A thermal transfer sheet was produced in the same manner as in Example 1 except for the above.

Comparative Example 1
The foamed particles A contained in the coating liquid for forming the foamed layer are the foamed particles C (manufactured by Matsumoto Yushi Pharmaceutical Co., Ltd., Matsumoto Microspheres (registered trademark) FN-80GS, foaming temperature 130 ° C., average particle size: 6 μm). A thermal transfer sheet was produced in the same manner as in Example 1 except that it was changed to.

Comparative Example 2
The foamed particles A contained in the coating liquid for forming the foamed layer are the foamed particles D (Matsumoto Yushi Seiyaku Co., Ltd., Matsumoto Microsphere (registered trademark) F-36, foaming temperature 115 ° C., average particle size: 10 μm). A thermal transfer sheet was produced in the same manner as in Example 1 except that it was changed to.

Comparative Example 3
A thermal transfer sheet was produced in the same manner as in Example 3 except that the foamed particles A contained in the coating liquid for forming the foamed layer were changed to the foamed particles C.

<< Printing aptitude evaluation test >>
Using a PVC card as the heat transfer sheet and the transfer body obtained in Example 1, the adhesive layer, the foam layer and the receptive layer are heat-transferred onto the transfer body, and the heat transfer sheet is included in the dye layer provided. An image was formed by sublimating the sublimating dye on the receptive layer formed on the transferred material, and an imprint was obtained.
A thermal transfer printer was used for thermal transfer and image formation of the adhesive layer, the foam layer and the receiving layer under the following conditions.
(Thermal transfer conditions)
-Printer: Card printer-Printing pressure: 2.2 kg / inch
-Printing speed: 3 msec. / Line
・ Thermal head resolution: 300 dpi
-Printing energy: 0.26 mJ / dot

The print was then placed in an oven and heated at 200 ° C. for 5 minutes. The foamed particles contained in the foamed layer were completely foamed.

The image formed as described above was visually observed, and the print suitability was evaluated according to the following evaluation criteria. The evaluation results are summarized in Table 1.
The same evaluation was performed on the thermal transfer sheets obtained in the other examples and comparative examples, and the results are summarized in Table 1.
<< Appropriate printing >>
(Evaluation criteria)
A: After the foamed layer was transferred, the foamed layer did not foam at all when the image was formed, and the image could be formed satisfactorily.
B: After the foamed layer was transferred, the foamed layer foamed when the image was formed, and the formed image was cracked, but there was no problem in actual use.
NG: After transferring the foamed layer, the foamed layer completely foamed at the time of image formation, and the image could not be formed.

<< Unevenness Evaluation Test >>
The surface of the printed matter obtained by the above-mentioned print suitability test on the receiving layer side was visually observed, and the degree of the imparted unevenness was evaluated according to the following evaluation criteria. The evaluation results are summarized in Table 1.
(Evaluation criteria)
A: A good unevenness was imparted to the surface of the receiving layer, and a printed matter having extremely high design was obtained.
B: The surface of the receiving layer was given an unevenness, and a highly designed printed matter was obtained.
C: A feeling of unevenness on the surface of the receiving layer was given to some extent.
NG: No unevenness could be observed on the surface of the receiving layer.

10: Thermal transfer sheet 11: Base material 12: Transfer layer 13: Receptive layer 14: Foam layer 15: Adhesive layer 16, 17, 18: Dye layer 19: Primer layer 20: Colored layer 21: Release layer 22: Back layer

Claims (10)

A thermal transfer sheet including a base material and a transfer layer having a receiving layer and a foaming layer in this order.
A step of preparing a thermal transfer sheet in which the foamed layer contains foamed particles having a foaming temperature of 140 ° C. or higher and 200 ° C. or lower.
It said thermal transfer sheet, superposing a transferred object, wherein the opposite surface from that of the transfer layer is provided face of the thermal transfer sheet, by heating the thermal transfer sheet, the transfer layer on the material to be transferred And the process of transferring
A step of forming an image on the receiving layer included in the transfer layer, and
A method for producing a printed matter, which comprises a step of heating the transferred body to foam the foamed particles contained in the foamed layer. The method for producing a printed matter according to claim 1 , wherein the heating temperature in the transfer step is less than 140 ° C. The method for producing a printed matter according to claim 1 or 2 , wherein the heating temperature in the foaming step is 140 ° C. or higher and 250 ° C. or lower. The method for producing a printed matter according to any one of claims 1 to 3, wherein the volume average particle diameter of the foamed particles is 10 μm or more and 50 μm or less. The method for producing a printed matter according to any one of claims 1 to 4, wherein the content of the foamed particles in the foamed layer is 30% by mass or more and 80% by mass or less. The method for producing a printed matter according to any one of claims 1 to 5 , wherein the receiving layer contains a vinyl chloride-vinyl acetate copolymer. The method for producing a printed matter according to any one of claims 1 to 6 , wherein the thickness of the receiving layer is 1 μm or more and 5 μm or less. The method for producing a printed matter according to any one of claims 1 to 7 , further comprising an adhesive layer on the foamed layer. The method for producing a printed matter according to any one of claims 1 to 8 , wherein the foamed layer is an aqueous coating film. The method for producing a printed matter according to any one of claims 1 to 9 , further comprising a dye layer so as to be surface-sequential with the transfer layer.

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