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

Abstract

To provide a thermal transfer image receiving sheet excellent in conveyance properties at printing, while preventing conveyance scratches on a back side from occurring.SOLUTION: A thermal transfer image receiving sheet includes a back layer, a back primer layer, a substrate and a reception layer in this order. The back primer layer includes a pigment and a resin material containing an urethane resin component. In the back primer layer, a mass ratio of a content of the pigment and a content of the resin material (a content of the pigment / a content of the resin material) is 1.00 to 3.00. Thickness of the back primer layer is 0.20 to 0.90 μm.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] Among various image forming methods known in the art, the dye-sublimation thermal transfer method allows for free adjustment of density gradation, excellent reproducibility of intermediate colors and gradations, and enables the formation of high-quality images comparable to silver halide photography.

[0003] In the dye-sublimation thermal transfer method, a thermal transfer sheet having a sublimation transfer type color material layer containing a sublimation dye and a thermal transfer image receiving sheet having a receiving layer are usually used. For example, the thermal transfer sheet and the thermal transfer image receiving sheet are superimposed, and then the thermal transfer sheet is heated by a heat generating member such as a thermal head of the printer, so that the sublimation dye in the sublimation transfer type color material layer is transferred to the receiving layer to form an image, thereby obtaining a printed matter (for example, see Patent Document 1).

[0004] Conventional thermal transfer image receiving sheets have not been sufficiently easy to transport when printed using, for example, a grip roller type printer, etc. In order to improve the transportability, a thermal transfer image receiving sheet having a grip layer on the back surface has been proposed (for example, see Patent Document 2). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2001-39043 A [Patent Document 2] Japanese Patent Application Publication No. 11-115328 Summary of the Invention [Problem to be solved by the invention]

[0006] If the transportability of the thermal transfer image receiving sheet during printing could be improved, high-quality images could be achieved. However, with conventional thermal transfer image receiving sheets, depending on the printer used, the transportability is insufficient, and double feeding occurs, for example, and transport scratches are caused on the back side of the printed matter by the transport roller, which can degrade the quality of the printed matter.

[0007] The problem to be solved by the present disclosure is to provide a thermal transfer image receiving sheet that has excellent transportability during printing and suppresses the occurrence of transport scratches on the back side, and also to provide a method for producing a printed matter using the thermal transfer image receiving sheet, and a printed matter. [Means for solving the problem]

[0008] The thermal transfer image receiving sheet of the present disclosure is a thermal transfer image receiving sheet comprising a back layer, a back primer layer, a substrate, and a receiving layer in this order, the back primer layer contains a pigment and a resin material including a urethane resin component, the mass ratio of the pigment content to the resin material content in the back primer layer (pigment content / resin material content) is 1.00 or more and 3.00 or less, and the thickness of the back primer layer is 0.20 μm or more and 0.90 μm or less.

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

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

[0011] According to the present disclosure, it is possible to provide a thermal transfer image receiving sheet that has excellent transportability during printing and suppresses the occurrence of transport scratches on the back side, and also to provide a method for producing a printed matter using the thermal transfer image receiving sheet, and a printed matter. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a schematic cross-sectional view showing one embodiment of the thermal transfer image-receiving sheet of the present disclosure. [Diagram 2] FIG. 2 is a schematic cross-sectional view showing one embodiment of the thermal transfer image receiving sheet of the present disclosure. [Diagram 3] FIG. 3 is a schematic cross-sectional view showing one embodiment of a print material of the present disclosure. [Figure 4] FIG. 4 is a schematic cross-sectional view showing one embodiment of a print material of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

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

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

[0015] [Thermal transfer image receiving sheet] The thermal transfer image receiving sheet of the present disclosure includes a back layer, a back primer layer, a substrate, and a receiving layer in this order in the thickness direction. The thermal transfer image receiving sheet 1 of one embodiment shown in FIG. 1 includes a back layer 14, a back primer layer 12, a substrate 10, and a receiving layer 20 in this order in the thickness direction. The thermal transfer image receiving sheet 1 of one embodiment shown in FIG. 2 includes a back layer 14, a back primer layer 12, a substrate 10, a heat insulating layer 16, a primer layer 18, and a receiving layer 20 in this order in the thickness direction. An adhesive layer (not shown) may be provided between the substrate 10 and the heat insulating layer 16. Hereinafter, each layer of the thermal transfer image receiving sheet of the present disclosure will be described in detail.

[0016] <Base material> Substrates include, for example, film and paper substrates.

[0017] The film may be, for example, a film made of a resin material (hereinafter also referred to as a "resin film"). Examples of the resin material include polyesters such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate; polyolefins such as polyethylene, polypropylene, and polymethylpentene; vinyl resins such as polyvinyl chloride, polyvinyl acetate, and vinyl chloride-vinyl acetate copolymers; (meth)acrylic resins such as polyacrylate, polymethacrylate, and polymethyl methacrylate; styrene resins such as polystyrene; polycarbonate; and ionomer resins.

[0018] In the present disclosure, "(meth)acrylic" includes both "acrylic" and "methacrylic." Also, "(meth)acrylate" includes both "acrylate" and "methacrylate."

[0019] Examples of the paper substrate include condenser paper, glassine paper, parchment paper, synthetic paper, wood-free paper, art paper, coated paper, uncoated paper, cast-coated paper, wallpaper, cellulose fiber paper, synthetic resin-implanted paper, backing paper, and impregnated paper, such as synthetic resin-impregnated paper, emulsion-impregnated paper, and synthetic rubber latex-impregnated paper.

[0020] When the substrate is a resin film, the resin film may be a stretched film or an unstretched film. From the viewpoint of mechanical strength, it is preferable to use a uniaxially or biaxially stretched film as the substrate.

[0021] The substrate is preferably a resin film, more preferably a film made of polyester (polyester film) and a film made of polyolefin (polyolefin film), and further preferably a polyethylene terephthalate film and a polypropylene film. The resin film may be a stretched film.

[0022] The above-mentioned laminate of the resin film and the paper substrate (laminated substrate) may be used as the substrate. The laminate can be produced, for example, by using the dry lamination method, the wet lamination method, and the extrusion method. For example, a laminate of a polyester film or a polyolefin film and a paper substrate is preferred, and a laminate of a polyethylene terephthalate film or a polypropylene film and a paper substrate is more preferred. The resin film may be a stretched film.

[0023] From the viewpoint of mechanical strength, the thickness of the substrate is preferably 20 μm or more and 500 μm or less, more preferably 50 μm or more and 400 μm or less, and further preferably 100 μm or more and 300 μm or less.

[0024] <Back layer> The thermal transfer image receiving sheet of the present disclosure includes a backing layer on the surface of the substrate opposite to the receiving layer. By providing the back surface layer, for example, the transportability during printing of the thermal transfer image receiving sheet, specifically, the transportability during printing using a grip roller type printer, etc. By providing the back surface layer, for example, the writability on the back side of the thermal transfer image receiving sheet can be improved.

[0025] In one embodiment, the back surface layer contains a resin material. Examples of the resin material include polyvinyl acetal resins such as polyvinyl butyral resin and polyvinyl acetoacetal resin; vinyl resins such as polyvinyl chloride, polyvinyl acetate, vinyl chloride-vinyl acetate copolymer and polyvinyl alcohol resin; polyolefin, (meth)acrylic resin, styrene resin, polyester, polyamide, polyimide, polycarbonate, and cellulose resin. The back surface layer can contain one or more types of resin materials.

[0026] The resin material may be a crosslinked product of a resin having a functional group such as a hydroxyl group, with a crosslinking agent capable of reacting with the functional group. Examples of the crosslinking agent include metal chelate-based crosslinking agents such as titanium chelate compounds and zirconium chelate compounds, isocyanate-based crosslinking agents, epoxy-based crosslinking agents, oxazoline-based crosslinking agents, and melamine-based crosslinking agents. One or more types of crosslinking agents can be used. Among these, metal chelate-based crosslinking agents are preferred. For example, a crosslinked product of a polyvinyl acetal resin or a polyvinyl alcohol resin with a metal chelate-based crosslinking agent is preferred.

[0027] The amount of the crosslinking agent used is preferably 0.1 parts by mass or more and 20 parts by mass or less, more preferably 0.5 parts by mass or more and 10 parts by mass or less, and even more preferably 1 part by mass or more and 5 parts by mass or less, based on 100 parts by mass of the resin having a functional group such as a hydroxyl group.

[0028] The back layer may contain additives. Examples of additives include plasticizers, coloring inhibitors, surfactants, fluorescent whitening agents, matting agents, deodorants, flame retardants, antistatic agents, friction reducers, slip agents, dispersants, UV absorbers, antioxidants, weather stabilizers, fillers, and colorants such as pigments and dyes. The back layer may contain one or more additives.

[0029] The thickness of the back layer is preferably 0.05 μm or more and 2.00 μm or less, more preferably 0.13 μm or more and 1.30 μm or less. The coating amount of the back layer in a dry state is preferably 0.10 g / m 2 More than 5.0g / m2 Less than 0.10 g / m 2 More than 3.0g / m 2 More preferably, 0.20 g / m or less 2 More than 2.0g / m 2 According to such an embodiment, for example, the conveyability and abrasion resistance during printing of the thermal transfer image receiving sheet can be further improved.

[0030] The back surface layer can be formed, for example, by dispersing or dissolving the above-mentioned materials in water or a suitable organic solvent to prepare a coating liquid, applying the coating liquid onto the back surface primer layer by a known coating means to form a coating film, and drying the coating film. Examples of the coating means include roll coating, reverse roll coating, gravure coating, reverse gravure coating, bar coating, and rod coating.

[0031] <Back primer layer> The thermal transfer image receiving sheet of the present disclosure includes a specific back primer layer between the substrate and the back layer, which is described below. The back primer layer is provided for the purpose of improving the adhesion between the substrate and the back layer and imparting the concealment property of the base, for example.

[0032] When a conventional thermal transfer image receiving sheet is used, depending on the type of thermal transfer printer (e.g., a grip roller type printer), double feeding may occur during printing. In the present disclosure, a specific back primer layer is provided between the substrate and the back layer, so that double feeding during printing is suppressed and transportability is excellent.

[0033] In addition, when a conventional thermal transfer image receiving sheet is used, depending on the type of thermal transfer printer, the back surface of the printed matter may be scratched by the transport roller, resulting in a decrease in the quality of the printed matter. This is believed to be because the back surface layer of the thermal transfer image receiving sheet is prone to peeling and scratches. In the present disclosure, a specific back surface primer layer is provided between the substrate and the back surface layer, so that peeling of the back surface layer and therefore the occurrence of transport scratches are also suppressed. Therefore, according to the present disclosure, a high-quality printed matter can be realized.

[0034] The back surface primer layer contains a resin material containing a urethane resin component. The urethane resin component is, for example, at least one selected from a urethane resin and a crosslinked product of the urethane resin with a crosslinking agent for urethane resin.

[0035] The urethane resin is a polymer of polyol and polyisocyanate, and examples thereof include polyester-based urethane resin, polyether-based urethane resin, polylactone-based urethane resin, polycarbonate-based urethane resin, polyester-polycarbonate-based urethane resin, castor oil-based urethane resin, polyolefin-based urethane resin, polybutadiene-based urethane resin, polyisoprene-based urethane resin, and poly(meth)acrylic-based urethane resin.

[0036] The polyol is a compound having two or more hydroxyl groups. The number of hydroxyl groups in the polyol is preferably 2 or more and 3 or less. Examples of the polyol include polyester polyol, polyether polyol, polylactone polyol, polycarbonate polyol, polyester polycarbonate polyol, castor oil polyol, polyolefin polyol, polybutadiene polyol, polyisoprene polyol, and poly(meth)acrylic polyol. One or more types of polyols can be used.

[0037] The polyisocyanate is a compound having two or more isocyanate groups. The number of isocyanate groups in the polyisocyanate is preferably 2 or more and 9 or less. Examples of the polyisocyanate include aromatic polyisocyanates such as phenylene diisocyanate, biphenylene diisocyanate, diphenylmethane diisocyanate, triphenylmethane triisocyanate, tolylene diisocyanate, xylylene diisocyanate, naphthalene diisocyanate, and diphenyl ether diisocyanate; alicyclic polyisocyanates such as cyclopentylene diisocyanate, cyclohexylene diisocyanate, isophorone diisocyanate, and dicyclohexylmethane diisocyanate; aliphatic polyisocyanates such as butylene diisocyanate and hexamethylene diisocyanate; and polyol adducts of these compounds, biuret bodies of these compounds, and trimers having an isocyanurate ring of these compounds. The polyisocyanate may be used alone or in combination.

[0038] Examples of the polyol adduct include trimethylolpropane adducts such as trimethylolpropane / tolylene diisocyanate trimer adduct and trimethylolpropane / hexamethylene diisocyanate trimer adduct. Examples of the trimer include an isocyanurate of hexamethylene diisocyanate.

[0039] The weight average molecular weight (Mw) of the urethane resin is preferably from 1,000 to 200,000, and more preferably from 10,000 to 100,000. Mw is measured by gel permeation chromatography (GPC) and is expressed as a standard polystyrene equivalent value.

[0040] The softening point of the urethane resin is preferably 50° C. or higher, more preferably 55° C. or higher and 140° C. or lower, even more preferably 60° C. or higher and 120° C. or lower, and particularly preferably 80° C. or higher and 100° C. The softening point is measured in accordance with JIS K7196.

[0041] The glass transition temperature (Tg) of the urethane resin is preferably −50° C. or higher and 10° C. or lower, more preferably −40° C. or higher and 5° C. or lower, still more preferably −28° C. or higher and 5° C. or lower, and particularly preferably −20° C. or higher and 5° C. or lower. Tg is measured by differential scanning calorimetry (DSC) in accordance with JIS K7121.

[0042] As the crosslinking agent for urethane resin, an isocyanate-based crosslinking agent is preferred. As the isocyanate-based crosslinking agent, for example, the polyisocyanate described above as the raw material of urethane resin can be mentioned. One or more kinds of isocyanate-based crosslinking agents can be used. By using the urethane resin and the crosslinking agent in combination in this way, for example, the adhesion between the substrate / back surface layer can be further improved.

[0043] The amount of the crosslinking agent for urethane resin used is preferably 0.5 parts by mass or more and 30 parts by mass or less, more preferably 1 part by mass or more and 25 parts by mass or less, and even more preferably 5 parts by mass or more and 20 parts by mass or less, based on 100 parts by mass of the urethane resin. The urethane resin and the isocyanate-based crosslinking agent are preferably used in an amount such that the ratio (NCO / OH) of the number of isocyanate groups of the isocyanate-based crosslinking agent to the number of hydroxyl groups of the urethane resin is 0.3 to 3.5. This tends to further improve the adhesion between the substrate and the back layer, for example.

[0044] The back surface primer layer can contain one or more types of urethane resin components.

[0045] The back primer layer may further contain a resin material other than the urethane resin component, such as polyolefin, (meth)acrylic resin, vinyl resin, polyvinyl acetal resin, styrene resin, polyester, polyamide, polyimide, polycarbonate, and cellulose resin.

[0046] In the back surface primer layer, the content of the urethane resin component in the resin material is preferably 70 mass % or more, more preferably 80 mass % or more, and even more preferably 90 mass % or more.

[0047] The back primer layer contains a pigment. Examples of pigments include metal oxides such as titanium dioxide, zinc oxide, cerium oxide, aluminum oxide, and finely powdered silica; metal pigments such as aluminum powder, gold powder, silver powder, copper powder, bronze powder, zinc powder, stainless steel powder, and nickel powder; titanium mica, calcium carbonate, barium sulfate, alumina white, talc, and kaolin; inorganic pigments such as pearl pigments; and organic pigments such as chromatic pigments. The back primer layer can contain one or more types of pigments.

[0048] In one embodiment, the back primer layer contains one or more white pigments as the pigment. Examples of the white pigment include titanium dioxide, zinc oxide, finely powdered silica, calcium carbonate, barium sulfate, alumina white, and kaolin. In this embodiment, the concealment of the base can be further improved.

[0049] The back primer layer may contain additives. Examples of additives include plasticizers, coloring inhibitors, surfactants, fluorescent whitening agents, matting agents, deodorants, flame retardants, antistatic agents, friction reducers, slip agents, dispersants, UV absorbers, antioxidants, weather stabilizers, and dyes. The back primer layer may contain one or more additives.

[0050] In one embodiment, the back primer layer contains one or more fluorescent brighteners, such as thiophene-based fluorescent brighteners such as 2,5-bis(5-t-butyl-2-benzoxazolyl)thiophene and 2,5-bis(benzoxazol-2-yl)thiophene, coumarin-based fluorescent brighteners, stilbene-based fluorescent brighteners, naphthalene-based fluorescent brighteners, and benzimidazole-based fluorescent brighteners.

[0051] The mass ratio of the pigment content to the resin material content in the back primer layer (pigment content / resin material content, hereinafter also referred to as "PV ratio") is 1.00 or more and 3.00 or less, preferably 1.30 or more and 2.50 or less. If the PV ratio exceeds 3.00, the back surface of the thermal transfer image receiving sheet is easily scratched during transportation during printing, the writability of the back surface tends to decrease, and double feeding of the thermal transfer image receiving sheet tends to occur. If the PV ratio is less than 1.00, when the back primer layer contains a white pigment such as titanium dioxide, the hiding power tends to decrease. If the PV ratio is within the above range, a thermal transfer image receiving sheet excellent in transportability during printing, suppression of scratches during transportation, back writability, and hiding power can be obtained.

[0052] The thickness of the back primer layer is 0.20 μm or more and 0.90 μm or less, preferably 0.30 μm or more and 0.80 μm or less. If the thickness exceeds 0.90 μm, double feeding of the thermal transfer image receiving sheet tends to occur during transportation during printing. If the thickness is less than 0.20 μm, the back surface of the thermal transfer image receiving sheet is easily scratched during transportation during printing, and the writability of the back surface tends to decrease, and if the back primer layer contains a white pigment such as titanium dioxide, the hiding property tends to decrease. If the thickness is within the above range, a thermal transfer image receiving sheet excellent in transportability during printing, suppression of scratches during transportation, back writability, and hiding property can be obtained.

[0053] The thickness of the back primer layer can be measured from a photograph of a cross section of the thermal transfer image receiving sheet in the thickness direction observed with a scanning electron microscope (SEM) or a photograph observed with an energy dispersive X-ray spectroscopy of an SEM (SEM-EDX). The same applies to the thicknesses of the other layers.

[0054] The back primer layer can be formed, for example, by dispersing or dissolving the above-mentioned materials in water or a suitable organic solvent to prepare a coating liquid, applying the coating liquid onto a substrate by the above-mentioned known coating means to form a coating film, and drying the coating film.

[0055] <Thermal insulation layer> In one embodiment, the thermal transfer image receiving sheet of the present disclosure includes a heat insulating layer. The heat insulating layer is provided, for example, between the substrate and the receiving layer. The heat insulating layer has heat insulating properties that suppress the loss of heat applied during image formation by thermal transfer due to heat transfer to the substrate or the like.

[0056] Examples of the heat insulating layer include a hollow particle-containing layer that contains hollow particles and a porous film having fine voids therein. The heat insulating layer may include two or more hollow particle-containing layers, two or more porous films, or a hollow particle-containing layer and a porous film.

[0057] The hollow particle-containing layer contains hollow particles. By containing hollow particles, the hollow particle-containing layer has heat insulation properties that suppress the loss of heat applied during image formation by thermal transfer due to heat transfer to a substrate or the like, and also has cushioning properties.

[0058] The hollow particles may be organic hollow particles, inorganic hollow particles, or organic-inorganic composite hollow particles. From the viewpoint of dispersibility in the resin material, however, organic hollow particles and organic-inorganic composite hollow particles are preferred.

[0059] The hollow particles may be expandable particles or non-expandable particles. The hollow particles may be particles consisting of a shell and a gas contained within the shell, or may be particles consisting of a shell and a liquid such as liquid hydrocarbon contained within the shell.

[0060] The organic hollow particles have a shell made of a resin material, such as (meth)acrylonitrile resins such as (meth)acrylonitrile copolymers, styrene resins such as polystyrene and crosslinked styrene-(meth)acrylic resins, vinyl resins such as polyvinylidene chloride, (meth)acrylic resins such as polymethyl(meth)acrylate, phenol resins, fluororesins, imide resins, and polycarbonates.

[0061] In one embodiment, the organic hollow particles can be produced by encapsulating a foaming agent such as butane gas in resin particles and heating and foaming them. In one embodiment, the organic hollow particles can be produced by utilizing emulsion polymerization. Commercially available organic hollow particles may be used.

[0062] Examples of the organic-inorganic composite hollow particles include hollow particles in which the shell surface of an organic hollow particle is modified with an inorganic material such as an inorganic powder. Examples of the organic hollow particles include the organic hollow particles exemplified above. Examples of the inorganic material include talc, calcium carbonate, silica, titania, and alumina. In one embodiment, the organic-inorganic composite hollow particles are hollow particles in which the surface of a polyacrylonitrile-based hollow particle such as an acrylonitrile-based copolymer is modified with talc. Commercially available organic-inorganic composite hollow particles may be used.

[0063] Examples of inorganic hollow particles include hollow silica particles, hollow glass particles, and hollow ceramic particles.

[0064] The average particle diameter of the hollow particles is preferably 0.1 μm to 30 μm, more preferably 0.5 μm to 30 μm, and even more preferably 1 μm to 25 μm. The average particle diameter of the hollow particles is measured by an electron microscope. Specifically, a cross-sectional image of the cross section of the hollow particle-containing layer is obtained by a scanning electron microscope, and the particle diameter is obtained as the average value of the major axis diameter and the minor axis diameter of each particle in the cross-sectional image, and the arithmetic average of the particle diameters of 100 particles is taken as the average particle diameter. The hollow particle-containing layer can contain one or more types of hollow particles.

[0065] The content of hollow particles in the hollow particle-containing layer is preferably 5% by mass or more and 70% by mass or less, more preferably 15% by mass or more and 60% by mass or less, and even more preferably 30% by mass or more and 55% by mass or less.

[0066] The hollow particle-containing layer contains a resin material. Examples of resin materials include urethane resin, (meth)acrylic resin, polyester, urethane-modified polyester, polycarbonate, polyamide, styrene resin, vinyl resin, polyolefin, gelatin and its derivatives, polyvinyl alcohol, polyvinylpyrrolidone, pullulan, carboxymethyl cellulose, hydroxyethyl cellulose, dextran, dextrin, poly(meth)acrylic acid and its salts, agar, κ-carrageenan, λ-carrageenan, ι-carrageenan, casein, xanthan gum, locust bean gum, alginic acid, and gum arabic. The hollow particle-containing layer can contain one or more types of resin materials.

[0067] The content of the resin material in the hollow particle-containing layer is preferably 30% by mass or more and 95% by mass or less, more preferably 40% by mass or more and 85% by mass or less, and further preferably 45% by mass or more and 70% by mass or less.

[0068] The hollow particle-containing layer may contain additives. Examples of additives include plasticizers, coloring inhibitors, surfactants, fluorescent whitening agents, matting agents, deodorants, flame retardants, antistatic agents, friction reducers, slip agents, dispersants, UV absorbers, antioxidants, weather stabilizers, fillers, and colorants such as pigments and dyes. The hollow particle-containing layer may contain one or more additives.

[0069] The thickness of the hollow particle-containing layer is preferably from 5 μm to 100 μm, more preferably from 12 μm to 80 μm, further preferably from 18 μm to 60 μm, and particularly preferably from 20 μm to 50 μm.

[0070] The hollow particle-containing layer can be formed, for example, by preparing a coating liquid by dispersing or dissolving the above-mentioned materials in water or an appropriate organic solvent, applying the coating liquid to a substrate or the like by the above-mentioned known coating means to form a coating film, and drying the coating film.

[0071] Examples of resin materials constituting the porous film include polyolefins such as polyethylene and polypropylene, vinyl resins such as polyvinyl acetate, vinyl chloride-vinyl acetate copolymer and ethylene-vinyl acetate copolymer, polyesters such as polyethylene terephthalate and polybutylene terephthalate, styrene resins, and polyamides. The porous film can contain one or more types of resin materials.

[0072] The porous film can contain one or more of the above additives.

[0073] The thickness of the porous film is preferably 20 μm or more and 150 μm or less, and more preferably 30 μm or more and 130 μm or less.

[0074] The porous film can be produced by a known method. For example, the porous film can be produced by forming a mixture of the above-mentioned resin material and incompatible organic or inorganic particles into a film, and stretching the film as necessary. For example, the porous film can be produced by forming a mixture of polypropylene and polyester or (meth)acrylic resin having a melting point higher than that of polypropylene into a film, and stretching the film as necessary. The polyester or (meth)acrylic resin serves as a nucleating agent that forms fine voids. The porous film is not limited to the porous film produced by the above-mentioned method, and a commercially available porous film may be used.

[0075] The porous film can be laminated on the substrate via an adhesive layer, for example. A plurality of porous films may be laminated on the substrate via adhesive layers.

[0076] <Receptive layer> The thermal transfer image receiving sheet of the present disclosure includes a receiving layer, which is a layer that receives a sublimation dye transferred from a sublimation transfer color material layer (dye layer) included in the thermal transfer sheet, and maintains the formed image.

[0077] In one embodiment, the receiving layer contains a resin material. The resin material is not limited as long as it is a resin that is easily dyed with a dye, and examples thereof include polyolefins; vinyl resins such as polyvinyl chloride, polyvinyl acetate, vinyl chloride-vinyl acetate copolymers, and ethylene-vinyl acetate copolymers; polyvinyl acetal resins such as polyvinyl butyral resins and polyvinyl acetoacetal resins; styrene resins, (meth)acrylic resins, polyesters, polyamides, polycarbonates, urethane resins, cellulose resins, and ionomer resins. The receiving layer can contain one or more types of resin materials.

[0078] The content of the resin material in the receiving layer is preferably 70% by mass or more and 99% by mass or less, more preferably 80% by mass or more and 98% by mass or less, and even more preferably 90% by mass or more and 97% by mass or less.

[0079] In one embodiment, the receiving layer contains a release agent. This can improve the releasability between the thermal transfer image receiving sheet and the thermal transfer sheet, for example. Examples of the release agent include solid waxes such as polyethylene wax, amide wax, and Teflon (registered trademark) powder; fluorine-based or phosphate-based surfactants; silicone oils, and silicone resins.

[0080] The silicone oil is preferably a modified silicone oil such as a reactive silicone oil or a cured silicone oil. The modified silicone oil is preferably an amino-modified silicone, an epoxy-modified silicone, an aralkyl-modified silicone, an epoxy-aralkyl-modified silicone, an alcohol-modified silicone, a vinyl-modified silicone, or a urethane-modified silicone, and examples of the modified silicone oil include an amino-modified silicone, an epoxy-modified silicone, an aralkyl-modified silicone, and an epoxy-aralkyl-modified silicone. The receiving layer may contain one or more release agents.

[0081] The content of the release agent in the receiving layer is preferably 0.5% by mass to 20% by mass, more preferably 0.5% by mass to 10% by mass, which can improve the releasability between the thermal transfer image receiving sheet and the thermal transfer sheet while maintaining the transparency of the receiving layer, for example.

[0082] The receiving layer may contain one or more of the above additives. For example, from the viewpoint of improving the whiteness of the receiving layer and further enhancing the sharpness of the thermally transferred image, the receiving layer may contain a white pigment.

[0083] The thickness of the receiving layer is preferably 0.5 μm or more and 20 μm or less, and more preferably 1 μm or more and 10 μm or less, which can, for example, further improve the density of the image formed on the receiving layer.

[0084] The receiving layer can be formed, for example, by dispersing or dissolving the above-mentioned materials in water or a suitable organic solvent to prepare a coating liquid, applying the coating liquid onto any layer by the known coating means described above to form a coating film, and drying the coating film.

[0085] <Adhesive layer> In one embodiment, the thermal transfer image receiving sheet of the present disclosure has an adhesive layer between any layers (for example, between the substrate and the heat insulating layer, between each layer in the laminated substrate, and between each layer constituting the heat insulating layer having a multi-layer structure). This can improve the adhesion between the layers.

[0086] In one embodiment, the adhesive layer contains a resin material. Examples of the resin material include vinyl resins such as polyvinyl acetate, polyvinyl chloride, ethylene-vinyl acetate copolymer, and vinyl chloride-vinyl acetate copolymer, polyolefin, polyester, (meth)acrylic resin, polyol resin, and urethane resin. The adhesive layer can contain one or more types of resin materials.

[0087] The adhesive layer may contain one or more of the above additives. The thickness of the adhesive layer is, for example, not less than 0.5 μm and not more than 10 μm.

[0088] The adhesive layer can be formed, for example, by dispersing or dissolving the above-mentioned materials in water or a suitable organic solvent to prepare a coating liquid, applying the coating liquid onto any layer by the above-mentioned known coating means to form a coating film, and drying the coating film. In one embodiment, the adhesive layer can be formed by melt-extruding a resin composition containing the above-mentioned materials.

[0089] The adhesive layer can also be formed using a conventionally known adhesive. The adhesive may be any one of a one-component curing type, a two-component curing type, and a non-curing type. The adhesive may be a solventless adhesive or a solvent-based adhesive. The adhesive layer may be formed, for example, by a non-solvent lamination method or a dry lamination method.

[0090] Examples of adhesives include two-component curing urethane adhesives, polyester-based polyurethane adhesives, polyether-based polyurethane adhesives, (meth)acrylic adhesives, polyester-based adhesives, polyether-based adhesives, polyamide-based adhesives, epoxy-based adhesives, rubber-based adhesives, polyolefin-based adhesives, acid-modified polyolefin-based adhesives, polyvinyl acetate-based adhesives, and polyvinyl chloride-based adhesives.

[0091] <Primer layer> In one embodiment, the thermal transfer image receiving sheet of the present disclosure includes a primer layer between the substrate or the heat insulating layer and the receiving layer, which can improve the adhesion between these layers.

[0092] In one embodiment, the primer layer contains a resin material. Examples of the resin material include polyester, polyamide, polycarbonate, urethane resin, polyolefin, (meth)acrylic resin, styrene resin, vinyl resin (e.g., polyvinyl chloride, polyvinyl acetate, vinyl chloride-vinyl acetate copolymer, ethylene-vinyl acetate copolymer, and polyvinyl alcohol), polyvinyl acetal resin (e.g., polyvinyl butyral resin and polyvinyl acetoacetal resin), and cellulose resin. The primer layer can contain one or more types of resin materials.

[0093] Among the above resin materials, for the resin materials having active hydroxyl groups, the isocyanate cured product of the resin material can be used as the binder. Examples of isocyanate compounds that can be used in this case include the polyisocyanates described above as raw materials for the urethane resin.

[0094] The primer layer may contain one or more of the above additives. The thickness of the primer layer is, for example, not less than 0.1 μm and not more than 3 μm.

[0095] The primer layer can be formed, for example, by dispersing or dissolving the above-mentioned materials in water or a suitable organic solvent to prepare a coating liquid, applying the coating liquid to a substrate or a heat insulating layer, etc. by the known coating means described above to form a coating film, and drying the coating film.

[0096] [Printed matter] The print of the present disclosure is produced using the thermal transfer image receiving sheet, and includes a back layer, a back primer layer, a substrate, and a receiving layer on which an image is formed. The details of each layer are as described above.

[0097] The image formed on the receiving layer is not particularly limited and may be a letter, a pattern, a symbol, a combination thereof, etc. The image can be formed on the receiving layer by using a thermal transfer sheet for a conventionally known dye-sublimation type thermal transfer recording method or a melting type thermal transfer recording method, for example.

[0098] <Protective layer> In one embodiment, the printed matter of the present disclosure includes a protective layer on a receiving layer on which an image is formed. The printed matter 2 of one embodiment shown in Fig. 3 includes a back layer 14, a back primer layer 12, a substrate 10, a receiving layer 20 on which an image (not shown) is formed, and a protective layer 22 in this order in the thickness direction. The printed matter 2 of one embodiment shown in Fig. 4 includes a back layer 14, a back primer layer 12, a substrate 10, a heat insulating layer 16, a primer layer 18, a receiving layer 20 on which an image (not shown) is formed, and a protective layer 22 in this order in the thickness direction.

[0099] In one embodiment, the protective layer contains a resin material. The resin material is not particularly limited as long as it has transparency. Examples of the resin material include (meth)acrylic resin, styrene resin, vinyl resin, polyolefin, polyester, polyamide, cellulose resin, cured product of thermosetting resin, and cured product of active energy ray curable resin. The protective layer can contain one or more types of resin materials.

[0100] Examples of the thermosetting resin include epoxy resins, melamine resins, guanamine resins, urea resins, unsaturated polyesters, thermosetting urethane resins, thermosetting (meth)acrylic resins, and aminoalkyd resins.

[0101] The active energy ray curable resin is a resin that is cured by irradiation with active energy rays. Examples of the active energy rays include electromagnetic waves such as ultraviolet rays (UV), X-rays, and gamma rays; and charged particle rays such as electron beams (EB), alpha rays, and ion rays. Examples of the active energy ray curable resin include polyfunctional (meth)acrylate monomers and polyfunctional (meth)acrylate oligomers.

[0102] The content of the resin material in the protective layer is preferably 50% by mass or more, more preferably 50% by mass or more and 95% by mass or less, which can improve, for example, the scratch resistance and storage stability of the image formed on the receiving layer. The protective layer may contain one or more of the above additives.

[0103] The thickness of the protective layer is preferably from 0.1 μm to 10 μm, more preferably from 0.5 μm to 5 μm, which can improve, for example, the scratch resistance and storage stability of the image formed on the receiving layer.

[0104] [Manufacturing method of printed matter] The method for producing a print of the present disclosure includes (1) a step of preparing the thermal transfer image receiving sheet of the present disclosure, and (2) a step of forming an image on a receiving layer of the thermal transfer image receiving sheet (image forming step). In one embodiment, the method for producing a print of the present disclosure includes (3) a step of forming a protective layer on the receiving layer on which the image is formed (protective layer forming step). The structure of the thermal transfer image receiving sheet has been described above, and therefore will not be described here.

[0105] Examples of the image forming method include a method using a thermal transfer sheet of a conventionally known sublimation type thermal transfer recording method or a melting type thermal transfer recording method. In the sublimation type thermal transfer recording method, a thermal transfer sheet having a sublimation transfer type color material layer containing a sublimation dye is used to transfer the sublimation dye to a receiving layer to form an image. In the melting type thermal transfer recording method, a thermal transfer sheet having a melting transfer type color material layer is used to transfer the melting transfer type color material layer onto a receiving layer to form an image. In addition, an image may be formed by combining these methods.

[0106] The protective layer can be formed by a conventional method, for example, by transferring a protective layer from a protective layer transfer sheet having a protective layer onto a receiving layer on which an image is formed. The protective layer may be formed by laminating a film for forming a protective layer onto the receiving layer via an adhesive layer or the like. Details of the protective layer are as described above. The protective layer transfer sheet may be a thermal transfer sheet having a protective layer in surface order with the color material layer.

[0107] Specifically, the image is formed by superimposing the thermal transfer sheet and the thermal transfer image receiving sheet of the present disclosure and applying heat from the back side of the thermal transfer sheet using a heating member such as a thermal head to transfer the sublimation dye contained in the sublimation transfer colorant layer to the receiving layer, or by transferring the melt transfer colorant layer onto the receiving layer.

[0108] Specifically, the protective layer is formed by superposing a thermal transfer image receiving sheet having an image formed on a receiving layer and the protective layer transfer sheet, and applying heat from the back side of the protective layer transfer sheet using a heating member such as a thermal head to transfer the protective layer onto the receiving layer.

[0109] The present disclosure relates to, for example, the following [1] to [9]. [1] A thermal transfer image receiving sheet comprising a back layer, a back primer layer, a substrate, and a receiving layer in this order, wherein the back primer layer contains a pigment and a resin material including a urethane resin component, the mass ratio of the pigment content to the resin material content in the back primer layer (pigment content / resin material content) is 1.00 or more and 3.00 or less, and the thickness of the back primer layer is 0.20 μm or more and 0.90 μm or less. [2] The thermal transfer image receiving sheet according to the above [1], wherein the thickness of the back layer is from 0.05 μm to 2.00 μm. [3] The thermal transfer image receiving sheet according to the above [1] or [2], wherein the urethane resin component is at least one selected from the group consisting of urethane resins and urethane resins crosslinked with an isocyanate-based crosslinking agent. [4] The thermal transfer image-receiving sheet according to the above [3], wherein the urethane resin has a softening point of 80°C or higher and 100°C or lower. [5] The thermal transfer image receiving sheet according to the above [3] or [4], wherein the urethane resin has a glass transition temperature of -28°C or higher and 5°C or lower. [6] A method for producing a printed matter, comprising: (1) a step of preparing a thermal transfer image receiving sheet described in any one of [1] to [5] above; and (2) a step of forming an image on a receiving layer provided in the thermal transfer image receiving sheet. [7](3) A method for producing a printed matter according to the above [6], further comprising the step of forming a protective layer on the receiving layer on which the image has been formed. [8] A printed matter comprising the thermal transfer image receiving sheet according to any one of the above [1] to [5] and an image formed on a receiving layer of the thermal transfer image receiving sheet. [9] The print according to [8] above, further comprising a protective layer on the receiving layer on which the image is formed. EXAMPLES

[0110] The thermal transfer image receiving sheet and the like of the present disclosure will be described in more detail below based on examples, but the thermal transfer image receiving sheet and the like of the present disclosure are not limited to these examples. In the following description, "parts" means "parts by mass."

[0111] [Preparation of coating solution for back primer layer] A coating solution (1) for a back surface primer layer having the following composition was prepared. Urethane resin 10.7 parts (solid content 3.20 parts) (Nippolan (registered trademark) 5253, solid content 30% by mass, Tosoh Corporation) Titanium dioxide 6.40 parts (TCA-888, Tochem Products Co., Ltd.) Fluorescent whitening agent 0.06 parts (2,5-Bis(5'-t-butylbenzoxazolyl-2')thiophene, Doubletex OB, DOUBLE BOND CHEMICAL IND. CO., LTD.) Polyisocyanate compound 0.48 parts (Coronate (registered trademark) HX, an isocyanurate of hexamethylene diisocyanate, Tosoh Corporation) Methyl ethyl ketone 20.2 parts

[0112] Coating solutions (2) to (5) for the back primer layer were prepared in the same manner as for Coating Solution (1) for the back primer layer, except that the solid content ratio of each component was changed as shown in Table 1.

[0113] [Table 1]

[0114] [Example 1] A polypropylene film with internal voids (microvoids) (product name: #35 SP-U, Mitsui Chemicals Tohcello Co., Ltd.) was applied to one side of a coated paper (product name: NeostarGloss180, Moorim P&P Co., Ltd.) with a coating solution for adhesive layer of the following composition (coating amount: 2.5 g / m 2 (After drying)) was used to laminate the sheets together to obtain a polypropylene film / adhesive layer / coated paper.

[0115] Next, a 25 μm thick PET film (product name: Lumirror (registered trademark) T-60, Toray Industries, Inc.) was applied to the other side of the coated paper using a coating solution for the adhesive layer having the following composition (coating amount: 2.5 g / m 2 (After drying)) was used to laminate the sheets together to obtain a polypropylene film / adhesive layer / coated paper / adhesive layer / PET film.

[0116] Next, a primer layer coating liquid having the following composition was applied to the surface of the polypropylene film and dried to form a primer layer having a thickness of 1.5 μm. A receiving layer coating liquid having the following composition was applied to the primer layer and dried to form a receiving layer having a thickness of 4 μm. The back primer layer coating liquid (1) was applied to the surface of the PET film and dried at 100° C. for 1 minute to form a back primer layer having a thickness of 0.40 μm. A back layer coating liquid having the following composition was applied to the back primer layer and dried at 100° C. for 1 minute to form a back layer having a thickness of 0.19 μm.

[0117] In this way, a thermal transfer image-receiving sheet was obtained, which had a layer structure of receptor layer / primer layer / polypropylene film / adhesive layer / coated paper / adhesive layer / PET film / reverse primer layer / reverse layer.

[0118] <Coating liquid for adhesive layer> · Urethane resin 30 parts (Takelac® A-969V, Mitsui Chemicals, Inc.) Isocyanate 10 parts (Takenate (registered trademark) A-5, Mitsui Chemicals, Inc.) 60 parts ethyl acetate

[0119] <Coating fluid for primer layer> Polyester 4.2 parts (Nichigo Polyester (registered trademark) WR-905, Mitsubishi Chemical Corporation) Titanium dioxide 8.4 parts (TCA-888, Tochem Products Co., Ltd.) Fluorescent whitening agent 0.07 parts (Ubitex®BAC, BASF Japan) 7.2 parts isopropyl alcohol ·Wednesday 21 parts

[0120] <Coating solution for receiving layer> Vinyl chloride-vinyl acetate copolymer 12 parts (Solvine (registered trademark) C, Nissin Chemical Industry Co., Ltd.) Epoxy modified silicone 0.8 parts (X-22-3000T, Shin-Etsu Chemical Co., Ltd.) Amino modified silicone 0.24 parts (X-22-1660B-3, Shin-Etsu Chemical Co., Ltd.) Toluene 30 parts Methyl ethyl ketone 30 parts

[0121] <Coating fluid for back layer> Polyvinyl butyral 10 parts (S-LEC (registered trademark) BL-7, Sekisui Chemical Co., Ltd.) Silicon dioxide 0.75 parts (Silysia 380, Fuji Silysia Chemical Co., Ltd.) Titanium chelate compound 0.117 parts (AT chelating agent, Denka Polymer Co., Ltd.) Toluene 40 parts Methyl ethyl ketone 40 parts

[0122] [Examples 2 to 8, Comparative Examples 1 to 5] A thermal transfer image receiving sheet was prepared in the same manner as in Example 1, except that at least one of the type of resin film constituting the laminated substrate, the type of coating liquid for the back primer layer, the thickness and PV ratio of the back primer layer, and the thickness of the back layer was changed as shown in Table 2.

[0123] The substrates (resin films) listed in Table 2 are as follows. PET: Polyethylene terephthalate film (Lumirror (registered trademark) T-60, thickness 25 μm, Toray Industries, Inc.) OPP: Biaxially oriented polypropylene film (PA30, thickness 30μm, Sun Tox Co., Ltd.)

[0124] [Evaluation of thermal transfer image receiving sheets] The thermal transfer image-receiving sheets prepared in the Examples and Comparative Examples were evaluated as follows. <Abrasion resistance> With reference to the drying test of JIS L0849, the abrasion resistance of the back layer of the thermal transfer image receiving sheet was tested under the following measurement conditions using an "Friction Tester FR-II" (Suga Test Instruments Co., Ltd., a Gakushin-type abrasion fastness tester specified in JIS L0849) and the sample was visually inspected for scratches after the test. (Measurement conditions) Sample size: 220mm x 30mm Load capacity: 200g Friction speed: 30 strokes per minute Number of friction strokes: 20 strokes or 100 strokes (Judgment criteria) A: No scratches were found after 100 round trips. B: No scratches were found after 20 round trips, but scratches were found after 100 round trips. C: Scratches were found after 20 round trips, causing problems in practical use.

[0125] <Double feeding and backside transport scratches> Using a dye-sublimation thermal transfer printer (manufactured by Xiaomi Inc., model: Xiaomi MIJIA Photo Printer), 20 black solid images were printed on the thermal transfer image receiving sheet to obtain prints.

[0126] The occurrence of double feeding during printing was evaluated according to the following criteria. (Judgment criteria) · Good: The thermal transfer image receiving sheets (printed materials) were not transported overlapping each other and were discharged well. ×: The thermal transfer image receiving sheets (printed matter) were discharged overlapping each other.

[0127] The back surface layer of the printed matter was visually inspected for scratches caused during transportation. · 〇: No damage was found during transportation. ×: Damage caused during transportation was confirmed.

[0128] <Writability on the back side> Writing was done on the back surface of the thermal transfer image receiving sheet with a water-based ballpoint pen, and after one minute, the back surface was rubbed with Bencotton and visually inspected to see whether the written characters had faded or not. · Good: The letters did not fade when rubbed with Bencotton. ×: The letters became faint when rubbed with Bencotton.

[0129] <Concealment> The defects of the coated paper and the back side substrate were visually confirmed from the back side of the thermal transfer image receiving sheet. Here, the defects refer to foreign matter, fish eyes, etc. that are thought to have occurred during the production of the coated paper and the back side substrate. If no defects were found, it can be said that the concealment by the back primer layer is high. (Judgment criteria) A: No defects were identified. B: Defects were identified, but they were minor and did not pose a problem in practical use. C: Defects were identified and problems occurred in practical use.

[0130] The results of each of the above evaluations are shown in Table 2.

[0131] [Table 2] [Explanation of symbols]

[0132] 1: Thermal transfer image receiving sheet 10: Base material 12: Back primer layer 14: Back layer 16: Insulation layer 18: Primer layer 20: Receptive layer 2: Prints 22:Protective layer

Claims

1. A thermal transfer image receiving sheet comprising a back surface layer, a back surface primer layer, a substrate, and a receiving layer in this order, the back surface primer layer contains a pigment and a resin material containing a urethane resin component, a mass ratio of the pigment content to the resin material content in the back primer layer (pigment content / resin material content) is 1.00 or more and 3.00 or less; The thickness of the back primer layer is 0.20 μm or more and 0.90 μm or less. Thermal transfer image receiving sheet.

2. 2. The thermal transfer image receiving sheet according to claim 1, wherein the thickness of the back surface layer is from 0.05 [mu]m to 2.00 [mu]m.

3. 3. The thermal transfer image receiving sheet according to claim 1, wherein the urethane resin component is at least one selected from the group consisting of a urethane resin and a crosslinked product of the urethane resin with an isocyanate-based crosslinking agent.

4. 4. The thermal transfer image-receiving sheet according to claim 3, wherein the urethane resin has a softening point of 80°C or higher and 100°C or lower.

5. 5. The thermal transfer image-receiving sheet according to claim 3, wherein the urethane resin has a glass transition temperature of -28°C or higher and 5°C or lower.

6. (1) preparing a thermal transfer image receiving sheet according to any one of claims 1 to 5; (2) forming an image on the receiving layer of the thermal transfer image receiving sheet; A method for producing a printed matter comprising the steps of:

7. (3) A step of forming a protective layer on the receiving layer on which the image is formed. The method for producing a print according to claim 6 , further comprising:

8. A thermal transfer image receiving sheet according to any one of claims 1 to 5, An image formed on the receiving layer of the thermal transfer image receiving sheet; A printed matter that has the above features.

9. The print according to claim 8 , further comprising a protective layer on the receiving layer on which the image is formed.

Images