Print and protective layer transfer sheet

Abstract

To prevent generation of abnormal noise when image forming surfaces of printed matters are rubbed with each other.SOLUTION: The printed material of the present disclosure includes a base material sheet 1, receiving layers 2 and 3 provided on both surfaces of the base material sheet 1 and having thermal transfer images 4 and 5 formed thereon, and protective layers 6 and 7 provided so as to cover the receiving layers 2 and 3 on both surfaces of the base material sheet 1. When a vertical load (point pressure of 200g) is applied using a ball indenter and the ball indenter is slid on the sample surfaces at a speed of 500mm / min under the condition that the protective layer-side of one of the two printed matters and the protective layer-side of the other printed matter are in contact with each other based on the method of JISK7125:1999, the absolute difference between the maximum and minimum dynamic friction coefficients measured is 0.45 or less.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a print and a protective layer transfer sheet. [Background technology]

[0002] Various thermal transfer recording methods have been known, including a sublimation thermal transfer method in which a dye in a sublimation dye layer on a thermal transfer sheet is transferred to a thermal transfer image-receiving sheet using a heating device such as a thermal head or laser beam, the heat generation of which is controlled according to image information, to form an image. Since the coloring material used in the sublimation thermal transfer method is a sublimation dye, the image is very clear and has excellent transparency, and therefore has excellent half-tone reproducibility and gradation, allowing for the production of extremely high-definition images.

[0003] One application of dye-sublimation thermal transfer technology is a thermal transfer image-receiving sheet that can be printed on both sides. Thermal transfer image-receiving sheets that can be printed on both sides not only reduce the number of sheets required and save resources, but are also suitable for producing booklet-shaped color prints such as photo books, and for producing postcards and various cards. Therefore, several proposals have been made for thermal transfer image-receiving sheets that can be printed on both sides.

[0004] For example, Patent Document 1 discloses a thermal transfer image receiving sheet in which dye receiving layers are formed on both sides of a base sheet and both dye receiving layers are matte. However, such thermal transfer image receiving sheets have a problem in that when overlapping thermal transfer image receiving sheets are rubbed against each other, an abnormal noise is generated, which is annoying and upsetting to people handling them.

[0005] Patent Document 2 describes that when a plurality of printed materials are stacked together by forming thermal transfer images on the dye receiving layers on both sides of a thermal transfer image receiving sheet and forming protective layers to cover the thermal transfer images on both sides, the generation of abnormal noise can be prevented by setting the dynamic friction coefficient between the front and back surfaces of the printed materials to 1.1 or less. However, it was difficult to sufficiently suppress the generation of abnormal noise by simply setting the dynamic friction coefficient to 1.1 or less. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 5-229265 [Patent Document 2] Japanese Patent Application Laid-Open No. 2011-5645 Summary of the Invention [Problem to be solved by the invention]

[0007] An object of the present disclosure is to provide a printed matter and a protective layer transfer sheet that can prevent abnormal noises from being generated when image-forming surfaces are rubbed against each other. [Means for solving the problem]

[0008] [1] A base sheet; a receiving layer provided on each side of the substrate sheet and having a thermal transfer image formed thereon; protective layers provided so as to cover the receiving layers on both sides of the base sheet; A print comprising: A printed material in which the absolute value of the difference between the maximum and minimum values ​​of the dynamic friction coefficient measured is 0.45 or less when a ball indenter is used to apply a vertical load (point pressure of 200g) and slide the ball indenter across the sample surface at a speed of 500mm / min, under the condition that the surface with the protective layer of one of the two printed materials is in contact with the surface with the protective layer of the other printed material, based on the method of JIS K 7125:1999. The coefficient of friction is the value obtained by dividing the measured tension (unit: N) by a load of 1.96N.

[0009] [2] The printed matter according to [1], wherein the coefficient of dynamic friction is 0.9 or less.

[0010] [3] The printed matter according to [1] or [2], wherein the outermost layer contains an aralkyl-modified silicone oil or a long-chain alkyl-modified silicone oil.

[0011] [4] The printed matter according to any one of [1] to [3], wherein the outermost layer contains silica particles.

[0012] [5] The printed matter according to any one of [1] to [4], wherein the outermost layer contains a styrene-acrylic resin.

[0013] [6] A base sheet; a receiving layer provided on one surface of the base sheet and having a thermal transfer image formed thereon; a protective layer provided to cover the receiving layer; A print comprising: A printed material in which, based on the method of JIS K 7125:1999, the printed material is folded so that the surface on which the thermal transfer image is formed is on the inside, and the opposing surfaces are in contact, and a vertical load (point pressure of 200 g) is applied using a ball indenter, and the ball indenter is slid across the sample surface at a speed of 500 mm / min, and the absolute value of the difference between the maximum and minimum values ​​of the measured dynamic friction coefficient is 0.45 or less. The coefficient of friction is the value obtained by dividing the measured tension (unit: N) by a load of 1.96N.

[0014] [7] A protective layer transfer sheet having a release layer and an adhesive layer laminated in this order on one surface of a substrate, The protective layer transfer sheet, wherein the release layer contains a styrene-acrylic resin and at least one of silicone oil and polyethylene wax.

[0015] [8] The protective layer transfer sheet according to [7], wherein the silicone oil is an aralkyl-modified silicone oil or a long-chain alkyl-modified silicone oil. [Effects of the Invention]

[0016] According to the present disclosure, it is possible to prevent abnormal noises from being generated when the image-forming surfaces of printed materials are rubbed against each other. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is a cross-sectional view of a print according to an embodiment of the present disclosure. [Figure 2] FIG. 1 is a cross-sectional view of a print according to an embodiment of the present disclosure. [Figure 3] FIG. 1 is a cross-sectional view of a print according to an embodiment of the present disclosure. [Figure 4] FIG. 1 is a cross-sectional view of a print according to an embodiment of the present disclosure. [Figure 5] FIG. 1 is a cross-sectional view of a protective layer transfer sheet according to an embodiment of the present disclosure. [Figure 6] FIG. 10 is a diagram showing an example of a measurement chart of friction force. [Figure 7] FIG. 10 is a diagram showing an example of a measurement chart of friction force. DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings, etc. Note that the present disclosure can be implemented in many different forms, and should not be construed as being limited to the description of the embodiments exemplified below. Furthermore, to clarify the explanation, the drawings may show the width, thickness, etc. of each part more schematically than in the actual form, but these are merely examples and do not limit the interpretation of the present disclosure.

[0019] As shown in Figure 1, the printed matter according to an embodiment of the present disclosure comprises a base sheet 1, a receiving layer 2 provided on one side of the base sheet 1 and having a thermal transfer image 4 formed thereon, a receiving layer 3 provided on the other side of the base sheet 1 and having a thermal transfer image 5 formed thereon, a protective layer 6 provided on the entire front side of the printed matter so as to cover the thermal transfer image 4, and a protective layer 7 provided on the entire back side of the printed matter so as to cover the thermal transfer image 5.

[0020] As shown in Figure 2, the base sheet 1 can be configured by laminating a porous film 11 on one side of a core material 10 via an adhesive layer 13, and laminating a porous film 12 on the other side of the core material 10 via an adhesive layer 14.

[0021] An intermediate layer 8 may be provided between the base sheet 1 and the receiving layer 2. Similarly, an intermediate layer 9 may be provided between the base sheet 1 and the receiving layer 3.

[0022] Protective layer 6 may have a two-layer structure having an adhesive layer 15 and a release layer 17 laminated in this order from the receiving layer 2 side. Similarly, protective layer 7 may have a two-layer structure having an adhesive layer 16 and a release layer 18 laminated in this order from the receiving layer 3 side. In the printed matter shown in Figure 1, protective layers 6 and 7 are the outermost layers, and in the printed matter shown in Figure 2, release layers 17 and 18 are the outermost layers.

[0023] To produce this print, first prepare a thermal transfer image-receiving sheet having receiving layers 2 and 3 on both sides of a substrate sheet 1, and a thermal transfer sheet having a dye layer containing a sublimation dye. Then, the thermal transfer sheet is heated using a thermal head or the like, and the sublimation dye is thermally transferred to the receiving layers 2 and 3 to form thermal transfer images 4 and 5. For example, the thermal transfer image 4 can be formed on one side of the substrate sheet 1 using the thermal head, and the substrate sheet 1 can be turned over and the thermal transfer image 5 can be formed on the other side of the substrate sheet 1 using the same thermal head.

[0024] Next, a separately prepared protective layer transfer sheet is used to thermally transfer protective layers 6 and 7 onto the receiving layers 2 and 3 on which the thermally transferred images 4 and 5 have been formed, thereby obtaining a printed product. The protective layers 6 and 7 cover at least a portion of the thermally transferred images 4 and 5.

[0025] An example of a protective layer transfer sheet is shown in Figure 5. The protective layer transfer sheet is formed by laminating a release layer 22 and an adhesive layer 23 in this order on one surface of a substrate 21. The release layer 22 becomes the release layers 17 and 18 of the printed matter shown in Figure 2. The adhesive layer 23 becomes the adhesive layers 15 and 16 of the printed matter shown in Figure 2.

[0026] A thermal transfer sheet having a dye layer and a protective layer provided in face order may be used to form a thermal transfer image and thermally transfer the protective layer onto a thermal transfer image-receiving sheet.

[0027] Each layer constituting the print will be described in detail below. (Base sheet) The substrate sheet 1 has a role of holding the receiving layer, and since heat is applied during thermal transfer, it is preferable that the substrate sheet 1 has a mechanical strength sufficient to allow handling without any problems even when heated. The material of such a substrate sheet is not particularly limited, and examples thereof include condenser paper, glassine paper, parchment paper, paper with a high degree of sizing, i.e., paper with high aqueous solution permeability, synthetic paper (polyolefin-based, polystyrene-based, etc.), fine paper, art paper, coated paper, cast-coated paper, wallpaper, backing paper, synthetic resin or emulsion-impregnated paper, synthetic rubber latex-impregnated paper, synthetic resin-filled paper, paperboard, cellulose fiber paper, or polyester, polyacrylate, polycarbonate, polyurethane, polyimide, polyetherimide, cellulose derivatives, polyethylene, ethylene-vinyl acetate copolymer, polypropylene, polystyrene, acrylic, polyvinyl chloride, etc. The material is not particularly limited, and various plastic films or sheets such as vinyl, polyvinylidene chloride, polyvinyl alcohol, polyvinyl butyral, nylon, polyether ether ketone, polysulfone, polyether sulfone, tetrafluoroethylene, perfluoroalkyl vinyl ether, polyvinyl fluoride, tetrafluoroethylene-ethylene, tetrafluoroethylene-hexafluoropropylene, polychlorotrifluoroethylene, and polyvinylidene fluoride can be used. Furthermore, films (porous films) formed by adding a white pigment or filler to these synthetic resins to form a film and having microvoids inside the substrate can also be used.

[0028] Laminates made from any combination of the above-mentioned base sheets may also be used. Typical examples of such laminates include synthetic paper laminated with cellulose fiber paper and synthetic paper, or cellulose fiber paper laminated with a plastic film or sheet. Such laminated synthetic paper may be two-layered. From the perspective of the texture and feel of the substrate, three-layered or three-or-more-layered laminates are preferred, in which synthetic paper, plastic film, or porous film is laminated on both sides of cellulose fiber paper (used as a core material). The lamination method may be any method, such as dry lamination, wet lamination, or extrusion. The base sheet shown in FIG. 2 is a laminate in which porous films 11 and 12 are laminated on both sides of a core material 10 with adhesive layers 13 and 14. The thickness of these base sheets may be any thickness, typically between 10 μm and 300 μm. If the above-mentioned base sheet has poor adhesion to the layer to be formed on its surface, it is preferable to subject the surface to various primer treatments or corona discharge treatments.

[0029] (receptor layer) The receiving layers 2 and 3 of the thermal transfer image receiving sheet are intended to receive the sublimation dyes transferred from the thermal transfer sheet and maintain the formed image. Examples of resins that can form the receiving layers include polycarbonate resins, polyester resins, polyamide resins, acrylic resins, cellulose resins, polysulfone resins, polyvinyl chloride resins, polyvinyl acetate resins, vinyl chloride-vinyl acetate copolymer resins, polyvinyl acetal resins, polyvinyl butyral resins, polyurethane resins, polystyrene resins, polypropylene resins, polyethylene resins, ethylene-vinyl acetate copolymer resins, and epoxy resins.

[0030] The thermal transfer image receiving sheet may contain a release agent in the receiving layer to improve releasability from the thermal transfer sheet. Examples of release agents include solid waxes such as polyethylene wax, amide wax, and Teflon (registered trademark) powder; fluorine-based or phosphate ester-based surfactants; various modified silicone oils such as silicone oil, reactive silicone oil, and curable silicone oil; and various silicone resins, with silicone oil being preferred. While oily silicone oils can also be used, curable silicone oils are preferred. Examples of curable silicone oils include reactive curable, photocurable, and catalytic curable types, with reactive curable and catalytic curable silicone oils being particularly preferred.

[0031] The amount of these curable silicone oils added is preferably 0.5% by mass to 30% by mass of the resin constituting the receiving layer. Alternatively, a release agent layer may be formed by dissolving or dispersing the release agent in a suitable solvent, applying it to a portion of the surface of the receiving layer, and then drying it. The thickness of the release agent layer is preferably 0.01 μm to 5.0 μm, particularly 0.05 μm to 2.0 μm. If silicone oil is added during the formation of the receiving layer, the release agent layer can be formed even if the silicone oil bleeds out onto the surface after application and is cured. When forming the receiving layer, pigments and fillers such as titanium oxide, zinc oxide, kaolin, clay, calcium carbonate, and finely powdered silica may be added to improve the whiteness of the receiving layer and further enhance the clarity of the transferred image. Plasticizers such as phthalate ester compounds, sebacate ester compounds, and phosphate ester compounds may also be added.

[0032] The thermal transfer image receiving sheet is obtained by applying and drying a receiving layer to at least one surface of the substrate sheet containing the thermoplastic resin and other necessary additives, such as a release agent, plasticizer, filler, crosslinking agent, curing agent, catalyst, thermal release agent, UV absorber, antioxidant, and light stabilizer, dissolved in an appropriate organic solvent or dispersed in an organic solvent or water, using a method such as gravure printing, screen printing, or reverse roll coating using a gravure plate. The application of the intermediate layer, etc., described below, is also carried out using the same method as for forming the receiving layer. The thickness of the receiving layer is approximately 0.5 μm to 50 μm, preferably approximately 2 μm to 10 μm. A receiving layer thickness of 0.5 μm or more improves releasability from the thermal transfer sheet. Furthermore, a receiving layer thickness of 50 μm or less facilitates drying during the coating process.

[0033] (middle class) Any conventionally known intermediate layer 8, 9 may be provided between the receiving layer 2, 3 and the substrate sheet 1 for the purpose of imparting adhesion, whiteness, cushioning, hiding power, antistatic properties, anti-curl properties, etc. between the receiving layer 2, 3 and the substrate sheet 1. Examples of binder resins used in the intermediate layer include polyurethane resins, polyester resins, polycarbonate resins, polyamide resins, acrylic resins, polystyrene resins, polysulfone resins, polyvinyl chloride resins, polyvinyl acetate resins, vinyl chloride-vinyl acetate copolymer resins, polyvinyl acetal resins, polyvinyl butyral resins, polyvinyl alcohol resins, epoxy resins, cellulose resins, ethylene-vinyl acetate copolymer resins, polyethylene resins, and polypropylene resins. For those of these resins having active hydroxyl groups, their isocyanate-cured products can also be used as binders.

[0034] Fillers such as titanium oxide, zinc oxide, magnesium carbonate, and calcium carbonate may be added to impart whiteness and hiding power. Furthermore, stilbene compounds, benzimidazole compounds, and benzoxazole compounds may be added as fluorescent brighteners to enhance whiteness. Hindered amine compounds, hindered phenol compounds, benzotriazole compounds, and benzophenone compounds may be added as ultraviolet absorbers or antioxidants to improve the light resistance of printed matter. Cationic acrylic resins, polyaniline resins, and various conductive fillers may also be added to impart antistatic properties. The thickness of the intermediate layer is, for example, approximately 0.5 μm to 30 μm.

[0035] (protective layer) The protective layers 6 and 7 provided on the front and back surfaces of the print of the present disclosure are formed by thermally transferring a protective layer transfer sheet, which has a heat-transferable protective layer on a substrate, onto an image-formed image-receiving sheet. This protective layer is composed of at least one thermally transferable resin layer and can be formed from various resins conventionally known as protective layer-forming resins. Examples of protective layer-forming resins include thermoplastic resins such as polyester resins, polystyrene resins, acrylic resins, styrene-acrylic resins, polyurethane resins, acrylic urethane resins, epoxy resins, phenoxy resins, silicone-modified resins of these resins, mixtures of these resins, ionizing radiation-curable resins, and ultraviolet-blocking resins. UV absorbers, organic fillers, inorganic fillers, and the like may also be added as needed.

[0036] A protective layer made of an ionizing radiation curable resin has excellent plasticizer resistance and abrasion resistance. Known ionizing radiation curable resins can be used, including, for example, a radical polymerizable polymer or oligomer that is crosslinked and cured by irradiating with ionizing radiation, optionally containing a photopolymerization initiator, and polymerized and crosslinked by electron beams or ultraviolet rays. The ionizing radiation curable resin can also be added to the release layer or adhesive layer of the thermal transfer image protection sheet.

[0037] The main purpose of a protective layer containing an ultraviolet-blocking resin or an ultraviolet absorber is to impart lightfastness to the printed matter. Examples of ultraviolet-blocking resins that can be used include resins obtained by reacting or bonding a reactive ultraviolet absorber with a thermoplastic resin or the above-mentioned ionizing radiation-curable resin. More specifically, examples include those in which a reactive group such as an addition-polymerizable double bond (e.g., a vinyl group, an acryloyl group, a methacryloyl group, etc.), an alcoholic hydroxyl group, an amino group, a carboxyl group, an epoxy group, or an isocyanate group has been introduced into a conventional non-reactive organic ultraviolet absorber such as a salicylate, a phenyl acrylate, a benzophenone, a benzotriazole, a coumarin, a triazine, or a nickel chelate.

[0038] The ultraviolet absorber is a conventionally known non-reactive organic ultraviolet absorber, such as a salicylate, phenyl acrylate, benzophenone, benzotriazole, coumarin, triazine, or nickel chelate. The ultraviolet blocking resin or ultraviolet absorber can also be added to the release layer or adhesive layer of the thermal transfer image protection sheet. The amount of the ultraviolet blocking resin or ultraviolet absorber added is 1% (by mass) to 30% (by mass), preferably 5% (by mass) to 20% (by mass), of the binder resin.

[0039] Specific examples of organic and / or inorganic fillers include polyethylene wax, bisamide, nylon, acrylic resin, cross-linked polystyrene, silicone resin, silicone rubber, talc, calcium carbonate, titanium oxide, microsilica, colloidal silica, and other silica particles, but any of these can be used without any particular limitations. However, they should have good slip properties and a particle size of 10 μm or less, more preferably 0.1 μm or more and 3 μm or less. The amount of filler added is preferably in the range of more than 0 parts by mass and 100 parts by mass or less per 100 parts by mass of the resin content, so that transparency is maintained when the protective layer is transferred.

[0040] The protective layer can be formed by preparing an ink for forming the protective layer by adding the above-described resin for forming the protective layer and, if necessary, additives such as an ultraviolet absorber, an organic filler and / or an inorganic filler, and dissolving or dispersing the ink in an appropriate solvent, and then applying the ink to the support by a method such as gravure printing, screen printing, or reverse coating using a gravure plate, and then drying the ink.

[0041] The thickness of the layer to be transferred (thermal transferable resin layer) of the protective layer transfer sheet is about 0.3 μm to 10 μm, preferably 0.5 μm to 5 μm. If the protective layer has the functions of a release layer or an adhesive layer, the thermal transferable resin layer can be constituted by a single protective layer, and the layer configuration of the thermal transferable resin can be changed as appropriate.

[0042] (peeling layer) The release layers 17 and 18 in the protective layer 6 are composed of a binder resin. Examples of the binder resin include thermoplastic resins and thermosetting resins known in the art. Examples of the thermoplastic resin include acrylic resins such as polymethacrylic acid, polymethacrylamide, polymethyl methacrylate, polyethyl methacrylate, and polybutyl acrylate; vinyl resins such as polyvinyl acetate, vinyl chloride-vinyl acetate copolymer, polyvinyl alcohol, and polyvinyl butyral; cellulose derivatives such as ethyl cellulose, nitrocellulose, and cellulose acetate; and styrene-acrylic resins. The release layer is a layer that is peeled off from the substrate of the protective layer transfer sheet by thermal transfer and forms the outermost surface of the printed matter. Among the above-mentioned thermoplastic resins, acrylic resins and styrene-acrylic resins are preferably used from the viewpoints of adequate adhesion to the substrate of the protective layer transfer sheet, thermal peelability, gloss, and scratch resistance.

[0043] Examples of thermosetting resins include unsaturated polyester resins, polyester resins, polyurethane resins, aminoalkyd resins, etc. These binder resins may be used alone or in combination of two or more.

[0044] The release layer may contain a wax together with the binder resin. When wax is contained, the abrasion resistance and peelability of the release layer are improved, and the amplitude of the dynamic friction coefficient when the release layers contact each other can be reduced. Examples of waxes include polyethylene wax, polyester wax, polystyrene powder, olefin powder, microcrystalline wax, carnauba wax, paraffin wax, Fischer-Tropsch wax, various low-molecular-weight polyethylenes, Japan wax, beeswax, whale wax, wool wax, shellac wax, candelilla wax, petrolactam, partially modified wax, fatty acid ester, fatty acid amide, etc.

[0045] The wax content in the release layer is typically about 0.1% by mass to about 30% by mass, preferably about 0.1% by mass to about 10% by mass. The release layer may also contain an ultraviolet absorber. The incorporation of an ultraviolet absorber can improve the light resistance and weather resistance of the image on the transfer substrate that is covered with the protective layer after transfer. Examples of ultraviolet absorbers that can be used include conventionally known organic ultraviolet absorbers such as salicylates, benzophenones, benzotriazoles, substituted acrylonitriles, nickel chelates, and hindered amines. Furthermore, the release layer may contain an ultraviolet-absorbing resin in which an addition-polymerizable double bond such as a vinyl group, acryloyl group, or methacryloyl group, or a functional group such as an alcoholic hydroxyl group, amino group, carboxyl group, epoxy group, or isocyanate group, has been introduced into the ultraviolet absorber.

[0046] The release layer may contain silicone oil. The inclusion of silicone oil can reduce the coefficient of friction. The silicone oil is preferably a modified silicone oil, and aralkyl-modified silicone or long-chain alkyl-modified silicone is particularly preferred. The content of silicone oil in the protective layer is preferably 0.5% by mass or more and 20% by mass or less, more preferably 0.5% by mass or more and 10% by mass or less.

[0047] Silica particles such as microsilica and colloidal silica may be added to the release layer. The inclusion of silica particles can prevent blocking between double-sided printed images. The average particle size of the silica particles is preferably 10 μm or less, more preferably 0.1 μm to 6 μm. The average particle size is measured by electron microscopy. Specifically, the particle size is calculated by averaging the major and minor axis diameters of each particle using electron microscopy, and the arithmetic mean of the particle diameters of 100 particles is used as the average particle size. The amount of silica particles added is preferably in the range of 1 part by mass to 10 parts by mass per 100 parts by mass of the resin content, so that transparency is maintained when the release layer is transferred.

[0048] Furthermore, various additives such as antioxidants and fluorescent brighteners may be contained in the release layer. The release layer is formed by applying an ink prepared by adding necessary additives such as wax to the binder resin and dissolving or dispersing the ink in a solvent such as water or an organic solvent to the substrate sheet by a conventional coating method such as gravure printing, screen printing, or reverse roll coating using a gravure plate, and then drying the ink. The thickness of the release layer is about 0.1 μm to 10 μm, preferably about 0.5 μm to 5 μm.

[0049] (Adhesive layer) The protective layer transfer sheet may have adhesive layers 15 and 16 on the surfaces of the protective layer and release layer to improve transferability and adhesion to the print object, which is the transfer recipient. Any conventionally known pressure-sensitive adhesive or heat-sensitive adhesive can be used for this adhesive layer, but it is preferable that it be formed from a thermoplastic resin with a glass transition temperature (Tg) of 40° C. or higher and 80° C. or lower, and for example, one with an appropriate glass transition temperature can be selected from polyester resin, vinyl chloride-vinyl acetate copolymer resin, acrylic resin, ultraviolet-blocking resin, butyral resin, epoxy resin, polyamide resin, vinyl chloride resin, etc.

[0050] The UV-blocking resin is the same as that described for the protective layer. A coating liquid containing additives such as UV absorbers and inorganic or organic fillers, as needed, is applied and dried to form a layer with a thickness of approximately 0.5 μm to 10 μm. By making the adhesive layer 0.5 μm or thicker, the adhesion between the printed matter and the thermally transferable resin layer is improved, suppressing transfer defects during printing. By making the adhesive layer 10 μm or thicker, the decrease in transfer sensitivity during thermal transfer of the protective layer is suppressed, facilitating uniform thermal transfer of the protective layer.

[0051] (Release layer) The protective layer transfer sheet has a protective layer of a thermally transferable resin layer consisting of at least one layer that can be peeled off from the substrate, but a release layer may be provided between the substrate and the thermally transferable resin layer. The provision of the release layer makes it easier to peel the thermally transferable resin layer from the substrate. The release layer does not peel off from the substrate when heated, and is not transferred to the print that is the transfer target. Therefore, the surface of this release layer that comes into contact with the thermally transferable resin layer becomes the peeling surface (release surface) and the protective layer surface of the print.

[0052] Examples of resins that can be used to form the release layer include various waxes such as silicone wax, silicone resins, fluororesins, acrylic resins, polyurethane resins, polyvinylpyrrolidone resins, polyvinyl alcohol resins, and polyvinyl acetal resins. Microparticles may be added to improve film strength. Among the above resins, acrylic resins, such as acrylic acid and methacrylic acid alone, or copolymers thereof with other monomers, are preferred, as they offer excellent adhesion to the substrate and releasability from the protective layer. The thickness of the release layer is approximately 0.05 μm to 5 μm, and preferably approximately 0.5 μm to 3 μm.

[0053] In the printed matter of the present disclosure, the coefficient of dynamic friction between the front and back surfaces (opposing surfaces) of the printed matter when stacked is preferably 0.9 or less, and particularly preferably 0.4 or less. Furthermore, the amplitude of the coefficient of dynamic friction between the front and back surfaces of the printed matter when stacked is preferably 0.45 or less. The coefficients of dynamic friction calculated by a dynamic friction coefficient calculation method from the maximum and minimum values ​​of the amplitude of the dynamic friction force when measuring the coefficient of dynamic friction are called the maximum coefficient of dynamic friction and the minimum coefficient of dynamic friction, respectively, and the absolute value of the difference between the maximum coefficient of dynamic friction and the minimum coefficient of dynamic friction is called the amplitude of the coefficient of dynamic friction.

[0054] An example of a friction force measurement chart is shown in Figure 6. The first peak on the measurement chart corresponds to the static friction force, which is the force required to start a stationary object moving. The points on the measurement chart after the static friction force correspond to the kinetic friction force.

[0055] Figure 7 shows an example of the kinetic friction force portion of the friction force measurement chart. The maximum kinetic friction coefficient is determined from the maximum value of the kinetic friction force, and the minimum kinetic friction coefficient is determined from the minimum value of the kinetic friction force.

[0056] The dynamic friction coefficients specified in this disclosure are all values ​​measured in accordance with the method of JIS K 7125:1999. Under conditions where the front and back surfaces of a printed object are in contact with each other, a vertical load (point pressure of 200 g) is applied using a ball indenter, and the ball indenter is slid across the sample surface at a speed of 500 mm / min to measure the dynamic friction coefficient. By ensuring that the dynamic friction coefficient between the front and back surfaces of two printed objects is 0.9 or less and that the amplitude of the dynamic friction coefficient is 0.45 or less, it is possible to prevent the front and back surfaces of the printed objects from rubbing against each other and generating abnormal noise when handling multiple printed objects stacked together.

[0057] In the above embodiment, the printed matter has thermal transfer images formed on both sides, but as shown in Figures 3 and 4, it is also possible to provide a receiving layer 2 and a protective layer 6 on one side (front side) of the base sheet 1, a back side layer 19 on the other side (back side), and form a thermal transfer image 4 only on the front side.

[0058] As the binder resin constituting the back surface layer 19, various known thermoplastic resins can be used. However, from the viewpoints of stain resistance of the back surface by dyes, writability, film-forming properties, etc., it is preferable to use polyvinyl butyral resin, polyvinyl acetal resin, acrylic ester resin, polyvinylpyrrolidone, or a mixed resin thereof.

[0059] 3 and 4, when folded so that the surface on which the thermally transferred image is formed faces inward, the coefficient of dynamic friction between the opposing surfaces is 0.9 or less, and the amplitude of the coefficient of dynamic friction is 0.45 or less. This prevents the image-forming surfaces of the printed materials from rubbing against each other and generating noise when the printed materials are handled in a folded state. [Example]

[0060] The present disclosure will now be described in more detail with reference to examples, but the present disclosure is not limited to these examples.

[0061] Example 1 <Preparation of protective layer transfer sheet> An ink for a heat-resistant slipping layer having the following composition was applied to one side of a 6 μm thick polyethylene terephthalate film by the gravicoat method, dried, and then subjected to a curing treatment to form a heat-resistant slipping layer having a thickness of 1.0 μm. (Ink composition for heat-resistant slip layer) Polyvinyl butyral resin 4.55 parts by mass (S-LEC BX-1, Sekisui Chemical Co., Ltd.) Polyisocyanate 21.0 parts by mass (Burnoc D750-45, solids content 45% by mass, Dainippon Ink and Chemicals, Inc.) Phosphate ester surfactant 3.0 parts by mass (Plysurf A208N, Daiichi Pharmaceutical Co., Ltd.) Talc (Microace P-3, Nippon Talc Kogyo Co., Ltd.) 0.7 parts by mass Methyl ethyl ketone 100 parts by mass Toluene 100 parts by mass

[0062] Next, a release layer ink having the following composition was applied by gravure coating to the surface opposite to the surface on which the heat-resistant slip layer was formed, and dried to form a release layer having a thickness of 0.7 μm. (Composition of ink for release layer) Polymethyl methacrylate (PMMA) 12 parts by weight (Dianal BR-87, weight average molecular weight 25,000, Mitsubishi Chemical Corporation) Styrene acrylic resin 5 parts by mass (Dianal BR-52, weight average molecular weight 85,000, Mitsubishi Chemical Corporation) Long-chain alkyl-modified silicone oil 1 part by mass (KF412, Shin-Etsu Chemical Co., Ltd.) Methyl ethyl ketone 40 parts by mass Toluene 40 parts by mass

[0063] An adhesive layer ink having the following composition was applied onto the release layer and dried to form an adhesive layer having a thickness of 1.0 μm, thereby obtaining a protective layer transfer sheet. (Composition of ink for adhesive layer) Polyester resin (Vylon 700, Toyobo Co., Ltd.) 27 parts by weight 7 parts by weight of UVA-containing acrylic resin (PUVA-50M-40TM, Otsuka Chemical Co., Ltd.) ·UVA compound 3.5 parts by mass (Tinuvin 900, Ciba Specialty Chemicals Co., Ltd.) Silica particles 0.5 parts by mass (Silysia 310P, average particle size 2.7 μm, Fuji Silysia Chemical Ltd.) Methyl ethyl ketone 31 parts by mass Toluene 31 parts by mass

[0064] <Production of thermal transfer image receiving sheet> (See the structure in Figure 2) The core material 10 is Pearl Coat N (157.0 g / m 2Adhesive was applied to both sides of a sheet of Pearl Coat N (Mitsubishi Paper Mills, Ltd.) using a gravure coater and dried to form 5-0 μm thick adhesive layers 13 and 14. 35 μm thick porous films 11 and 12 (Toyopearl SS, Toyobo Co., Ltd.) were then dry laminated to both sides of the Pearl Coat N to produce a substrate sheet 1 consisting of three laminated substrates.

[0065] An intermediate layer coating solution having the following composition was applied to one side of the prepared substrate sheet using a gravure coater and dried at 110°C for 1 minute to form an intermediate layer having a thickness of 2 μm. A receiving layer coating solution having the following composition was applied to the intermediate layer using a gravure coater and dried at 110°C for 1 minute to form a receiving layer having a thickness of 4 μm. An intermediate layer and a receiving layer were laminated on the other side of the substrate sheet in the same manner as above to prepare a thermal transfer image receiving sheet having receiving layers on both sides of the substrate sheet.

[0066] (Composition of coating liquid for intermediate layer) Polyester resin (WR-905, Nippon Synthetic Chemical Industry Co., Ltd.) 13.1 parts by mass Titanium oxide (TCA-888, Tochem Products) 26.2 parts by mass Fluorescent whitening agent 0.39 parts by weight (Benzimidazole derivative, product name: TINOPAL IJT, Ciba Specialty Chemicals) Water / isopropyl alcohol (IPA) (2 / 1 by weight) 60 parts by weight

[0067] (Receptor layer coating liquid composition) Vinyl chloride-vinyl acetate copolymer (Solvine C, Nissin Chemical Industry Co., Ltd.) 60 parts by mass Epoxy-modified silicone (X-22-3000T, Shin-Etsu Chemical Co., Ltd.) 1.2 parts by mass Methylstyrene-modified silicone (X-24-510, Shin-Etsu Chemical Co., Ltd.) 0.6 parts by mass Methyl ethyl ketone / toluene (1 / 1 mass ratio) 5 parts by mass

[0068] Using the thermal transfer image receiving sheet prepared above, a dye sublimation thermal transfer printer (DS820DX, Dai Nippon Printing Co., Ltd.), and the original thermal transfer sheet of the dye sublimation thermal transfer printer, a black solid image was formed, and the protective layer transfer sheet prepared above was heated. A protective layer consisting of a peel layer and an adhesive layer was thermally transferred in gloss mode to both sides of the thermal transfer image receiving sheet on which the solid image had been formed, thereby producing the printed matter of Example 1.

[0069] Example 2 A printed matter of Example 2 was obtained in the same manner as in Example 1, except that the ink for the release layer was changed to the following composition.

[0070] (Composition of ink for release layer) Polymethyl methacrylate (PMMA) 12 parts by weight (Dianal BR-87, weight average molecular weight 25,000, Mitsubishi Chemical Corporation) Styrene acrylic resin 5 parts by mass (Dianal BR-52, weight average molecular weight 85,000, Mitsubishi Chemical Corporation) Long-chain alkyl-modified silicone oil 1 part by mass (KF412, Shin-Etsu Chemical Co., Ltd.) Silica particles 1 part by mass (Silysia 310P, average particle size 2.7 μm, Fuji Silysia Chemical Ltd.) Methyl ethyl ketone 40 parts by mass Toluene 40 parts by mass

[0071] Example 3 The print of Example 3 was obtained in the same manner as in Example 2, except that a protective layer consisting of a release layer and an adhesive layer was thermally transferred in matte mode to both sides of the thermal transfer image-receiving sheet on which a solid image had been formed.

[0072] Example 4 A printed matter of Example 4 was obtained in the same manner as in Example 1, except that the ink for the release layer was changed to the following composition.

[0073] (Composition of ink for release layer) Polymethyl methacrylate (PMMA) 12 parts by weight (Dianal BR-87, weight average molecular weight 25,000, Mitsubishi Chemical Corporation) Styrene acrylic resin 5 parts by mass (Dianal BR-52, weight average molecular weight 85,000, Mitsubishi Chemical Corporation) Aralkyl-modified silicone oil 1 part by mass (KF410, Shin-Etsu Chemical Co., Ltd.) Silica particles 1 part by mass (Silysia 310P, average particle size 2.7 μm, Fuji Silysia Chemical Ltd.) Methyl ethyl ketone 40 parts by mass Toluene 40 parts by mass

[0074] Example 5 A printed matter of Example 5 was obtained in the same manner as in Example 1, except that the ink for the release layer was changed to the following composition.

[0075] (Composition of ink for release layer) Polymethyl methacrylate (PMMA) 12 parts by weight (Dianal BR-87, weight average molecular weight 25,000, Mitsubishi Chemical Corporation) Styrene acrylic resin 5 parts by mass (Dianal BR-52, weight average molecular weight 85,000, Mitsubishi Chemical Corporation) Aralkyl-modified silicone oil 1 part by mass (KF410, Shin-Etsu Chemical Co., Ltd.) Silica particles 1 part by mass (Silysia 310P, average particle size 2.7 μm, Fuji Silysia Chemical Ltd.) Polyethylene wax 1 part by mass Methyl ethyl ketone 40 parts by mass Toluene 40 parts by mass

[0076] Example 6 A printed matter of Example 6 was obtained in the same manner as in Example 1, except that the ink for the release layer was changed to the following composition.

[0077] (Composition of ink for release layer) Polymethyl methacrylate (PMMA) 12 parts by weight (Dianal BR-87, weight average molecular weight 25,000, Mitsubishi Chemical Corporation) Styrene acrylic resin 5 parts by mass (Dianal BR-52, weight average molecular weight 85,000, Mitsubishi Chemical Corporation) Polyethylene wax 1 part by mass Methyl ethyl ketone 40 parts by mass Toluene 40 parts by mass

[0078] Example 7 An adhesive layer, a porous film, an intermediate layer and a receiving layer were laminated on only one side of the core material, and a thermal transfer image receiving sheet was prepared in which a receiving layer was provided on only one side of the base sheet.The print of Example 7 was obtained in the same manner as Example 2, except that a solid image was formed on one side of the thermal transfer image receiving sheet.

[0079] (Comparative Example 1) A printed matter of Comparative Example 1 was obtained in the same manner as in Example 1, except that the ink for the release layer was changed to the following composition.

[0080] (Composition of ink for release layer) Polymethyl methacrylate (PMMA) 12 parts by weight (Dianal BR-87, weight average molecular weight 25,000, Mitsubishi Chemical Corporation) Styrene acrylic resin 5 parts by mass (Dianal BR-52, weight average molecular weight 85,000, Mitsubishi Chemical Corporation) Methyl ethyl ketone 40 parts by mass Toluene 40 parts by mass

[0081] (Comparative Example 2) The print of Comparative Example 2 was obtained in the same manner as Comparative Example 1, except that a protective layer consisting of a release layer and an adhesive layer was thermally transferred in matte mode to both sides of the thermal transfer image-receiving sheet on which a solid image had been formed.

[0082] (Comparative Example 3) A printed matter of Comparative Example 3 was obtained in the same manner as in Example 1, except that the ink for the release layer was changed to the following composition.

[0083] (Composition of ink for release layer) Polymethyl methacrylate (PMMA) 17 parts by weight (Dianal BR-87, weight average molecular weight 25,000, Mitsubishi Chemical Corporation) Epoxy-modified silicone oil 1 part by mass (KP-1800U, Shin-Etsu Chemical Co., Ltd.) Methyl ethyl ketone 40 parts by mass Toluene 40 parts by mass

[0084] The prints produced by the methods shown in the above examples and comparative examples were subjected to measurement of 20-degree gloss, measurement of dynamic friction coefficient, evaluation of noise caused by rubbing of prints against each other, and evaluation of sticking when prints were stacked. The measurement and evaluation methods are explained below.

[0085] <20 degree gloss measurement> The 20-degree gloss was measured at three locations using the spectrophotometer described below in accordance with Method 5 of JIS Z 8741 (published in 1997), and the average value was calculated. The measurement results (average values) are shown in Table 1. (spectrophotometer) Konica Minolta, Inc., Rhopoint IQ-S ·Reflection angle: 20 degrees

[0086] <Measurement of dynamic friction coefficient> Using a surface property measuring device (Shinto Scientific Co., Ltd., Haydon Tripogear Type: 14DR), the dynamic friction coefficients of the printed materials produced in each Example and Comparative Example were measured using two printed materials with the same conditions for each Example. The front surface of one printed material was in contact with the back surface of the other printed material, and a vertical load (200 g point pressure) was applied with a ball indenter. The ball indenter was slid across the sample surface at a speed of 500 mm / min. The printed materials used were conditioned for at least 16 hours in an environment of 23±2°C and (50±6)% RH. The printed material of Example 7 was folded so that the image-bearing surfaces were facing inward, and the measurement was performed under these conditions. This measurement was performed five times, and the average value was used as the dynamic friction coefficient. All dynamic friction coefficients were measured in accordance with the method of JIS K7125:1999. The measurement environment was a temperature of 25°C and a humidity of 50% RH. The results are shown in Table 1. The printed matter of Comparative Examples 1 to 3 had discontinuous and unstable waveforms, and the dynamic friction coefficient could not be measured.

[0087] The coefficients of kinetic friction calculated from the maximum and minimum values ​​of the amplitude of the kinetic friction force during measurement are called the maximum and minimum coefficients of kinetic friction, respectively, and the amplitude of the coefficient of kinetic friction was calculated from the absolute value of the difference between the maximum and minimum coefficients of kinetic friction. The results are shown in Table 1.

[0088] <Conditions and methods for evaluating abnormal noise occurrence> Ten printed materials produced in Examples 1 to 6 and Comparative Examples 1 to 3 were stacked under the same conditions, with one edge of the printed material adhered to the spine so that covers were attached to the front and back, and the covers were attached in a U-shape. Using this booklet-shaped photo album, adjacent printed materials were rubbed together, the generated sound was listened to, and the results were evaluated according to the following criteria. The evaluation results are shown in Table 1. Furthermore, the printed material of Example 7 was folded so that the protective layer-forming surface was on the inside, and the back surfaces were glued together to create a booklet-shaped photo album with 10 stacked printed materials. Opposing surfaces were rubbed together, the generated sound was listened to, and the results were evaluated according to the following criteria. The evaluation results are shown in Table 1. The environment in which the generated sound was listened to was a temperature of 25°C and a humidity of 50% RH.

[0089] <<Evaluation criteria for abnormal noise occurrence>> A: No harsh sounds were generated. B: There was a squeaking noise, but it wasn't bothersome. C: It produced an annoying squeaking noise and was damaging to people.

[0090] <Adhesion evaluation> The booklet-shaped photo albums prepared for the evaluation of the occurrence of abnormal noises were opened, and the opposing surfaces were visually inspected to see if they were sticking together. The sticking was evaluated based on the following evaluation criteria. The evaluation results are shown in Table 1.

[0091] <<Evaluation criteria for sticking>> A: No sticking occurred. C: Sticking occurred.

[0092] [Table 1]

[0093] Although the present disclosure has been described in detail with reference to specific embodiments, it will be apparent to those skilled in the art that various modifications can be made without departing from the spirit and scope of the present disclosure. [Explanation of symbols]

[0094] 1 Base sheet 2,3 Receptor 4,5 Thermal transfer images 6,7 protective layer

Claims

1. A base sheet; a receiving layer provided on each side of the substrate sheet and having a thermal transfer image formed thereon; protective layers provided so as to cover the receiving layers on both sides of the base sheet; A print comprising: A printed matter in which the absolute value of the difference between the maximum and minimum values ​​of the dynamic friction coefficient measured is 0.45 or less when a ball indenter is used to apply a vertical load (point pressure of 200 g) and slide the ball indenter over the sample surface at a speed of 500 mm / min under the condition that the surface with the protective layer of one of the two printed matters is in contact with the surface with the protective layer of the other printed matter, based on the method of JIS K 7125:1999.

2. 2. The print according to claim 1, wherein the dynamic friction coefficient is 0.9 or less.

3. 2. The printed matter according to claim 1, wherein the outermost layer contains an aralkyl-modified silicone oil or a long-chain alkyl-modified silicone oil.

4. The printed matter according to claim 1 , wherein the outermost layer contains silica particles.

5. 2. The print according to claim 1, wherein the outermost layer contains a styrene-acrylic resin.

6. A base sheet; a receiving layer provided on one surface of the base sheet and having a thermal transfer image formed thereon; a protective layer provided to cover the receiving layer; A print comprising: A printed matter in which the absolute value of the difference between the maximum and minimum values ​​of the dynamic friction coefficient measured is 0.45 or less when the printed matter is folded in accordance with the method of JIS K 7125:1999 so that the surface on which the thermal transfer image is formed is on the inside and the opposing surfaces are in contact with each other, and a vertical load (point pressure of 200 g) is applied using a ball indenter and the ball indenter is slid across the sample surface at a speed of 500 mm / min.

7. A protective layer transfer sheet comprising a release layer and an adhesive layer laminated in this order on one surface of a substrate, The protective layer transfer sheet, wherein the release layer contains a styrene-acrylic resin and at least one of silicone oil and polyethylene wax.

8. The protective layer transfer sheet according to claim 7 , wherein the silicone oil is an aralkyl-modified silicone oil or a long-chain alkyl-modified silicone oil.

Images