JP5251793B2 - Protective layer thermal transfer sheet and printed matter - Google Patents

Description

  The present invention relates to a protective layer thermal transfer sheet and a printed matter. More specifically, the present invention relates to a protective layer thermal transfer sheet capable of improving the storage stability of a printed material having an aqueous receiving layer having an image on a substrate, and a printed material using the same.

  Conventionally, an image such as a gradation image, a monotonous image such as a character, a symbol, or the like is formed using a thermal transfer method. As the thermal transfer system, a thermal sublimation transfer system and a thermal melt transfer system are widely used.

  Among these, the thermal sublimation transfer method uses a thermal transfer sheet in which a dye layer in which a sublimation dye used as a coloring material is dissolved or dispersed in a binder resin is supported on a base sheet, and this thermal transfer sheet is superposed on an image receiving sheet to perform thermal transfer. In this method, an energy corresponding to image information is applied by a heating device such as a head to transfer the sublimation dye contained in the dye layer on the thermal transfer sheet to the image receiving sheet to form an image.

  This heat-sensitive sublimation transfer method can control the amount of dye transfer in dot units according to the amount of energy applied to the thermal transfer sheet, and is therefore excellent in forming gradation images, and has the advantage of easy formation of characters, symbols, etc. Have.

  The image formed by the above heat-sensitive sublimation transfer method protects the image because the transferred dye is present on the surface of the transfer target, and also on the image from the viewpoint of image protection such as light resistance and scratch resistance. Many techniques for forming a protective layer are known (for example, Patent Documents 1 to 3).

  Here, as the other side of the thermal transfer sheet provided with the protective layer, that is, the image-formed transfer object onto which the protective layer is transferred, a solvent-based image receiving sheet including a solvent-based dye-receiving layer and a water-based dye-receiving layer. An aqueous image-receiving sheet comprising According to the solvent-based image-receiving sheet, the image formed on the solvent-based image-receiving sheet is a water-based image-receiving sheet, although it is superior in releasability between the dye layer and the dye-receiving layer as compared with the water-based image-receiving sheet. Since the glossiness of an image formed on a sheet is low, a solvent-based image receiving sheet is not suitable for use when a high glossiness is required. Furthermore, solvent-based image-receiving sheets have a strong irritating odor, which causes health damage when sucked into the human body, and tends to be avoided from use due to problems such as environmental impact due to treatment of waste liquids and the like.

  On the other hand, according to the water-based image receiving sheet, there is no influence on the human body and the environment, and high glossiness can be imparted to the image formed as compared with the solvent-based image receiving sheet.

Japanese Patent Laid-Open No. 7-276831 JP 2000-71626 A JP 2006-228772 A

  However, when a thermal transfer sheet having such a protective layer is applied to an image formed on the above-described aqueous image-receiving sheet, the printed matter on which the image is formed is then formed of a film made of vinyl chloride or the like. If the plasticizer contained in the film penetrates the receptor layer, the dye of the image formed on the aqueous image-receiving sheet dissolves in the plasticizer. As a result, the image adheres to the film, so that the problem that the storability of the printed matter is deteriorated has occurred remarkably. Further, there has been a problem that an image formed on the water-based image receiving sheet is dried and cracked when stored for a long period of time.

  The present invention has been made in view of such a problem, and prevents an image of a printed matter after thermal transfer from adhering to a film or the like, and prevents an image formed on a water-based image receiving sheet from cracking. It is a main object of the present invention to provide a protective layer thermal transfer sheet for forming a protective layer capable of improving the storage stability of an object, and a print using the same.

  The present invention for solving the above problems is a protective layer thermal transfer sheet in which a release layer, an inorganic particle layer, and an adhesive layer are laminated in this order on a substrate sheet, and both the release layer and the adhesive layer are Methyl methacrylate and a reactive ultraviolet absorber are formed of a resin copolymerized at a reactive ultraviolet absorber ratio of 10 to 50% by weight, and contain additives at a rate of 10 to 50% by weight with respect to the resin. It is characterized by that.

  The present invention for solving the above problems is formed on a base sheet so as to cover at least a part of a porous layer containing a water-based binder and hollow particles as main components, a water-based receptive layer, and the water-based receptive layer. A printed matter comprising a protective layer, wherein the protective layer is formed by transfer using the protective layer thermal transfer sheet according to claim 1.

  According to the present invention, the inorganic particle layer is laminated on the protective layer thermal transfer sheet. For example, the protective layer is transferred to the image formed on the image receiving sheet using the aqueous receiving layer containing the aqueous binder resin. Even in the case where the printed matter on which the image is formed is sandwiched between the sheets formed with the film or stored in contact with the film, the plasticizer contained in the film remains in the aqueous receiving layer. Infiltration can be prevented more effectively. Therefore, it is possible to prevent the dye of the image formed in the aqueous receiving layer from dissolving in the plasticizer and adhere to the film, and improve the storage stability of the printed matter.

  In addition, according to the printed matter formed using the protective layer thermal transfer sheet having the above effects, the image dye formed on the water-based receiving layer can be prevented from dissolving in the plasticizer, so that the image is a film. Can be prevented from adhering to. Therefore, it is possible to form a printed matter with improved storage stability.

It is a section schematic diagram of a protection layer thermal transfer sheet concerning this embodiment. It is a cross-sectional schematic diagram of a protective layer thermal transfer sheet according to another embodiment. 1 is a schematic cross-sectional view of a printed material according to the present invention. It is a cross-sectional schematic diagram of the image receiving sheet which thermally transfers the protective layer thermal transfer sheet according to the present embodiment.

<Protective layer thermal transfer sheet>
(First embodiment)
Hereinafter, a first embodiment for carrying out the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic sectional view showing a protective layer thermal transfer sheet according to the first embodiment.

  As shown in FIG. 1, the protective layer thermal transfer sheet 10 of this embodiment is formed by laminating a base sheet 1, a release layer 2, an inorganic particle layer 3, and an adhesive layer 4. Hereinafter, each layer will be described.

(1) Base sheet 1
The base material sheet 1 can be a base material sheet used in a conventional protective layer thermal transfer sheet.

  For example, thin paper such as glassine paper, condenser paper, paraffin paper, polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polyphenylene sulfide, polyether ketone, polyether sulfone, etc., polyester, polypropylene, polycarbonate, cellulose acetate , Polyethylene derivatives, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyamide, polyimide, polymethylpentene, ionomer and other plastic stretched or unstretched films, surface of these materials subjected to easy adhesion treatment, The thing which laminated | stacked these materials is mentioned.

  The thickness of the substrate sheet 1 can be appropriately selected according to the material so that the strength, heat resistance and the like are appropriate, but it is usually preferably about 1 to 100 μm.

(2) Release layer 2
The release layer 2 in the present invention is formed of a resin obtained by copolymerizing methyl methacrylate and a reactive ultraviolet absorber.

  Here, conventionally known salicylate series, benzophenone series, benzotriazole series, substituted acrylonitrile series, nickel chelate series, hindered amine series and the like can be widely used as reactive ultraviolet absorbers that can be copolymerized with methyl methacrylate.

  Further, the resin obtained by copolymerizing methyl methacrylate and a reactive ultraviolet absorber is a resin copolymerized at a reactive ultraviolet absorber ratio of 10 to 50% by weight.

  In a resin obtained by copolymerizing methyl methacrylate and a reactive ultraviolet absorbent, if the reactive ultraviolet absorbent ratio is lower than 10%, the print is cracked when stored under high temperature and high humidity, which is not preferable.

  In addition, in a resin obtained by copolymerizing methyl methacrylate and a reactive ultraviolet absorber, if the reactive ultraviolet absorber ratio is higher than 50%, Tg (glass transition temperature) of the copolymerized resin is lowered, and there is a problem in storage stability. Occurs.

  In the present invention, the release layer contains additives such as an ultraviolet absorber, an antioxidant, and a fluorescent brightening agent in a proportion of 10 to 50% by weight with respect to these resins.

  If the blending ratio of the additive is less than 10% by weight with respect to the resin, cracks occur when the printed product is stored under high temperature and high humidity, which is not preferable.

  If the blending ratio of the additive is more than 50% by weight based on the resin, the scratch resistance of the printed material is lowered, which is not preferable.

  The release layer is an ordinary coating method such as a gravure printing method, a screen printing method, a reverse roll coating method using a gravure plate, or an ink obtained by dissolving or dispersing the above-mentioned resin and other additives in a solvent such as water or an organic solvent. According to the above, it is formed by coating and drying.

  The thickness of the release layer is usually about 0.1 to 10 μm, preferably about 0.5 to 5.0 μm.

(3) Inorganic particle layer 3
The inorganic particle layer 3 is formed of inorganic fine particles having an average particle diameter in the range of 10 to 100 nm.

  Examples of the inorganic fine particles include alumina fine particles, silica fine particles, titanium fine particles, and calcium carbonate fine particles.

  For the inorganic particle layer, other additives such as a leveling agent, an antifoaming agent, and other additives such as a fluorescent whitening agent and an ultraviolet absorber are added in an amount of 0.01 to 5% by weight based on the total weight of the inorganic particle layer. A degree may be added. Furthermore, in order to improve the coating film stability of the inorganic particle layer, it is also possible to mix a polymer. For example, polyester, urethane, polyvinyl pyrrolidone, polyvinyl alcohol and the like can be widely used. The polymer is preferably added in a range of 5% to 90% with respect to the total weight of the inorganic particle layer. The coating film stability of the inorganic particle layer can be further improved by adding the polymer within the range.

  The inorganic particle layer may contain a resin component. When the resin component is contained in the inorganic particle layer, the adhesion between the release layer, the adhesive layer and the inorganic particle layer can be improved, and the film forming property of the inorganic particle layer itself can be improved. Examples of such resin components include vinyl resins such as polyvinyl alcohol, polyvinyl acetate, polyvinyl butyral, polyvinyl acetal, and polyvinyl pyrrolidone; polymethyl methacrylate, polyethyl acrylate, polyacrylamide, acrylonitrile-styrene copolymer, and the like. An acrylic resin; a polyamide resin; a polyvinyl toluene resin; a coumarone indene resin; a polyester resin; and a polyurethane resin.

The inorganic particle layer is formed by applying a coating solution obtained by dissolving or dispersing fine particles, and if necessary, other additives in a solvent such as an organic solvent or water, on the release layer by a known coating method such as a wire coating method. And formed by drying. The thickness of the inorganic particle layer is about 0.03 to 1 g / m ² , preferably about 0.03 to 0.5 g / m ² .

  Thus, when the inorganic particle layer is laminated on the protective layer thermal transfer sheet, for example, when the protective layer is transferred to an image formed on an image receiving sheet using an aqueous receiving layer containing an aqueous binder resin. Then, even when the printed matter on which the image is formed is sandwiched between the sheets formed with the film or stored in contact with the film, the plasticizer contained in the film penetrates into the aqueous receiving layer. This can be prevented more effectively.

(4) Adhesive layer 4
The adhesive layer 4 becomes an adhesive surface with an image receiving sheet on which an image is formed at the time of thermal transfer, and has a function of expressing good adhesion to various image receiving sheets and protecting the image.

  The adhesive layer 4 in the present invention is characterized by being formed of a resin obtained by copolymerizing methyl methacrylate and a reactive ultraviolet absorber together with the above-described release layer.

Here, as the reactive ultraviolet absorber which can be copolymerized with methyl methacrylate, conventionally known salicylate type, benzophenone type (Chemical Formula 1), benzotriazole type (Chemical Formula 2), substituted acrylonitrile type, nickel chelate type, hindered amine System can be widely used.

  Further, the resin obtained by copolymerizing methyl methacrylate and a reactive ultraviolet absorber is a resin copolymerized at a reactive ultraviolet absorber ratio of 10 to 50% by weight.

  In a resin obtained by copolymerizing methyl methacrylate and a reactive ultraviolet absorbent, if the reactive ultraviolet absorbent ratio is lower than 10%, the print is cracked when stored under high temperature and high humidity, which is not preferable.

  In addition, in a resin obtained by copolymerizing methyl methacrylate and a reactive ultraviolet absorber, if the reactive ultraviolet absorber ratio is higher than 50%, Tg (glass transition temperature) of the copolymerized resin is lowered, and there is a problem in storage stability. Occurs.

  The adhesive layer in the present invention contains additives such as an ultraviolet absorber, an antioxidant, and a fluorescent brightening agent in an amount of 10 to 50% by weight with respect to these resins.

  If the blending ratio of the additive is less than 10% by weight with respect to the resin, cracks occur when the printed product is stored under high temperature and high humidity, which is not preferable.

  If the blending ratio of the additive is more than 50% by weight based on the resin, the scratch resistance of the printed material is lowered, which is not preferable.

  The adhesive layer is an ordinary coating method such as a gravure printing method, a screen printing method, a reverse roll coating method using a gravure plate, or an ink obtained by dissolving or dispersing the above-mentioned resin or other additives in a solvent such as water or an organic solvent. According to the above, it is formed by coating and drying.

  The thickness of the adhesive layer is usually about 0.1 to 10 μm, preferably about 0.5 to 5.0 μm.

(5) Back layer 5
It is preferable to form a back layer made of the following materials on the back surface (the side opposite to the side on which the adhesive layer is formed) of the base material of the protective layer thermal transfer sheet.

  Examples of the resin constituting the back layer 5 include cellulose resins such as ethyl cellulose, hydroxy cellulose, hydroxypropyl cellulose, methyl cellulose, cellulose acetate, cellulose acetate butyrate, and nitrocellulose; polyvinyl alcohol, polyvinyl acetate, polyvinyl butyral, polyvinyl acetal Vinyl resins such as polyvinylpyrrolidone; acrylic resins such as polymethyl methacrylate, polyethyl acrylate, polyacrylamide, and acrylonitrile-styrene copolymers; polyamide resins; polyvinyl toluene resins; coumarone indene resins; polyester resins; Polyurethane resin; natural or synthetic resin such as silicone-modified or fluorine-modified urethane can be used.

  These resins are used singly or in combination of two or more.

  From the viewpoint of further improving the heat resistance of the back layer 5, among the above resins, a resin having a reactive group such as a hydroxyl group (for example, butyral resin, acetal resin, etc.) is used, and a polyisocyanate is used as a crosslinking agent. Etc. are preferably used together to form a crosslinked resin layer.

  Furthermore, for the purpose of imparting slidability with the thermal head, a solid or liquid release agent or lubricant may be blended in the back layer.

  Examples of release agents or lubricants include various waxes such as polyethylene wax and paraffin wax; higher aliphatic alcohols, organopolysiloxanes, anionic surfactants, cationic surfactants, amphoteric surfactants, nonionic surfactants Examples thereof include various surfactants such as an activator and a fluorosurfactant; fine particles of inorganic compounds such as organic carboxylic acids and derivatives thereof, fluororesins, silicone resins, talc, and silica.

  The amount of the lubricant contained in the back layer 5 is usually 5 to 50% by weight, preferably about 10 to 30% by weight in the back layer.

  The back layer 5 is a reverse roll coating using a gravure printing method, a screen printing method, a gravure plate, and an ink obtained by dissolving or dispersing the above resin and other additives in a solvent such as water or an organic solvent on a base sheet. It is formed by applying and drying in accordance with a normal coating method such as a method.

  The thickness of the back layer 5 is usually about 0.1 to 10 μm, preferably about 0.5 to 5 μm.

(Second embodiment)
FIG. 2 is a schematic cross-sectional view showing a protective layer thermal transfer sheet according to the second embodiment.

  As shown in FIG. 2, the protective layer thermal transfer sheet 20 according to the present embodiment includes a base sheet 11 and a release layer 6 (inorganic particle layer 7, adhesive layer 8) and a dye layer 17 in this order.

  The release layer 6, the inorganic particle layer 7, and the adhesive layer 8 are as described in the first embodiment, and description thereof is omitted here.

  The dye layer 17 is composed of dye layers 17Y, 17M, 17C, and 17BK having hues of yellow, magenta, cyan, and black. Such a dye layer 17 (17Y, 17M, 17C, 17BK) contains at least a dye and a binder resin.

  As the dye to be used, any dyes such as azo, azomethine, methine, anthraquinone, quinophthalone, and naphthoquinone that are used in the conventional heat-sensitive sublimation transfer type protective layer thermal transfer sheet can be used. There is no. In addition, a dye having an arbitrary hue such as black can be prepared by combining the above various dyes.

  As the binder resin for supporting the dye in the dye layer 17, any conventionally known binder resin can be used. For example, cellulose resins such as ethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, methyl cellulose, cellulose acetate, cellulose acetate butyrate, Examples include polyvinyl resins such as polyvinyl alcohol, polyvinyl acetate, polyvinyl butyral, polyvinyl acetal, polyvinyl pyrrolidone, polyacrylamide, and polyester. Among these, cellulose, acetal, butyral, and polyester are heat-resistant, dyes It is preferable from the viewpoint of the transferability.

  Further, the dye layer 17 can contain any conventionally known release agent in order to prevent thermal fusion of the dye layer, the binder and the receiving layer resin during printing. Specifically, various waxes such as polyethylene wax and paraffin wax, higher aliphatic alcohols, organopolysiloxanes, various surfactants, various phosphate esters, fluorine-based resins, silicone-based resins, and the like can be used.

  The dye layer 17 is prepared by applying an ink prepared by dissolving or dispersing a sublimable dye as described above and a binder resin added with a necessary additive in an appropriate solvent by a known method. It is formed by drying. The thickness of the dye layer 17 can be set in the range of 0.2 to 5 μm, preferably 0.4 to 2 μm, and the ratio of the sublimable dye in the dye layer 17 is 5 to 90% by weight, preferably 10 to 70% by weight. It is a range.

  In the protective layer thermal transfer sheet 20 described above, the order is 17Y → 17M → 17C → 17BK → release layer 6 (inorganic particle layer 7 and adhesive layer 8), but is not limited thereto. Further, the black dye layer 17BK may be omitted. Further, a part or all of the dye layer 17 (17Y, 17M, 17C, 17BK) may have a two-layer structure in which a functional intermediate layer is provided between the substrate and the dye layer.

  The protective layer thermal transfer sheet of the present invention is not limited to the above-described embodiment, and can be arbitrarily set according to the purpose of use. In particular, by using a composite type protective layer thermal transfer sheet, it is possible to simultaneously perform image formation by the thermal transfer method and transfer of the adhesive layer to the printed material.

<Printed matter>
Next, the printed matter of the present invention will be described.

  FIG. 3 is a schematic cross-sectional view showing the printed material of the present invention. As shown in FIG. 3, the print 30 includes a porous layer 22 containing a water-based binder and hollow particles as main components and a water-based receptive layer 23 on a base material 21, and heat-sensitive sublimation transfer to the water-based receptive layer 23. A protective layer (including a release layer, an inorganic particle layer, and an adhesive layer) 25 is provided so as to cover the image 24 having the image 24 recorded by the method. The image 24 includes a full-color image 24a composed of three colors of yellow, magenta, and cyan, or four colors added with black as necessary, and a monotonous image 24b of characters, symbols, and the like.

  In the printed matter 30 shown in FIG. 3 described above, the entire image 24 is covered with the protective layer 25, but it is sufficient that at least a part of the image 24 is covered.

  Such a printed matter can be created by forming a thermal transfer image on an image receiving sheet shown below using, for example, the protective layer thermal transfer sheet according to the second embodiment.

<Image receiving sheet>
FIG. 4 is a schematic cross-sectional view showing the image receiving sheet of the present invention. As shown in FIG. 4, a porous layer 32 containing at least an aqueous binder and hollow particles, and an aqueous receiving layer 33 mainly composed of an aqueous binder and a release material are laminated on a base material 31. Accordingly, a second functional intermediate layer can be interposed between the base material and the porous layer and between the porous layer and the porous layer.

(Substrate 31)
There is no restriction | limiting in particular as a base material of an image receiving sheet, According to the intended purpose etc., the thing of a various material, layer structure, and a size can be selected and used suitably. For example, various papers such as paper, coated paper, and synthetic paper (polypropylene, polystyrene, or a composite material obtained by laminating them with paper), a vinyl chloride resin sheet, an ABS resin sheet, a polyethylene terephthalate (PET) base film, Polybutylene terephthalate base film, polyethylene naphthalate (PEN) base film, polyarylate base film, polycarbonate base film, polyether ether ketone base film, polysulfone base film, polyether sulfone base film, polyetherimide base film, polyimide base film Or various plastic films or sheets in which they are laminated in two or more layers, films or sheets formed of various metals, various ceramics It can be mentioned composite materials were appropriately combined laminate from those formed by the class film or sheet or the forth, or the like.

(Porous layer 32)
Examples of the hollow particles contained in the porous layer 32 formed on the substrate 31 include thermally expandable hollow particles and capsule-shaped hollow polymers as the hollow particles constituting the porous layer 32. Thermally expandable hollow particles are hollow particles whose wall material is a thermoplastic material such as vinylidene chloride-acrylonitrile copolymer, and a material containing a thermally expandable gas such as propane, n-butane, isobutane, etc. inside the particles. is there. The capsule-like hollow polymer is a hollow polymer having a wall material made of a resin such as styrene-acrylic resin or melamine resin. The hollow particles as described above generally have a particle size of about 0.1 to 100 μm, but in the present invention, hollow particles having a particle size of about 0.1 to 50 μm are preferably used. If the thickness is less than 0.1 μm, a sufficient heat insulating effect as a hollow particle cannot be obtained, and if it exceeds 50 μm, the smoothness is significantly lowered.

  Examples of the water-based binder used for the porous layer 32 include polyester resins, polyacrylate resins, polycarbonate resins, polyvinyl acetate resins, styrene acrylate resins, and the like; polyurethane resins having amide bonds; amide bonds As for having a polyamide resin (nylon); As for having a urea bond, a urea resin; Furthermore, as having another highly polar bond, polycaprolactone resin, polystyrene resin, polyvinyl chloride, polyacrylonitrile resin May be used, or may be used as a copolymer mainly composed of one or more of the structural units of the resin, for example, vinyl chloride-vinyl acetate copolymer, styrene-butadiene copolymer, etc. In addition, the above resins can be used alone or in combination It can be.

  In addition, vinyl polymers such as water-soluble polyvinyl alcohol, polyvinyl pyrrolidone, cation-modified polyvinyl alcohol and derivatives thereof, polyacrylamide, polydimethylacrylamide, polydimethylaminoacrylate, polyacrylic acid or salts thereof, acrylic acid-methacrylic acid copolymer Combined or salt thereof, polymethacrylic acid or salt thereof, acrylic group-containing polymer such as acrylic acid-vinyl alcohol copolymer or salt thereof, starch, oxidized starch, starch acetate, carboxyl starch, dialdehyde starch, cationic starch, gelatin , Dextrin, sodium alginate, gum arabic, casein, pullulan, dextran, and other natural polymers or derivatives thereof, maleic acid-vinyl acetate copolymer, maleic acid-N-vinyl pyrrole Emissions copolymer, maleic acid - alkyl vinyl copolymers, synthetic polymers such as polyethylene imine, can be also used.

  Colored pigments, white pigments, and the like can be used for the porous layer 32 as necessary. Specific examples of white pigments include barium sulfate, titanium dioxide (rutile type and anatase type), zinc sulfide, and calcium carbonate. , Magnesium oxide, various silicates, aluminum oxide, titanium phosphate, satin white, talc, clay and the like. In particular, from the viewpoint of high whiteness, barium sulfate, titanium dioxide, calcium carbonate and the like are preferably used. Further, an antistatic agent, a fluorescent brightening agent, a wetting agent, an antifoaming agent, a dispersing agent, an ultraviolet absorber, a light stabilizer and the like may be added as necessary.

  The porous layer 32 is prepared by dispersing or dissolving an aqueous binder, hollow particles, and other additives to be added in water or an aqueous solution to prepare an aqueous coating liquid. The aqueous coating liquid is applied to the surface of the support. It can be produced by a coating method that is applied and dried.

  When preparing an aqueous coating solution, it is desirable to dissolve or disperse the resin in water according to the solubility or dispersibility of the aqueous binder in water. Moreover, depending on the case, you may use together the alcohol solvent which mixes with water, acetone, a dioxane, etc. in the ratio of 20 weight% or less with respect to 100 weight% of water.

  The coating liquid for forming a porous layer prepared as described above is applied and dried on the substrate using a known coating method such as an extrusion coating method, a wire bar coating method, or a roll coating method. The thickness of the porous layer comprising the above components can be appropriately provided in the range of 20 to 80 μm.

(Water-based receiving layer 33)
The aqueous receptive layer binder used for the aqueous receptive layer 33 mainly composed of an aqueous binder and a release material has a dyeing property with respect to the heat diffusible dye, and is an aqueous receptive layer forming coating liquid described later. Since it uses for preparation, what has the favorable solubility or dispersibility with respect to water is preferable.

Examples of such binders include polyvinyl chloride resins, copolymer resins of vinyl chloride and other monomers (isobutyl vinyl ether, vinyl propionate, etc.), polyester resins, poly (meth) acrylic acid, poly (meth) acrylic acid. Esters, polyvinyl pyrrolidone, polyvinyl acetal resins, polyvinyl alcohol, polycarbonate, cellulose triacetate, polystyrene, copolymers of styrene and other monomers (acrylic ester, acrylonitrile, ethylene chloride, etc.), ethylene and other monomers (acetic acid Vinyl, acrylate ester, etc.), vinyl toluene acrylate resin, polyurethane resin, polyamide resin, urea resin, epoxy resin, phenoxy resin, polycaprolactone resin, polyacrylonitrile resin, methyl Cellulose resins such as cellulose, may be mentioned gelatin, starch, casein and a modified product thereof.

Among the above-mentioned resins, polyvinyl chloride resin, copolymers of vinyl chloride and other monomers, polyvinyl acetal resins, copolymers of styrene and other monomers, polyester resins, and epoxy resins are preferable.

These resins can be used alone or in combination of two or more.

  The release agent used in combination with the binder includes silicone oil (including those called silicone resins); solid waxes such as polyethylene wax, amide wax, Teflon (registered trademark) powder; fluorine-based, phosphate ester-based In particular, silicone oil is preferable. This silicone oil is classified into a type that is simply added and a type that is cured or reacted.

  As a type to be simply added, in order to improve the compatibility with the resin, modified silicone oil (polyester modified silicone oil, polyether modified silicone oil, polyester modified silicone oil, urethane modified silicone oil, acrylic modified silicone oil, Alcohol-modified silicone oil, amide-modified silicone oil, etc.) are preferably used.

The amount of these silicone oils to be added varies depending on the type and cannot be determined uniformly, but is generally 0.1 to 50% by weight based on the binder for the receiving layer. It is preferably 0.5 to 20% by weight.

  Examples of the curing reaction type silicone oil include a thermosetting type, a photocuring type, and a catalyst curing type.

  The addition amount of these curable silicone oils is preferably 0.5 to 30% by weight of the receptor layer binder.

  The aqueous receiving layer 33 is prepared by dispersing or dissolving a resin, a release material, and other additives that are added as necessary in water or an aqueous solution to prepare an aqueous coating solution. When preparing an aqueous coating solution, it is desirable to dissolve or disperse the resin in water according to the solubility or dispersibility of the receptor layer binder in water. Moreover, depending on the case, you may use together the alcohol solvent which mixes with water, acetone, a dioxane, etc. in the ratio of 20 weight% or less with respect to 100 weight% of water.

  That is, in order to prepare this aqueous coating solution, a water-soluble resin in which the binder is well dissolved in water (water-soluble polyvinyl acetal resin, water-soluble polyester, polyvinyl alcohol, starch, casein, gelatin, polyacrylic acid, etc.) If so, if it is an emulsion resin (polyvinyl chloride resin, styrene-butadiene copolymer, etc.) formed by solution polymerization using water or a solvent as a binder, the binder is suitably used. Suspension resin (epoxy resin, copolymer of vinyl chloride and other monomers, etc.) dispersed in water by suspending in water or aqueous solution together with surfactant or by using a dispersant as the binder If this is the case, use a dispersing agent to remove water or an aqueous solution using a known dispersing machine such as an attritor, ball mill, or sand grinder. It is dispersed desirably.

These coating liquids can be used together as appropriate, and emulsion resins and dispersion resins are commercially available suspensions (vinyl chloride latex, styrene-butadiene latex, ethylene-vinyl acetate latex from the beginning). , Water-dispersed polymer polyester, etc.) or a dispersion.

  The aqueous receptive layer-forming coating solution prepared as described above is applied and dried on the porous layer using a known coating method such as extrusion coating, wire bar coating, or roll coating. . The thickness of the water-based receiving layer comprising the above components can be appropriately provided in the range of 0.5 to 10 μm.

  Hereinafter, the present invention will be described by way of examples. In the examples, “parts” or “%” are based on weight unless otherwise specified.

[Example 1]
On the 6 μm thick polyethylene terephthalate film (Toray Industries, Inc., easy-adhesion treated product), the back layer ink having the following composition was applied by gravure coating (coating amount 1.0 g / m ² (when dry)) and dried. Thereafter, a curing process was performed to form a back layer.

  Next, on the surface opposite to the surface on which the back layer is formed, a release layer ink having the following composition is applied by a gravure coating method, dried, a release layer is formed, and an inorganic particle having the following composition is formed by a wire coating method. Layer ink was applied and dried to form an inorganic particle layer. Next, an adhesive layer ink having the following composition was applied thereon and dried by a gravure coating method to form an adhesive layer having a thickness of 0.6 μm, and a protective layer thermal transfer sheet of Example 1 was produced.

(Back layer ink)
Polyvinyl butyral (Sekisui Chemical Co., Ltd. ESREC BX-1) 15 parts Polyisocyanate (Dainippon Ink Chemical Co., Ltd. Barnock D450) 35 parts Phosphate ester surfactant (Daiichi Kogyo Seiyaku Co., Ltd. Prisurf) A208S) 10 parts Talc (Nihon Talc Co., Ltd. Microace P-3) 3 parts

(Ink for adhesive layer 1)
Resin Methyl methacrylate and benzotriazole (reactive UV absorber) copolymer (MMA + UV absorber (RUVA-93 manufactured by Otsuka Chemical Co., Ltd.) copolymer 18 parts Reactive UV absorber ratio in the above copolymer = 30%
・ Additives (UV absorbers)
(Ciba Specialty Chemicals Co., Ltd. Tinuvin 928) 1.5 parts Additive (ultraviolet absorber) ratio to resin (solid content) = 20%
・ Solvent 9 parts ethyl acetate

(Ink for inorganic particle layer 1)
・ Alumina sol (Alumina sol 200 manufactured by Nissan Chemical Industries, Ltd.) 50 parts ・ Water 25 parts ・ IPA 25 parts

(Ink for release layer 1)
Resin Methyl methacrylate and benzotriazole (reactive UV absorber) copolymer (MMA + UV absorber (RUVA-93 manufactured by Otsuka Chemical Co., Ltd.) copolymer 18 parts Reactive UV absorber ratio in the above copolymer = 30%
・ Additives (UV absorbers)
(Ciba Specialty Chemicals Co., Ltd. Tinuvin 928) 1.5 parts Additive (ultraviolet absorber) ratio to resin (solid content) = 20%
・ Solvent 9 parts ethyl acetate

[Example 2]
A protective layer thermal transfer sheet of Example 2 was produced in the same manner as in Example 1 except that the inorganic particle layer ink was changed to the following.

(Layer ink 2 for inorganic particles)
・ Silica sol (IPA-ST manufactured by Nissan Chemical Industries, Ltd.) 50 parts ・ Water 25 parts ・ IPA 25 parts

[Example 3]
A protective layer thermal transfer sheet of Example 3 was produced in the same manner as in Example 1 except that the inorganic particle layer ink was changed to the following.

(Ink for inorganic particle layer 3)
・ Alumina sol (Alumina sol 200 manufactured by Nissan Chemical Industries, Ltd.) 25 parts ・ Silica sol (IPA-ST manufactured by Nissan Chemical Industries, Ltd.) 25 parts ・ Water 25 parts ・ IPA 25 parts

[Example 4]
A protective layer thermal transfer sheet of Example 4 was produced in the same manner as in Example 3 except that the adhesive layer ink was changed to the following.

(Adhesive layer ink 2)
Resin Methyl methacrylate and benzotriazole (reactive UV absorber) copolymer (MMA + UV absorber (RUVA-93 manufactured by Otsuka Chemical Co., Ltd.) copolymer) Synthesis solid content (42%)) 18 parts Reactive UV absorber ratio in the above copolymer = 10%
・ Additives (UV absorbers)
(Ciba Specialty Chemicals Co., Ltd. Tinuvin 928) 1.5 parts Additive (ultraviolet absorber) ratio to resin (solid content) = 20%
・ Solvent 9 parts ethyl acetate

[Example 5]
A protective layer thermal transfer sheet of Example 5 was produced in the same manner as in Example 4 except that the adhesive layer ink was changed as follows.

(Adhesive layer ink 3)
Resin Methyl methacrylate and benzotriazole (reactive UV absorber) copolymer (MMA + UV absorber (RUVA-93 manufactured by Otsuka Chemical Co., Ltd.) copolymer) Synthesis solid content (42%)) 18 parts Reactive UV absorber ratio in the above copolymer = 50%
・ Additives (UV absorbers)
(Ciba Specialty Chemicals Co., Ltd. Tinuvin 928) 1.5 parts Additive (ultraviolet absorber) ratio to resin (solid content) = 20%
・ Solvent 9 parts ethyl acetate

[Example 6]
A protective layer thermal transfer sheet of Example 6 was produced in the same manner as in Example 3 except that the adhesive layer ink was changed to the following.

(Adhesive layer ink 4)
Resin Methyl methacrylate and benzotriazole (reactive UV absorber) copolymer (MMA + UV absorber (RUVA-93 manufactured by Otsuka Chemical Co., Ltd.) copolymer 18 parts Reactive UV absorber ratio in the above copolymer = 30%
・ Additives (UV absorbers)
(Tinubin 928 manufactured by Ciba Specialty Chemicals Co., Ltd.) 0.7 parts Additive (ultraviolet absorber) ratio to resin (solid content) = 10%
・ Solvent 9 parts ethyl acetate

[Example 7]
A protective layer thermal transfer sheet of Example 7 was produced in the same manner as in Example 3 except that the adhesive layer ink was changed to the following.

(Adhesive layer ink 5)
Resin Methyl methacrylate and benzotriazole (reactive UV absorber) copolymer (MMA + UV absorber (RUVA-93 manufactured by Otsuka Chemical Co., Ltd.) copolymer 18 parts Reactive UV absorber ratio in the above copolymer = 30%
・ Additives (UV absorbers)
(Tinubin 928 manufactured by Ciba Specialty Chemicals Co., Ltd.) 3 parts Additive (ultraviolet absorber) ratio to resin (solid content) = 40%
・ Solvent 9 parts ethyl acetate

[Example 8]
A protective layer thermal transfer sheet of Example 8 was produced in the same manner as in Example 1 except that the inorganic particle layer ink was changed to the following.

(Ink for inorganic particle layer 4)
・ Alumina sol (Nissan Chemical Industry Co., Ltd. Alumina Sol 200) 25 parts ・ Polyvinylpyrrolidone (Nippon Shokubai K-90) 25 parts ・ Water 25 parts ・ IPA 25 parts

[Comparative Example 1]
A protective layer thermal transfer sheet of Comparative Example 1 was produced in the same manner as in Example 4 except that the adhesive layer ink was changed to the following.

(Adhesive layer ink 6)
Resin Methyl methacrylate and benzotriazole (reactive UV absorber) copolymer (MMA + UV absorber (RUVA-93 manufactured by Otsuka Chemical Co., Ltd.) copolymer) Synthesis solid content (42%)) 18 parts Reactive UV absorber ratio in the above copolymer = 5%
・ Additives (UV absorbers)
(Ciba Specialty Chemicals Co., Ltd. Tinuvin 928) 1.5 parts Additive (ultraviolet absorber) ratio to resin (solid content) = 20%
・ Solvent 9 parts ethyl acetate

[Comparative Example 2]
A protective layer thermal transfer sheet of Comparative Example 2 was produced in the same manner as in Example 4 except that the adhesive layer ink was changed as follows.

(Adhesive layer ink 7)
Resin Methyl methacrylate and benzotriazole (reactive UV absorber) copolymer (MMA + UV absorber (RUVA-93 manufactured by Otsuka Chemical Co., Ltd.) copolymer) Synthesis Solid content (42%)) 18 parts Reactive UV absorber ratio in the above copolymer = 60%
・ Additives (UV absorbers)
(Ciba Specialty Chemicals Co., Ltd. Tinuvin 928) 1.5 parts Additive (ultraviolet absorber) ratio to resin (solid content) = 20%
・ Solvent 9 parts ethyl acetate

[Comparative Example 3]
A protective layer thermal transfer sheet of Comparative Example 3 was produced in the same manner as in Example 3 except that the adhesive layer ink was changed to the following.

(Adhesive layer ink 8)
Resin Methyl methacrylate and benzotriazole (reactive UV absorber) copolymer (MMA + UV absorber (RUVA-93 manufactured by Otsuka Chemical Co., Ltd.) copolymer) Synthesis) 18 parts Reactive UV absorber ratio in the above copolymer = 30%
・ Additives (UV absorbers)
(Tinubin 928 manufactured by Ciba Specialty Chemicals Co., Ltd.) 0.3 part Additive (ultraviolet absorber) ratio to resin (solid content) = 5%
・ Solvent 9 parts ethyl acetate

[Comparative Example 4]
A protective layer thermal transfer sheet of Comparative Example 4 was produced in the same manner as in Example 3 except that the adhesive layer ink was changed as follows.

(Adhesive layer ink 9)
Resin Methyl methacrylate and benzotriazole (reactive UV absorber) copolymer (MMA + UV absorber (RUVA-93 manufactured by Otsuka Chemical Co., Ltd.) copolymer) Synthesis) 18 parts Reactive UV absorber ratio in the above copolymer = 30%
・ Additives (UV absorbers)
(Tinubin 928, manufactured by Ciba Specialty Chemicals Co., Ltd.) 3.8 parts Additive (ultraviolet absorber) ratio to resin (solid content) = 51%
・ Solvent 9 parts ethyl acetate

[Comparative Example 5]
A protective layer thermal transfer sheet of Comparative Example 5 was produced in the same manner as in Example 1 except that the inorganic particle layer was not laminated.

[Comparative Example 6]
A protective layer thermal transfer sheet of Comparative Example 6 was produced in the same manner as in Example 1 except that the adhesive layer ink was changed as follows.

(Adhesive layer ink 10)
Resin Polyester resin (byron 700 manufactured by Toyobo Co., Ltd.) 20 parts methyl methacrylate and benzotriazole (reactive UV absorber) copolymer (MMA + UV absorber (RUVA-93 manufactured by Otsuka Chemical Co., Ltd.)) 5.4 parts reactive UV absorber ratio in the above copolymer = 50%
MEK / toluene = 1/1 38 parts Reactive ultraviolet absorber ratio in the resin = 10%
・ Additives (UV absorbers)
(Cinubin 900 manufactured by Ciba Specialty Chemicals Co., Ltd.) 5.3 parts Additive (UV absorber) ratio to resin (solid content) = 20%
・ Solvent MEK 5 parts Toluene 5 parts

[Comparative Example 7]
A protective layer thermal transfer sheet of Comparative Example 7 was produced in the same manner as in Example 1 except that the release layer ink was changed as follows.

(Ink for release layer 2)
・ Resin LP45M
(Thermo rack LP-45M, manufactured by Soken Chemical Co., Ltd.) 20 parts, additive (ultraviolet absorber)
(UVITEX OB manufactured by Ciba Specialty Chemicals Co., Ltd.) 0.02 parts ・ Solvent MEK 40 parts Toluene 40 parts

  Next, each protective layer thermal transfer sheet of Examples and Comparative Examples was printed on a water-based image-receiving sheet prepared as described below by a thermal printer head under the same printing conditions as described below to form an image. Evaluation, crack evaluation, and scratch resistance evaluation were performed.

Aqueous image-receiving sheet RC paper (STF-150, manufactured by Mitsubishi Paper Industries Co., Ltd.) is used as a base sheet, and a porous layer forming coating solution and a receiving layer forming coating solution having the following compositions are heated to 50 ° C., respectively. Using a slide coating, the thickness when dried is 30 μm and 5 μm, respectively, cooled and gelled at 5 ° C. for 1 minute, dried at 50 ° C. for 5 minutes, and a thermal transfer image receiving sheet (image receiving paper) )

<Porous layer forming coating solution>
・ Hollow particles (HP-91 Rohm and Haas) (as solid content) 70 parts ・ Gelatin (RR Nitta Gelatin Co., Ltd.) (as solid content) 30 parts ・ Interface slip material (Surfinol 440 Nissin Chemical Industry) 0.15 parts

<Coating liquid for forming receiving layer>
・ Emulsion (as solids) 70 parts ・ Resin filler (VB900) (as solids) 15 parts ・ Gelatin (RR Nitta Gelatin Co., Ltd.) (as solids) 15 parts ・ Silicone mold release agent (Surfinol 440) Shin-Etsu Chemical Co., Ltd.) 10 parts ・ Interface slip material (Surfinol 440 Nissin Chemical Industry Co., Ltd.) 1 part

  For the synthesis of the emulsion of the coating solution for forming the receiving layer, in a 500 mL Erlenmeyer flask, 103 g of styrene, 54 g of ethyl acrylate, 41 g of lauryl acrylate, 2 g of acrylic acid, emulsifier (AQUALON HS-10 Daiichi Kogyo Seiyaku Co., Ltd.) 1 .9 g was added and stirred and mixed (hereinafter referred to as monomer A). In a 1 L three-necked flask, 200 g of distilled water was added and heated to 80 ° C., and about 20% of the total amount of monomer A was added and stirred for 10 minutes. Thereafter, 0.2 g of ammonium persulfate dissolved in 20 g of pure water was added and stirred for 10 minutes, and then the remaining 80% of the monomer A was dropped with a dropping funnel over 3 hours and further stirred for 3 hours. Thereafter, the mixture was cooled to room temperature and filtered through # 150 mesh (Japanese woven fabric) to obtain an emulsion. Molecular weight 242273, Tg 50 ° C. Further, from the molecular weight of styrene, ethyl acrylate and lauryl acrylate and the amount used for the reaction, the respective molar ratios are 58%, 32% and 10%.

The resin filler is a vinyl chloride-ethyl acrylate copolymer (monomer blending ratio is 90% vinyl chloride, 10% ethyl acrylate in mol ratio), Tg 70 ° C. (VB900
Nissin Chemical Industry Co., Ltd.) was used.

Printing condition thermal head: KGT-217-12MPL20 (manufactured by Kyocera Corporation)
Heating element average resistance: 2994 (Ω)
Main scanning direction printing density; 300 dpi
Sub-scanning direction print density; 300 dpi
Applied power: 0.10 (w / dot)
1 line cycle: 5 (msec.)
Printing start temperature; 40 (° C)
Applied pulse (gradation control method); using a multi-pulse test printer that can vary the number of divided pulses from 0 to 255 in one line period and having a pulse length obtained by equally dividing one line period into 256 The duty ratio of the divided pulses was fixed to 70%, and the number of pulses per line period was divided into 15 from 0 to 255. Thereby, different energy can be given to 15 steps. This time, only the largest energy of 15 different energy levels was used for printing.
Print pattern: Solid black

  The image printed on the aqueous image-receiving sheet was subjected to glossiness evaluation, crack evaluation, plasticizer resistance evaluation, storage stability (scratch resistance evaluation), and blocking resistance evaluation. The results are also shown in Table 1. In Table 1, the criteria for glossiness evaluation, crack evaluation, plasticizer resistance evaluation, storage stability (abrasion resistance evaluation), and blocking resistance evaluation were as follows.

<Evaluation>
Glossiness Solid black was printed and measured at a measurement angle of 45 ° using Gloss Meter VG2000 (Nippon Denshoku).
A glossiness of less than 80 was evaluated as x, and 80 or more was evaluated as ◯.
-Cracks An evaluation pattern was printed and stored in an atmosphere of 40 ° C and 90%. The surface condition after storage for 100 hours was visually observed.
When there was a crack, it evaluated as x, and when there was no crack, it evaluated as (circle).
-Plasticizer resistance A sample was cut and pasted on the protective sheet portion of the current ribbon, black solids were printed, a polyvinyl chloride sheet was brought into contact with the printing screen, and stored under a pressure of 40 g / cm ^{2 in} a 50 ° free environment. After storage, the PVC sheet was peeled off, and it was visually judged whether or not the dye was taken on the PVC sheet side.
The case where the degree of dye removal was severe was evaluated as x, and the others were evaluated as o.
・ Storage (scratch resistance)
The print was subjected to a 200-rotation wear test with a Taber tester equipped with a wear wheel CS-10, and the state of the image of the print was visually observed and evaluated according to the following criteria.
A: The image is not affected at all.
○: The image starts to be affected by wear, but is hardly noticeable.
Δ: Some wear is confirmed.
×: considerably worn.
-Blocking resistance The protective layer and the back layer were overlapped, a pressure of 5 kgf / cm ² was applied, and the mixture was allowed to stand at 50 ° C. for 48 hours.
After storage, the protective layer and the back layer were peeled off, and the presence or absence of blocking was evaluated from the ease of peeling.
○: No blocking (the protective layer and the back layer can be easily removed)
X: Blocking (the protective layer and the back layer are stuck and cannot be easily removed)

<Results and discussion>
As shown in Table 1, in Examples 1 to 8, good results were obtained in all of glossiness, cracking, plasticizer resistance, storage stability (abrasion resistance), and blocking resistance.

  On the other hand, in Comparative Examples 1 and 2, since the ratio of the reactive ultraviolet absorber in the resin is not 10 to 50% by weight as compared with Examples, Comparative Example 1 is cracked, and Comparative Example 2 is The plasticizer resistance and blocking resistance were poor. In Comparative Examples 3 and 4, since the additive ratio is not 10 to 50% by weight as compared with Examples, Comparative Example 3 is cracked, and Comparative Example 4 is plasticizer resistance and storage stability. (Abrasion resistance) was a bad result. In Comparative Example 5, since the inorganic particle layer was not laminated as compared with the Example, the plasticizer resistance was poor, and in Comparative Example 6, the adhesive layer was methyl methacrylate as compared with the Example. Since it is not formed of a resin obtained by copolymerizing a reactive ultraviolet absorber, cracking occurs, resulting in poor plasticizer resistance. In Comparative Example 7, the release layer reacted with methyl methacrylate as compared with the Example. Since it was not formed with a resin copolymerized with a curable ultraviolet absorber, the glossiness was poor and cracking occurred.

DESCRIPTION OF SYMBOLS 1, 11 ... Base material sheet 2, 6 ... Release layer 3, 7 ... Inorganic particle layer 4, 8 ... Adhesive layer 5 ... Back layer 25 ... Protective layer 17 ... Dyeing layer 21, 31 ... Base material 22, 32 ... Porous layer 23, 33 ... Aqueous receiving layer 24 ... Image 10, 20 ... Protective layer thermal transfer sheet 30 ... Printed matter 40 ... Image receiving sheet

Claims (2)

  A protective layer thermal transfer sheet obtained by laminating a release layer, an inorganic particle layer, and an adhesive layer in this order on a substrate sheet, and the release layer and the adhesive layer are both methyl methacrylate and a reactive ultraviolet absorber, A protective layer thermal transfer sheet, which is formed of a resin copolymerized at a reactive ultraviolet absorber ratio of 10 to 50% by weight and contains an additive at a ratio of 10 to 50% by weight with respect to the resin. A printed material comprising a porous layer containing a water-based binder and hollow particles as main components on a substrate, a water-based receiving layer, and a protective layer formed so as to cover at least a part of the water-based receiving layer,
The printed matter, wherein the protective layer is formed by transfer using the protective layer thermal transfer sheet according to claim 1.

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