JPH07290848A - Thermal transfer sheet - Google Patents

Abstract

PURPOSE:To integrally form a protective layer capable of forming a gradation image and a monotonous image at the same time by providing a colorant layer region of one color and a transfer protective layer region on one surface of a base material sheet in surface sequence and providing the transfer protective layer region so as to be capable of releasing an ionizing radiation curable resin layer. CONSTITUTION:A sublimable dye layer region 2 consisting of sublimable dye layers 2Y, 2M, 2C containing yellow, magenta and cyan dyes, a hot-melt ink layer region 3 and a transfer protective layer region 4 are formed on a base material sheet 1 in surface sequence. In the transfer protective layer region 4, a release layer 5 is laminated on the side of the base material sheet 1 and an ionizing radiation curable resin 6 is provided in a releasable manner by the release layer 5 and an adhesive layer 7 is laminated and formed on the ionizing radiation curable resin layer 6. By this constitution, a protective layer capable of forming a gradation image and a monotonous image can be integrally formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal transfer sheet in which a protective layer and a color material layer are provided on a substrate in a frame-sequential manner. More specifically, like a ID card, a photographic image and characters and symbols are simultaneously included. The present invention relates to a thermal transfer sheet capable of forming an image having excellent durability on a printed matter.

[0002]

2. Description of the Related Art Conventionally, various thermal transfer methods are known,
Among them, a transfer sheet in which a dye layer containing a sublimable dye and a binder is provided on a substrate film is used, and the dye in the dye layer is sublimated (heated by a heating means such as a thermal head or laser according to image information). A sublimation type thermal recording method is known in which recording is performed after the transfer. In addition, a transfer sheet having a heat-fusible ink layer containing a colorant such as a pigment and a vehicle such as a wax on a substrate film is used, and the softened ink layer component softened by the same heating means is transferred to form an image. A heat-melting type heat-sensitive recording method for forming is known.
Since various images can be easily formed by these thermal transfer methods, they are used for producing printed matters such as ID cards, which require a relatively small number of printed sheets. .

When an ID card such as an identification card is produced using the thermal transfer sheet as described above, a monotonous image such as letters and numbers can be easily formed when the thermal fusion type thermal transfer sheet is used. However, there is a drawback that it is difficult to form a gradation image such as a facial photograph. On the other hand, when a sublimation transfer type thermal transfer sheet is used, on the contrary, a gradation image such as a facial photograph is excellent, but an image such as a character or a symbol lacks density and sharpness, and an OCR readable by infrared rays is used. Characters, barcodes, etc. cannot be formed, so that a satisfactory image cannot be formed. In order to solve such a problem, there is a method of using the above-mentioned fusion type transfer sheet and sublimation type transfer sheet together. However, this method has a drawback that the operation is complicated. A thermal transfer sheet has been developed in which a sublimation type dye layer and a melting type ink layer are provided in a surface-sequential manner on a base film. With such a thermal transfer sheet, a gradation image such as a face photograph and a monotone image such as characters and symbols are favorably formed. For example, in an application such as an ID card where various durability, especially abrasion resistance is required. Then, there is a problem that the durability of the image is insufficient. As a method for solving such a problem, a method of laminating a transparent film on the formed image surface has been carried out, but this method involves two steps and is complicated, and at the same time, it is laminated on the entire card. Therefore, there is a problem that even unnecessary portions are laminated, and further, a thin film cannot be used due to the operation of laminating, so that there is a problem that the entire card becomes thick. As a method for solving such a problem, Japanese Patent Laid-Open No. 3-4
No. 5390 discloses a protective layer-integrated thermal transfer sheet in which a sublimable dye layer of at least one color, a heat-fusible ink layer of at least one color, and a transferable protective layer are sequentially provided on a base film. .

[0004]

However, since the protective layer described in the above publication is inferior in durability such as abrasion resistance and plasticizer resistance, even if the protective layer is formed on the corner image,
When the image on which the protective layer is transferred is brought into contact with a vinyl case or the like, it is affected by the plasticizer contained in the vinyl case, or when it comes into contact with a chemical or the like, the image may be missing or the image may be blurred. there were. Therefore, an object of the present invention is to solve the above-mentioned problems of the prior art and to integrally form a protective layer capable of simultaneously forming a grayscale image and a monotone image excellent in durability, particularly plasticizer resistance, by a simple operation. To provide a heat transfer sheet.

[0005]

The above problems can be achieved by the present invention described below. That is, the present invention provides a thermal transfer sheet in which a color material layer region of at least one color and a transferable protective layer region are provided in a surface-sequential manner on one surface of a substrate sheet,
The thermal transfer sheet is characterized in that the transferable protective layer region is provided with an ionizing radiation curable resin layer in a peelable manner.

[0006]

Use of a thermal transfer sheet in which a sublimable dye layer region and / or a heat-fusible ink layer region is provided on a substrate sheet, and a transferable protective layer region made of an ionizing radiation resin is provided on the same plane This makes it possible to obtain an excellent gradation image in the sublimable dye layer area and easily obtain a monotone image such as letters and numbers in the heat-meltable ink layer area. Further, by transferring a protective layer made of an ionizing radioactive resin onto the image formed at the same time, a transferred image having excellent plasticizer resistance, chemical resistance, abrasion resistance and the like can be obtained. Also, by forming the heat-meltable ink layer region from the base sheet side in the order of the release layer, the peeling protection layer, and the heat-meltable ink layer, characters and images with excellent durability such as abrasion resistance can be formed. Can be formed. Furthermore, by providing a layer containing a resin in which a reactive ultraviolet absorber is reactively bonded between the ionizing radiation curable resin layer and the adhesive layer in the transferable protective layer region, the conventional organic ultraviolet absorber has the drawbacks. Because it is difficult for vaporization, diffusion and decomposition due to heat of a certain ultraviolet absorber to occur,
As a result of being able to maintain the ultraviolet absorbing effect for a long period of time, it is possible to form an image having excellent light resistance.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will now be described more specifically with reference to the accompanying drawings, which schematically show preferred embodiments.
FIG. 1 is a diagram schematically showing a cross section of a thermal transfer sheet according to a preferred embodiment of the present invention, and FIG. 4 is a plan view thereof. The thermal transfer sheet of this example has a sublimable dye layer 2 containing yellow, magenta, and cyan dyes on a substrate sheet 1.
A sublimable dye layer region 2 made of Y, 2M, and 2C, a hot-melt ink layer region 3, and a transferable protective layer region 4 are formed in a frame order. In FIG. 2, the transferable protective layer region 4
In order to improve the transferability of the protective layer, the release layer 5, the ionizing radiation curable resin layer 6,
It is characterized in that the adhesive layer 7 is formed. On the other hand, FIG. 3 is a diagram schematically showing a cross section of a thermal transfer sheet of another preferred embodiment. In this embodiment, the heat-meltable ink layer region 3 is characterized by being composed of a release layer 8, a peeling protection layer 9 and a heat-meltable ink layer 10 which are sequentially laminated on the surface of the base material sheet. When the heat-meltable ink layer region 3 is heated by a thermal head to form an image on the surface of the transfer target, the heat-meltable ink layer region 3 is located at the interface between the release layer 8 and the peeling protection layer 9 or the peeling protection layer. 9 and the heat-fusible ink layer 10 is transferred onto the transfer target together with all or part of the peeling protection layer 9 so that the peeling protection layer is positioned on the image surface formed of the formed ink layer. Become.

Reference numeral 11 in the drawing denotes a heat resistant slipping layer, which has the function of preventing sticking of the thermal head of the printer. Further, 12 is a primer layer, which has the function of improving the adhesion of the sublimable dye layer region 2 and the release layers 5 and 8 to the base sheet 1. FIG. 5 has the heat-fusible ink layer region 3 which is the characteristic of FIG. 3, and further, in the transferable protective layer region 4, an ultraviolet blocking layer 13 is provided between the ionizing radiation curable resin layer 6 and the adhesive layer 7. It is provided.

Next, the thermal transfer sheet of the present invention will be described in more detail by the materials used and the forming method. The substrate sheet 1 used in the thermal transfer sheet of the present invention may be any one as long as it has a conventionally known degree of heat resistance and strength, for example, 0.5 to 50 μm, preferably about 3 to 10 μm. Thickness paper, various processed papers, polyester film including polyethylene terephthalate film, polystyrene film, polypropylene film, polysulfone film, polyphenylene sulfide film, polyethylene naphthalate film,
1,4-polycyclohexylene dimethyl terephthalate film, aramid film, polycarbonate film, polyvinyl alcohol film, cellophane and the like, and particularly preferred is polyester film.
These substrate sheets may be single-wafer type or continuous film and are not particularly limited. Of these, a polyethylene terephthalate film is particularly preferable, and it is also preferable to provide an adhesive layer (primer layer 12) on one or both surfaces of the film, if necessary.

On the surface of the above-mentioned substrate on which the color material layer is not provided (rear side), the thermal transfer sheet of the present invention is wound in a roll shape in addition to preventing fusion of the thermal head and improving running property. In order to prevent the back surface and the adhesive layer surface from adhering to each other, it is desirable to provide the heat resistant slipping layer 11 having heat resistant slipperiness and releasability on the back surface side of the base film. Such a heat resistant slipping layer is formed of a release agent such as a curable silicone oil, a curable silicone wax, a silicone resin, a fluororesin or an acrylic resin. Also,
As the heat resistant slipping layer, a thermoplastic resin having an —OH group or a —COOH group, a compound having two or more amino groups, or a compound obtained by reacting diisocyanate or triisocyanate to crosslink and cure may be used. Further, slipperiness can be further improved by adding a phosphoric ester type surfactant or a filler having a crushing property such as talc or mica to the heat resistant slipping layer.

The sublimable dye layer 2 provided on the thermal transfer sheet of the present application is a layer in which a dye is carried by an arbitrary binder. The dye to be used is a dye that melts, diffuses, or sublimes by heat, and the dyes used in conventionally known thermal transfer sheets can be effectively used in the present invention. Properties and solubility in binder are selected. Preferred dyes include, for example, diarylmethane-based, triarylmethane-based, thiazole-based, methine-based such as merocyanine, indoaniline, acetophenone azomethine, pyrazoloazomethine, imidazole azomethine, imidazoazomethine, azomethine typified by pyridone azomethine, Xanthene-based, oxazine-based, dicyanostyrene, cyanomethylene-based represented by tricyanostyrene, thiazine-based, azine-based, acridine-based, benzeneazo-based, pyridone-azo, thiophenazo, isothiazole-azo, pyrrole-azo, pyral-azo, imidazole-azo, thiadiazole-azo , Azo series such as triazoleazo, diazozo, spiropyran series, indinospiropyran series, fluorane series, rhodamine lactam series, naphthoquinone series, anthraquinone series Include those with quinophthalone. Specifically, the following dyes are used, for example. CI (Color Index) Disperse Yellow 51,3,54,79,6
0,23,7,141 CI Disperse Blue 24,56,14,301,334,165,19,72,8
7,287,154,26,354, CI Disperse Red 135,146,59,1,73,60,167 CI Disperse Orange 149 CI Disperse Violet 4,13,26,36,56,31 CI Disperse Yellow 56,14,16,29,201 CI Solvent Blue 70,35,63,36,50,49,111,105,97,1
1 CI Solvent Red 135,81,18,25,19,23,24,143,146,
182 CI Solvent Violet 13 CI Solvent Black 3 CI Solvent Green 3 For example, as a cyan dye, Kayaset Blue 714 (Nippon Kayaku, Solvent Blue 63) Foron Brilliant Blue-SR (Sand, Disperse Blue 354) ,
Waxolin AP-FW (ICI, Solvent Blue 3
6), as a magenta dye, MS-REDG (manufactured by Mitsui Toatsu, Disperse Red 60), Macrolex Violet R (manufactured by Bayer, Disperse Violet 26),
Foron Brilliant Yellow S- as a yellow dye
Dyes such as 6GL (made by Sand, Disperse Yellow 231) and Macrolex Yellow 6G (made by Bayer, Disperse Yellow 201) can be used.

As the resin binder for supporting the dye as described above, known ones can be used, and examples thereof include cellulosic resins such as ethyl cellulose, ethyl hydroxycellulose, hydroxypropyl cellulose, methyl cellulose and cellulose acetate, polyvinyl alcohol, Examples include vinyl resins such as polyvinyl acetate, polyvinyl butyral, polyvinyl acetal, and polyvinylpyrrolidone, acrylic resins such as poly (meth) acrylate and poly (meth) acrylamide, polyurethane resins, polyamide resins, polyester resins, etc. Alternatively, they can be optionally used by mixing. Among these, polyvinyl butyral and polyvinyl acetal are preferable from the viewpoints of dye migration and storability as a thermal transfer sheet.

In the present invention, the following releasable graft copolymer can be used as a releasing agent or a resin binder instead of the above binder resin. These releasable graft copolymers are obtained by graft-polymerizing at least one releasable segment selected from polysiloxane segment, fluorohydrocarbon segment, fluorocarbon segment or long-chain alkyl segment on the polymer main chain. is there.

Of these, particularly preferred is a graft copolymer obtained by grafting a polysiloxane segment on the main chain composed of a polyvinyl acetal resin. To produce the above graft copolymer, for example,
It is obtained by reacting a polysiloxane having a functional group with diisocyanate to produce a silicone chain for grafting, and grafting this grafting silicone chain onto polyvinyl acetal. Specifically, for example, in a solvent in which hexamethylene diisocyanate and dimethylpolysiloxane having a hydroxyl group at one end are mixed with methyl ethyl ketone and methyl isobutyl ketone in a ratio of 1: 1, a tin-based catalyst (for example, dibutyltin) is added in an amount of 0.01 ~ 1
A grafting silicone chain is produced at a reaction temperature of about 00 ° C. Next, the silicone graft polyvinyl acetal resin can be produced by reacting the grafting silicone chain and the polyvinyl acetal resin in a solvent in which methyl ethyl ketone and methyl isobutyl ketone are mixed at a ratio of 1: 1.

When such a graft copolymer is added to the dye layer to be used as a mold releasing agent, the content of the mold releasing segment in the mold releasing agent is such that the amount of the mold releasing segment in the graft copolymer is 10. A proportion of ˜80% by weight is preferable, and if the amount of the releasable segment is too small, the releasability becomes insufficient, while if it is too large, the compatibility with the resin binder decreases and problems such as dye migration may occur. It is not preferable because it occurs. When the above releasing agent is added to the dye layer, it can be used alone or as a mixture,
The addition amount is 1 to 100 parts by weight of the resin binder.
40 parts by weight is preferred. If the addition amount is too small, the releasing effect is insufficient, and if the addition amount is too large, the migration of the dye in the dye layer and the film strength are lowered, and the discoloration of the dye in the dye layer and the storability of the thermal transfer sheet are problematic. It is not preferable because it occurs. On the other hand, when the above graft copolymer is used as the resin binder of the dye layer, the content of the releasing segment in the resin binder is such that the amount of the releasing segment in the resin binder is 0.5 to 40% by weight. It is preferable that the ratio is too small, and if the amount of the releasable segment is too small, the releasability of the dye layer becomes insufficient. Conversely, if it is too large, the migration of the dye in the dye layer and the film strength as a resin decrease. In addition, discoloration of the dye in the dye layer and storability of the heat transfer sheet may occur, which is not preferable.

The sublimable dye layer region 2 is preferably dissolved in an appropriate organic solvent or dispersed in an organic solvent or water, by adding various additives as necessary to the dye and the resin binder as described above. Gravure printing the dispersion,
The dye layer can be formed by coating and drying the base sheet by a forming means such as a screen printing method or a reverse roll coating method using a gravure plate. In this case, the dye layer may be provided by one application, but may be provided by two applications. By forming in this way, the dye concentration per unit area can be increased. Further, by forming the outermost layer of the dye layer as a layer containing a releasable resin as described above, heat fusion is prevented even when printed on an image receptor such as a plastic card having a poor releasable component at the time of printing. it can. The thickness of the dye layer formed as described above is 0.2 to 5.0 μm, preferably 0.4 to
A thickness of 2.0 μm is suitable. Monochromatic printing may be used for this printing, but for the purpose of the present invention, multicolor printing of three colors of yellow, magenta, and cyan, and further four colors including black is preferable so that a color image can be formed.

In the present invention, a heat fusible ink layer region 3 may be provided adjacent to the sublimable dye layer region 2. The constitution of the heat-meltable ink layer region 3 includes a base sheet 1
It is preferable to form the release layer 8, the peeling protection layer 9, and the heat-fusible ink layer 10 in order from the side. Examples of the release layer 8 include waxes forming the ink layer 10 described later, silicone wax, silicone resin, fluororesin, acrylic resin, cellulose resin, vinyl chloride / vinyl acetate copolymer, nitrocellulose, urethane resin, polyvinyl. It is formed from a release agent such as alcohol resin. The forming method may be the same as the forming method of the dye layer region 2, and the thickness thereof is 0.
About 1 to 5 μm is sufficient. When a matte printing or matte protective layer is desired after transfer, the surface of the mold release layer 8 can be finished in a matte state by incorporating various particles. The release protection layer 9 provided on the release layer 8 is preferably formed of a resin having excellent transparency, abrasion resistance, chemical resistance, and the like, such as acrylic resin, polyester resin, and polyurethane resin. As for the forming method, a solution of an appropriate resin is prepared in the same manner as in the dye layer area 2, and then a solution of an appropriate resin is prepared in the same manner as in the dye layer area, and the solution is applied as described above or the printing method. so,
It may be formed with a thickness of 0.2 to 10 μm. When these peeling protection layers 9 are formed, a filler such as silica or alumina may be added in order to improve film breakage during thermal transfer. In addition, waxes such as polyethylene wax may be added to the release protective layer in order to improve abrasion resistance and slipperiness. The release layer 8 may be omitted if the release protection layer has sufficient release properties from the base sheet. Further, the same material such as a release layer used for the transferable protective layer region described later may be used.

The heat-fusible ink layer 10 formed on the peeling protection layer 9 is composed of a colorant and a vehicle, and may contain any additive if necessary. The colorant is preferably an organic or inorganic pigment or dye having good characteristics as a recording material, for example, one having a sufficient coloring density and not fading due to light, heat, temperature or the like. . As the colorant, cyan, magenta, yellow and the like can be used, but for the purpose of the present invention, a black colorant capable of printing clear characters and symbols at high density is preferable.

As the vehicle to be used, a mixture containing wax as a main component and other wax and a drying oil, a resin, a mineral oil, a derivative of cellulose and a rubber is used. Examples of the wax include microcrystalline wax, carnauba wax, paraffin wax, and the like.In addition, Fischer-Tropsch wax, various residence molecular weight polyethylene, wooden wax, beeswax, whale wax, ivowa wax, wool wax, shellac wax, candelilla wax, Various waxes such as petrolactam, partially modified wax, fatty acid ester and fatty acid amide can be used. However, in the case of the present invention, as a binder of the black ink layer, from the viewpoint of adhesiveness to a card and foil cutting property,
It is more preferable to use a vinyl chloride / vinyl acetate copolymer resin, or an acrylic resin, or a resin obtained by mixing acrylic resin with at least one of chlorinated rubber, vinyl chloride / vinyl acetate copolymer resin, and cellulosic resin. preferable.

As a method of forming the heat-fusible ink layer 10 on the release protection layer 9 provided on the substrate sheet 1, in addition to hot melt coating, hot lacquer coating, gravure coating, gravure reverse coating, roll coating, etc. It can be applied by a known method. The thickness of the ink layer to be formed should be determined so that the necessary concentration and thermal sensitivity can be balanced, and it is usually preferable to form it in the range of 0.2 to 10 μm.

The transferable protective layer region 4 provided adjacent to the color material layer composed of the sublimable dye layer region 2 and / or the heat-fusible ink layer region 3 is provided with a release layer 5 from the base sheet 1 side. ,
It is preferable to form the ionizing radiation curable resin layer 6 and the adhesive layer 7 in this order. For the release layer 5, in addition to the above-mentioned material capable of forming the release layer, a coating liquid containing a wax, a silicone wax, a silicone resin, a fluororesin, an acrylic resin, polyvinyl alcohol or the like as a main component is used for gravure coating,
Application by a conventionally known method such as gravure reverse coating,
It can be formed by drying, and the thickness of the release layer is 0.
About 1 to 2 μm is sufficient. Further, when a matte protective layer is desired in the printed matter after transfer, various particles are included in the release layer or a base material having a release layer forming surface matt treated is used for protection. The surface of the printed matter on which the layer is transferred can be placed on the mat. The release layer as described above may be omitted if the releasability between the ionizing radiation curable resin layer and the base sheet is good.

The resin contained in the ionizing radiation-curable resin layer 6 in the present invention is a resin obtained by crosslinking and curing a polymer or oligomer having a radical-polymerizable double bond in its structure by irradiation with ionizing radiation. If necessary, a photopolymerization initiator is added and polymerized and crosslinked by an electron beam or an ultraviolet ray. Any conventionally known ionizing radiation curable resin can be used and is not particularly limited. Examples of the radical-polymerizable monomer include acrylic acid esters, methacrylic acid esters, acrylamides, methacrylamides, allyl compounds, vinyl ethers, vinyl esters, vinyl heterocyclic compounds, N
-Vinyl compounds, styrene, acrylic acid, methacrylic acid, crotonic acid, itaconic acid and the like, and examples of polyfunctional monomers include diethylene glycol diacrylate, diethylene glycol dimethacrylate, triethylene glycol diacrylate, triethylene glycol diacrylate. Methacrylate, tetraethylene glycol diacrylate, tetraethylene glycol dimethacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, pentaerythritol tetraacrylate, pentaerythritol tetramethacrylate, dipentaerythritol hexaacrylate, dipentaerythritol hexa Methacrylate, tris (β-acryloyloxyethyl) isocyanurate , Tris (beta-meth acryloyloxyethyl) isocyanurate. Further, when using ultraviolet irradiation, as the sensitizer, benzoethers such as benzoin and benzoin methyl ether, halogenated acetophenones, and those that generate radicals by ultraviolet irradiation such as diacetyl are used for the radical polymerizable monomer. You may add and use about 1 to 20 weight%.

In the ionizing radiation curable resin as described above,
In order to improve flexibility and adhesiveness, a cellulose resin such as ethyl cellulose, a polyester resin, a polyurethane resin, a rosin ester resin, a rubber resin such as a cyclized rubber, an acrylic resin or the like may be mixed if necessary. You may use. Further, although these resins have excellent transparency, they tend to form a relatively tough film, and therefore the film breakage during transfer may not be sufficient. Therefore, when forming the ionizing radiation curable resin layer, it is desirable to add a relatively large amount of highly transparent particles to the curable resin layer. Examples of the particles include fine particles of silica having a particle size of about 0.01 to 50 μm, inorganic particles such as alumina, calcium carbonate, talc, and clay, and organic fillers such as acrylic resin, polyester resin, melamine resin, epoxy resin, and polyethylene resin. Is mentioned. When particles of silica, alumina, etc. are used, in order to improve the compatibility with the ionizing radiation curable resin, those obtained by treating the surface of silica, alumina, etc. with a silane coupling agent or the like may be used. Examples of the silane coupling agent include γ-methacryloxypropyltrimethoxysilane, γmethacryloxypropylmethyldimethoxysilane, γmethacryloxypropyldimethylmethoxysilane, γmethacryloxypropyltriethoxysilane, γmethacryloxypropyldimethylethoxysilane, and γ. Acryloxypropyltrimethoxysilane, γacryloxypropyldimethylmethoxysilane, γacryloxypropyltriethoxysilane, γacryloxypropylmethyldiethoxysilane, γacryloxypropyldimethylethoxysilane,
Vinyl ethoxysilane etc. are mentioned. The amount of the silane coupling agent to be treated is preferably such that the minimum coating area of the silane coupling agent is 10 to 100 with respect to 100 of the specific surface area of silica or alumina.

Such highly transparent particles are preferably contained in a proportion of 5 to 50 parts by weight per 100 parts by weight of the ionizing radiation-curable resin. If the amount is less than the above range, film breakage during transfer will be insufficient. On the other hand, if the amount is too large, the transparency of the protective layer is insufficient, which is not preferable. Furthermore, by adding waxes, lubricants, ultraviolet absorbers, antioxidants and / or optical brighteners as other additives, the lubricity, gloss, light resistance, weather resistance and whiteness of various images to be coated can be improved. Can be improved.

In the present invention, an ink is prepared by adding an appropriate solvent or additive to the ionizing radiation curable resin composed of the above-mentioned components, if necessary, to adjust the viscosity and the like to prepare an ink on a substrate sheet. Is coated, dried and cured by a known means such as gravure coating, gravure reverse coating and roll coating to form an ionizing radiation curable resin layer. The thickness of these cured resin layers is preferably about 1 to 10 μm. Radiation such as ultraviolet rays or electron beams is used to cure the ionizing radiation curable resin layer. Conventional techniques can be used as they are for radiation irradiation, for example, in the case of electron beam curing,
50 to 1000 keV, preferably 10 emitted from various electron beam accelerators such as Cockloft-Walton type, Van de Graaff type, resonance transformer type, insulating core transformer type, linear type, electro curtain type, dynamitron type, and high frequency type.
An electron beam or the like having an energy of 0 to 300 keV is used. In the case of UV curing, ultra high pressure mercury lamp,
Ultraviolet rays emitted from a light source such as a high pressure mercury lamp, a low pressure mercury lamp, a carbon arc, a xenon arc, and a metal halide lamp are used. Curing by ionizing radiation may be performed after forming the curable resin layer or after forming all layers.

In the transferable protective layer region 4 of the present invention,
In order to improve the light resistance of the printed matter, it is desirable to provide the ultraviolet blocking layer 13. The location where the ultraviolet blocking layer is formed is not limited whether it is provided between the release layer 5 and the ionizing radiation curable resin layer 6 or between the ionizing radiation curable resin layer 6 and the adhesive layer 7. It is preferable to provide it. Further, it is also possible to use a resin in which a reactive ultraviolet absorber as described later is reactively bonded to the ionizing radiation curable resin layer. In the case of a child, a resin in which a reactive ultraviolet absorber is reactively bonded can be used alone or in combination. The ultraviolet blocking layer 13 used in the present invention is characterized by containing a resin obtained by reactively bonding a reactive ultraviolet absorber. Specifically, conventionally known organic UV absorbers such as salicylates, benzophenones, benzotriazoles, substituted acrylonitriles, nickel chelates,
For non-reactive UV absorbers such as hindered amines, addition polymerizable double bonds such as vinyl group, acryloyl group, methacryloyl group, or alcoholic hydroxyl group, amino group, carboxyl group, epoxy group, isocyanate group, etc. It is possible to use those having introduced thereinto, for example, a reactive ultraviolet absorber represented by the following structural formula can be used.

[0027]

[Chemical 1]

[Chemical 2]

Various methods can be used as a method for reacting and fixing the above-mentioned reactive ultraviolet absorber to a resin.
For example, by radically polymerizing a conventionally known monomer, oligomer, or resin component of a reactive polymer and a reactive ultraviolet absorber having an addition polymerizable double bond as described above,
A copolymer can be obtained. Further, the reactive ultraviolet absorber is a hydroxyl group, an amino group, a carboxyl group, an epoxy group,
In the case of having an isocyanate group or the like, the above-mentioned reactive group and a thermoplastic resin having a reactive group are used, and if necessary, a catalyst is used to react and fix the reactive ultraviolet absorber to the thermoplastic resin by heat or the like. can do. Examples of the monomer component that is copolymerized with the reactive ultraviolet absorber include the following.

Methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, tertiary butyl (meth) acrylate, isodecyl (meth) acrylate, lauryl (meth) ) Acrylate, lauryl tridecyl (meth) acrylate,
Tridecyl (meth) acrylate, ceryl stearyl (meth) acrylate, stearyl (meth) acrylate, ethylhexyl (meth) acrylate, octyl (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, methacrylic acid, hydroxyethyl (meth ) Acrylate, hydroxypropyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, tert-butylaminoethyl (meth) acrylate, glycidyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, ethylenedi (Meth) acrylate, diethylene glycol (meth) acrylate, triethylene glycol di (meth) acrylate, tetrae Lenglycol di (meth) acrylate, decaethylene glycol (meth) acrylate, pentadecaethylene (meth) acrylate, pentacontaethylene ethylene glycol (meth) acrylate, butylene (meth) acrylate, allyl (meth) acrylate, trimethylolpropane tri (Meth) acrylate, hexanediol di (meth) acrylate, tripropylene glycol di (meth) acrylate, pentaerythritol tetra (meth) acrylate, pentaerythritol hexa (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 1,6 -Hexanediol di (meth) acrylate, neopentyl glycol penta (meth) acrylate, phosphazene hexa (meth) acrylate, etc. are used. It can be.

The above substances may be used not only as a monomer but also as an oligomer, and further, a polyester acrylate-based compound comprising a polymer of the above substance or a derivative thereof,
An acrylic reactive polymer such as an epoxy acrylate type can also be used. These monomers, oligomers, and acrylic reactive polymers may be used alone or in combination.

A thermoplastic copolymer resin in which the reactive ultraviolet absorber is reactively fixed by copolymerizing the monomer, oligomer or acrylic reactive polymer of the thermoplastic resin and the reactive ultraviolet absorber as described above. However, 10 to 90% by weight, preferably 30% by weight is contained in this copolymer resin.
It is desirable to contain ˜70 wt% reactive UV absorber. If the content is less than this range, it is difficult to obtain satisfactory weather resistance, and if it is more than this range, problems such as stickiness during coating and image bleeding during transfer to a dye image occur. The molecular weight of this copolymer resin is 5
000 to 250,000 is preferable, and further 9000
About 30000 is good. If the molecular weight is less than 5,000, the film strength will be poor, and if it exceeds 250,000, the film breakage will be poor when the protective layer is transferred by a thermal head or the like. An example of the structural formula of the thermoplastic resin obtained by copolymerizing the reactive ultraviolet absorber is shown below, but the copolymer resin of the present invention should not be limited thereto.
Further, with a thermoplastic resin obtained by copolymerizing the reactive ultraviolet absorber, a conventionally known organic ultraviolet absorber such as benzophenone-based, benzotriazole-based, salicylate-based, hindered amine-based, titanium oxide, or oxidation. An inorganic ultraviolet absorber such as zinc or cerium oxide may be used in combination.

When the ultraviolet absorbing layer as described above is formed on the ionizing radiation curable resin layer, a primer layer can be formed when the adhesion is poor. Examples of the resin forming the primer layer include acrylic resins such as methyl methacrylate and ethyl acrylate.
It is preferable that the thickness is in the range of 0.1 to 5 μm. )

Next, the adhesive layer 7 that makes the transfer of the protective layer more effective will be described. The adhesive layer is provided on the outermost layer in the transferable protective layer area, and is heated, for example, with acrylic resin, vinyl chloride resin, vinyl acetate resin, vinyl chloride / vinyl acetate copolymer resin, polyester resin, polyamide resin, etc. By using a solution of a resin having good adhesiveness, the thickness can be provided in the range of 0.1 to 5 μm by the same method as described above. The ionizing radiation curable resin layer 6 and the adhesive layer 7 are
A primer layer can be provided when the adhesiveness of is poor. As the primer layer to be used, an acrylic resin such as methyl methacrylate or ethyl methacrylate can be used, and methyl methacrylate is preferable from the viewpoints of coating suitability and plasticizer resistance to images. When an acrylic monomer is used as a component of the ionizing radiation curable resin layer, it is preferable to use an acrylic resin as the primer layer. The thickness of the primer layer is 0.1.
It is preferably about 5 μm. By providing such a primer layer, the adhesive force between the ionizing radiation curable resin layer and the adhesive layer is improved, and by mixing both components, the release layer and the ionizing radiation protective layer are firmly adhered, and the base material Problems such as the protective layer not peeling off from the film can be prevented.

The thermal transfer sheet of the present invention is obtained by forming the sublimable dye layer region 2, the heat-fusible ink layer region 3, and the transferable protective layer region 4 as described above on the substrate sheet 1 in the face-sequential manner. However, the order of formation is not particularly limited. For example, although not shown, a dye layer of yellow, magenta, cyan, and black may be provided as the sublimable dye layer region 2, and then a black heat-meltable ink layer and a transferable protective layer may be formed in this order. In addition, a yellow, magenta, and cyan dye layer is provided as the sublimable dye layer region 2,
Next, the black heat-meltable ink layer and the transferable protective layer may be formed in this order, or the sublimable dye layer region 2 may be omitted, and the black heat-meltable ink layer and the transferable protective layer may be further formed. As an alternative, before forming the sublimable dye layer region 2, the transferable receiving layer region may be formed by using a receiving layer forming resin described later. By providing the transferable receptive layer area in this way, it is possible to form the receptive layer prior to recording even on a paper with poor dyeability and a plastic card with poor dyeability such as ABS resin, which enables transfer. It is possible to expand the target.

As the transfer material for forming an image using the thermal transfer sheet of the present invention, plastic films such as polyester resin, vinyl chloride, vinyl chloride-vinyl acetate copolymer resin and polycarbonate resin can be used, particularly vinyl chloride. For vinyl chloride-vinyl acetate copolymer resins and the like, the resin itself has a dyeing property, so that the receiving layer can be omitted. When these plastic cards do not show sufficient dyeability with respect to the sublimable dye, a plasticizer or the like may be added to the resin to adjust the dyeability. Also,
As another transfer target, a plastic film or paper provided with a dye receiving layer, woven fabric or non-woven fabric made of synthetic fibers such as polyester fiber, polyamide resin, polypropylene fiber and vinylon fiber can be used. When a dye receiving layer is provided, any known sublimation type transfer recording receiving layer resin can be used, and particularly vinyl resins, polycarbonate resins, polyester resins and polyvinyl acetal resins are sublimable. It is preferable in that it receives a dye and maintains the formed image.

When the transfer sheet of the present invention is used for a card, it may be embossed, a writable layer for signature, an IC memory, a magnetic layer, and other printing may be applied in advance, or a protective layer. Embossing, signature, IC after transfer
It is also possible to provide a memory, a magnetic layer and the like.

The sublimable dye layer region of the thermal transfer sheet of the present invention is superposed on the above-mentioned image receptor, and a desired color image is formed on the basis of image information by a heating means such as a thermal head or a laser. Next, similarly, heat-meltable ink layers are overlaid to print desired characters, symbols and the like. Next, the transferable protective layer region is transferred onto the formed image, but a thermal head may be used as well, or a hot stamper, a heat roll, a line heater, an iron or the like may be used. The protective layer may be transferred to the entire surface of the formed image or may be transferred to any shape. For example, the protective layer may be transferred only on the image formed by the sublimable dye, or may be transferred to the area covering the image formed by the sublimable dye and the characters, symbols and the like made of the hot-melt ink. For the transfer of the protective layer, the thermal head used when forming the image with the sublimable dye can be used as it is, or other heating means such as a heat roll may be used only when transferring the protective layer. .

[0038]

EXAMPLES Next, the present invention will be described more specifically with reference to examples. In the text, "part" or "%" is based on weight unless otherwise specified. Example 1 An ink for a heat resistant slipping layer having the following composition was dried on one surface of a polyethylene terephthalate long film (Lumirror: made by Toray, width 10 cm) having a thickness of 6 μm and subjected to easy adhesion treatment, when dried: 1.0 g / m ^2. Was coated and dried using a gravure coater to provide a heat resistant slipping layer, and further cured by heating and aging in an oven at 60 ° C. for 5 days. Ink for heat resistant slipping layer Polyvinyl butyral resin (S-REC BX-1 Sekisui Chemical Co., Ltd.) 3.6 parts Polyisocyanate (Bernock D750 manufactured by Dainippon Ink) 8.4 parts Phosphate ester surfactant (Prysurf A208S Daiichi Kogyo) Pharmaceutical) 2.8 parts Talc (Microace P-3 Nippon Talc) 0.6 parts Toluene / methyl ethyl ketone (1/1) 190 parts

Next, a sublimation dye layer composed of the following composition was provided on the surface opposite to the heat resistant slipping layer, with a width of 10 cm and 14 c.
The three colors were set as one set at an interval of m and coated by a gravure coater so as to be 1.0 g / m ² when dried, and dried, and an interval of 28 cm was provided between each set. Yellow ink dye (Fron Brilliant Yellow S-6GL) 5.5 parts Polyvinyl acetoacetal resin (KS-5: Sekisui Chemical Co., Ltd.) 4.5 parts Polyethylene wax 0.1 part Methylelketone / toluene (1/1) 89 Part Magenta ink Magenta dye (MS Red G 1.5
Parts, and 2.0 parts of Macrolex Red Violet R) were used. Cyan ink Instead of yellow dye, cyan dye (Kayaset Blue 71
Same as the yellow ink except that 4) was used.

Next, the release layer ink was used to dry 1.0 g / m ^{2 on the} portion where the dye layer was not formed by a gravure coater.
And a coating layer were dried to form a release layer. Ink for forming release layer Polyurethane resin (Hydrolan AP-40, manufactured by Dainippon Ink) 70 parts Polyvinyl alcohol (Gosenol C-500, manufactured by Nippon Synthetic Chemical Industry) 30 parts Fluorescent whitening agent (manufactured by Uvitex OB Ciba Geigy) 0.5 part Methyl ethyl ketone / toluene (1/1) 300 parts Next to the cyan dye layer is 10 cm wide and 14
Ink for peeling protective layer below (1.0 at dry time)
g / m ² ) and ink for hot-melt ink (1.0 when dry)
g / m ² ) was applied and dried to form a hot melt ink layer region. Ink for peeling protection layer Acrylic resin (BR-83, manufactured by Mitsubishi Rayon) 88 parts Polyethylene wax 11.5 parts Polyester 0.5 parts Optical brightener 0.5 parts Methyl ethyl ketone / toluene (1/1) 300 parts Thermal melting property Ink for ink layer Vinyl chloride / vinyl acetate copolymer resin) 60 parts Carbon black 40 parts Methyl ethyl ketone / toluene (1/1) 200 parts

Next, ink for ionizing radiation curable resin layer (drying 2.0 g / m ² ) and ink for primer layer (drying) were formed adjacent to the heat-meltable ink layer region at intervals of 10 cm and 14 cm in width. 1.0 g / m ² ) was applied using a gravure coater and dried. Ionizing radiation curing resin layer Dipentaerythritol hexaacrylate 10 parts Polymethylmethacrylate 20 parts Silane coupling agent treated silica 3 parts Polyethylene wax 1 part Methylethylketone / toluene (1/1) 70 parts Primer layer forming ink Polymethylmethacrylate 30 parts Methylethylketone / Toluene (1/1) 70 parts Next, on the transferable protective layer region formed as described above, the following adhesive layer ink was used to form a layer having a thickness of 1.0 g / m ² when dried. did. Ink for adhesive layer Vinyl chloride / vinyl acetate copolymer resin (# 1000ALK, manufactured by Denki Kagaku Kogyo) 30 parts Optical brightener (Uvitex OB manufactured by Ciba Geigy) 0.15 parts Methyl ethyl ketone / toluene (1/1) 70 As described above, each area of the sublimable dye layer, the heat-fusible ink layer and the transferable protective layer was applied in a face-sequential manner, dried, and then 5 Mrads of an electron beam accelerated to 175 kV in a nitrogen gas atmosphere from the coating surface side. The resin layer of the transferable protective layer was cured and cross-linked by irradiation.

Example 2 A thermal transfer sheet was prepared in the same manner as in Example 1 except that the following UV blocking layer ink was similarly applied and dried between the primer layer and the adhesive layer in the transferable protective layer region to provide a UV blocking layer. Got Ink for UV blocking layer Copolymer resin (UVA-635L, manufactured by BASF Japan) reactively bonded with a reactive UV absorber 20 parts Toluene / methyl ethyl ketone (1/1) 80 parts Example 3 The following UV blocking layer in Example 2 A thermal transfer sheet was similarly obtained except that the ink for use was used. (Replace the resin with that in Example 2) Ink for ultraviolet blocking layer Copolymer resin (UVA-935LH, manufactured by BASF Japan) reactively bonded with a reactive ultraviolet absorber 20 parts Ethyl acetate 80 parts Example 4 Example 2 In the same manner as above, a thermal transfer sheet was obtained in the same manner except that the following ink for ultraviolet blocking layer was used. Copolymer resin (UVA-635L, manufactured by BASF Japan) in which a reactive ultraviolet absorbent is reaction-bonded 20 parts Benzophenone-based ultraviolet absorbent (Uvinul D-49 manufactured by BASF Japan) 1 part Toluene / methyl ethyl ketone (1/1) 80 parts

Comparative Example 1 In Example 1, a peeling protection layer was not provided in the hot-melt ink layer region, a primer layer was omitted in the transferable protection layer region, and instead of the ionizing radiation curing resin layer, the following protection was performed. It was applied and formed using the layer ink. A heat transfer sheet was obtained in the same manner as in Example 1 with respect to the heat resistant slipping layer, the sublimable dye layer, the release layer, the heat fusible ink layer, the adhesive layer and the like. However, in Comparative Example 1, the curing treatment by irradiation with ionizing radiation was not performed. Ink for protective layer Acrylic resin (BR-83 manufactured by Mitsubishi Rayon) 30 parts Polyethylene wax 1.5 parts Toluene / methyl ethyl ketone (1/1) 70 parts Comparative Example 2 In Comparative Example 1, the adhesive layer of the protective layer ink was as follows. By the same method as Comparative Example 1 except that the composition was applied and formed,
A thermal transfer sheet was obtained. Ink for forming adhesive layer Vinyl chloride / vinyl acetate copolymer (# 1000ALK manufactured by Denki Kagaku Kogyo Co., Ltd.) 20 parts Benzotriazole-based ultraviolet absorber (Tinuvin 328 manufactured by Ciba Geigy) 1 part Toluene / methyl ethyl ketone (1/1) 80 parts Comparative Example 3 A thermal transfer sheet was obtained in the same manner as in Comparative Example 1 except that the adhesive layer ink was applied and formed in the following composition in Comparative Example 2. Ink for forming adhesive layer Vinyl chloride / vinyl acetate copolymer (# 1000ALK Denki Kagaku Kogyo Co., Ltd.) 20 parts Benzotriazole-based UV absorber (Tinuvin 328 manufactured by Ciba Geigy) Toluene / methyl ethyl ketone (1/1) 80 parts

Polyvinyl chloride (polymerization degree 800) compound 10 containing about 10% of an additive such as a stabilizer as a material to be transferred for printing using the above thermal transfer sheet.
0 part, white pigment (titanium oxide) 10 parts, plasticizer (DO
P) A card base material consisting of 0.5 parts was prepared. Next, on the surface of this card base material, the sublimable dye layer regions of the thermal transfer sheets of each of the examples and comparative examples were overlaid, and thermal energy was applied by a thermal head connected to an electric signal obtained by color-separating a facial photograph. Then, a full-color facial photograph was formed. Furthermore, transfer and form letters and symbols using the heat-meltable ink layer area,
The protective layer was transferred so as to cover the face photograph portion, letters and symbol portion of the card. Then, the following tests were performed on the finished card. (Plasticizer resistance test) A poppy rubber was placed on the surface of the above card, and a load of 30 g / cm ² was applied from above to 60 ° C.
It was stored below for 10 hours. ○: No image dropout was observed ×: Image dropout was seen (light resistance test) The above card was measured with a xenon fade meter (Atlas Co., Ci35A) at a black panel temperature of 45 ° C and 200 kJ / After storing under the condition of m ² , the residual ratio of the formed image near the reflection density of 1.0 was measured. ◎ ・ ・ ・ Residual rate 90% or more ○ ・ ・ ・ Residual rate 80% or more and less than 90% △ ・ ・ ・ Residual rate 60% or more and less than 80% × ・ ・ ・ Residual rate less than 60% (bleeding test) 60 cards above After storing at ℃ for 1 week, the spread of dots was observed with a magnifying glass. ◯: No dot spread was observed ×: Dot spread was observed Table 1 shows the results of each test.

[0045]

[Table 1]

[0046]

[Effect] According to the above-mentioned constitution, one thermal transfer sheet can provide an excellent gradation image by the sublimation dye and / or
A monotone image can be easily formed with the hot-melt ink. Further, it is a feature of the present invention on the obtained image,
By transferring the transferable protective layer made of an ionizing radiation curable resin, it becomes possible to obtain a transferred image having excellent plasticizer resistance, chemical resistance and abrasion resistance. Further, when a peeling protection layer is provided in the heat-fusible ink layer region, it is possible to form a monotone image having excellent durability such as abrasion resistance. Further, in the transferable protective layer region, by providing a layer containing a resin in which a reactive ultraviolet absorber is reactively bonded between the ionizing radiation curable resin layer and the adhesive layer, an image excellent in light resistance can be obtained. Can be formed.

[0047]

[Brief description of drawings]

FIG. 1 is a diagram schematically illustrating a cross section of a thermal transfer sheet of the present invention.

FIG. 2 is a diagram schematically illustrating a cross section of a thermal transfer sheet of the present invention.

FIG. 3 is a diagram schematically illustrating a cross section of a thermal transfer sheet of the present invention.

FIG. 4 is a diagram schematically illustrating a plane of a thermal transfer sheet of the present invention.

FIG. 5 is a diagram schematically illustrating a stepped surface of the thermal transfer sheet of the present invention.

[Explanation of symbols]

 1: Substrate sheet 2: Sublimation dye layer region 2Y: Yellow dye layer 2M: Magenta dye layer 2C: Cyan dye layer 3: Hot melt ink layer region 4: Transferable protective layer region 5, 8: Release layer 6 : Ionizing radiation curable resin layer 7: Adhesive layer 9: Peeling protection layer 10: Hot melt ink layer 11: Heat resistant slip layer 12: Primer layer 13: UV blocking layer

Claims (5)

[Claims] 1. A substrate sheet having at least one surface on one surface thereof.
In a thermal transfer sheet in which a color material layer region of color and a transferable protective layer region are provided in a surface-sequential manner, the transferable protective layer region is provided so that an ionizing radiation curable resin layer can be peeled off. A thermal transfer sheet. 2. The thermal transfer sheet according to claim 1, wherein the color material layer comprises a sublimable dye layer of yellow, magenta and cyan. 3. The thermal transfer sheet according to claim 2, further comprising a black heat-fusible ink layer. 4. The thermal transfer according to claim 1, wherein the transferable protective layer region is formed by laminating a release layer, an ionizing radiation curable resin layer, and an adhesive layer in this order from the base material side. Sheet. 5. A layer containing a resin in which a reactive ultraviolet absorber is reactively bonded is provided between the ionizing radiation curable resin layer and the adhesive layer in the transferable protective layer region. 4. The thermal transfer sheet according to 4.