JP2005313434A - Thermal transfer image forming method and image formed product - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermal transfer image forming method and an image formed product, which are excellent in image preservability, particularly, light fastness. <P>SOLUTION: In a thermal transfer image receiving sheet, an image receiving layer containing at least a plasticizer and a binder resin is provided on a substrate. In the thermal transfer image receiving sheet and the thermal transfer image forming method for forming an image by using the thermal transfer sheet, an SP value Sh of the plasticizer, an SP value Sb of the binder resin, an average SP value Sa of the plasticizer and the binder resin, and an SP value Sd of a transfer dye for use in the thermal transfer sheet satisfy expression (1) expressed by ¾Sa-Sd¾≤3, and expression (2) expressed by ¾Sh-Sb¾≤8. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a thermal transfer image forming method and an image formed product having excellent image storage stability, particularly light resistance.

  Conventionally, as a color or monochrome image forming technology, an ink sheet containing a thermal diffusible dye having a property of diffusing and transferring by heating is opposed to an image receiving layer of an image receiving sheet, and a thermal printing unit such as a thermal head or a laser An image forming method is known in which an image is formed by transferring a heat diffusible dye to an image receiving layer in an image-like manner. Such a thermal transfer system is well-established as a method that enables image formation with digital data, does not use a processing solution such as a developer, and can form a high image quality comparable to a silver salt photograph.

  However, with respect to the storage stability and durability of the formed image, the quality is not yet reached as compared with silver salt photography. In recent years, as the printing speed of thermal transfer printers has increased, it has become impossible to obtain a sufficient printing density with conventional thermal transfer recording materials.

  There is a method of adding a plasticizer to the image receiving layer as means for improving the weather resistance, light resistance, and thermal stability of the image in order to increase the image sensitivity and the storage stability of the formed image.

  For example, Japanese Patent Publication No. 60-19138 proposes adding a phthalate ester plasticizer to an image receiving layer made of a polycarbonate resin. JP-A-2-80291 proposes to add an aryl ester, aralkyl ester or the like of phthalic acid to the image-receiving layer, and JP-A-4-296595 discloses phthalic acid as a plasticizer for cellulose ester. It has been proposed to add esters and phosphate esters. The phthalate esters and phosphate esters disclosed in these publications are preferably used as means for improving sensitivity. Furthermore, Japanese Patent Application Laid-Open No. 2000-218947 describes that when a phosphoric acid ester compound, a phthalic acid ester compound and an aliphatic dibasic acid ester compound are used in combination, bleeding out of the plasticizer with time is less likely to occur. Yes. Japanese Patent Application Laid-Open No. 2001-030639 has a crosslinked polymer network containing a polymer binder and an aliphatic ester plasticizer to improve recording sensitivity by containing a phenoxy resin and one or more kinds of plasticizers. A dye image-receiving layer is described in JP-A No. 2001-225561, and JP-A No. 2002-264542 containing a citrate ester compound as a plasticizer for the image-receiving layer.

  However, it has been known that the addition of a plasticizer to the image receiving layer as described above improves the sensitivity and storage stability, but the storage stability, particularly the light resistance of the image, has not yet reached a satisfactory level. Furthermore, stable improvements could not be obtained, such as the effect disappearing when the type of plasticizer or the type of pigment changed.

In addition, for the purpose of improving the stability of the obtained image, particularly fixing property and light resistance, a heat-sensitive transfer material using a chelatable heat-diffusible dye (hereinafter also referred to as post-chelate dye) and an image forming method thereof ( For example, Patent Documents 1 to 3 are disclosed, but the light resistance is still inferior to silver salt photography.
JP 59-78893 A JP 59-109349 A Japanese Unexamined Patent Publication No. 60-2398

  The present invention has been made in view of the above problems, and an object thereof is to provide a thermal transfer image forming method and an image formed product excellent in image storage stability, particularly light resistance.

  The above object of the present invention is achieved by the following configurations.

(Claim 1)
A thermal transfer image-receiving sheet having an image-receiving layer containing at least a plasticizer and a binder resin on a substrate, wherein the SP value of the plasticizer is Sh, the SP value of the binder resin is Sb, and the plasticizer and the binder resin When the average SP value of Sa is Sa and the SP value of the transfer dye used for the thermal transfer sheet is Sd, a thermal transfer image receiving sheet and a thermal transfer sheet satisfying the following formulas (1) and (2) are used, Sh, Sb, Sa, Sd A thermal transfer image forming method, comprising:

Formula (1) | Sa-Sd | ≦ 3
Formula (2) | Sh-Sb | ≦ 8
(Claim 2)
The thermal transfer image forming method according to claim 1, wherein SP values of all transfer dyes used in the thermal transfer sheet satisfy | Sa−Sd | ≦ 3.

(Claim 3)
The thermal transfer image forming method according to claim 2, wherein SP values of all transfer dyes used in the thermal transfer sheet satisfy | Sa−Sd | ≦ 2.

(Claim 4)
The thermal transfer image forming method according to claim 1, wherein the plasticizer used for the thermal transfer sheet is a compound having an ester bond.

(Claim 5)
The thermal transfer image forming method according to any one of claims 1 to 3, wherein the plasticizer used in the thermal transfer sheet is a phosphate ester.

(Claim 6)
The thermal transfer image forming method according to claim 1, wherein the image receiving layer of the thermal transfer image receiving sheet contains a metal ion-containing compound capable of forming a chelate compound with a transfer dye.

(Claim 7)
An image formed product obtained by the thermal transfer image forming method according to claim 1.

  INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a thermal transfer image forming method and an image formed product excellent in image storability, particularly light resistance.

  As a result of earnest research, the present inventor is a thermal transfer image-receiving sheet having an image-receiving layer containing at least a plasticizer and a binder resin on a substrate, wherein the SP value of the plasticizer is Sh and the SP value of the binder resin is When Sb is the average SP value of the plasticizer and the binder resin and Sa is the SP value of the transfer dye used in the thermal transfer sheet, Sh, Sb, Sa, and Sd are the above formulas (1) and (2). It has been found that by forming an image using a thermal transfer image receiving sheet and a thermal transfer sheet that satisfy the requirements, an image formed product having excellent image storage stability, particularly light resistance, can be obtained.

  Although the mechanism of the improvement is not well understood, it is considered that the polymer binder and the dye are not compatible with each other in the image receiving layer, and the dyes are gathered together. At this time, since the binder is plasticized by the presence of the plasticizer, the diffusion of the dye is good and the dye diffuses from the binder surface to a deeper region and is not easily affected by air, so the light resistance is improved to some extent ( Conventional). On the other hand, when the SP values of the plasticizer, binder, and dye satisfy the relationship of the present invention, the compatibility of the dye and binder is improved, and the aggregated dye appears to be in a dispersed state. When the dye is agglomerated, light is efficiently absorbed or electrons are transferred between the dyes, and decomposition of the dye by light has progressed. In the present invention, the aggregation of the dye was removed. Therefore, it is thought that these interactions are eliminated and the light resistance is greatly improved. When the difference in SP value between the image-receiving layer binder and the plasticizer exceeds 8, the effect cannot be obtained because the compatibility between the binder and the plasticizer is poor.

  The present invention will be described in detail below.

In the present invention, the SP value of the transfer dye, plasticizer, and binder resin needs to fall within a specific range. As a method for obtaining the SP value, for example, P.I. A. Small J.M. Appl. Chem. Vol. 3, p71 (1953), an atomic group contribution method using the cohesive energy density and molar volume of each functional group, and the Okitsu method improved based on this method (Journal of the Adhesion Society of Japan Vol. 29). , P204-p211 (1993)). Recently, it can be calculated relatively easily with commercially available software. In the present invention, the SP value is calculated in a unit system of (J / mol) ^0.5 by Fujitsu software CAChe. The average SP value of the binder resin and the plasticizer is a value obtained by multiplying each SP value by the respective mass ratio and adding them.

  As the plasticizer used in the present invention, those having a boiling point of 180 ° C. or higher at normal pressure are preferable. Glutaric acid, adipic acid, sebacic acid, succinic acid, maleic acid, fumaric acid, mazeline acid, phthalic acid, isophthalic acid Or dialkyl esters of dicarboxylic acids such as terephthalic acid, triaryl esters of phosphoric acid, trialkyl esters of glycerin, paraffin, fluorinated paraffin, silicone oil, etc. are readily available, chemically stable and easy to handle. It can be used conveniently in terms of the above. Specifically, dimethyl glutarate, diethyl glutarate, diamyl adipate, di (n) octyl adipate, di (n) octyl sebacate, dibutyl sebacate, dimethyl succinate, diethyl succinate, dimethyl maleate, maleate Diethyl fate, diethyl fumarate, dimethyl phthalate, diethyl phthalate, dibutyl phthalate, di-2-ethylhexyl phthalate, di (n) octyl phthalate, diethyl isophthalate, dibutyl isophthalate, diethyl terephthalate, tricresyl phosphate, Examples thereof include, but are not limited to, triphenyl phosphate, trioctyl phosphate, glyceryl tributyrate, glyceryl tripropionate, paraffin, fluorinated paraffin, and silicone oil.

  Among these, esters are preferable, and phosphate esters are more preferable.

  The effect of the present invention can be obtained by calculating the SP value from these plasticizers in accordance with the SP value of the binder resin and the pigment and appropriately selecting the type and amount of the plasticizer. 5-40 mass% is preferable with respect to an image receiving layer binder, and, as for a plasticizer, 10-30 mass% is more preferable. If it is less than 5% by mass, the effect is small or cannot be obtained, and if it is 40% by mass or more, other adverse effects such as releasability and bleeding of plasticizer become large and cannot be used.

<Thermal transfer image-receiving sheet>
[Base material sheet]
The substrate sheet used in the thermal transfer image-receiving sheet has a role of holding the image-receiving layer, and since heat is applied during thermal transfer, it preferably has a mechanical strength that does not hinder handling even in an overheated state.

  There are no particular limitations on the material of such a base material. For example, condenser paper, glassine paper, sulfuric acid paper, high-size paper, synthetic paper (polyolefin-based, polystyrene-based), high-quality paper, art paper, coated paper , Cast coated paper, wallpaper, backing paper, synthetic resin or emulsion impregnated paper, synthetic rubber latex impregnated paper, synthetic resin internal paper, paperboard, cellulose fiber paper, or polyester, polyacrylate, polycarbonate, polyurethane, polyimide, polyether Imide, cellulose derivative, polyethylene, ethylene-vinyl acetate copolymer, polypropylene, polystyrene, acrylic, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyvinyl butyral, nylon, polyether ether ketone, polysulfone, Examples include polyethersulfone, tetrafluoroethylene, perfluoroalkyl vinyl ether, polyvinyl fluoride, tetrafluoroethylene / ethylene, tetrafluoroethylene / hexafluoropropylene, polychlorotrifluoroethylene, and polyvinylidene fluoride. A white opaque film formed by adding a white pigment or a filler to these synthetic resins or a foamed foam sheet can be used, and is not particularly limited.

  Moreover, the laminated body by the arbitrary combinations of the said base material can also be used. As an example of a typical laminated body, the synthetic paper of a cellulose fiber paper and a synthetic paper or a cellulose synthetic paper and a plastic film is mentioned. The thickness of these substrate sheets may be arbitrary and is usually about 10 to 300 μm.

  In order to obtain higher printing sensitivity and high image quality without density unevenness or white spots, it is preferable to have a layer having fine voids. As the layer having fine voids, a plastic film or synthetic paper having fine voids inside can be used. Moreover, the layer which has a fine space | gap by various coating systems can be formed on various base material sheets. As a plastic film or synthetic paper having fine voids, polyolefin, especially polypropylene, is mainly blended with an inorganic pigment and / or a polymer incompatible with polypropylene, and these are used as void (void) formation initiators. A plastic film or synthetic paper obtained by stretching and forming a mixture of the above is preferable. In the case of those mainly composed of polyester or the like, the cushioning property and heat insulation are inferior to those mainly composed of polypropylene due to their viscoelastic or thermal properties, so that the printing sensitivity is inferior and the density unevenness is inferior. Etc. are also likely to occur.

Considering these points, the elastic modulus at 20 ° C. of the plastic film and the synthetic paper is preferably 5 × 10 ⁸ to 1 × 10 ¹⁰ Pa. In addition, since these plastic films and synthetic paper are usually formed by biaxial stretching, they shrink by heating. When these are left at 110 ° C. for 60 seconds, the shrinkage is 0.5 to 2.5%. The plastic film or synthetic paper described above may be a single layer of a layer containing fine voids, or may have a plurality of layer configurations. In the case of a plurality of layer structures, all the layers constituting the structure may contain fine voids, or a layer having no fine voids may be contained. A white pigment may be mixed in the plastic film or synthetic paper as a concealing agent as necessary. In order to increase whiteness, an additive such as a fluorescent brightening agent may be included. The layer having fine voids preferably has a thickness of 30 to 80 μm.

  As a layer having fine voids, a layer having fine voids can be formed on a substrate by a coating method. As the plastic resin to be used, known resins such as polyester, urethane resin, polycarbonate, acrylic resin, polyvinyl chloride, and polyvinyl acetate can be used singly or in combination.

Further, if necessary, a resin such as polyvinyl alcohol, polyvinylidene chloride, polyethylene, polypropylene, modified polyolefin, polyethylene terephthalate, polycarbonate, or the like is provided on the surface of the substrate opposite to the side on which the image receiving layer is provided for the purpose of preventing curling. And a layer of synthetic paper. As a bonding method, for example, known lamination methods such as dry lamination, non-solvent (hot melt) lamination, EC lamination method and the like can be used, but preferred methods are dry lamination and non-solvent lamination. Examples of the adhesive suitable for the non-solvent lamination method include Takenate 720L manufactured by Takeda Pharmaceutical Co., Ltd., and examples of the adhesive suitable for dry lamination include Takelac manufactured by Takeda Pharmaceutical Co., Ltd. Examples include A969 / Takenate A-5 (3/1), Polysol PSA SE-1400, Vinylol PSA AV-6200 series, manufactured by Showa High Polymer Co., Ltd., and the like. The amount of these adhesives, from about 1-8 g / m ² on a solids, and preferably from 2 to 6 g / m ^2.

  When laminating a plastic film and synthetic paper as described above, or between them, or various papers and a plastic film or synthetic paper, they can be bonded together with an adhesive layer.

  For the purpose of increasing the adhesive strength between the base sheet and the image receiving layer, various primer treatments and corona discharge treatments are preferably performed on the surface of the base sheet.

(Image receiving layer)
The image receiving layer provided on the thermal transfer image receiving sheet is for receiving the sublimation dye moving from the thermal transfer sheet and maintaining the formed image.

<Binder resin>
Binder resins for forming the image receiving layer include polyolefin resins such as polypropylene, halogenated resins such as polyvinyl chloride and polyvinylidene chloride, vinyl resins such as polyvinyl acetate and polyacrylate, polyethylene terephthalate, and polybutylene. Polyester resins such as terephthalate, polystyrene resins, polyamide resins, phenoxy resins, copolymers of olefins such as ethylene and propylene with other vinyl monomers, simple substances such as polyurethane, polycarbonate, acrylic resins, ionomers, cellulose derivatives, Alternatively, a mixture can be used. In addition, SP value of a polymer calculates SP value of each monomer, The numerical value which added together the molar ratio is made into SP value of a polymer. In the case of using the resin together, the SP value of each resin is calculated, and the value obtained by multiplying the mass ratio and adding them is defined as the SP value of the binder resin.

<Release agent>
In the image receiving layer according to the present invention, it is preferable to add a release agent for the purpose of preventing thermal fusion with the dye layer. As the mold release agent, a phosphoric ester plasticizer, a fluorine compound, silicone oil (including reaction curable silicone) and the like can be used, and among these, silicone oil is preferable. As the silicone oil, various modified silicones including dimethyl silicone can be used. Specifically, amino-modified silicones, epoxy-modified silicones, alcohol-modified silicones, vinyl-modified silicones, urethane-modified silicones, and the like can be blended or polymerized using various reactions. The release agent may be used alone or in combination of two or more. Further, the addition amount of the release agent is preferably 0.5 to 30 parts by mass with respect to 100 parts by mass of the binder resin for forming the image receiving layer. When the range of the addition amount is not satisfied, problems such as fusion between the thermal transfer sheet and the image receiving layer of the thermal transfer image receiving sheet or a decrease in printing sensitivity may occur. In addition, you may provide these mold release agents as a mold release layer separately on an image receiving layer, without adding to an image receiving layer.

<Metal ion-containing compound>
The image receiving layer according to the present invention preferably contains a metal ion-containing compound (hereinafter also referred to as a metal source) that can form a chelate compound with a transfer dye.

Examples of the metal source include inorganic or organic salts and metal complexes of metal ions, and among them, salts and complexes of organic acids are preferable. Examples of the metal include monovalent and polyvalent metals belonging to Groups 1 to 10 of the periodic table. Among them, Al, Co, Cr, Cu, Fe, Mg, Mn, Mo, Ni, Sn, Ti, and Zn Of these, Ni, Cu, Cr, Co and Zn are particularly preferable. Specific examples of the metal source include Ni ²⁺ , Cu ²⁺ , Cr ²⁺ , Co ²⁺ and Zn ²⁺ and aliphatic salts such as acetic acid and stearic acid, or aromatic carboxylic acids such as benzoic acid and salicylic acid. Examples include acid salts.

  In the present invention, the metal source may be a compound exemplified in US Pat. No. 4,987,049 or a compound No. exemplified in JP-A-9-39423. 1-99 etc. can be mentioned. Particularly preferred are compounds represented by the following general formula (I) described in JP-A-10-241410.

Formula (I)
M ²⁺ (X ₁ ^-) ₂
In the general formula (I), M ²⁺ represents a divalent transition metal ion, and among these, nickel and zinc are preferred from the color of the metal ion supply compound itself and the color tone of the chelated dye. X ₁ ⁻ represents a coordination compound represented by the following general formula (II) capable of forming a complex with a divalent metal ion.

(In the formula, Z represents an alkyl group, an aryl group, an alkoxy group, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, a carbamoyl group, a halogen atom or a hydrogen atom. R and R ′ each represents an alkyl group or an aryl group. Each may be the same or different, and R and Z or R ′ and Z may combine to form a ring, but when Z is a hydrogen atom, R and R ′ are both methyl groups. No.)
In the metal ion-containing compound, Z represents an alkyl group, aryl group, alkoxy group, acyl group, alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl group, halogen atom or hydrogen atom. Z is preferably an electron-withdrawing group such as an aryloxycarbonyl group, an alkoxycarbonyl group, or a halogen atom in order to stabilize the metal ion-containing compound. Among them, an aryloxycarbonyl group and an alkoxycarbonyl group are more preferable in terms of solubility. . Examples of the aryloxycarbonyl group include a phenoxycarbonyl group, and the alkoxycarbonyl group has a straight chain or branched chain having 1 to 20 carbon atoms such as methoxycarbonyl, ethoxycarbonyl, pentyloxycarbonyl, 2-ethylhexyloxycarbonyl group and the like. Examples thereof include alkoxycarbonyl groups, and these alkoxycarbonyl groups may be substituted with a halogen atom, an aryl group, an alkoxy group or the like.

  R and R ′ each represents an alkyl group and an aryl group, and may be the same or different, and R and Z or R ′ and Z may combine to form a ring, but Z is a hydrogen atom. Sometimes R and R 'are not methyl groups. Examples of the alkyl group represented by Z, R and R ′ include straight-chain groups having 1 to 20 carbon atoms such as methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, t-butyl, hexyl, octyl and 2-ethylhexyl groups. An alkyl group having a chain or a branch can be exemplified, and these alkyl groups may be substituted with a halogen atom, an aryl group or an alkoxy group. Examples of the aryl group represented by Z, R and R ′ include phenyl and naphthyl groups, which may have a substituent. Examples of the alkoxy group represented by Z include linear or branched alkoxy groups having 1 to 20 carbon atoms such as methoxy, ethoxy and butoxy. Examples of the acyl group represented by Z include acetyl, propionyl, chloroacetyl, phenacetyl, and benzoyl groups. Preferred examples of the halogen atom represented by Z include a chlorine atom.

The addition amount of the metal ion-containing compound used in the present invention is usually preferably 0.5 to 20 g, more preferably 1 to 15 g per 1 m ^{2 of} the thermal transfer image receiving sheet.

  The metal ion-containing compound represented by the general formula (I) can be synthesized, for example, according to the method described in Chelate Chemistry (5) Complex Chemistry Experimental Method [I] (Edited by Nanedo).

[Middle layer]
Further, in the thermal transfer image receiving sheet, an intermediate layer may be provided between the base sheet and the image receiving layer in addition to the electric transmission according to the present invention. Examples of the function of the intermediate layer include solvent resistance performance, barrier performance, adhesion performance, white color imparting performance, hiding performance, and the like, but not limited to these, all conventionally known intermediate layers can be applied.

  In order to impart solvent resistance and barrier performance to the intermediate layer, it is preferable to use a water-soluble resin. Examples of water-soluble resins include cellulose resins such as carboxymethyl cellulose, polysaccharide resins such as starch, proteins such as casein, gelatin, agar, and polyvinyl alcohol, ethylene vinyl acetate copolymer, polyvinyl acetate, vinyl chloride, Vinyl-based copolymers such as vinyl acetate copolymer (for example, Veopa, manufactured by Japan Epoxy Resin Co., Ltd.), vinyl acetate (meth) acrylic copolymer, (meth) acrylic resin, styrene (meth) acrylic copolymer, styrene resin, etc. Examples thereof include resins, polyamide resins such as melamine resins, urea resins, and benzoguanamine resins, polyesters, polyurethanes, and the like. The water-soluble resin here is completely dissolved (particle size of 0.01 μm or less), colloidal dispersion (0.01 to 0.1 μm), or emulsion (0.1 to 1 μm) in a solvent mainly composed of water. ) Or a resin in a slurry (1 μm or more) state. Of these water-soluble resins, particularly preferred are alcohols such as methanol, ethanol, and isopropyl alcohol, and dissolution by general-purpose solvents such as hexane, cyclohexane, acetone, methyl ethyl ketone, xylene, ethyl acetate, butyl acetate, and toluene. Of course, it is a resin that does not even swell. In this sense, a resin that is completely soluble in a solvent mainly composed of water is most preferable. In particular, a polyvinyl alcohol resin and a cellulose resin are mentioned.

  In order to give adhesive performance to the intermediate layer, a urethane-based resin and a polyolefin-based resin are generally used depending on the type of the base sheet and its surface treatment. Further, when a thermoplastic resin having active hydrogen and a curing agent such as an isocyanate compound are used in combination, good adhesiveness can be obtained. In order to give the intermediate layer a white color imparting ability, a fluorescent whitening agent can be used. The fluorescent brightening agent used can be any conventionally known compound, including stilbene, distilbene, benzoxazole, styryl-oxazole, pyrene-oxazole, coumarin, aminocoumarin, imidazole, and benzimidazole. -Based, pyrazoline-based, and distyryl-biphenyl-based fluorescent whitening agents. The whiteness can be adjusted by the type and amount of the fluorescent brightener. Any method can be used as the method of adding the optical brightener. That is, a method of adding by dissolving in water, a method of adding by pulverizing and dispersing by a ball mill or a colloid mill, a method of dissolving in a high boiling point solvent and mixing with a hydrophilic colloid solution, and adding as an oil-in-water dispersion, There is a method of impregnating the polymer latex and adding it.

  Furthermore, titanium oxide may be added to the intermediate layer in order to conceal the glare of the base sheet and unevenness. Furthermore, the use of titanium oxide is preferable in that the degree of freedom in selecting a base sheet is widened. There are two types of titanium oxide: rutile type titanium oxide and anatase type titanium oxide, but considering the effect of whiteness and fluorescent whitening agent, the absorption in the ultraviolet region is shorter than rutile type. Anatase type titanium oxide is preferred. If the binder resin in the intermediate layer is aqueous and titanium oxide is difficult to disperse, use titanium oxide with a hydrophilic treatment on the surface, or disperse with a known dispersant such as a surfactant or ethylene glycol. be able to. As for the addition amount of a titanium oxide, 10-400 mass parts is preferable as a titanium oxide solid content with respect to 100 mass parts of resin solid content.

[Back layer]
The back layer may be a multilayer structure in which a plurality of layers are laminated, but the main component of the binder on the outermost layer is ethyl cellulose, hydroxy cellulose, hydroxypropyl cellulose, methyl cellulose, cellulose acetate, cellulose acetate butyrate, nitrocellulose, etc. A cellulose resin is preferred. By combining this with the conductivity measured by the salt bridge method, the antistatic performance such as judgment is further improved. Although the details are unknown, it is presumed that the charged series of the cellulosic resin is in a relatively intermediate position and the generation of charges is relatively reduced. The back layer may contain a conventionally known additive such as a conductive agent and a matting agent.

<Thermal transfer sheet>
The thermal transfer sheet according to the present invention has each dye layer containing a dye and a peelable protective transfer layer.

  FIG. 1 is a perspective view showing an example of a form of a thermal transfer sheet according to the present invention. In FIG. 1, the thermal transfer sheet 11 is formed with dye layers 13Y, 13M, and 13C corresponding to yellow (Y), magenta (M), and cyan (C) dyes on the same plane of the base sheet 12. In addition, a protective transfer layer unit 14 including a peelable protective transfer layer is provided in an area different from the dye layer in the surface order. The protective transfer layer unit 14 is configured on a base sheet 12 in the order of a non-transferable release layer 15, a protective transfer layer 16, and an adhesive layer 17. The other surface of the base sheet 2 is provided with a heat-resistant slip layer 18. The protective transfer layer 16 may be a laminate of a protective layer and an adhesive layer.

In FIG. 1, there are slight gaps between the dye layers or the protective transfer layer units 14, but the gaps may be appropriately adjusted in accordance with the control method of the thermal transfer recording apparatus. Further, in order to increase the accuracy of cueing each dye layer, it is preferable to provide a detection mark on the thermal transfer sheet, and the method of providing the detection mark is not particularly limited. Although a dye layer and a heat transferable protective transfer layer or a region where post-heating treatment is performed are shown on the same plane of the base sheet, of course, each layer may be provided on a separate support. Needless to say. In addition, when a reactive dye is used for each dye layer, the dye itself contained in the dye layer is a compound before the reaction, and strictly speaking, it cannot be said to be Y, M, or C dye, but Y, M In the sense that it is the layer for finally forming the C image, it is expressed in the same way for convenience. [Base Material Sheet]
As the base sheet used in the thermal transfer sheet according to the present invention, conventionally known materials can be used as the base sheet of the thermal transfer sheet. Specific examples of preferable base sheet include thin papers such as glassine paper, condenser paper, and paraffin paper, polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polyphenylene sulfide, polyether ketone, polyether sulfone, and other high heat resistant polyesters. Polypropylene, fluororesin, polycarbonate, cellulose acetate, polyethylene derivatives, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyamide, polyimide, polymethylpentene, ionomer and other plastic stretched or unstretched films and these materials are laminated The thing which was done is mentioned. The thickness of the substrate sheet can be appropriately selected depending on the material so that the strength, heat resistance and the like are appropriate, but usually a thickness of about 1 to 100 μm is preferably used.

  Moreover, when adhesion with the dye layer formed on the surface of the substrate sheet is poor, it is preferable to perform primer treatment or corona treatment on the surface.

[Dye layer]
The dye layer constituting the thermal transfer sheet according to the present invention is a heat sublimable colorant layer containing at least a dye and a binder resin.

<dye>
The dye-containing region used in the thermal transfer sheet according to the present invention can be two or more dye-containing regions having different hues. For example, the dye-containing region includes a yellow dye-containing region, a magenta dye-containing region, and cyan. An embodiment in which a dye-containing region is formed after the dye-containing region, and the dye-containing region is an ink layer containing a black dye, and the dye-free region is next to the region. The formed embodiment and the dye-containing region are composed of a region containing a yellow dye, a region containing a magenta dye, a region containing a cyan dye, and a region containing a black dye. The aspect etc. in which the containing area | region was formed are mentioned.

  Examples of the dye used in the heat sublimable colorant layer include all dyes such as azo, azomethine, methine, anthraquinone, quinophthalone, and naphthoquinone that are used in a heat transfer sheet of a conventional heat-sensitive sublimation transfer method. There is no particular limitation. Specific examples of yellow dyes include Holon Brilliant Yellow 6GL, PTY-52, Macrolex Yellow 6G, and red dyes such as MS Red G, Macrolex Red Violet R, Ceres Red 7B, Samaron Red HBSL, and SK. Rubin SEGL and the like, and as blue dyes, Kayaset Blue 714, Waxoline Blue AP-FW, Holon Brilliant Blue S-R, MS Blue 100, Daito Blue No. 1 etc. are mentioned.

  The heat-diffusible dye capable of forming a chelate is not particularly limited as long as thermal transfer is possible, and various known compounds can be appropriately selected and used. For example, JP-A-59-78893 Use cyan dye, magenta dye, yellow dye, etc. described in JP-A No. 59-109349, JP-A-4-94974, JP-A-4-97894, and Patent No. 2,856,225. can do.

  For example, examples of the chelate cyan dye include compounds represented by the following general formula (1).

In the general formula (1), R ₁₁ and R ₁₂ each represent a substituted or unsubstituted aliphatic group, and R ₁₁ and R ₁₂ may be the same or different. Examples of the aliphatic group include an alkyl group, a cycloalkyl group, an alkenyl group, and an alkynyl group. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an i-propyl group, and the like, and examples of the group that can replace these alkyl groups include a linear or branched alkyl group (for example, a methyl group). Group, ethyl group, i-propyl group, t-butyl group, n-dodecyl group, 1-hexylnonyl group, etc.), cycloalkyl group (for example, cyclopropyl group, cyclohexyl group, bicyclo [2.2.1]) Heptyl group, adamantyl group and the like), alkenyl group (for example, 2-propylene group, oleyl group, etc.), aryl group (for example, phenyl group, ortho-tolyl group, ortho-anisyl group, 1-naphthyl group, 9- Anthranyl group, etc.), heterocyclic groups (for example, 2-tetrahydrofuryl group, 2-thiophenyl group, 4-imidazolyl group, 2-pyridyl group, etc.), Logen atom (eg, fluorine atom, chlorine atom, bromine atom), cyano group, nitro group, hydroxy group, carbonyl group (eg, alkylcarbonyl group such as acetyl group, trifluoroacetyl group, pivaloyl group, benzoyl group, pentane) Fluorobenzoyl group, arylcarbonyl group such as 3,5-di-t-butyl-4-hydroxybenzoyl group), oxycarbonyl group (for example, methoxycarbonyl group, cyclohexyloxycarbonyl group, n-dodecyloxycarbonyl group, etc.) Aryloxycarbonyl groups such as alkoxycarbonyl group, phenoxycarbonyl group, 2,4-di-t-amylphenoxycarbonyl group, 1-naphthyloxycarbonyl group, 2-pyridyloxycarbonyl group, 1-phenylpyrazolyl-5-oxy Carbonyl group Heterocyclic oxycarbonyl group, etc.), carbamoyl group (eg, dimethylcarbamoyl group, alkylcarbamoyl group such as 4- (2,4-di-t-amylphenoxy) butylaminocarbonyl group, phenylcarbamoyl group, 1-naphthylcarbamoyl) Arylcarbamoyl group such as a group), alkoxy group (for example, methoxy group, 2-ethoxyethoxy group, etc.), aryloxy group (for example, phenoxy group, 2,4-di-t-amylphenoxy group, 4- (4- Hydroxyphenylsulfonyl) phenoxy group), heterocyclic oxy group (for example, 4-pyridyloxy group, 2-hexahydropyranyloxy group, etc.), carbonyloxy group (for example, acetyloxy group, trifluoroacetyloxy group, pivaloyloxy) Alkylcarbonyloxy groups such as benzoyl Aryloxy groups such as ruoxy groups and pentafluorobenzoyloxy groups), urethane groups (for example, alkylurethane groups such as N, N-dimethylurethane groups, N-phenylurethane groups, N- (p-cyanophenyl) urethane groups. Aryl urethane groups, etc.), sulfonyloxy groups (for example, methanesulfonyloxy groups, trifluoromethanesulfonyloxy groups, alkylsulfonyloxy groups such as n-dodecanesulfonyloxy groups, benzenesulfonyloxy groups, p-toluenesulfonyloxy groups, etc.) An arylsulfonyl group such as a dimethylamino group, a cyclohexylamino group, an alkylamino group such as an n-dodecylamino group, an anilino group, an arylamino group such as a pt-octylanilino group, etc.) , Sulfonylamino group (eg Methanesulfonylamino group, heptafluoropropanesulfonylamino group, alkylsulfonylamino group such as n-hexadecylsulfonylamino group, p-toluenesulfonylamino group, arylsulfonylamino group such as pentafluorobenzenesulfonylamino, etc.), sulfa Moylamino group (eg, alkylsulfamoylamino group such as N, N-dimethylsulfamoylamino group, arylsulfamoylamino group such as N-phenylsulfamoylamino group), acylamino group (eg, acetyl) Amino groups, alkylcarbonylamino groups such as myristoylamino groups, arylcarbonylamino groups such as benzoylamino groups, etc., ureido groups (eg, alkylureido groups such as N, N-dimethylaminoureido groups, N-phenylureido) , Arylureido groups such as N- (p-cyanophenyl) ureido group), sulfonyl groups (eg, alkylsulfonyl groups such as methanesulfonyl group and trifluoromethanesulfonyl group, arylsulfonyl groups such as p-toluenesulfonyl group, etc.) Sulfamoyl groups (eg, dimethylsulfamoyl groups, alkylsulfamoyl groups such as 4- (2,4-di-t-amylphenoxy) butylaminosulfonyl group, and arylsulfamoyl groups such as phenylsulfamoyl group) Etc.), alkylthio groups (for example, methylthio group, t-octylthio group, etc.), arylthio groups (for example, phenylthio group, etc.), heterocyclic thio groups (for example, 1-phenyltetrazol-5-thio group, 5-methyl-1) , 3,4-oxadiazole-2-thio group and the like.

  Examples of the cycloalkyl group and the alkenyl group are the same as the above substituents. Examples of the alkynyl group include 1-propyne, 2-butyne, 1-hexyne and the like.

As R ₁₁ and R ₁₂ , a group that forms a non-aromatic cyclic structure (eg, pyrrolidine ring, piperidine ring, morpholine ring, etc.) is also preferable.

R ₁₃ is preferably an alkyl group, a cycloalkyl group, an alkoxy group, or an acylamino group among the above substituents. n represents an integer of 0 to 4, and when n is 2 or more, the plurality of R ₁₃ may be the same or different.

R ₁₄ is an alkyl group, and examples thereof include a methyl group, an ethyl group, an i-propyl group, a t-butyl group, an n-dodecyl group, and a 1-hexylnonyl group. R ₁₄ is preferably a secondary or tertiary alkyl group, and preferred examples of the secondary or tertiary alkyl group include an isopropyl group, a sec-butyl group, a tert-butyl group, and a 3-heptyl group. The most preferred substituent for R ₁₄ is an isopropyl group or a tert-butyl group. The alkyl group of R ₁₄ may be substituted, but is all substituted with a substituent consisting of a carbon atom and a hydrogen atom. They are not substituted with substituents containing other atoms.

R ₁₅ is an alkyl group, and examples thereof include an n-propyl group, i-propyl group, t-butyl group, n-dodecyl group, 1-hexylnonyl group and the like. R ₁₅ is preferably a secondary or tertiary alkyl group, and preferred examples of the secondary or tertiary alkyl group include an isopropyl group, a sec-butyl group, a tert-butyl group, and a 3-heptyl group. The most preferred substituent for R ₁₅ is an isopropyl group or a tert-butyl group. The alkyl group of R15 may be substituted, but is all substituted with a substituent consisting of a carbon atom and a hydrogen atom. They are not substituted with substituents containing other atoms.

R ₁₆ represents an alkyl group, and examples thereof include n-propyl group, n-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, isopropyl group, sec-butyl group, tert-butyl group. , 3-heptyl group and the like. Particularly preferred substituents for R ₁₆ are straight-chain alkyl groups having 3 or more carbon atoms, such as n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl. And most preferably an n-propyl group or an n-butyl group. The alkyl group of R ₁₆ may be substituted, but is all substituted with a substituent consisting of a carbon atom and a hydrogen atom, and is not substituted with a substituent containing other atoms.

  Moreover, as a chelate yellow pigment | dye, the compound represented by following General formula (2) can be mentioned.

In the general formula (2), examples of each substituent represented by R ₁ and R ₂ include a halogen atom, an alkyl group (an alkyl group having 1 to 12 carbon atoms, an oxygen atom, a nitrogen atom, a sulfur atom). Alternatively, a substituent linked by a carbonyl group may be substituted, or an aryl group, alkenyl group, alkynyl group, hydroxyl group, amino group, nitro group, carboxyl group, cyano group or halogen atom may be substituted. Methyl, isopropyl, t-butyl, trifluoromethyl, methoxymethyl, 2-methanesulfonylethyl, 2-methanesulfonamidoethyl, cyclohexyl, etc.), aryl groups (for example, phenyl, 4-t-butylphenyl, 3 -Groups such as nitrophenyl, 3-acylaminophenyl, 2-methoxyphenyl), cyano group, a Lucoxyl group, aryloxy group, acylamino group, anilino group, ureido group, sulfamoylamino group, alkylthio group, arylthio group, alkoxycarbonylamino group, sulfonamido group, carbamoyl group, sulfamoyl group, sulfonyl group, alkoxycarbonyl group, Examples include a heterocyclic oxy group, an acyloxy group, a carbamoyloxy group, a silyloxy group, an aryloxycarbonylamino group, an imide group, a heterocyclic thio group, a phosphonyl group, and an acyl group.

Examples of the alkyl group and aryl group represented by R ₃ include the same alkyl groups and aryl groups represented by R ₁ and R ₂ .

Specific examples of the 5- to 6-membered aromatic ring constituted with two carbon atoms represented by Z ₁ include benzene, pyridine, pyrimidine, triazine, pyrazine, pyridazine, pyrrole, furan, thiophene and pyrazole. , Imidazole, triazole, oxazole, thiazole and the like, and these rings may further form condensed rings with other aromatic rings. These rings may have a substituent, and examples of the substituent include the same substituents represented by R ₁ and R ₂ .

  Moreover, as a chelate magenta pigment | dye, the compound represented by following General formula (3) can be mentioned.

In the general formula (3), X represents at least a bidentate chelate-forming group or group of atoms, and Y represents a group of atoms forming a 5-membered or 6-membered aromatic hydrocarbon ring or heterocycle. , R ₁ and R ₂ each represent a hydrogen atom, a halogen atom or a monovalent substituent. n represents 0, 1, 2;

  X is particularly preferably a group represented by the following general formula (4).

In the general formula (4), Z ₂ represents an atomic group necessary for forming an aromatic nitrogen-containing heterocyclic ring substituted with at least one group containing a chelatable nitrogen atom. Specific examples of the ring include pyridine, pyrimidine, thiazole, imidazole and the like. These rings may further form a condensed ring with another carbocycle (such as a benzene ring) or a heterocycle (such as a pyridine ring).

  In the general formula (3), Y represents a group of atoms forming a 5-membered or 6-membered aromatic hydrocarbon ring or heterocyclic ring, and the ring may further have a substituent, and is condensed. You may have a ring. Specific examples of the ring include 3H-pyrrole ring, oxazole ring, imidazole ring, thiazole ring, 3H-pyrrolidine ring, oxazolidine ring, imidazolidine ring, thiazolidine ring, 3H-indole ring, benzoxazole ring, benzimidazole ring, A benzothiazole ring, a quinoline ring, a pyridine ring, etc. are mentioned. These rings may further form a condensed ring with another carbocyclic ring (for example, benzene ring) or a heterocyclic ring (for example, pyridine ring). Examples of substituents on the ring include alkyl groups, aryl groups, heterocyclic groups, acyl groups, amino groups, nitro groups, cyano groups, acylamino groups, alkoxy groups, hydroxy groups, alkoxycarbonyl groups, halogen atoms, etc. The group may be further substituted.

R ₁ and R ₂ each represent a hydrogen atom, a halogen atom (for example, a fluorine atom, a chlorine atom) or a monovalent substituent, and examples of the monovalent substituent include an alkyl group, an alkoxy group, a cyano group, Examples thereof include an alkoxycarbonyl group, an aryl group, a heterocyclic group, a carbamoyl group, a hydroxy group, an acyl group, and an acylamino group.

  X represents at least a bidentate chelating group or a group of atoms, and may be any compound capable of forming a dye as the general formula (3), for example, 5-pyrazolone, imidazole, pyrazolopyrrole, pyrazolopyrazole, pyra Zoloimidazole, pyrazolotriazole, pyrazolotetrazole, barbituric acid, thiobarbituric acid, rhodanine, hydantoin, thiohydantoin, oxazolone, isoxazolone, indandione, pyrazolidinedione, oxazolidinedione, hydroxypyridone, or pyrazolopyridone are preferred .

  The SP value of the dye can also be controlled by adjusting the substituent. However, in the dye, priority is given to solubility, sensitivity, color, etc., and it is better to adjust the binder and plasticizer so as to satisfy the relationship of the present invention. preferable.

<Binder resin>
The dye layer according to the present invention contains a binder resin together with the dye.

  As the binder resin used in the dye layer, a binder resin used in a conventionally known heat-sensitive sublimation transfer type thermal transfer sheet can be used, for example, a cellulose-based resin such as a cellulose addition compound, cellulose ester, cellulose ether, Polyvinyl acetal resins such as polyvinyl alcohol, polyvinyl formal, polyvinyl acetoacetal, polyvinyl butyral, polyvinyl pyrrolidone, polyvinyl acetate, polyacrylamide, styrene resin, poly (meth) acrylic acid ester, poly (meth) acrylic acid, (meth ) Vinyl resins such as acrylic acid copolymers, rubber resins, ionomer resins, olefin resins, polyester resins and the like. Among these resins, polyvinyl butyral, polyvinyl acetoacetal or cellulose resin having excellent storage stability is preferable.

  As a binder resin for the dye layer, a reaction product of an isocyanate described in JP-B-5-78437 and a compound having active hydrogen selected from polyvinyl butyral, polyvinyl formal, polyester polyol and acrylic polyol, isocyan The reaction product in which the amount of the reaction product is 10 to 200 parts by mass with respect to 100 parts by mass of the reaction product in which the natates are diisocyanate or triisocyanate and the compound having active hydrogen; An organic solvent-soluble polymer obtained by esterifying and / or urinating an intramolecular hydroxyl group of a synthetic water-soluble polymer, a natural and / or semi-synthetic water-soluble polymer; the degree of acetylation described in JP-A-3-264393 is 2. Cellulose acetate having a total substitution degree of 4 or more and a total substitution degree of 2.7 or more; polyvinyl alcohol ( g = 85 ° C.), polyvinyl acetate (Tg = 32 ° C.), vinyl resin such as vinyl chloride / vinyl acetate copolymer (Tg = 77 ° C.), polyvinyl butyral (Tg = 84 ° C.), polyvinyl acetoacetal (Tg = 110 ° C.), polyvinyl acetal resins such as polyacrylamide (Tg = 165 ° C.), polyester resins such as aliphatic polyester (Tg = 130 ° C.), etc .; isocyanates described in JP-A-7-52564 And a reaction product of polyvinyl butyral with a vinyl alcohol moiety content of 15 to 40%, and the reaction product wherein the isocyanate is a diisocyanate or a triisocyanate; JP-A-7-32742 A phenylisocyanate-modified polyvinyl acetal resin of the general formula (I) described in JP-A-6-15 One of the isocyanate-reactive cellulose or isocyanate-reactive acetal resin described in No. 935, an isocyanate-reactive acetal resin, an isocyanate-reactive vinyl resin, an isocyanate-reactive acrylic resin, an isocyanate-reactive phenoxy resin, and Cured product of composition containing one kind of resin selected from isocyanate-reactive styrol resin and polyisocyanate compound; polyvinyl butyral resin (preferably having a molecular weight of 60,000 or more, glass transition temperature of 60 ° C. or more, more preferably 70-110 ° C., and the mass% of the vinyl alcohol portion is 10-40%, preferably 15-30%, in the polyvinyl butyral resin); acrylic modified cellulose resin, cellulose resin include ethyl cellulose, hydroxyethyl cellulose, ethyl Cellulose-based resins (preferably ethyl cellulose) such as ruhydroxycellulose, hydroxypropylcellulose, methylcellulose, cellulose acetate, and cellulose butyrate can be used.

  One of these various binder resins can be used alone, or two or more thereof can be used in combination.

  Further, the dye layer according to the present invention may contain various known additives as required in addition to the above-described dye and binder resin. The dye layer is prepared by, for example, applying an ink coating solution prepared by dissolving or dispersing the above-mentioned dye, binder resin, or other additive in an appropriate solvent on a base sheet by a known means such as a gravure coating method. Then, it can be formed by drying. The thickness of the dye layer according to the present invention can be about 0.1 to 3.0 μm, preferably about 0.3 to 1.5 μm.

(Protective transfer layer)
The thermal transfer sheet according to the present invention preferably includes a peelable protective transfer layer. The peelable protective transfer layer is a protective layer that covers the surface of the image formed by thermal transfer onto the image receiving sheet, and is mainly composed of a transparent resin layer.

  Examples of the resin forming the protective transfer layer include polyester resins, polystyrene resins, acrylic resins, polyurethane resins, acrylic urethane resins, polycarbonate resins, epoxy-modified resins of these resins, resins obtained by modifying these resins with silicone, Examples thereof include a mixture of these resins, an ionizing radiation curable resin, and an ultraviolet blocking resin. Preferred resins include polyester resins, polycarbonate resins, epoxy-modified resins, and ionizing radiation curable resins. As the polyester resin, an alicyclic polyester resin in which the diol component and the acid component have one or more alicyclic compounds is preferable. As the polycarbonate resin, an aromatic polycarbonate resin is preferable, and an aromatic polycarbonate resin described in JP-A No. 11-151867 is particularly preferable.

  Examples of the epoxy-modified resin used in the present invention include epoxy-modified urethane, epoxy-modified polyethylene, epoxy-modified polyethylene terephthalate, epoxy-modified polyphenyl sulfite, epoxy-modified cellulose, epoxy-modified polypropylene, epoxy-modified polyvinyl chloride, epoxy-modified polycarbonate, Epoxy modified acrylic, epoxy modified polystyrene, epoxy modified polymethyl methacrylate, epoxy modified silicone, copolymer of epoxy modified polystyrene and epoxy modified polymethyl methacrylate, copolymer of epoxy modified acrylic and epoxy modified polystyrene, epoxy modified acrylic and epoxy modified Examples include silicone copolymers, preferably epoxy-modified acrylic, epoxy-modified polystyrene, and epoxy-modified polymers. Methacrylate and epoxy-modified silicone, more preferably a copolymer of epoxy-modified polystyrene and epoxy-modified polymethyl methacrylate, a copolymer of epoxy-modified acrylic and epoxy-modified polystyrene, and a copolymer of epoxy-modified acrylic and epoxy-modified silicone. .

<Ionizing radiation curable resin>
An ionizing radiation curable resin can be used as the protective transfer layer, and the plasticizer resistance and scratch resistance are particularly excellent. As the ionizing radiation curable resin, known ones can be used. For example, a radically polymerizable polymer or oligomer is crosslinked and cured by irradiation with ionizing radiation, and a photopolymerization initiator is added if necessary, and an electron beam is added. Those obtained by polymerization and crosslinking with ultraviolet rays can be used.

<UV blocking resin>
The main purpose of the protective transfer layer containing the ultraviolet blocking resin is to impart light resistance to the printed material. As the ultraviolet blocking resin, for example, a resin obtained by reacting and bonding a reactive ultraviolet absorber to a thermoplastic resin or the above ionizing radiation curable resin can be used. More specifically, a conventionally known non-reactive organic ultraviolet absorber such as salicylate, benzophenone, benzotriazole, substituted acrylonitrile, nickel chelate or hindered amine is added to an addition polymerizable double bond ( Examples thereof include those in which a reactive group such as a vinyl group, an acryloyl group, a methacryloyl group), an alcoholic hydroxyl group, an amino group, a carboxyl group, an epoxy group, or an isocyanate group is introduced.

  In the present invention, as a method for forming a protective transfer layer on a substrate sheet, a coating solution in which additives such as an antistatic agent and wax are added to a synthetic resin as necessary is prepared. Examples of the method include coating and drying on a release layer already formed on a sheet using a known means such as gravure coating, gravure reverse coating, and roll coating. The thickness of the protective transfer layer to be formed is about 0.5 to 5 μm, preferably about 1 to 2 μm.

(Release layer)
The peelable protective transfer layer according to the present invention is preferably provided on the base sheet via a non-transferable release layer.

  The non-transfer mold release layer always makes the adhesive force between the base sheet and the non-transfer mold release layer sufficiently higher than the adhesive force between the non-transfer mold release layer and the protective transfer layer, And for the purpose of making the adhesive force between the non-transferring release layer and the protective transfer layer before applying heat higher than that after applying heat, (1) together with the resin binder, the average particle diameter Contains 30 to 80% by mass of inorganic fine particles of 40 nm or less, or (2) contains an alkyl vinyl ether / maleic anhydride copolymer, a derivative thereof, or a mixture thereof in a ratio of 20% by mass or more in total. Or (3) The ionomer is preferably contained in a proportion of 20% by mass or more. The non-transferable release layer may contain other additives as necessary.

  Examples of the inorganic fine particles include silica fine particles such as anhydrous silica and colloidal silica, and metal oxides such as tin oxide, zinc oxide, and zinc antimonate. The particle diameter of the inorganic fine particles is preferably 40 nm or less. If it exceeds 40 nm, the unevenness on the surface of the protective transfer layer is increased due to the unevenness on the surface of the release layer, and as a result, the transparency of the protective transfer layer is lowered, which is not preferable.

  The resin binder to be mixed with the inorganic fine particles is not particularly limited, and any resin that can be mixed can be used. For example, polyvinyl alcohol resins (PVA) of various saponification degrees; polyvinyl acetal resins; polyvinyl butyral resins; acrylic resins; polyamide resins; cellulose resins such as cellulose acetate, alkyl cellulose, carboxymethyl cellulose, hydroxyalkyl cellulose; Examples thereof include resins.

  The blending ratio (inorganic particulate / other blending components) of the inorganic particulates and other blending components mainly composed of a resin binder is preferably in the range of 30/70 or more and 80/20 or less in terms of mass ratio. When the blending ratio is less than 30/70, the effect of the inorganic fine particles becomes insufficient. On the other hand, when the blending ratio exceeds 80/20, the release layer does not become a complete film, and the base sheet and the protective transfer layer are in direct contact with each other. End up.

  Examples of the alkyl vinyl ether / maleic anhydride copolymer or derivatives thereof include those in which the alkyl group of the alkyl vinyl ether moiety is a methyl group or an ethyl group, and the maleic anhydride moiety is partially or completely alcohol (for example, methanol, ethanol, etc.). , Propanol, isopropanol, butanol, isobutanol and the like) can be used.

  The release layer may be formed only with an alkyl vinyl ether / maleic anhydride copolymer, a derivative thereof, or a mixture thereof, but for the purpose of adjusting the peeling force between the release layer and the protective transfer layer, other layers may be used. These resins or fine particles may be further added. In that case, it is desirable that the release layer contains 20% by mass or more of an alkyl vinyl ether / maleic anhydride copolymer, a derivative thereof, or a mixture thereof. When the content is less than 20% by mass, the effect of the alkyl vinyl ether / maleic anhydride copolymer or its derivative cannot be sufficiently obtained.

  The resin or fine particles blended in the alkyl vinyl ether / maleic anhydride copolymer or its derivative is not particularly limited as long as it can be mixed and can provide high film transparency at the time of film formation, and any material can be used. be able to. For example, the above-mentioned inorganic fine particles and resin binders that can be mixed with the inorganic fine particles are preferably used.

  As the ionomer, for example, Surlyn A (manufactured by DuPont), Chemipearl S series (manufactured by Mitsui Petrochemical Co., Ltd.) or the like can be used. Further, for example, the above-mentioned inorganic fine particles, a resin binder that can be mixed with the inorganic fine particles, or other resins and fine particles can be further added to the ionomer.

  In order to form a non-transferable release layer, a coating solution containing any of the above components (1) to (3) in a predetermined blending ratio is prepared, and the coating solution is subjected to a gravure coating method or gravure reverse. It apply | coats on a base material sheet | seat by well-known techniques like a coating method, and dries an application layer. The thickness of the non-transferable release layer is usually about 0.1 to 2 μm after drying.

  The protective transfer layer laminated on the base sheet with or without the non-transfer release layer may have a multilayer structure or a single layer structure. In the case of a multi-layer structure, in addition to the main protective transfer layer as a main component for imparting various durability to the image, a protective transfer layer is used to increase the adhesion between the protective transfer layer and the image receiving surface of the printed material. May be provided with an adhesive layer disposed on the outermost surface, an auxiliary protective transfer layer, or a layer for adding a function other than the original function of the protective transfer layer (for example, an anti-counterfeit layer, a hologram layer). . The order of the main protective transfer layer and the other layers is arbitrary, but in general, other layers are provided between the adhesive layer and the main protective transfer layer so that the main protective transfer layer becomes the outermost surface of the image receiving surface after transfer. Place.

(Adhesive layer)
An adhesive layer is preferably formed on the outermost surface of the protective transfer layer. The adhesive layer should be formed of a resin having good adhesiveness when heated, such as acrylic resin, vinyl chloride resin, vinyl acetate resin, vinyl chloride / vinyl acetate copolymer resin, polyester resin, polyamide resin. Can do. In addition to the above resin, the above-mentioned ionizing radiation curable resin, ultraviolet blocking resin and the like may be mixed as necessary. The thickness of the adhesive layer is usually 0.1 to 5 μm.

  In order to form a protective transfer layer on a non-transferable release layer or on a substrate sheet, for example, a protective transfer layer coating solution containing a protective transfer layer forming resin, or an adhesive layer containing a thermal adhesive resin A coating solution for forming a coating solution and other layers to be added according to need is prepared in advance, and these are applied in a predetermined order on a non-transferable release layer or a substrate sheet and dried. Each coating solution may be applied by a conventionally known method. Moreover, you may provide an appropriate primer layer between each layer.

[Others]
<UV absorber>
It is preferable that at least one layer of the protective transfer layer unit (peeling layer, protective transfer layer and adhesive layer) contains an ultraviolet absorber, but when it is contained in the transparent resin layer, after the transfer of the protective transfer layer Since the transparent resin layer is present on the outermost surface of the printed material, the effect is reduced with time due to the influence of the environment or the like over a long period of time. Therefore, the transparent resin layer is particularly preferably contained in the heat-sensitive adhesive layer.

  Examples of the ultraviolet absorber include salicylic acid-based, benzophenone-based, benzotriazole-based, and cyanoacrylate-based ultraviolet absorbers. Tinuvin 312, Tinuvin 315 (Ciba Geigy), Sumisorb-110, Sumisorb-130, Sumsorb-140, Sumisorb-200, Sumsorb-250, Sumisorb-300, Sumisorb-320, Sumisorb-340, 350 Sumisorb-400 (above, manufactured by Sumitomo Chemical Co., Ltd.), Mark LA-32, Mar LA-36, Mark 1413 (or, Adeka Argus Chemical Co., Ltd.) available on the market under the trade names such as, any can be used in the present invention.

  Further, a random copolymer having a Tg of 60 ° C. or higher, preferably 80 ° C. or higher, in which a reactive ultraviolet absorber and an acrylic monomer are randomly copolymerized may be used.

  The above-mentioned reactive ultraviolet absorber is a conventionally known salicylate-based, benzophenone-based, benzotriazole-based, substituted acrylonitrile-based, nickel chelate-based, hindered amine-based non-reactive ultraviolet absorber, for example, vinyl group, acryloyl group, Addition-polymerizable double bonds such as methacryloyl groups, or those having introduced an alcoholic hydroxyl group, amino group, carboxyl group, epoxy group, isocyanate group or the like can be used. Specifically, UVA635L, UVA633L (above, manufactured by BASF Japan Ltd.), PUVA-30M (manufactured by Otsuka Chemical Co., Ltd.) and the like can be obtained from the market, and any of them can be used in the present invention. .

  The amount of the reactive ultraviolet absorbent in the random copolymer of the reactive ultraviolet absorbent and the acrylic monomer as described above is in the range of 10 to 90 mass%, preferably 30 to 70 mass%. Moreover, the molecular weight of such a random copolymer can be about 5000-250,000, Preferably it can be about 9000-30000. The above-described ultraviolet absorber and the random copolymer of the reactive ultraviolet absorber and the acrylic monomer may be contained alone or in combination. The addition amount of the random copolymer of the reactive ultraviolet absorber and the acrylic monomer is preferably 5 to 50% by mass with respect to the layer to be contained.

<Light resistance>
In addition to the ultraviolet absorber, another light-proofing agent may be included. Here, the light-proofing agent is an agent that prevents or alters the degradation or decomposition of the dye by absorbing or blocking the action of altering or decomposing the dye, such as light energy, thermal energy, and oxidizing action. In addition to the inhibitors, there are antioxidants and light stabilizers known as additives for conventional synthetic resins. In this case, it may be contained in at least one of the protective transfer layers, that is, at least one of the release layer, the transparent resin layer, and the heat-sensitive adhesive layer, but is particularly preferably contained in the heat-sensitive adhesive layer.

<Antioxidant>
Examples of the antioxidant include primary antioxidants such as phenols, monophenols, bisphenols, and amines, or secondary antioxidants such as sulfur and phosphorus. Examples of the light stabilizer include hindered amines.

  Although the usage-amount of the light-proofing agent containing said ultraviolet absorber is not specifically limited, Preferably it is 0.05-10 mass parts per 100 mass parts of resin which forms the layer to contain, Preferably it is a ratio of 3-10 mass parts Used in. If the amount used is too small, it is difficult to obtain an effect as a light-proofing agent.

  In addition to the above light-proofing agent, for example, various additives such as a fluorescent brightening agent and a filler can be simultaneously added to the adhesive layer in an appropriate amount.

  The transparent resin layer of the protective transfer layer transfer sheet may be provided alone on the base sheet, or may be provided in the surface order with the ink layer of the thermal transfer sheet.

[Heat resistant slipping layer]
In the thermal transfer sheet according to the present invention, it is preferable to provide a heat-resistant slipping layer on the surface opposite to the dye layer with the base sheet interposed therebetween.

  The heat resistant slipping layer is provided for the purpose of preventing thermal fusion between a heating device such as a thermal head and a base sheet, smooth running, and removing deposits on the thermal head.

  Examples of the resin used for the heat resistant slipping layer 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, and polyvinyl. Vinyl resins such as acetal and polyvinyl pyrrolidone, acrylic resins such as polymethyl methacrylate, polyethyl acrylate, polyacrylamide, and acrylonitrile-styrene copolymers, polyimide resins, polyamide resins, polyamideimide resins, polyvinyltoluene resins, polymers A single or mixture of natural or synthetic resins such as malon indene resin, polyester resin, polyurethane resin, silicone-modified or fluorine-modified urethane is used. It is. In order to further improve the heat resistance of the heat resistant slipping layer, among the above resins, a resin having a hydroxyl group-based reactive group is used, and a polyisocyanate or the like is used in combination as a crosslinking agent. It is preferable to do.

  Further, in order to impart slidability with the thermal head, a solid or liquid release agent or lubricant may be added to the heat-resistant slip layer to provide heat-resistant slip. Examples of the release agent or lubricant include various waxes such as polyethylene wax and paraffin wax, higher aliphatic alcohols, organopolysiloxanes, anionic surfactants, cationic surfactants, amphoteric surfactants, nonionic surfactants. Activators, fluorine surfactants, metal soaps, organic carboxylic acids and derivatives thereof, fluorine resins, silicone resins, fine particles of inorganic compounds such as talc, silica, and the like can be used. The amount of the lubricant contained in the heat resistant slipping layer is 5 to 50% by mass, preferably about 10 to 30% by mass. The thickness of such a heat-resistant slipping layer can be about 0.1 to 10 μm, preferably about 0.3 to 5 μm.

  When the protective transfer layer unit is a laminate of a protective transfer layer and an adhesive layer, the adhesive layer serves to facilitate the transfer of the protective transfer layer to the transfer target. As an adhesive for forming this adhesive layer, it is possible to use a hot-melt adhesive such as acrylic, styrene acrylic, vinyl chloride, styrene-vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate copolymer. it can. The adhesive layer can be formed by known means such as gravure coating, gravure reverse coating, roll coating, etc., and the thickness of the adhesive layer is preferably about 0.1 to 5 μm.

(Image forming method)
As the thermal transfer recording apparatus used in the image forming method of the present invention, for example, a thermal transfer recording apparatus as shown in FIG. 2 can be used. In FIG. 2, 21 is a thermal transfer sheet supply roll, 11 is a thermal transfer sheet, 22 is a take-up roll for winding the used thermal transfer sheet 11, 23 is a thermal head, 24 is a platen roller, 1 is a thermal head 23 and a platen roller. 24 is a thermal transfer image receiving sheet inserted in between.

  A process for forming an image using the thermal transfer recording apparatus shown in FIG. 2 and using, for example, the thermal transfer sheet shown in FIG. 1 will be described. First, the dye layer 13Y containing the yellow dye in FIG. 1 of the thermal transfer sheet and the image receiving layer of the thermal transfer image receiving sheet are overlapped, and the yellow dye in the dye layer 13Y is transferred to the image receiving sheet according to the image data by applying heat from the thermal head 23. A yellow image is then formed, and then the magenta dye is transferred imagewise in the same manner from the dye layer 13M containing the magenta dye on the yellow image, and then the cyan dye is contained on the transferred image. In the same manner, the cyan dye is transferred in an image-like manner from the dye layer 13C, and finally, the protective transfer layer unit 14 including a transferable protective transfer layer is thermally transferred from the thermal transfer sheet to the entire surface of the image to complete the image formation To do.

  In the thermal transfer recording apparatus used in the present invention, it is preferable that glossy tone and matte tone control can be selected in the same apparatus because a printed product having a desired surface property can be obtained with one model. The selection method is not particularly limited. For example, control data corresponding to the glossy tone and matte tone of the present invention is held in the thermal transfer recording apparatus, the control data selected by a simple operation of the operator is read, and the control unit is controlled according to the data. Alternatively, when a personal computer is connected to the recording device, the control data may be held on the personal computer side and the selected control data may be sent to the recording device by a simple operation by the operator. In addition, when heating with a heat roller, a material that alters the surface, for example, a release sheet that gives gloss, or a sheet with unevenness for matting is applied to the surface of the image receiving layer after image recording. Accordingly, a recording body having a different surface can be obtained by heating with a heat roller from the back of the sheet.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, this invention is not limited to these. Unless otherwise specified, “%” in the examples represents “mass%”.

Example 1
[Preparation of thermal transfer image receiving sheet]
As the base sheet, synthetic paper (YUPOFPG # 150, manufactured by Oji Yuka Co., Ltd.) having a thickness of 150 μm is used, and an image-receiving layer coating solution having the following composition is dried on the one side by a wire bar method at 3.0 g / m. Coating and drying (110 ° C., 30 seconds) were performed at a ratio of ² to form an image receiving layer, which was allowed to stand at room temperature for 12 hours or more to obtain thermal transfer image receiving sheets 101 to 142.

<Preparation of image-receiving layer coating solution>
Image-receiving layer binder (Tables 2 and 3) 20.0 parts by mass Plasticizer (Tables 2 and 3) Tables 2 and 3
Metal ion-containing compound (MS-1 * 1) 8.0 parts by mass Vinyl-modified silicone (X-62-1212, manufactured by Shin-Etsu Chemical Co., Ltd.) 2.0 parts by mass Catalyst: CAT PLR-5 (manufactured by Shin-Etsu Chemical Co., Ltd.) 1.0 part by mass Catalyst: CAT PL-50T (manufactured by Shin-Etsu Chemical Co., Ltd.) 1.2 parts by mass Solvent: 39.0 parts by mass of methyl ethyl ketone Solvent: 39.0 parts by mass of toluene * 1) MS-1: Ni ²⁺ [ C ₇ H ₁₅ COC (COOCH ₃ ) ═C (CH ₃ ) O ⁻ ] ₂
[Preparation of thermal transfer sheet]
(Preparation of support A with back coat layer)
After applying and drying a back coat layer coating solution 1 having the following composition on one surface of a polyethylene terephthalate film with a thickness of 4.5 μm with an easy-contact layer (Lumirror manufactured by Toray Industries, Inc.), A support A having a back coat layer with a dry film thickness of 1.0 μm was prepared by heat-curing treatment.

<Preparation of backcoat layer coating solution 1>
Polyvinyl butyral resin (Sekisui Chemical Co., Ltd., ESREC BX-1) 3.5 parts Phosphate ester surfactant (Daiichi Kogyo Seiyaku Co., Ltd., PRISURF A208S)
3.0 parts Phosphate ester surfactant (manufactured by Toho Chemical Co., Ltd., Phosphanol RD720)
0.3 part polyisocyanate (Dainippon Ink & Chemicals, Barnock D750-45)
19.0 parts Talc (manufactured by Nippon Talc, Y / X = 0.03) 0.2 parts Methyl ethyl ketone 35.0 parts Toluene 35.0 parts (Formation of dye layer)
On the surface opposite to the back coat surface of the support A with the back coat layer, a dye coating solution (dry film thickness is 1 μm) having the following composition is applied and dried (100 ° C., 60 seconds) by the wire bar method. Then, a dye layer was formed and allowed to stand at room temperature for 12 hours or more to prepare thermal transfer sheets 1 to 4.

<Dye coating solution>
Dye (Tables 2 and 3) 4.5 parts by mass Polyvinyl acetoacetal resin (manufactured by Sekisui Chemical Co., Ltd., ESREC KS-5)
5.0 parts by mass Urethane-modified silicone resin (Dairoma SP-2105, manufactured by Dainichi Seika Co., Ltd.)
0.5 parts by mass Methyl ethyl ketone 45.0 parts by mass Toluene 45.0 parts by mass

  Details of the compounds abbreviated in Tables 2 and 3 are shown in Table 1.

(Image formation)
Resistor shape is square (main scanning direction length 80 μm × sub-scanning direction length 120 μm), 300 dpi (hereinafter, dpi represents the number of dots per 2.54 cm) mounted on a thermal transfer apparatus equipped with a thermal head. The image receiving layer of the thermal transfer image receiving sheet and the dye layer of the thermal transfer sheet are set to overlap each other in the combinations shown in Tables 2 and 3, and the applied energy range of 5 to 80 mJ / mm ² while being pressed by the thermal head and the platen roll. The image forming products 101 to 140 are step patterns that are sequentially increased at a feed rate of 10 msec / line, a feed length per line of 85 μm, and heated from the back side of the ink layer to transfer the dye onto the image receiving layer. Was made.

(Light resistance test of printed matter)
Xenon arc irradiation (accumulated irradiation amount = 90 KJ / m ² , irradiance = 0.35 W / m ²⁾ , black panel with xenon arc light resistance tester (Atlas Ci35A-UV weather meter, manufactured by Atlas Co., Ltd.) Temperature = 64 ° C., dry bulb humidity = 43 ° C., relative humidity = 25%), and the residual rate defined by the following equation was determined from the print density before and after irradiation. In addition, the step where the optical density before irradiation is around 1.0 was measured. The results are shown in Tables 2 and 3.

  Residual rate (%) = (reflection density after irradiation / reflection density before irradiation) × 100

  From Table 2, it can be seen that in the image forming method of the present invention, the light resistance of the image is high even when the configuration of the image receiving layer of the thermal transfer image receiving sheet and the type of transfer dye of the thermal transfer sheet are changed.

Example 2
[Preparation of thermal transfer image receiving sheet]
Thermal transfer image receiving sheets 201 to 211 were prepared according to the following contents.

(Preparation of support B)
A coated paper (US basis weight 157 g / m ² , OK Topcoat S, manufactured by Oji Paper Co., Ltd.) was used as a support for the image-receiving sheet. As a high density polyethylene (J-Rex LZ0139-2, density 0.952, Nippon Polyolefin Co., Ltd.) blended with 15% by mass of an ethylene-α olefin copolymer (Tuffmer A-4085, manufactured by Mitsui Petrochemical Co., Ltd.) Hereinafter, this is abbreviated as HDPE) and polypropylene (J-Aroma LR711-5, density 0.905, manufactured by Nippon Polyolefin Co., Ltd., hereinafter abbreviated as PP), and HDPE by a co-extrusion coating method using a known multilayer T die. Two layers were coextruded and laminated so that the side was in contact with the coated paper. In addition, after the corona discharge treatment is applied to the PP surface that is on the outside, the back layer coating solution 1 having the following composition is applied and dried so that the dry solid content is 1.5 g / m ² , Support B was prepared. The back surface resin layer was processed so that the HDPE layer of the ethylene-α-olefin copolymer blend was 14 μm and the PP layer was 19 μm, for a total of 33 μm.

<Preparation of backside layer coating solution 1>
Acrylic resin (Mitsubishi Rayon Co., Ltd., BR-85) 19.8 parts by mass Nylon filler (Shinto Paint Co., Ltd. MW-330) 0.6 parts by mass Methyl ethyl ketone 39.8 parts by mass Toluene 39.8 parts by mass (Preparation of thermal transfer image receiving sheet)
On the other hand, a foamed polypropylene sheet (35 MW846 Mobile Plastics Europe) having a thickness of 35 μm was used as the resin layer having fine voids, and an intermediate layer coating solution and an image receiving layer coating solution having the following composition were formed on one surface thereof. Then, by the gravure reverse coating method, the foamed polypropylene sheet in which the intermediate layer and the image receiving layer were laminated was prepared by sequentially coating and drying so that the coating film thickness when dried was 1 μm and 3 μm, respectively.

  Next, the surface of the expanded polypropylene sheet on which the intermediate layer and the image receiving layer are not provided (expanded polypropylene sheet surface) and the surface of the support B on which the back resin layer is not provided (coated paper surface) are described below. The thermal transfer image receiving sheets 201 to 211 were prepared by bonding with a dry laminate method using an adhesive having a composition.

<Preparation of intermediate layer coating solution>
Urethane resin (Nipporan 5199, manufactured by Nippon Polyurethane Co., Ltd.) 5.7 parts by mass Titanium oxide (TCA888, manufactured by Tochem Products) 11.4 parts by mass Fluorescent whitening agent (Ubitex OB, manufactured by Ciba Geigy Japan) 0.2 Mass parts Isocyanate (Takenate A-14, manufactured by Takeda Pharmaceutical Company Limited) 2.0 mass parts Methyl ethyl ketone 15.5 mass parts Toluene 15.5 mass parts Isopropyl alcohol 7.7 mass parts <Preparation of image-receiving layer coating solution>
Image-receiving layer binder (Table 4) 20.0 parts by mass Plasticizer (Table 4) Table 4
Metal ion-containing compound (MS-1) 8.0 parts by mass Vinyl-modified silicone (X-62-1212, manufactured by Shin-Etsu Chemical Co., Ltd.) 2.0 parts by mass Catalyst: CAT PLR-5 (manufactured by Shin-Etsu Chemical Co., Ltd.) 0 parts by mass Catalyst: CAT PL-50T (manufactured by Shin-Etsu Chemical Co., Ltd.) 1.2 parts by mass Solvent: 39.0 parts by mass of methyl ethyl ketone Solvent: 39.0 parts by mass of toluene [Preparation of thermal transfer sheet]
A yellow dye coating solution 1, a magenta dye coating solution 1, and a cyan dye coating solution 1 having the following composition are used on the surface opposite to the back coat surface of the support A with a back coat layer produced in Example 1. As shown in FIG. 1, each formed dye layer (dry film thickness is 1 μm) and the following multilayer constitution protective transfer layer (non-transferable release layer / protective layer / adhesive layer three-layer constitution) are formed by a gravure method. A thermal transfer sheet 2 was prepared.

[Each dye layer]
<Yellow dye coating solution 1>
Post chelate dye (Y-1) 4.5 parts by mass Polyvinyl acetoacetal resin (manufactured by Sekisui Chemical Co., Ltd., ESREC KS-5)
5.0 parts by mass Urethane-modified silicone resin (Dairoma SP-2105, manufactured by Dainichi Seika Co., Ltd.)
0.5 parts by mass Methyl ethyl ketone 45.0 parts by mass Toluene 45.0 parts by mass <Magenta dye coating solution 1>
Post-chelate dye (M-1) 4.0 parts by mass Polyvinyl acetoacetal resin (manufactured by Sekisui Chemical Co., Ltd., ESREC KS-5)
5.5 parts by mass Urethane-modified silicone resin (Dairoma SP-2105, manufactured by Dainichi Seika Co., Ltd.)
0.5 parts by mass Methyl ethyl ketone 45.0 parts by mass Toluene 45.0 parts by mass <Cyan dye coating solution>
Post-chelate dye (C-1) 4.0 parts by mass Polyvinyl acetoacetal resin (manufactured by Sekisui Chemical Co., Ltd., ESREC KS-5)
5.5 parts by mass Urethane-modified silicone resin (Dairoma SP-2105, manufactured by Dainichi Seika Co., Ltd.)
0.5 parts by mass Methyl ethyl ketone 45.0 parts by mass Toluene 45.0 parts by mass

[Multi-layer protective transfer layer]
(Non-transferable release layer)
A non-transferable release layer coating solution 1 having the following composition is applied to the portion of the thermal transfer sheet 2 that has not been coated with the following composition by a gravure coating method, and the solid content after drying is 0.5 g / m ^2. Thus, it was applied and dried to form a non-transferable release layer.

<Non-transferable release layer coating solution 1>
Colloidal silica (Snowtex 50 manufactured by Nissan Chemical Co., Ltd.) 1.5 parts by mass Polyvinyl alcohol 4.0 parts by mass Deionized water 3.0 parts by mass Denatured ethanol 10 parts by mass (Protective transfer layer)
On the formed non-transferable release layer, a protective transfer layer coating solution 1 having the following composition was applied and dried by a gravure coating method so that the solid content after drying was 2.0 g / m ² . A protective transfer layer was formed.

<Protective transfer layer coating solution 1>
Acrylic resin 35 parts by weight Vinyl chloride-vinyl acetate copolymer 15 parts by weight Polyethylene wax 0.3 part by weight Polyester resin 0.1 part by weight Methyl ethyl ketone 40 parts by weight Toluene 40 parts by weight Zinc antimonate (Sellnax manufactured by Nissan Chemical Co., Ltd.) ) 20 parts by mass (adhesive layer)
On the protective transfer layer thus formed, the adhesive layer coating liquid 1 having the following composition is applied and dried by a gravure coating method so that the solid content after drying is 2.0 g / m ^2. Formed.

<Adhesive layer coating solution 1>
Vinyl chloride-vinyl acetate copolymer 20 parts by mass Methyl ethyl ketone 100 parts by mass Toluene 100 parts by mass By the above, the protective transfer layer, which is a laminate of the protective transfer layer and the adhesive layer, can be peeled off on the non-transferable release layer A provided multi-layer protective transfer layer was prepared.

  Using the thermal transfer sheet 2 and the thermal transfer image receiving sheets 201 to 211 produced as described above, using a sublimation thermal transfer printer (manufactured by Konica Minolta Photo Imaging Co., Ltd., RC-602 type), gradation values that are sequentially increased every 15 gradations. , Yellow, magenta, cyan, and neutral (overlapping three colors of yellow, magenta, and cyan) were transferred, and then a transparent protective layer was transferred onto the image to form image formed products 201 to 211. . A light resistance test was conducted in the same manner as in Example 1. In addition, the step where the optical density before the irradiation of neutral was around 1.0 was measured. The results are shown in Table 4.

  From Table 4, it can be seen that in the image forming method of the present invention, the light resistance of the image is high even in the case of three colors.

It is a perspective view which shows an example of the thermal transfer sheet which concerns on this invention. It is a schematic diagram showing an example of a thermal transfer recording apparatus used in the image forming method of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Thermal transfer sheet 12 Base material sheet 13Y, 13M, 13C Dye layer 14 Protective transfer layer unit 15 Non-transferring peeling layer 16 Protective transfer layer 17 Adhesive layer 21 Heat transfer sheet supply roll 22 Winding up the used thermal transfer sheet Roll 23 Thermal head 24 Platen roller

Claims (7)

A thermal transfer image-receiving sheet having an image-receiving layer containing at least a plasticizer and a binder resin on a substrate, wherein the SP value of the plasticizer is Sh, the SP value of the binder resin is Sb, and the plasticizer and the binder resin When the average SP value of Sa is Sa and the SP value of the transfer dye used for the thermal transfer sheet is Sd, a thermal transfer image receiving sheet and a thermal transfer sheet satisfying the following formulas (1) and (2) are used, Sh, Sb, Sa, Sd A thermal transfer image forming method, comprising:
Formula (1) | Sa-Sd | ≦ 3
Formula (2) | Sh-Sb | ≦ 8 The thermal transfer image forming method according to claim 1, wherein SP values of all transfer dyes used in the thermal transfer sheet satisfy | Sa−Sd | ≦ 3. The thermal transfer image forming method according to claim 2, wherein SP values of all transfer dyes used in the thermal transfer sheet satisfy | Sa−Sd | ≦ 2. The thermal transfer image forming method according to claim 1, wherein the plasticizer used for the thermal transfer sheet is a compound having an ester bond. The thermal transfer image forming method according to claim 1, wherein the plasticizer used in the thermal transfer sheet is a phosphate ester. The thermal transfer image forming method according to claim 1, wherein the image receiving layer of the thermal transfer image receiving sheet contains a metal ion-containing compound capable of forming a chelate compound with a transfer dye. An image formed product obtained by the thermal transfer image forming method according to claim 1.

Images