JP2007268969A - Thermal transfer image receiving sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermal transfer image receiving sheet which has good releasing properties with a thermal transfer sheet and can make printing density high even when printing speed of thermal transfer is made higher in the thermal transfer image receiving sheet utilizing a post chelate form. <P>SOLUTION: In the thermal transfer image receiving sheet provided with a dye receiving layer comprising a metal ion-containing compound which can react with a thermal diffusing dye which can chelate on at least one face of a substrate, the dye receiving layer comprises a radiation-curable resin having dye receiving properties, and the radiation-curable resin is preferably an acryl-modified polyvinyl butyral resin with (meth)acryloyl group. Even when accompanied with speed-up of printing speed for thermal transfer, heat applied on a thermal head becomes to a higher temperature, there exists no possibility of heat fusion with the thermal transfer sheet, and transfer density of a printed article can be kept high, and the printed article excellent in such durability as heat resistance and light resistance can be obtained. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a thermal transfer image receiving sheet used for recording by a sublimation thermal transfer system.

  One of various printing methods for forming an image is thermal sublimation transfer in which a dye in a color material layer is sublimated and diffused by heat and transferred to an image receiving sheet. In such heat-sensitive sublimation transfer, a thermal head of a printer is usually used as a heating means, and a large number of color dots whose heating amounts of three colors or four colors are adjusted by heating for a very short time are received by the thermal transfer image receiving sheet. It is transferred to a layer and the full color of the original is reproduced with multicolored dots. The image formed in this way is very clear and excellent in transparency because the coloring material used is a dye, so the resulting image is excellent in reproducibility and gradation of intermediate colors, It is possible to form a high-quality image similar to a conventional image by offset printing or gravure printing and comparable to a full-color photographic image.

  However, the thermal sublimation transfer method described above is excellent in forming a gradation image because the amount of dye transfer can be controlled in dot units depending on the amount of energy applied, but the formed image is based on ordinary printing ink. Unlike the above, the coloring material is not a pigment but a dye having a relatively low molecular weight, and since there is no vehicle, there is a disadvantage that it is inferior in durability such as light resistance, weather resistance and abrasion resistance.

  As a means for improving the above drawbacks, a method using a reactive dye that forms an image by reacting a compound in a colorant layer with a compound in a receiving layer by thermal transfer has been proposed. For example, Patent Documents 1 to 4 use a thermal transfer sheet using a thermal diffusible dye as a compound to be contained on the color material layer side, and a thermal transfer image receiving sheet using a metal ion-containing compound as a compound to be contained in the receiving layer. A method of forming an image by reacting them after thermal transfer to form a heat diffusible dye-metal ion-containing compound complex (hereinafter sometimes referred to as a post-chelation method) is disclosed.

  The image formed by the post-chelation method is less susceptible to dye fading and bleeding even when left at a high temperature and high humidity for a long time, and is excellent in light resistance as compared with an image obtained by a conventional method. . However, in recent years, there has been a demand for increasing the printing speed of thermal transfer printers, and the heat applied to the thermal head has been increased. Therefore, even if the thermal transfer image receiving sheet described in the above patent document is used, there is a problem that thermal fusion between the thermal transfer sheet and the thermal transfer image receiving sheet may occur. Further, when the softening point of the resin constituting the receiving layer is increased in order to prevent this thermal fusion, there is a problem that the transfer density of the obtained thermal transfer print product is lowered. In addition, in order to prevent the above heat fusion, for example, a method of adding a release agent to the receiving layer has been tried, but the release property between the thermal transfer image receiving sheet and the thermal transfer sheet is still insufficient. .

JP 59-78893 A JP 59-109394 A Japanese Unexamined Patent Publication No. 60-2398 JP 2000-263828 A

  The present invention has been made in view of the above problems, and in a thermal transfer image receiving sheet using a post-chelation method, the release property from the thermal transfer sheet is good even when the thermal transfer printing speed is increased. Another object of the present invention is to provide a thermal transfer image receiving sheet capable of increasing the print density.

  The present invention relates to a thermal transfer image-receiving sheet comprising a dye-receiving layer containing a metal ion-containing compound capable of reacting with a chelatable heat-diffusible dye on at least one surface of a substrate, wherein the dye-receiving layer contains the dye-receiving layer. It contains the radiation curable resin which has the property. The radiation curable resin is preferably an acrylic-modified polyvinyl butyral resin having a (meth) acryloyl group.

（式中におけるＲ¹は、水素原子又はアセチル基を表し、Ｒ²は、（メタ）アクリロイル基を有する基であり、式中のｌ、ｍ、およびｎの合計を１００とした場合に、ｌは４０〜８５、ｍは１５〜５０、ｎは０〜１５の整数である。） Moreover, it is preferable that the acrylic modified polyvinyl butyral resin having the (meth) acryloyl group is a resin represented by the following chemical formula.

(In the formula, R ¹ represents a hydrogen atom or an acetyl group, and R ² is a group having a (meth) acryloyl group. When the total of l, m, and n in the formula is 100, l Is 40 to 85, m is an integer of 15 to 50, and n is an integer of 0 to 15.)

  The present invention relates to a thermal transfer image-receiving sheet comprising a dye-receiving layer containing a metal ion-containing compound capable of reacting with a chelatable heat-diffusible dye on at least one surface of a substrate, wherein the dye-receiving layer contains the dye-receiving layer. In addition, the radiation-curable resin is preferably an acrylic-modified polyvinyl butyral resin having a (meth) acryloyl group, thereby increasing the printing speed of thermal transfer. Along with this, even if the heat applied to the thermal head is high, the transfer layer of the printed matter obtained by thermal transfer can be maintained at a high level without heat fusing with the thermal transfer sheet because the heat resistance of the receiving layer is high. A printed material having excellent durability such as heat resistance, moisture resistance and light resistance was obtained.

  The present invention relates to a thermal transfer image receiving sheet used for recording by a sublimation thermal transfer system. This will be described in detail below.

  For example, as shown in FIG. 1, the thermal transfer image-receiving sheet of the present invention has at least a substrate 1 and a dye-receiving layer 2 formed on the substrate 1. The thermal transfer image-receiving sheet of the present invention is disposed, for example, as shown in FIG. 2, with the receiving layer 2 of the thermal transfer image-receiving sheet 3 and the dye layer 12 of the thermal transfer sheet 11 provided with the dye layer 12 on the substrate 10 facing each other. In this state, by applying heat from the thermal head 13 of the printing apparatus, the dye sublimated from the dye layer 12 moves to the dye receiving layer 2 and an image is printed on the thermal transfer image receiving sheet 3.

  As described above, when the heat resistance of the receiving layer of the thermal transfer image-receiving sheet is low, the dye layer and the receiving layer are thermally fused by heat from the thermal head, and only the dye is received by the receiving unit. Difficult to move to layer. However, in the present invention, since a radiation curable resin is used for the receiving layer of the thermal transfer image-receiving sheet, the crosslinking density of the resin in the receiving layer can be increased, and the heat resistance It can be made excellent. Therefore, when printing on the thermal transfer image-receiving sheet by the sublimation thermal transfer system, the receiving layer and the dye layer of the thermal transfer sheet are not thermally fused even if the heat applied from the thermal head is high. Therefore, a thermal transfer image receiving sheet capable of recording with high definition can be obtained.

  In the present invention, the dye-receiving layer contains a metal ion-containing compound capable of reacting with a chelatable heat-diffusible dye, so that a heat-diffusible dye-metal ion-containing compound complex is formed. Thus, even when left at high temperature and high humidity for a long time, the dye does not easily fade or bleed and has excellent light resistance.

Further, in the present invention, since a radiation curable resin is used for the receiving layer, it is not necessary to perform a thermosetting step or the like when manufacturing a thermal transfer image receiving sheet. Therefore, it is possible to efficiently form the receiving layer, and there is an advantage that a preferable thermal transfer image receiving sheet can be obtained from the viewpoints of production efficiency and cost.
The thermal transfer image receiving sheet of the present invention will be described below for each configuration.

<Base material>
The substrate 1 used in the thermal transfer image receiving sheet of the present invention will be described. The substrate used in the present invention is not particularly limited as long as it can form a dye-receiving layer, but has a role of holding the dye-receiving layer and can withstand heat applied during image formation. It is desirable to have mechanical characteristics that do not hinder handling. The material of such a substrate is appropriately selected according to the type of thermal transfer image-receiving sheet, for example, polyester, polyarylate, polycarbonate, polyurethane, polyimide, polyetherimide, cellulose derivative, polyethylene, ethylene / vinyl acetate copolymer Coalescence, polypropylene, polystyrene, acrylic, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyvinyl butyral, nylon, polyether ether ketone, polysulfone, polyether sulfone, tetrafluoroethylene perfluoroalkyl vinyl ether, polyvinyl fluoride, tetra Fluoroethylene / ethylene, tetrafluoroethylene / hexafluoropropylene, polychlorotrifluoroethylene, polyvinylidene fluoride, etc. It may be used las plastic film or sheet.

  In addition, the above plastic films or sheets, white films formed by adding white pigments and fillers to these synthetic resins, or sheets having microvoids inside the substrate, as well as condenser paper, glassine paper, sulfuric acid paper, synthetic paper (Polyolefin-based, polystyrene-based), fine paper, art paper, coated paper, cast coated paper, synthetic resin or emulsion-impregnated paper, synthetic rubber latex-impregnated paper, synthetic resin-added paper, cellulose fiber paper, and the like can also be used. Moreover, the laminated body which combined said sheet | seat etc. arbitrarily can also be used. Typical examples include a laminate of cellulose fiber paper and synthetic paper, and cellulose fiber paper and a plastic film.

  Moreover, the base material which carried out the easy adhesion process on the surface and / or back surface of said base material can also be used. The thickness of the substrate is usually about 3 μm to 300 μm, and preferably 100 μm to 250 μm in view of mechanical suitability and the like. Moreover, when the adhesiveness of a base material and the receiving layer provided on it is scarce, it is preferable that the surface has been subjected to easy adhesion treatment or corona discharge treatment.

<Dye-receiving layer>
The dye receiving layer 2 used in the thermal transfer image receiving sheet of the present invention will be described. The dye receptive layer used in the present invention is formed on the above-mentioned substrate, contains a metal ion-containing compound capable of reacting with a chelatable heat diffusible dye, and further has a dye receptivity. Containing a functional resin. Here, that the dye receiving layer contains a radiation curable resin means that the radiation curable resin described later is a main component, and includes the case where the radiation curable resin is cross-linked by radiation irradiation. .

(A) Metal ion-containing compound The metal ion-containing compound used in the receiving layer of the thermal transfer image-receiving sheet reacts with a heat-diffusible dye to form a heat-diffusible dye-metal ion-containing compound complex in the receiving layer.
Although it does not specifically limit as content in the receiving layer of the said metal ion containing compound, 5-80 mass% is preferable with respect to the binder resin mentioned later, and 10-70 mass% is more preferable.

The metal ion-containing compound used in the receiving layer of the thermal transfer image-receiving sheet is not particularly limited, and examples thereof include inorganic or organic salts of metal ions and metal complexes, among which salts of organic acids and Complexes are preferred. Examples of the metal include monovalent and polyvalent metals belonging to Groups I to VIII of the Periodic Table, among which Al, Co, Cr, Cu, Fe, Mg, Mn, Mo, Ni, Sn, Ti, and Zn is preferable, Ni, Cu, Cr, Co and Zn are more preferable, and Ni is particularly preferable. Specific examples of such metal ion-containing compounds include Ni ²⁺ , Cu ²⁺ , Cr ²⁺ , Co ^2+, and Zn ²⁺ and aliphatic salts such as acetic acid and stearic acid, benzoic acid, and salicylate. Examples thereof include salts of aromatic carboxylic acids such as acids. Moreover, the complex represented by the following general formula (1) can be particularly preferably used.

General formula (1) [M (Q ₁ ) ₁ (Q ₂ ) _m (Q ₃ ) _n ] ^{p +} (Y ⁻ ) ^p

In the above formulae, M represents a metal ion, preferably Ni ²⁺ , Cu ²⁺ , Cr ²⁺ , Co ²⁺ , or Zn ²⁺ . Q ₁ , Q ₂ , and Q ₃ each represent a coordination compound capable of coordination with a metal ion represented by M, and may be the same or different from each other. These coordination compounds can be selected from, for example, coordination compounds described in Chelate Science 5 (Keihei Ueno, Nanedo, 1975). Y represents an organic anion group, and specific examples include a tetraphenyl boron anion and an alkylbenzene sulfonate anion. l represents an integer of 1, 2 or 3, m represents 1, 2 or 0, and n represents 1 or 0. These are those in which the complex represented by the general formula (1) is bidentate-coordinated It is determined by tetradentate coordination or hexadentate coordination, or by the number of ligands of Q ₁ , Q ₂ and Q ₃ . P represents 0, 1 or 2. P = 0 indicates that the coordination compound represented by Q is an anionic compound, and the anionic compound represented by Q and the metal cation represented by M are electrically neutralized. means.

  As the anionic compound, a compound represented by the following general formula (2) is preferable.

In the formula, R ₁ and R ₃ may be the same or different and each represents an alkyl group or an aryl group, and R ₂ represents an alkyl group, an alkoxy group, a halogen atom, an alkoxycarbonyl group, or a hydrogen atom. R ₁ , R ₂ and R ₃ may be substituted with the same substituent as the substituent represented by R ₁₁ in the general formula (3) described later.

  In the present invention, the metal ion-containing compound is particularly preferably a compound represented by the following structural formula.

  In the present invention, the softening point of the dye receiving layer is preferably in the range of 50 ° C to 300 ° C, and more preferably in the range of 80 ° C to 250 ° C. This is because the dye receiving layer and the dye layer of the thermal transfer sheet can be prevented from being thermally fused. In addition, the said softening point is obtained from the result measured by a temperature rising rate; 3 degree-C / min with a rigid pendulum type surface physical property tester (RPT3000W by A & D), or the result is made into a graph.

  The radiation curable resin having dye acceptability is not particularly limited as long as it can accept dyes used in the sublimation thermal transfer system and can be cured by radiation such as ultraviolet rays or electron beams. Absent. Examples of such radiation curable resins include unsaturated polyesters, polyester (meth) acrylates, epoxy (meth) acrylates, urethane (meth) acrylates, polyol (meth) acrylates, melamine (meth) acrylates and the like (meta ) Acrylates and the like, and these may be used alone or in combination of two or more.

  In the present invention, among the above, the radiation curable resin is preferably an acrylic-modified polyvinyl butyral resin having a (meth) acryloyl group. This is because it is possible to increase the dye receptivity of the receiving layer. Examples of the acrylic-modified polyvinyl butyral resin having the (meth) acryloyl group include those represented by the following chemical formula.

(In the formula, R ¹ represents a hydrogen atom or an acetyl group, and R ² is a group having a (meth) acryloyl group. When the total of l, m, and n in the formula is 100, l 40 to 85, m is an integer of 15 to 50, and n is an integer of 0 to 15. The (meth) acryloyl group is bonded through an aromatic, aliphatic, or alicyclic linking group. In this case, the carbon number of R ² is usually in the range of 2 to 8.)

  Further, the above chemical formula is simply a formula for representing the quantitative ratio of each component of the resin, and does not specify the arrangement (for example, block structure or the like). In addition, the acrylic-modified polyvinyl butyral resin represented by the above general formula may contain a small amount of other constituents as long as the object of the present invention is not lost.

  The molecular weight of the acrylic-modified polyvinyl butyral resin having the (meth) acryloyl group is preferably in the range of 30,000 to 200,000, and more preferably in the range of 50,000 to 100,000.

  Here, the acrylic modified polyvinyl butyral resin having the (meth) acryloyl group is dissolved in a solvent capable of dissolving the polyvinyl butyral resin, for example, toluene, ketone, cellosolve acetate, dimethyl sulfoxide, etc. Can be produced by dropping and reacting (meth) acrylic acid having an isocyanate group or a derivative thereof with stirring. The isocyanate group reacts with the hydroxyl group of the polyvinyl butyral resin to form a urethane bond, and the (meth) acryloyl group is introduced into the resin through the urethane bond. At this time, the amount of the isocyanate group-containing (meth) acrylic acid compound used is 0.1 mol to 10 mol (preferably 0.5 to 3 mol) of isocyanate groups per mol of hydroxyl group based on the ratio of hydroxyl groups to isocyanate groups of the polyvinyl butyral resin. The amount is in the range.

  Examples of the isocyanate group-containing (meth) acrylic acid compound include those represented by the following general formula.

(In the formula, R ¹ represents a hydrogen group or a methyl group, and R ² represents an alkylene group having 1 to 5 carbon atoms (including those having an alkyl group in the side chain).)
Specific examples of the (meth) acrylic acid compound containing an isocyanate group represented by the above general formula include (meth) acryloyloxyisocyanate, (meth) acryloyloxyethylene isocyanate, (meth) acryloyloxypropylene isocyanate, (meth) Examples include acryloyloxyisopropylene isocyanate, (meth) acryloyloxybutylene isocyanate, and (meth) acryloyl isocyanate.

  As another method for producing the acrylic-modified polyvinyl butyral resin having the (meth) acryloyl group, a solvent capable of dissolving the polyvinyl butyral resin, such as toluene, ketone, cellosolve acetate, dimethyl sulfoxide, etc. While dissolving and stirring this solution, (meth) acrylic acid chloride or a derivative thereof can be dropped and reacted. In this case, the acid chloride group reacts with the hydroxyl group of the polyvinyl butyral resin to form an ester bond, and the residue of the (meth) acrylic acid compound is introduced into the resin through this ester bond. At this time, the amount of (meth) acrylic acid chloride or its derivative used is the ratio of hydroxyl group to acid chloride group of the polyvinyl butyral resin, and 0.1 mol to 5 mol (preferably 0.5 mol of acid chloride group per mol of hydroxyl group). ~ 3 mol).

  In the present invention, the softening point of the receptor layer is preferably in the range of 50 ° C to 300 ° C, and more preferably in the range of 80 ° C to 250 ° C. This is because the receiving layer and the dye layer of the thermal transfer ribbon can be prevented from being thermally fused. In addition, the said softening point is obtained from the result measured by a temperature rising rate; 3 degree-C / min with a rigid pendulum type surface physical property tester (RPT3000W by A & D), or the result is made into a graph. Specifically, as the measurement of viscoelasticity of the resin to be measured, the temperature at which the logarithmic decay rate becomes the peak value (maximum value) with respect to the temperature change is the softening point of the resin. In the graph shown in FIG. 3, the polyvinyl butyral resin used in Production Example 1 in the examples described later is used as a starting material, and the softening point of the polyvinyl butyral resin is about 120 ° C. In addition, an acrylic-modified polyvinyl butyral resin having a (meth) acryloyl group, which is a radiation-curable resin obtained by chemical reaction under the conditions shown in Production Example 1 described later, is indicated as UV-curable butyral in the graph. And the softening point of the coating film obtained is about 160 ° C. when the coating solution for forming the receiving layer shown in Example 1 is used except for the metal ion-containing material. It is a thing. Thus, by modifying the polyvinyl butyral resin as a starting material to make an acrylic-modified polyvinyl butyral resin having a (meth) acryloyl group, the softening point is improved, that is, the heat resistance is improved, and the thermal transfer sheet and It is possible to prevent heat fusion and abnormal transfer.

  In the formation of the receptor layer, the radiation curable resin described above is used as a main component. In the present invention, in addition to the radiation curable resin and the metal ion-containing compound, for example, the crosslinking density of the receptor layer is adjusted. For this purpose, a general thermoplastic resin, a reactive diluent such as an acrylic type, other monofunctional or polyfunctional monomer, oligomer, or the like may be used.

  For example, monofunctional (mono) methacrylates such as tetrahydrofurfuryl (meth) acrylate, hydroxyethyl (meth) acrylate, vinylpyrrolidone, (meth) acryloyloxyethyl succinate, (meth) acryloyloxyethyl phthalate, etc. may be mentioned. . For bifunctional and higher functional groups, polyol (meth) acrylate (epoxy-modified polyol (meth) acrylate, lactone-modified polyol (meth) acrylate, etc.), polyester (meth) acrylate, epoxy (meth) acrylate, urethane (meta) are classified by skeleton structure. ) Acrylate, other polybutadiene-based, isocyanuric acid-based, hydantoin-based, melamine-based, phosphoric acid-based, imide-based, phosphazene-based poly (meth) acrylates, and various monomers that are UV and electron beam curable , Oligomers and polymers.

  More specifically, bifunctional monomers and oligomers include polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, and the like. Examples of the trifunctional monomer, oligomer, and polymer include trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, and aliphatic tri (meth) acrylate. Examples of tetrafunctional monomers and oligomers include pentaerythritol tetra (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, and aliphatic tetra (meth) acrylate. Examples of pentafunctional monomers and oligomers include dipenta. In addition to erythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and the like, (meth) acrylate having a polyester skeleton, urethane skeleton, phosphazene skeleton, and the like can be given. The number of functional groups is not particularly limited, but if the number of functional groups is less than 3, the heat resistance of the receptor layer tends to decrease, and if it is 20 or more, the adhesion of the receptor layer to the substrate tends to decrease. In particular, it is preferable to use those having 3 to 20 functional groups.

  The reactive diluent is preferably used in an amount of 1 or less, particularly 0.05 to 0.5, when the amount of the radiation curable resin used in forming the receptor layer is 1. . Thereby, the crosslink density of the receiving layer formed can be increased, and the heat resistance of the receiving layer can be increased.

The receiving layer may contain a release agent. This makes it possible to prevent thermal fusion with the dye layer of the thermal transfer ribbon and decrease in print sensitivity during thermal transfer. Examples of the release agent used in the receiving layer include conventionally known release agents such as solid waxes such as polyethylene wax, amide wax, and Teflon (registered trademark), fluorine-based and phosphate-based surfactants, Silicone etc. are mentioned, These can be used 1 type or in mixture of 2 or more types. In the present invention, it is particularly preferable to use a modified silicone oil. Specifically, as the modified silicone oil, 1) a modified silicone oil side chain type,
2) Modified silicone oil both ends type,
3) Modified silicone oil one end type,
4) Modified silicone oil side chain both ends type,
5) Silicone graft acrylic resin, and 6) methylphenyl silicone oil.

  The modified silicone oil is classified into a reactive silicone oil and a non-reactive silicone oil. Examples of the reactive silicone oil include amino-modified, epoxy-modified, carboxyl-modified, carbinol-modified, methacryl-modified, mercapto-modified, phenol-modified, one-end-reactive, and different functional group-modified. Examples of the non-reactive silicone oil include polyether modified, methyl styryl modified, alkyl modified, higher fatty acid ester modified, hydrophilic special modified, higher alkoxy modified, higher fatty acid modified, and fluorine modified.

  Moreover, as addition amount of the said mold release agent, it is preferable to use 0.5-30 mass parts with respect to 100 mass parts of radiation-curable resin used for formation of a receiving layer. This is because if the range of the addition amount is not satisfied, there may be a problem that the receiving layer and the thermal transfer sheet are thermally fused or the printing sensitivity is lowered.

  Furthermore, in the present invention, when the radiation curable resin is cured by ultraviolet rays, it is necessary to add a photosensitizer when forming the receptor layer. In addition, when hardening the said radiation curable resin with an electron beam, a photosensitizer is unnecessary. Examples of the photosensitizer used in the present invention include various photosensitizers generally used as a photosensitizer for ultraviolet curable paints, such as benzoin, benzoin methyl ether, benzoin ethyl ether, and benzoin isopropyl. Benzoin compounds such as ether, α-methylbenzoin and α-phenylbenzoin; anthraquinone compounds such as anthraquinone and methylanthraquinone; benzyl: diacetyl; phenyl ketone compounds such as acetophenone and benzophenone; sulfides such as diphenyl disulfide and tetramethylthiuram sulfide Compound; α-chloromethylnaphthalene; anthracene, halogenated hydrocarbons such as hexachlorobutadiene and pentachlorobutadiene, and the like. Such a photosensitizer is preferably used in an amount of about 0.5 to 10 parts by mass per 100 parts by mass of the radiation curable resin.

  The receptor layer may contain a polymerization inhibitor such as phenols such as hydroquinone, t-butylhydroquinone, catechol, hydroquinone monomethyl ether; quinones such as benzoquinone and diphenylbenzoquinone; phenothiazines: copper. . Thereby, the storage stability of the composition for forming a receiving layer for forming the receiving layer can be improved. Furthermore, various adjuvants, such as a promoter, a viscosity modifier, surfactant, an antifoamer, and a silane coupling agent, may be contained as needed. Further, a polymer such as styrene / butadiene rubber may be contained.

  In addition, pigments and fillers such as titanium oxide, zinc oxide, kaolin, clay, calcium carbonate, fine powder silica are contained for the purpose of improving the whiteness of the receiving layer and further enhancing the sharpness of the printed image. May be. The receiving layer may contain known additives such as a plasticizer, an ultraviolet absorber, a light stabilizer, an antioxidant, a fluorescent brightener, and an antistatic agent.

In the present invention, as the method for forming the receptor layer, a solvent or a diluent is added to the composition obtained by adding the above-described radiation curable resin, the above-described metal ion-containing compound, and various additives as necessary. Etc. are added and kneaded sufficiently to prepare a composition for forming a receiving layer. Thereafter, on the above-mentioned substrate, for example, a gravure printing method, a screen printing method, a reverse roll coating method using a gravure plate, and the like, a method of forming by irradiating with radiation after drying. It can be. The coating amount of the receptor layer forming composition is preferably set to 0.5g / m ² ~4.0g / m ² in dry. This is because when the coating amount is less than 0.5 g / m ² at the time of drying, the dye receptivity is deteriorated, for example, unevenness occurs in fixing of the dye. In addition, when the coating amount is larger than the above amount, it is not preferable in terms of cost, and more drying time and curing time are required, and productivity is lowered.

  In the present invention, since a radiation curable resin is used for the dye receiving layer, it is possible to eliminate the need for, for example, a thermosetting step requiring a long processing time when forming the dye receiving layer. Therefore, the thermal transfer image receiving sheet can be manufactured efficiently. In the present invention, a resin that is cured by radiation is used for the dye-receiving layer, but “radiation” may be classified by quantum energy of electromagnetic waves, but in this specification, all ultraviolet rays (UV− A, UV-B, UV-C), visible light, gamma ray, X-ray, electron beam. Accordingly, ultraviolet (UV), visible light, gamma ray, X-ray, electron beam, or the like can be applied as ionizing radiation, but ultraviolet (UV) is preferable, and ultraviolet having a wavelength of 300 to 400 nm is optimal.

  In addition, the solvent used in the receiving layer forming composition is not particularly limited as long as it is an organic solvent in which the radiation curable resin as described above is dissolved, but the coating property and the drying property are not limited. In consideration, aromatic solvents such as toluene and xylene, ketone solvents such as acetone, methyl ethyl ketone (MEK), methyl isobutyl ketone, and cyclohexanone, and cellosolv organic solvents such as methyl cellosolve and ethyl cellosolve, particularly these solvents. A mixed solvent consisting of is preferably used. The solid content concentration of the radiation curable resin in the receiving layer forming composition is not particularly limited, but it is generally preferably in the range of 1% by mass to 50% by mass on a weight basis.

The thermal transfer image-receiving sheet of the present invention is not particularly limited as long as it has the above-mentioned base material and dye-receiving layer. If necessary, for example, charging between the base material and the receiving layer is performed. Layers such as a prevention layer, a cushion layer, an intermediate layer to which a white pigment and a fluorescent whitening agent are added, and an easy adhesion layer may be formed. In addition, a back layer may be formed on the surface of the substrate opposite to the surface on which the receiving layer is formed in order to improve the transportability of the thermal transfer image receiving sheet and to prevent curling. Examples of the back layer having such a function include an acrylic resin, a cellulose resin, a polycarbonate resin, a polyvinyl acetal resin, a polyvinyl alcohol resin, a polyamide resin, a polystyrene resin, a polyester resin, and a halogenated polymer. As an additive, an acrylic filler, polyamide filler, fluorine filler, organic filler such as polyethylene wax, amino acid powder, or a layer added with inorganic filler such as silicon dioxide or metal oxide can be used. Moreover, what hardened | cured the said resin with hardening | curing agents, such as an isocyanate compound, can also be used as a back surface layer. In addition, such a back layer can be formed by a method similar to the method for forming the receiving layer described above, using the composition for forming the back layer. Incidentally, the coating amount of the back surface layer forming composition is preferably set to an amount to be 0.5g / m ² ~5.0g / m ² approximately when dry. In the present invention, a layer such as an antistatic layer may be formed on the back layer.

  Next, each configuration of the thermal transfer sheet used in combination with the thermal transfer image receiving sheet of the present invention will be described in detail.

(Base material)
The base material used for the thermal transfer sheet will be described. The substrate used for the thermal transfer sheet is not particularly limited as long as it can form a dye layer and has predetermined heat resistance and strength. Examples of such a substrate include, for example, a polyethylene terephthalate film, a 1,4-polycyclohexylenedimethylene terephthalate film, a polyethylene naphthalate film, and a polyphenylene sulfide having a thickness of about 0.5 to 50 μm, preferably about 1 to 10 μm. Film, polystyrene film, polypropylene film, polysulfone film, aramid film, polycarbonate film, polyvinyl alcohol film, cellophane, cellulose derivatives such as cellulose acetate, polyethylene film, polyvinyl chloride film, nylon film, polyimide film, ionomer film, etc. are used. .

(Dye layer)
The thermal transfer sheet used for forming an image on the receiving layer of the thermal transfer image-receiving sheet has a structure in which a dye layer is provided on a substrate. In the present invention, the dye layer is a chelating heat-diffusible dye. Containing a binder resin and the heat diffusible dye as main components. First, the binder resin of the dye layer is not particularly limited as long as the dye is not easily diffused by heat and does not cause problems such as bleeding of the dye during storage or thermal fusion with the image receiving sheet during thermal transfer. Not known, but known ones can be used. Specifically, acrylic resins and derivatives thereof, polystyrene, polycarbonate, polysulfone, polyethersulfone, polyimide, polyvinyl acetal, polyvinyl butyral, polyester resin, polyurethane resin, vinyl chloride vinyl acetate copolymer resin, nitrocellulose, ethyl cellulose, acetic acid Examples thereof include cellulose such as cellulose and derivatives thereof.

  The heat diffusible dye is not particularly limited as long as it can chelate with the metal ion-containing compound contained in the receiving layer of the thermal transfer image-receiving sheet. General yellow dye, magenta dye, cyan dye Etc. can be used. Especially, it is preferable that it is a heat diffusible dye represented by the following general formula (3)-(8), (10), (11).

  (A) Thermally diffusible dye represented by the general formula (3)

(Wherein R ₁₁ represents a substituent, R ₁₂ represents an alkyl group, an alkenyl group, an alkynyl group or a cycloalkyl group, R ₁₃ and R ₁₄ represent a hydrogen atom or a substituent, and R ₁₅ , R ₁₆ , R ₁₇ and R ₁₈ represent a hydrogen atom, an alkyl group, or an aryl group, and Z ₁₁ represents a nonmetallic atom group necessary for forming a 5- or 6-membered nitrogen-containing heterocyclic ring.

The substituent represented by R ₁₁ is not particularly limited, and examples thereof include alkyl groups, cycloalkyl groups, aryl groups, acylamino groups, alkylthio groups, arylthio groups, alkenyl groups, halogen atoms, alkynyl groups, and heterocyclic groups. Arylsulfonyl group, alkylsulfinyl group, arylsulfinyl group, phosphono group, acyl group, carbamoyl group, sulfamoyl group, sulfonamido group, cyano group, alkoxy group, aryloxy group, heterocyclic oxy group, siloxy group, acyloxy group, Sulfonic acid group, sulfonic acid salt, aminocarbonyloxy group, amino group, anilino group, imide group, ureido group, alkoxycarbonylamino group, alkoxycarbonyl group, aryloxycarbonyl group, heterocyclic thio group, thioureido group, carboxyl group ,carboxylic acid Salt, a hydroxyl group, a mercapto group, and each group and a nitro group.

  These substituents may be further substituted with the same substituent.

The alkyl group, alkenyl group, alkynyl group or cycloalkyl group represented by R ₁₂ may be substituted with the same substituent as the substituent represented by R ₁₁ .

In the general formula (3), R ₁₃ and R ₁₄ represents a hydrogen atom or a substituent. Examples of the substituent represented by R ₁₃ and R ₁₄ include the same groups as the substituent represented by R ₁₁ , and these substituents may be further substituted with the same substituent.

In the general formula (3), R ₁₅ , R ₁₆ , R ₁₇ and R ₁₈ represent a hydrogen atom, an alkyl group or an aryl group. Examples of the alkyl group and aryl group represented by R ₁₅ , R ₁₆ , R ₁₇ and R ₁₈ include the same groups as the alkyl group and aryl group in R ₁₁ .

The alkyl group and aryl group represented by R ₁₅ , R ₁₆ , R ₁₇ and R ₁₈ may be substituted with the same substituent as the substituent represented by R ₁₁ .

In the general formula (3), Z ₁₁ represents a nonmetallic atom group necessary for forming a 5- or 6-membered nitrogen-containing heterocyclic ring.

Specific examples of such a heterocyclic ring include pyridine ring, pyrazole ring, imidazole ring, pyrazine ring, pyrimidine ring, triazine ring, thiazole ring, oxazole ring, quinoline ring, benzothiazole ring, benzoxazole ring and the like. be able to. These rings may have a substituent, and examples of the substituent include the same groups as the substituent represented by R ₁₁ .

  (B) Thermally diffusible dye represented by the general formula (4)

(Wherein R ₂₁ represents a trifluoromethyl group, an alkyl group, an aryl group, an alkoxy group, an alkoxycarbonyl group, an acyl group, an acyloxy group, an amide group, a carbamoyl group, an amino group, or a cyano group, and R ₂₂ represents represents an alkyl group, an acyl group, a carbamoyl group, an alkoxycarbonyl group, R ₂₃ represents an alkyl group, an alkenyl group, an aryl group. However, the total number of carbon atoms contained in R ₂₁ and R ₂₂ is 3 or more .X ₂₁ Represents —CR ₂₄ R ₂₅ —, —S—, —O—, —NR ₂₆ —, wherein R ₂₄ and R _{25 each} represent a hydrogen atom, a halogen atom or a substituent, and R ₂₆ represents a hydrogen atom or a substituted group. Y ₂₁ represents a group of atoms necessary to form a 5- to 6-membered ring.
Since the substituent is the same as the substituent in the general formula (I) described above, description thereof is omitted here.

In the general formula (4), R ₂₁ represents a trifluoromethyl group, an alkyl group, an aryl group, an alkoxy group, an alkoxycarbonyl group, an acyl group, an acyloxy group, an amide group, a carbamoyl group, an amino group, or a cyano group.
R ₂₁ is preferably an alkyl group, a trifluoromethyl group, an alkoxycarbonyl group, an acyl group, a carbamoyl group, or a cyano group, and more preferably an alkyl group.

R ₂₂ represents an alkyl group, an acyl group, a carbamoyl group, or an alkoxycarbonyl group.

R ₂₃ represents an alkyl group, an alkenyl group, or an aryl group.

X ₂₁ represents —CR ₂₄ R ₂₅ —, —S—, —O—, —NR ₂₆ —, and preferably —CR ₂₄ R ₂₅ —, —S—, —O—.

R ₂₄ and R ₂₅ represent a hydrogen atom, a halogen atom, or a substituent.
Since the substituent is the same as the substituent in the general formula (I) described above, description thereof is omitted here.

  As the substituent, a hydrogen atom, an alkyl group, and an aryl group are preferable.

R ₂₆ represents a hydrogen atom or a substituent.
Examples of the substituent include the same substituents as those exemplified as R ₂₄ and R ₂₅ .

Y ₂₁ represents an atomic group necessary for forming a 5- to 6-membered ring. Preferably, it is an atomic group necessary for forming a 6-membered ring. For example, a cyclopentane ring, a cyclohexane ring, a benzene ring, a pyridine ring, a naphthalene ring, etc. are mentioned.

  (C) Thermally diffusible dye represented by the general formula (5)

In the general formula (5), 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 connected 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.

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 a condensed ring 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 .

  The heat diffusible dyes represented by the above general formulas (3) to (5) are yellow dyes.

  (D) Thermally diffusible dye represented by the general formula (6)

(In the formula, Y ₃₁ represents an alkyl group, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, a carbamoyl group, an alkylsulfonyl group, an arylsulfonyl group, a sulfamoyl group, a cyano group, or a perfluoroalkyl group. Z ₃₁ , Z ₃₂ represents —CR ₃₂ ═ or —N═, L ₃₁ represents a group represented by the following general formula (6-a), X ₃₁ represents an unsubstituted or substituted alkylamino group, R ₃₁ Represents a substituted or unsubstituted alkyl group, n represents an integer of 0 or more, and R ₃₂ represents a hydrogen atom or a substituent.)

（式中、Ｂ₃₁は複素環を形成するのに必要な非金属原子群を表す。）

(In the formula, B ₃₁ represents a nonmetallic atom group necessary for forming a heterocyclic ring.)

L ₃₁ represents a group represented by the general formula (6-a) and includes a nonmetallic atom group B ₃₁ necessary for forming a heterocyclic ring. Examples of the group represented by the general formula (6-a) include 2-pyrrolyl group, imidazolyl group, isothiazolyl group, isoxazolyl group, 3-pyrazolyl group, pyrazinyl group, triazolyl group, 2-pyridyl group, pyridazinyl group, and pyrimidinyl group. It represents a 3H-indolyl group, a 1H-indazolyl group, a prynyl group, an isoquinolyl group, a quinolyl group, a phthalazinyl group, a naphthyridinyl group, a quinosalinyl group, a quinazolinyl group, or the like. These heterocyclic rings may further have a substituent. Examples of the substituent include a halogen atom, an alkyl group, an aryl group, an acyl group, an alkoxy group, an alkoxycarbonyl group, an acyloxy group, an alkylthio group, an arylthio group, An amino group, a cyano group, a nitro group, and a heterocyclic group are mentioned.

X ₃₁ represents an unsubstituted or substituted alkylamino group, and examples of the substituent include an aryl group, an acyl group, an alkoxy group, an alkoxycarbonyl group, an acyloxy group, an alkylthio group, an arylthio group, an amino group, a cyano group, and a nitro group. , Hydroxyl group, carboxyl group, sulfonic acid group, sulfonamide group, acylamino group, carbamoyl group, sulfamoyl group.

R ₃₁ represents a substituted or unsubstituted alkyl group. R ₃₂ represents a hydrogen atom or a substituent, and examples of the substituent include an alkyl group, an aryl group, an acyl group, an alkoxy group, an alkoxycarbonyl group, an acyloxy group, an alkylthio group, an arylthio group, an amino group, a cyano group, and a nitro group. Can be mentioned.

  (E) Thermally diffusible dye represented by the general formula (7)

(In the formula, Y ₄₁ represents the same substituent as Y ₃₁ described above, Z ₄₁ and Z ₄₂ represent —CR ₄₃ ═ or —N═, and L ₄₁ represents the general formula (7-a), (7— b) represents a group represented by X), X ₄₁ represents an unsubstituted or substituted alkylamino group, R ₄₁ represents a substituted or unsubstituted alkyl group, R ₄₃ represents a hydrogen atom or a substituent, n represents an integer of 0 or more.)

(Wherein R ₄₂ represents a hydroxyl group, an alkoxy group, an aryloxy group, an amino group, a mercapto group, an alkylthio group or an arylthio group, R _b represents a substituent, p represents an integer of 0 to 4, and B represents -CR ₄₂ = together represents a non-metallic atomic group necessary for forming a heterocyclic ring.)

L ₄₁ represents a group represented by general formula (7-a) or (7-b), and represents a group that forms a heterocyclic ring with —CR ₄₂ ═ and B ₄₁ represented by general formula (7-a). Is a pyrrolyl group, imidazolyl group, isothiazolyl group, isoxazolyl group, pyrazolyl group, pyrazinyl group, triazolyl group, pyridyl group, pyridazinyl group, pyrimidinyl group, 3H-inddolyl group, 1H-indazolyl group, purinyl group, isoquinolyl group, quinolyl group Group, phthalazinyl group, naphthyridinyl group, quinosalinyl group, quinazolinyl group and the like. _R42 represents a hydroxyl group, an alkoxy group (for example, methoxy, ethoxy, butoxy, etc.), an aryloxy group, an amino group, a mercapto group, an alkylthio group, or an arylthio group. These heterocyclic rings may further have a substituent. Examples of the substituent include a halogen atom, an alkyl group, an aryl group, an acyl group, an alkoxy group, an aryloxy group, an alkoxycarbonyl group, an acyloxy group, an alkylthio group, An arylthio group, an amino group, a cyano group, a nitro group, and a heterocyclic group are mentioned.

X ₄₁ represents an unsubstituted or substituted alkylamino group, and examples of the substituent include an aryl group, an acyl group, an alkoxy group, an alkoxycarbonyl group, an acyloxy group, an alkylthio group, an arylthio group, an amino group, a cyano group, and a nitro group. , Hydroxyl group, carboxyl group, sulfonic acid group, sulfonamide group, acylamino group, carbamoyl group, sulfamoyl group.

R ₄₁ represents a substituted or unsubstituted alkyl group. R ₄₂ represents a hydrogen atom or a substituent, the alkyl group as a substituent, an aryl group, an acyl group, an alkoxy group, an aryloxy group, an alkoxycarbonyl group, an acyloxy group, an alkylthio group, an arylthio group, an amino group, a cyano group, A nitro group etc. are mentioned.

Examples of the substituent represented by R _b include a halogen atom, an alkyl group, an aryl group, an acyl group, an alkoxy group, an aryloxy group, an alkoxycarbonyl group, an acyloxy group, an alkylthio group, an arylthio group, an amino group, a cyano group, and a nitro group. Group, heterocyclic group and the like.

  (F) Thermally diffusible dye represented by the general formula (8)

In the general formula (8), X represents at least a bidentate chelatable 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 (9).

In the above general formula (9), Z ₂ represents an atomic group necessary for forming an aromatic nitrogen-containing heterocyclic ring substituted with a group containing at least one 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 (8), 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 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 (6), 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 heat diffusible dyes represented by the above general formulas (6) to (8) are magenta dyes.

  (G) Thermally diffusible dye represented by general formula (10)

(In the formula, R ₅₁ and R ₅₂ each represent a substituted or unsubstituted aliphatic group, R ₅₃ represents a substituent, n represents an integer of 0 to 4, and when n is 2 or more, R ₅₃ may be the same or different, and R ₅₅ and R ₅₆ each represents an alkyl group, provided that at least one of R ₅₅ and R ₅₆ represents a secondary alkyl group.

In the general formula (10), R ₅₁ and R ₅₂ represent a substituted or unsubstituted aliphatic group, and R ₅₁ and R ₅₂ 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. Examples of the group capable of substituting these alkyl groups include a linear or branched alkyl group, a cycloalkyl group, And alkenyl group, aryl group, heterocyclic group, halogen atom, cyano group, nitro group, hydroxy group, carbonyl group, oxycarbonyl group, carbamoyl group, alkoxy group, aryloxy group, heterocyclic oxy group, carbonyloxy group, urethane Group, sulfonyloxy group, amino group, sulfonylamino group, sulfamoylamino group, acylamino group, ureido group, sulfonyl group, sulfamoyl group, alkylthio group, arylthio group, and heterocyclic thio group.

  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.

It is also preferred that R ₅₁ and R _{52 form} a non-aromatic cyclic structure (eg, pyrrolidine ring, piperidine ring, morpholine ring, etc.).

R ₅₃ represents a substituent, and examples of the substituent include those of the above R ₅₁ and R ₅₂ . Among the above substituents, an alkyl group, a cycloalkyl group, an alkoxy group, and an acylamino group are preferable. n represents an integer of 0 to 4, and when n is 2 or more, the plurality of R ₅₃ may be the same or different.

R ₅₅ and R ₅₆ represents an alkyl group. At least one of R ₅₅ and R ₅₆ represents a secondary alkyl group. The secondary alkyl group of R ₅₆ 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. _R55 and _R56 may be the same or different.

  (H) Thermally diffusible dye represented by the general formula (11)

In the general formula (11), R ₁₁ and R ₁₂ each represents 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 group capable of substituting these alkyl groups include linear or branched alkyl groups, cycloalkyl groups, and alkenyl groups, aryl groups, heterocyclic groups, halogen atoms, cyano groups, nitro groups, hydroxy groups, carbonyl groups, Oxycarbonyl group, carbamoyl group, alkoxy group, aryloxy group, heterocyclic oxy group, carbonyloxy group, urethane group, sulfonyloxy group, amino group, sulfonylamino group, sulfamoylamino group, acylamino group, ureido group, sulfonyl Group, sulfamoyl group, alkylthio group, arylthio group, heterocyclic thio group and the like.

Examples of the cycloalkyl group and the alkenyl group are the same as the above substituents.

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, preferably a secondary or tertiary alkyl 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, preferably a secondary or tertiary alkyl group. The alkyl group for R ₁₅ 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 a particularly preferred substituent is a linear alkyl group having 3 or more carbon atoms. The alkyl group represented by 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.

  The heat diffusible dyes represented by the above general formulas (10) to (11) are cyan dyes.

  The thermal transfer sheet used in the present invention forms a heat-resistant slipping layer on the side opposite to the surface on which the dye layer of the substrate is formed, and can prevent adverse effects such as sticking and printing wrinkles due to the heat of the thermal head. . The resin for forming the heat-resistant slipping layer may be a conventionally known resin, such as polyvinyl butyral resin, polyvinyl acetoacetal resin, polyester resin, vinyl chloride-vinyl acetate copolymer, polyether resin, polybutadiene resin. , Styrene-butadiene copolymer, acrylic polyol, polyurethane acrylate, polyester acrylate, polyether acrylate, epoxy acrylate, urethane or epoxy prepolymer, nitrocellulose resin, cellulose nitrate resin, cellulose acetate propionate resin, cellulose acetate butyrate Rate resin, cellulose acetate hydrodiene phthalate resin, cellulose acetate resin, aromatic polyamide resin, polyimide resin, polyamideimide resin, polycarbonate Boneto resins, and chlorinated polyolefin resins.

  The slipperiness imparting agent added to or overcoating the heat resistant slipping layer made of these resins includes phosphate ester, silicone oil, graphite powder, silicone graft polymer, fluorine graft polymer, acrylic silicone graft polymer, acrylic siloxane, aryl Silicone polymers such as siloxane can be mentioned, and it is preferable to use a polyol, for example, a polyalcohol polymer compound, a polyisocyanate compound, and a phosphate ester compound. Further, it is more preferable to add a filler.

The heat resistant slipping layer is prepared by dissolving or dispersing the above-described resin, slipperiness-imparting agent, and filler in a suitable solvent on a base material to prepare a heat resistant slipping layer forming coating solution. Can be formed by coating with a forming means such as gravure printing, screen printing, reverse roll coating using a gravure plate, and drying. The coating amount of the heat-resistant slip layer is a solid, it is preferably a ^{0.1g / m 2 ~3.0g / m 2} .

  Printing on the thermal transfer image-receiving sheet of the present invention can be performed by a general sublimation thermal transfer printing apparatus using the above-described thermal transfer sheet.

  The present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, and the present invention has substantially the same configuration as the technical idea described in the claims of the present invention, and any device that exhibits the same function and effect is the present invention. It is included in the technical scope of the invention.

  Next, the present invention will be described more specifically with reference to examples and comparative examples. In addition, the part or% in an example is a mass reference | standard unless there is particular notice.

(Production Example 1)
A 4-neck flask equipped with a thermometer, a stirrer, a dropping funnel, and a condenser tube was charged with 2.5 g of polyvinyl butyral (trade name S-REC BM-1, manufactured by Sekisui Chemical Co., Ltd.), 97 g of methyl ethyl ketone (hereinafter also referred to as MEK), And 0.03 g of dibutyltin dilaurate were added, and the temperature was set to 50 ° C. and stirred.
To this, 1.07 g of methacryloyloxyisocyanate (trade name Karenz MOI, manufactured by Showa Denko KK) was added dropwise. After dropping, a heat reaction was performed at 50 ° C. to obtain acrylic-modified polyvinyl butyral-1. The reaction was completed by measuring the amount of isocyanate in the reaction solution by back titration analysis and confirming that 90% or more of the charged isocyanate had reacted.

(Production Example 2)
In the same manner as in Production Example 1, 2.5 g of polyvinyl butyral (trade name: S-REC BM-1 manufactured by Sekisui Chemical Co., Ltd.), MEK 97 g, and 0.68 g of triethylamine were charged in a reactor, and the temperature was stirred at 60 ° C. To this, 1.06 g of acrylic acid croid (manufactured by Tokyo Chemical Industry) was dropped, and after the dropwise addition, a heating reaction was performed at 60 ° C., and the triethylamine hydrochloride precipitated after the completion of the reaction was removed with a centrifuge, and acrylic modified polyvinyl butyral 2 was obtained.

(Production Example 3)
In the same manner as in Production Example 1, 2.5 g of polyvinyl butyral (trade name ESREC BM-1 manufactured by Sekisui Chemical Co., Ltd.) and 97 g of MEK were charged in a reactor, and the temperature was stirred at 50 ° C. 2.93 g of methacryloyl isocyanate (trade name MAI, manufactured by Nippon Paint Co., Ltd.) was added dropwise thereto, and after the dropwise addition, a heat reaction was performed at 50 ° C. to obtain acrylic modified polyvinyl butyral-3.

(Production Example 4)
In the same manner as in Production Example 1, 2.5 g of polyvinyl butyral (trade name: ESREC BL-SH Sekisui Chemical Co., Ltd.), MEK 97 g, and 0.03 g of dibutyltin dilaurate were charged in a reactor, and the temperature was stirred at 50 ° C. 0.65 g of the above-mentioned Karenz MOI was added dropwise thereto, and after the addition, a heat reaction was performed at 50 ° C. to obtain acrylic modified polyvinyl butyral-4.

<Example 1>
On a synthetic paper (thickness 150 μm), using a coating solution of the following composition, apply with a bar coater so that the dry coating amount is 4 g / m ^2, and dry in an oven at 120 ° C. for 2 minutes. After that, UV curing (UV irradiation device manufactured by Fusion UV Systems Japan, light source; H bulb, 500 mJ / cm ² ) was performed to form a receiving layer, and the thermal transfer image receiving sheet of the present invention was produced.
[Receptive layer forming coating solution]
Acrylic modified polyvinyl butyral-1 (according to production example 1 above) (based on solid content)
100 parts Photopolymerization initiator (trade name Irg. 184, manufactured by Ciba Specialty Chemicals) 10 parts Photocurable monomer (trade name, KAYARAD DPHA, manufactured by Nippon Kayaku Co., Ltd.)
30 parts Metal ion-containing compound represented by the following chemical formula 100 parts Acrylic modified silicone 3 parts (FS-730 manufactured by NOF Corporation)
Methyl ethyl ketone 200 parts Toluene 200 parts

<Example 2>
A receiving layer was formed in the same manner as in Example 1 except that the receiving layer-forming coating solution having the following composition was used to obtain the thermal transfer image-receiving sheet of the present invention.
[Receptive layer forming coating solution]
Acrylic modified polyvinyl butyral-2 (according to Production Example 2 above) (solid content basis)
100 parts photopolymerization initiator (trade name Irg. 184, manufactured by Ciba Specialty Chemicals)
10 parts photo-curable monomer (trade name KAYARAD DPHA manufactured by Nippon Kayaku Co., Ltd.)
30 parts Metal ion-containing compound used in Example 1 100 parts Acrylic modified silicone 3 parts (FS-730, manufactured by NOF Corporation)
Methyl ethyl ketone 200 parts Toluene 200 parts

<Example 3>
A receiving layer was formed in the same manner as in Example 1 except that the receiving layer-forming coating solution having the following composition was used to obtain the thermal transfer image-receiving sheet of the present invention.
[Receptive layer forming coating solution]
Acrylic modified polyvinyl butyral-3 (according to production example 3 above) (based on solid content)
100 parts photopolymerization initiator (trade name Irg. 184, manufactured by Ciba Specialty Chemicals)
10 parts photo-curable monomer (trade name KAYARAD DPHA manufactured by Nippon Kayaku Co., Ltd.)
30 parts Metal ion-containing compound used in Example 1 100 parts Acrylic modified silicone 3 parts (FS-730, manufactured by NOF Corporation)
Methyl ethyl ketone 200 parts Toluene 200 parts

<Example 4>
A receiving layer was formed in the same manner as in Example 1 except that the receiving layer-forming coating solution having the following composition was used to obtain the thermal transfer image-receiving sheet of the present invention.
[Receptive layer forming coating solution]
Acrylic-modified polyvinyl butyral-4 (according to production example 4 above) (based on solid content)
100 parts photopolymerization initiator (trade name Irg. 184, manufactured by Ciba Specialty Chemicals)
10 parts photo-curable monomer (trade name KAYARAD DPHA manufactured by Nippon Kayaku Co., Ltd.)
30 parts Metal ion-containing compound used in Example 1 100 parts Acrylic modified silicone 3 parts (FS-730, manufactured by NOF Corporation)
Methyl ethyl ketone 200 parts Toluene 200 parts

<Comparative Example 1>
A receiving layer was formed in the same manner as in Example 1 except that a receiving layer forming coating solution having the following composition was used, and a thermal transfer image receiving sheet of Comparative Example 1 was obtained.
[Receptive layer forming coating solution]
Polyvinyl butyral resin (trade name: S-REC BM-1 manufactured by Sekisui Chemical Co., Ltd.)
100 parts Metal ion-containing compound used in Example 1 80 parts Acrylic modified silicone 3 parts (FS-730, manufactured by NOF Corporation)
Methyl ethyl ketone 150 parts Toluene 150 parts

Thermal transfer sheets used in combination with the thermal transfer image receiving sheets of Examples 1 to 4 and Comparative Example 1 were prepared as follows.
On one surface of a base material of a polyethylene terephthalate (PET) film (thickness: 4.5 μm), a coating solution for forming a heat-resistant slipping layer having the following composition is applied by a gravure coating method to a dry coating amount of 1.0 g / The heat resistant slipping layer was formed by applying and drying to m ² .
[Coating fluid for forming heat resistant slipping layer]
Polyvinyl butyral resin (trade name: S-REC BM-1 manufactured by Sekisui Chemical Co., Ltd.)
13.6 parts polyisocyanate curing agent (trade name Takenate D218, Takeda Pharmaceutical Company Limited)
0.6 parts Phosphoric ester
0.8 part Methyl ethyl ketone 42.5 parts Toluene 42.5 parts

A yellow dye layer (Y), a magenta dye layer (M), and a cyan dye layer (C) are coated on the surface of the substrate opposite to the side on which the heat-resistant slip layer is formed, using a coating liquid having the following composition. ) Was applied and dried with a bar coater so that the dry coating amount was 0.6 g / m ^2, and the dye layer was repeatedly formed in the flow direction in the surface order (Y, M, C, Y, M, C,...) Thermal transfer sheets were prepared.

[Yellow dye layer forming coating solution]
Thermally diffusible dye represented by the following chemical formula 4 parts Polyvinyl butyral resin (trade name KS-5, manufactured by Sekisui Chemical Co., Ltd.) 3.5 parts Methyl ethyl ketone 50 parts Toluene 50 parts

[Magenta dye layer forming coating solution]
Thermally diffusible dye represented by the following chemical formula 4 parts Polyvinyl butyral resin (trade name KS-5, manufactured by Sekisui Chemical Co., Ltd.) 3.5 parts Methyl ethyl ketone 50 parts Toluene 50 parts

[Cyan dye layer forming coating solution]
Thermally diffusible dye represented by the following chemical formula 4 parts Polyvinyl butyral resin (trade name KS-5, manufactured by Sekisui Chemical Co., Ltd.) 3.5 parts Methyl ethyl ketone 50 parts Toluene 50 parts

(Evaluation)
The thermal transfer image-receiving sheets prepared in Examples 1 to 4 and Comparative Example 1 and the thermal transfer sheet were overlapped, and printing was performed from the back surface of the thermal transfer image-receiving sheet under the following conditions to form an image. For the thermal transfer image-receiving sheets of Examples and Comparative Examples, the following methods were used to measure the printing density, release property test, light resistance test, heat resistance test, moisture resistance test, and blocking resistance test according to the following conditions. went.

(Printing conditions)
(Y, M, C printing conditions)
-Thermal head-Heating element average resistance: 5300 (Ω)
・ Print density in the main scanning direction: 300 dpi
-Sub-scanning direction printing density: 300 dpi
Applied power: 0.10 (w / dot)
1 line cycle: 2 (msec.)
・ Printing start temperature: 25 (℃)
Gradation control method: Using a multi-pulse test printer that can vary the number of divided pulses having a pulse length obtained by equally dividing one line period into 256 within a line period, from 0 to 255. The duty ratio was fixed to 90%, and the gradation was fixed to 256 for printing.

(Print density)
An image was formed under the above conditions, and a value (OD) at which the optical reflection density was maximized was measured by an optical densitometer (spectrolino manufactured by Gretag Macbeth).

(Releasability test)
The following evaluation criteria were used to check whether there was no thermal fusion between the thermal transfer image-receiving sheet and the thermal transfer sheet when printed under the above conditions, or whether there was a problem when peeling by hand.
○: There is almost no resistance when peeling, and there is no problem caused by thermal fusion between the thermal transfer image receiving sheet and the thermal transfer sheet.
Δ: Resistance is felt when peeling.
X: Cannot be peeled off due to thermal fusion (abnormal transfer).

(Light resistance test)
The printed matter obtained under the above printing conditions was evaluated for light resistance using a xenon fade meter under the following conditions.
Conditions for light resistance evaluation / irradiation tester: Ci35 manufactured by Atlas
・ Light source: Xenon lamp ・ Filter: Inside = IR filter
Outside = soda lime glass / black panel temperature: 45 (° C)
Irradiation intensity: measured value at 1.2 (W / m ² ) -420 (nm) Irradiation energy: integrated value at 400 (kJ / m ² ) -420 (nm)

  Next, the change in optical reflection density before and after irradiation under the above light resistance conditions was measured with an optical densitometer (spectrolino manufactured by Gretag Macbeth Co., Ltd.). The residual rate was calculated, and light resistance was evaluated based on the following evaluation criteria based on the residual rate.

Residual rate (%) = (optical reflection density after irradiation / optical reflection density before irradiation) × 100
Evaluation criteria ○: Residual rate is 80% or more and light resistance is good.
Δ: Residual rate is 60% to 70%, and light resistance is slightly inferior.

(Heat resistance test)
The printed matter obtained under the above printing conditions was left in a 60 ° C. environment for one week, and then the state of the printed matter was observed. The criteria for the evaluation are as follows.
○: No defects such as bleeding are found in the print portion, which is good.
Δ: Some blur is observed in the print portion, and the heat resistance is slightly inferior.

(Moisture resistance test)
The printed matter obtained under the above printing conditions was left in an environment of 50 ° C. and 80% RH for 100 hours, and then the state of the printed matter was observed. The criteria for the evaluation are as follows.
○: No defects such as bleeding are found in the print portion, which is good.
(Triangle | delta): A blur is seen in a printing part and moisture resistance is inferior.

(Blocking resistance test)
About the printed matter obtained under the above-mentioned printing conditions, the printed matter of each experimental example is overlapped with the image-receiving surface on which the image is formed facing the back side of the other printed matter, and this is 150 μm thick. After being left in an oven at 60 ° C. for 48 hours under a load of 20 kg / cm ² while being sandwiched between synthetic papers (Yupo FPG # 150 manufactured by Oji Oil Chemical Co., Ltd.), the superimposed image receiving surface and back surface are peeled off. The anti-blocking property was examined according to the evaluation criteria.
○: Not blocking.
Δ: Partially blocking.

Table 1 shows the measurement results of the print density, the releasability test, the light resistance test, the heat resistance test, the humidity resistance test, and the blocking resistance test.

  As is clear from Table 1, the thermal transfer image-receiving sheet produced in the example has a print density (OD) of 2.0 or more and high when any of the thermal transfer image-receiving sheets of Examples 1 to 4 is used. A print with a concentration could be obtained. In addition, the thermal transfer image-receiving sheets produced in the examples gave good results in all evaluations of the releasability test, light resistance test, heat resistance test, moisture resistance test and blocking resistance test. On the other hand, the thermal transfer image-receiving sheet produced in the comparative example did not give good results in the releasability test, light resistance test, heat resistance test, moisture resistance test and blocking resistance test.

It is a schematic sectional drawing which shows an example of the thermal transfer image receiving sheet of this invention. It is explanatory drawing explaining the thermal transfer image receiving sheet of this invention. It is a graph of viscoelasticity measurement results of a polyvinyl butyral resin as a starting material and an acrylic-modified polyvinyl butyral resin having a (meth) acryloyl group obtained by chemically reacting the starting material, and the peak value of the logarithmic decay rate is the softening point. Is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base material 2 Dye receiving layer 3 Thermal transfer image receiving sheet 10 Base material 11 Thermal transfer sheet 12 Dye layer 13 Thermal head

Claims (3)

  A thermal transfer image-receiving sheet comprising a dye-receiving layer containing a metal ion-containing compound capable of reacting with a chelatable heat-diffusible dye on at least one surface of a substrate, wherein the radiation having dye-receptivity is provided in the dye-receiving layer A thermal transfer image-receiving sheet comprising a curable resin.   The thermal transfer image-receiving sheet according to claim 1, wherein the radiation curable resin is an acrylic-modified polyvinyl butyral resin having a (meth) acryloyl group. The thermal transfer image-receiving sheet according to claim 2, wherein the acrylic-modified polyvinyl butyral resin having a (meth) acryloyl group is a resin represented by the following chemical formula.

(In the formula, R ¹ represents a hydrogen atom or an acetyl group, and R ² is a group having a (meth) acryloyl group. When the total of l, m, and n in the formula is 100, l Is 40 to 85, m is an integer of 15 to 50, and n is an integer of 0 to 15.)

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