JPH09226258A - Thermal transfer image receiving sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to enhance the adhesive properties of a base material sheet to a receiving layer and to form a clear image by sequentially providing a barrier layer containing water soluble resin as a main component and the receiving layer containing a metal ion supply compound represented by a specific formula from the base material sheet side on the sheet. SOLUTION: A barrier layer containing a water soluble resin as a main component and a receiving layer containing a metal source represented by a formula M<2+> (X<1-> )m (2-n)Y<-> are provided from a base material sheet side on the sheet. In the formula, M<2+> is a bivalent transition metal ion, X is a coordination compound which makes it possible to form a complex by coordinate bonding to the ion M<2+> , l is an integer or 0 to 1, (m) is integer of 2 or 3, a plurality of the compounds X may be same or different from each other, Y<-> is a counter ion of the ion M<2+> , and (n) is an integer of 0, 1 or 2. The barrier layer contains a white pigment, thereby stopping the source by the barrier layer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal transfer image-receiving sheet, and more particularly to a thermal transfer image-receiving sheet which uses a metal ion-supplying compound in the receiving layer and has a high adhesiveness between the base sheet and the receiving layer to obtain a clear image. It is about the seat.

[0002]

2. Description of the Related Art Conventionally, as a method for forming an image in accordance with image information using a thermal printing means such as a thermal head or a laser, thermal transfer provided with a sublimable dye layer having a property of transferring by heating. A method has been proposed in which a sheet is used in combination with a thermal transfer image-receiving sheet and the dye is transferred onto the thermal transfer image-receiving sheet while controlling the sublimable dye to form a photographic image with gradation. According to this method, an image having continuous gradations can be obtained from a television signal by a simple process, and an apparatus used at that time is not complicated.
Further, in this method, since the dye is transferred by thermal energy, when the sensitivity is increased (the transfer time is shortened), the sensitivity is increased by making the dye thermally highly diffusive. To be achieved. However, these highly diffusible dyes have the disadvantages that the image density after transfer is lowered by re-diffusion during storage, or the dye is not sufficiently fixed and easily bleeds. In order to solve these problems, a method of adding a mordant to the image receiving element or reacting with a dye to accelerate fixing is proposed. Among these, by heating a thermal transfer material containing a chelating heat-diffusible dye (dye), a means for forming a chelate dye with a metal ion supplying compound in the image receiving element is disclosed in JP-A-59-78893. It is proposed in each publication of JP-A-60-2398.

[0003]

According to the above means,
Although the image density is prevented from being lowered and the fixing property of the dye is improved, there is a problem that the adhesion property to the base sheet is low because the metal ion supplying compound is added to the receiving layer. In addition, an intermediate layer for increasing the adhesion between the base sheet and the receiving layer, and a whitening layer to which a white pigment (titanium oxide etc.) is added in order to conceal glare and unevenness on the surface of the base sheet. When used between the base sheet and the receiving layer,
The migration of the metal ion-supplying compound to the intermediate layer or the white color imparting layer causes a decrease in the adhesiveness between the intermediate layer or the white color imparting layer and the base sheet. Therefore, an object of the present invention is to prevent a decrease in adhesiveness with a base material sheet, which is caused by the presence of a metal ion supplying compound (hereinafter referred to as a metal source) in a receiving layer, and to obtain a clear image by thermal transfer image reception. To provide a seat.

[0004]

[Means for Solving the Problems] In order to solve the above problems, as a result of intensive studies by the present inventors, a barrier layer containing a water-soluble resin as a main component on a base sheet and the following general formula ( It was found that the receiving layer containing the metal source represented by 1) was provided in order from the base material sheet side. General formula (1): M ²⁺ (X ¹⁻ ) _m (2-n) Y ⁻ However, in the formula, M ²⁺ represents a divalent transition metal ion. X
Represents a coordination compound capable of forming a complex by coordination-bonding to the transition metal ion M ²⁺ , 1 represents an integer of 0 or 1, and m represents an integer of 2 or 3. The plurality of coordination compounds X may be the same as or different from each other. Y ^-
Represents a counter ion of the transition metal ion M ²⁺ , n is 0, 1,
Or an integer of 2. Further, the barrier layer contains a white pigment. Furthermore, a white color imparting layer is provided on at least one of the upper and lower sides of the barrier layer.

The operation of the present invention is as follows. That is, the thermal transfer image-receiving sheet of the present invention, on the substrate sheet,
Adhesion to the base sheet is lowered by providing a barrier layer whose main component is a water-soluble resin and a receiving layer containing a metal source represented by the following general formula (1) in order from the base sheet side. The metal source to be used is clamped by the barrier layer, and the adhesiveness with the base sheet is not reduced,
A clear image can be obtained. General formula (1): M ²⁺ (X ¹⁻ ) _m (2-n) Y ⁻ However, in the formula, M ²⁺ represents a divalent transition metal ion. X
Represents a coordination compound capable of forming a complex by coordination-bonding to the transition metal ion M ²⁺ , 1 represents an integer of 0 or 1, and m represents an integer of 2 or 3. The plurality of coordination compounds X may be the same as or different from each other. Y ^-
Represents a counter ion of the transition metal ion M ²⁺ , n is 0, 1,
Or an integer of 2. In addition, since the barrier layer contains a white pigment, a glare and unevenness on the surface of the base material sheet are hidden, and a clearer image can be obtained. Further, by providing the white color imparting layer on at least one of the upper and lower sides of the barrier layer, a clear image having higher whiteness can be obtained.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Next, embodiments of the present invention will be described. The thermal transfer image-receiving sheet of the present invention has a structure in which a barrier layer is formed on one surface of a substrate sheet, and a receiving layer is further provided on the barrier layer. Also, a back surface layer can be provided on the other surface of the base material sheet.

(Base Material Sheet) The base material sheet has a role of holding the receptive layer, and since it is heated during thermal transfer, it has mechanical strength that does not hinder handling even in a heated state. Is preferred. The material of such a base sheet is not particularly limited, and examples thereof include condenser paper, glassine paper, sulfuric acid paper, or paper with a high degree of size, synthetic paper (polyolefin-based or 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, etc., 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, Liether sulfone, tetrafluoroethylene perfluoroalkyl vinyl ether, polyvinyl fluoride, tetrafluoroethylene ethylene, tetrafluoroethylene hexafluoropropylene, polychlorotrifluoroethylene, polyvinylidene fluoride and the like films, A white opaque film formed by adding a white pigment or a filler to these synthetic resins or a foamed foam sheet can also be used.
There is no particular limitation.

Further, a laminate made of any combination of the above-mentioned base sheets can also be used. As an example of a typical laminated body, there is a synthetic paper of cellulose fiber paper and synthetic paper or a synthetic paper of cellulose fiber paper and plastic film. The thickness of these substrate sheets may be arbitrary and is usually 10 to 3
It is about 00 μm. When the adhesion between the base sheet and the layer provided thereon is poor, it is preferable to subject the surface of the base sheet to various primer treatments or corona discharge treatments.

(Receiving Layer) The thermal transfer image-receiving sheet of the present invention comprises
On one surface of the base sheet, a receiving layer containing at least a compound represented by the following general formula (1) as a metal source is provided. Formula (1) M ²⁺ (X ¹⁻ ) _m (2-n) Y ⁻ However, in the formula, M ²⁺ represents a divalent transition metal ion. X
Represents a coordination compound capable of forming a complex by coordination-bonding to the transition metal ion M ²⁺ , 1 represents an integer of 0 or 1, and m represents an integer of 2 or 3. The plurality of coordination compounds X may be the same as or different from each other. Y ^-
Represents a counter ion of the transition metal ion M ²⁺ , n is 0, 1,
Or an integer of 2. Further, the compound represented by the general formula (1) may have a neutral ligand depending on the central metal, and typical ligands include H ₂ O, NH ₃ , pyridine and N-. Examples include methyl imidazole. In the compound represented by the general formula (1), M ²⁺ represents a divalent transition metal ion. Examples of this transition metal ion include Co ²⁺ , Ni ²⁺ , Cu ²⁺ , Zn ²⁺ , Fe ^{2+ and the} like. Among these, especially Ni ²⁺ , Cu
²⁺ and Zn ²⁺ are preferable. The addition amount of the metal source used in the present invention is preferably 0.5 to 20 g, and more preferably 1 to 15 g per 1 m ^{2 of the} solid content of the metal source transfer layer.

Further, it is preferable to add a release agent to the receptor layer in order to prevent heat fusion with the dye layer. As the release agent, a reaction-curable silicone, a phosphoric acid ester-based surfactant, a fluorine-based compound, or the like can be used. Among them, a reaction-curable silicone, specifically, a vinyl-modified silicone or an amino-modified silicone is used. A reaction cured product of silicone and epoxy-modified silicone is preferably used. The amount of the release agent added is 0.5 with respect to the solid content of the receiving layer.
-10 wt% is preferable. Further, as the receiving layer, a conventionally known metal source other than the general formula (1) can be used in combination.

The above-mentioned receiving layer is an ink prepared by adding additives such as a releasing agent to a binder resin and a metal source on a base material sheet, if necessary, and dissolving or dispersing them in water or a solvent such as an organic solvent. Can be applied by a usual method such as a bar coater, a gravure printing method, a screen printing method, and a reverse roll coating method using a gravure plate, and dried to form the composition. The barrier layer, the intermediate layer, and the back surface layer which will be described later are also formed by the same method as in the case of the above-mentioned receiving layer. Further, the receiving layer is formed not only by directly applying the ink on the base material sheet and drying as described above, but also by forming the receiving layer on another base material sheet in advance. The receiving layer may be transferred and formed on the material sheet. In addition, as the above-mentioned other base sheet, a material having the same conditions as the base sheet can be used. The thickness of the receiving layer is preferably 0.1 to 10 μm in terms of the film thickness after coating and drying.

(Barrier Layer) A barrier layer is provided between the receiving layer and the base sheet. The water-soluble resin that is the main component of the barrier layer is preferably a resin that adheres to both the base sheet and the receiving layer, ethylene-vinyl acetate copolymer, polyvinyl acetate, vinyl chloride-vinyl acetate copolymer, Emulsion adhesives such as vinyl acetate (meth) acrylic resin, styrene (meth) acrylic resin, styrene resin and other vinyl resins, or melamine resin, urea resin, polyamide resin such as benzoguanamine resin, etc. may be blended, and polyester resin , Polyurethane resin,
Resins similar to those used for the receiving layer such as vinyl chloride resin are also preferable. These water-soluble resins are completely dissolved (particle size of the resin is 0.01 μm or less) or colloidal dispersion (particle size is 0.01 μm) in a solvent mainly composed of water.
m or more than 0.1 μm), emulsion (particle size greater than 0.1 μm and less than 1 μm), or slurry (particle size greater than 1 μm), suitable for each resin It is used in a simple aqueous solution. Solvents such as alcohols and cellosolves may be added to the coating liquid for the barrier layer within the range of being compatible with each other, for stability of the solution, prevention of foaming and azeotropic effect.

It is also preferable that the water-soluble resin is polyvinyl alcohol and that it further contains a water-soluble resin other than polyvinyl alcohol. The water-soluble resin other than polyvinyl alcohol can be selected from polyester, polyurethane, vinyl chloride resin, vinyl acetate resin, styrene resin, styrene acrylic resin, and the like. The coating amount of the barrier layer is 0.5 in the dry state.
˜2.0 g / cm ² is preferred. If it is less than 0.5 g / cm ² , there is no effect of preventing the migration of the metal source to the base sheet, and if it exceeds 2.0 g / cm ² , the printing sensitivity is lowered. Furthermore, it is preferable to add a white pigment to the barrier layer in order to conceal the feeling of glare and unevenness on the surface of the base sheet, because the degree of freedom in selecting the base sheet is expanded.

As the white pigment, inorganic pigments such as titanium oxide, zinc oxide, barium sulfate and alumina white,
Examples include extender pigments such as polyethylene, carion clay, silica, magnesium carbonate and calcium carbonate. When titanium oxide is used as the white pigment, there are two types of titanium oxide: rutile type titanium oxide and anatase type titanium oxide.
Although there are various types, in consideration of the whiteness and the effect of the fluorescent brightening agent, anatase type titanium oxide, which absorbs ultraviolet rays on the shorter wavelength side, is preferable to rutile type titanium oxide. When titanium oxide is difficult to disperse in the resin aqueous solution, it can be dispersed by using titanium oxide whose surface is hydrophilically treated or by adding a known dispersant such as a surfactant or ethylene glycol. .

Further, in order to facilitate dispersibility, there is a method of preparing a titanium oxide paste in advance and dispersing it in a resin liquid. Titanium oxide paste refers to titanium oxide powder added with a known dispersant such as a surfactant or ethylene glycol in a single solvent such as water, alcohols, cellosolves, or a mixed solvent in an appropriate ratio. Dispersed in. As commercial products, Dispa Color White AEX, Dispa Color White Conc EX, Color Paste White N, Color Paste White Conc RN ((Ltd.)
Toupe) and the like. The content of the resin constituting the barrier layer and titanium oxide is preferably 30 to 300 parts by weight of titanium oxide solid content with respect to 100 parts by weight of resin solid content, but in the range of 100 to 300 parts by weight in order to enhance the hiding property. It is more preferable to use. In addition to the barrier layer described above, at least one intermediate layer may be provided between the receiving layer and the base sheet. The intermediate layer means all layers provided between the receiving layer and the base sheet, such as a white color imparting layer, an adhesive layer (primer layer), a UV (ultraviolet) absorbing layer, a foam layer, an antistatic layer, etc. Can be used as required.

(Back surface layer) A back surface layer may be provided on the back surface of the thermal transfer image-receiving sheet in order to improve the mechanical transportability of the sheet, prevent curling, and prevent static electricity. In order to improve the transportability, it is preferable to add an appropriate amount of organic or inorganic filler to the binder resin, or to use a resin having high lubricity such as polyolefin resin or cellulose resin. Further, in order to obtain an antistatic function, a layer made of a conductive resin such as an acrylic resin or a conductive filler, and further a fatty acid ester, a sulfuric acid ester, a phosphoric acid ester, an amide, a quaternary ammonium salt, a betaine , Various kinds of antistatic agents such as amino acids, ethylene oxide adducts and other ionic compounds may be added, or they may be provided as an antistatic agent on the back surface layer or between the back surface layer and the base sheet. The amount of the antistatic agent used varies depending on the layer to which the antistatic agent is added and the type of the antistatic agent, but in any case, the surface electric resistance value of the thermal transfer image-receiving sheet is preferably 10 ¹³ Ω / cm ² or less. . When the surface electric resistance value is larger than 10 ¹³ Ω / cm ² , the thermal transfer image receiving sheets stick to each other due to electrostatic contact, which causes a paper feeding trouble. Quantitatively, the amount used is preferably 0.01 to 3.0 g / m ² . If the amount of the antistatic agent used is less than 0.01 g / m ² , the antistatic effect is insufficient, while if it exceeds 3.0 g / m ² , it is too much and uneconomical. If it is provided on the surface, problems such as stickiness may occur.

The thermal transfer sheet used in combination with the thermal transfer image-receiving sheet of the present invention has a dye layer on one surface of the substrate and a back layer on the other surface of the substrate. (Substrate) As the substrate, the same substrate as that used in the conventional thermal transfer sheet can be used as it is, and is not particularly limited. Specific examples of preferable base materials include:
Thin paper such as glassine paper, condenser paper, paraffin paper,
Highly heat-resistant polyester such as polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polyphenylene sulfide, polyether ketone, polyether sulfone, polypropylene, polycarbonate, cellulose acetate, polyethylene derivatives, polyvinyl chloride, polyvinylidene chloride, polystyrene Examples include stretched or unstretched films of plastics such as polyamide, polyimide, polymethylpentene, and ionomer, and those obtained by laminating these materials. The thickness of this base material can be appropriately selected depending on the material so that the strength, thermal conductivity, heat resistance, etc. are appropriate, but normally a thickness of about 1 to 100 μm is preferably used. When the substrate as described above has poor adhesion to the dye layer formed on the surface thereof, it is preferable to subject the surface to primer treatment or corona discharge treatment.

(Back Layer) The binder resin used in the back layer is, for example, a cellulose resin such as ethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, methyl cellulose, cellulose acetate, cellulose acetate butyrate, nitrified cotton, polyvinyl alcohol, polyacetic acid. Vinyl-based resins such as vinyl, polyvinyl butyral, polyvinyl acetal, polyvinylpyrrolidone, etc., acrylic-based resins such as polymethyl methacrylate, polyethyl acrylate, polyacrylamide, acrylonitrile / styrene copolymer, polyamide resins, vinyltoluene resins, coumarone Examples thereof include indene resin, polyester resin, polyurethane resin, silicone-modified urethane resin, and fluorine-modified urethane resin.

Further, these resins may be mixed and used. In order to further improve the heat resistance of the back layer, a resin having a reactive group such as a hydroxyl group may be used among the above resins, and polyisocyanate or the like may be used as a crosslinking agent to form a crosslinked resin layer. Further, in order to improve slipperiness with a heating device such as a thermal head, a solid or liquid mold release agent or lubricant may be added to the back surface layer so as to have heat resistant slipperiness. Examples of the releasing agent or lubricant include various waxes such as polyethylene wax and paraffin wax, higher aliphatic alcohol, oreganopolysiloxane, anionic surfactant, cationic surfactant, amphoteric surfactant, nonionic surfactant. Activators, fluorine-based surfactants, organic carboxylic acids and their derivatives, fluorine-based resins, silicone-based resins, fine particles of inorganic compounds such as talc and silica can be used. The preferable amount of the lubricant added to the back layer is 5 to 50% by weight based on the total solid content of the back layer, and particularly preferably 10 to 3%.
0% by weight. The back layer can be formed in the same manner as the above-mentioned receiving layer, and its thickness is, after coating and drying,
It is preferably about 0.1 to 10 μm.

(Dye layer) The dye layer is mainly composed of a chelatable heat transferable dye and a binder resin. The heat transferable dye is not particularly limited as long as it has a group capable of forming a complex with the above-mentioned polyvalent metal ion, but the dye compound represented by the following general formula (2) or (3) Is preferred. General formula (2)

Embedded image (However, in the general formula (2), X ₁ represents a group of atoms necessary for completing an aromatic carbocycle or heterocycle in which at least one ring is composed of 5 to 7 atoms, And at least one of the adjacent carbon atoms bonded to the azo bond is (A) a carbon atom, (B) a nitrogen atom, an oxygen atom or a sulfur atom, and X ₂ has at least one ring composed of 5 to 7 atoms. Represents a group of atoms necessary to complete the aromatic carbocycle or heterocycle, and G represents a chelating group.)

General formula (3)

Embedded image (However, in the general formula (3), X ₁ has the same meaning as defined in the general formula (2), Z ₁ represents an electron-withdrawing group, and Z ₂
Represents an aryl group. ) Specific examples of the heat transferable dyes represented by the general formulas (2) and (3) include, for example, JP-A-59-7889.
No. 3, No. 59-109394 and No. 60-2398 can be cited. Further, it can be produced according to the synthesis methods disclosed in these publications.

The yellow dye is preferably represented by the following general formula (4). General formula (4)

Embedded image In the formula, R ₁₁ and R ₁₂ each represent a hydrogen atom or a substituent, Y ₁ represents OR ₁₃ , SR ₁₃ or NR ₁₃ R ₁₄ ,
Z ₁₁ represents an atomic group necessary for constituting a 5- or 6-membered aromatic ring together with 2 carbon atoms. R ₁₃ and R ₁₄ are each
It represents an alkyl group or an aryl group which may have a substituent.

The substituent represented by R ₁₁ and R ₁₂ is, for example, a halogen atom (fluorine, chlorine, etc.), an alkyl group (methyl, i-propyl, t-butyl, trifluoromethyl, methoxymethyl, 2-methyl). Sulfonylethyl, 2-methanesulfonamidoethyl, etc.), cycloalkyl group (cyclopentyl, cyclohexyl, etc.), aryl group (phenyl, 3-methylphenyl, 4-t-butylphenyl, 2-methoxyphenyl, 3-acetaminophenyl, etc.) ), A cyano group, an acyl group, an alkoxy group, an aryloxy group, an acylamino group, an anilino group,
Ureido group, sulfamoylamino group, alkylthio group, arylthio group, alkoxycarbonylamino group,
Sulfonamide group, carbamoyl group, sulfamoyl group, sulfonyl group, alkoxycarbonyl group, heterocyclic oxy group, heterocyclic thio group, acyloxy group, carbamoyloxy group, silyloxy group, aryloxycarbonylamino group, imide group, phosphonyl group, etc. can give.
Examples of the alkyl group and aryl group represented by R ₁₃ and R ₁₄ are the same as the alkyl group and aryl group represented by R ₁₁ and R ₁₂ .

5-6 composed of Z ₁₁ and two carbon atoms
Examples of the aromatic ring of the member include rings such as benzene, pyridine, pyrimidine, triazine, pyrazine, pyridazine, pyrrole, furan, thiophene, pyrazole, imidazole, triazole, oxazole, and thiazole. A condensed ring may be formed with the group ring.

As the magenta dye, the following general formula (5) is preferable. General formula (5)

Embedded image In the formula, R ₂₁ represents an alkyl group, a halogen atom or a hydrogen atom, R ₂₂ represents an alkyl group or a hydrogen atom, and R ₂₃
And R ₂₄ are each an alkyl group which may have a substituent,
It represents an aralkyl group which may have a substituent or an aryl group which may have a substituent. However, at least one of R ₂₃ and R ₂₄ is an alkyl-substituted aryl group or an alkyl-substituted aralkyl group. Examples of the halogen atom represented by R ₂₁ include chlorine and bromine, and examples of the alkyl group represented by R ₂₁ and R ₂₂ include methyl, ethyl and butyl. Examples of the alkyl group, aralkyl group and aryl group which may be substituted, represented by R ₂₃ and R ₂₄ include methyl, ethyl, propyl, i-propyl, butyl, sec-butyl, pentyl, hexyl and methoxyethyl. , Ethoxycarbonylmethyl, benzyl,
Examples include phenethyl, 4-methylbenzyl, phenyl, m-tolyl, p-tolyl and the like. However, at least one of R ₂₃ and R ₂₄ is an alkyl-substituted aryl group (m-
Or trialkyl, 4-methoxyphenyl, etc.) or an alkyl-substituted aralkyl group (methylbenzyl).

As the cyan dye, the following general formula (6) is preferable. General formula (6)

[Chemical 6] In the formula, R ₃₁ represents a group of atoms necessary for forming a substituted or unsubstituted aromatic ring, and Z ₃₂ is necessary for forming a substituted or unsubstituted thiazole ring, benzothiazole ring or pyridine ring, respectively. R ₃₁ represents an optionally substituted alkyl group, and R ₃₁ represents an optionally substituted alkyl group. The aromatic ring formed by R ₃₁ is preferably a benzene ring or a naphthalene ring. R ₃₁
The optionally substituted alkyl group represented by is preferably a linear or branched alkyl group having 1 to 12 carbon atoms,
For example, methyl, ethyl, propyl, iso-propyl,
Butyl, t-butyl, hexyl, 2-ethylhexyl,
Decyl, methoxyethyl, chloromethyl, 2-carboxyethyl, benzyl and the like can be mentioned. Examples of typical compounds of the dyes represented by the general formulas (4), (5) and (6) are shown below, but the dyes are not limited to these.

Examples of yellow dyes include Y-1 to Y-5.

Embedded image Examples of magenta dyes include M-1 to M-5.

Embedded image Examples of cyan dyes include C-1 to C-5.

Embedded image The chelating heat transferable dye used in the present invention is usually added in an amount of 0.1 g to 1 m ^{2 of the} solid content of the dye layer.
20 g is preferable, and 0.2 g to 5 g is more preferable.

The binder resin used in the dye layer is a water-soluble polymer such as cellulose-based, polyacrylic acid-based, polyvinyl alcohol-based, polyvinylpyrrolidone-based, acrylic resin, methacrylic resin, polystyrene, polycarbonate, polysulfone, polyether sulfone, polyvinyl. There are polymers soluble in organic solvents such as butyral, polyvinyl acetal, ethyl cellulose, and nitrocellulose. When using a polymer soluble in an organic solvent,
Not only one kind or two or more kinds dissolved in an organic solvent may be used, but it may be used in the form of latex dispersion. Further, a releasing agent may be added or a releasing layer may be provided in order to improve the releasing property from the receiving layer. As the release agent, a reaction-curable silicone, a phosphate ester-based surfactant, a fluorine compound or the like can be used. The amount of the binder resin used is preferably 0.1 g to 50 g per 1 m ² of the base material.

As a heat source for giving heat energy, a known one such as a laser beam, an infrared flash lamp, and a heating pen can be used in addition to the thermal head. As a method of applying thermal energy, in addition to the thermal transfer sheet side, it may be performed from the thermal transfer image receiving sheet side or from both sides. From the viewpoint of effective utilization of thermal energy, the thermal energy is applied from the thermal transfer sheet side. It is preferable to give. However, when the thermal energy is applied from the thermal transfer image receiving sheet, the thermal energy applied is controlled to express the gradation of the density of the image, or the dye is promoted to diffuse on the thermal transfer image receiving sheet, and the continuous image of the image is transferred. This is preferable in the sense that the key expression is made more reliable, and the heat energy can be changed continuously or in multiple steps from both sides. When a thermal head is used as a heat source for applying heat energy, the applied heat energy can be changed continuously or in multiple steps by modulating the voltage or pulse width applied to the thermal head.
When laser light is used as a heat source for giving heat energy, the heat energy to be given can be changed by changing the light amount or irradiation area of the laser light.
Further, if a dot generator with a built-in acousto-optic element is used, it is possible to give heat energy according to the size of the halftone dot.

When a laser beam is used, it is advisable to bring the thermal transfer sheet and the thermal transfer image-receiving sheet into close contact with each other. Further, for improving the absorption of the laser beam on the surface irradiated with the laser beam, for example, It is good to color it black. Alternatively, if a substance that absorbs non-sublimable laser light and converts it into heat is added to the dye layer, heat transfer to the dye is further performed and the resolution of the image is increased. When an infrared flash lamp is used as a heat source for giving heat energy, it may be carried out in the same manner as in the case of using a laser beam, or through a pattern or a halftone dot pattern in which the shade of an image such as black is continuously expressed. Alternatively, a black dye layer on one surface may be combined with a negative pattern corresponding to the negative of the above pattern.

[0031]

[Examples] Specific examples will be described below. Example 1 A synthetic paper having a thickness of 150 μm (trade name: YUPO FPG # 150, manufactured by Oji Yuka Co., Ltd.) was used as a base sheet, and one surface of the base sheet had a barrier layer coating solution 1 having the following composition. , and the receptor layer coating liquid 1 applied amount after drying was coated from the substrate sheet side in order to respectively the ^{1g / m 2, 4g / m} 2, dried for 2 minutes at 130 ° C. for each layer,
A thermal transfer image receiving sheet was prepared. Furthermore, a 6 μm-thick polyethylene terephthalate film (trade name: Lumirror, manufactured by Toray Industries, Inc.) having a heat-resistant back layer provided on one surface was coated with a dye layer coating solution having the following composition at a dry amount of 1 on the other surface. ．
A thermal transfer sheet was prepared by applying ² g / m2.

[Composition of Barrier Layer Coating Liquid 1] Polyurethane resin 100 parts by weight (Toyobo Co., Ltd. Bayronal GX-W-27) Water 50 parts by weight Isopropyl alcohol 50 parts by weight

[Receptor Layer Coating Liquid 1 Composition] Vinyl chloride-vinyl acetate copolymer resin 100 parts by weight (# 1000GK manufactured by Denki Kagaku Kogyo Co., Ltd.) Metal source (the following chemical formula 7) 20 parts by weight Epoxy modified silicone 1 part by weight (Shin-Etsu Chemical Co., Ltd. KF-393) Amino-modified silicone 1 part by weight (Shin-Etsu Chemical Co., Ltd. KS-343) Methyl ethyl ketone 240 parts by weight Toluene 240 parts by weight

[0034]

Embedded image

[Composition of Dye Layer Coating Liquid] <Yellow Dye Layer> Chelate Dye (Exemplified Compound Y-1) 4 parts by weight Polyvinyl butyral resin 70 parts by weight Methyl ethyl ketone 13 parts by weight Toluene 13 parts by weight <Magenta dye layer> Chelate dye (Exemplified compound M-1) 4 parts by weight Polyvinyl butyral resin 70 parts by weight Methyl ethyl ketone 13 parts by weight Toluene 13 parts by weight <Cyan dye layer> Chelate dye (Exemplary compound C-1) 4 parts by weight Polyvinyl butyral resin 70 parts by weight Methyl ethyl ketone 13 parts by weight Part Toluene 13 parts by weight

Example 2 A thermal transfer image-receiving sheet of Example 2 was prepared in the same manner as in Example 1 except that Barrier Layer Coating Solution 2 having the following composition was used instead of Example 1. [Composition of coating liquid for barrier layer 2] Polyester resin 30 parts by weight (Polyester WR-905 manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) Titanium oxide 20 parts by weight Water 50 parts by weight Isopropyl alcohol 50 parts by weight

(Example 3) A thermal transfer image-receiving sheet of Example 3 was prepared in the same manner as in Example 1 except that Barrier Layer Coating Solution 3 having the following composition was used instead of Example 1. [3 Compositions of Barrier Layer Coating Liquid] Polyurethane Resin 60 parts by weight (Dainippon Ink and Chemicals Hydran A-40) Polyvinyl alcohol 30 parts by weight (Nippon Gohsei Chemical Co., Ltd. Gohsenol KM-11) Titanium oxide 20 parts by weight Water 50 parts by weight Isopropyl alcohol 50 parts by weight

(Example 4) In place of Example 1, the coating liquid 1 for whitening layer having the following composition was used between the substrate sheet and the barrier layer so that the coating amount at the time of drying was 1 g / m ^2. A thermal transfer image-receiving sheet of Example 4 was prepared in the same manner as in Example 1 except for the above. [Composition of white coating layer coating liquid 1] Polyurethane resin 30 parts by weight (Nippon Polyurethane Co., Ltd. N-5247) Titanium oxide 20 parts by weight Methyl ethyl ketone 50 parts by weight Toluene 50 parts by weight

(Comparative Example 1) In place of Example 1, the coating solution 1 for white imparting layer and the coating solution 1 for receiving layer having the above-mentioned compositions were applied in order from the side of the substrate sheet, and otherwise the same as Example 1. Similarly,
A thermal transfer image-receiving sheet of Comparative Example 1 was prepared. (Comparative Example 2) In place of Comparative Example 1, a white coating layer coating liquid 2 having the following composition was used, and otherwise the same as in Comparative Example 1,
A thermal transfer image-receiving sheet of Comparative Example 2 was prepared. [Composition of white coating layer coating liquid 2] Chlorinated polypropylene resin 10 parts by weight (B-13 manufactured by Toyo Kasei Co., Ltd.) Titanium oxide 20 parts by weight Methyl ethyl ketone 45 parts by weight Toluene 45 parts by weight

The thermal transfer image-receiving sheet and the thermal transfer sheet prepared by the above-mentioned procedure were superposed on their respective receiving layer surfaces and dye layer surfaces, and heated from the back layer side of the thermal transfer sheet with a thermal head. Heating condition is applied voltage 14.5
V, applied pulse width 6.4 msec / line to 0.4
After printing was performed with a thermal head under the conditions of a step pattern which is sequentially decreased every msec and a condition of 6 line / mm (10 msec / line) in the sub-scanning direction to form an image, the printing state and adhesiveness of each image were examined.

With respect to the thermal transfer image-receiving sheets of the above Examples and Comparative Examples, the adhesiveness was evaluated by the following method, and the results shown in Table 1 below were obtained. (Adhesiveness) Scotch mending tape (manufactured by Sumitomo 3M Ltd.) was lightly attached to the surface of the receiving layer with fingers and slowly peeled by hand to evaluate adhesiveness. The evaluation criteria are as follows. ◯: The mending tape peels off cleanly from the receiving layer surface. X: Peeling is performed between the substrate sheet and the barrier layer or between the barrier layer and the receiving layer.

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[Table 1]

[0043]

According to the present invention, the use of a water-soluble resin in the barrier layer prevents migration of the metal source in the receiving layer, thereby preventing a decrease in adhesiveness with the base sheet and providing a clear image. It is possible to obtain a clear image.

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Claims (3)

[Claims] 1. A barrier layer whose main component is a water-soluble resin and a receiving layer containing a metal ion-supplying compound represented by the following general formula (1) are formed on a base sheet in this order from the side of the base sheet. A thermal transfer image-receiving sheet characterized by being provided. Formula (1) M ²⁺ (X ¹⁻ ) _m (2-n) Y ⁻ However, in the formula, M ²⁺ represents a divalent transition metal ion. X
Represents a coordination compound capable of forming a complex by coordination-bonding to the transition metal ion M ²⁺ , 1 represents an integer of 0 or 1, and m represents an integer of 2 or 3. The plurality of coordination compounds X may be the same as or different from each other. Y ^-
Represents a counter ion of the transition metal ion M ²⁺ , n is 0, 1,
Or an integer of 2. 2. The thermal transfer image-receiving sheet according to claim 1, wherein the barrier layer contains a white pigment. 3. The thermal transfer image-receiving sheet according to claim 1, wherein a white color imparting layer is provided on at least one of the upper and lower sides of the barrier layer.