JP2006015684A - Thermal transfer recording material and thermal transfer recording method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermal transfer recording material in which transfer properties are improved to make sensitivity higher and storing properties of a coloring matter providing material is improved, and a thermal transfer recording method using the recording material. <P>SOLUTION: The thermal transfer recording material comprises a compound of general formula 1 which causes cleavage of a bonding by heating and forms a metal chelate coloring matter image with a metal ion compound. In this general formula 1, Dye expresses a coloring matter; J expresses a group which causes cleavage by heating; Z expresses a group which releases with a part of J whose bonding is cleaved; and p is an integer of 1 or larger. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a thermal transfer recording material and a thermal transfer recording method thereof.

  Conventionally, as a method for obtaining a color hard copy, color image recording using an ink jet, electrophotography, thermal transfer, silver halide photosensitive material or the like has been studied. Among these, thermal transfer recording has advantages such as easy operation and maintenance, downsizing and cost reduction of the apparatus, and low running cost. In this thermal transfer recording, a dye used for a thermal transfer recording material (hereinafter also referred to as a thermal transfer material) is important.

For the purpose of improving the stability of the obtained image, particularly fixing and light resistance, a heat-sensitive transfer material and an image forming method using a chelatable heat-diffusible dye (hereinafter referred to as a chelate dye) have been proposed. (For example, refer to Patent Documents 1 and 2.) The image formed using the chelate dye disclosed in the above patent document is excellent in light resistance and fixability, but is not sufficiently satisfactory in terms of the sensitivity of the thermal transfer material and the storage stability of the material itself. In addition, since the hue difference between the chelate dye and the chelate dye is large, if the chelate reaction at the time of image formation is insufficient, absorption of the unreacted chelate dye remains or the chelate formed Since the dye itself has irregular absorption, when a full-color image is obtained, it is necessary to further improve the color reproduction. In particular, the dye of the thermal transfer recording material (for example, see Patent Documents 3 to 5) using a dye having a pyrazolopyrimidin-7-one mother nucleus has improved the above-mentioned problems to some extent. It cannot be said that the level is still sufficient, and the sensitivity is high and the storage stability of the thermal transfer recording material is insufficient, and further improvement has been desired.
JP-A 59-78893, page 1 1 page of JP-A-60-2398 JP-A-3-143684, page 1 JP-A-3-143686, page 1 JP-A-11-78258, pages 1-2

  An object of the present invention is to provide a thermal transfer recording material in which transferability is improved and sensitivity is improved, and storage stability of a dye-donating material is improved, and a thermal transfer recording method using the recording material.

  As a result of diligent research, the present inventors have found that the object of the present invention can be achieved by a thermal transfer recording material using a novel dye that causes bond cleavage by heating, and completed the present invention. That is, the above object of the present invention is achieved by the following configuration.

(Claim 1)
A thermal transfer recording material comprising a compound represented by the following general formula 1 which causes bond cleavage by heating and forms a metal chelate dye image with a metal ion compound.

(In the formula of general formula 1, Dye represents a dye, J represents a group that causes cleavage upon heating, Z represents a group that leaves together with a part of J that undergoes bond cleavage, and p represents an integer of 1 or more. )
(Claim 2)
2. The thermal transfer recording material according to claim 1, wherein ClogP changes by 2 or more due to bond cleavage caused by heating of the compound represented by the general formula 1.

(Claim 3)
The thermal transfer recording material according to claim 1 or 2, wherein the molecular weight of the compound represented by the general formula 1 is reduced to 80% or less by bond cleavage caused by heating.

(Claim 4)
The thermal transfer recording material according to claim 1, wherein Dye represented by the general formula 1 is a compound represented by the following general formulas 2 to 7.

(In the formulas 2 to 6, X ₁ and X ₂ represent a group that forms a dye via a conjugated system, and Y is a group of atoms that form a 5-membered or 6-membered aromatic carbocycle or heterocycle. In the general formula 7, X ₃ represents a group of atoms that can be bonded via a conjugated system, and Z ₁ and Z ₂ each form a nitrogen-containing heterocycle containing at least one nitrogen atom. Represents a group of atoms, and the heterocycles may be the same or different from each other, wherein R ₁ , R ₂ and R ₃ are each a hydrogen atom, a halogen atom or a monovalent Represents a substituent, and n represents 0, 1 or 2.)
(Claim 5)
The group represented by -J-Z in the compound represented by the general formula 1 is a group selected from the following general formulas 1a, 1b, 1c, and 1d. The thermal transfer recording material according to item.

(In the general formulas 1a, 1b, 1c, and 1d, Ra represents a substituted or unsubstituted alkyl group, aryl group, or cycloalkyl group, and Rb, Rc, and Rd represent a hydrogen atom, a substituted or unsubstituted alkyl group, An aryl group and a cycloalkyl group, Re represents a substituent, Rf represents a hydrogen atom or an alkyl group, and Yb ⁻ represents a counter anion.)
(Claim 6)
An image-receiving material having an image-receiving layer containing a metal ion-containing compound on a support is superposed on a dye-donating material having a dye-donating layer containing at least one compound represented by the general formula 1 on the support, A thermal transfer recording method, wherein a dye-donating material is heated in accordance with image information to form a metal chelate dye image by a reaction between the bond-cleavage dye and the metal ion-containing compound.

  According to the thermal transfer recording method using the thermal transfer recording material according to the present invention, it is possible to obtain an image in which the dye-donating material has good storage stability and can be recorded with high sensitivity.

  Hereinafter, the present invention will be described in more detail.

  In the present invention, the compound represented by the general formula (1) breaks the bond (J portion) by heating, thereby causing a change in logP. That is, it is considered that high log P is maintained during storage, whereby storage stability is improved, and after bond cleavage, low log P is obtained, transferability is improved, and high image density is given. The change in logP is preferably 2 or more, and the upper limit thereof is 10, and the change in molecular weight is preferably 80% or less of the original, and the lower limit thereof is 35%.

  In General Formula 1, Dye represents a dye, J represents a group that causes cleavage upon heating, and Z represents a group that leaves together with a part of J that undergoes bond cleavage. n represents an integer of 1 or more. Dye is not particularly limited as long as it has absorption in the visible light region, and preferably has absorption at 300 to 750 nm. Examples thereof include methine dyes, polymerine dyes, azo dyes, diazo dyes, and the like. J is not particularly limited as long as it is a group that causes bond cleavage upon heating, and is preferably a group that causes bond cleavage at 70 to 500 ° C, more preferably 100 to 300 ° C. Z is not particularly limited as long as it is a group capable of leaving together with a part of J after bond cleavage.

  In the present invention, ClogP uses a numerical value calculated by Chem Draw Ultra 7.0. ClogP after bond cleavage is a numerical value in a structure in which -JZ is deleted. In the present invention, the molecular weight after bond cleavage is the molecular weight obtained by deleting -JZ.

In General Formulas 2 to 6, X ₁ and X ₂ represent a group that forms a dye via a conjugated system, and Y represents a group of atoms that form a 5-membered or 6-membered aromatic carbocyclic or heterocyclic ring.

In general formula 7, X ₃ represents a group of atoms that can be bonded via a conjugated system, and Z ₁ and Z ₂ each represent a group of atoms that form a nitrogen-containing heterocycle containing at least one nitrogen atom. The heterocycles may be the same or different from each other.

In General Formulas 2 to 4 and General Formula 7, R ₁ , R ₂ , and R ₃ represent a hydrogen atom, a halogen atom, or a monovalent substituent, and n represents 0, 1, or 2.

X ₁ and X ₂ are preferably represented by the following general formulas 8 to 14.

In the general formulas 8 to 14, R ^{10 to} R ²³ represent a hydrogen atom or a monovalent substituent. L ⁵ represents a nitrogen atom or —CR ²⁶ —, L ⁶ represents a nitrogen atom or —CR ²⁷ ═, and L ⁷ represents a nitrogen atom or —CR ²⁸ ═, and R ²⁶ , R ²⁷ and R ²⁸ represent hydrogen. Represents an atom or a monovalent substituent. Examples of the monovalent substituent include a halogen atom (for example, fluorine atom and chlorine atom), an alkyl group (for example, methyl, ethyl, butyl, pentyl, 2-methoxyethyl, trifluoromethyl, 2-ethylhexyl, etc.). An aryl group (eg, phenyl, benzoyl, etc.), an alkoxy group (eg, methoxy, ethoxy, butoxy, etc.), an alkoxycarbonyl group (eg, methoxycarbonyl, i-propoxycarbonyl, etc.), an acyloxy group (eg, acetyloxy, ethyl) Carbonyloxy etc.), carbamoyl groups (eg methylcarbamoyl, ethylcarbamoyl, butylcarbamoyl, phenylcarbamoyl etc.), sulfamoyl groups (eg sulfamoyl, methylsulfamoyl, dimethylsulfamoyl, phenylsulfamoyl) ), Alkylthio groups (eg, methylthio, ethylthio, octylthio, etc.), arylthio groups (eg, phenylthio, p-tolylthio, etc.), amino groups (eg, amino, methylamino, diethylamino, methoxyethylamino, etc.), acylamino groups (Eg, acetylamino, chloroacetylamino, propionylamino, benzoylamino, trifluoroacetylamino, etc.), alkylureido groups (eg, methylureido, ethylureido, methoxyethylureido, dimethylureido, etc.), arylureido groups (eg, Phenylureido, etc.), alkylsulfonamide groups (for example, methanesulfonamide, ethanesulfonamide, butanesulfonamide, trifluoromethylsulfonamide, 2,2,2-trifluoroethyl) Sulfonamide etc.), arylsulfonamide groups (eg phenylsulfonamide, tolylsulfonamide etc.), alkylaminosulfonylamino groups (eg methylaminosulfonylamino, ethylaminosulfonylamino etc.), arylaminosulfonylamino groups (eg Phenylaminosulfonylamino, etc.), hydroxy group, cyano group, nitro group, heterocyclic group (for example, pyridyl, pyrimidyl, pyrazyl, pyrrolyl, indolyl, pyrazolyl, imidazolyl, furyl, oxazolyl, thiazolyl, quinolyl, thienyl, etc.) . The heterocyclic group may further have a substituent or may have a condensed ring, which may further have a substituent, and are further bonded to each other to form a 5- or 6-membered group. The ring may be formed.

  Y represents a group of atoms forming an aromatic carbocycle or a heterocycle, and the ring may further have a substituent or may have a condensed ring. Specific examples of the ring include a benzene ring, a pyridine ring, a pyrimidine ring, a furan ring, a thiophene ring, a thiazole ring, an imidazole ring, a naphthalene ring, a 3H-pyrrole ring, an oxazole ring, a 3H-pyrrolidine ring, an oxazolidine ring, and an imidazolidine. Ring, thiazolidine ring, 3H-indole ring, benzoxazole ring, benzimidazole ring, benzthiazole ring, quinoline ring, isoquinoline ring, indolenine ring, barbitur ring, thiobarbitur ring, rhodanine ring, hydantoin ring, pyrazolidine Examples include a dione ring and a pyridinedione ring. These rings may further form a condensed ring with another carbon ring (for example, benzene ring) or a heterocyclic ring (for example, pyridine ring). Substituents and substituents on the condensed ring include alkyl groups, aryl groups, acyl groups, amino groups, nitro groups, cyano groups, acylamino groups, alkoxy groups, hydroxyl groups, alkoxycarbonyl groups, halogen atoms, etc. The group may be further substituted.

In the general formula 7, X ₃ represents a group of atoms that can be bonded through a conjugated chain to form a dye, and specifically forms a 5-membered or 6-membered carbocyclic ring or heterocyclic ring. An atomic group or one represented by the following general formula 15 is preferred.

In the general formula 15, X ₄ and X ₅ each represent a cyano group, an alkoxycarbonyl group, an aryloxycarbonyl group, a carbamoyl group, an acyl group, an alkylsulfonyl group, an arylsulfonyl group, etc., and these are the same as each other. Or different.

When X ₃ forms a 5-membered or 6-membered carbocyclic or heterocyclic ring, the ring may be a monocyclic ring or a condensed ring. Specifically, a pyrrole ring, a pyridine ring, a pyrimidine ring, a triazine ring, a furan ring, a thiophene Ring, imidazole ring, benzimidazole ring, pyrazoloimidazole ring, pyrazole ring, oxazole ring, benzoxazole ring, thiazole ring, benzthiazole ring, isoxazole ring, isothiazole ring, triazole ring, benzotriazole ring, pyrazolotriazole ring, Tetrazole ring, thiadiazole ring, pyrazolotetrazole ring, oxadiazole ring, pyrazolotriazole ring, rhodanine ring, hydantoin ring, thiohydantoin ring, barbitur ring, thiobarbitur ring, oxazoline ring, oxazolidinedione ring, pyridinedione ring , Oxy Dole ring, pyrazolidinedione ring, quinoline ring, isoquinoline ring, 5-pyrazolone ring, oxazolone ring, isoxazolone ring, indandione ring, hydroxypyridone ring, pyrazolopyridone ring, pyrazolopyrrole ring, pyrazolopyrazole ring, etc. It is done.

  The carbocycle or heterocycle may be unsubstituted or substituted, and examples of the substituent atom and substituent include a halogen atom (eg, chlorine atom, bromine atom), an alkyl group (eg, methyl group, ethyl group, isopropyl). Group, hydroxyethyl group, methoxymethyl group, trifluoromethyl group, t-butyl group, etc.), cycloalkyl group (eg, cyclopentyl group, cyclohexyl group, etc.), aralkyl group (eg, benzyl group, 2-phenethyl group, etc.), An aryl group (for example, phenyl group, naphthyl group, p-tolyl group, p-chlorophenyl group, etc.), an alkoxy group (for example, methoxy group, ethoxy group, isopropoxy group, n-butoxy group, etc.), an aryloxy group (for example, Phenoxy group, etc.), cyano group, acylamino group (for example, acetylamino group, propionylamino group) ), Alkylthio groups (eg, methylthio group, ethylthio group, n-butylthio group, etc.), arylthio groups (eg, phenylthio group, etc.), sulfonylamino groups (eg, methanesulfonylamino group, benzenesulfonylamino group, etc.), ureido groups (Eg, 3-methylureido group, 3,3-dimethylureido group, 1,3-dimethylureido group, etc.), sulfamoylamino group (eg, dimethylsulfamoylamino group, etc.), carbamoyl group (eg, methyl Carbamoyl group, ethylcarbamoyl group, dimethylcarbamoyl group, etc.), sulfamoyl group (eg, ethylsulfamoyl group, dimethylsulfamoyl group, etc.), alkoxycarbonyl group (eg, methoxycarbonyl group, ethoxycarbonyl group, etc.), aryloxy Carbonyl group (eg For example, phenoxycarbonyl group etc.), sulfonyl group (eg methanesulfonyl group, butanesulfonyl group, phenylsulfonyl group etc.), acyl group (eg acetyl group, propanoyl group, butyroyl group etc.), amino group (eg methylamino) Group, ethylamino group, dimethylamino group etc.), hydroxyl group, nitro group, nitroso group, amine oxide group (eg pyridine oxide group), imide group (eg phthalimide group etc.), disulfide group (eg benzene disulfide group) Benzothiazolyl-2-disulfide group), heterocyclic groups (eg, pyridyl group, benzimidazolyl group, benzthiazolyl group, benzoxazolyl group, etc.), carboxyl group, sulfo group and the like.

Z ₁ and Z ₂ each represent a group of atoms forming a nitrogen-containing heterocycle containing at least one nitrogen atom, and these may be the same or different from each other. Specifically, a pyrrole ring, a pyridine ring, a pyrimidine ring , Triazine ring, imidazole ring, benzimidazole ring, pyrazoloimidazole ring, pyrazole ring, oxazole ring, benzoxazole ring, thiazole ring, benzthiazole ring, isoxazole ring, isothiazole ring, triazole ring, benzotriazole ring, pyrazolotriazole ring , Tetrazole ring, thiadiazole ring, pyrazolotetrazole ring, oxadiazole ring, pyrazolotriazole ring, pyridinedione ring, oxindole ring, pyrazolidinedione ring, quinoline ring, isoquinoline ring, 5-pyrazolone ring, oxazolone ring, Indanji Down ring, isoxazolone ring, indandione ring, hydroxypyridone ring, pyrazolopyridone ring, pyrazolone pyrrole rings include pyrazolo pyrazole ring.

In general formulas 2 to 4 and general formula 7, R ₁ , R ₂ , and R ₃ represent a hydrogen atom, a halogen atom (for example, a fluorine atom, a chlorine atom, etc.) or a monovalent substituent. Examples thereof include an alkyl group, an alkoxy group, a cyano group, an alkoxycarbonyl group, an aryl group, a heterocyclic group, a carbamoyl group, a hydroxyl group, an acyl group, and an acylamino group. n represents 0, 1 or 2.

  Although the specific example of the compound represented by General formula 1 which concerns on this invention below is given, this invention is not limited to these.

  The synthesis example of the compound represented by the general formula 1 according to the present invention is shown below. Other compounds can also be synthesized using similar synthesis methods or known synthesis methods.

  [Synthesis of Exemplified Compound (3)]

  (3-1) 10 g (0.103 mol), (3-2) 40.2 g (0.108 mol) and p-toluenesulfonic acid monohydrate 2.3 g (0.0123 mol) were added to 100 ml of toluene. The mixture was heated to reflux with stirring for 3 hours. After completion of the reaction, the solvent was removed under reduced pressure, and 120 ml of acetonitrile was added to the residue for recrystallization. The crystals were filtered to obtain 35.4 g (yield 85%) of (3-3).

  (3-3) 35 g (0.0865 mol) and 27.5 g (0.26 mol) of sodium carbonate are put in a reaction vessel, and 105 ml of ethyl acetate, 10 ml of water and 50.8 g of Trax K-40 (manufactured by NOF Corporation) are added. And dissolved at 40 ° C. An aqueous solution of (3-4) 5.94 g (0.02768 mol) in 10 ml of water was added to the mixture, and then sodium persulfate 13.2 g (0.05536 mol) and sodium carbonate 11.7 g (0.11 mol) were added. ) Was dissolved in 20 ml of water. Stirring was continued for 1 hour at 40 ° C., and thereafter the operation of the underlined portion was repeated every hour for a total of 4 times. After completion of all additions, the mixture was further reacted for 1 hour and then allowed to cool to room temperature. The precipitated crystals were filtered, washed 3 times with 50 ml of warm water and dried. The resulting coarse crystallization was recrystallized from 150 ml of acetonitrile. The crystals were filtered to obtain 34 g (yield 68%) of Exemplary Compound (3). The structure was confirmed by NMR spectrum and Mass spectrum.

[Measurement of absorption wavelength of Exemplified Compound (3)]
The absorption maximum of the exemplified compound (3) in the acetone solution is 605 nm (absorption coefficient 48000), and the absorption of the mixture of the exemplified compound (3) and the 100-fold molar metal ion-containing compound (MS-1) in the acetone solution. The maximum was 625 nm (absorption coefficient 110000).

MS-1: Ni (II) [C 7 H 15 CO (COOC 2 H 5) CHCOCH 3] 2
The heat-sensitive transfer material of the present invention comprises a dye-donating material having a dye-donating layer containing a compound represented by the general formula 1 according to the present invention on a support. The dye-donating layer is prepared by dissolving the compound represented by the general formula 1 in a solvent together with a binder or by dispersing the compound in a fine particle form in a solvent to form an ink liquid for forming a dye-donating layer. It can be formed by coating and drying appropriately. The thickness of the dye-donating layer is preferably 0.1 to 10 μm as a dry film thickness.

As the binder, solvent-soluble polymers such as acrylic resin, methacrylic resin, polystyrene, polycarbonate, polysulfone, polyethersulfone, polyvinyl butyral, polyvinyl butyral, polyvinyl acetal, nitrocellulose, and ethylcellulose are preferable. These binders may be used in the form of latex dispersion as well as one or more dissolved in an organic solvent. The amount of the binder used is preferably 0.1 to ²⁰ g per 1 m ² of the support.

  Organic solvents include alcohols (ethanol, propanol, etc.), cellosolves (methyl cellosolve, ethyl cellosolve, etc.), aromatics (toluene, xylene, etc.), esters (ethyl acetate, etc.), ketones (acetone, methyl ethyl ketone, etc.) ), Ethers (tetrahydrofuran, dioxane, etc.) and the like.

  The support may be any material as long as it has good dimensional stability and can withstand the heat of a thermal head during recording. However, it has a heat resistance such as condenser paper, thin paper such as glassine paper, polyethylene terephthalate, polyamide, and polycarbonate. A plastic film is preferably used. The thickness of the support is preferably 2 to 30 μm.

  Further, the support preferably has an undercoat layer made of a polymer selected for the purpose of improving the adhesiveness with the binder and preventing the transfer and dyeing of the dye to the support. Further, a slipping layer may be provided on the back surface (the side opposite to the dye-donating layer) of the support for the purpose of preventing the head from sticking to the support.

  The heat-sensitive transfer material of the present invention is described in JP-A-59-106997 as a dye-donating layer or as a separate layer for the purpose of using a later-described image-receiving material that does not have an image-receiving layer like plain paper. You may have a heat-meltable layer containing such a heat-meltable compound. As the hot-melt compound, a colorless or white compound that melts at a temperature of 65 to 150 ° C. is preferable, and waxes such as carnauba wax, beeswax, and candelin wax are used.

  The heat-meltable layer may contain polymers such as polyvinyl pyrrolidone, polyvinyl butyral, polyester, and vinyl acetate.

  To apply the heat-sensitive transfer material of the present invention to full-color image recording, a yellow dye-donating layer containing a heat-diffusible yellow dye capable of forming a yellow image, and a magenta dye-donating containing a heat-diffusible magenta dye capable of forming a magenta image Preferably, a total of three layers of a cyan dye-donating layer containing a heat-diffusible cyan dye capable of forming a cyan image are successively and repeatedly coated on the same surface on the support. Further, if necessary, a total of four other dye-donating layers containing a black image-forming substance may be successively applied on the same surface.

  In the thermal transfer recording method of the present invention, an image-receiving material is superimposed on a dye-donating material having a dye-donating layer containing at least one compound represented by the general formula 1 on a support, and the dye-donating material is used. Heating is performed according to the image information, and the dye is transferred to form an image.

  Furthermore, it is preferable to use a compound represented by the general formula 1 according to the present invention in combination with a metal ion-containing compound. That is, an image receiving material having an image receiving layer containing a metal ion-containing compound on a support is superimposed on a dye donating material having a dye donating layer containing at least one compound represented by formula 1 on the support. The dye-donating material is heated according to image information, and a metal chelate dye image is formed by a reaction between the dye and the metal ion-containing compound. This metal ion-containing compound may be present in the image-receiving material or may be present in the hot-melt layer of the dye-donating material.

  Examples of the metal ion-containing compound include inorganic or organic salts and metal complexes of metal ions, and among them, salts and complexes of organic acids are preferable.

Examples of the metal include monovalent and polyvalent metals belonging to Groups V to VIII of the periodic table, among which Al, Co, Cr, Cu, Fe, Mg, Mn, Mo, Ni, Sn, Ti and Zn is preferable, and Ni, Cu, Cr, Co and Zn are particularly preferable. Specific examples of the metal ion-containing compound include salts of Ni ²⁺ , Cu ²⁺ , Cr ²⁺ , Co ²⁺ and Zn ²⁺ with aliphatic acids such as acetic acid and stearic acid, benzoic acid, salicylic acid, etc. And salts thereof with aromatic carboxylic acids. Moreover, the complex represented by the following general formula (I) can be particularly preferably used.

General formula (I) [M (Q ₁ ) _a (Q ₂ ) _b (Q ₃ ) _c ] ^{r +} (G ⁻ ) _s
In the formula, M represents a metal ion, preferably Ni ²⁺ , Cu ²⁺ , Cr ²⁺ , Co ²⁺ , Zn ²⁺ . Q ₁ , Q ₂ , and Q ₃ each represent a coordination compound capable of coordination with the 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) (Nan Edo). G ^- represents an organic anion group, and specific examples thereof include tetraphenyl boron anion and alkylbenzene sulfonate anion. a represents 1, 2 or 3; b represents 1, 2 or 0; c represents 1 or 0; in these, the complex represented by the general formula (I) is tetradentate or hexadentate. Depending on the number of ligands of Q ₁ , Q ₂ , Q ₃ . r represents 0, 1 or 2; r = 0 means 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. To do. S represents a numerical value necessary for neutralization when r is 1 or 2.

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

General formula (II) O ^- C (Ra) = CH (Rb) CORc
In the formula, Ra and Rb each represent an alkyl group or an aryl group which may be the same or different, and Rc represents an alkyl group, an alkoxy group, an alkoxycarbonyl group, a halogen atom or a hydrogen atom.

The addition amount of the metal ion-containing compound is usually preferably 0.5 to 20 g / m ^{2 and} more preferably 1 to 15 g / m ² with respect to the image receiving material or the heat-meltable layer.

  An image receiving material for forming an image with a metal complex dye is generally a paper, plastic film, or paper-plastic film composite as a support, and a polyester resin, polyvinyl chloride resin, vinyl chloride and other monomers as an image receiving layer thereon. It is formed by forming a polymer layer composed of one or more of a copolymer resin with (vinyl acetate and the like), polyvinyl butyral, polyvinyl pyrrolidone, polycarbonate and the like. The image receiving material may contain an antioxidant, a release agent, etc. in the image receiving layer as necessary, and a protective layer may be provided on the image receiving layer, and further between the support and the image receiving layer. An intermediate layer may be provided for the purpose of bonding, heat insulation or cushioning. Further, an antistatic layer and a back layer containing inorganic or organic non-sublimable fine particles may be provided on the back surface (the side opposite to the image receiving layer) of the support for the purpose of preventing blocking. An image receiving layer may be provided on both sides of the support. The support itself may be used as an image receiving material.

  Heating by a thermal head is generally used for the thermal transfer recording method, but current heating or heating using a laser may be used. The application of heat by a thermal head or the like may be performed from the back side of the dye-donating material or the back side of the image-receiving material without any particular limitation. However, in consideration of the transfer speed of the dye and the image density, the dye-donating material It is preferable to carry out from the back side. Further, the dye can be further heated before, during or after transfer of the dye to promote dye transfer, promote reaction with the metal ion-containing compound, and promote fixing of the transfer dye.

  Next, an example of the thermal transfer recording method of the present invention will be described with reference to FIGS.

  In the heat-sensitive transfer recording material of FIG. 1, the image receiving material 3 has a structure in which an image receiving layer 2 containing a metal ion-containing compound is provided on a support 1, and the dye-donating material 6 is formed on the support 4 according to the present invention. This is a configuration in which a dye-donating layer 5 containing the compound represented by the general formula 1 is provided. The image receiving material 3 and the dye donating material 6 may each be provided with an intermediate layer between the support.

  As the thermal transfer recording method, the image receiving material 3 and the dye donating material 6 are overlapped, and heat corresponding to the image information is applied from the back side of the dye donating material 6 by the heating resistor 8 carried on the thermal head 7, Peel both materials. At that time, a metal complex dye image is formed by a reaction between the dye from the dye-donating layer 5 and the metal ion-containing compound in the image receiving layer 2.

  In the heat-sensitive transfer recording material of FIG. 2, a heat-sensitive transfer recording material 10 in which a heat-meltable layer 9 containing a metal ion-containing compound is laminated on the dye-donating material 6 (4 + 5) of the heat-sensitive transfer recording material of FIG. Then, the image receiving material 3 not provided with an image receiving layer, such as the above-mentioned plain paper, is superposed and the thermal head 7 is used in the same manner as the thermal transfer recording method of FIG. . In the case of this method, when heat is applied by the thermal head 7, a metal complex dye image is formed by a reaction between the dye and the metal ion-containing compound between the dye-donating layer 5 and the heat-meltable layer 9 on the thermal transfer recording material 10. After which an image is received on the image receiving material 3.

  The present invention will be described more specifically with reference to the following examples. However, the present invention is not limited to these examples.

Example 1
[Preparation of thermal transfer recording material]
(Preparation of ink)
The following raw materials were mixed to obtain a uniform solution ink containing the coloring matter of the present invention. The solubility of the coloring matter was good, and the ink suitability was also good.

Comparative dye 1 0.72 g
Polyvinyl acetoacetal resin (KY-24: Denki Kagaku Kogyo) 1.08 g
Methyl ethyl ketone 26.4ml
Toluene 1.6ml
(Preparation of dye-donating material)
The ink is applied onto a polyethylene terephthalate (PET) base having a thickness of 4.5 μm using a wire bar, dried so that the coating amount after drying is 2.3 g / m ² , and a dye is provided on the PET film. A dye-donating material 1 having a layer was prepared. A nitrocellulose layer containing a silicon-modified urethane resin (SP-2105: manufactured by Dainichi Seika) is provided on the back surface of the PET base as an anti-sticking layer.

  Dye-donating materials 2 to 20 were prepared in the same manner except that the dye of dye-donating material 1 was replaced with the dye shown in Table 1.

(Production of image receiving material)
On a support laminated with polyethylene on both sides of paper (including white pigment (titanium dioxide) and bluing agent on one polyethylene layer), the coating amount after drying a coating solution of the following composition is 7.2 g / m ^It was coated and dried so as to be ² to prepare an image receiving material.

Metal ion-containing compound (MS-2) 4.0 g
Polyvinyl butyral resin (BX-1: Sekisui Chemical Co., Ltd.) 6.0 g
Polyester modified silicon 0.3g

[Thermal transfer recording]
The dye-donating material and the image-receiving material were superposed, and a thermal head was applied from the back surface of the dye-donating material, and image recording was performed with a thermal printer to obtain images 1 to 20 having excellent gradation. The maximum density of the obtained image, the sensitivity of the dye-donating material, and the storage stability were evaluated as follows.

《Maximum concentration》
The maximum reflection density of the image (usually the portion with the maximum application time) was measured with a densitometer X-rite 310TR (manufactured by X-rite).

"sensitivity"
The relative applied energy of each recording material when the applied energy when the density of the image 1 formed with the dye-providing material 1 is 1.0 is determined. The smaller the number, the higher the sensitivity.

<Preservation>
Three identical dye-donating materials are sandwiched between glass plates with the PET base side facing down, and a weight is placed on top of the same to give 1.96 × 10 ⁵ Pa (N / m ² ). The peeling of the dye from the lowermost dye-donating material to the second dye-donating material when allowed to stand at 90 ° C. and 90% RH (relative humidity) for 4 days was evaluated. Evaluation was performed visually and judged by the presence or absence of a peeling pigment. The results are also shown in Table 1.

  As shown in Table 1, the dye-donating material using the compound represented by Formula 1 according to the present invention has high sensitivity, can obtain a high-density image, and has good storage stability of the dye-donating material.

1 is a schematic cross-sectional view showing a heat-sensitive transfer recording material of the present invention. It is a schematic cross-sectional view showing a heat-sensitive transfer recording material having a heat-meltable layer.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Support body 2 Image receiving layer 3 Image receiving material 4 Support body 5 Dye-donating layer 6 Dye-donating material 7 Thermal head 8 Heating resistor 9 Hot-melting layer 10 Thermal transfer recording material

Claims (6)

A thermal transfer recording material comprising a compound represented by the following general formula 1 which causes bond cleavage by heating and forms a metal chelate dye image with a metal ion compound.

(In the formula of general formula 1, Dye represents a dye, J represents a group that causes cleavage upon heating, Z represents a group that leaves together with a part of J that undergoes bond cleavage, and p represents an integer of 1 or more. ) 2. The thermal transfer recording material according to claim 1, wherein ClogP changes by 2 or more due to bond cleavage caused by heating of the compound represented by the general formula 1. The thermal transfer recording material according to claim 1 or 2, wherein the molecular weight of the compound represented by the general formula 1 is reduced to 80% or less by bond cleavage caused by heating. The thermal transfer recording material according to claim 1, wherein Dye represented by the general formula 1 is a compound represented by the following general formulas 2 to 7.

(In the formulas 2 to 6, X ₁ and X ₂ represent a group that forms a dye via a conjugated system, and Y is a group of atoms that form a 5-membered or 6-membered aromatic carbocycle or heterocycle. In the general formula 7, X ₃ represents a group of atoms that can be bonded via a conjugated system, and Z ₁ and Z ₂ each form a nitrogen-containing heterocycle containing at least one nitrogen atom. Represents a group of atoms, and the heterocycles may be the same or different from each other, wherein R ₁ , R ₂ and R ₃ are each a hydrogen atom, a halogen atom or a monovalent Represents a substituent, and n represents 0, 1 or 2.) The group represented by -J-Z in the compound represented by the general formula 1 is a group selected from the following general formulas 1a, 1b, 1c, and 1d. The thermal transfer recording material according to item.

(In the general formulas 1a, 1b, 1c, and 1d, Ra represents a substituted or unsubstituted alkyl group, aryl group, or cycloalkyl group, and Rb, Rc, and Rd represent a hydrogen atom, a substituted or unsubstituted alkyl group, An aryl group and a cycloalkyl group, Re represents a substituent, Rf represents a hydrogen atom or an alkyl group, and Yb ⁻ represents a counter anion.) An image-receiving material having an image-receiving layer containing a metal ion-containing compound on a support is superposed on a dye-donating material having a dye-donating layer containing at least one compound represented by the general formula 1 on the support, A thermal transfer recording method, wherein a dye-donating material is heated in accordance with image information to form a metal chelate dye image by a reaction between the bond-cleavage dye and the metal ion-containing compound.

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