JPH06262863A - Thermal transfer material - Google Patents

Abstract

PURPOSE:To obtain a thermal transfer material excellent in various characteristics required by a thermal transfer dye, especially, in solubility, sensitivity and light fastness by providing a thermal transfer layer containing a dye represented by a specific general formula on a support. CONSTITUTION:One or more kind of a dye represented by formula I and/or formula II [wherein X is an atom group necessary for forming an aromatic ring fused to a pyrazolone ring, R1 is a hydroxyl group, a salt of a hydroxyl group or N(R3)R4, R2 is H or a monovalent group, n is an integer of 0-3 and R3 and R4 are H, an alkyl group or an allyl groupl is dissolved in a solvent such as ethyl acetate along with a binder such as an acrylic resin to prepare an ink soln. for forming a thermal transfer layer. This ink soln. is applied to a support such as tissue paper or a plastic film and dried to form the thermal transfer layer to obtain a thermal transfer material. Further, a slipping layer can be provided to the rear surface of the support for the purpose of preventing the sticking of a head to the support.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to thermal transfer materials.

[0002]

2. Description of the Related Art Conventionally, a method using a heat-sensitive transfer material is known as a method for obtaining an image, particularly a high-quality full-color image, by a simple and dry process. Dyes used for forming a color image are particularly important in heat-sensitive transfer materials, and various dyes for heat-sensitive transfer materials have been proposed.

As a dye for thermal transfer, use of an azomethine dye synthesized by a coupling reaction between a coupler and an oxidized product of a p-phenylenediamine derivative or p-aminophenol is disclosed in, for example, JP-A-63-205288.
No. 64-63194, JP-A-3-83687,
No. 3-83688, No. 3-83689, No. 3-11
No. 4890, No. 3-90387, No. 3-92385
No. 3-92386, U.S. Pat. No. 4,829,048.
No., etc. have been proposed and some have been put to practical use. However, these known dyes used for thermal transfer do not satisfy all the performances required as a dye for thermal transfer, such as sensitivity, color tone, ease of synthesis, solubility, and image storability. , And there has been a strong demand for further improvement. In addition,
No. 7 discloses 3-indazolinone derivative and N, N-dialkyl
A thermal transfer material using an indazolone dye produced by oxidative coupling with a -p-phenylenediamine derivative is disclosed. This pigment has excellent color tone,
The solubility, sensitivity, and light resistance of the dye in an organic solvent are not yet at a satisfactory level, and further improvement has been required.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to improve the above problems of the prior art. That is, an object of the present invention is to provide a heat-sensitive transfer material using a novel dye which has improved various properties required for the dye for heat-sensitive transfer, particularly solubility, sensitivity and light resistance.

[0005]

As a result of earnest studies, the present inventors have found that in a heat-sensitive transfer material having a layer containing a dye on a support, (1) the dye has the following general formula (1) and / or A heat-sensitive transfer material represented by the general formula (2).

[0006]

[Chemical 3]

[Wherein X represents an atomic group necessary for forming an aromatic ring fused to a pyrazolone ring, R ₁ represents a hydroxyl group,
It represents a salt of a hydroxyl group or -N (R ₃ ) R ₄ . R ₂ represents a hydrogen atom or a monovalent group.

N represents an integer of 0 to 3. R ₃ and R ₄ are each independently a hydrogen atom, an alkyl group, an aralkyl group,
It represents a cycloalkyl group, an aryl group, or a heterocyclic group. Two R ₂ , R ₃ and R ₄ , R ₂ and R ₃ , and R ₂ and R ₄ may combine with each other to form a ring. (2) In a heat-sensitive transfer material having a layer containing a dye on a support, the above-mentioned object can be achieved by the heat-sensitive transfer material characterized in that the dye is represented by the following general formula (3). It was

[0009]

[Chemical 4]

[In the formula, Y represents an atomic group necessary for forming an aromatic heterocycle condensed with a pyrazolone ring, and R ₅ represents a hydroxyl group, a salt of a hydroxyl group, or —N (R ₇ ) R ₈ ). R6 represents a hydrogen atom or a monovalent group.

M represents an integer of 0 to 4. R7 and R8 each independently represent a hydrogen atom, an alkyl group, an aralkyl group, a cycloalkyl group, an aryl group, or a heterocyclic group. Two R ₆ , R ₇ and R ₈ , R ₆ and R ₇ , and R ₆ and R
₈ may combine with each other to form a ring. The present invention is a heat-sensitive transfer material having a layer containing a dye on a support, wherein the dye has an aromatic heterocycle as a partial structure. Surprisingly, the dye of the present invention has remarkably improved sensitivity, solubility and light fastness as compared with the similar dye described in JP-B-4-48357.

The dye of the present invention will be described in more detail below.

In the general formulas (1) and (2), as the aromatic ring condensed with the pyrazolone ring represented by X, an aromatic carbocycle represented by a benzene or naphthalene ring: O, S, and N atoms A 5- or 6-membered aromatic heterocycle having at least one kind in the ring (for example, a 6-membered ring azine such as pyridine, pyrazine, or pyrimidine ring and its benzerogue: pyrrole,
Thiophene, furan and its benzerogue: 5-membered ring azoles such as imidazole, thiazole and oxazole and its benzerogue. Among them, benzene ring, pyridine ring and thiophene ring are particularly preferable. In the general formula (3), as the aromatic heterocycle fused to the pyrazolone ring represented by Y, O, S, and
A 5- or 6-membered aromatic heterocycle having at least one kind of N atom in the ring (for example, a 6-membered ring azine such as pyridine, pyrazine or pyrimidine ring and its benzerogue: pyrrole, thiophene, furan and its benzerogue: imidazole, 5-membered ring azoles such as thiazole and oxazole and benzerogues thereof can be mentioned. Of these, a pyridine ring and a thiophene ring are particularly preferable.

The aromatic ring represented by X and Y may have a substituent on the ring, and examples of the substituent include a halogen atom (chlorine atom, bromine atom, etc.), an alkyl group (eg, methyl group, ethyl group). 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.), aryl group (eg, phenyl group, naphthyl group) Group, p-tolyl group, p-chlorophenyl group etc.), alkoxy group (eg methoxy group, ethoxy group, isopropoxy group, n-butoxy group etc.), aryloxy group (eg phenoxy group etc.), cyano group, acylamino Group (eg acetylamino group, propionylamino group etc.), alkylthio group (eg methylthio group, ethylthio group, n-butylthio group etc.), arylthio group (eg phenylthio group etc.), sulfonylamino group (eg methanesulfonylamino group, benzene) Sulfonylamino group, etc., ureido group (eg Place 3-methylureido group,
3,3-dimethylureido group, 1,3-dimethylureido group, etc.), sulfamoylamino group (dimethylsulfamoylamino group, etc.), carbamoyl group (eg, methylcarbamoyl group, ethylcarbamoyl group, dimethylcarbamoyl group, etc.) , A sulfamoyl group (eg, ethylsulfamoyl group, dimethylsulfamoyl group, etc.), an alkoxycarbonyl group (eg, methoxycarbonyl group, ethoxycarbonyl group, etc.), an aryloxycarbonyl group (eg, phenoxycarbonyl group, etc.), a sulfonyl group (eg, Methanesulfonyl group, butanesulfonyl group, phenylsulfonyl group etc.), acyl group (eg acetyl group, propanoyl group, butyroyl group etc.), amino group (methylamino group, ethylamino group, dimethylamino group etc.), hydroxy group, nitro Base, Bromide group (e.g. phthalimido group), a Hajime Tamaki (e.g., pyridyl, benzimidazolyl group, benzothiazolyl group, benzoxazolyl group).

The monovalent group represented by R ₂ may be the same as the above-mentioned substituents on the aromatic ring.

R ₆ has the same meaning as R ₂ .

As the alkyl group, aralkyl group, cycloalkyl group, aryl group, or heterocyclic group represented by R ₃ and R ₄ , specifically, the alkyl group, aralkyl group, cycloalkyl group, aryl which are mentioned as R ₂ The same thing as a group or a heterocyclic group can be mentioned.

Examples of the group substituted on the alkyl group, aralkyl group, cycloalkyl group, aryl group or heterocyclic group represented by R ₃ and R ₄ include the same groups as R ₂ .

Specific examples of R ₃ and R ₄ bonded to each other to form a ring include a pyrrolidine ring, a piperidine ring, and a morpholine ring.

A benzene ring can be mentioned as a specific example of the combination of two R ₂ 's to form a ring.

Specific examples of R ₂ and R ₃ and R ₂ and R ₄ which are bonded to each other to form a ring include:

[0022]

[Chemical 5]

And the like.

R ₇ and R ₈ have the same meaning as R ₃ and R ₄ .

Specific examples of R ₆ and R ₇ and R ₆ and R ₈ bonded to each other to form a ring include:

[0026]

[Chemical 6]

And the like.

The salt of the hydroxyl group represented by R ₁ and R ₅ is preferably represented by the general formula A.

In the general formula A ^-- O ^-- Z ⁺ formula, Z ⁺ represents a monovalent organic or inorganic cation, and the inorganic cation is preferably sodium or potassium cation. The organic cation is preferably a proton adduct of an organic base or a quaternary ammonium cation, and the organic base is preferably an alkylamine (eg, methylamine, diethylamine, triethylamine, etc.), an arylamine (eg, aniline, diphenylamine, N, N-dimethylaniline etc.), amidines (benzamidine, acetamidine, 1,5-diazobicyclo [4,3,0] -5-nonene, 1,8-diazabicyclo [5,4,0] -7-
Undecene etc.), guanidines (eg tetramethylguanidine, diphenylguanidine, dimethyldiphenylguanidine, dipiperidguanidine, bisguanidine etc.), nitrogen-containing heterocyclic compounds (eg pyridine, quinoline, imidazole, pyrrolidine, morpholine, 4-N) , N-dimethylaminopyridine, etc.). Examples of quaternary ammonium cations include cations such as tetramethylammonium, tetraethylammonium, trimethylbenzylammonium, and tetrabutylammonium.

Specific examples of the dye of the present invention include the following compounds, but the present invention is not limited thereto. .

[0031]

[Chemical 7]

[0032]

[Chemical 8]

[0033]

[Chemical 9]

The dye represented by the general formula (1) or (2) is represented by the general formula (5) or the general formula (6) in the presence of an indazolone derivative represented by the general formula (4) in the presence of an alkali. It can be produced by oxidative coupling with a pyridineamine derivative.

[0035]

[Chemical 10]

The dye represented by the general formula (3) is produced by oxidative coupling of the indazolone derivative represented by the general formula (7) with the aniline derivative represented by the general formula (8) in the presence of an alkali. You can

[0037]

[Chemical 11]

Further, in the dye of the present invention in which R ₁ and R ₅ are salts of hydroxyl groups, the dye of the present invention in which R ₁ and R ₅ are hydroxyl groups and the above-mentioned inorganic or organic base are mixed with a suitable organic solvent (for example, It is obtained by mixing in ethyl acetate, acetone, methanol, etc.). Further, by mixing the obtained dye with a quaternary ammonium salt (eg, tetramethylammonium chloride, tetrabutylammonium bromide, trimethylbenzylammonium bromide, etc.) under the same conditions, a dye of the present invention having a quaternary ammonium cation can be obtained. .

Next, a heat-sensitive transfer material using the dye of the present invention will be described.

The heat-sensitive transfer material of the present invention has a dye-containing layer containing at least a dye and a binder on a support.

As the binder, acrylic resin, methacrylic resin, polystyrene, polycarbonate, polysulfone, polyether sulfone, polyvinyl butyral,
Solvent-soluble polymers such as polyvinyl acetal, nitrocellulose, ethyl cellulose are preferred. These binders may be used not only in the form of one or more dissolved in an organic solvent, but also in the form of latex dispersion. The amount of binder used is 0.1 per 1 m ² of the support.
~ 20g is preferred.

The dye-containing layer is prepared by dissolving one or more dyes of the present invention together with a binder in a solvent (eg ethyl acetate, acetone, ethyl methyl ketone, cyclohexanone, methanol, ethanol, toluene). Alternatively, it can be formed by adjusting the ink liquid for forming the heat-sensitive transfer layer by dispersing it in the form of fine particles in a solvent, applying the ink on a support, and drying it appropriately. As the content of dye, the support is 1 m ²
It is preferably 0.1 g to 20 g. The thickness of the dye-containing layer is preferably 0.1 to 10 μm as a dry film thickness.

The support of the present invention may be any one as long as it has good dimensional stability and can withstand the heat of a thermal head or the like during recording, but thin paper such as condenser paper or glassine paper,
A heat resistant plastic film such as polyethylene terephthalate, polyamide or polycarbonate is preferably used. The thickness of the support is preferably 2 to 30 μm, and the support has an undercoat layer made of a polymer selected for the purpose of improving the adhesiveness with a binder and preventing the transfer of dyes to the support and dyeing. It is preferable to have Further, the back surface of the support (on the side opposite to the dye-containing layer) may have a slipping layer for the purpose of preventing the head from sticking to the support.

To apply the heat-sensitive transfer material of the present invention to a heat-sensitive transfer material capable of full-color image recording, a yellow heat-sensitive transfer layer containing a yellow dye, a magenta heat-sensitive transfer layer containing a magenta dye, and a cyan dye are contained. It is preferable that a total of three layers of the cyan thermal transfer layer are sequentially and repeatedly coated on the same surface of the support. If necessary, a total of four heat-sensitive transfer layers containing a black image forming substance may be sequentially and repeatedly coated on the same surface.

When an image is recorded using the heat-sensitive transfer material of the present invention, the dye-containing layer of the heat-sensitive transfer material and the image-receiving material are superposed, and then heat (for example, a thermal head or infrared laser) is applied in accordance with the image information. Can be used as a heat source) to the heat-sensitive transfer recording material to thermally transfer the dye to the image-receiving material, whereby an image can be formed on the image-receiving material.

As the image receiving material, a material having an image receiving layer on a support is used. As the support of the image receiving material,
Paper, plastic film, or paper-plastic film composites can be used. Specific examples of the support include those described in JP-A-3-54556, page 5, upper right line 17 to lower left line 11.

The image receiving layer is composed of a polymer binder. The polymer binder is preferably a thermoplastic polymer such as polyester resin, polyvinyl chloride resin, vinyl chloride and other monomers (eg vinyl acetate)
And one or more polymer layers of a copolymer resin, polyvinyl butyral, polyvinyl pyrrolidone, polycarbonate and the like are formed. In addition, an image stabilizer such as a UV absorber and an antioxidant is added if necessary.

[0048]

The present invention will be described in detail below with reference to examples, but the embodiments of the present invention are not limited thereto.

Example (1) Synthesis of Dye (Synthesis of Exemplified Dye M-1) (Synthesis Scheme)

[0050]

[Chemical 12]

Coupler 5.0 g, 2-methyl-3-amino-6-N, N-
A solution of 9.8 g of diethylaminopyridine dissolved in 200 ml of methanol and 15 g of potassium carbonate dissolved in 50 ml of water was added. While stirring at room temperature, add 13 g of ammonium persulfate to 3 parts of water.
The solution dissolved in 0 ml was added dropwise over 1 hour. After stirring for 2 hours, 200 ml of water was added, and the precipitated crystals were separated by filtration. Recrystallize from acetonitrile to obtain 7.2 g of target dye M-1 (yield 6
3%). Other exemplified dyes could also be produced according to the synthesis method of Example 1.

Example (2) Synthesis of Dye (Synthesis of Exemplified Dye M-33) (Synthesis Scheme)

[0053]

[Chemical 13]

5.0 g of the coupler and 10 g of 3-methyl-4-amino-N, N-diethylaminobenzene were dissolved in 200 ml of methanol, and a solution of 15 g of potassium carbonate in 50 ml of water was added. While stirring at room temperature, add 13 g of ammonium persulfate to 3 parts of water.
The solution dissolved in 0 ml was added dropwise over 1 hour. After stirring for 2 hours, 200 ml of water was added, and the precipitated crystals were separated by filtration. Recrystallized from acetonitrile to obtain 7.8 g of the target dye M-33 (yield 6
5%). Other exemplified dyes could be produced according to the synthesis method of Example 2.

Example (3) Preparation of Thermal Transfer Material and Image Evaluation-Preparation of Ink-The following raw materials were mixed to obtain an ink of a uniform solution containing the dye according to the present invention.

Dye (M-1) ・ ・ ・ ・ ・ ・ 3.5g Polyvinyl butyral resin (BL-1, manufactured by Sekisui Chemical Co., Ltd.) ・ 6g Methyl ethyl ketone ・ ・ ・・ ・ ・ 200 ml-Preparation of heat-sensitive transfer material-The coating amount after drying the above ink on a polyethylene terephthalate base with a thickness of 4.5 μm using a wire bar.
A heat-sensitive transfer material 1 was prepared by coating and drying so as to have a concentration of 0.8 g / m ² and forming a heat-sensitive transfer layer on a polyethylene phthalate film. On the back surface of the polyethylene terephthalate base, a silicone-modified urethane resin (SP-2105, made by Dainichiseika) is used as a sticking prevention layer.
A nitrocellulose layer containing is provided.

—Preparation of Image Receiving Material— A support having polyethylene laminated on both sides of paper (a polyethylene layer on one side contains a white pigment (TiO ₂ ) and a bluing agent)
Ester-modified silicone as an image-receiving layer (with an amount of 0.
A methyl ethyl ketone solution containing a polyester resin containing 15 g / m ² ) was applied so that the amount of the polyester resin applied was 5 g / m ² to obtain an image receiving material-1.

—Preparation of Thermal Transfer Image— The thermal transfer material 1 and the image receiving material 1 were respectively overlaid, a thermal head was applied from the back of the thermal transfer material, and image recording was performed under the following recording conditions. An excellent magenta image (Image-1) was obtained. (Recording conditions) Main scanning and sub scanning recording density: 8 dots / mm Recording power: 0.6 W / dot Heating time: The heating time is adjusted stepwise from 20 msec to 0.2 msec.

The evaluation results (maximum reflection density and light resistance) of the obtained images are shown below.

(Evaluation of maximum density) Maximum reflection density (Dmax)
Was measured using X-rite 310TR.

(Evaluation of light resistance) The image was irradiated with light with a xenon fade meter for 7 days, the density before irradiation was D0, and the density after irradiation was D, and (D / D0) × 100 (%) remained as dye. The light resistance was evaluated as a percentage.

Thermal transfer materials 2 to 7 and comparative thermal transfer materials 8 to 10 having the same structure as the thermal transfer material 1 were prepared except that the dyes of the thermal transfer material 1 were changed to the following dyes, and the same as above. Images (2-10) were created by the method. The results of the maximum reflection density and light resistance of the obtained image are shown below.
Incidentally, in the thermal transfer materials-8 to 10, the precipitation of the dye was observed due to the low solubility of the dye.

[0063] As described above, the heat-sensitive transfer material using the dye of the present invention improves the density and light resistance of the image formed with respect to the heat-sensitive transfer material using the comparative dye having a similar structure.

Further, the dye of the present invention is excellent in solubility and is also excellent in suitability for use as an ink for preparing a heat-sensitive transfer material, so that the sensitivity is greatly improved. Therefore, the dye of the present invention can exhibit excellent properties when used in an image forming material such as a heat-sensitive transfer material.

[0065]

The heat-sensitive transfer material containing the novel dye according to the present invention is excellent in various properties required for the dye for heat-transfer, particularly in solubility, sensitivity and light resistance.

Claims (2)

[Claims] 1. A thermal transfer material having a layer containing a dye on a support, wherein the dye has the following general formula (1) and / or
Alternatively, a heat-sensitive transfer material represented by the general formula (2). [Chemical 1] [In the formula, X represents an atomic group necessary for forming an aromatic ring condensed with a pyrazolone ring, and R ₁ represents a hydroxyl group, a salt of a hydroxyl group, or —N (R ₃ ) R ₄ . R ₂ represents a hydrogen atom or a monovalent group. n represents an integer of 0 to 3. R ₃ and R ₄ each independently represent a hydrogen atom, an alkyl group, an aralkyl group, a cycloalkyl group, an aryl group, or a heterocyclic group. Two
R ₂ , R ₃ and R ₄ , R ₂ and R ₃ , and R ₂ and R ₄ may be bonded to each other to form a ring. ] 2. A heat-sensitive transfer material having a layer containing a dye on a support, wherein the dye is represented by the following general formula (3). [Chemical 2] [In the formula, Y represents an atomic group necessary for forming an aromatic heterocycle condensed with a pyrazolone ring, and R ₅ represents a hydroxyl group, a salt of a hydroxyl group, or —N (R ₇ ) R ₈ . R ₆ represents a hydrogen atom or a monovalent group. m represents an integer of 0 to 4. R ₇ and R ₈ each independently represent a hydrogen atom, an alkyl group, an aralkyl group, a cycloalkyl group, an aryl group, or a heterocyclic group. Two R ₆ , R ₇ and R ₈ , R ₆ and R ₇ , and R ₆ and R
₈ may combine with each other to form a ring. ]