JPH03256793A - Heat-sensitive transfer sheet and ink composition therefor - Google Patents

Abstract

PURPOSE:To satisfy all of the necessary conditions of a sublimable dye by providing a color material layer containing a specific water-insoluble thiazole azo dye. CONSTITUTION:A color material layer containing a water-insoluble thiazole azo dye represented by formula (wherein X is a hydrogen atom, a halogen atom, a lower alkyl group or a phenyl group, R<1> is a cyano group, an alkoxylcarbonyl group, a phenyl group, a phenylsulfonyl group or a benzoyl group and K is a residue of a coupling component) is provided. This thiazole azo dye can be obtained, for example, by diazotizing amino acid represented by formula (II) according to a known method and reacting the diazotized compound with a coupling component according to a known method to obtain a monoazo compound and reacting an active methylene compound with this compound according to a known method.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a thermal transfer sheet and an ink composition for a thermal transfer sheet used for thermal transfer recording, particularly sublimation type thermal transfer recording.

(Prior Art) Conventionally, color recording technologies using electrophotography, inkjet, thermal transfer, and the like have been studied for facsimiles, copying machines, printers, and the like.

The thermal transfer recording method is considered to be advantageous over other methods because the device is easy to maintain and operate, and the device and consumables are inexpensive.

Thermal transfer methods include a melting method in which a transfer sheet with a heat-fusible ink layer formed on a base film is heated by a thermal head to melt the ink and then transferred and recorded onto an image receptor; A transfer sheet on which a color material layer containing a sublimable dye is formed is heated with a thermal head to sublimate and transfer the dye from the transfer sheet to an image receptor by thermal diffusion, and transfer recording onto the image receptor.Sublimation However, the sublimation method can control the amount of dye transfer by changing the energy applied to the thermal head, making gradation recording easy and particularly advantageous for full-color recording.

In thermal transfer recording using the sublimation method, the sublimable dye used in the transfer sheet and the ink composition for the transfer sheet is extremely important as it has a significant impact on the speed of transfer recording, the image quality of the recorded material, and the storage stability. Yes, the following conditions must be met.

■ Easy sublimation and thermal diffusion under the operating conditions of the thermal recording head.

■Do not thermally decompose under the operating conditions of the thermal recording head.

■ It must have a favorable hue in terms of color reproduction.

■ Large molecular extinction coefficient.

■ Stable against heat, light, moisture, chemicals, etc.

■ Easy to synthesize.

■ Excellent suitability for ink production.

■ No safety and health problems.

Up to now, no dye has been found that satisfies all of the above conditions, and in particular cyan dyes have various drawbacks and no satisfactory dye has yet been found.

(Problems to be Solved by the Invention) An object of the present invention is to provide a thermal transfer sheet and an ink composition for a thermal transfer sheet, which are characterized by using a cyan dye that satisfies all of the above conditions.

(Means for Solving the Problems) The present invention provides the following - Mataki (I) (wherein, X represents a hydrogen atom, a halogen atom, a lower alkyl group or a phenyl group, and R1 represents a cyano group, an alkoxycarbonyl group, A heat-sensitive transfer sheet comprising a coloring material layer containing a water-insoluble thiazole azo dye represented by a phenyl group, a phenylsulfonyl group, or a benzoyl group, and K represents a residue of a coupling component; - The gist thereof is an ink composition for a thermal transfer sheet containing a thiazole azo dye represented by Mataki (I), a resin as a binder, and an organic solvent and/or water.

The present invention will be explained in detail below.

The thiazole azo dye represented by the above-mentioned -Matagi (I) used in the present invention can be produced by a known method.

For example, an amine represented by the following - Mataki (II) (wherein, X represents the same meaning as in the above-mentioned - Mataki (I)) is diazotized by a known method, and the following - Mataki ( III) The coupling component represented by H-K (III) (in the formula, K represents the same meaning as in the above-mentioned -Matagi (1)) is reacted by a known method to form the following -Matagi ( IV) (wherein X and K represent the same meanings as in the above-mentioned -Matagi (I)) was obtained, and then this compound was treated with the following -
It can be obtained by reacting an active methylene compound represented by Mataki (V) (in the formula, R represents the same meaning as in Mataki (I)) by a known method.

Preferred examples of the thiazole azo dye represented by Mataki (I) used in the present invention include the following Mataki (VI):
, (■), (■), and (IX).

(In the formula, X and R1 represent the same meanings as in the above-mentioned -Matagi (I), Y represents a hydrogen atom, a lower alkyl group, a substituted or unsubstituted alkoxy group, or a 2 represents a hydrogen atom, a lower alkyl group, a formylamino group, a substituted or unsubstituted alkylcarbonylamino group, a benzoylamino group, a substituted or unsubstituted alkoxycarbonylamino group, or a halogen atom,
R2 and R3 represent a hydrogen atom, a substituted or unsubstituted alkyl group, an allyl group, or a substituted or unsubstituted aryl group. (wherein, X, R1, R2 and R3 represent the above-mentioned -matagi (VI)
(in the formula, X, R1, R2 and R3 are the above-mentioned -matagi (VI)
, and R7 represents a hydrogen atom or a methyl group) - Mataki (VI), (■), (■) used in the present invention
As a specific example of the dye represented by (IX), -Matagi%
Examples include those in which the formulas % Y and 2 are as follows.

The alkyl group represented by R2 and R3 is C1-
Examples include C8 linear or branched alkyl groups, and examples of substituted alkyl groups include 2-hydroxyethyl group and 3-hydroxyethyl group.
Hydroxypropyl group, 4-hydroxybutyl group, 2-
Hydroxy-substituted alkyl groups such as hydroxy-propyl groups: carboxymethyl group, 2-carboxyethyl group, 3
- Carboxy-substituted alkyl groups such as carboxypropyl groups; cyano-substituted alkyl groups such as 2-cyanoethyl groups;
an amino-substituted alkyl group such as a 2-amino-ethyl group; 2
-Halogen-substituted alkyl groups such as -chloroethyl group, 3-chloropropyl group, 2-chloro-propyl group, 2.2.2-)lifluoroethyl group; phenyl-substituted alkyl group such as benzyl group, 2-phenylethyl group ; 2-methoxyethyl group, 2-ethoxyethyl group, 2-(n) propoxyethyl group, 2- (iso) propoxyethyl group, 2-(n) butoxyethyl group, 2- (iso) butoxyethyl group, 2 -(2-ethyl-hexyloxy)
Alkoxy-substituted alkyl groups such as ethyl group, 3-methoxypropyl group, 4-methoxybutyl group, 2-methoxypropyl group; 2-(2-methoxyethoxy)ethyl group, 2
-(2-ethoxyethoxy)ethyl group, 2- (2-(
n) propoxyethoxy)ethyl group, 2-(2-(is
o) Propoxyethoxy)ethyl group, 2- (2-(n
)butoxyethoxy)ethyl group, 2-(2-(iso)
Alkoxyalkoxy-substituted alkyl groups such as butoxyethoxy)ethyl group, 2-(2-(2-ethylhexyloxy)ethoxy)ethyl group; 2-acetyloxyethyl group, 2-propionyloxyethyl group, 2-(n)butylene Ryloxyethyl group, 2-(iso)butyryloxyethyl group, 2-trifluoroacetyloxyethyl group,
Acyloxy-substituted alkyl groups such as benzoyloxyethyl group; methoxycarbonylmethyl group, ethoxycarbonylmethyl group, (n) propoxycarbonylmethyl group, (iso) propoxycarbonylmethyl group, (n) butoxycarbonylmethyl group, (iso) butoxy Carbonylmethyl group, 2-ethylhexyloxycarbonylmethyl group, benzyloxycarbonylmethyl group, furfuryloxycarbonylmethyl group, 2-methoxycarbonylethyl group, 2-ethoxycarbonylethyl group, 2-(
n) Propoxycarbonylethyl group, 2- (iso)
Propoxycarbonylethyl group, 2-(n)butoxycarbonylethyl group, 2-(iso)butoxycarbonylethyl group, 2-(2-ethylhexyloxycarbonyl)ethyl group, 2-benzyloxycarbonylethyl group, 2-fluor An optionally substituted alkoxycarbonyl-substituted alkyl group such as furyloxycarbonylethyl group; 2-methoxycarbonyloxyethyl group, 2-ethoxycarbonyloxyethyl group, 2- (n) propoxycarbonyloxyethyl group, 2- ( iso) propoxycarbonyloxyethyl group, 2-(n)butoxycarbonyloxyethyl group, 2-(iso)butoxycarbonyloxyethyl group, 2-(2-ethylhexyloxycarbonyloxy)ethyl group, 2-benzyloxycarbonyl group Optionally substituted alkoxycarbonyloxy-substituted alkyl groups such as oxyethyl group and 2-furfuryloxycarbonyloxyethyl group; furfuryl group,
Examples include a heterocycle-substituted alkyl group such as a tetrahydrofurfuryl group.

Examples of the aryl group represented by R2 and R3 include a phenyl group or a phenyl group having a substituent such as fluorine or a fluorine atom, a base atom, a methyl group, or a methoxy group.

Particularly advantageous R2 and R3 are hydrogen atoms, C
1-C8 linear or branched alkyl group, 2-
Hydroxyethyl group, 2-cyanoethyl group, 2-chloroethyl group, benzyl group, 2-phenylethyl group, 2-
Examples include (C1-C4 alkoxy)ethyl group, 2-allyloxyethyl group, 2-benzyloxyethyl group, 2-acetyloxyethyl group, 2-(C1-C4 alkoxy)carbonyloxyethyl group, and allyl group.

The alkoxycarbonyl group represented by R1 is C1
Examples include those having a C8 linear or branched alkyl group.

Particularly advantageous R1 groups include cyano groups and C1-C
Examples include alkoxycarbonyl groups having 4 alkyl groups.

Examples of the halogen atom represented by X include a fluorine atom, a chlorine atom, and a bromine atom, and examples of the lower alkyl group include a C-C4 linear or branched alkyl group.

Particularly preferred examples of X include hydrogen atom, chlorine atom, methyl group and phenyl group.

Examples of the halogen atom represented by Y and 2 include a fluorine atom, a chlorine atom, and a bromine atom. The substituted or unsubstituted alkylcarbonylamino group represented by Z includes acetylamino group, propionylamino group, (n)
Examples include a butyrylamino group, an (iso)butyrylamino group, and a trifluoroacetylamino group. The substituted or unsubstituted alkoxycarbonylamino group represented by 2 includes methoxycarbonylamino group, ethoxycarbonylamino group, (n) propoxycarbonylamino group, (iso) propoxycarbonylamino group, (n
) butoxycarbonylamino group, (iso)butoxycarbonylamino group, furfuryloxycarbonylamino group, benzyloxycarbonylamino group, tetrahydrofurfuryloxycarbonylamino group, and the like. Examples of the alkoxy group represented by Y include methoxy group, ethoxy group, (n) propoxy group, (iso) propoxy group, (n) butoxy group, (iso) butoxy group, and 2-ethylhexyloxy group. The group may be substituted, such as 2-chloroethoxy group, 2-methoxyethoxy group, 2-ethoxyethoxy group, 2-(n)pro, boxyethoxy group, 2-(iso)propoxyethoxy group, 2-(n ) Butoxyethoxy group, 2- (
iso)butoxyethoxy group, 2-benzyloxyethoxy group, 2-furfuryloxyethoxy group, 2-tetrahydrofurfuryloxyethoxy group, furfuryloxy group, tetrahydrofurfuryloxy group, and the like. The lower alkyl group represented by 2 and Y is C1-
Examples include C4 linear or branched alkyl groups.

Particularly advantageous examples of Y include 01-C4 alkoxy groups, methyl groups, hydrogen atoms, fluorine atoms, and chlorine atoms; particularly advantageous examples of Z include C2-C4 alkylcarbonylamino groups, Examples include a fluoroacetylamino group, an 02-C5 alkoxycarbonylamino group, a methyl group, a formylamino group, a fluorine atom, and a chlorine atom.

More specific examples of the dyes represented by Mataki (VI), (■), (■), and (IX) are those shown in Table (1).

When forming a coloring material layer containing the above-mentioned dye in the thermal transfer sheet of the present invention, the method is not particularly limited, and usually the dye is dissolved or dispersed in the form of fine particles in a medium together with a binder. An ink is prepared, and the ink is applied onto a base film and dried to form a coloring material layer on the base film.

As a binder for ink preparation, a binder with good heat resistance is used to prevent heat fusion with the image receptor during transfer recording, but in particular a binder with a softening point and heat distortion temperature of 100°C or higher is used. is preferred.

Specifically, water-soluble resins such as cellulose, acrylic acid, and starch, acrylic resin, methacrylic resin, polystyrene, polycarbonate, polysulfone, As resin, polyether sulfone, polyvinyl butyral, polyester, and ethyl cellulose1. Examples include organic solvents such as acetylcellulose or water-soluble resins.

These resins may be selected as appropriate depending on the solvent used as a medium for preparing the ink, and any resin that dissolves or is uniformly fractionated in the solvent may be used.

The amount of these resins used is in the range of 1 to 40% by weight, preferably 5 to 30% by weight based on the total weight of the ink composition.

In addition to water, media for ink preparation include alcohols such as methyl alcohol, isopropyl alcohol, and isobutyl alcohol, cellosolves such as methyl cellosolve and ethyl cellosolve, aromatics such as toluene, xylene, and chlorobenzene, ethyl acetate, Esters such as butyl acetate, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone, chlorinated solvents such as methylene chloride, chloroform, and trichloroethylene, ethers such as tetrahydrofuran and dioxane, N, N-dimethylformamide, N- Examples include organic solvents such as methylpyrrolidone, which may be used alone or in combination with -C.

In addition to the above ingredients, the above ink also contains organic and inorganic non-sublimable fine particles, dispersants, antistatic agents, antiblocking agents, antifoaming agents, antioxidants, viscosity modifiers, and mold release agents. Agents etc. can be added.

Suitable base films for applying ink for making transfer sheets include thin paper such as condenser paper and glassine paper, and plastic films with good heat resistance such as polyester, polycarbonate, polyamide, polyimide, and polyaramid. , their thickness can range from 3 to 50 μm.

Among the above base films, polyethylene terephthalate film is particularly advantageous in view of mechanical strength, solvent resistance, economic efficiency, and the like. However, in some cases, polyethylene terephthalate film does not necessarily have sufficient heat resistance, and the running properties of the thermal head are insufficient. By providing a layer of synthetic resin, it is possible to use a thermal head with improved running performance.

The ink can be applied to the base film using a reverse roll coater, gravure coater, rod coater, air doctor coater, etc. The thickness of the ink coating layer is 0.1 to 5 pm after drying. (Yuji Harasaki, Maki Shoten 19)
``Coating method'' published in 1979).

On the other hand, an ink composition for a heat-sensitive transfer sheet, which is another object of the present invention, contains a cyan dye represented by the above-mentioned (I), a resin as a binder, and an organic solvent and l or water. This is what we are doing.

The details of the cyan dye are as described above.

Further, the binder is specifically selected from among the above-mentioned water-soluble or organic solvent-soluble resins, depending on the solvent.

Among the above-mentioned resins, those with a heat distortion temperature and/or softening point of 100
℃ or higher is particularly preferred. As the organic solvent, the above-mentioned solvents are used. In addition, other additives such as the above-mentioned non-sublimable fine particles, dispersants, antistatic agents, antiblocking agents, antifoaming agents, antioxidants, viscosity modifiers, and mold release agents may also be used.

Furthermore, in the ink composition of the present invention, the above-mentioned
) The amount of the pigment used is 1 to 30% by weight, preferably 3 to 20% by weight, based on the total weight of the ink.

In order to prepare the ink composition of the present invention, a mixed solution consisting of a pigment, a solvent, and a resin is placed in a suitable container equipped with a stirrer, heated as necessary, or additives are added, and the pigment is added. The pigment can be adjusted by dissolving it in a solvent, or by using a paint conditioner, ball mill, sand grind mill, etc., to uniformly disperse the pigment in the solvent by adding additives as necessary.

(Actions and effects of the invention) The above-mentioned crosspiece (I) used in the heat-sensitive transfer sheet of the invention
Since the thiazole azo dye shown in has a clear cyan color, it is suitable for obtaining full color records with good color reproducibility by combining with appropriate yellow and magenta colors. Because it is easily thermally diffused and has a large molecular extinction coefficient, it is possible to obtain high-speed recording with high color density without placing a large burden on the thermal head. Furthermore, since it is stable against heat, light, moisture, chemicals, etc., it does not undergo thermal decomposition during transfer recording, and the resulting recording has excellent storage stability, particularly in terms of light resistance. or,
Since the pigment has good solubility in organic solvents and dispersibility in water, it is easy to prepare a highly concentrated ink that is uniformly dissolved or dispersed, and by using such ink, the pigment can be uniformly dissolved or dispersed. A heat-sensitive transfer sheet coated with high concentration can be obtained. Therefore, by using these heat-sensitive transfer sheets, recording with good uniformity and color density can be obtained.

Furthermore, the heat-sensitive transfer sheet of the present invention can utilize not only a thermal head but also infrared rays, laser light, etc. as a heating means.

Further, the ink composition of the present invention can be coated on a current-carrying film that generates heat when energized, and used as a current-carrying thermal transfer sheet.

(Examples) Hereinafter, the present invention will be specifically explained with reference to Examples, but these Examples do not limit the present invention.

Example 1 a) Preparation of ink 1 b) Preparation of transfer sheet The above ink was applied to a polyethylene terephthalate film (61,
A transfer sheet was obtained by coating the film on a dry film thickness of 10 m) and drying it. In addition, the heat-resistant lubricity treatment of polyethylene terephthalate film is performed by applying the following cyan dye to the polyethylene terephthalate film.
5g (Dye from the above clothing (1) No. 1) Polysulfone resin rate 100g
Chlorobenzene 100g*
Product name: Newdel P-1700 (produced by Yasan Kagaku Kogyo Co., Ltd.) Heat distortion temperature (ASTMD -648) 175°C
The mixture having the above composition was treated with a paint conditioner for 10 minutes to prepare an ink.

8 parts by weight of a polycarbonate resin having a repeating structural unit shown by, 1 part by weight of a phosphate ester surfactant (
The test was carried out by applying a solution containing 91 parts by weight of toluene under the trade name NIBLYSURF A-208B (product of Daiichi Kogyo Seishi Co., Ltd.) and drying (0.5 pm in terms of dry film thickness).

C) Preparation of image receptor 10 parts of saturated polyester resin (product name: TP-220, product of Nippon Gokai Co., Ltd.), amine-modified silicone (
Product name: KF393, Shin-Etsu Chemical Co., Ltd. product) 0.
A solution consisting of 5 parts of methyl ethyl ketone, 15 parts of methyl ethyl ketone, and 15 parts of xylene was applied onto synthetic paper (product name: Yubo FPG 150, manufactured by Oji Yuka Co., Ltd.) with a wire bar, dried (dry film thickness: 5 Ijm), and further heated in an oven for 100 parts of xylene. Image receptors were prepared by heat treatment at °C for 30 minutes.

d) Transfer recording The ink-applied side of the above transfer sheet was placed on the recording medium and recorded using a thermal head under the following conditions, resulting in a clear cyan color as shown in Table (2).
It was possible to obtain a record of uniform color density as shown in the figure.

Recording conditions Main scanning and sub-scanning density: 6 dots)/mm recording
Heating time for electric crab 0.156W/dot head: 13 m5ec Color density was measured using a densitometer TR manufactured by Macbeth, USA.
Measurements were made using Model -927.

A light resistance test of the obtained records was conducted using a carbon arc fade meter (manufactured by Suga Test Instruments Co., Ltd.) (black panel temperature 63 ± 2°C). 2) shows the actual value of ΔE.

Furthermore, the transfer sheet and the recorded matter were stable against heat and moisture, and had excellent storage stability in the dark.

The thick absorption wavelength of the dye used in this example in acetone is shown in Table (2), and the melting point is 156.0°C.
Met.

Examples 2 to 21 Preparation of ink and transfer sheet in the same manner as in Example 1 using the pigments shown in Clothing (2) below among the pigments shown in Clothing (1) instead of the pigments used in Example 1. As a result of fabrication and transfer recording, it was possible to obtain clear cyan recordings with the color densities shown in Table 2, and the light resistance was also good as shown in Table (2).

Table (2) A Example 22 A transfer sheet was prepared and transfer recording was performed in the same manner as in Example 1, using the ink prepared by the following method instead of the ink used in Example 1. As a result, a clear cyan color was obtained. Color 1
．． 62 uniform color density records could be obtained. Further, the results of the light fastness test of the obtained recording and the dark storage stability test of the transfer sheet and the recording were both good.

Pigment As resin same as in Preparation Example 1 Toluene cyclohexanone Total 5 g 10 g 0 g 0 g 15 g **As resin, trade name Nidenka As-8 (Denki Kagaku Kogyo Co., Ltd. product) (Picat softening point (JISK +687
0) 105°C)

Claims (2)

[Claims] (1) There is a general formula (I) ▲mathematical formula, chemical formula, table, etc. on the base film▼(I) (In the formula, X represents a hydrogen atom, a halogen atom, a lower alkyl group, or a phenyl group, and R^1 It is characterized by having a coloring material layer containing a water-insoluble thiazole azo dye represented by a cyano group, an alkoxycarbonyl group, a phenyl group, a phenylsulfonyl group, or a benzoyl group, and K represents a residue of a coupling component. Heat-sensitive transfer sheet. (2) An ink composition for a thermal transfer sheet containing a thiazole azo dye represented by the general formula (I) according to claim (1), a resin as a binder, an organic solvent and 1 or water. .