JPS63224993A - Thermal transfer material - Google Patents

Abstract

PURPOSE:To form a sharp image superior in shelf stability, by a method wherein a thermal transfer material is formed by applying a layer containing an indo- phenol dyestuff of cyan shown by a specific general formula on a transfer substrate. CONSTITUTION:A coating liquid is prepared by dissolving or dispersing a dyestuff shown by a formula I (R1 represents alkyl, aralkyl, and aryl, R2 represents hydrogen, alkyl, aralkyl, and aryl, R3, R4 represent alkyl, halogenoalkyl, alkoxyalkyl, hydroxyalkyl, and cyanoalkyl, and X represents hydrogen, halogen, methyl, and triphloromethyl) and a binder resin in a solvent. The coating liquid is applied on a transfer substrate, such as a coated paper and a plastic film, and dried to form a thermal transfer material.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a thermal transfer material used for sublimation type thermal transfer recording.

[Prior Art] Currently, color recording techniques such as inkjet and thermal transfer are being considered as methods for obtaining hard copies from televisions, CRT color displays, color facsimiles, magnetic cameras, and the like.

Among these methods, the image recording method using sublimation thermal transfer is a method in which an image is formed by sublimating the dye using heat, and the amount of sublimation transfer of the dye can be controlled by changing the energy applied to the thermal head. This method facilitates gradation recording and is attracting attention as an advantageous method for obtaining full-color hard copies.

By the way, anthraquinone dyes or indophenol dyes are currently used as cyan dyes for sublimation transfer, but either have insufficient sublimation properties or
The dissolution stability of the ink is poor, and the image is not transferred uniformly, resulting in uneven density, or excess dye develops in areas other than the image area that are not recorded, resulting in the so-called background smudge phenomenon. The disadvantage is that it reduces the overall quality.

[Problems to be Solved by the Invention] The present invention provides a heat-sensitive transfer material characterized by containing a cyan indophenol dye with good dissolution stability in an ink composition. The aim is to fundamentally resolve the issues of concern in this field.

[Means for Solving the Problems] The present invention relates to a heat-sensitive transfer material characterized by containing an indophenol dye represented by the following general formula.

[Example] As an indophenol dye, a method for producing one represented by the following structural formula is disclosed (Photogra
phic Sci, & Eng, to [4] 195 (
1961); Japanese Patent Application Laid-Open No. 50-100118).

The method for producing the dye of the present invention represented by the above general formula (1) is based on the description in the above literature, in which a compound represented by the following general formula and an aniline represented by the following general formula are mixed in the presence of an oxidizing agent. It can be produced by the following reaction.

Next, examples of the dye compound according to the present invention represented by the general formula (1) will be shown.

Compound Example m, p, 133-135℃; λmax (benzene) =
630nmm, p, 165-166℃; Input wax (benzea) = 643nmm, p, 178-180℃; Input m
ax (benzene) = 650nmλ engineering ax (benzene)
=636nm Input max (benzene) =636nm The sublimation transfer material is manufactured by applying a dye ink onto the transfer substrate. The transfer substrate may be any conventionally known material as long as it has a certain degree of heat resistance and strength.
For example, various processed papers, polyester films, polystyrene films, polypropylene films, and polycarbonate films.

Cellophane or these films have improved heat resistance and/or
0-dye ink that has been treated to improve smoothness is generally treated with a sublimable dye and a binder resin, and when using a laser as a heat source, a compound that absorbs the laser's oscillation wavelength is added. It consists of
It is manufactured by dissolving or atomizing it in a solvent using a ball mill or paint conditioner.

As the binder resin, any conventionally known binder resin can be used, and preferred examples include cellulose resins such as methylcellulose, ethylcellulose, hydroxyethylcellulose, ethylhydroxycellulose, and cellulose acetate, polyvinyl alcohol, polyvinyl acetate,
One or a mixture of two or more of vinyl resins such as polyvinyl butyral and polyvinylpyrrolidone are used.

Ethanol prononol is used as a solvent for dissolving or dispersing pigments, binder resins, etc.

Alcohols such as butanol and ethylene glycol monopropyl ether, acetone, methyl ethyl ketone,
Ketones such as methyl isobutyl ketone, aromatic solvents such as toluene, xylene, and chlorobenzene, chlorinated solvents such as dichloroethane, trichlorethylene, and perchlorethylene, and acetic acid esters such as ethyl acetate, butyl acetate, and nidoxyethyl acetate. One type or a mixture of two or more types may be used.

When preparing an ink composition for sublimation transfer using the dye of the present invention, it is preferable to select a binder resin and an ink solvent and use them in combination so that the ink remains completely dissolved.

The pigment ink obtained in this way can be coated with a bar coater,
A sublimation transfer material, which is a heat-sensitive transfer material, is manufactured by applying the dye onto a transfer substrate using a roll coater, knife coater, screen printing, gravure printing, or the like.

Printing paper can be paper coated with polyester resin or polyamide resin, synthetic paper such as polypropylene, polyvinyl chloride, or polyester, or treated to improve heat resistance on these synthetic papers, and then treated with dyes as necessary. A material coated with a highly compatible polyester resin, polyamide resin, etc. is used.

Example 1 Dye of Compound Example (1) 3 parts Polybutyral resin 4.5 parts Methyl ethyl ketone 46.5 parts Toluene
46 parts The above formulation was sufficiently dispersed and dissolved in a paint shaker, and then filtered through varnish filter paper to obtain an ink. The obtained ink was
No precipitate was observed even after storage for months.

Apply the above ink to a thickness of 1107 mm using a bar coater.
It was coated on condenser paper No. z and dried to obtain a sublimation transfer material. When this transfer body was placed opposite paper coated with polyethylene terephthalate resin and heated with a heating element, a clear cyan-colored image with high density and gradation corresponding to the applied energy was obtained on the paper.

The image storage stability (bleeding and discoloration) under high temperature and high humidity conditions was also good.

In place of the dye of Compound Example (1) in Example 1, the dyes of Compound Examples (2) to (8) were used, and the experiment was carried out in the same manner as in Example 1 in all respects. Almost the same good results as in Example 1 were obtained.

[Effects of the Invention] By using the cyan indophenol dye represented by the general formula [1] and having good dissolution stability, the heat-sensitive transfer material according to the present invention has advantages that have not been seen in the past. It is possible to obtain extremely clear images with excellent storage stability, and in this respect, the drawbacks of conventional heat-sensitive transfer materials can be completely eliminated, and the industrial applicability is great.

Claims (1)

[Claims] General formula▲ Numerical formula, chemical formula, table, etc.▼ [In the formula, R_1 is an alkyl group, aralkyl group, or aryl group, R_2 is hydrogen, an alkyl group, an aralkyl group, or an aryl group, R_3 and R_4 represents an alkyl group, a halogenoalkyl group, an alkoxyalkyl group, a hydroxyalkyl group, or a cyanoalkyl group, and X represents hydrogen, halogen, a methyl group, or a trifluoromethyl group. ] A heat-sensitive transfer material characterized by containing a dye represented by: