JPH0530395B2 - - Google Patents

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 technologies using inkjet, thermal transfer, etc. are being considered as a method of 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 with heat, and the amount of sublimation transfer of the dye can be controlled by changing the energy applied to the heat-sensitive 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 both have insufficient sublimation properties or poor ink dissolution stability, making it difficult to transfer uniformly. This method has disadvantages in that it causes density unevenness in the image, or that excess dye develops in areas that are not recorded other than the image area, causing so-called background smearing, which deteriorates the quality of the entire image.

[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 open up the state of affairs in this world.

[Means for solving the problems] The present invention is based on the following general formula [Wherein, R ₁ is an alkyl group, an aralkyl group, or an aryl group, R ₂ is hydrogen, an alkyl group, an aralkyl group, or an aryl group, R ₃ and R ₄ are an alkyl group, a halogenoalkyl group, an alkoxyalkyl group, The hydroxyalkyl group or cyanoalkyl group, X represents hydrogen, halogen, methyl group or trifluoromethyl group. ] This relates to a heat-sensitive transfer material characterized by containing an indophenol dye represented by the following.

[Example] The indophenol dye has the following structural formula: [In the formula, R is OH or NHR ₅ (R ₅ represents an alkyl group or a phenyl group.) R ₃ and R ₄ are an alkyl group, a halogenoalkyl group, an alkoxyalkyl group, a hydroxyalkyl group, or a cyanoalkyl group. , X represents hydrogen, halogen, methyl group or trifluoromethyl group. ] A method for manufacturing the product represented by is disclosed (Photographic Sci. & Eng. 5 [4] 195 (1961);
(Japanese Patent Application Publication No. 50-100116).

As a method for producing the dye of the present invention represented by the above general formula [1], according to the description in the above literature, the following general formula [In the formula, R ₁ represents an alkyl group, an aralkyl group, or an aryl group, R ₂ represents hydrogen, an alkyl group, an aralkyl group, or an aryl group, and Y represents hydrogen or a halogen. ] A compound represented by and the following general formula [In the formula, R ₃ and R ₄ are an alkyl group, a halogenoalkyl group, an alkoxyalkyl group, a hydroxyalkyl group, or a cyanoalkyl group, and X is hydrogen,
Indicates halogen, methyl group or trifluoromethyl group. ] It can be produced by reacting the anilines represented by the following in the presence of an oxidizing agent.

Next, the dye compound according to the present invention represented by the general formula [1] will be shown.

Sublimation transfer bodies are manufactured by applying pigment ink onto a transfer substrate. As the transfer substrate, conventionally known
Any material may be used as long as it has a certain degree of heat resistance and strength, such as various processed papers, polyester films, polystyrene films, polypropylene films, polycarbonate films,
Cellophane or a film thereof that has been treated to improve heat resistance and/or smoothness is used. Pigment ink is generally composed of a sublimable pigment, a binder resin, and when using a laser as a heat source, a compound that absorbs the laser's oscillation wavelength. It is manufactured by dissolving or atomizing it.

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, and polyvinyl butyral. , a vinyl resin such as polyvinylpyrrolidone, or a mixture of two or more thereof.

Solvents for dissolving or dispersing pigments and binder resins include alcohols such as ethanol, propanol, butanol, and ethylene glycol monopropyl ether, ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone, toluene, xylene, and chlorobenzene. One or a mixture of two or more of aromatic solvents, chlorinated solvents such as dichloroethane, trichlorethylene, and verchlorethylene, and acetate esters such as ethyl acetate, butyl acetate, and ethoxyethyl acetate are 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 dye ink thus obtained is applied onto a transfer substrate using a bar coater, a roll coater, a knife coater, screen printing, gravure printing, etc. to produce a sublimation transfer body as a heat-sensitive transfer material.

Printing paper can be paper coated with polyester resin or polyamide resin, synthetic paper such as polypropylene, polyvinyl chloride, or polyester, or processed 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 Compound Example (1) Pigment 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 industrial filter paper to obtain an ink. Even when the obtained ink was stored at a temperature of 10° C. for one month, no precipitates were observed.

Apply the above ink to the thickness using a bar coater.
A 10 μm capacitor paper was applied and dried to obtain a sublimated object. When this subject 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 storage stability (bleeding and discoloration) of the image 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 rest was carried out in the same manner as in Example 1. Almost the same good results as in Example 1 were obtained.

[Effects of the Invention] The heat-sensitive transfer material according to the present invention uses a cyan indophenol dye represented by general formula [1] and has good dissolution stability, so that it 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] 1. General formula [Wherein, R ₁ is an alkyl group, an aralkyl group, or an aryl group, R ₂ is hydrogen, an alkyl group, an aralkyl group, or an aryl group, R ₃ and R ₄ are an alkyl group, a halogenoalkyl group, an alkoxyalkyl group, The hydroxyalkyl group or cyanoalkyl group, X represents hydrogen, halogen, methyl group or trifluoromethyl group. ] Characterized by containing a pigment represented by
Thermal transfer material.