JPS60239291A - Coloring matter for thermal recording - Google Patents

Abstract

PURPOSE:To contrive enhancement of color reproduction property, heat resistance, molar absorptivity, preservation stability and ink-preparing property, by using a specified azo coloring matter as a coloring matter for sublimation-type thermal transfer recording. CONSTITUTION:An amine of formula II, wherein D is any of formulas IV-VI, is converted into a diazo compound, which is coupled with an aniline of formula III, wherein X is hydrogen, methyl, formyl, acetylamine group or the like, Y is hydrogen, methoxyl or ethoxyl, each of R and R<1> is hydrogen or subst. or unsubst. 1-8C alkyl, to obtain a cyan coloring matter of formula I. The coloring matter is dissolved or dispersed in a solvent together with a binder to prepare an ink, which is applied to a base such as a tissue paper and a heat-resistant film to produce a thermal transfer sheet. The coloring matter can be used in combination with an appropriate magenta color and an appropriate yellow color to obtain full color.

Description

DETAILED DESCRIPTION OF THE INVENTION OBJECTS OF THE INVENTION A) Field of Industrial Application The present invention relates to a dye used in sublimation type thermal transfer recording.

Conventional technology Traditionally, there has been a demand for color recording technology for facsimile printers, copying machines, television pictures, etc., and electrophotography,
Color recording technologies using inkjet, thermal transfer, etc. are being considered.

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.

The thermal transfer method includes a melting method in which a transfer sheet with a heat-melting ink layer formed on a base film is heated by a thermal head to melt the ink and transfer it onto a recording medium; There is a sublimation method in which a transfer sheet on which an ink layer containing a sublimable dye is formed on a base film is heated by a thermal head to sublimate the dye and transfer and record it onto a recording medium. Since the amount of sublimation transfer of the 4j7 dye can be controlled by changing the energy applied to the head, gradation recording is easy and it is considered to be particularly advantageous for full color recording.

C) Problems to be Solved by the Invention When the dye is applied to this recording method, the dye must satisfy the following conditions.

■ Easily sublimated 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.

■ High molecular extinction coefficient.

■ Stable against light, moisture, chemicals, etc.

■ Easy to synthesize.

■ Excellent suitability for ink production.

An object of the present invention is to provide a cyan dye that satisfies the above conditions.

Structure of the Invention A) Means for Solving Problems The present invention is based on the general formula (1) (wherein, X represents a hydrogen atom, a methyl group, a formyl group, an acetylamino group, or a propionylamino group, and yFi
Represents a hydrogen atom, a methoxy group, or a methoxy group, and R and R1 represent a hydrogen atom X-ray of 0. The gist thereof is a heat-sensitive recording dye represented by the following formula: ~Os represents a substituted or unsubstituted alkyl group.

The dye of the present invention represented by the above general formula (1) can be prepared, for example, by the following general formula (It) D -NH,...
・・・・・・・・・・・・(It) (wherein, D is the same as defined above) is diazotized, and the following general formula (1) (wherein, X, Y%R1 is the same as the above definition).

When applying the dye of the present invention to this recording method, the ink is prepared by dissolving or dispersing the dye in a medium together with a binder in the form of particles, and the ink is applied onto a base film, dried, and transferred. Create a sheet.

Binders for ink preparation include water-soluble resins such as cellulose, acrylic acid, and starch, and organic solvent-soluble resins such as acrylic resin, methacrylic resin, polystyrene, polycarbonate, polysulfone, polyethersulfone, and ethyl cellulose. Examples include resin. In the case of organic solvent-soluble resins, they can be used not only as an organic solvent solution but also in the form of an aqueous dispersion.

In addition to water, media for preparing ink include alcohols such as methyl alcohol, isobutyl alcohol, and isobutyl alcohol, cellosolves such as ethyl cellosolve and ethyl cellosolve, aromatics such as toluene, -xylene, and chlorobenzene, and ethyl acetate. , esters such as butyl acetate, acetone, methyl ethyl ketone, methyl imbutyl ketone, cyclohexalane natonoketones, methylene chloride, gastrointestinal chloride, chlorinated solvents such as trichloroethylene, ethers such as tetrahydro7rane, dioxane, N , N-dimethylformamide, N-
Organic solvents such as methylpyrrolidone may be mentioned.

Suitable base films for applying ink for making transfer sheets include thin paper such as condenser paper and glassine paper, and films made of plastics with good heat resistance such as polyester, polyamide, and polyimide.
Their thickness can range from 3 to j0 μm.

The method of applying the ink to the base film can be carried out using a Teha, reverse roll coater, Krachia coater, rod coater, air doctor coater, etc., and the thickness of the ink coating layer after drying is 0. 1~5μ
It is sufficient to apply the coating so that it covers the range of m (Yuji Harasaki, Maki Shoten, ``Coating Method'' 5, published in 1977).

Functions and Effects of the Invention Since the azo dye shown in the above (1) of the present invention has a clear cyan color, by combining it with appropriate magenta and yellow colors, full color recording with good color reproducibility can be achieved. Furthermore, since it sublimes easily 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, 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. Furthermore, since the dye of the present invention has good solubility in organic solvents and good dispersibility in water, it is easy to prepare highly concentrated ink that is uniformly dissolved or dispersed, and by using such ink. Therefore, a transfer sheet can be obtained which is coated with a dye uniformly and at a high concentration. Therefore, by using these transfer sheets, it is possible to obtain recordings with particularly good print uniformity and color density.

EXAMPLES The present invention will be explained in detail with reference to Examples below, but these Examples are not intended to limit the present invention.

Example 1 a) Preparation of ink N The above dye IO? Polysulfone resin *IO? Total 1ooi * Manufactured by Nissan Chemical Industries, Ltd., Needel P-/700
(Product Name) A mixture having the above composition was treated with a paint conditioner for 70 minutes to prepare an ink. The pigment and resin were completely dissolved, and an ink with a uniform solution could be obtained.

b) Preparation of transfer sheet The above ink was coated with a bar coater (RK Pr1ntcoa).
It was coated on a polyimide film (11 μm thick) using A/) manufactured by T Engineering Instruments, and then air-dried to obtain a transfer sheet.

C) Transfer recording The ink-applied surface of the above transfer sheet was placed on the recording medium and recorded using a thermal head under the following conditions, with a clear cyan color.
A record of uniform color density of -2 could be obtained.

Recording conditions Linear density of main scanning and sub-scanning Niged dot/11III+recording power: 0.6 W/dot head heating time: / (7 msec.

The recording medium was an aqueous dispersion of saturated polyester (manufactured by Toyobo Co., Ltd., Pyrotol MP-/2).
001 product name) IoT and silica (manufactured by Nippon Silikani Gyo Co., Ltd., N1psil K 2-2OA, product name) i
A bar coater (RE Pr1nt (! oatInstru
This product was manufactured by applying the product using a 3) manufactured by Ments Co., Ltd., and then drying it.

Color density was measured using a densitometer RD manufactured by Macbeth, USA.
-J/G type (filter: 2-Ten Juj).

A light resistance test of the obtained recording was carried out using a carbon arc fade meter (manufactured by Suga Test Instruments Co., Ltd.) (black panel temperature 63±2C), but there was almost no discoloration or fading after irradiation for ITO hours.

The dye used here was obtained by diazotizing 2-ami/-3-cyano-j-nitrothiophene with nitrosyl sulfuric acid and coupling it to N,IJ-cyzthyl-m-toluidine in acetic acid. Yes, the melting point is λlr! r-2t
The thick absorption value of the absorption spectrum of the chloroform solution at 7C was 42 I nm.

Example 1 The dyes shown in Table 1 were used instead of the dyes used in Example 1, and ink preparation, transfer sheet production, and transfer recording were carried out in the same manner as in Example 1. A clear cyan record with the color density shown in the table could be obtained.

Claims (2)

[Claims] (1) General formula (1) (wherein, X represents a hydrogen atom, methyl group, formyl group, acetylamino group or propionylamino group, Y represents a hydrogen atom, methoxy group or ethoxy group, R and R
1 is a hydrogen atom or 0. % Og of substituted or unsubstituted alkyl dyes. (2) % In the heat-sensitive recording dye according to claim 1, R and R1 are hydrogen atoms, C8-08 alkyl groups Cl-C8 alkoxyalkyl groups s Cm-Cs
alkoxyalkoxyalkyl group, C85-Oa acyloxyalkyl group, 01 to C8 alkoxycarbonylalkyl group, 0 to C6 hydroxyalkyl group,
A dye represented by a β-77noethyl group, a β-chloroethyl group, a β-phenoxyethyl group, a benzyl group, a β-7ethyl group, an allyl group, or a tetrahydrofurfuryl group.