JPH0447637B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thiadiazole dye for thermal transfer recording. Currently, a dye sublimation thermal transfer recording method has been proposed as a method for obtaining color hard copies from televisions, CRT color displays, color facsimile machines, magnetic cameras, etc. In this method, a transfer sheet coated with a sublimable dye is heated with a heat-sensitive recording head to sublimate and transfer the dye to the recording medium to obtain color recording. Since the amount of sublimation can be controlled, it is easy to express gradation, and compared to other recording methods, it is especially advantageous for obtaining full-color hard copies. By the way, the dye used in this recording method must meet the following conditions. Easily sublimated under the operating conditions of a thermal recording head. Do not thermally decompose under the operating conditions of the thermal recording head. Must have a favorable hue in terms of color reproduction. High molecular extinction coefficient. Stable against light, moisture, chemicals, etc. Easy to synthesize. Conventionally, dyes for transfer printing of polyester fibers have been considered for this recording method, but none have met the above conditions and have been put to practical use, and solid recording with sufficient color density has not been obtained. Nakatsuta. The object of the present invention is to provide a magenta dye that satisfies the above-mentioned requirements for a dye used in the heat-sensitive recording method. That is, the present invention has the following general formula [] (In the formula, R, R ¹ and R ² represent an allyl group, a lower alkyl group or a lower alkoxyalkyl group, and
represents a methyl group, formylamino group, or acetylamino group, and Y represents a hydrogen atom or a lower alkoxy group. In the dye of the above general formula [], compounds in which R, R ¹ and R ² are allyl groups and lower alkyl groups, X is methyl groups and formylamino groups, and Y is hydrogen atoms and methoxy groups are particularly preferred. Here, lower means having 1 to 4 carbon atoms. Specific examples of the dyes of the present invention include the following. 2-Methylthio-5-{2'-methyl-4'-(N,N
-dimethylamino)-phenylazo}-1,3,4
-thiadiazole, 2-methylthio-5-{2'-methyl-4'-(N,N
-diethylamino)-phenylazo}-1,3,4
-thiadiazole, 2-methylthio-5-[2'-methyl-4'-{N,N
-di-(iso-propylamino}-phenylazo]-
1,3,4-thiadiazole, 2-methylthio-5-{2'-formylamino-4'
-(N,N-dimethylhumino)-phenylazo}-
1,3,4-thiadiazole, 2-ethylthio-5-{2'-formylamino-4'
-(N,N-diethylamino)-phenylazo}-
1,3,4-thiadiazole, 2-(n)-propylthio-5-{2'-formylamino-4'-(N,N-diethylamino-phenylazo}-1,3,4-thiadiazole, 2-(iso )-Propylthio-5-{2'-formylamino-4'-(N,N-diethylamino)-phenylazo}-1,3,4-thiadiazole, 2-(n)-butylthio-5-{2'-formyl Amino-4'-(N,N-diethylamino)-phenylazo}-1,3,4-thiadiazole, 2-(iso)-butylthio-5-{2'-formylamino-4'-(N,N-diethylamino) )-phenylazo}-1,3,4-thiadiazole, 2-(β'-methoxyethylthio)-5-{2'-formylamino-4'-(N,N-diethylamino)phenylazo}-1,3, 4-thiadiazole, 2-(γ'-methoxypropylthio)-5-{2'-
Formylamino-4'-(N,N-diethylamino)-
phenylazo}-1,3,4-thiadiazole, 2-methylthio-5-[2'-formylamino-4'
-{N,N-di-(β'-methoxyethylamino)}-
phenylazo]-1,3,4-thiadiazole, 2-methylthio-5-[2'-formylamino-4'
-{N,N-di-(γ'-methoxypropylamino)}
-phenylazo]-1,3,4-thiadiazole, 2-methylthio-5-{2'-acetylamino-4'
-(N,N-diethylamino)-phenylazo}-
1,3,4-thiadiazole, 2-methylthio-5-[2'-acetylamino-4'
-{N,N-di-(n)-propylamino}-phenylazo]-1,3,4-thiadiazole, 2-ethylthio-5-{2'-acetylamino-4'
-(N,N-diethylamino)-phenylazo}-
1,3,4-thiadiazole, 2-methylthio-5-{2'-methyl-4'-(N,N
-dimethylamino)-5-methoxyphenylazo}
-1,3,4-thiadiazole, 2-methylthio-5-{2'-methyl-4'-(N,N
-dimethylamino)-5-(n)-butoxyphenylazo}-1,3,4-thiadiazole, 2-methylthio-5-{2'-methyl-4'-(N,N
-diethylamino)-5-methoxyphenylazo}
-1,3,4-thiadiazole, 2-ethylthio-5-{2'-methyl-4'-(N,N
-diethylamino)-5-methoxyphenylazo}
-1,3,4-thiadiazole, 2-methylthio-5-{2'-formylamino-4'
-(N,N-dimethylamino)-5-methoxyphenylazo}-1,3,4-thiadiazole, 2-methylthio-5-{2'-formylamino-4'
-(N,N-diethylamino)-5-methoxyphenylazo}-1,3,4-thiadiazole, 2-methylthio-5-{2'-acetylamino-4'
-(N,N-dimethylamino)-5-methoxyphenylazo}-1,3,4-thiadiazole, 2-methylthio-5-{2'-acetylamino-4'
-(N,N-diethylamino)-5-methoxyphenylazo}-1,3,4-thiadiazole, 2-ethylthio-5-{2'-acetylamino-4'
-(N,N-diethylamino)-5-methoxyphenylazo}-1,3,4-thiadiazole, 2-methylthio-5-[2'-methyl-4'-{N,N
-di-(n)-butylamino}-phenylazo]-
1,3,4-thiadiazole, 2-allylthio-5-{2'-formylamino-4'
-(N,N-diethylamino)-phenylazo}-
1,3,4-thiadiazole, 2-allylthio-5-{2'-acetylamino-4'
-(N,N-diethylamino)-phenylazo}-
1,3,4-thiadiazole, 2-methylthio-5-{2'-methyl-4'-(N-allyl-N-ethylamino)-5'-methoxy-phenylazo}-1,3,4-thiadiazole. As a method for producing the dye of the present invention, for example, the following general formula [] 5-amino-1,3,4- (wherein R represents the same meaning as in the above general formula)
Thiadiazoles are diazotized according to a conventional method, and the following general formula [] (In the formula, X, Y, R ¹ and R ² are the above general formula []
It can be easily obtained by coupling to an aniline represented by (having the same meaning as in ). As a method for producing a thermal transfer recording ink using the dye of the present invention, the dye may be mixed with a suitable resin, solvent, water, etc. to prepare the recording ink. In the thermal transfer method, the ink obtained above is applied onto a suitable base material to create a transfer sheet, the sheet is placed on the recording medium, and then heated and pressed from the back side of the sheet using a thermal recording head. In this way, the dye on the sheet is transferred onto the recording medium. As a resin for adjusting the above ink,
Those used in ordinary printing inks may be used, such as oil-based resins such as rosin-based, phenol-based, xylene-based, petroleum-based, vinyl-based, polyamide-based, alkyd-based, nitrocellulose-based, alkyl cellulose, or maleic resins. Acid-based,
Water-based resins such as acrylic acid, casein, Sierra, and glue can be used. In addition, as a solvent for ink adjustment, methanol, ethanol,
Alcohols such as propanol and butanol,
Cellosolves such as methyl cellosolve and ethyl cellosolve, aromatics such as benzene, toluene and xylene, esters such as ethyl acetate and butyl acetate, ketones such as acetone, methyl ethyl ketone and cyclohexanone, hydrocarbons such as ligroin, cyclohexane and kerosene. When using an aqueous resin, water or a mixture of water and the above-mentioned solvents can be used. Substrates for applying ink include condenser paper, thin paper such as glassine paper, polyester,
A plastic film having good heat resistance such as polyamide or polyimide is suitable, and the thickness of these substrates is suitably about 5 to 50 .mu.m in order to improve the efficiency of heat transfer from the heat-sensitive recording head to the dye. Plain paper can also be used as the recording medium, but in order to improve the color development of the dye, it may be coated or impregnated with a resin that is compatible with the dye, or it may be laminated with a resin film. Good recording can be achieved by using paper or special processed paper that has been treated with acetylation.
It is also possible to use films of various resins or synthetic papers made from them. Furthermore, by hot-pressing and laminating, for example, a polyester film on the transfer recording surface after transfer recording, it is possible to improve the color development of the dye and to stabilize the recording during storage. Since the dye of the present invention has a clear magenta color, for example, the structural formula is as follows: The yellow pigment represented by and the structural formula below Suitable for obtaining full color in combination with cyan dye represented by The above yellow dye can be easily obtained by diazotizing aniline and N-methyl-3-cyano-4-methyl-6-hydroxy-2-pyridone. Further, the above cyan dye can be obtained by reacting 1-amino-2-carboxy-4-methylaminoanthraquinone with methanol in concentrated sulfuric acid. EXAMPLES The present invention will be specifically explained below with reference to Examples, but these Examples do not limit the present invention. Example 1 Method for adjusting ink for thermal transfer recording The above composition: 2g Ethylcellulose 8g Isopropanol 90g Total 100g The ink was prepared by mixing the pigment mixture having the above composition for about 30 minutes with a paint conditioner using glass beads. Method for creating a transfer sheet The above ink was applied to condenser paper (10 μm) using a gravure proofing machine (plate depth 30 μm). Method for making receiver paper: 10 g of an aqueous dispersion of 34% by weight saturated polyester (Vylonal MD-1,200 manufactured by Toyobo Co., Ltd.)
and 50 g of calcium bicarbonate (Maruo Calcium Seisaku Super 1,500) 50% by weight water slurry,
Apply the adjusted paint to high-quality paper (thickness 200 μm) using a bar coater (RK Print-Coat Instruments No.
5). Transfer recording method The ink-coated surface of the transfer sheet was placed on the paint-coated surface of the image-receiving paper, and thermal transfer recording was performed using a heat-sensitive head with a 250Ω heat-generating low antibody at a density of 4 dots/mm, magenta with a color density of 1.20. Obtained a color record. At this time, a voltage of 18V was applied to the heat-sensitive head for 6 milliseconds. The color density is measured using a Dentometer RD-514 model manufactured by Macbeth in the United States (filter: Ratten No. 58).
Measured using Color density was calculated using the following formula. Color density = log ₁₀ (Io/I) Io: Intensity of reflected light from the standard white reflector I: Intensity of reflected light from the test object In addition, the light resistance test of the obtained record was performed using a carbon arc fade meter. (manufactured by Suga Test Instruments Co., Ltd.) (black panel temperature 63±2℃)
There was almost no discoloration after 40 hours of irradiation. Example 2 Using 2g of the pigment shown in Table 1, ink adjustment, preparation of a transfer sheet and receiver paper, and transfer recording were carried out in the same manner as in Example 1, and magenta with the color density shown in Table 1 was obtained. Obtained a color record. All of these records were subjected to a light fastness test in the same manner as in Example 1, and the records showed almost no discoloration. 【table】

Claims (1)

[Claims] 1. General formula [] (In the formula, R, R ¹ and R ² represent an allyl group, a lower alkyl group or a lower alkoxyalkyl group, and
represents a methyl group, a formylamino group, or an acetylamino group, and Y represents a hydrogen atom or a lower alkoxy group.