JPH0667673B2 - Cyan dye for thermal sublimation transfer recording - Google Patents

Description

TECHNICAL FIELD The present invention relates to a cyan dye for a thermal sublimation transfer recording method as a method for obtaining a color hard copy from a television, a CRT color display, a color facsimile, a magnetic camera and the like.

Problems to be Solved by the Prior Art and Invention As a cyan dye for thermal sublimation transfer recording, JP-A-59-
78894 has the following general formula (A) [In the formula, R and R ¹ represent a methyl group, an ethyl group, a linear or branched propyl group, or a butyl group. ] The dye of formula (A) is disclosed, but the dye of the general formula (A) has a drawback that it has poor light resistance, which is a drawback in terms of storage of information records.

Further, JP-A-60-131294 discloses the following general formula (B) [In the formula, R ¹ represents an alkyl group, R ² represents an alkenyl group,
Alkenyloxyalkyl group, alkoxyalkyl group,
It represents an alkoxyalkoxyalkyl group, a hydroxyalkyl group, a hydroxyalkoxyalkyl group or a hydroxyalkylthioalkyl group. ] The anthraquinone dye represented by
The energy required at the time of transfer was large and the cost of the machine increased, which was not preferable.

Means for Solving the Problems As a result of intensive studies, the present inventors have found a cyan dye having good light resistance, good storage stability and good sublimation transferability, and completed the present invention.

That is, the present invention has the following general formula (I) [In the formula (I), X represents a cyano group or a halogen atom, Y represents a hydrogen atom, a methyl group, or an acylamino group, R ¹ represents an alkyl group or an allyl group, and R ² represents an alkyl group. , An allyl group, a cyanoalkyl group and a phenylalkyl group, and R ³ represents an alkyl group or an alkoxy group. ] The azo compound shown by these is provided.

In the formula (I), the alkyl group represented by R ¹ , R ² or R ³ includes a linear or branched alkyl group having 1 to 6 carbon atoms, and an example of the cyanoalkyl group is a cyanomethyl group. ,
A cyanoethyl group and a cyanopropyl group are exemplified, and a phenyl-ethyl group and a benzyl group are exemplified as the phenylalkyl group, and a halogen atom is chlorine, bromine,
Examples include iodine. Examples of the acylamino group represented by Y include an acetylamino group and a propionylamino group. Examples of the alkoxy group represented by R ³ include methoxy group and ethoxy group.

The dye of formula (I) can be synthesized by a known method according to formula (I
I) [In the formula (II), X has the same meaning as in the formula (I). ]
The amine represented by the formula (III) [In the formula (III), R ¹ , R ² , R ³ and Y have the same meanings as in the formula (I). ] It is obtained by coupling with an amine represented by

As a method for producing a thermal transfer recording ink using the dye of the present invention, the dye may be mixed with an appropriate resin solvent, water or the like to prepare the recording ink. As a thermal transfer method, the ink obtained above is applied onto a suitable substrate to prepare a transfer sheet, the sheet is superposed on a recording medium, and then the back surface of the sheet is heated and pressed by a thermal recording head. A method may be mentioned, in which case the dye on the sheet is transferred onto the recording medium.

As the resin for preparing the above ink, those used in ordinary printing inks may be used, such as rosin-based, phenol-based, xylene-based, petroleum-based, polysulfone-based, vinyl-based, polyamide-based, alkyd-based, and nitrocellulose. Oil-based resins such as resins and alkyl celluloses, or aqueous resins such as maleic acid-based, acrylic acid-based, casein, shellac, and glue can be used. Further, as a solvent for ink preparation, alcohols such as methanol, ethanol, propanol, butanol, methyl cellosolve, cellosolves such as ethyl cellosolve, aromatics such as benzene, toluene, xylene, ethyl acetate,
Ester such as butyl acetate, acetone, methyl ethyl ketone, ketones such as cyclohexanone, ligroin, cyclohexane, hydrocarbons such as kerosene, dimethylformamide and the like can be used, but when using an aqueous resin, water or water and the above It is also possible to mix and use the above solvents.

Suitable substrates for applying ink are thin papers such as condenser paper and glassine paper, and films of plastics with good heat resistance such as polyester, polyamide and polyimide. A thickness of about 5 to 50 μm is suitable for improving heat transfer efficiency to the dye.

As the recording medium, plain paper can be used, but in order to improve the coloring of the dye, a resin having good compatibility with the dye, or a resin to which acidic fine particles such as silica gel are added is usually used. Paper coated, impregnated, resin film laminated,
By using a special processed paper that has been acetylated, good recording with excellent image stability under high temperature and high humidity can be performed. It is also possible to use films of various resins or synthetic papers made from them.

Further, after transfer recording, for example, a polyester film may be hot-pressed and laminated on the transfer recording surface to improve the coloring of the dye and to stabilize the storage of the recording.

Examples Hereinafter, the present invention will be specifically described with reference to Examples. However, "part" represents part by weight, and% represents% by weight.

Example-1 (i) Synthesis of dye 24 parts of 2-cyano-4-nitro6-bromoaniline
Diazotized with 50 parts of 30% nitrosyl sulfuric acid in a mixed solution of 100 parts of 100% sulfuric acid and 50 parts of glacial acetic acid. 3 to 500 parts water and 30 parts hydrochloric acid
26 parts of-(N, N-diethylamino) 4-methoxyacetanilide was dissolved and cooled to 0 ° C. The above diazotization reaction solution was added to the solution, and the solution was neutralized with PH4, filtered, washed with water, and dried to obtain 35 parts of the dye of the following formula. λmax (in chloroform) was 625 nm.

(Ii) Method of preparing ink The ink was prepared by mixing the dye mixture having the above composition with glass beads and mixing with a bain conditioner for about 30 minutes.

(Iii) Method for preparing transfer sheet The above ink was applied to capacitor paper (10 μm thick) using a gravure proofing machine (plate depth 30 μm).

(Iv) Method of preparing image-receiving paper 10 g of an aqueous dispersion of 34% by weight saturated polyester (manufactured by Toyobo Co., Ltd., Pyronal MD-1,200) and 10 g of silica gel (manufactured by Nippon Silica, Nipsil E200A) were mixed, and the prepared paint was used as a fine paper. Bar coater (RK Print
Coat Instruments Co. No. 1) was used for coating.

(V) Transfer recording method The ink application surface of the transfer sheet was overlaid on the image receiving paper paint application surface, and thermal transfer recording was performed using a thermal head having a heating resistor of 250 Ω at a density of 4 dots / mm to obtain a color density of 0.95.
A cyan record was obtained. At this time, 18V to the thermal head
Was applied for 6 ms.

The color density is the densitometer RD manufactured by Macbeth Co.
It was measured using a -514 type (filter: Ratten No. 58).

The color density was calculated by the following formula.

Color density = log ₁₀ (Io / I) Io: intensity of light reflected from a standard white reflector I: intensity of light reflected from the test object Also, the light resistance test of the obtained record was performed using a xenon fade meter (suga). It was carried out at a black panel temperature of 63 ± 2 ° C. by using a testing machine (manufactured by Tester Co., Ltd.), but it was hardly discolored by irradiation for 40 hours and the stability of the image under high temperature and high humidity was excellent.

In addition, there was no color transfer even when it was placed at 40 ° C for 100 hours on an unrecorded image receiving paper.

[Example-2] Instead of the dye used in Example 1, the following formula Using 2 g of the dye represented by the following method, an ink was prepared, a transfer sheet was prepared, an image-receiving paper was prepared and transfer recording was carried out in the same manner as in Example 1, and the cyan color having a color density of 0.9 had excellent light fastness, and high temperature and high temperature. A record excellent in stability under humidity was obtained.

The above dye was synthesized in the same manner as in Example 1 using 2-chloro-4-nitro-6-cyanoaniline and 3- (N, N-diallylamino) -4-methoxyacetanilide. λma
x (in chloroform) = 620 nm.

[Example-3] (i) Method for preparing ink The dye mixture having the above composition was mixed with a paint conditioner for about 30 minutes using glass beads to prepare an ink.

(Ii) Method for preparing transfer sheet Using the gravure proofing machine used in Example 1, the above ink was applied to glassine paper (10 μm thick).

(Iii) Transfer recording method The ink-coated surface of the transfer sheet was superposed on a high-quality paper laminated with a polyester film (thickness of 10 μm), and the first embodiment was carried out.
As a result of recording under the same conditions using the thermal recording head used in 1., a cyan color having a color density of 0.85 was excellent in light fastness and was also excellent in stability at high temperature and high humidity. The above dye was synthesized in the same manner as in Example 1 using 2-chloro-4-nitro-6-cyanoaniline and 3- (N, N-diallylamino) -4-ethoxypropionylanilide. λmax (in chloroform) = 623 nm.

[Example-4] Instead of the dye used in Example 1, the following formula was used. Using 2 g of the dye represented by the following method, the ink was adjusted, the transfer sheet was prepared, the image-receiving paper was prepared, and the transfer recording was carried out in the same manner as in Example 1 and the cyan color having a color density of 0.90 was excellent in light fastness and at high temperature. A record excellent in stability under high humidity was obtained.

The above dyes are 2,6-dicyano-4-nitroaniline and 3
It was synthesized in the same manner as in the dye of Example 1 using-(N-pentyl N-cyanoethylamino) -4-methoxyacetanilide.

λmax (in chloroform) = 620 nm.

[Example-5] Using 2 g of the dye shown in Table 1, an ink was adjusted, a transfer sheet and an image-receiving paper were prepared in the same manner as in Example 1, and then transfer recording was performed in the same manner as in Example 1. Conducted to obtain a cyan color record having the color density shown in Table 1.
All of these records were tested for light resistance in the same manner as in Example 1. As a result, the records showed almost no discoloration and excellent image stability under high temperature and high humidity.

Claims (1)

[Claims] 1. The following general formula [In the formula (I), X represents a cyano group or a halogen atom, Y represents hydrogen, a methyl group, or an acylamino group, R ¹ represents an alkyl group or an allyl group, and R ² represents an alkyl group, It represents an allyl group, a cyanoalkyl group or a phenylalkyl group, and R ³ represents an alkyl group or an alkoxy group. ] The azo dye for thermal sublimation transfer recording shown by these.