JPH051154B2 - - Google Patents

Description

[Detailed description of the invention]

Object of the Invention (a) Field of Industrial Application The present invention relates to a dye used in sublimation type heat-sensitive transfer recording and a heat-sensitive transfer recording sheet using the same. (b) Prior Art Conventionally, there has been a demand for technology for color recording facsimile printers, copying machines, television images, etc., and color recording technologies using electrophotography, 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. Thermal transfer methods include a melting method in which a transfer sheet with a heat-melting ink layer formed on a base film is heated by a heat-sensitive head to melt the ink and transfer recording 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 is heated by a thermal head to sublimate the dye, and then transferred and recorded onto a recording medium. Since the amount of sublimation transfer of the dye can be controlled by changing the applied energy, gradation recording becomes easy and is considered to be particularly advantageous for full color recording. (C) Problems to be Solved by the Invention The present invention has the following features: that it sublimates easily under the operating conditions of a thermal recording head, that it does not thermally decompose under the operating conditions of a thermal recording head, and that it has a favorable hue in terms of color reproduction; It has a large molecular extinction coefficient, is stable against light, moisture, and chemicals, and is easy to synthesize.
The object of the present invention is to provide a cyan dye that satisfies all of the following conditions: and excellent suitability for ink formation, and a thermal transfer recording sheet using the cyan dye. Structure of the invention (a) Means for solving the problem The present invention is based on the general formula [] (In the formula, X is a hydrogen atom, a methyl group, a formyl group,
represents an acetylamino group or a propionylamino group, Y represents a hydrogen atom, a methoxy group or an ethoxy group, R and R ¹ represent a hydrogen atom or a C ₁ to _{C 8} substituted or unsubstituted alkyl group, R ²
represents a hydrogen atom or a methyl group) and a heat-sensitive transfer recording sheet comprising a coloring material layer containing the dye on a base material. The dye of the present invention represented by the general formula [] is
For example, by using a known method, the following general formula [] (R ² is the same as defined above) Hydroxyquinolines represented by the following general formula [] (In the formula, X, Y, R and R ¹ are the same as defined above.) It is obtained by heating anilines represented by the following in the presence of silver nitrate. The thermal transfer recording sheet of the present invention using the dye of the present invention can be prepared by preparing an ink by dissolving or dispersing the dye in a medium together with a binder, and applying the ink onto a base film and drying it. It can be manufactured by Binders for ink preparation include water-soluble resins such as cellulose, acrylic acid, and starch, and organic solvents such as acrylic resin, methacrylic resin, polystyrene, polycarbonate, polysulfone, polyethersulfone, and ethyl cellulose. Examples include soluble resins. In the case of an organic solvent-soluble resin, it is possible to use it not only as an organic solvent solution but also in the form of an aqueous dispersion. In addition to water, media for ink preparation include alcohols such as methyl alcohol, isopropyl alcohol, and isobutyl alcohol, cellosolves such as methyl cellosolve and ethyl cellosolve, aromatics such as toluene, xylene, and chlorobenzene, ethyl acetate, Esters such as butyl acetate, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone, chlorinated solvents such as methylene chloride, chloroform, and trichloroethylene, tetrahydrofuran,
Examples include ethers such as dioxane, and organic solvents such as N,N-dimethylformamide and N-methylpyrrolidone. The base film used to apply ink for the production of transfer sheets includes condenser paper, thin paper such as glassine paper, polyester, polyamide,
Plastic films with good heat resistance such as polyimide are suitable, and their thickness may range from 3 to 50 .mu.m. The ink can be applied to the base film using a reverse roll coater, gravure coater, rod coater, air doctor coater, etc., and the thickness of the ink coating layer after drying is in the range of 0.1 to 5 μm. (Yuji Harasaki "Coating method" (1979))
Maki Shoten). Functions and Effects of the Invention Since the indophenol dye shown in [] above of the present invention has a clear cyan color, it is possible to obtain full-color recording with good color reproducibility by combining it with appropriate magenta and yellow colors. Furthermore, since it is easily sublimed 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 heat-sensitive head. Furthermore, since 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 a highly concentrated ink that is uniformly dissolved or dispersed.
By using these inks, it is possible to obtain a transfer sheet on which the dye is uniformly coated at a high concentration. Therefore, by using these transfer sheets, recording with good uniformity and color density can be obtained. EXAMPLES The present invention will be specifically explained below with reference to Examples, but these Examples are not intended to limit the present invention. Example 1 (a) Preparation of ink Above dye 10g Polysulfone resin ^* 10g Chlorobenzene 80g Total 100g *Manufactured by Nissan Chemical Industries, Ltd., Udel P-1700
(Product Name) A mixture having the above composition was treated with a paint conditioner for 10 minutes to prepare an ink.
The pigment and resin were completely dissolved, and an ink with a uniform solution could be obtained. (b) Production of transfer sheet Bar coater (RK Print Coat Instruments
The above ink was coated on a polyimide film (15 .mu.m thick) using a film manufactured by Co., Ltd., No. 1), and then air-dried to obtain a transfer sheet. (c) Transfer Recording The ink-applied surface of the transfer sheet was placed on the recording medium and recording was performed using a thermal head under the following conditions, and it was possible to obtain a clear cyan recording with a uniform color density of 1.25. Recording conditions: Main scanning and sub-scanning linear density: 4 dots/mm Recording power: 0.6 W/dot Head heating time: 10 msec The recording material is 34% by weight saturated polyester.
10 g of aqueous dispersion (manufactured by Toyobo Co., Ltd., Vylonal MD-1200, trade name) and silica (manufactured by Nippon Silica Kogyo Co., Ltd., Nipsil E220A, trade name)
Mix 1g of
Bar coater (RK Print Coat)
No. 3, manufactured by Instruments Inc., was applied and dried. Color density was measured using a densitometer RD-514 model (filter: Ratten No. 25) manufactured by Macbeth, USA.
Measured using A light resistance test of the obtained record was carried out using a carbon arc fade meter (manufactured by Suga Test Instruments Co., Ltd.) at a black panel temperature of 63±2°C, and there was almost no discoloration or fading after 40 hours of irradiation. The dye was produced as follows. Structural formula below 2.9g of 8-hydroxyquinoline represented by and the following structural formula Add 4.3g of the compound represented by to 150ml of ethanol and stir at room temperature, then add 3.4g of silver nitrate to 15ml of water.
ml of an aqueous solution was added dropwise. 15 ml of 28% ammonia water was added, and an aqueous solution of 10.5 g of silver nitrate dissolved in 10 ml of water was added dropwise, and the mixture was reacted at 30 to 40°C for 3 hours. After the reaction is completed, extract with chloroform,
After distilling off the solvent, column purification was performed using chloroform, and the following structural formula was obtained. Purified product of indophenol pigment represented by
5.1g was obtained. The above dye had a melting point of 158-160°C and a maximum absorption wavelength (chloroform) of 630 nm. Example 2 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 according to the method of Example 1. A cyan record with clear color density as shown in the table could be obtained.

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Claims (1)

[Claims] 1. General formula [] (In the formula, X is a hydrogen atom, a methyl group, a formyl group,
represents an acetylamino group or a propionylamino group, Y represents a hydrogen atom, a methoxy group or an ethoxy group, R and R ¹ represent a hydrogen atom or a C ₁ to _{C 8} substituted or unsubstituted alkyl group, R ²
represents a hydrogen atom or a methyl group) A dye for thermal transfer recording. 2. In the dye for thermal transfer recording according to claim 1, R and R ¹ are hydrogen atoms, C ₁ to _{C 8}
alkyl group, _C3 - _C8 alkoxyalkyl group,
A substance characterized by being represented by a _C2 to _C4 hydroxyalkyl group, β-cyanoethyl group, β-chloroethyl group, allyl group, or tetrahydrofurfuryl group. 3 Apply the following general formula on the base material [] (In the formula, X is a hydrogen atom, a methyl group, a formyl group,
represents an acetylamino group or a propionylamino group, Y represents a hydrogen atom, a methoxy group or an ethoxy group, R and R ¹ represent a hydrogen atom or a C ₁ to _{C 8} substituted or unsubstituted alkyl group, R ²
represents a hydrogen atom or a methyl group.