JPH05237B2 - - 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 recording sheet. 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 When a dye is applied to this recording method, the dye must satisfy 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. Excellent ink suitability. 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 the problem The present invention is based on the general formula [] (In the formula, X represents a hydrogen atom, a methyl group, a formyl group, an acetylamino group, or a propionylamino group, Y represents a hydrogen atom, a methoxy group, or an ethoxy group, and R and R ¹ are a hydrogen atom or C ₁ to C ₈
represents a substituted or unsubstituted alkyl group, and D is

【formula】

[Formula] or

A heat-sensitive recording dye represented by [formula] and a heat-sensitive recording sheet using the same,
This is the summary. The dye of the present invention represented by the above general formula [] is
For example, an amine represented by the following general formula [] D-NH ₂ ... [] (wherein D is the same as defined above) is cyazotized by a known method to obtain the following general formula [] It can be produced by coupling to an aniline represented by the formula (wherein X, Y, and R ¹ are the same as defined above). 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 fine particles, and the ink is applied onto a base film and dried. Prepare a transfer 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 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 μm. The ink can be applied to the base film using a reverse roll coater, gravure coater, rod coater, air doctor coater, etc. The thickness of the ink coating layer after drying is in the range of 0.1 to 5 μm. (Coating method, written by Yuji Harasaki, published by Maki Shoten, 1979). Functions and Effects of the Invention The azo dye shown in [] above of the present invention has a clear cyan color, so by combining it with appropriate magenta and yellow colors, it is possible to obtain full-color recording with good color reproducibility. suitable for
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. Even more heat,
Since it is stable against 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 uniformly dissolved or dispersed ink with high concentration, and by using such ink, 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 (trade 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 Preparation of transfer sheet Apply the above ink using a bar coater (RK Print
Coat Instruments Co., Ltd. No. 1) was applied onto a polyimide film (thickness: 15 μm) and air-dried to obtain a transfer sheet. c. Transfer Recording The ink coated surface of the above transfer sheet was placed over 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 1.2. 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 MP-1200, trade name) and silica (manufactured by Nippon Silica Industries Co., Ltd., Nipsil E220A, trade name)
It was produced by mixing 1 g of the solution, applying it to high-quality paper (200 μm thick) using a bar coater (manufactured by RK Print Coat Instruments, No. 3), and drying it. 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 conducted using a carbon arc fade meter (manufactured by Suga Test Instruments Co., Ltd.) (black panel temperature 63±2°C), but there was almost no discoloration or fading after 40 hours of irradiation. The dye used here is 2-amino-3-
Cyano-5-nitrothiophene was diazotized with nitrosylsulfuric acid and N,N-diethyl-m-
It was obtained by coupling to toluidine, and its melting point was 265-267°C, and the maximum absorption value of the absorption spectrum of a chloroform solution was 628 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 in the same manner as in Example 1. A clear cyan record with the color density shown in the table could be obtained.

【table】

【table】

【table】

【table】

[Table] *Measured values in chloroform

Claims (1)

[Claims] 1. General formula [] (In the formula, X represents a hydrogen atom, a methyl group, a formyl group, an acetylamino group, or a propionylamino group, Y represents a hydrogen atom, a methoxy group, or an ethoxy group, and R and R ¹ are a hydrogen atom or C ₁ to C ₈
represents a substituted or unsubstituted alkyl group, and D represents [Formula] [Formula] or [Formula]). 2. In the heat-sensitive recording dye according to claim 1, R and R ¹ are a hydrogen atom, a C ₁ to C ₈ alkyl group, a C ₃ to _{C 8} alkoxyalkyl group, or a C ₅ to C 8 alkyl group.
_C8 alkoxyalkoxyalkyl group, _C3 to _C8
acyloxyalkyl group, _C3 to _C8 alkoxycarbonylalkyl group, _C2 to _C4 hydroxyalkyl group, β-cyanoethyl group, β-chloroethyl group, β-phenoxyethyl group, benzyl group,
A dye represented by a β-phenylethyl group, an allyl group, or a tetrahydrofurfuryl group. 3 General formula [] (In the formula, X represents a hydrogen atom, a methyl group, a formyl group, an acetylamino group, or a propionylamino group, Y represents a hydrogen atom, a methoxy group, or an ethoxy group, and R and R ¹ are a hydrogen atom or C ₁ to C ₈
A thermosensitive recording sheet characterized in that it uses a dye represented by the following formula (representing a substituted or unsubstituted alkyl group, and D represents [Formula], [Formula], or [Formula]).