JPH04275180A - Dye for thermal transfer recording - Google Patents

Abstract

PURPOSE:To enhance transfer properties, coloring properties and various fastnesses and to obtain a sharp cyan color by using a cyan dye represented by a specific chemical formula as the cyan dye for thermal transfer recording used in a sublimation type thermal transfer recording method. CONSTITUTION:A cyan dye for thermal transfer recording useful in a sublimation type thermal transfer recording system for taking a hard copy from the temporary image of a television, a video or a still video camera is represented by chemical formula (1) (wherein R1 and R2 are a substituted or non-substituted alkyl group or a cycloalkyl group, R3 is a hydrogen atom, a halogen atom, a cyano group or an alkyl group, R4 is a 3 to 5-membered cycloalkyl group which may have a substituent or a thienyl group bonded to a beta-position, R5 and R6 are a hydrogen atom, a halogen atom or a substituted or non-substituted alkyl group and X is a hydrogen atom or an atom or atom group forming 5- or 6-membered ring along with R1).

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to a cyan dye for thermal transfer recording, and more specifically, a vivid cyan dye with excellent transferability, colorability, and various fastness properties useful in a sublimation type thermal transfer recording method. The purpose is to provide

0002

2. Description of the Related Art Currently, one of the methods for obtaining hard copies from ephemeral images from televisions, videos, still video cameras, etc. is the sublimation type thermal transfer recording method. In this method, a dye is sublimated by heat to form an image on a recording medium, and a heating element or a semiconductor laser is used as a heat source. This method is considered to be especially advantageous for pictorial color recording because it is possible to control the amount of dye sublimation transfer by changing the energy applied to this heat source, and an image with good gradation can be obtained.

0003

[Problems to be Solved by the Invention] When a full-color image is obtained by the subtractive color method, the three primary colors that form the basis of hue expression are yellow, magenta, and cyan. Among these, cyan is a complementary color to red, is a clear blue-green color, and is required to have a maximum absorption wavelength of 620 to 680 nm. Cyan disperse dyes currently used for sublimation type thermal transfer recording lack chroma and cannot provide color images with excellent color reproducibility. Also, with recent advances in recording methods, there is a need for high-speed recording materials that can provide clear images with sufficient density at low energy consumption, but the disperse dyes currently used are not fully satisfactory in this respect. It does not have the same performance.

In view of these circumstances, the present invention was developed as a result of intensive research in order to solve the problems of the prior art.It was found that an indoaniline-based azomethine dye has extremely excellent transferability, exhibits a clear cyan color, and has a yellow color. It was discovered that when mixed with a dye and a magenta dye, it exhibits excellent color reproducibility, and the present invention was completed. That is, the gist of the present invention is a dye for thermal transfer recording represented by the following general formula (1).

[0005]

[Case 2]

In the formula, R1 is a substituted or unsubstituted alkyl group, cycloalkyl group, aralkyl group, or aryl group, or represents an atom or atomic group which together with X forms a 5- or 6-membered ring, R2 represents a substituted or unsubstituted alkyl group, cycloalkyl group, aralkyl group, or aryl group. Note that R1 and R2 may form a 5-membered ring or a 6-membered ring that may contain an oxygen atom or a nitrogen atom. R3 is a hydrogen atom, a halogen atom, a cyano group, an alkyl group which may have a substituent, a cycloalkyl group, an alkoxy group, an aralkyl group, an aryl group, an acyl group, an acylamino group, a sulfonylamino group, a ureido group, a carbamoyl group , represents a sulfamoyl group or an amino group. R4 represents a 3- to 5-membered cycloalkyl group which may have a substituent or a thienyl group bonded to the β position, and R5 and R6 may be the same or different, and each may be a hydrogen atom, a halogen atom, a substituted or unsubstituted Represents a substituted alkyl group, alkoxy group, acylamino group, sulfonylamino group, or ureido group. X is a hydrogen atom, or represents an atom or atomic group that forms a 5- or 6-membered ring together with R1, and n is 1
Or represents 2.

The dye represented by the general formula (1) can be produced by a known method, for example, by combining a compound represented by the general formula (A) and the general formula (B).
) p-phenylenediamine derivative represented by silver chloride,
It can be easily produced by oxidative coupling in alkaline conditions in the presence of an oxidizing agent such as ammonium persulfate or red blood salt.

[0008]

[C3]

The compound represented by general formula (A) can be obtained by a known method, for example, a method of dehydrochloric acid condensation of an aminophenol compound represented by general formula (C) and a carboxylic acid chloride compound represented by general formula (D). can be easily synthesized by

0010

[C4]

In the formula, Y represents a hydrogen atom or a halogen atom, and R1, R2, R3, R4, R5, R6
and X and n both have the above meanings. R1 in the general formula (1) is an alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group; a methoxyethyl group;
Alkoxyalkyl groups such as ethoxyethyl groups; hydroxyalkyl groups such as hydroxyethyl groups and β-hydroxypropyl groups; halogenoalkyl groups such as chloroethyl groups;
A cyanoalkyl group such as a cyanomethyl group or a cyanoethyl group; a cycloalkyl group such as a cyclohexyl group; an aralkyl group such as a benzyl group or a phenethyl group; an aryl group such as a phenyl group, tolyl group, halogenophenyl group, or alkoxyphenyl group; or together with X a 5-membered ring or a 6-membered ring
Examples include atoms forming member rings.

R2 is an alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group; a methoxyethyl group; an alkoxyalkyl group such as an ethoxyethyl group; a hydroxyalkyl group such as a hydroxyethyl group or a β-hydroxypropyl group; chloroethyl Halogenoalkyl groups such as groups; cyanoalkyl groups such as cyanomethyl group and cyanoethyl group; cycloalkyl groups such as cyclohexane group; aralkyl groups such as benzyl group and phenethyl group; phenyl group, tolyl group, halogenophenyl group, alkoxyphenyl group, etc. The following aryl groups are mentioned. Note that R1 and R2 may form a 5-membered ring or a 6-membered ring that may contain an oxygen atom, nitrogen atom, or sulfur atom.

R3 is a hydrogen atom; a halogen atom such as chlorine, bromine, or iodine; a cyano group; an alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group; an alkoxyalkyl group such as a methoxyethyl group or an ethoxyethyl group; Hydroxyalkyl groups such as hydroxyethyl group and β-hydroxypropyl group; Halogenoalkyl groups such as chloroethyl group; Cyanoalkyl groups such as cyanomethyl group and cyanoethyl group;
Cycloalkyl group such as cyclohexane group; methoxy group,
Alkoxy groups such as ethoxy, propoxy and butoxy groups; aralkyl groups such as benzyl and phenethyl; aryl groups such as phenyl, tolyl, halogenophenyl and alkoxyphenyl; acetyl, propanoyl and benzoyl groups, etc. Acyl group; Acylamino group such as acetylamino group, benzoylamino group; Sulfonylamino group such as methanesulfonylamino group, ethanesulfonylamino group, benzenesulfonylamino group; Methylureido group, 1,3-dimethylureido group, ethylureido group ureido groups such as groups; carbamoyl groups such as methylcarbamoyl group, ethylcarbamoyl group, phenylcarbamoyl group;
Examples include sulfamoyl groups such as methylsulfamoyl group, ethylsulfamoyl group, and phenylsulfamoyl group; amino groups such as methylamino group, ethylamino group, propylamino group, dimethylamino group, and diethylamino group. R4 represents a 3- to 5-membered cycloalkyl group such as a cyclopropyl group, 3-n-butylcyclobutyl group, or cyclopentyl group, or a thienyl group bonded to the β-position;
, R6 is hydrogen atom; halogen atom such as chlorine, bromine, iodine; methyl group; alkyl group such as ethyl group, propyl group, butyl group; alkoxyalkyl group such as methoxyethyl group, ethoxyethyl group; hydroxyethyl group, β - Hydroxyalkyl groups such as hydroxypropyl groups; Halogenoalkyl groups such as chloroethyl groups; Cyanoalkyl groups such as cyanomethyl and cyanoethyl groups; Alkoxy groups such as methoxy, ethoxy, propoxy, and butoxy groups; acetylamino groups, benzoyl Acylamino groups such as amino groups; sulfonylamino groups such as methanesulfonylamino groups, ethanesulfonylamino groups, benzenesulfonylamino groups; methylureido groups, 1,3-dimethylureido groups,
Examples include ureido groups such as ethylureido group. Preferred specific examples represented by the general formula (1) used in the present invention are shown in Table-1.

[0014]

[Table 1]

[0015]

[Table 2]

[0016]

[Table 3]

[0017]

[Table 4]

A method for producing a thermal transfer recording ink using the dye of the present invention includes a method in which the dye is dissolved or atomized using a ball mill or the like in a solvent together with a suitable binder to form an ink. Examples of the binder include epoxy resin, phenol resin, urethane resin, acrylic resin, silicone resin, cellulose resin, polyvinyl chloride, polyethylene, polystyrene, polycarbonate, polyester, polyimide, polyvinyl butyral, gum arabic, and casein. Examples of solvents include water, alcohols such as methanol, ethanol, propanol, and butanol, aromatic hydrocarbons such as toluene, xylene, and monochlorobenzene, ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone, dichloroethane, trichloroethylene, and perk. Examples include halogenated hydrocarbons such as oleethylene, esters such as ethyl acetate and butyl acetate, and cellosolves such as methyl cellosolve and ethyl cellosolve.

As a transfer method, the ink obtained above is coated onto a suitable substrate using a bar coater to create a transfer sheet, the sheet is overlapped with the recording medium, and then a heating element is inserted from the back side of the sheet. There is a method of heating the sheet with a heating device, etc., and by doing so, the dye on the sheet is transferred onto the recording medium. Generally, capacitor paper, cellophane paper, or a plastic film with good heat resistance such as polyimide resin or polyester resin is suitable as the transfer substrate. Plain paper can be used as the recording medium, but in order to increase color development sensitivity, paper coated with polyester resin or polyamide resin, or synthetic paper such as polypropylene, polyvinyl chloride, or polyester is used. be done. Since the dye of the present invention has a clear cyan color, for example, the dye has the following structural formula:

[0020]

[C5] The yellow dye represented by and the structural formula below

[0021]

It is suitable for obtaining full color in combination with the magenta dye represented by the following formula.

[0022]

According to the present invention, by using the indoaniline azomethine dye represented by the general formula (1) and having good transferability, a bright cyan-colored thermal transfer recording can be obtained.

[0023]

[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 (1) Production of dye 5 g of 2-cyclopropylcarbonylamino-4,6-dichloro-5-methylphenol was dissolved in 115 ml of acetone, and 8.2 g of sodium carbonate dissolved in 60 ml of water was added to this solution. and 5 g of 2-amino-5-diethyltoluene hydrochloride were added. Add 40% water to this mixture at room temperature while stirring.
ml of ammonium persulfate was added dropwise, and after the dropwise addition was completed, the reaction was allowed to proceed at room temperature for 1 hour. After the reaction is complete,
The precipitated crystals were filtered and recrystallized with toluene to obtain 6.4 g (yield: 83.0%) of the target indoaniline azomethine dye. The melting point was 182.5-182.7°C. The maximum absorption wavelength (ethyl acetate) of this product was 646 nm.

(2) Preparation of transfer sheet and transfer material After thoroughly kneading the ink composition of 3 parts of the dye obtained in (1) above, 7 parts of polyvinyl butyral resin, 45 parts of methyl ethyl ketone, and 45 parts of toluene using a ball mill. A transfer sheet of the present invention was obtained by coating a 6 μm thick polyethylene terephthalate film with a heat-resistant back surface with a bar coater so that the dry coating amount was 1.0 g/m 2 and drying.

Next, a coating solution containing 14 parts of polyester resin, 43 parts of methyl ethyl ketone, and 43 parts of toluene was added to
It was applied to synthetic paper as a base sheet at a rate of 0.0 g/m 2 and dried to obtain a transfer material.

(3) Transfer recording The above-mentioned transfer sheet of the present invention and the above-mentioned transfer material are faced to each other,
Recording was performed by heating the transfer sheet from the back side using a thermal head, and a clear cyan-colored, high-color-density record was obtained. The recording density (OD) was 1.95.

Examples 2 to 22 The dyes shown in Table 1 were synthesized in the same manner as in Example 1, and thermal transfer was carried out for each to obtain a clear cyan color record with high color density. The results of Examples 1 to 22 are shown in Table-5.

[0029]

[Table 5]

Claims (1)

[Claims] Claim 1: A dye for thermal transfer recording represented by the following general formula (1): [Formula 1] In the formula, R1 is a substituted or unsubstituted alkyl group, cycloalkyl group, aralkyl group, or aryl group, or It represents an atom or atomic group that forms a 5-membered ring or a 6-membered ring together with X, and R2 represents a substituted or unsubstituted alkyl group, cycloalkyl group, aralkyl group, or aryl group. In addition, R
1 and R2 may form a 5-membered ring or a 6-membered ring which may contain an oxygen atom or a nitrogen atom. R3 is a hydrogen atom, a halogen atom, a cyano group, an alkyl group which may have a substituent, a cycloalkyl group, an alkoxy group, an aralkyl group, an aryl group, an acyl group, an acylamino group, a sulfonylamino group, a ureido group, a carbamoyl group , represents a sulfamoyl group or an amino group. R4 represents a 3- to 5-membered cycloalkyl group that may have a substituent or a thienyl group bonded to the β-position, and R5 and R6 may each be the same or different and represent a hydrogen atom, a halogen atom, substituted or unsubstituted represents an alkyl group, alkoxy group, acylamino group, sulfonylamino group, or ureido group. X is a hydrogen atom or represents an atom or atomic group forming a 5-membered ring or a 6-membered ring together with R1, and n represents 1 or 2.