JPS61227091A - Coloring matter of dicyanoimidazole series for thermal transfer recording - Google Patents

Abstract

PURPOSE:To perform recording with favorable uniformity and color density, by a method wherein a color of magenta is constituted by the specified coloring matter of the dicyanoimidazole series. CONSTITUTION:The coloring matter of magenta for thermal transfer recording is constituted by the coloring matter of the dicyanoimidazole series for thermal transfer recording shown by a general formula (I). The coloring matter is easily produced as described below. After being diazotized, the 2-amino-4,5-di cyanoimidazole shown by a general formula (II) is combined with a compound of the aniline group shown by a general formula (III) by coupling to obtain an azo compound shown by a general formula (IV), and the azo compound is reacted with a alkylating agent to produce the coloring matter. The ink, which is prepared by a method in which the coloring matter is taken into solu tion of dispersed in a fine particle form in the medium together with a binding agent, is applied on a base film and dried to make a transfer sheet.

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 thermal transfer recording.

Conventional technology Traditionally, there has been a demand for color recording technology for facsimile printers, copying machines, television pictures, etc., and electrophotography,
Color recording technologies using inkjet, thermal transfer, etc. are being considered.

The thermal transfer 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-meltable 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 with an ink layer containing a sublimable dye formed on the ilm is heated by a thermal head to sublimate the dye and transfer and record onto the recording medium.The sublimation method uses a thermal head. Since the amount of sublimation transfer of the dye can be controlled by changing the energy given to K, gradation recording becomes easier, and this 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 meet the following conditions.

■ Easily sublimated under the operating conditions of the thermal recording head.

■ Do not thermally decompose under the operating conditions of the llIc thermal recording head.

■ It must have a favorable hue in terms of color reproduction.

■ Large molecular extinction coefficient.

■ Stable against heat, light, moisture, chemicals, etc.

■ Easy to synthesize.

■ Excellent suitability for ink production.

An object of the present invention is to provide a magenta dye that satisfies all of the above conditions.

That is, the present invention provides the following general formula CI) (wherein R%R
1 and R2 are allyl groups, C1 to C@ alkyl groups
'3~C@ represents an alkoxyalkyl group, aralkyl group, or hydroxyalkyl group; s represents an alkoxycarbonylamino group of C1-C,l, and Y represents a hydrogen atom s'1-C4 alkoxy group, methyl group, or halogen atom). That is.

As a method for producing one of these dyes of the present invention, for example, Koaminoshen represented by the following structural formula (U)! -Dicyanoimidazole was diazotized according to a conventional method, and the following general formula (in the formula, X% Y
%R1 and R3 are the same as defined above) The following general formula (IV) obtained by coupling with an aniline represented by
The azo compound represented by the following general formula (V) t or CM
) R-Z ・・・・・・・・・(V)(RO)180
s "・" (M) (in the formula, 2 represents a Hanawa atom, a bromine atom, an iodine atom, and R is the same as the above definition)
It can be easily obtained by reacting the alkylating agent shown in

Specific examples of the dye of the present invention include those shown in Examples, but are not limited thereto.

Particularly preferably, in the general formula CI), R, Ill, R'' represent an alkyl group of 01 to C., and
is C! -C4 alkylcarbonylamino groups and Y is a hydrogen atom are included.

When applying the dye of the present invention to this recording method, an ink is prepared by dissolving the dye together with a binder in a medium or dispersing it in the form of fine particles, and the ink is applied onto a base film and dried to form a transfer sheet. It is necessary to create one.

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 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, the medium for the ink (v4Illf) is K.

Alcohols such as methyl alcohol, isopropyl alcohol, isobutyl alcohol, ethyl cellosolve,
Selones such as ethyl cellosolve, aromatics such as toluene, xylene, and chlorobenzene, esters such as ethyl acetate and butyl acetate, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone, methylene chloride, chloroform, and tricloethylene. Examples include chlorine-based solvents such as chlorine-based solvents such as tetrahydro7rane, ethers such as dioxane, and organic solvents such as N,N-dimethylformamide and N-methylpyrrolide.

As a base film for applying ink in the production of a transfer sheet, thin paper such as condenser paper or glassine paper, or a plastic film with good heat resistance such as polyester, polyamide, or polyimide is suitable.
Their thickness can range from 3 to jo μm.

The method of applying the ink to the base film can be carried out using a TEHA, reverse roll coater 1/UT'7S-ter, rod coater, air doctor coater, etc., and the thickness of the ink coating layer is determined by drying. 0 left. /-1μm
(Coating Method, written by Yuji Harasaki, published by Yoko Shoten in 1972).

Functions and Effects of the Invention Since the dicyanoimidazole dye shown in the above (1) of the present invention has a clear magenta color, full-color recording with good color reproducibility can be obtained by combining it with appropriate yellow and cyan colors. Furthermore, since it sublimes easily 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 thermal head. Furthermore, since it is stable against heat, light, moisture, chemicals, etc., it does not undergo thermal decomposition during transfer recording, and the obtained 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, recordings with good uniformity and color density can be obtained.

EXAMPLES The present invention will be specifically explained with reference to Examples below, but these Examples are not intended to limit the present invention.

Examples/a) Preparation of ink The above-mentioned dicyanoimidazole dye of the present invention IOT cellulose acetate 1 lot (manufactured by Daicel Chemical Co., Ltd., L-jO) Total ゝ 100? The mixture having the above composition was treated with a paint conditioner for 70 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 The above ink was coated with a bar coater (RKPrintCoat).
A transfer sheet was obtained by applying the coating onto a polyimide film (thickness: tr μm) using a polyimide film (4/) manufactured by Nstrumenta, followed by air drying.

C) Transfer recording The ink-coated surface of the above transfer sheet was overlapped with the recording medium and recorded using a thermal head under the following conditions, and a clear magenta color was recorded in 7.
It was possible to obtain a record with a uniform color density of 0.

Recording conditions Linear density of main scanning and sub-scanning: 4t dots/printing
Power: 0. ay/dot head heating time
: '(' m!16c The recording medium is an aqueous dispersion of saturated polyester 34c (manufactured by Toyobo Co., Ltd., Pyle MD-/200. trade name) iot
and silica (manufactured by Nippon Silikani Gyo Co., Ltd., Nipθi'
Iliλ-OA, trade name)/l was mixed and prepared, and the solution was coated on high-quality paper (200 μm thick) using a bar coater (RK Pr
1nt Coat instruments manufactured by AJ
) after coating and drying.

Color density was measured using a densitometer RD manufactured by Macbeth, USA.
-! /4! - type (filter: Wratten A jr).

A light resistance test of the obtained record was carried out using a carbon arc fade meter (manufactured by Suga Test Instruments Co., Ltd.) (black panel temperature 63±2°C), but after irradiation for 4 Io hours, the color changed and faded. There wasn't. Furthermore, the transfer sheet and the recording were stable against heat and moisture, and had excellent storage stability in the dark.

Example λ Ink was prepared, a transfer sheet was prepared, and transfer recording was performed in the same manner as in Example 1 using the dyes shown in Table 1 instead of the dyes used in Example 1. As a result, the results were as shown in Table 1. It was possible to obtain a clear magenta color record with the color density shown.

The results of the light fastness test of the obtained record and the dark storage stability test of the transfer sheet/record were good.

Example 3 Using the dicyanoimidazole dye of the present invention used in Example, the following composition dye was prepared.
10f ethyl cellulose (manufactured by Bercules)
10? total
A transfer sheet was prepared and transfer recording was performed in the same manner as in Example 1, except that the ink was prepared in 1oot. As a result, 1. A good record of storage stability and light fastness could be obtained with a chromaticity of 0.

Sender: Mitsubishi Chemical Industries, Ltd. Representative Patent Attorney Hase - (1 other person)

Claims (2)

[Claims] (1) General formula [I] ▲There are mathematical formulas, chemical formulas, tables, etc.▼... [I] (In the formula, R, R^1 and R^2 are allyl groups, C_1 to C
Represents an alkyl group of _8, an alkoxyalkyl group of C_3 to C_6, an aralkyl group, a hydroxyalkyl group,
X is methyl group, methoxy group, formylamino group, C_1
~C_3 alkylcarbonylamino group, C_1~C_
a dicyanoimidazole dye for thermal transfer recording represented by . (2) In the dicyanoimidazole dye for thermal transfer recording according to claim 1, R, R^1 and R^
2 represents an alkyl group of C_1 to C_6, and X represents C_1 to
C_4 represents an alkylcarbonylamino group, and Y
A dye in which is represented by a hydrogen atom.