JPS61255897A - Coloring matter for recording - Google Patents

Abstract

PURPOSE:To obtain an ink for thermal transfer recording having good sublimation properties, small thermal decomposition properties and superior durability, by using a specific compound as the coloring matter in a composition of ink. CONSTITUTION:The compound shown by the formula is used as a coloring matter. In the formula, R and R' respectively designate an alkyl group, a cycloalkyl group, alkoxyalkyl group and an allyl group. As the alkyl group, a methyl group, an ethyl group, an n-propyl group, iso-propyl group or a straight chain or branched alkyl group having 4-10 carbons is used. As the cycloalkyl group, a cyclohexyl group, a cycloheptyl group or a cyclohexyl group for which 1-6 alkyl group(s) each having 1-6 carbon(s) is substituted is used. As the alkoxyalkyl, a methoxymethyl group, an ethoxyethyl group, a propyloxymethyl group, a butyloxymethyl group or a methoxyethyl group or the like is employed. For example, an ink for thermal transfer recording is produced by a method wherein the aforesaid coloring matter is mixed with an appropriate resin, solvent, water and the like.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is used for anthraquinone thermal transfer recording or complete sublimation jet recording. This invention relates to a new recording dye.

In more detail, there is a thermal transfer recording method in which the dye is sublimated and transferred to the recording material by heating with a thermal head, and a complete sublimation jet method in which the dye is heated and sublimated and then sprayed onto the recording material to create a record. The purpose of the present invention is to provide a vivid cyan dye that has high tinting power, excellent sublimation properties, stability, and light resistance, and is used in recording systems.

Conventional ' and 1 problemCurrently, there are two methods of obtaining color hard copies from televisions, CRT color displays, color facsimiles, magnetic cameras, computer outputs, etc., such as thermal transfer recording method or full field electric jet recording method. is being considered.

Normally, for example, in thermal transfer recording methods, there are two methods: a melt transfer method that combines a heat-melting substance and a pigment, and a sublimation transfer method that uses a transfer sheet coated with a sublimable dye, but the problem with the former is that the binder The compatibility between the heat-melting substance and plain paper affects the transfer efficiency, so for plain paper with low smoothness, anthraquinone-based C,I Disperse Blue, which is used for transfer printing of polyester fibers, is recommended. 1.3. Dyes such as '5, 14, 19.60 are known, but dyes such as C, I Disperse Blue 1.3, 5, 14.19 have a shallower color tone than the so-called cyan color, so It was inappropriate to reproduce full color in combination with yellow and magenta.

Furthermore, C,I Disperse Blue 60 had the disadvantage that sufficient concentration could not be obtained due to its high sublimation temperature.

In order to solve these drawbacks, a naphthoquinone compound dye has been proposed as a cyan dye in JP-A-59-78894. However, this dye has poor thermal stability.
analysis at 210°C or melting at 143°C ± 4°C),
This was insufficient to obtain clear records.

Further, in the case of the complete sublimation jet recording method, as in the case of the above-mentioned method, a cyan dye having a low sublimation temperature and good thermal stability is not yet known.

Method for Solving the Problems Under the above circumstances, the present inventors investigated various recording dyes and found that the following general formula [wherein R and R' are respectively an alkyl group, a cycloalkyl group, an alkoxyalkyl group, Represents an allyl group. ] The present inventors have discovered that when the compound represented by 1 is used as a pigment in, for example, an ink composition for thermal transfer recording, it has good sublimation properties, low thermal decomposition properties, and excellent durability.

The alkyl group represented by R and R' in the above formula of the dye according to the present invention is a methyl group, ethyl group, n-propyl group, 1so-propyl group, or a linear or branched carbon number 4 to 10 group. The cycloalkyl group refers to a cyclohexyl group, a cyclohebutyl group, or a cyclohexyl group substituted with 1 to 6 alkyl groups having 1 to 6 carbon atoms, and the alkoxyalkyl group includes methoxy Methyl group, ethoxymethyl group, propyloxymethyl group, butyloxymethyl group, methoxyethyl group, ethoxyethyl group, prooxyethyl group, butyloxyethyl group, pentyloxyethyl group, hexyloxyethyl group, methoxypropyl group.

Ethoxypropyl group, propyloxypropyl group.

Examples include 2-methoxybutyl group.

A method for producing, for example, a thermal transfer recording ink using the dye of the present invention is to mix the dye with a suitable resin, solvent, water, etc. to prepare the recording ink. In addition, as a thermal transfer method, the ink obtained above is applied onto a suitable base material to create a transfer sheet, the sheet is placed on the recording medium, and then heated and pressed from the back side of the sheet with a thermal recording head. In this way, the dye on the sheet is transferred onto the recording medium.

The resin used for preparing the above ink may be those used in ordinary printing inks, such as rosin-based, phenol-based, xylene-based, petroleum-based, vinyl-based, polyamide-based,
Alkyd type, nitrocellulose type,
Oil-based resins such as alkyl celluloses, maleic acid-based, acrylic acid-based, casein, shellac,
Water-based resins such as glue can be used. In addition, as solvents for ink preparation, alcohols such as methanol, ethanol, propatool, and butamel, cellosolves such as methyl cellosolve and ethyl cellosolve, aromatics such as benzene, toluene, and xylene, ethyl acetate,
Esters such as butyl acetate, ketones such as acetone, methyl ethyl ketone, and cyclohexanone, hydrocarbons such as ligroin, cyclohexane, and kerosene, dimethylformamide, etc. can be used, but when using a water-based resin, water or water-based resins may be used. It is also possible to use a mixture of the above solvents.

Suitable substrates for applying ink include thin paper such as condenser paper and glassine paper, and films made of plastics with good heat resistance such as polyester, polyamide, and polyimide. In order to improve heat transfer efficiency to the dye, a thickness of about 5 to 50 μm is appropriate.

Ordinary paper can also be used as the recording medium, but in order to improve the color development of the dye, it may be coated or impregnated with a resin that has good compatibility with the dye, or it may be laminated with a resin film. Good recording can be achieved by using paper or special processed paper that has been treated with acetylation.

It is also possible to use films of various resins or synthetic papers made from them.

Furthermore, by heat-pressing and laminating, for example, a polyester film on the transfer recording surface after transfer recording, it is possible to improve the color development of the dye and to stabilize the recording during storage.

The cyan dye of the present invention has much better sublimation properties than the above-mentioned dye for polyester fiber transfer printing, so it has a large coloring power and can produce a practically sufficient color density without placing a large burden on the thermal recording head. Transfer recording is possible. Furthermore, since the dye of the present invention has a vivid cyan color, it is suitable for obtaining full color by combining with appropriate yellow and magenta dyes.

Furthermore, since the light resistance is very good, durable recording can be obtained.

The present invention will be specifically explained below with reference to Examples.

However, this example is not intended to limit the invention.

The following test was conducted using this dye.

B) Method for preparing thermal transfer recording ink: the above dye (A)
2! iEthylcellulose
811 An ink was prepared by mixing the pigment mixture having the above composition with a paint conditioner using glass beads for about 30 minutes.

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

c) Transfer recording method: The ink-coated surface of the transfer sheet was placed on high-quality paper whose surface was coated with polyester resin, and thermal transfer recording was performed using a thermal recording head having a roseaceta-type heating resistor density. The dyes were transferred at temperatures above 136°C.

2) Synthesis of dye Leuco-1,4,5,8-tetraoxyanthraquinone 12I, cyclohexylamine 16.2N.

26 g of 1ao-propyl alcohol, 60 g of water, and 0.8 I of hydrosulfide were mixed and reacted at 78°C for 2 hours.

Cooled to room temperature and filtered. The filter cake was treated in 10 l of nitrobesozene at 150°C for 2 hours.

The mixture was cooled to room temperature, drained into 300 ml of methanol, and filtered and washed to obtain dye 14& of the above formula CAI.

λmax of this dye (in chloroform) = 685 nm,
m-p250°C or higher.

(Example-2) Dye B below A test was conducted in the same manner as in Example-1 using the following.

It was ℃.

[Example-3] The following formula (Q The test was conducted in the same manner as in Example 1 using the dye.

Transfer initiation temperature 150'C λmax of dye C) (in chloroform) = 680 nm, 1 m-p 133.3-13
The temperature was 3.9°C.

[Examples 4 to 11] When the dyes shown in the table below were synthesized and tested, clear cyan-colored transfers were obtained.

4 -C2H40CH3-C2H40C3Hs(
iso)6 -CH3-C6Ht3(n)8
-C2H5-C2H5 9-CH3-cH3

Claims (1)

[Claims] The following general formula ▲ includes numerical formulas, chemical formulas, tables, etc. ▼ [In the general formula, R and R' each represent an alkyl group, a cycloalkyl group, an alkoxyalkyl group, or an allyl group. ] Recording dye shown by.