KR0177835B1 - Color element for sublimation thermal transfer printing - Google Patents

Abstract

Sublimation type heat transfer recording dye represented by the following general formula (I)

(In Formula (I), R <^1> is a hydrogen atom, a C1-C6 linear or branched alkyl group, a C5-C7 cycloalkyl group, R <^2> is a halogen atom, a hydroxyl group, an amino group, a cyano group, and a phenoxy. Derivatives, monoalkyl amine groups, dialkyl amine groups, linear or branched alkyl groups having 1 to 4 carbon atoms, alkoxy groups, acyl alkyl groups, aralkyl groups having 6 to 10 carbon atoms, and X is a hydrogen atom, a halogen atom or a cyano group , A linear or branched alkyl group having 1 to 6 carbon atoms, and Y and Z are oxygen atoms or dicyanomethylene groups.)

Description

Sublimation Pigment

The present invention relates to a dye for thermal transfer recording, and more particularly to a dye for sublimation thermal transfer recording.

Thermal transfer recording is not only widely used in office automation equipment such as facsimile machines and copiers, but has also recently been extended to print images that are electrically represented from color video cameras through video color printers. A sublimation thermal transfer method has been proposed.

The principle of a color printer is to separate images into yellow, magenta, and cyan colors by a color filter, and transfer them to a thermal element in the form of an electrical signal, whereby the applied energy is controlled by the thermal element, thereby transferring the dye sublimation transfer. The amount is transferred to the receiving layer of the recording material, and the process is repeated sequentially for Yerolwoo and Magenta cyan to induce a combination of three dyes corresponding to the desired color image.

The dye used in the sublimation type thermal transfer recording method,

1) Not easily sublimated and pyrolyzed under the operating conditions of the thermal recording head,

2) When the color is reproduced, the color is good,

3) The absorption coefficient of the molecule is large, and it should be able to react sensitively to the slight change of thermal transfer amount.

4) It should be stable against light, moisture, chemicals, etc., and have high durability.

5) The requirements must be easy to synthesize.

Conventionally, U.S. Patent Nos. 4,757,046, 4,695,287, 4,698,651, 4,701,439, 4,764,178, Japanese Patent Publication No. 59-78894, Japanese Patent Publication No. 59-227948, Japanese Patent Publication No. 60 -229789, Japanese Patent Application Laid-Open No. 61-268494, and Japanese Patent Application Laid-open No. 61-268495, etc., disclose various types of sublimation thermal transfer dyes, but they have insufficient durability and color sensitivity to meet the above requirements. Therefore, there is a need for the development of a more improved form of sublimation thermal transfer dye.

The present invention has been made to solve the above problems of the prior art, and an object of the present invention is to provide a sublimation type thermal recording dye having improved durability and color sensitivity.

In order to achieve the above object, the present invention provides a sublimation type thermal recording dye represented by the following general formula (I).

(Wherein R ¹ is a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 5 to 7 carbon atoms, R ² is a halogen base, a hydroxyl group, an amino group, a cyano group, a phenoxy derivative, mono An alkyl amine group, a dialkyl amine group, a linear or branched alkyl group having 1 to 4 carbon atoms, an alkoxy group, an acyl alkyl group, an aralkyl group having 6 to 10 carbon atoms, X is a hydrogen atom, a halogen atom, a cyano group and 1 carbon atom Or 6 linear or branched alkyl groups, Y and Z are oxygen atoms or dicyano methylene groups.)

Examples of the compound according to the present invention are as follows.

Among the compounds represented by the general formula (I) of the present invention, the color sensitivity was particularly good when R 1 is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms and R 2 is positioned at carbon 5 as a hydrogen atom or an alkylamino group. Among the compounds represented by the above general formula (I) as compounds which meet such requirements, (II), (III), (IV), (V), (VI), (X), (XIII) and (XIII) The compound represented by these is mentioned.

The compound of the present invention can be dispersed or dissolved in an organic solvent together with a binder to prepare an ink solution for thermal recording.

Binders that can be used with the compounds of the present invention, ethyl cellulose, hydroxy ethyl cellulose. Cellulose derivatives such as methylcellulose, cellulose acetate formate, cellulose acetate propionate, cellulose acetate butyrate, or vinyl resin derivatives such as polyvinyl alcohol, polyvinylacetate, polyvinyl butyral, polyacrylamide, or polyacrylate , Polymethyl methacrylate, polycarbonate, polysulfone, polyphenylene oxide and the like can be used.

Organic solvents used in the compounds of the present invention include methanol, ethanol, toluene, 2-butanone, cyclohexanone and N, N-dimethylformamide.

The heat transfer ink composition containing the compound of the present invention is represented by general formula (I)

2 to 10 parts by weight of a dye for thermal recording,

2 to 10 parts by weight of the binder and

80-96 parts by weight of organic solvent

It consists of.

In the thermal transfer ink composition, when the amount of the dye is 2 parts by weight or less, the concentration of the dye to be thermally transferred is low, resulting in poor recognition of the print. There is a problem of this deterioration.

The amount of the binder is preferably 2 to 10 parts by weight. If the amount is 2 parts by weight or less, the viscosity of the ink composition is lowered and the binding property is lowered, so that the dye may drop off when the ink composition is applied onto the substrate. If the amount is greater than 10 parts by weight, the viscosity of the ink composition is too high. Not only is it difficult to apply on the layer, there is a problem that the coating layer is also uneven.

It is preferable to apply | coat said thermal transfer ink composition on 0.4-2.0 micrometer thickness on the base material of thickness of 2-15 micrometers.

The substrate is polyester, polyamide, polyimide, polyacrylate. Polycarbonate, polyacetal, cellulose ester, or a film of a fluorine resin can be used, and preferably polyethylene terephthalate is preferable.

If the thickness of the substrate film is less than 2㎛, the substrate film is easy to be distorted when the substrate is in contact with the heat element of 400 ℃ high temperature is larger than 15㎛ there is a problem that the heat transfer is poor and the thermal transfer sensitivity is reduced.

The substrate to which the thermal transfer ink composition is to be applied can provide a heat resistant and release layer on the back side of the substrate film in order to facilitate the releasability between the thermal element and the substrate film and to prevent the substrate film from deforming upon contact with the thermal element. have.

Compounds used for this purpose include carboxylates, sulfonates, phosphates, aliphatic amine salts, polyoxyethylene alkyl esters, polyethylene glycerin fatty acid esters. Silicone oils and synthetic oils are used.

Polyacrylamide, polyisopropylacryl before application of the thermal transfer ink on the substrate to prevent the thermal transfer ink from reverse-transferring to the substrate and increase the sensitivity of the thermal transfer ink when the thermal ink composition is applied onto the substrate. It is preferable to form a hydrophilic polymer layer such as amide, butyl methacrylate, polyvinyl alcohol or polyvinylacetate on the substrate.

The thermal transfer recording material is composed of a thermal transfer sheet having a structure of a heat-resistant layer, a base film, a hydrophilic polymer layer, and a thermal transfer ink layer, and a dye-receiving layer and a recording base. It consists of a structure of a heat-resistant layer, a base film, a hydrophilic polymer layer, a thermal transfer ink layer, a dye receiving layer, and a recording base material, which are overlapped facing the dye receiving layer, between the thermal transfer ink layer of the thermal transfer sheet and the dye receiving layer of the recording sheet. Thermal transfer can occur to obtain an image on the recording sheet.

After the image is transferred onto the recording sheet, the thermal transfer sheet and the recording sheet are separated from each other.

As the base of the recording sheet, polyethylene terephthalate, polyester sulfone, polyamide, cellulose ester, polyester or white paper coated with white pigment is used.

As the dye receiving layer, polycarbonate, polyurethane, polyester, polyamide, polyvinyl chloride, styrene-acrylonitrile copolymer, polycaprolactam, or the like can be used.

Also, in order to smoothly separate the thermal transfer sheet and the recording sheet after thermal transfer, a release agent such as wax or silicone oil may be added to the dye receiving layer.

Next, a preferred embodiment of the present invention is presented.

However, the following examples are provided only for easy understanding of the present invention, and the present invention is not limited to these examples.

Example 1

[Synthesis process of pigment]

After dissolving 9.5 g of pyrrole-2-carboxyaldehyde and 14.6 g of 1.3-indandione in 200 ml of ethanol and refluxing for 6 hours, the reaction was carried out under reduced pressure and distilled under reduced pressure until 100 ml of ethanol remained in the reaction solution. After removing some, the filtrate was left at room temperature to form crystals.

The crystals thus formed were filtered, recrystallized with toluene, and dried to obtain 16.5 g of a compound of formula (II). (Mp 161 ° C., yield 74%).

[Manufacturing process of thermal transfer ink composition]

4 parts by weight of a compound of formula (II) synthesized by the above method

4 parts by weight of the binder

(Polybutyral resin, a brand name: BX-5, a manufacturer: Japanese semi-Yui)

Solvent (methyl ethyl ketone) 92 parts by weight

An ink composition was prepared by dissolving and dispersing the compound of Formula (II) and the binder forming the above composition in methyl ethyl ketone solvent at 50 ° C., followed by cooling.

[Manufacturing Process of Thermal Transfer Sheet]

The thermal transfer ink composition prepared above was applied to a polyethylene terephthalate film (manufacturer: Daejin Film (Japan), FB-1) having a thickness of one side that was heat-resistant, using a bar coder so that the dry coating amount was 1 g / m 2. After application it was dried.

[Manufacturing process of thermal transfer recording material]

The thermal transfer recording material was manufactured by superimposing the thermal transfer sheet produced by the above method so that the dye receiving paper (product name: upc3010, Sony Corporation, Japan) and the thermal transfer ink layer face the dye receiving layer.

EXAMPLES 2-9

The thermal transfer recording material was manufactured in the same manner as in Example 1 except that the thermal transfer dyes in Example 1 were used as the compounds of Formulas (III) to (IV), respectively.

Comparative Example 1

A thermal transfer recording material was prepared in the same manner as in Example 1 except that 1,4-diamino-2- (2'-chlorophenoxy) anthraquinone was used as the thermal transfer dye.

Comparative Example 2

A thermal transfer recording material was prepared in the same manner as in Example 1 except that 1,4-diamino-2- (2'-methylphenoxy) anthraquinone was used as the thermal transfer dye.

The color development sensitivity and durability of the thermal transfer recording materials prepared in Examples 1 to 9 and Comparative Examples 1 and 2 were evaluated by the following method, and the results are shown in the table.

[Assessment Methods]

1. Color sensitivity

Thermal recording device (manufacturer: Daechang Electric Co., Japan, model name: TH-FMR) The heat transfer recording material was passed through a thermal transfer recording material with a voltage of 22 volts and a heat capacity of 1.5 w / dot for the thermal head. Model name: TR 1224) was measured and evaluated the color development concentration.

2. Durable

35 ° ± 2 ℃, 60 ± 2% relative to xenon wedometer (manufacturer: Atlas, model name: ES-25 2500W) using xenon wedometer (manufacturer: Atlas, model name: ES-25 2500W) The decrease in image density before and after the evaluation was evaluated for 48 hours under the condition of humidity.

As shown in the above table, when the dye of the compound represented by the general formula (I) according to the present invention is used in the thermal transfer ink, the color concentration is 2-3 times higher than the conventional sublimation type thermal transfer dye, and the durability is 2 to 3. 4 times improvement.

Claims (5)

Sublimation type heat transfer recording dye represented by the following general formula (I). (In Formula (I), R <^1> is a hydrogen atom, a C1-C6 linear or branched alkyl group, a C5-C7 cycloalkyl group, R <^2> is a halogen atom, a hydroxyl group, an amino group, a cyano group, and a phenoxy. Derivatives, monoalkyl amine groups, dialkyl amine groups, linear or branched alkyl groups having 1 to 4 carbon atoms, alkoxy groups, acyl alkyl groups, aralkyl groups having 6 to 10 carbon atoms, and X is a hydrogen atom, a halogen atom or a cyano group , A linear or branched alkyl group having 1 to 6 carbon atoms, Y and Z are oxygen atoms or dicyano methylene groups.) The dye for sublimation thermal transfer recording according to claim 1, wherein R ¹ is selected from the group consisting of a hydrogen atom and an alkyl group having 1 to 4 carbon atoms. The dye for sublimation thermal transfer recording according to claim 1, wherein X is selected from the group consisting of a hydrogen atom or a cyano group. The dye for sublimation thermal transfer recording according to claim 1, wherein R ² is located at carbon 5 of pyrroring. An ink composition for sublimation thermal transfer recording, comprising 2 to 10 parts by weight of a compound represented by the general formula (I) of claim 1; 2 to 10 parts by weight of binder; 80 to 96 parts by weight of an organic solvent.