KR950008183B1 - Thermal transfer-recording material by sublimation - Google Patents

Abstract

The compound (I, R = H, C1-4 straight or branch alkyl; M = H, methyl, ethyl, cyano; D = one of formular II, where R1,R2 = H, C1-6 straight or branch alkyl, hydroxyalkyl, haloalkyl, alkoxyalkyl; R3 = H, C1-6 straight or branch alkyl, alkoxy, halogen; R4, R5 = H, methyl, ethyl; R6, R7 = H, C1-3 alkyl, alkoxy; Y = O, dicyanomethylene) 2-10 wt.%, binder 2-10 wt.% and organic solvent 80-96 wt.% are used as the sublimation type coloring matter for heat transcrioption recording. The compound I improves the durability and the color forming sensitivity of transcription coloring matter.

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 also in the field of use for printing images that have been recently represented electrically from color video cameras or electrical images from computers through video color printers. As a result, the sublimation thermal transfer method has been proposed as a representative method.

The principle of the color printer is that the image is separated into yellow, magenta, and cyan color by the color filter, and the image is transferred to the thermal element in the form of an electrical signal. By controlling the transfer to the receiving layer of the recording material and repeating the process sequentially for yellow and magenta cyan to induce a combination of the three dyes corresponding to the desired color image.

The dye used in the sublimation type thermal transfer recording method is 1) not easily sublimated and thermally decomposed under the operating conditions of the thermal recording head, 2) the color should be good when reproducing color, and 3) the absorption coefficient of the molecule is large, It must be able to react sensitively to slight changes, and 4) it must be stable and durable against light, moisture, and chemicals, and 5) must be easy to synthesize.

Conventionally, U.S. Patent Nos. 4,757,046, 4,695,287, 4,698,651, 4,70 1,439, 4,764,178, Japanese Patent Publication No. 59-78894, Japanese Patent Publication No. 59-227948, Japanese Patent Although various types of sublimation thermal transfer dyes are disclosed in Japanese Patent Application Laid-Open No. 60-229789, Japanese Patent Application Laid-Open No. 61-268494, and Japanese Patent Application Laid-Open No. 61-268495, they have durability and color development sensitivity. Inadequately, it is necessary to develop a more improved form of the 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).

[Formula 1]

In the formula (I), R represents a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, and M represents a hydrogen atom, methyl, ethyl or cyano group. D corresponds to one of the following structural formulas.

[Formula 2]

Wherein R ₁ and R ₂ each represent a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, a hydroxyalkyl group, a haloalkyl group or an alkoxyalkyl group, and R ₃ represents a hydrogen atom, a straight chain having 1 to 6 carbon atoms or A branched alkyl group, alkoxy, or a halogen atom, R ₄ and R ₅ each represent a hydrogen atom, a methyl group or an ethyl group, a methyl group or an ethyl group, and R ₆ and R ₇ each represent a hydrogen atom and an alkyl group having 1 to 3 carbon atoms, respectively. Or an alkoxy group).

Y represents an oxygen atom, a dicyano methylene group or a group of one of the following general formulas.

[Formula 3]

(Herein, R ₈ represents methyl or ethyl group.)

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

[Formula 4]

[Formula 5]

[Formula 6]

[Formula 7]

[Formula 8]

[Formula 9]

[Formula 10]

[Formula 11]

[Formula 12]

[Formula 13]

[Formula 14]

[Formula 15]

[Formula 16]

[Formula 17]

[Formula 18]

[Formula 19]

[Formula 20]

[Formula 21]

[Formula 22]

[Formula 23]

Among the compounds represented by the general formula (I) of the present invention, the color sensitivity is particularly good when R ¹ and R ² are methyl or ethyl groups, and Y is a dicyano methylene group.

Among the compounds represented by the general formula (I) as the compound meeting the requirements, (1), (2), (3), (4), (5), (6), (7), and (8) And compounds represented by (9), (10), (11) and (12).

The compound of the present invention can be prepared by dispersing or dissolving in an organic solvent together with a binder to produce an ink solution for thermal recording.

Binders that can be used with the compounds of the present invention include cellulose derivatives such as ethyl cellulose, hydroxy ethyl cellulose, methyl cellulose, cellulose acetate formate, cellulose acetate propionate, cellulose acetate butylate, or polyvinyl alcohol, polyvinyl Vinyl resin derivatives such as acetate, polyvinyl butyral and polyacrylamide, or polyacrylates, polymethyl methacrylates, polycarbonates, polysulfones and polyphenylene oxides and the like.

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

Thermal transfer ink composition comprising a compound of the present invention

It consists of 2x10 weight part of dyes for thermal recording represented by general formula (I), 2x10 weight part of binders, an organic solvent, and 80x96 weight part.

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 2x10 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 to 0.4 * 2.0micrometer thickness on the base material of thickness 2 * 15micrometer.

As the substrate, a film of polyester, polyamide, polyimide, polyacrylate, polycarbonate, polyacetal, cellulose ester, or fluorine resin may be used. Preferably, polyethylene terephthalate is preferable.

If the thickness of the substrate film is less than 2㎛, the substrate is easy to be distorted when the substrate is in contact with the thermal 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 may provide a heat resistant and release layer on the back surface of the coating 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.

As the compound used for this purpose, carboxylate, sulfonate, phosphate, aliphatic amine salt, polyoxyethylene alkyl ester, polyethylene glycerine fatty acid ester, silicone oil, synthetic oil and the like are used.

Polyacrylamide, polyisopropylacryl before applying 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 includes a thermal transfer sheet having a heat-resistant-based film-hydrophilic polymer layer-thermal transfer ink layer structure, and a recording sheet having a structure of a dye receiving layer-recording substrate and a thermal transfer ink layer of the thermal transfer sheet. It consists of a structure of a heat-resistant layer-substrate film-hydrophilic polymer layer-thermal transfer ink layer-dye receiving layer-recording base material, which is overlapped facing the dye receiving layer of the pyroxylate, and is formed of the thermal transfer ink layer of the thermal transfer sheet and the recording sheet. Thermal transfer takes place between the dye receiving layers 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.

In addition, a mold release material such as wax, silicone oil, or the like may be added to the dye-receiving layer in order to smoothly separate the thermal transfer sheet and the recording sheet after thermal transfer.

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 9.9 g of 1-methyl-2-pyrrolidinone and 6.6 g of malononitrile in 25 ml of ethanol, 2 × 3 drops of piperidine were dropped, and the temperature was raised to 80 ° C. to reflux and stirred for 2 hours. After the reaction, 14.9 g of 4-dimethylamino benzaldehyde was added to the reaction solution, and the mixture was stirred under reflux for 4 hours to proceed in a continuous reaction. After the completion of the reaction, the reaction mixture was cooled to room temperature, yellow crystals were collected, filtered and washed, and dried to obtain 18.1 g of the compound of the general formula (I) (m. P 175 ° C, yield 65%).

[Production of Thermal Transfer Ink Composition]

Synthesized by the above method

4 parts by weight of a compound of formula (I)

4 parts by weight of binder

(Polybutyral resin, product name: BX-5, manufacturer: Sekiyu, Japan)

Solvent (methyl ethyl ketone) 92 parts by weight

An ink composition was prepared by dissolving and dispersing the compound of Formula (1) and the binder in a methyl ethyl ketone solvent at 50 ° C. in a composition ratio of.

[Manufacturing Process of Thermal Transfer Sheet]

A bar coater was used to apply the thermal transfer ink composition prepared above to a polyethylene terephthalate film (manufacturer: Daejin Film, Japan, trade name: FB-1) having a thickness of one side that was heat-resistant to 1 g / m 2. It was then applied and 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 (manufacturer: Sony Japan, product name: UPC 3010) and the thermal transfer ink layer face the dye receiving layer.

Example 2-12

A thermal transfer recording material was prepared in the same manner as in Example 1 except that the thermal transfer dyes in Example 1 were each used as the compounds of Formulas (2) to (12).

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 thermal transfer dye dye 1,4-diamino-2- (2'-methylphenoxy) anthraquinone was used.

The color development sensitivity and durability of the thermal transfer recording materials prepared in Examples 1-12 and Comparative Examples 1-2 were evaluated by the following methods, and the results are shown in (Table).

[Assessment Methods]

1. Color sensitivity

Thermal recording device (manufacturer: Daechang Electric (Japan), model name: TH-FMR) The heat transfer recording material is passed through a thermal transfer recording material with a voltage of 22 volts and a heat capacity of 1.5 w / dot. 4, model name TR 1224) by measuring the color development concentration.

2. Durable

The thermal recording material that formed the image on the thermal recording device was left to stand for 48 hours at 35 ± 2 ° C and 60 ± 2% relative humidity using a xenon wedometer (manufacturer: Atlas, model name: ES-25 2500W). The decrease in image density before the evaluation and after the elapsed time was evaluated.

TABLE 1

As shown in the above table, when the compound represented by the general formula (I) according to the present invention is used as a dye for the thermal transfer ink, the color concentration is 2∽3 times and the durability is 2 compared with the conventional sublimation type thermal transfer dye. It can be seen that the 4 times improvement.

Claims (4)

Sublimation type heat transfer recording dye represented by the following general formula (I). (In the formula (I), R represents a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, and M represents a hydrogen atom, methyl, ethyl or cyano group. D corresponds to one of the following structural formulas.) . Wherein R ₁ and R ₂ each represent a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, a hydroxyalkyl group, a haloalkyl group or an alkoxy alkyl group, and R ₂ represents a hydrogen atom, a straight chain having 1 to 6 carbon atoms or A branched alkyl group, alkoxy, or a halogen atom, R ₄ and R ₅ each represent a hydrogen atom, a methyl group or an ethyl group, and R ₆ and R ₇ each represent a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or an alkoxy group) . Y represents an oxygen atom, a dicyano methylene group or a group of one of the following general formulas. (Herein, R ₈ represents methyl or ethyl group.) The dye for sublimation thermal transfer recording according to claim 1, wherein the R ₁ and R ₂ groups are methyl or ethyl groups. The dye for sublimation thermal transfer recording according to claim 1, wherein the Y group is a dicyano methylene group. 2x10 parts by weight of a compound represented by the general formula (I); Binder 2x10 parts by weight; An ink composition for sublimation thermal transfer recording, comprising 80 parts by weight of an organic solvent.