JPH0482783A - Thermal transfer recording material and thermal transfer recording - Google Patents

Abstract

PURPOSE:To obtain a thermal transfer recording material, with long shelf life containing a yellow color, which enables visualization of an image with high density and long shelf life by adding a layer containing a specific yellow color to a support. CONSTITUTION:This thermal transfer recording material has a layer containing a yellow color expressed by formula [I] on a support. The thermal layer or thermally melting layer of the thermal transfer recording material is stacked over an image-receiving material. Then heat suited to image information is applied to the thermal transfer recording material and the yellow color is migrat ed from the thermal layer or the thermally melting layer to the image-receiving material and then is fixed there. Thus an image is formed on the image- receiving material. This thermal transfer recording material can obtain an image with high density and long shelf life as a specific thermal diffusion yellow color is added to the thermal layer or the thermally melting layer. In addition, the thermal transfer recording material itself also has long shelf life.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a thermal transfer recording material and a thermal transfer recording method, and more specifically, the present invention relates to a thermal transfer recording material and a thermal transfer recording method. New thermal transfer recording material,
The present invention also relates to a thermal transfer recording method capable of efficiently forming images using the recording material.

(However, R4 represents a hydrogen atom or an alkyl group. [Prior Art and Problems to be Solved by the Invention] Traditionally, color recording methods such as inkjet method, electrophotographic method, thermal transfer method, etc. have been used to obtain color hard copies. Various technologies are being considered, and among them, the thermal transfer method has advantages such as easy operation and maintenance, miniaturization of the device, low cost, and low running cost.

In this thermal transfer method, a transfer sheet (thermal transfer recording material) consisting of a heat-melt ink layer provided on a support is heated with a heat-sensitive head, and the ink is transferred from the heat-melt ink layer to the transfer sheet (image-receiving material). The transfer sheet, which has an ink layer containing a heat-diffusible dye (sublimable dye) on a support, is heated with a thermal head, and the heat-diffusible dye is transferred from the ink layer to the transfer sheet. There are two types of transfer: a thermal diffusion transfer method (sublimation transfer method), but the latter thermal diffusion transfer method can change the amount of dye transferred according to the thermal energy of the thermal head, and the image Since the gradation can be controlled, it is advantageous for full-color recording.

However, in the conventional thermal diffusion transfer method, the dye used in the thermal transfer recording material is important, and the color tone of this dye has a great influence on the speed of thermal transfer recording, image quality, storage stability of the image, etc.

It is desirable for this type of dye to satisfy the following conditions.

(a) Easily diffuses heat under thermal recording conditions (head temperature, heating time).

(b) It must have a favorable hue in terms of color reproduction.

(c) Do not thermally decompose at the heating temperature during recording.

(d) Good light resistance, heat resistance, moisture resistance, chemical resistance, etc.

(e) It has a large molar extinction coefficient.

(f) Easily added to thermal transfer recording materials.

(g) Easy to synthesize.

(h) Excellent suitability for ink production.

By the way, pyridone azo type dyes are used as yellow dyes for thermal transfer recording materials, as disclosed in Japanese Patent Application Laid-open Nos. 60-27,594 and 60-27,594.
0-152,56: No. 1, No. 61-12,393, No. 61-244.575, No. 1l-262,191, No. 1i2-290,583, No. 62-39,380
It has been disclosed in various publications such as No. 1, and has been put into practical use in some cases.

These dyes satisfy many of the above conditions, but despite their good sublimation properties, they have low solubility in the binder of thermal transfer recording materials and low coloring power for image-receiving materials, so they cannot be used under normal recording conditions. There are problems in that sufficient image density cannot be obtained, or even if sufficient density is obtained, the storage stability of one image is poor, and furthermore, the storage stability of the thermal transfer recording material itself is also poor.

The present invention has been made to solve the above problems.

The purpose of the present invention is to provide a heat-sensitive transfer recording material containing a yellow dye and having an excellent preservability, which can produce images with high density and excellent preservability, and to efficiently form images using the recording material. The purpose of the present invention is to provide a thermal transfer recording method that can be used.

[Means for solving the above problem] The present invention according to claim 1 for achieving the above object,
This is a heat-sensitive transfer recording material characterized by having a layer containing a yellow dye represented by the following general formula [I] on a support.

In addition, the present invention according to claim 2 provides an image-receiving material which is superimposed on the layer of a heat-sensitive transfer recording material having a layer containing a dye represented by the following general formula [I] on a support. This is a thermal transfer recording method characterized in that an image is formed on an image-receiving material by heating the dye according to image information and diffusing and transferring the dye to the image-receiving material side.

However, in the general formula [11], R1 is an alkyl group.

represents a cycloalkyl group, alkenyl group or aryl group, R2 and R represent an alkyl group which may be the same or different from each other, and X represents (where R4 represents a hydrogen atom or an alkyl group); , Y represents an alkyl group, an alkoxy group, a halogen atom or a hydrogen atom.

The present invention will be explained in more detail below.

R1 represents an alkyl group, a cycloalkyl group, an alkenyl group, or an aryl group, which may have a substituent.

The alkyl group mentioned above includes an alkyl group having 1 to 6 carbon atoms,
That is, methyl group, ethyl group, isopropyl group, n-butyl group, amyl group, n-hexyl group, etc. are preferable.

The cycloalkyl group is preferably a cycloalkyl group having 5 or 6 carbon atoms, such as a cyclopentyl group or a cyclohexyl group.

The above-mentioned alkenyl group is preferably an alkenyl group having 3 to 6 carbon atoms, and representative examples thereof include 2-propenyl group and 3-hexenyl group.

The above aryl group is preferably a phenyl group.

Examples of the substituents that R' may have include alkyl groups (for example, methyl group, ethyl group, trifluoromethyl group, etc.), aryl groups (for example, phenyl group, etc.), alkoxy groups (for example, methoxy group, ethoxy group, etc.). Such),
Examples include halogen atoms (for example, chlorine atoms, fluorine atoms, etc.).

The alkyl group represented by R2 and R3 is as follows:
Preferred are alkyl groups having 1 to 6 carbon atoms, ie, methyl, ethyl, n-propyl, amyl, n-butyl, n-hexyl, and the like.

R1 and R3 may be the same or different, and each may have a substituent.

Examples of substituents in this case include aryl groups (eg, phenyl groups, etc.), alkoxy groups (eg, methoxy groups, ethoxy groups, etc.), halogen atoms (eg, chlorine atoms, fluorine atoms, etc.).

(R4 represents a hydrogen atom or an alkyl group.

).

The above Y represents an alkyl group, an alkoxy group, a halogen atom or a hydrogen atom.

A specific representative example of the yellow dye represented by the general formula [I] is shown in FIG.

The yellow dye represented by the general formula [I], that is, the yellow dye according to the present invention, satisfies all of the above conditions, is a dye that has particularly excellent heat diffusivity and coloring power, and is highly concentrated and can be stored easily. A dye image with excellent quality can be obtained.

Note that "thermal diffusion" as used in the present invention means that when a thermal transfer recording material is heated, the dye substantially independently diffuses and/or in a gaseous, liquid or solid state depending on the thermal energy.
or transfer, and is substantially synonymous with what is known as "sublimation transfer" among those skilled in the art.

The yellow dye according to the present invention can be produced by a known method, for example, the method described in JP-A-60-27594.

The heat-sensitive transfer recording material of the present invention comprises a layer (hereinafter sometimes referred to as a heat-sensitive layer) containing a yellow dye represented by the above-mentioned pattern [I] provided on a support.

The content of the dye in the heat-sensitive layer is per support.
o, i~20g is preferred.

The heat-sensitive layer is prepared by preparing a paint for forming a heat-sensitive layer by dissolving or dispersing one or more of the pigments in a solvent together with a binder in the form of fine particles, and applying the paint onto a support as appropriate. It can be formed by drying.

The thickness of the heat-sensitive layer is preferably in the range of 0.1 to 5 pm in dry film thickness.

The binder includes water-soluble polymers such as cellulose, polyacrylic acid, polyvinyl alcohol, and polyvinylpyrrolidone, acrylic resin, methacrylic resin, polystyrene, polycarbonate, polysulfone, polyether sulfone, polyvinyl butyral, polyvinyl acetal, and nitrocellulose. , ethylcellulose, and the like.

These binders may be used not only by dissolving one or more of them in an organic solvent, but also by dispersing them in a latex form.

The amount of binder used is 0.1 m of support
~50g is preferred.

Solvents for preparing the paint include water, alcohols (e.g. ethanol, propatool), cellosolves (e.g. ethyl acetate), aromatics (e.g. toluene, xylene, chlorobenzene), ketones (e.g. acetone, methyl ethyl ketone). .

Ethers (e.g. tetrahydrofuran, dioxane)
, chlorinated solvents (eg, chloroform, trichlorethylene), and the like.

The support may be any material as long as it has good dimensional stability and can withstand the heat of the thermal head during recording, but thin paper such as condenser paper or glassine paper, heat-resistant material such as polyethylene terephthalate, or polyamide polycarbonate may be used as the support. Plastic films are preferably used.

The thickness of the support is preferably 2 to 30 pm, and the support may have a subbing layer for the purpose of improving adhesion to the binder and preventing transfer and dyeing of the dye to the support.

Furthermore, an anti-sticking layer may be provided on the back side of the support (the side opposite to the heat-sensitive layer) for the purpose of preventing the head from sticking to the support.

The heat-sensitive transfer recording material of the present invention has a heat-sensitive layer on which the heat-sensitive transfer recording material is coated.
It may have a heat-fusible layer containing a heat-fusible compound as described in Japanese Patent No. 1'06997.

As this heat-melting compound, a colorless or white compound having a melting point of 65 to 130°C is preferably used,
For example, waxes such as carnauba wax, beeswax, campli wax, higher fatty acids such as stearic acid and behenic acid,
Examples include alcohols such as xylitol, amides such as acetamide and benzamide, and ureas such as phenylurea and diethylurea.

Note that these heat-melting layers may contain polymers such as polyvinyl and lolidone, polyvinyl butyral, and saturated polyester, in order to improve dye retention.

According to the thermal transfer recording material of the present invention, it is possible to obtain a yellow dye image with gradation using one type of dye, as will be described later. A total of three layers, a cyan heat-sensitive layer containing a cyan heat-sensitive layer, a magenta heat-sensitive layer containing a magenta dye, and a yellow heat-sensitive layer containing a yellow dye according to the present invention, are sequentially and repeatedly coated on the same surface of a support. preferable.

Furthermore, a heat-sensitive layer containing a black image-forming substance may be added to the above three layers, so that a total of four layers are repeatedly coated on the same surface of the support.

In the heat-sensitive transfer recording method of the present invention, a heat-sensitive layer or a heat-fusible layer of a heat-sensitive transfer recording material and an image-receiving material are superimposed, heat is applied to the heat-sensitive transfer recording material according to image information, and the heat-sensitive layer or heat-fusible layer of a heat-sensitive transfer recording material is An image is formed on the image receiving material by transferring and fixing the yellow dye from the layer to the image receiving material.

According to such a thermal transfer recording method, a high-density color image can be efficiently obtained by using a thermal transfer recording material containing the dye according to the present invention.

Further, this thermal transfer recording method will be explained with reference to the drawings.

In FIG. 2(A), when the yellow dye is contained in the heat-sensitive layer 5 of the heat-sensitive transfer recording material 6 consisting of the support 4 and the heat-sensitive layer 5, this yellow dye is absorbed from the heating resistor of the thermal head 7, for example. It is diffused and transferred to the image-receiving material 3 by heat and is fixed in the image-receiving layer 2 on the support l.

In addition, in the case of FIG. 2 (b) using a heat-sensitive transfer recording material in which a heat-melting layer is laminated on a heat-sensitive layer, when the yellow dye is contained in the heat-sensitive layer 5, this yellow dye generates heat in the thermal head 7. The heat from the resistor diffuses and transfers to the heat-fusible layer 9, causing cohesive failure or interfacial peeling of part or all of the yellow dye-containing heat-fusible layer 9a, and transfer to the image-receiving material 3gI.

Further, even when the yellow dye is contained in the heat-fusible layer 9 from the beginning, an image is formed on the image-receiving material 3 side according to the same principle as shown in FIG. 2(b).

The image-receiving material used in the present invention generally uses paper, plastic film, or a paper-plastic film composite as a support, and forms an image-receiving layer thereon with polyester resin, polyvinyl chloride resin, vinyl chloride, and other monomers ( For example, a layer of one or more polymers such as a copolymer resin with vinyl acetate, polyvinyl butyral, polyvinylpyrrolidone, polycarbonate, etc. is formed.

Further, the support itself may be used as an image-receiving material.

The image-receiving layer may contain a basic compound and/or a mordant.

The basic compound is not particularly limited, whether inorganic or organic, and for example, calcium carbonate, sodium carbonate, sodium acetate, alkylamines, arylamines, etc. can be used.

In addition, as a mordant, a compound having a tertiary amino group,
Examples include compounds having a nitrogen-containing heterocyclic group, or compounds having these quaternary cation groups.

[Examples] - Next, the present invention will be specifically explained based on Examples, but the present invention is not limited thereto.

(Example 1) Preparation of a paint - The following raw materials were mixed to obtain a uniform solution paint containing a heat-diffusible yellow pigment.

Yellow dye Y-1 (see Figure 1)...10g Polyvinyl butyral resin...20g Methyl ethyl ketone...150ml Toluene...
...... 150 ml - Thermal transfer recording material - The above paint was applied onto a polyethylene terephthalate film (support) with a thickness of 5 Bm so that the amount of pigment attached was 0.8 g/m
” and dried to obtain a heat-sensitive transfer recording material.

Note that a nitrocellulose layer containing a silicone-modified urethane resin (manufactured by Dainichiseika Kaisha, Ltd., 5P-2105) is provided on the back surface of the polyethylene terephthalate film as an anti-sticking layer.

One image-receiving material, one synthetic paper with a thickness of 150 gm (manufactured by Tamago Yuka Co., Ltd., YUPO-
Amino-modified silicone oil (manufactured by Shin-Etsu Silicone Co., Ltd., KF-393) was applied as an image-receiving layer on FPG 150).
．． 08g/m2 and epoxy modified silicone oil (
Manufactured by Shin-Etsu Silicone Co., Ltd., X-22343) 0.08g
/m2 of vinyl chloride resin with an amount of 5 g/m2
” to obtain an image-receiving material.

- Image recording method - The above thermal transfer recording material and the above image receiving material are stacked so that the coated surface of the thermal transfer recording material and the image receiving surface of the image receiving material face each other, and the thermal head is inserted from the anti-sticking layer side of the thermal transfer recording material. The image was recorded by hitting the target.

Table 1 shows the measurement results of the maximum reflection density (D , , , ) of the obtained images.

Note that the recording conditions and measurement method are as shown below.

Linear density of main scanning and sub-scanning: 28 dots/mm Recording voltage: 0.5 W/dot head heating time: lSm5ec (applied energy approximately 11.2X
The heating time was adjusted stepwise between 10 J) and 0.2 msec (applied energy of about 1.12X 10-'J).

Maximum reflection density 2 Optical densitometer [Konica Corporation pc^-
The measurement was carried out using a model 65.

(Examples 2 to 8) Yellow dyes Y-2, Y-3, Y-5, Y-7, Y-8, Y-1 were used in place of yellow dye Y-1 used in Example 1.
A thermal transfer recording material and an image receiving material were prepared under the same conditions as in Example 1, except that 0 and Y-12 (see FIG. 1 for both) were used, and images were formed in the same manner. Table 1 shows the measurement results of the maximum reflection density of the obtained images.

(Comparative Example 1.2) In place of yellow dye Y-1 in Example 1, the following 2
A thermal transfer recording material and an image receiving material were prepared under the same conditions as in Example 1, except that comparative dyes A and B were used, respectively, and images were formed in the same manner.

Table 1 shows the measurement results of the maximum reflection density of the obtained images.

Comparative Dye A: Comparative Dye B・ (hereinafter referred to as blank space) Table 1 As is clear from Table 1, in each Example, a high density yellow dye image can be obtained, whereas in Comparative Example 1, a low density yellow dye image can be obtained. I can only get images.

Next, in order to examine the storage stability of the images, the image receiving surface of each image receiving material was brought into close contact with a vinyl chloride resin sheet and left at a temperature of 70°C for 24 hours. In contrast, in the image obtained in Comparative Example 2, significant retransfer was observed.

Furthermore, when each of the thermal transfer recording materials was stored in a roll, in the case of Comparative Example 2, noticeable set-off of the dye to the back surface of the thermal transfer recording material was observed.

[Effects of the Invention] According to the heat-sensitive transfer recording material of the present invention, a specific heat-diffusible yellow dye is added to the heat-sensitive layer or heat-fusible layer, so that images with high density and excellent storage stability can be obtained. Furthermore, the thermal transfer recording material itself has excellent storage stability.

Further, according to the thermal transfer recording method of the present invention, the above-mentioned image can be efficiently obtained.

[Brief explanation of the drawing]

FIG. 1 shows the structural formula of a typical yellow dye according to the present invention. FIGS. 2(A) and 2(B) are explanatory diagrams showing the thermal transfer recording method of the present invention. DESCRIPTION OF SYMBOLS 1...Support, 2...Image receiving layer, 3...Image receiving material,
4...Support, 5...Thermosensitive layer. 6...Thermal transfer recording material, 7...Thermal head,
9... Heat-fusible layer, 10... Heat-sensitive transfer recording material. Figure 2 (a) (b)

Claims (2)

[Claims] (1) A heat-sensitive transfer recording material comprising, on a support, a layer containing a yellow dye represented by the following general formula [I]. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ [I] [In the formula, R^1 represents an alkyl group, cycloalkyl group, alkenyl group, or aryl group, and R^2 and R^3 may be the same or different. X represents -O-, -S- or ▲There are numerical formulas, chemical formulas, tables, etc.▼ (However, R^4 represents a hydrogen atom or an alkyl group.), and Y represents Represents an alkyl group, an alkoxy group, a halogen atom or a hydrogen atom. (2) An image-receiving material is superimposed on the layer of a heat-sensitive transfer recording material having a layer containing a dye represented by the general formula [I] according to claim 1 on a support, and the heat-sensitive transfer recording material is converted into image information. 1. A thermal transfer recording method, characterized in that an image is formed on an image-receiving material by heating the dye accordingly and diffusing and transferring the dye to the image-receiving material.