JPH0489287A - Thermal transfer recording material and thermal transfer recording - Google Patents

Abstract

PURPOSE:To obtain a recording material with improved color transfer properties and image preservability and visualize a high-density color image efficiently using said recording material by forming a layer which contains a color expressed by a specific formula and/or a color expressed by another specific formula on a support. CONSTITUTION:A recording material with a thermal layer formed on a support consists of a color expressed by formula I and/or a color expressed by formula II, and the color in an azomethine-type color with excellent heat dissipating properties. The thermal layer is formed by applying a paint consisting of two or more than three colors dissolved in a solvent with a binder or dispersed in the form of fine particles, and drying the applied paint. The support is resistant against heat generated by a thermal head and is such as a thin leaf sheet like a capacitor paper or heat-resistant plastic film like polyethylene terephthalate. The color contained in the thermal layer 5 of a thermal transfer recording material 6 consisting of the support 4 and the thermal layer 5 is dispersed and migrated to an image-receiving material 3 due to heat generated by a thermal resistor of a thermal head 8, and is fixed on an image-receiving layer 2 on the support 1.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a heat-sensitive transfer recording material and a heat-sensitive transfer recording method, and more specifically, to improving the transferability of a dye to an image-receiving material and the storage stability of an image. The present invention relates to a heat-sensitive transfer recording material and a heat-sensitive transfer recording method that can efficiently obtain high-density color images using this heat-sensitive transfer recording material.

[Prior Art and Problems to be Solved by the Invention] Conventionally, color recording techniques using ink shellers, electrophotography, thermal transfer, etc. have been considered as methods for obtaining color hard copies.

Among these, the thermal transfer recording system in particular has advantages such as easy operation and maintenance, miniaturization of the device, low cost, and low running cost.

In this thermal transfer recording method, a transfer sheet (thermal transfer recording material) consisting of a meltable ink layer provided on a support is heated by a thermal head to melt and transfer the ink onto a transfer sheet (image receiving material). method, and heat-diffusible dye (
2 of a thermal diffusion transfer method (sublimation transfer method) in which a transfer sheet having an ink layer containing a sublimable dye is heated by a thermal head to transfer the heat diffusible dye to a transfer sheet;
Is there a type of thermal diffusion transfer method? The latter one is the thermal diffusion transfer method, which can control the gradation of the image by changing the amount of dye transferred according to changes in the thermal energy of the thermal head.
It is advantageous for full color recording.

However, in thermal transfer recording using the thermal diffusion transfer method,
The transferability of the dyes used in thermal transfer recording materials is important, and this has a major impact on transfer recording speed, recording temperature, image quality, image storage stability, etc.

Therefore, it is desirable that the dye has the following properties.

(a) Easily thermally diffused (sublimated) under heat-sensitive recording conditions (eg, head temperature, head heating time, etc.).

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

(c) It should be easy to add to thermal transfer recording materials.

(d) The image-receiving material after transfer has good storage stability.

(e) Must have good light resistance, heat resistance, moisture resistance, and chemical resistance.

(to) be easy to synthesize.

However, in the conventional thermal recording field.

It is extremely difficult to find a dye that meets many of these conditions.

For example, relatively recently developed yellow, magenta,
Azomethine type dyes are well known as cyan dyes (for example, Japanese Patent Application Laid-open Nos. 1-1776589 and 1-17).
No. 6590, JP-A No. 63-205288, JP-A No. 64-6
No. 3194, No. 63-91288, No. 63-9128
(Refer to each publication such as No. 9).

It is true that these azomethine type dyes are dyes that meet the above conditions to a high degree, but even so, they are not fully satisfactory in terms of dye transferability and post-transfer storage stability.The present invention aims to improve the above-mentioned situation. It was made for the purpose of

That is, an object of the present invention is to provide a heat-sensitive transfer recording material with improved dye transferability to an image-receiving material and image storage stability, and to efficiently obtain high-density color images using this heat-sensitive transfer recording material. The object of the present invention is to provide a thermal transfer recording method that can be used in a variety of ways.

[Means for solving the above problem] The present invention according to claim 1 for achieving the above object,
The present invention is a thermal transfer recording material characterized by having a layer containing a dye represented by the following general formula [E] and/or a dye represented by the general formula [II] on a support.

The present invention according to claim 2 also provides the following formula [I]
An image-receiving material is overlaid on the layer of a heat-sensitive transfer recording material having a layer containing a dye represented by formula [II] and/or a dye represented by general formula [II] 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 image-receiving material and diffusing and transferring the dye to the image-receiving material.

/ (R2).

/ (R2).

However, in the formula, A represents a coupler residue, R1 represents a hydroxyl group or -N-R', and R3 and R4 are an alkyl group which may have a substituent, or are bonded to each other to form a nitrogen atom. Represents a group of atoms that together form a 5-membered or 6-membered negative ring. ), R2 represents a hydrogen atom or a monovalent group.

m is an integer from 1 to 3.

Furthermore, general formulas [I]E and [II] will be explained in detail.

The above A represents a group capable of forming a dye through an oxidative coupling reaction with a 2- and/or 3-aminopyridine derivative in the presence of an oxidizing agent under liquid or alkaline conditions.

Compounds that provide this group include, for example, groups having an open-chain active methylene such as pivaloylacetanilides and benzoylacetanilides, pyrazolones, pyrazolotriazoles, pyrazolobenzimidazoles, phenols, naphthols, quinolitools, etc. is preferred.

R1 represents a hydroxyl group or -N-R', and R3 and R4 are an alkyl group which may have a substituent (they may be the same or different), or bonded to each other with one nitrogen atom. Represents a group of atoms forming a 5- or 6-membered ring.

Examples of the substituents that an alkyl group may have include a hydroxyl group, a halogen atom (such as a chlorine atom, a fluorine atom, etc.), an alkyl group (such as a methyl group,
ethyl group, isopropyl group, tert-butyl group, etc.), cycloalkyl group (e.g., cyclopentyl group, cyclohexyl group, etc.), aryl group (e.g., phenyl group, etc.), alkenyl group (e.g., 2-propenyl group, etc.), aralkyl group (e.g., For example, benzyl group, 2-phenethyl group), alkoxy group (for example, methoxy group, ethoxy group, isopropoxy group, n-butoxy group, etc.), aryloxy group (for example, phenoxy group, etc.), cyano group, acylamino group (for example, acetylamino groups, propionylamino groups, etc.), alkylthio groups (e.g., methylthio group, ethylthio group, n-butylthio group, arylthio group (e.g., phenylthio group, etc.), sulfonylamino groups (e.g., methanesulfonylamino group, benzenesulfonylamino group, etc.), ureido group (e.g. 3
-methylureido group, 3,3-dimethylureido group,
1,3-dimethylureido group, etc.), carbamoyl group (
For example, methylcarbamoyl group, ethylcarbamoyl group, dimethylcarbamoyl group, etc.), sulfamoyl group (
For example, ethylsulfamoyl group, dimethylsulfamoyl group, etc.), alkoxycarbonyl group (for example, methoxycarbonyl group, ethoxycarbonyl group, etc.), aryloxycarbonyl group (for example, phenoxycarbonyl group, etc.), sulfonyl group (for example, methanesulfonyl group, butanesulfonyl group, phenylsulfonyl group, etc.),
Acyl groups (e.g. acetyl, propanoyl, butyroyl, etc.), amino groups (e.g. methylamino,
ethylamino group, dimethylamino group, etc.).

Among these M substituents, preferred are alkoxy groups,
A methoxy group is particularly preferred.

Preferred alkyl groups as Rz and R4 have 1 carbon number.
~5 alkyl groups, especially alkyl groups having 1 to 3 carbon atoms.

In addition, when R3 and R4 combine with each other to form a 5- or 6-membered ring with one nitrogen atom, the preferable rings include (wherein R5 represents an alkyl group having 1 to 5 carbon atoms,
Preferred is a methyl group. ) can be mentioned.

R2 represents a hydrogen atom or a monovalent group.

As this -valent group, the same substituents as mentioned above for R3 and R4 can be used.

Preferred as R2 is a hydrogen atom or a carbon number of 1 to 5
Among these alkyl groups, methyl group is particularly preferred.

m is an integer from 1 to 3, preferably 1 or 2.

The dyes represented by general formulas [I] and [II], that is, the dyes according to the present invention, are all azomethine type dyes with excellent thermal diffusivity.

1. "Thermal diffusion" as used in the present invention means that when a thermal transfer recording material is heated, the dye is substantially independently diffused and/or in a gas, 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.

Typical specific examples of dyes according to the present invention (D-1 to D-30
) is shown in Figure 1.

Among these, those belonging to yellow pigments are D-1 to
D-10 and 1. Those belonging to magenta pigment are D-
11 to D-20, and those belonging to cyan pigments are D
-21 to D-30.

The dye according to the present invention can be easily produced according to known synthesis methods.

For example, the dye represented by the general formula [I] can be prepared by combining a compound represented by the following general formula [1al] and a compound represented by the following general formula [Ib].
] and can be produced by oxidative coupling in the presence of an oxidizing agent under alkaline conditions.

The dye represented by the general formula [nl can be produced by oxidative coupling of a compound represented by the following general formula [Ial and a compound represented by the general formula [IIbl] in an alkaline environment in the presence of an oxidizing agent. can.

\ (R').

(R2),.

However, in the above general formulas [Ial, [Lbl, [■b]], X and Y represent groups that activate the coupling site, and R', R2, m represent the above general formulas [I], [II]. ]
It is synonymous with .

These oxidative coupling reactions are preferably carried out under alkaline conditions, and the reaction medium may be an organic solvent, an aqueous organic solvent, or an aqueous solution.

In addition, as an oxidizing agent, whether organic or inorganic, the formula [1
b] or [IIb], such as inorganic oxidizing agents such as silver halide, hydrogen peroxide, manganese dioxide, potassium persulfate, and oxygen;
Organic oxidizing agents such as N-bromosuccinimide and chloramine T can be used.

In addition to the above synthesis method, the dye according to the present invention can also be produced by electrode reaction.

When relying on this electrode reaction, current, voltage, supporting electrolyte,
It is necessary to appropriately select solvents, electrodes, etc.

The heat-sensitive transfer recording material of the present invention comprises a layer containing the dye according to the present invention (hereinafter sometimes referred to as a heat-sensitive layer) on a support.

The content of this dye in the heat-sensitive layer is preferably 90.1 g to 20 g per support.

The heat-sensitive layer is prepared by preparing a paint by dissolving two or more of the pigments together with a binder in a solvent or by dispersing them in the form of fine particles in a solvent, and applying the paint onto a support and drying it appropriately. By doing so, it is possible to form.

The thickness of the heat-sensitive layer is preferably 0.1 to 5 gm 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, polydonyl acetal, Nitrocellulose, ethylcellulose, etc. may be mentioned.

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

The amount of binder used is 90.
1 to 50 g is preferred.

The solvents include water, alcohols (eg ethanol, propatool), cellosolves (eg ethyl acetate), aromatics (eg toluene).

xylene, chlorobenzene), ketones (eg, acetone, methyl ethyl ketone), ethers (eg, tetrahydrofuran, dioxane), chlorinated solvents (eg, chloroform, trichloroethylene), and the like.

The support may be one that has good dimensional stability and can withstand the heat of a heat-sensitive head during recording, or a thin paper such as condenser paper or glassine paper, or a heat-resistant material such as polyethylene terephthalate, polyamide, or polycarbonate. A plastic film is preferably used.

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

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. 106997.

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 one or more polymers such as polyvinylpyrrolidone, polyvinyl butyral, and saturated polyester, in order to enhance the retention of one dye.

The heat-sensitive transfer recording material of the present invention can be used to obtain magenta, yellow, and cyan dye images individually from the dyes, but when applied to full-color image recording, a cyan heat-sensitive layer containing a cyan dye, a magenta It is preferable that a total of three layers, a magenta heat-sensitive layer containing a dye and a yellow heat-sensitive layer containing a yellow dye, are sequentially and repeatedly coated on the same surface of the support.

In addition, yellow thermosensitive layer, magenta thermosensitive layer,
a heat-sensitive layer containing a black image-forming substance in addition to the cyan heat-sensitive layer;
A total of four layers may be repeatedly applied in sequence on the same surface of the support.

In the heat-sensitive transfer recording method of the present invention, the heat-sensitive layer of the heat-sensitive transfer recording material and the image-receiving material are overlapped, heat is applied to the heat-sensitive transfer recording material according to image information, and the dye in the heat-sensitive layer is diffused toward the image-receiving material. By transferring, an image is formed on the image-receiving material.

To explain this thermal transfer recording method with reference to the drawings, in FIG. The heat from the heating resistor of the thermal head 8 diffuses and transfers to the image receiving material 3, and it is fixed on the image receiving layer 2 on the support l.

In addition, in the case of FIG. 2 (b) which uses a heat-sensitive transfer recording material in which a heat-melting layer is laminated on a heat-sensitive layer, when the heat-sensitive layer 5 contains the dye, this dye is transferred to the heating resistor of the thermal head 8. The dye is diffused and transferred to the heat-fusible layer 9 by the heat from the dye, and the fusible substance 9a containing the dye causes cohesive failure or interfacial peeling and transfers to the image-receiving material 3 side.

Furthermore, even when a 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 has a support of paper, plastic film, or paper-plastic film combination, and an image-receiving layer formed on the support by polyester resin, polyvinyl chloride resin, vinyl chloride, or other materials. - (for example, vinyl acetate, etc.), one or more polymer layers such as polyvinyl butyral, polyvinylpyrrolidone, polycarbonate, etc. are 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 may be inorganic or organic and is not particularly limited; for example, calcium carbonate, sodium carbonate, sodium acetate, alkylamines, arylamines, etc. may 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.

[Example] Next, the present invention will be explained in more detail with reference to Examples.
The present invention is not limited thereto.

(Example 1) Preparation of a paint - The heat-diffusible dye (D-1) having the above structure was mixed with the following nitrocellulose resin and methyl ethyl ketone to obtain a uniform solution paint.

Heat-diffusible dye (D-1)...10 g Nitrocellulose resin...20 g Methyl ethyl ketone...400 ml - Preparation of heat-sensitive transfer recording material - The above paint , applied onto a polyethylene terephthalate film with a thickness of 4.5 μm using a wire bar so that the coating amount after drying was 1.5 g/d, and dried to form a heat-sensitive layer on the polyethylene terephthalate film. A thermal transfer recording material was produced.

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

1. Preparation of image-receiving material - Polyethylene layers are laminated on both sides of paper, and 0.15 g/m2 of silicone oil is applied as an image-receiving layer on one side of the polyethylene layer [containing a white pigment (Ti0a) and a bluing agent]. Contains vinyl chloride resin with an amount of 5 g/m
” to obtain an image-receiving material.

1. Thermal Transfer Recording Method The thermal transfer recording material and the image-receiving material are stacked so that the surface of the heat-sensitive layer of the thermal transfer recording material and the image-receiving surface of the image-receiving material face each other, and a thermal head is applied from the back side of the thermal transfer recording material,
Image recording was performed under the following recording conditions.

Table 1 shows the results of evaluating the maximum reflection density (D, .) and storage stability of the obtained images in the following manner.

Linear density of main scanning and sub-scanning: 8 dots/■■ Recording power: 0.6 W/dot Heating time of thermal head: Heating time was adjusted stepwise from 20 m5 ec to 0.2 sec.

The maximum reflection density was measured using an optical densitometer [Model PCA-65 manufactured by Konica Corporation.

Evaluation of storage stability.

Nitrocellulose was applied onto a polyethylene terephthalate film having a thickness of 180 gm to a film thickness of 5.0 gm after drying and dried to prepare a sheet for preservability evaluation.

The nitrocellulose surface of this sheet for preservability evaluation was placed on the image-receiving surface of the image-receiving material on which an image was formed, and heat-treated at 140° C. for 30 seconds using a heat module.

Thereafter, the preservability evaluation sheet was peeled off from the image-receiving material, and the state of transfer on the peeled surface was visually evaluated.

○: There is almost no retransfer, that is, the storage stability is good.

△: Slight retransfer is observed.

×: Significant retransfer is observed.

(Examples 2 to 6) Dye D-1 in Example 1 was replaced with D-5, D-11, D-
Example 1 except that 16, D-22, and D-30 were replaced.
Five types of heat-sensitive transfer recording materials were prepared in the same manner as above, and images were recorded under the same recording conditions.

As a result, images with excellent gradation were obtained in all cases.

The characteristics of these images were measured in the same manner as in Example 1, and the results are shown in Table 1.

(Comparative Examples 1 to 4) The dye D-1 in Example 1 was replaced with the following comparative dyes A and B.
, C, and D were used, but four types of thermal transfer recording materials were prepared in the same manner as in Example 1, and images were recorded under the same recording conditions.

The characteristics of these images were measured in the same manner as in Example 1, and the results are shown in Table 1.

Comparative dye A.

Color for comparison.

Comparative dye B; Comparative dye C1 C, H.

As can be seen from Table 1, the thermal transfer recording materials of each example all had high reflection densities.

It has high transferability and excellent storage stability.

(Examples 7 to 10, Comparative Example 5) As shown in FIG. 3, the polyethylene terephthalate film 11 used as a support in Example 1 (having a backing 15 on the back side to prevent static and curling)
Above, a yellow thermosensitive layer 12 containing a yellow dye shown in Table 2, a magenta thermosensitive layer 1 containing a magenta dye shown in the same table.
3. A cyan heat-sensitive layer 14 containing the cyan dye shown in the same table was sequentially coated to prepare a heat-sensitive transfer recording material.

The same binder as in Example 1 was used as the binder for each heat-sensitive layer.

Further, the amounts of dye and binder applied are the same as in Example 1.

Next, using the above thermal transfer recording material and the same image receiving material as in Example 1, a video printer (manufactured by Hitachi, vy-i) was used.
When full-color images were created using oo), in Examples 7 to 10, full-color images with excellent storage stability were obtained as shown in Table 2.

Furthermore, these images had good transferability, fixability, and color reproducibility.

On the other hand, in Comparative Example 5, only a full-color image with poor storage stability was obtained.

Table 1 Table 2 (Example 10) As an intermediate layer on the thermal transfer recording material of Example 9, 5 g of a ball mill dispersion of P-) amide, 7 g of polyvinyl and lolidon, 3 g of gelatin, and 0.3 g of the following hardening agent were added. 100m of aqueous solution containing 0.5g of P-)ruamide
/m'.

Hardener; A thermal transfer recording material was obtained.

Using this heat-sensitive transfer recording material and image-receiving material, a full-color image was recorded using a video printer in the same manner as in Example 9.

Note that plain white paper was used as the image-receiving material.

The resulting image had high transferability and good storage stability, gradation, and single image stability.

Ultraviolet inhibitor: Further, on the intermediate layer, as a heat-melting layer, the following ultraviolet inhibitor (applied amount: 0.1 g/rn'), the following antioxidant (
0.1g/rr+') and ethylene-vinyl acetate copolymer (vinyl acetate content 20% by weight)
[1,2 g/m'] containing carnauba wax (amount 2.0
g/rn') by hot melt coating and C4
H9<t) Antioxidant; [Effects of the Invention] According to the present invention, there is provided a thermal transfer recording material with improved dye transferability to an image-receiving material and image storage stability, and a high It is possible to provide a thermal transfer recording method that can efficiently obtain high-density color images.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing the structural formula of a representative example of the dye according to the present invention. FIGS. 2A and 2B are explanatory diagrams of the thermal transfer recording method of the present invention. FIG. 3 is a sectional view showing an embodiment of the thermal transfer recording material of the present invention. l...Support, 2...Image receiving layer, 3...Image receiving material,
4... Support, 5... Heat-sensitive layer, 6... Heat-sensitive transfer recording material, 8... Thermal head, 9... Heat-fusible layer, 10... Heat-sensitive transfer recording material, DESCRIPTION OF SYMBOLS 11... Polyethylene terephthalate film, 12... Yellow heat-sensitive layer, 13... Magenta heat-sensitive layer, 14... Cyan heat-sensitive layer, 15... Backing layer. Figure 1 lN C2H5C2H5 Figure (Acupoint C2H5C2H40CH3 Figure 1 (Tsutsugo 2) D-18 H3 Figure (Fuj3) D-26: Figure 2 (A) Figure 3

Claims (2)

[Claims] (1) A heat-sensitive transfer recording material comprising, on a support, a layer containing a dye represented by the following general formula [I] and/or a dye represented by the general formula [II]. ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [I] ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [II] [However, in the formula, A represents a coupler residue, R^1 is a hydroxyl group, or ▲ Mathematical formulas, chemical formulas, There are tables, etc. ▼ (where R^3 and R^4 are alkyl groups that may have substituents, or atoms that combine with each other to form a 5- or 6-membered ring with one nitrogen atom) represents a group),
R^2 represents a hydrogen atom or a monovalent group. m is an integer from 1 to 3. ] (2) An image-receiving material is added to the layer of a thermal transfer recording material having a layer containing a dye represented by the general formula [I] and/or a dye represented by the general formula [II] on a support. A thermal transfer recording method comprising the steps of: heating the thermal transfer recording material in accordance with image information to diffuse and transfer the dye to the image-receiving material side, thereby forming an image on the image-receiving material.