JPS6056592A - Thermal sensitive recordng transfer unit - Google Patents

Abstract

PURPOSE:To enable to use a base of low heat resistant film by forming a heat protecting layer between the base of a heat sensitive recording transfer unit and a colorant layer, thereby eliminating the decrease in the recording density even for high heat energy recording. CONSTITUTION:A heat resistant protecting layer is formed on a base of polyethylene terephthalate. Curable resin of 80 deg.C or heat deforming temperature and particularly photocurable material of oligoacrylate or aromatic diazonium salt catalyst (e.g., aryldiazonium hexafluorophosphate) to preferably form a photocurable material of eopxy resin, and the other melting point of approx. 300 deg.C or higher in a metal (oxide) can be used. Then, a colorant layer is formed on the protecting layer as an object heat sensitive recording transfer unit. When a sublimed dye which starts subliming at temperatures of approx. 30 deg.C or lower is used, excellent function for reproducing a halftone picture.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a transfer body for thermal recording used in recording by thermal transfer, and particularly relates to an improvement of the substrate.

Conventional Structures and Problems Typical types of transfer bodies for thermal recording are the wax method, in which the coloring material layer is made of a heat-melting material, and the sublimation dye method, in which the coloring material layer contains a sublimable dye. There is a transcript. The color tocovies obtained from both transfer bodies each have their own special characteristics, but the latter is particularly distinctive in that it is easy to reproduce halftones of color and is beautiful. However, compared to the former method, a large amount of thermal energy is required to sublimate or evaporate the dye. Conventionally, capacitor paper or polyester film has been mainly used as the substrate. Condenser paper has excellent heat resistance, but has uneven heat conduction due to uneven density. On the other hand, although polyester film has no density unevenness, it has poor heat resistance, so K used for high density printing by high temperature heating is insufficient.

In other words, when a polyester film is used as the substrate for a sublimation dye method, when heat energy is applied to the head to obtain the required recording density, the heat absorption by the polyester film itself or the diffusion phenomenon of the dye into the substrate is sufficient. We discovered that the drawback is that it is not possible to obtain a high print density.

OBJECTS OF THE INVENTION It is an object of the present invention to provide a transfer member for thermal recording which eliminates the above-mentioned conventional drawbacks and which does not cause a decrease in print density even when a substrate with poor heat resistance is used.

Structure of the Invention The present invention is a transfer body using a substrate having a heat-resistant protective layer between the substrate and a coloring material layer.

Description of examples Examples of the present invention will be described below.

Among thermal recording transfer bodies (hereinafter referred to as transfer bodies) used for thermal transfer recording, sublimation dye transfer bodies in which the color material layer contains a sublimable dye require a large amount of heat to sublimate or evaporate the dye. Requires energy. Therefore, if a film with a low melting point and melted or softened by the heat of the head is used as a substrate, the thermal energy applied to sublimate or evaporate the dye is absorbed by the substrate, or 1, the dye is transferred into the softened substrate. Diffusion occurs, resulting in a decrease in recording density. However, if a heat-resistant protective layer is provided between the substrate and the coloring material layer, the above phenomenon can be prevented and an excellent transfer body can be obtained.

For the heat-resistant protective layer, any heat-resistant material can be used as long as it does not cause any adverse effects during heat-sensitive recording. In particular, a curable resin that has good adhesion to the substrate during recording and has a heat deformation temperature or load deflection temperature of 80° C. or higher exhibits good characteristics. Here, the heat distortion temperature or the deflection temperature under load is determined by the American Society for Testing and Materials test method (ASTM, D648, load 1B,
6Jc? /cnI).

Heat is used for hardening resins.

There are various resins that can be cured by light or electron beams. Among these, photocurable resins are easily cured in a short time and are easy to produce long transfer bodies.

All photo-curable resins exhibit good properties, but among them, photo-cured products of oligoacrylates or photo-cured products of epoxy resins using aromatic diazonium salt catalysts are excellent because of their fast curing speed.

Examples of aromatic diazonium salt catalysts include allyl diazonium hexafluorophosphate.

Examples include allyldiazonium fluoroborate and allyldiazonium hexafluoroantimonate.

In addition to the above-mentioned curable resins, metals, metal oxides, and inorganic compounds having a melting point of 30° C. or higher are useful as the heat-resistant protective layer.

The substrate is not particularly limited, and a polymer film, sheet, etc. having a melting point of 300° C. or less can be used. For example, polyethylene terephthalate.

Polyester polymers such as polyethylene naphthalate and polycarbonate, polyolefin polymers such as polypropylene and poly-4-methylpentene, cellulose acetate polymers such as acetyl cellulose, polyvinylidene fluoride, 4-fluoride, ethylene-fluoride, etc. Examples include fluorinated polymers such as propylene chloride copolymers. Polyethylene terephthalate is particularly useful because it is thin and can be used as a general-purpose product.

When a sublimable dye that starts to sublimate or evaporate at a temperature of 300° C. or lower is used as the coloring material, it exhibits an excellent function in reproducing halftone image quality. Sublimable dyes and (-), for example, basic dyes, 1 disperse dyes, etc. can be used.

This will be explained in more detail below.

Example 1 A polyethylene terephthalate (hereinafter abbreviated as PET) film with a thickness of 12 μm is used as a substrate.

On this upper surface, an ink containing 2 parts by weight of a dye represented by the molecular structure A below, 4 parts by weight of polycarbonate, and 100 parts by weight of methylene chloride was applied with a wire bar, and the mixture was heated to 60°C.
A transfer body was prepared by drying with hot air. This transfer body is called a.

Next, a polyester acrylate resin (having the molecular structure B below) (
Viscosity, 8o○○ centipoise), J31- Trimethylolpropane acrylate curing agent as reactive monomer and benzoin 0 0 0 CI (2-(EH-C-0←○-C-(CH2)4.,
-c-0-(CH2)6 Ino 1) Kdo C-CH residence, ・ ・ Mon) Ethyl ether, P-dimethylaminobenzaldehyde, and methylene chloride and ethyl acetate as solvents, respectively:
After applying the resin liquid mixed at a weight ratio of 1:1:1:50:50 with a roller, it was dried with hot air at 60°C.
It was cured by irradiation with a KW high-pressure mercury lamp. The thickness of the cured film was 0.4 μm11.

The same ink as that of transfer body a was applied to the surface of this cured film to prepare a transfer body. This transfer body is called b.

Using the above transfer body, the back side was coated with Vcl DI J and recorded on activated clay coated paper under the following thermal head recording conditions.

Main and sub-scanning linear density: 4 dots/lnm recording power
:0.7W/dot head heating time, 2~B? 715 Raft As a result, the relationship between recording density and pulse 1 when transfer bodies a and b were used was the curve shown in FIG. When transfer body a is used, the recording density is almost constant at a pulse of 116 years or more, but the recording density of the transfer body provided with a heat-resistant protective layer is 2777SC'C to 8711SeC1 during the pulse.
increases almost constantly.

Example 2 A 12 μm polyimide film is used as the base.

On this upper surface, 2 parts by weight of a dye represented by the following molecular structure C, 4 parts by weight of polysulfone represented by the following molecular structure,
An ink mixed with 100 parts by weight of monochlorobenzene was applied using a wire bar, and then dried with hot air at 60° C. to produce a transfer body.

This transfer body is called C.

＼C2H5・・・・・・(0 Next, the thickness is 9 μ2) Epoxy acrylate resin (viscosity 15
0 voids), benzine ethyl ether and P-dimedelaminohens altehyde as a curing agent and curing accelerator, and acetone as a solvent at a ratio of 45:2.25:4:10, respectively.
After applying the resin liquid mixed at a weight ratio of 0 with a roller,
60℃ hot air 0 0 0 CH2-CH-C-0(-0-C-(CH2)4-C-
0-(CH2) 690-oc-1 Purchase 2-8-=(5) It was dried and cured by irradiation with a 2 KW high pressure mercury lamp. The thickness of the cured film was 3 μm. The same ink as that for transfer body C was applied to the surface of this cured film to produce a transfer body. This transfer body is called d.

Using the above transfer paper, recording was carried out on activated clay coated paper under the same recording conditions as in Example 1.

As a result, the relationship between recording density and pulse duration when the transfer body CD was used was a curve shown in FIG. 2.

If PET film with low heat resistance is also provided with a heat-resistant protective layer,
A recording density comparable to that of polyimide film, which has excellent heat resistance, can be obtained.

Effects of the Invention As described above, the heat-sensitive recording transfer material of the present invention, which has a heat-resistant protective layer between the coloring material layer and the substrate, does not cause a decrease in recording density even when recording with high thermal energy. Low heat resistant films such as polyester films, which cannot be used for energy recording, can also be used, and the versatility and thin film properties of these films can be utilized.

[Brief explanation of drawings]

FIGS. 1 and 2 are characteristic diagrams showing the relationship between recording density and pulse width of a transfer body for thermal recording in an embodiment of the present invention, respectively. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Fig. 2 o 2 4 6 B pulse '17 z (c.

Claims (1)

[Scope of Claims] (1) A transfer body for heat-sensitive recording comprising a heat-resistant protective layer provided on the upper surface of a substrate and a coloring material layer provided on the upper surface of the heat-resistant protective layer. (2) The transfer body for thermal recording according to claim 1, wherein the substrate is a polyester polymer. (3) The transfer body for heat-sensitive recording according to claim 1, wherein the heat-resistant protective layer is a curable resin having a heat deformation temperature of 80° C. or higher. (4) The transfer body for heat-sensitive recording according to claim 1, wherein the heat-resistant protective layer is a photocurable resin or a thermosetting resin. (6) The heat-sensitive recording transfer material according to claim 1, wherein the heat-resistant layer is a photocured product of oligoacrylate or a photocured product of epoxy resin catalyzed by an aromatic diazonium salt. (6) The transfer body for heat-sensitive recording according to claim 1, wherein the heat-resistant layer is a metal or a metal compound. (7) The transfer body for thermal recording according to claim 1, wherein the coloring material of the coloring material layer is a sublimable dye.