JPS6237190A - Thermal transfer recording medium - Google Patents

Abstract

PURPOSE:To print clear images with little void and high density, by sequentially laminating a specified releasable layer and a thermal transfer ink layer. CONSTITUTION:The thermal transfer recording medium is provided by sequentially laminating the releasable layer having a melting point of 50-100 deg.C and the thermal transfer ink layer on a heat-resistant base. First, a wax, a thermoplastic resin, a softener, or a wax emulsion or a styrene oligomer and a hydrogenated petroleum resin are mixed or dispersed, the resultant material is applied to the heat-resistance base by hot-melt coating or solvent coating, followed by drying to provide the thermal releasable layer. Then, a polyethylene resin, a wax and a coloring agent or the like are dispersed or melt-dispersed in a solvent to prepare an ink coating material, which is applied to the releasable layer by an ordinary hot-melt or solvent coating machine, followed by solidification or drying.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a thermal transfer recording medium used in a thermal transfer recording device such as a thermal facsimile or a thermal printer.

Conventional technology In recent years, non-impact type thermal recording methods have been attracting attention due to noise and ease of handling.However, the conventional thermal recording methods are noiseless and do not require development or fixing. Although it is easy to handle, there are problems with the falsification and preservation of records.

In order to improve these drawbacks, a heat-melt ink layer is provided on the base material, the heat-melt ink layer and receiving paper (recording paper) are overlapped, and the base material is heated with a thermal head from above. However, a heat-sensitive transfer recording method has been proposed in which the heat-melt ink layer is melted and transferred to receiving paper made of plain paper.

Problems to be Solved by the Invention However, even in this thermal transfer recording method, when the smoothness of the receiving paper made of plain paper is high, good printing can be obtained, but when the smoothness is low, for example, the Bekk smoothness is If it takes less than 50 seconds, the unevenness of the surface of the receiving paper will cause some parts of the heat-melting ink layer to come into contact with the receiving paper and some parts not to come into contact with it.
As a result, the transfer efficiency deteriorates and voids occur, resulting in poor clarity.Furthermore, because the fluidity of the hot-melt ink is high, the hot-melt ink penetrates into the receiving paper, resulting in insufficient density.
Good printing could not be obtained.

Means for Solving the Problems The present invention is a heat-sensitive transfer recording medium characterized in that a release layer that melts at 50 to 100° C. and a heat-sensitive transfer ink layer are sequentially laminated on a heat-resistant base material.

That is, it has been found that by the combination of the present invention, high transfer efficiency is achieved due to their interaction, and clear printing with high density and no voids can be obtained.

With combinations other than this one, the transfer efficiency is high and the generation of voids is small, but only prints with poor density can be obtained, and the density is high but the transfer efficiency is poor and only unclear prints with many voids can be obtained.

Preferred configurations of the release layer of the thermal transfer recording medium of the present invention include the following.

A: Wax 90-40wt% thermoplastic resin
O~40wt% Softener 0~30wt Melting point or softening point B: Wax 100~3Qwt% 50~1
00℃ 1 or more types 10-60 wt% 6
0-150℃ thermoplastic resin softener 0-30wt% Liquid at room temperature C: rosin and its derivatives, terpene resin, hydrocarbon resin, α
-Made from one or more selected from methylstyrene-vinyltoluene copolymer, low molecular weight styrene resin, and coumaron-indene resin.

Consisting of D-niwax emulsion.

The heat-resistant substrate that can be used in the present invention is a thin paper of 20μ or less such as glassine paper or a capacitor film, or a heat-resistant film of 10μ or less such as polyester, polyimide, nylon, or polypropylene, but preferably 2 ~10μ plastic film is good.

Materials for the release layer that melt at 50 to 100°C used in the present invention include: paraffin wax, microcrystalline wax, carnauba wax, shellac wax, montan wax, higher fatty acid, higher fatty acid amide, higher fatty acid amide, higher alcohol, etc. Higher fatty acid metal soap wax emulsion Emulsions of the various waxes mentioned above can be used.

Thermoplastic resins include: ・Ethylene-vinyl acetate copolymer ・Polyamide ・Polyethylene ・Polyester Resin that has low viscosity when melted: ・Rosin and its derivatives ・Terpene resin ・Aliphatic, aromatic, aliphatic/aromatic Hydrocarbon resins such as group copolymers and alicyclic compounds, α-methylstyrene-vinyltoluene copolymers, low molecular weight styrene resins, coumaron and indene resins, which may be used alone or in combination. , hydrogenated hydrocarbon resins, and low molecular weight styrene resins can give good results.

Various animal, vegetable or mineral oils can be used as softeners.

As the heat-sensitive transfer ink layer that can be used in the present invention, those conventionally used can be used.

Further, higher fatty acids, fluororesins, silicone resins, etc. are used for the thermal protection layer of the thermal base material Tii'.

The method for manufacturing the heat-sensitive transfer recording medium is as follows.

First, the aforementioned wax, thermoplastic resin, softener, or wax emulsion, or styrene oligomer, or hydrogenated petroleum resin is mixed or dispersed on a heat-resistant base material, coated with hot melt coating or solvent coating, dried, and heat-sensitively released. A mold layer is provided.

Next, the above-mentioned polyethylene resin, wax, colorant, etc. may be dispersed or melt-dispersed in a solvent on the heat-sensitive mold release layer.

If an emulsion or dispersion is still used, the ink is prepared by dispersing the polyethylene emulsion and wax emulsion colorant in water using a dispersion machine such as a ball mill or attritor. At this time, if a commercially available colorant dispersion is used as the colorant, the above components may simply be mixed and stirred.

This ink coating material is applied to a substrate using a conventional hot-melt or solvent-based coating machine, and then solidified or dried. When providing a heat-resistant protective layer on the opposite side of the base material, the above-mentioned materials may be mixed and dispersed in a solvent, applied, and dried.

The thickness of the thermal transfer ink layer is 2 to 10 microns.

Further, in order to further increase the heat resistance of the heat-resistant base material, a heat-resistant medical protective layer is provided, and higher fatty acids, fluororesins, silicone resins, etc. are used there.

Example 4 Fatty acid amide was applied to the upper surface of PET (polyethylene terephthalate) having a thickness of 1μ and a heat-resistant protective layer having a thickness of 1μ was provided.

Next, a coating material as in each example is applied to the other surface to form a 2μ thick heat-sensitive mold release layer, and a coating material as in each example is further applied on the heat-sensitive mold release layer to form a 4μ thick layer. A thermal transfer ink layer was provided.

(T: Good ×: Bad (Test method) Period: 1.2 m sec, applied pulse width: 0.9 m5
ec.

The test is conducted using a thermal printer with a power of 0.5 W/DOT and a BEKK hammer mill bond paper with a smoothness of 1.6 seconds as the receiving paper.

The conventional product Example 1 had many voids and low density, but Examples 2 to 10 had few voids and printed with good density.

According to the present invention, clear printing with few grains and high density can be obtained.

Claims (1)

[Scope of Claims] 1. A heat-sensitive transfer recording medium, characterized in that a release layer that melts at 50 to 100°C and a heat-sensitive transfer ink layer are sequentially laminated on a heat-resistant base material. 2. The release layer that melts at 50 to 100 °C is composed of wax, thermoplastic resin, and softener, and the weight ratio thereof is 40
90 wt%, 0 to 40 wt%, and 0 to 30 wt%, the thermal transfer recording medium according to claim 1. 3. The release layer that melts at 50-100°C is (a) a wax with a melting point of 50-100°C, (b) one or more thermoplastic resins with a softening point or melting point of 60-150°C, and ( c) Thermal transfer according to claim 1, characterized in that it is made of a softener that is liquid at room temperature, and the weight ratios of each are 100 to 30 wt%, 10 to 60 wt%, and 0 to 30 wt%. recoding media. 4. The release layer that melts at 50 to 100°C has a low viscosity when melted, including rosin and its derivatives, terpene resin, hydrocarbon resin, α-methylstyrene-vinyltoluene copolymer, low molecular weight styrene resin, coumaron, etc. The thermal transfer recording medium according to claim 1, characterized in that it is made of one or more selected from indene resins. 5. The thermal transfer recording medium according to claim 1, wherein the release layer that melts at 50 to 100°C is a wax emulsion. 6. The heat-sensitive transfer recording medium according to any one of claims 1 to 5, wherein the heat-resistant base material is a plastic film provided with a heat-resistant protective layer.