JPH02147292A - Thermal transfer recording medium - Google Patents

Abstract

PURPOSE:To enhance transfer properties and to prevent abrasion smearing by providing an undercoat layer based on a resin having a specific glass transition point and/or wax having specific penetration to the upper surface of a heat-resistant base material and providing a heat-meltable ink layer to the upper surface thereof. CONSTITUTION:An undercoat layer having function having enhanced transfer properties and covering a transferred heat-meltable ink layer to protect the same is provided between the base material and heat-meltable ink layer of a thermal transfer recording medium. The undercoat layer is based on a resin and/or wax and, as the resin component, one or more kind of a resin having a glass transition point of 70 deg.C or less such as an ethylene-vinyl acetate copoly mer, an acrylic resin or an ethylene-acrylic copolymer is used. As the wax, one or more kind of one having penetration of 5 or less (at 25 deg.C) such as carnauba max. montan wax or candelilla wax is used. With respect to the pref. compounding of the resin and the wax, the resin is 0-50wt.% and the wax is 50-100wt.%.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to a thermal transfer recording medium, and more particularly to a thermal transfer recording medium that is effective in preventing scratches on a transferred ink layer.

Thermal melting of thermal transfer recording media in which a heat-melting ink layer is provided on a film made of polyester resin or polyimide resin, or a thin paper such as glassine paper, tracing paper or condenser paper. There is a known thermal transfer recording method in which plain paper or a tag is superimposed on the surface of the thermofusible ink layer and heated from the substrate side with a thermal head to melt the heat-fusible ink layer and transfer it to the plain paper or tag. .

However, plain paper and tags onto which the heat-fusible ink layer was transferred using this method had the disadvantage that they were easily stained by rubbing the heat-fusible ink layer. Therefore, an object of the present invention is to provide a heat-sensitive transfer recording medium that can prevent a heat-melting ink layer transferred onto plain paper or a tag from being scratched and stained.

4! ! This invention provides a method for improving transferability between the base material and the heat-melt ink layer in a heat-sensitive transfer recording medium in which a heat-melt ink layer is provided on the base material. Moreover, it is characterized by providing an undercoat layer having a function of covering and protecting the transferred heat-melting ink layer.

As the base material, a film made of the aforementioned polyester resin or polyimide resin, or thin paper such as glassine paper, tracing paper, or condenser paper can be used.

The undercoat layer is mainly composed of resin and/or wax, and may also contain fillers and the like.

As the resin component, one type of resin with a glass transition point of 70°C or lower such as ethylene-vinyl acetate copolymer, acrylic resin, ethylene-acrylic copolymer, polyvinyl acetate, ethyl cellulose, polyvinyl butyral, rosin, polyester, etc. Alternatively, good results can be obtained by using two or more types.

Good results can be obtained by using one or more waxes such as carnauba, montan, candelilla, paraffin, rice wax, polyethylene wax, etc., which have a penetration degree of 5 or less (at 25° C.).

As fillers, fine powders such as calcium carbonate, barium sulfate, aluminum oxide, and silica can be used.A suitable blend of resin and wax is 0 to 50% by weight of resin.
, the wax content is preferably 50 to 100% by weight.

If it is outside this range, the ink may peel off from the base material or the printed characters may be transferred onto the film, which is not preferable.

Next, the heat-melting ink layer is made of colorants containing commonly known pigments and dyes such as carbon black and graphite, waxes such as carnauba and microcrystalline wax, and polyamide, acrylic resin, and ethyl acetic acid. In addition to resins such as vinyl copolymers and ethyl cellulose, fillers made of fine powders such as calcium carbonate, barium sulfate, aluminum oxide, and silica, and additives such as lubricating oil can be added.

The thermal transfer recording medium of the present invention has a protective layer that prevents sticking caused by melting of the base material due to the heat of the thermal head by coating one side of the base material with silicone resin or surfactant fl, if necessary. A coating material mainly composed of resin and/or wax is applied to the other surface of the cough substrate by a commonly used coating method such as a solvent coating method or an emulsion coating method to form an undercoat layer (a suitable method is used). The thickness is 1 to 4μ), then
It can be easily manufactured by forming a heat-melting ink layer on this undercoat layer by a conventional method (the preferred thickness is 1 to 5 μm).

50 parts of carnauba wax emulsion 50 parts of ethylene-vinyl acetate copolymer emulsion (30% solution) Apply the above coating to a thickness of 3μ on the other side of a 5μ thick polyester film with a heat-resistant treated layer on one side to prevent sticking. I applied it so that it was smooth.

Carbon black 10 parts Carnauba wax 10 parts Polyamide resin
10 parts isopropyl alcohol
70 parts The above formulation is ground and mixed in a ball mill to prepare a coating material. Apply 2μ of this material on top of the undercoat layer.
It was applied to a thickness of .

Print a barcode using this thermal transfer recording medium and
When a test was carried out using a friction tester (type ■) according to the IS standard (LO823), no change was observed in the print even after 50 reciprocating tests.

Also, after soaking it in engine oil, I tested it in the same way as above, and no scratches were visible. A similar test was conducted with gasoline and found similar effects.

Next, sandwich the printed material between pieces of cloth and iron it” (150 yen).
When a heat resistance test was carried out by applying a temperature of 30°F (°C), no change was observed in the printing.

70 parts of carnauba wax emulsion (30% solution) 30 parts of acrylic emulsion (30 solution) 25 parts of carbon black (30% solution) dispersed in water (30% solution) 30 parts of acrylic emulsion (30% solution) 30% solution) 45 parts A thermal transfer recording medium was prepared in the same manner as in Example 1, and the same tests were conducted, and similar results were obtained.

Carbon black 20 parts Carnauba wax 30 parts Paraffin wax
40 parts Ethylene-vinyl acetate copolymer resin 10 parts The above composition is crushed and mixed in a ball mill to create a coating material, and the coating material is coated with a heat-resistant treated layer on one side to prevent sticking. The above coating material was applied to the other side of the 5μ polyester film to a thickness of 2μ.

When the same test as in Example 1 was conducted, the print became smeared after 5 reciprocations and could no longer be read by a barcode reader. Also, engine oil and gasoline immersion tests soon became dirty and the barcode reader could no longer read them.

Next, sandwich the print between cloth and iron (150℃)
) and conducted a heat resistance test, the hot-melt ink melted and transferred to the cloth.

When a heat-melting ink layer is transferred to plain paper, tags, labels, stickers, etc. using the heat-sensitive transfer recording medium of the present invention,
The undercoat layer covers the hot-melt ink layer, making it extremely resistant to scratches and stains.

At the same time, it has excellent heat resistance and solvent resistance, and in addition, the undercoat layer has a release effect and improves transferability.It can be used not only for plain paper and paper tags, labels, and stickers, but also for textile tags, labels, and stickers. It is now possible to use up to.

hand Continued Yes 1j Positive book Heisei 1 year February 20th

Claims (1)

[Claims] 1. An undercoat layer mainly composed of resin and/or wax is provided on the top surface of a heat-resistant base material, and a heat-melting ink layer is provided on the top surface of the undercoat layer. Features of thermal transfer recording media. 2. The glass transition point of the resin of the undercoat layer is 70
2. The thermal transfer recording medium according to claim 1, wherein the temperature is below .degree. 3. The thermal transfer recording medium according to claim 1, wherein the wax in the undercoat layer has a penetration degree of 5 or less at 25°C. 4. The thermal transfer recording medium according to claim 1, wherein the undercoat layer comprises 0 to 50% by weight of resin and 50 to 100% by weight of wax. 5. The heat-melting ink layer mainly contains a colorant, a filler,
The thermal transfer recording medium according to claim 1, comprising wax and resin. 6. The wax of the heat-melting ink layer has a penetration degree of 10 or less at 25°C, and the resin has a glass transition point of 70.
6. The thermal transfer recording medium according to claim 5, wherein the temperature is below .degree. 7. The heat-melting ink layer contains 10 to 30% by weight of a colorant;
The thermal transfer recording medium according to claim 6, comprising 10 to 50% by weight of resin and 20 to 60% by weight of wax.