JPS6392494A - Thermal transfer recording medium - Google Patents

Abstract

PURPOSE:To obtain a thermal transfer recording medium capable of high-quality printing even on a paper poor in surface smoothness and not generating releasing noise at the time of transfer to a receiving material, by providing an oil layer between a base and a heat-fusible ink layer. CONSTITUTION:This thermal transfer recording medium comprises an oil layer and a heat-fusible ink layer sequentially provided on a usually sheet-shaped base. It is necessary for the oil layer to be easily released from the base when being heated, and the oil layer functions to reduce the tension at the interface between the base and the heat-fusible ink layer. It is preferable that the thickness of the oil layer is 0.015-1mum, and that the thickness of the heat-fusible ink layer is 1-10mum. With the thermal transfer recording medium, favorable printing can be performed by a high-speed printer even on an ordinary poor in surface smoothness, and no releasing noise is generated at time of transfer to a receiving material.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a thermal transfer recording medium that can be used in a high-speed printing printer and provides good print quality even on plain paper with low surface smoothness.

[Prior art]

The transfer type thermal recording method is popular as a plain paper recording method with a simple device, but the print quality is easily affected by the smoothness of the surface of the transfer paper, and it is difficult to print clearly on paper with a poor surface smoothness. It is difficult to print accurately. In order to improve such defects, heat treatment is conventionally performed after printing (Japanese Patent Application Laid-open No. 1983
-76276), magnetic force during transfer (JP-A-52-9654)
9) or electrostatic force (Japanese Unexamined Patent Publication No. 55-65590). Alternatively, a large amount of oily substance may be added to reduce the melt viscosity during transfer (Japanese Patent Application Laid-Open No. 6O-2576
2) Heat-melting ink, for which methods such as thermal sensitization by adding thermally decomposable (JP-A-6O-82389) or thermally-expandable (JP-A-6O-25762) substances have been proposed. A technique that attempts to improve print quality by creating multiple layers has also been proposed in the past, in which heat-melt inks with slightly different melting points are laminated and a pigment is added to one or both of them (
Techniques have been proposed such as JP-A-59-224392) and providing a layer made of a heat-fusible substance containing no coloring material on a heat-fusible ink layer (JP-A-6O-97888).

However, in this method of recording by transferring melted liquid ink, if the surface of the transfer paper is low, the print quality will be lower than that of paper with a smooth surface. Only poor print quality can be obtained,
It has not been possible to fundamentally solve the drawback of transfer-type thermal recording that print quality depends on the smoothness of the surface of the transfer paper.

On the other hand, when thermal energy is applied, the ink, which is mainly composed of a resin that exhibits tackiness but does not melt into a low-viscosity liquid and has a certain degree of mechanical strength, can be applied to transfer paper, which has a poor surface smoothness. By using ink that adheres to the convex portions of the surface and transfers the image so as to cover all four areas, it is possible to print with high quality on transfer paper with poor surface smoothness.

However, such resin inks require more energy to print than conventional wax inks, making high-speed printing impossible, and requiring the use of a support film with excellent heat resistance. This is undesirable because it causes problems with the life of the head and heat accumulation. Further, conventional thermal transfer recording media have the disadvantage that a large peeling sound is generated when transferring to a receptor (transfer paper).

〔the purpose〕

The present invention enables a high-speed printing printer to provide high-quality prints not only on plain paper with good surface smoothness, but also on plain paper (rough paper) with poor surface smoothness, and to be acceptable. An object of the present invention is to provide a thermal transfer recording medium that does not generate peeling sound when transferred to a body.

〔composition〕

According to the present invention, there is provided a thermal transfer recording medium having a heat-fusible ink layer on a support, characterized in that an oil layer is provided between the support and the heat-fusible ink layer. be done.

The present invention will be explained in more detail below.

The thermal transfer recording medium of the present invention is usually formed by sequentially forming an oil layer and a heat-melting ink layer on a sheet-like support.

As the support, conventionally known films and papers can be used as they are, such as relatively heat-resistant plastic films such as polyester, polycarbonate, triacetyl cellulose, nylon, and polyimide;
Cellophane or parchment paper can be suitably used. What is the thickness of the support?

When considering a thermal head as a heat source for thermal transfer, it is desirable that the diameter be about 2 to 15 microns, but there are no particular restrictions when using a heat source such as a laser beam that can selectively heat the thermal transferable ink layer. do not have. In addition, when using a thermal head, the surface of the support that comes into contact with the thermal head may be made of silicone resin, fluororesin, polyimide resin,
The heat resistance of the support can be improved by providing a heat-resistant protective layer made of epoxy resin, phenol resin, melamine resin, nitrocellulose, etc., or it is also possible to use support materials that could not be used conventionally. .

The oil layer needs to be easily peeled off from the support when heated, and serves to reduce the tension at the interface between the support and the hot-melt ink layer.

The oils used in this oil layer include linseed oil,
Vegetable oils such as soybean oil, rapeseed oil, castor oil, and peanut oil, animal oils such as whale oil, lard, and beef tallow, mineral oil, petrolatum, lanolin, regitin, DOP, sodium alkylbenzenesulfonate, sorbitan fatty acid ester, glycerin fatty acid ester, and other polyglycerin fatty acids. Ester, propylene glycol/pentaerythritol fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene sorbitol fatty acid ester, polyoxyethylene glycerin fatty acid ester, polyoxyethylene glycol fatty acid ester, polyoxyethylene alkyl ether, polyoxyethylene phytosterol/phytosterol , polyoxyethylene polyoxypropylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene castor oil/hardened castor oil, polyoxyethylene lanolin/lanolin alcohol/beeswax derivatives, polyoxyethylene alkylamine/fatty acid amide, polyoxy Examples include ethylene alkylphenyl formaldehyde condensates and single chain length polyoxyethylene alkyl ethers, but other known materials can be used as desired.

Moreover, the thickness of the oil layer is 0.05 to 1 μm, particularly 0.05 to 1 μm.
1 to 0.5 μm is suitable. The thickness of the heat-melting ink layer is preferably 1 to 10 μm.

Further, it is desirable to add a coloring agent to the heat-melting ink layer. As the colorant, various dyes and pigments widely used in the fields of printing and recording can be used. The content of the colorant is suitably in the range of 5 to 50% of the heat-melting ink layer. In addition, a dispersant, a penetrant, and an adhesion modifier are added to the heat-melting ink layer as necessary.

Additives such as flow control agents may also be added.

The binder constituting the heat-melting ink layer includes natural waxes such as spermaceti wax, beeswax, lanolin, carnauba wax, candelilla wax, and montan wax;
paraffin wax, microcrystalline wax,
Oxidized wax, ester wax, synthetic wax such as low molecular weight polyethylene, higher fatty acids such as lauric acid, myristic acid, palmitic acid, stearic acid, fromenic acid, behenic acid, higher alcohols such as stearyl alcohol and behenyl alcohol, fatty acid esters of sucrose. , esters such as fatty acid ester of sorbitan, amides such as stearinamide and oleinamide, polyamide resins, polyester resins, epoxy resins,
Polyurethane resin, acrylic resin, vinyl chloride resin, cellulose resin, polyvinyl alcohol resin,
A suitable mixture of petroleum resins, phenolic resins, styrene resins, natural rubber, styrene-butadiene rubber, isoprene rubber, chloroprene rubber, etc., or oils such as mineral oils and vegetable oils may be used.

In order to obtain the thermal transfer recording medium of the present invention, the above-described oil is applied onto a support, and then the above-described heat-melting binder, colorant, and additives are melt-kneaded using a dispersion device such as an attritor. Alternatively, by kneading with a suitable solvent to obtain a heat-melting solution or dispersion ink, these inks are sequentially applied onto the oil layer and dried as necessary to form the oil layer and the heat-melting ink. The layers may be formed in this order.

The planar shape of the thermal transfer recording medium of the present invention is not particularly limited, but it is generally used in the form of a typewriter ribbon or a wide tape used in line printers. It is also possible to use a heat-sensitive transfer recording medium in which heat-melting inks of several different tones are applied in stripes or blocks for color recording.

〔effect〕

Since the thermal transfer recording medium of the present invention has the above-described structure, it can be used in high-speed printing printers not only for plain paper with good surface smoothness but also for plain paper (rough paper) with poor surface smoothness. It is of high practical value because it can provide good printing even when transferred to a receptor and does not generate peeling noise when transferred to a receptor.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to Examples.

Example [Thermofusible ink layer forming component] Paraffin (m, p155'F) 4
Q n-8 = Carnauba wax 15 Carbon black 15 The above mixture was hot-melt dispersed using a heating sand mill disperser to obtain a hot-melt ink layer forming liquid.

Next, a toluene solution of glyceryl monocaprylate was applied onto a 3.5 μm thick polyester film using a wire bar, and dried with hot air at 100° C. for 1 minute to form a 0.3 μm thick oil layer. Next, the heat-melt ink layer forming liquid was applied onto this oil layer by a hot-melt method to form a heat-melt ink layer having a thickness of 4 μm, thereby producing a heat-sensitive transfer recording medium of the present invention.

Comparative Example A comparative thermal transfer recording medium was prepared in the same manner as in the example except that the oil layer was omitted.

Using the thermal transfer recording media of Examples and Comparative Examples obtained as described above, copy paper Xerox 4024 paper (manufactured by Xerox Corporation; smoothness 20 seconds by Beck smoothness meter) was transferred to a commercially available thermal printer (JP70D: Renow). When thermal transfer recording was carried out using a printing press (manufactured by Co., Ltd.), the examples produced almost no peeling sound and gave clear prints on the recording paper without blurring or blurring. On the other hand, in the comparative example, a loud peeling sound was generated, and the print was noticeably blurred and blurred, making it impossible to obtain a clear image.

Claims (1)

[Claims] (1) A heat-sensitive transfer recording medium having a heat-fusible ink layer on a support, characterized in that an oil layer is provided between the support and the heat-fusible ink layer.