JP2590833B2 - Thermal transfer recording medium - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a thermal transfer recording material used for thermal transfer recording in which characters and images are recorded by a transfer method using a thermal head, a thermal pen, or the like. .

(Prior art) In recent years, a thermal transfer recording method using a thermal head has
The recording apparatus is widely used because of its advantages such as relatively low cost, low noise during printing, and easy maintenance of the recording apparatus.

Taking advantage of this characteristic, in the label industry, a bar code, a product name, a price, and the like are printed on a label by using this method, and a label of a small lot type is created. The bar code on the label is read using, for example, a light pen. At this time, the shape of the bar code made of the transfer ink is often broken due to abrasion at the tip of the light pen, so that accurate information cannot be read. The same thing is likely to occur when a product to which a barcode-printed label is attached touches a surrounding item during handling. Currently, the wax-based thermal transfer ink, which constitutes the transfer layer of the thermal transfer recording material used for thermal transfer recording, is soft in itself and has abrasion resistance, and is printed on resin-coated paper such as mirror-coated paper. In this case, the abrasion resistance is particularly reduced.

(Object of the Invention) The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a heat-sensitive transfer recording material in which printed characters have extremely excellent wear resistance.

DETAILED DESCRIPTION OF THE INVENTION Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 shows a schematic configuration of one embodiment of a thermal transfer recording material (1) according to the present invention, wherein (2) is a substrate, (3) is a release layer,
(4) indicates a colored layer, and (5) indicates an adhesive layer.

The thermal transfer recording medium of the present invention is not limited to such a configuration, and may have a configuration in which a protective layer (6) is provided for preventing sticking as shown in FIG.

In such a configuration, the substrate (2) may be a film or sheet generally used as a support of a thermal transfer recording medium, and specifically, a stretched polyester film, a capacitor paper, or the like. can give.

The release layer (3) provided thereon is between the base material (2) and a colored layer (4) described later, and is used to make the degree of release at the time of transfer constant and to obtain clear printing. Its constituents are carnauba wax with a melting point of 50-200 ° C,
A composition mainly composed of rice wax, candelilla wax, montan wax, and paraffin wax is exemplified.

On the other hand, the coloring layer (4) is composed of a composition containing a thermoplastic resin and a coloring agent (pigment; dye) as main components and not containing wax. As the thermoplastic resin, ethylene vinyl acetate resin, acrylic resin, polyamide resin, nitrocellulose resin, styrene acrylic resin, chlorinated rubber, rosin ester, hydrogenated rosin ester, ester gum, perhydrogenated rosin ester, resole type alkylphenol, ketone resin And styrene resin.

The adhesive layer (5) is mainly composed of a polyamide resin having a softening point of 90 to 180 ° C., which serves to improve the adhesion to the image receiving paper. Further, since this layer does not contain a coloring material, it also has a role of preventing background contamination at the time of printing. This polyamide resin is
It is necessary to change physical properties depending on the thicknesses of the release layer and the colored layer. When the thickness of the release layer and the coloring layer is large, a low softening point within the range of the softening point described above, and a material having a low melt viscosity,
On the other hand, when it is thin, a material having a high softening point and a high melt viscosity is preferred. If the softening point of the resin is 90 ° C. or lower, the storage stability of the recording medium itself deteriorates, and if it is 180 ° C. or higher, a situation in which the resin is not transferred at the time of transfer occurs.

The protective layer (6) shown in FIG. 2 is provided to prevent sticking. The protective layer (6) is made of a resin having good heat resistance, such as polyolefin resin, nitrocellulose resin, silicone resin, fluorine resin, polyimide resin, or silicone oil. It contains a lubricant.

(Effects of the Invention) Since the present invention has the above-described structure, the adhesive strength of the adhesive layer as the top layer is improved, and the adhesive layer strongly adheres to the image receiving paper at the time of printing. Therefore, it is harder than a conventional wax-based material, and the abrasion resistance is greatly improved overall.

(Examples) Hereinafter, preferred examples of the present invention will be described.

First, a 5.7 μm-thick polyester stretched film was prepared as shown in Table 1.
A varnish having the composition shown in Table 1 was uniformly applied at a rate of 1.5 g / m ² on a dry basis to form a release layer. Next, an ink having the composition shown in Table 2 was uniformly applied on the release layer at a dry weight ratio of 0.8 g / m ² to form a colored layer. Finally, a varnish having the composition shown in Table 3 was applied on the colored layer at a dry weight of 0.5 g / m ² to prepare a thermal transfer ribbon.

Using this thermal transfer ribbon, evaluation was made under the following conditions.

First, the thermal transfer ribbon created by the method described above, and 5.7μ
A one-layer comparative thermal transfer ribbon coated with a hot-melt type ink composed mainly of wax and pigment at a rate of 2.5 g / m ² onto a polyester stretched film is loaded into a thermal transfer printer for bar code printing in sequence. Then, printing was performed on labels of resin-coated paper and high-quality paper, and the printed matter was evaluated.

The evaluation items are printability (clearness of printed matter), background stain, and abrasion resistance.

The printability and the background stain are visually evaluated, and the abrasion resistance is visually evaluated by rubbing with a cotton cloth 50 times using a gakshin abrasion tester, transferring the ink to the cotton cloth, and rubbing the printed matter by rubbing. Table 4 shows the results.

[Brief description of the drawings]

FIG. 1 is a schematic structural explanatory diagram of one embodiment of the present invention, and FIG. 2 is a schematic structural explanatory diagram of another embodiment of the present invention. (1) Thermal transfer recording material (2) Substrate (3) Peeling layer (4) Ink layer (5) Adhesive layer (6) Protective layer

Claims (1)

(57) [Claims] 1. A heat-sensitive transfer recording material comprising at least one heat-sensitive transfer layer mainly composed of a heat-fusible composition on one surface of a substrate, wherein the heat-sensitive transfer layer comprises a release layer, a colored layer, an adhesive The release layer is composed of a composition mainly composed of a wax having a melting point of 50 to 200 ° C., and the coloring layer is composed of a composition mainly composed of a colorant and a thermoplastic resin and containing no wax. And a thermal transfer recording material, wherein the adhesive layer is made of a composition mainly composed of a polyamide resin having a softening point of 90 to 180 ° C.