JPH0420794B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention is used in printing devices such as printers and typewriters, and the colored ink heated in the area heated by the print control signal is thermally melted and transferred from the base material to the recording paper, and the printing is performed on the recording paper. The present invention relates to a one-time thermal transfer recording medium for forming a desired print image based on control signals. In recent years, the development of thermal recording devices such as thermal facsimile has been remarkable. The recording method in such a thermal recording device is as follows:
In order to enable economical efficiency and high-speed recording, as well as improve the tampering resistance and storage stability of the recording, a recording medium in which a heat-melting heat-sensitive transfer ink layer is formed on a base material is used, and the above-mentioned A preferred method is to print from the back side of the substrate using a heating head to melt the ink layer and transfer a predetermined printed image onto a copy sheet. However, while this thermal recording method has the advantage of being able to record clearly, with high resolution, and with excellent tamper resistance and storage stability, the printed image formed by the thermal transfer ink transferred onto the copy sheet has an extremely smooth and glossy surface, which has the disadvantage that when records have to be read in detail, it can be extremely tiring to the eyes, making it difficult to read for long periods of time. The main object of the present invention is to provide a novel one-time heat-sensitive transfer recording medium that is non-glossy and provides an impression that does not cause eye strain even when reading the record for a long time. In order to achieve the object, the present invention selectively heats the colored ink provided on the base material with a heating head from the back side of the base material. In a one-time thermal transfer recording medium used in a recording method in which a printed image is formed by melting and transferring onto a recording paper, a printed image is added to the heat-melting colored ink when the ink solidifies after being melted and transferred. A powder for roughening the surface, which is at least one powder selected from the group consisting of aluminum silicate, silica, calcium carbonate, zinc white, titanium oxide, aluminum, and aluminum hydroxide, is included in the total amount of colored ink. against 25
It adopts a composition in which ~60% by weight is mixed. The thermal transfer recording medium of the present invention is used as a recording medium in a thermal recording device such as the above-mentioned thermal facsimile, and during recording, the heat-melting colored ink (hereinafter referred to as thermal transfer ink) melts rapidly. It is transferred to form a printed image that is extremely clear and has excellent tamper resistance and storage stability, and since the gloss of the printed image is erased by the powder, it cannot be printed by hand or by type. As with other objects, it does not cause the viewer to feel glare and therefore does not make the viewer's eyes tired, which is a remarkable effect. All of the powders in the present invention are uniformly mixed and dispersed in the thermal transfer ink composition, so that after the ink composition has solidified, it diffusely reflects incident light on the surface of the ink composition, thereby erasing the gloss of the surface. It has a function. Therefore, the powder in the present invention has a particle size of about 0.1 to 20μ, and accounts for 25 to 60% (wt%) of the total amount of the thermal transfer ink containing colorant, binder, and softener as main components. The same applies below). When the particle size of the powder (hereinafter referred to as a matting agent) is larger than the above range, there is a matting effect, but the clarity of the recording becomes poor, and when it is smaller than the above range, there is no matting effect. The effect becomes inferior, which is not desirable. Other components such as the colorant, binder, softener, etc. that are blended into the thermal transfer ink of the present invention are those conventionally used in thermal transfer inks, and are not particularly limited. do not have. That is, as the colorant, various dyes or pigments that have been conventionally widely used in the field of copying paper can be used without any particular restrictions. As the binder agent, materials that can be easily melted by heat are preferably used, such as waxes such as carnauba wax, auricular wax, and microcrystalline wax, and resins such as low molecular weight polyethylene and vinyl polystearate. be done. Examples of softeners include substances that can be easily melted by heat, such as polyvinyl acetate, polystyrene, styrene-butadiene copolymers, cellulose esters, cellulose ethers, and acrylic resins, lubricating oils, and plasticizers. Preferably used. These colorants, binders and softeners are
5 to 50% of the total amount of thermal transfer ink,
The blending ratio is preferably 20 to 90% and 5 to 30%, in which case the resulting thermal transfer ink has very good melt transfer properties. In the present invention, in addition to these components, other components such as thermally conductive substances (for example, black pigments such as acetylene black and lamp black, and metal powder pigments) may be added as appropriate. Of course. The thermal transfer ink of the present invention is obtained by uniformly mixing and dispersing a matting agent in a predetermined ratio into an ink composition consisting of these colorants, binders, and softeners. A thermal transfer ink layer that is formed on a substrate with a thickness of 15 μm or less by hot melt coating, or by dispersing it in an appropriate solvent and solvent coating, and can be suitably adopted in various thermal recording devices. You can get a recording medium. However, the thermal transfer recording medium of the present invention has excellent melt transfer properties during high-speed recording, and can form printed images on copy sheets such as plain paper that are extremely clear, have high resolution, and have excellent tamper resistance and storage stability. In addition, since the surface of the printed image is matte, it has the remarkable effect of not tiring the eyes of the viewer due to glare. Next, the thermal transfer recording medium of the present invention will be explained with reference to Examples. Example 1 6 parts of carbon black (parts by weight,
20 parts of carnauba wax as a binder agent, 20 parts of polyethylene and 5 parts of petroleum resin as a softener were added to the resulting ink composition, and aluminum silicate (average particle size) was added as a matting agent to 100 parts of the resulting ink composition. A heat-sensitive transfer ink was obtained by uniformly stirring and mixing 49 parts (diameter 1.3μ) of 49 parts. This product was coated on glassine paper with a thickness of 15 μm by hot melt coating to obtain a thermal transfer ink layer with a thickness of 5 μm. Attach this to a regular thermal facsimile machine and use the thermal head to record heat on plain paper (high-quality paper with a basis weight of 55 g/ ^m2 ).
A printed image with less gloss, clearness, and excellent tamper resistance and storage stability was obtained. Example 2 20 parts of carbon black, 80 parts of carnauba wax
aluminum silicate (average particle size) as a matting agent to 100 parts of the resulting ink composition.
30 parts of 1.3μ) were added and stirred and mixed uniformly to obtain a thermal transfer ink. This material was heated to 85℃ and coated on 15μ thick glassine paper using hot melt coating.
A thermal transfer ink layer with a thickness of 6μ was obtained. This product was subjected to thermal recording in the same manner as in Example 1, and a clear printed image with little gloss was obtained on plain paper. Comparative Example A thermal transfer ink layer was formed on glassine paper in the same manner as in Example 2, except that anhydrous aluminum silicate as a matting agent was not added. This material was used for thermal recording and a glossy printed image was obtained. For each of the printed images obtained in Examples 1 and 2 and Comparative Example, the degree of matteness of the surface was examined based on glossiness. The test was conducted using a digital angle gloss meter manufactured by Suga Test Instruments Co., Ltd.
Glossiness was measured at an angle of 75° using UGV-4D (JIS Z8741). The results are shown in the table below.

[Table] From the table, the glossiness of each of the printed images obtained in Examples 1 and 2 was significantly reduced by the addition of the matting agent compared to the printed image without the addition of the matting agent (comparative example). It can be seen that it has an extremely excellent matte effect.

Claims (1)

[Claims] 1 By heating the heat-melting colored ink provided on the base material with a heating head from the back side of the base material, the colored ink is selectively melted and transferred onto recording paper to form a printed image. In a one-time thermal transfer recording medium used in a recording method, the heat-melting colored ink contains a powder that roughens the surface of the printed image when the ink solidifies after melt transfer. At least one powder selected from the group consisting of acid aluminum, silica, calcium carbonate, zinc white, titanium oxide, aluminum, and aluminum hydroxide is present in an amount of 25% of the total amount of colored ink.
A thermal transfer recording medium containing ~60% by weight.