JPH011585A - Thermal transfer material - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a thermal transfer material used for thermal transfer recording, and particularly to a thermal transfer material that provides matte printing.

(Prior art) The printing mechanism using the thermal transfer method has a heat-melting ink layer on one side of a base film as a base material.

In a state where the ink layer and the transfer sheet are overlapped.

A heat-melting ink layer is melted and transferred from the other side of the base film using a heating means such as a thermal head, and a print or image is obtained on the transfer sheet according to the information given to the heating means. .

Traditionally, as base materials, paper such as condenser paper and glassine paper, and heat-resistant films with smooth surfaces such as polyester, polyimide, polycarbonate, polyamide, and polypropylene have been used. One with a layer of meltable ink.

The transfer surface transferred by the above-mentioned method has high smoothness and becomes a glossy transfer print surface because it peels off at the interface between the smooth base film and the hot-melt ink.

Such a glossy surface has a high sense of density, so it is prized for full-color printing. However, for printed materials that require legibility, such as single-character information, glossy surfaces are generally not preferred because they cause eye fatigue, and matte printed materials are desired.

As a means of giving matte printed matter, Japanese Patent Application Laid-Open No. 60-101
Publication No. 083 discloses a method of providing a mantle layer having an uneven surface in which an inorganic filler or the like is dispersed in a resin on a base film;
Furthermore, Japanese Patent Application Laid-open No. 101084/1984 proposes a method of providing unevenness on the base material itself by a method such as sandblasting.

In these methods, peeling occurs at the interface between the hot-melt ink layer and the matte layer during transfer and peeling, and as a result, the unevenness of the matte layer is molded onto the surface of the transferred print, resulting in a matte effect. However, not only is the effect not sufficient, but when the matte layer is provided on the base material, the thickness of the base material becomes the same as that of the matte layer.

Causes a decrease in sensitivity. Furthermore, when providing unevenness on the surface of the base material, there are drawbacks such as difficulty in controlling the unevenness, leading to increased costs.

(Problems to be Solved by the Invention) The present invention provides a heat-sensitive transfer material that eliminates the various drawbacks caused by forming an uneven surface on a base material as described above and has an excellent erasing effect.

[Structure of the invention]

(Unfortunate Means for Solving the Problems) That is, 1. In a heat-sensitive transfer material in which a heat-melt ink layer is provided on a base material, agglomeration occurs between the base material and the heat-melt ink layer during thermal transfer. The heat-sensitive transfer material is provided with a layer that causes destruction and is characterized by a transfer print having a matte effect.

According to the present invention, the matting effect is due to the cohesive failure of the cohesive failure layer containing a specific compound during transfer and peeling of the ink layer, and the unevenness of the destroyed surface.

Examples of the compound contained in the cohesive failure layer of the present invention include higher fatty acid metal salts or derivatives thereof represented by the following formula: % m = 1 to 3 + Me represents a metal. Typical derivatives of higher aliphatic metal salts include hydroxyl derivatives 1, for example, 12-hydroxystearic acid represented by the formula %) Me (m = 1 to 3, where Me represents a metal). metal salts, etc.

Metals that form higher fatty acids or their derivative salts include lithium, sodium, potassium, magnesium,
Examples include calcium, barium, zinc, aluminum, and the like.

Also, the general formula % formula % or -ritual C, Hz--+ CON H (CHz) lIN H
A higher fatty acid amide represented by COCn Hz=+ (n=11-31.m=1-12) or a derivative thereof can be used similarly. Examples of derivatives of higher fatty acid amides include I2-hydroxystearic acid amide represented by the formula %.

The compounds used in the cohesive failure layer in the present invention are not limited to these compounds. When the above-mentioned compound is used, it is suitable that its melting point is 100 to 300°C, preferably 130 to 250°C.

The following compounds can be exemplified.

Lithium stearate (melting point 220”c) Sodium stearate (melting point 220°C) Calcium stearate (melting point 179°C) Magnesium stearate (melting point 1
32°C) Zinc stearate (melting point 140°C) Sodium oleate (melting point 235°C) Potassium oleate (melting point 235-240°C) Lithium myristate (melting point 223°C) Aluminum palmitate (melting point 22°C)
0°C) Sodium palmitate (melting point 270°C) Lithium palmitate (melting point 224°C) Calcium 12-hydroxystearate (melting point 148°C; industrial purity) Lithium 12-hydroxystearate (melting point 216°C)
: Industrial purity) Stearic acid bisamide (melting point 136°C: industrial purity) Ethylene bisstearylamide (melting point 140°C: industrial purity) NN'-Hexamethylenebis-hydroxystearic acid bisamide (melting point 134°C: industrial purity) ) The cohesive failure layer according to the present invention may be a layer consisting only of the above-mentioned compound alone, or a layer containing wax or a thermoplastic resin may be formed on the base material.

The wax incorporated in the cohesive failure layer is effective in controlling the matting effect. In other words, if the cohesive failure layer contains a large amount of higher fatty acid metal salts, higher fatty acid amides, or their derivatives, the transferred cohesive failure layer may turn white and hide the printed matter in some cases. Wax is added to increase the transparency of the cohesive failure layer and provide a suitable matting effect. Also, wax.

It is effective in improving the adhesion between the hot-melt ink layer and the cohesive failure layer and efficiently causing cohesive failure. It is preferable that the amount of wax is 96% or less of heavy oil in the total components forming the cohesive failure layer, and if it is blended in excess of this value,
During thermal transfer, the cohesive failure layer tends to separate from the base material without causing cohesive failure.

The wax blended into the cohesive failure layer in the present invention has a melting point of 50 to 100°C, preferably 50 to 90°C. These waxes include 2 natural waxes such as candelilla wax, carnauba wax, and rice wax.

Wood wax, vegetable waxes such as jojoba oil, and beeswax.

Animal-based waxes such as lanolin and spermaceti; mineral-based waxes such as montan wax, osichelite, and secylene; petroleum-based waxes such as paraffin wax, microcrystalline wax, and petrolatum; and synthetic waxes such as Fischer-Tropish wax and polyethylene wax. Synthetic hydrocarbons, Monkun wax derivatives 5, paraffin wax derivatives.

Examples include modified waxes such as microcrystalline wax derivatives, hydrogenated waxes such as hydrogenated castor oil and hydrogenated castor oil derivatives, and fatty acids such as lanolic acid, valmitic acid, myristic acid, stearic acid, and 12-hydroxystearic acid.

Thermoplastic resins are effective in controlling the viscosity of coating liquids by dissolving them in solvents in solvent coating, and also have the effect of controlling the tone of the matte effect. The blending amount of thermoplastic resin is based on all components of the cohesive failure layer.

Preferably 1 to 30% by weight, more preferably 1 to 30%.

If the amount exceeds 30 parts by weight, the adhesiveness of the cohesive failure layer will become strong, resulting in the thermal transfer material not peeling off from the transfer sheet after printing, or the cohesive failure property of the base material. The cohesive failure layer does not cause destruction during thermal transfer, such as peeling between the layers or between the heat-melting ink layer and the cohesive failure layer.

The thermoplastic resin blended into the cohesive failure layer in the present invention is as follows.

Those having a softening point of 200°C or lower, preferably 180°C or lower1, such as polyvinyl chloride, polyvinyl acetate,
Vinyl chloride-vinyl acetate copolymer, polyethylene, polypropylene, polyacecool, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, polystyrene, polyacrylic acid ester, polyamide, ethyl cellulose, epoxy resin.

Synthetic rubbers include xylene resin, ketone resin 9 petroleum resin, rosin or its derivatives, coumaron indene resin, terpene resin, polyurethane resin, styrene-butadiene rubber, polyvinyl butyral, nitrile rubber, acrylic rubber, and ethylene-propylene rubber.

In order to provide the cohesive failure layer of the present invention on a substrate, there is a hot melt coating method or, more preferably, a solvent coating method using a coating liquid in which the above compound is dispersed in a medium. In solvent coating, as mentioned above, it is preferable to add 1 to 30% by weight of the thermoplastic resin, and in order to obtain dispersion stability, a commonly used dispersant can also be used. As for the thickness of the cohesive failure layer.

A suitable thickness is 0.2 μm to 3 μm. If it is less than 0.2 μm, the matting effect will be reduced, and if it is more than 3 μm, the total coating thickness will be large.

The cohesive failure layer of the present invention may be a layer colored with a coloring agent of the same color as the hot-melt ink layer.

As the base material used for the thermal transfer material of the present invention, conventionally known base materials can be used. Examples include polyester films (polyethylene terephthalate, polyethylene naphthalate, etc.), polyamide films (nylon, etc.), polyolefin films (polypropylene, etc.), cellulose films (triacetate, etc.), polycarbonate films, and the like. Polyester film has heat resistance 1 mechanical strength and tensile strength.

It is most preferred because of its excellent tensile stability. The thinner the base material is, the better the thermal conductivity is, but from the viewpoint of strength and ease of application of the ink layer, it is most preferably 3 to 50 microns. Further, a back coat layer made of a heat-resistant resin may be provided on the opposite side of the heat-melting ink layer of the base material.

For the heat-fusible ink layer of the present invention, a heat-fusible ink having a conventionally known composition can be used as is.

An example of such an ink is an ink colored with a dye or a pigment using the above-mentioned waxes as a binder agent.

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

In the example, the middle part is the part by weight.

Example 1 A coating liquid with the following composition was sufficiently dispersed in an attritor at room temperature,
An ink for forming a cohesive failure layer was obtained. 6μ of the obtained ink
It was coated onto a polyethylene terephthalate film of 1 µm in thickness by gravure coating.

Lithium stearate (melting point 216℃: industrial purity) 1
Part carnauba wax 19 parts Ethylene-vinyl acetate copolymer (Evaflex 420j manufactured by Mitsui Polychemicals) 1 part Toluene
79 parts Furthermore, a coating liquid having the following composition was applied with three rolls heated to 90 to 120°C.
The mixture was sufficiently kneaded to obtain a hot-melt ink. Next, hot-melt ink was applied onto the cohesive failure layer using a roll coating method to a coating thickness of 5 μm.

A thermal transfer material was obtained.

Carbon (Mitsubishi Carbon rMA-600J) 10 parts Ethylene-vinyl acetate copolymer (same product as above) 5 parts Carnauba wax 26 parts Paraffin wax 59 parts The obtained thermal transfer material was subjected to Beck smoothing temperature 150 seconds using a normal thermal printer. Print solidly on recording paper.

The matting effect on the surface of the transferred material was judged and it was found that a sufficient matting effect was obtained. In addition, excellent character printing can be obtained.
Characters that were easy to read were obtained.

The matting effect of the obtained printed matter was measured using a gloss meter (rGM-3MJ manufactured by Murakami Color Research Institute) at a measurement angle of 60', and the glossiness was 25. - In general, when printing characters, it can be said that a gloss level of 30 or less provides a sufficient matting effect.

Example 2 A heat-sensitive transfer material was made using the following ink for forming a cohesive failure layer and the same heat-melting ink and base material as in Example 1, and the matting effect of the printed matter was evaluated, and the gloss level was 18. Ta.

Composition of ink for forming a cohesively destructive layer 12-Calcium stearate 20 parts Ethyl cellulose 1 part Toluene 55 parts Methyl isobutyl ketone 24 parts Example 3 The following ink for forming a cohesively destructive layer, the same hot-melt ink as in Example 1, and A heat-sensitive transfer material was made using the base material, and the matte effect of the printed matter was evaluated, and the glossiness was 18.

Composition of ink for forming a cohesive failure layer: 20 parts of ethylene bissterolamide, styrene-butadiene-styrene brox copolymer (
Shell Chemical Co. rTR-1184J) 1 part toluene
79 parts Example 4 A thermal transfer material was made using the following ink for forming a cohesive failure layer and the same heat-melting ink and base material as in Example 1, and the matting effect of the printed matter was evaluated, and the gloss level was 9. Met.

Composition of ink for forming a cohesive failure layer NN'-hexamethylene bis-12-hydroxystearamide 20 parts Polyvinyl butyral (Denki Kagaku Kogyo Co., Ltd. Itt300 0-
IJ) 1 part Isopropyl alcohol 79 parts Example 5 An ink having the following composition was kneaded in the same manner as the meltable ink in Example 1, and then rolled coated.

It was coated on a 6 μm polyethylene terephthalate film to a coating thickness of 1 μm. Furthermore, hot-melt ink was applied in the same manner as in Example 1. When the matting effect of the printed matter of the heat-sensitive transfer material thus produced was evaluated, the glossiness was 15.

'Composition of ink for forming CE fracture layer Lithium stearate 10 parts Carnauba wax 26 parts Paraffin wax 59 parts Ethylene-vinyl acetate copolymer (used in Example 1)
Part 5 Example 6 A heat-sensitive transfer material was made using the following ink for forming a cohesive failure layer and the same heat-melting ink and base material as in Example 1, and the matte effect of the printed matter was evaluated, and the gloss level was 7. Met.

Composition of ink for forming a cohesive failure layer Lithium stearate 20 parts Ethylene-vinyl acetate copolymer (used in Example 1)
1 part toluene
79 parts Example 7 A thermal transfer material was made using the following cohesive failure layer forming ink and the same heat-melting ink and base material as in Example 1, and the matte effect of the printed matter was evaluated, and the gloss level was 7. Met.

- Composition of ink for forming a cohesive failure layer Lithium stearate IO parts Elnapa wax 10 parts Ethylene-8
Acid vinyl copolymer (used in Example 1)
1 part toluene
79 parts Comparative Example 1 The hot-melt ink of Example 1 was applied onto polyethylene terephthalate to a thickness of 5 μm by roll coating. When evaluated in the same manner as in Example 1, the glossiness was 40.
Met. The transferred printed matter had gloss and was clearly difficult to read compared to the printed matter obtained in each example.

(Operations and Effects of the Invention) In the heat-sensitive transfer material of the present invention, a cohesive failure layer is formed between the base material and the heat-meltable ink layer. During thermal transfer, the thermal head in contact with the back surface of the substrate generates heat in response to an electrical signal, and the heat-melting ink layer in that area is transferred to the recording material in a molten state, forming a printed matter. On this occasion.

The part of the cohesive failure layer that corresponds to printing is destroyed inside the layer.

It is transferred together with the hot-melt ink, and a broken surface with irregularities appears on the surface of the printed matter. For this reason, the light rays are diffusely reflected on the uneven surface of the printed matter, producing a matte effect.

As described above, in the thermal transfer material of the present invention, a layer containing an inorganic filler is provided on the surface of the substrate on which the heat-melting ink layer is formed, thereby providing a layer having an uneven surface.

A matte effect can be obtained without directly forming an uneven surface on the surface of the base material by sandblasting or the like.

Therefore, the cost for forming an uneven surface is reduced, sufficient matte printing can be obtained with a cohesive failure layer of 1 micron or less in thickness, and therefore, the decrease in sensitivity due to the provision of the layer is also extremely small. . Also.

The matting effect is superior to that of the prior art described above, and the degree of matting can be easily controlled by changing one composition.

Patent applicant: Toyo Ink Manufacturing Co., Ltd.

Claims (1)

[Scope of Claims] 1. A heat-sensitive transfer material having a heat-fusible ink layer provided on a base material, wherein a layer that causes cohesive failure during thermal transfer is provided between the base material and the heat-fusible ink layer. , the above-mentioned heat-sensitive transfer material characterized by a transfer printed matter having a matte effect. 2. The heat-sensitive transfer material according to claim 1, wherein the cohesive failure layer is a layer containing at least one of a higher fatty acid metal salt, a higher fatty acid amide, or a derivative thereof. 3. The heat-sensitive transfer material according to claim 1, wherein the cohesive failure layer is a layer containing at least one compound selected from higher fatty acid metal salts, higher fatty acid amides, or derivatives thereof, and a thermoplastic resin. 4. The sensitizer according to claim 1, wherein the cohesive failure layer is a layer containing at least one compound selected from higher fatty acid metal salts, higher fatty acid amides, or derivatives thereof, a thermoplastic resin, and a wax. Thermal transfer material. 5. The thermal transfer material according to claims 2 to 4, wherein the higher fatty acid metal salt, higher fatty acid amide, or a derivative thereof has a melting point of 100°C to 300°C.