JPS6351180A - Thermal transfer recording medium - Google Patents

Abstract

PURPOSE:To obtain the transfer picture of high in density and efficient in uniformity and abrasion resistance, by successively establishing a first transfer layer and a second transfer layer having respective specific structures on bearing materials. CONSTITUTION:A first transfer layer consisting of the resin particles having a melting point or a softening point of within a range of 75 to 140 deg.C and the wax having a melting point or a softening point of within a range of 70 to 130 deg.C as main components, and the second transfer layer consisting of dye and /or pigment, the resin particles having a melting point or a softening point of within a range of 60 to 110 deg.C, and the wax having melting point or a softening point of within a range of 70 to 130 o<= as main components are successively established on bearing materials. Generally known polyester film, polyamide film, polyvinyl chloride film, etc. can be used as the bearing material and the inorganic and organic dye and pigment used for printing ink, coating material, etc. can be used as the dye and pigment. Further, for instance acrylic resin, methacrylic resin, styrene resin, etc. are used as the resin used for resin particles, and carnauba wax, polyethylene wax, etc. are used as the wax.

Description

Detailed Description of the Invention [Technical Field] The present invention relates to a thermal transfer recording medium for performing thermal transfer recording on recording paper by utilizing the heat/gravity of an ink layer, and is applicable to printers such as computers, word processors, etc. It can also be applied to code printers, etc.

[Prior Art] A thermal transfer medium is known in which a transfer layer consisting of a heat-fusible substance such as paraffin wax and a coloring agent such as a dye or pigment is provided on a support. Since the strength is weak, there is a disadvantage that the abrasion resistance of the transferred image is poor.

In order to improve this drawback, methods have been taken such as adding thermoplastic resin or making the transfer layer as thin as possible.
The former has the problem that when the resin component increases, the adhesive force becomes strong, making it difficult to transfer, and the thermal sensitivity deteriorates, while the latter has the problem of poor uniformity of the transferred image and a decrease in image density. Ta.

[Purpose] The present invention solves the above-mentioned problems of the prior art, makes it possible to produce 1 q of transferred images with high density and excellent uniformity on recording paper, and also provides transferred images with excellent abrasion resistance and perceptibility. The purpose is to provide such a thermal transfer recording medium.

[Structure] The structure of the present invention for achieving the above object includes a first transfer layer having the following structure (1) and the following (2) on a support.
This is a thermal transfer recording medium which sequentially has a second transfer layer having the following structure.

(1) A first transfer layer mainly composed of resin particles having a melting point or softening point in the range of 75 to 140°C and wax having a melting point or softening point in the range of 70 to 130°C.

(2) A second material whose main components are dyes and/or pigments, resin particles having a melting point or softening point in the range of 60 to 110°C, and wax having a melting point or softening point in the range of 70 to 130°C. Transfer layer.

The transfer layer of the thermal transfer recording medium of the present invention is stacked on a recording paper,
A desired image is formed on the recording paper by thermal printing from the back side of the thermal transfer recording medium.

As the support for the thermal transfer recording medium according to the present invention, various conventionally known supports can be used as appropriate.

Examples of these include plastic films such as polyester film, polyamide film, polyvinyl chloride film, polyethylene film, polypropylene film, polyimide film, borizalft film, and polycarbonate film, and condenser paper.

As the dyes and pigments used in the present invention, inorganic and organic dyes and pigments used in printing inks, paints, etc. can be used. Specific examples include carbon black, Disazo Yellow, Brilliant Carmine 6B, Lake Red C, Phthalocyanine Blue, Kayaset Black KR (Nippon Herbal Medicine), Oil Yellow 3G (Orient Chemical), and Car V.
Set red includes -BE (Japanese Herbal Medicine), Kaya Set Blue KFL (Japanese Herbal Medicine), etc.

As the resin used for the resin particles, various resins having a melting point or softening point (ring and ball method JIS K 2531) of 60 to 140°C can be used.

For example, acrylic resin, methacrylic resin, styrene resin,
Examples include vinyl acetate resin, vinyl chloride resin, vinylidene chloride resin, petroleum resin, novolac resin, olefin resin, polyester resin, polyacetal resin, epoxy prepolymer, or copolymer thereof.

Furthermore, a plasticizer can be used as necessary to adjust the melting point or softening point of the resin particles.

For example, dimethyl phthalate, diethyl phthalate, dibutyl phthalate, dioctyl phthalate, dicyclohexyl phthalate, di-2-ethylhexyl adip-1
and diethylene glycol dibenzoate, butyl stearate, triphenyl phosphate, etc.

If the melting point or softening point of the resin particles used for the first transfer layer is lower than 75°C, the transfer image will be exposed to a high temperature environment (50 to 60°C).
If the temperature is higher than 140°C, it becomes difficult to fix the film sufficiently with energy alone during thermal transfer recording, resulting in poor abrasion resistance. Otherwise, high energy recording is required. Problems arise such as the recording speed becomes slower and the life of the thermal head becomes shorter.

Furthermore, if the melting point or softening point of the resin particles used for the second transfer layer is lower than 60°C, the transfer layer may cause blocking while the thermal transfer recording medium is stored, and if it is higher than 110°C, the transferred image This is not preferable because the uniformity deteriorates.

The resin particles used in the present invention can be made into 1q by micronizing various resins (requires emulsion polymerization, wet dispersion using a sand mill, etc., dry dispersion using a jet mill, etc.).

The average diameter of the resin particles is preferably about 0.1 to 5 μm, particularly about 1 to 3 μm. If it is less than 0.1 μm, sticking will easily occur during transfer, and if it exceeds 5 μm, thermal sensitivity and resolution will deteriorate, which is not preferable.

The wax used in the present invention is suitably one having a melting point or softening point of 70 to 130°C.

If the melting point or softening point of this wax is lower than 70° C., the applied thermal energy is consumed to melt the wax, resulting in insufficient energy to soften the resin. Therefore, only the wax is preferentially transferred, and the transfer of the transfer layer becomes insufficient, causing blurring of the transferred image and deterioration of sharpness. Further, if the temperature is higher than 130° C., high thermal energy is required for transfer.

Further, the penetration degree of such wax is preferably 1 or less, and if the penetration degree is greater than 1, the scratch resistance of the recorded image will decrease.

Specific examples include carnauba wax, polyethylene wax, Finscher-Tropsch wax, monk wax derivatives, and hydrogenated castor oil.

The use of these waxes affects the thermal sensitivity and abrasion resistance of thermally transferred images. The proportion of wax used is preferably 10 to 70% by weight of the total solid content of the transfer layer, and 10% by weight.
If it is less than 70% by weight, a uniform transferred image cannot be obtained, and if it exceeds 70% by weight, the abrasion resistance deteriorates, which is not preferable.

Binder other than wax can be used as appropriate in the transfer layer of the invention, but its use should be kept to the minimum limit that does not inhibit the transfer, and should be 0 to 25% by weight of the total solid content of the transfer layer. That's about it. As these binders, conventional binders can be used, such as polyvinyl alcohol, methoxycellulose, hydroxyedylcellulose, carboxymethylcellulose, polyvinylpyrrolidone, polyacrylamide, starch, gelatin,
Acrylic resin, methacrylic resin, vinyl acetate resin, vinyl chloride resin, vinylidene chloride (H fat, olefin resin,
These include polyester resins or copolymers thereof.

As the recording paper used with the thermal transfer recording medium of the present invention, plain paper, synthetic paper, plastic film, etc. can be used as appropriate.

The thermal transfer recording medium of the present invention is produced by mixing the above-mentioned transfer layer forming components with water or a solvent that does not dissolve the resin particles, and using a dispersing means such as a stirrer, a ball mill, an attritor, etc., the average particle size of the resin particles is reduced to 0.1 to 5 μm. Disperse it on the support so that the total solid content is 1 to 10 g.
/m2 and drying at a temperature below the softening point of the resin particles so as not to fuse the resin particles.

[Example] Next, the present invention will be explained in more detail with reference to Examples. By the way, both ``Part 1'' and ``F%'' shown below are Zhang Chejizhuo.

1. Preparation of carbon black dispersion Carbon black 20 parts Surfactant
2 parts water
78 parts of the material with the above composition in a ball mill
Dispersed for 4 hours.

2. Preparation of Resin Particle Dispersion Table 1 The materials listed in Table 1 above were dispersed in a ball mill for 24 hours to obtain a dispersion G of resin particles with an average particle size of 2 μm.

Examples 1 to 6 Preparation of coating liquid for first transfer layer The compositions listed in Table 2 above were mixed uniformly using a stirrer.

Preparation of coating liquid for second transfer layer Table 3 The compositions listed in Table 3 above were mixed uniformly using a stirrer.

Preparation of thermal transfer recording medium The above coating liquid for the first transfer layer (Table 2) was applied onto a 6 μm thick polyester film using a wire bar so that the applied Wffi after drying was 2 g/m2, and then warm PA ( 40
~50°C).

Next, the coating liquid for the second transfer layer (Table 3) was similarly applied onto the first transfer layer so that the amount of adhesion after drying was 2 g/m2, and dried, so that the first and second transfer layers were coated, respectively. A thermal transfer recording medium was prepared using the combinations listed in Table 4.

Table 4 Comparative Example 1 Application! N0.2 was applied onto a 6 μm thick polyester film so that the amount of adhesion after drying was 4 g/m 2 and dried to produce a thermal transfer recording medium.

Comparative Example 2 A thermal transfer recording medium was prepared using the same coating liquid N0.6 as in Comparative Example 1.

Comparative example 3.4 Table 5 A thermal transfer recording medium of 1 d was prepared in the same manner as in Examples 1 to 6.

The thermal transfer recording medium produced as described above was printed using a thermal transfer printer by applying an energy of 0.5 mJ/dat with the transfer layer brought into close contact with the surface of high-quality paper.

Furthermore, in order to examine the abrasion resistance of the printed image, the abrasion resistance (temperature: 20.50°C) against cardboard was tested using a lab tester (manufactured by Toyosoki Co., Ltd.).

The results were as shown in Table 6 below.

6th surface image 'a Reflection density of the two-edge printing area (Macbeth reflection densitometer) Uniformity: presence or absence of voids (areas where ink is not transferred) in the two-peta printing area...no voids, very bad...・Some voids, bad: Many voids Abrasion resistance: 100 friction cycles, 100g/cm2 Good: No change, slightly bad: A little ink is removed from the printed area, and a little bit sticks to the non-printed areas.・Scratch resistance: A lot of ink is removed from the printed area and a lot of ink is attached to the non-printed area: I rubbed the transferred image with a barcode reading pen scanner and looked at how much ink was removed from the printed area...No change, bad...・Ink is removed from the printed area and attached to the non-printed area [Effect] As explained above, by using the thermal transfer recording medium of the present invention, the ink can be transferred with high density, good uniformity, and excellent abrasion resistance. The image is incremented by 1.

Claims (1)

[Scope of Claims] A thermal transfer recording medium characterized by having, on a support, a first transfer layer having the following configuration (1) and a second transfer layer having the following configuration (2) in sequence. . (1) A first transfer layer whose main components are resin particles whose melting point or softening point is in the range of 75 to 140°C and wax whose melting point or softening point is in the range of 70 to 130°C. (2) A second material whose main components are dyes and/or pigments, resin particles having a melting point or softening point in the range of 60 to 110°C, and wax having a melting point or softening point in the range of 70 to 130°C. Transfer layer.