JPH0679978A - Ink ribbon for thermal transfer recording - Google Patents

Abstract

PURPOSE:To improve the travelling performance of an ink ribbon for thermal transfer recording and the durability of a thermal head. CONSTITUTION:In an ink ribbon 1, an ink layer 3 having sublimation dye is formed on one surface, i.e., the surface facing a material to be transferred 6 such as card and paper, of a substrate 2. A heat resistant sliding layer 4 is formed on the other surface, i.e., the surface in contact with a thermal head 7. Organic resin particulates 5... are contained in the heat resistant sliding layer 4 as sliding agent.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink ribbon for thermal transfer recording.

[0002]

2. Description of the Related Art In a general thermal transfer recording apparatus, an ink ribbon (thermal transfer sheet) having an ink layer provided on one surface of a substrate and an image receiving paper are superposed so that the ink layer faces the image receiving paper, and the ink ribbon substrate is formed. By heating with a thermal head from the side, the color material of the ink layer of the ink ribbon is transferred to the image receiving paper. Ink ribbons used in such a thermal transfer recording apparatus include a sublimation type that uses a heat sublimable dye as a coloring material and a fusion type that uses a heat-fusible binder and a pigment as a coloring material.

If the heat resistance of the ink ribbon is not sufficient, the substrate is fused to the thermal head to cause a so-called stick phenomenon and the ink ribbon cannot run.
Therefore, as means for solving this, Japanese Patent Laid-Open No. 55-746
No. 7, JP-A-56-155794, JP-A-Sho 5
9-196291 and JP-A-62-259889.
The one disclosed in the publication is proposed.

The contents disclosed in JP-A-55-7467 are those in which a heat-resistant protective layer made of silicone, fluorine, epoxy resin or the like is provided on the surface of a substrate which comes into contact with a thermal head. Japanese Patent Laid-Open No. 59-196 discloses that a heat-resistant protective layer made of a thermosetting resin containing inorganic particles such as talc is provided on the surface of a substrate that contacts a thermal head.
The content disclosed in Japanese Patent No. 291 is that a heat resistant protective layer made of a polymer composition containing a lubricant or an interfacial lubricant is provided on the surface of a substrate that comes into contact with a thermal head, and JP-A-62-259889. The content disclosed in the publication is a laminate of a heat resistant layer made of a cured resin and a heat resistant slip layer made of a reaction product of polyvinyl butyral and isocyanate and an additive.

[0005]

Problems to be Solved by the Invention JP-A-55-7467
In the means disclosed in the publication, the heat resistance when a large amount of heat energy is applied in order to obtain a high recording density is insufficient, and the coloring material in the coloring material layer is not removed during the winding storage of the ink ribbon. The color material layer is easily transferred to the heat resistant protective layer in contact therewith. In the means disclosed in JP-A-56-155794, the inorganic particles such as talc damage the surface protective layer (wear-resistant layer) of the thermal head, significantly reducing the durability of the thermal head. In the means disclosed in Japanese Patent Laid-Open No. 59-196291, when the lubricant component is increased in order to improve the lubricity, the lubricant component is scraped off by the thermal head and deposited and deposited as dirt on the thermal head. Further, a lubricant generally has poor compatibility with other resins and a uniform coating film cannot be obtained. In the means disclosed in JP-A-62-259889, compatibility of the lubricant with other resins need not be taken into consideration, but the ink layer in which the lubricant is in contact with the ink ribbon during winding storage May be transferred to.

[0006]

In order to solve the above problems, the present invention provides a thermal transfer recording having a color material layer containing a pigment or a sublimable dye on one surface of a substrate and a heat resistant slipping layer on the other surface. In the ink ribbon for use, the heat resistant slipping layer is a thermosetting coating mainly composed of a reaction product of a thermoplastic resin having a reactive group and a silicone-modified resin compound having a reactive group, and an isocyanate compound, and a lubricant. As a result, fine particles of organic resin were included.

The material constituting the above-mentioned substrate is polyethylene terephthalate film, polyimide film,
Polyethylene naphthalate film, polypropylene film, polyamide film, aramid film and the like are used. Among them, the polyethylene terephthalate film is the most easy to use due to its heat resistance, smoothness, dimensional stability, mechanical strength, variety of types, price and the like. The thickness of the substrate is preferably as thin as possible so that the ink ribbon has high thermal conductivity and high sensitivity, but from the viewpoint of mechanical strength, it is usually 1 to 20 μm, preferably 3 to 10 μm.
m.

The ink layer contains a sublimable dye as a coloring material,
It comprises resins as binders or additives such as antistatic agents and dispersants. As sublimable dyes, azo-based dyes,
There are anthraquinone type, naphthoquinone type, styryl type and the like, and these are selected in consideration of color developability, durability, compatibility with binder resin, solubility in solvent and the like. The binder resin is selected in consideration of compatibility with dyes, heat resistance, printability, solubility, ease of handling, and the like.

The heat resistant slipping layer can completely prevent thermal fusion with the ink ribbon, ensure the running property of the ink ribbon, do not attach dirt or the like to the thermal head, and can store the dye even when stored in a wound state. The composition is selected in consideration of the fact that there is no transition and that a uniform coating film can be obtained. The composition used as the heat resistant slipping layer is a solvent-melting agent that reacts with an isocyanate compound to form a crosslinkable coating film, for example, a thermoplastic resin having a reactive group such as a hydroxyl group or a carboxyl group in the molecule. In addition to this thermoplastic resin, a silicone-modified resin compound that has a reactive group in the molecule that also reacts with an isocyanate compound in the molecule to impart lubricity to the crosslinkable coating, an isocyanate compound as a crosslinking component, and a lubricant It contains organic resin fine particles and other additives for controlling the properties.

Examples of the thermoplastic resin having a reactive group in the molecule or at the terminal of the molecule include, for example, polyvinyl butyral resin, polyvinyl acetal resin, vinyl chloride-vinyl acetate copolymer, vinyl chloride-acrylic acid ester copolymer or molecule. Examples include linear saturated polyester resins having a hydroxyl group at the terminal. When these solvent-soluble resin compositions are used, they can be coated on a substrate by a well-known coating method such as a gravure coater or a reverse coater.

Examples of the isocyanate compound as the cross-linking agent include trimethylolpropane (TMP) prepared from hexamethylene diisocyanate as a raw material, an adduct type polyisocyanate compound, and an aliphatic isocyanate such as a buret type or trimer type polyisocyanate compound. Or aromatic isocyanates such as tolylene diisocyanate (TDI), 4,4′-diphenylmethane diisocyanate (MDI) and xylylene diisocyanate.

As the organic resin fine particles to be contained as a lubricant, silicone resin fine particles, fluororesin fine particles, acrylic resin fine particles, benzoguanamine resin fine particles, polyethylene fine particles and the like can be applied. Preferably, from the viewpoint of heat resistance of the organic resin fine particles themselves, silicone resin fine particles,
Fluororesin fine particles are used. These organic resin particles 5
May be used alone or as a mixture. Further, the particle size of the organic resin fine particles 4 to be added is about 0.01 to 20 μm, and preferably 1 to 5 μm. The shape of the organic resin fine particles 5 is
There are needles, spheres, flakes, cubes, columns, and irregular shapes, and any of them can be used, but the shape has a great influence on the characteristics, and the thickness of the heat-resistant slip layer and the degree of lubricity are taken into consideration. While you have to choose. The addition amount is affected by the shape of the thermal head and the operating conditions of the thermal transfer recording apparatus, but is, for example, 0.01 to 5 relative to the heat resistant slipping layer composition.
It is 0% by weight, preferably about 0.01 to 20% by weight.

The silicone-modified resin compound, which is the other lubricant used together with the organic resin fine particle lubricant, has a reactive group in the molecule or at the terminal of the molecule and can react with an isocyanate compound.
A resin compound selected from the group of polyester resin and urethane resin is used as a main chain, and a silicone resin is block-polymerized or graft-polymerized with this resin compound. For example, as the silicone-modified acrylic resin, there are X-24-3544, X-24-3547, and X- manufactured by Shin-Etsu Chemical Co., Ltd.
24-3548 (both are trade names) and the like. Examples of the silicone-modified polyester resin include X-24-8301, X-24-8302, and X-24 manufactured by Shin-Etsu Chemical Co., Ltd.
-7870 (both are trade names) and the like, and as the silicone-modified urethane resin, TS-manufactured by Sanyo Kasei Kogyo
400 (trade name) and the like. These are selected from the viewpoints of compatibility with the base resin used and coatability. For example, when a linear polyester resin is used as a base resin as the thermoplastic resin, a silicone-modified polyester resin is most preferable as the silicone-modified resin compound in terms of compatibility. Further, the addition amount is selected in consideration of the running property in the thermal transfer recording apparatus to which it is applied and the adhesion and damage of stains on the thermal head. For example, the addition amount is 0.1 to 5 relative to the heat resistant slipping layer composition.
It is 0% by weight, preferably 0.5 to 20% by weight.

[0014]

In the ink ribbon of the present invention, sufficient heat resistance can be obtained by using a cured film (crosslinked film) formed by heating as a heat resistant slipping layer, and a silicone-modified resin compound and an organic resin are used as lubricants. By using fine particles, sufficient runnability and scratch protection of the surface protection layer of the thermal head can be achieved, and since a silicone-modified resin compound that is compatible with the base resin is used, a uniform coating film can be easily obtained. You can

[0015]

Embodiments of the present invention will be described below with reference to the accompanying drawings. Here, FIG. 1 is an enlarged cross-sectional view of an ink ribbon for thermal transfer recording according to the present invention. The ink ribbon 1 is a sublimable dye on one surface of a substrate 2, that is, a surface facing a transfer target 6 such as a card or paper. The heat resistant slipping layer 4 is formed on the other surface, that is, the surface in contact with the thermal head 7, and the heat resistant slipping layer 4 has organic resin fine particles 5 as a lubricant.
... is included. A part of the organic resin fine particles 5 projects from the heat resistant slipping layer 4.

Specific examples and comparative examples of the present invention will be given below. <Example 1> As the ink ribbon substrate 2, a polyethylene terephthalate film (Tetron film manufactured by Teijin) 6
The heat resistant slipping layer composition (a) below was applied to one surface of the substrate 1 using a gravure coater to a thickness of μm. After drying in a drying oven, it was left in a curing oven at 40 ° C. for 6 days to obtain a crosslinked coating. The coating amount was 1 g / m ² .

(A) Heat resistant slipping layer composition Linear saturated polyester resin: 10 parts by weight (Toyobo: Byron-290) Isocyanate compound: 6 parts by weight (Nippon Polyurethane: Coronate HL) Silicone modified polyester resin: 1 part by weight Parts (Shin-Etsu Chemical Co., Ltd .: X-24-8301) Fluororesin fine particles 1 part by weight (Nippon Bulker: Yunon P) Toluene 41 parts by weight Methyl ethyl ketone 41 parts by weight

Next, the following (b) ink composition was coated on the other surface of the substrate 2 provided with the heat resistant slipping layer with a gravure coater to obtain an ink ribbon.

(B) Ink composition Kayaset Blue 714 (sublimable dye) 5 parts by weight Linear saturated polyester resin 1 part by weight Cellulose acetate propionate 4 parts by weight Methyl ethyl ketone 50 parts by weight Toluene 40 parts by weight

Example 2 An ink ribbon was prepared in the same manner as in Example 1 except that the heat resistant slipping layer composition of Example 1 was replaced with the following heat resistant slipping layer composition (a).

(A) Heat resistant slipping layer composition Polyvinyl butyral resin: 10 parts by weight (Sekisui Chemical: S-REC BX-5) Isocyanate compound: 6 parts by weight (Nippon Polyurethane: Coronate HL) Silicone-modified acrylic resin: 1 part by weight Part (Shin-Etsu Chemical Co., Ltd .: X-24-3544) Fluororesin fine particles 1 part by weight (Nippon Bulker: Yunon P) Toluene 41 parts by weight Methyl ethyl ketone 41 parts by weight

Example 3 Ink was prepared in the same manner as in Example 1 except that polyvinyl acetal resin was used as the base resin and silicone modified acrylic resin was used as the silicone modified resin compound in the heat resistant slipping layer composition of Example 1. A ribbon was made.

Comparative Example 1 An ink ribbon was prepared in the same manner as in Example 1 using the heat resistant slipping layer composition of Example 1 containing no lubricant.

Comparative Example 2 An ink ribbon was prepared in the same manner as in Example 1, except that the heat-resistant slip layer composition containing no silicone-modified resin compound was used as the lubricant in the heat-resistant slip layer composition of Example 1. Was produced.

Comparative Example 3 An ink ribbon was prepared in the same manner as in Example 1, except that the heat-resistant slip layer composition containing no organic resin particles was used as the lubricant in the heat-resistant slip layer composition of Example 1. It was made.

Comparative Example 4 Instead of the organic resin fine particles in the heat resistant slipping layer composition of Example 1, an inorganic pigment (manufactured by Shiraishi Kogyo:
An ink ribbon was produced in the same manner as in Example 1 using the heat resistant slipping layer composition to which calcium carbonate-callite) was added (1% by weight).

Comparative Example 5 In place of the silicone-modified resin compound in the heat resistant slipping layer composition of Example 1, non-reactive dimethyl silicone oil (KF-96 manufactured by Shin-Etsu Chemical) was added (1% by weight). An ink ribbon was prepared in the same manner as in Example 1 using the heat resistant slipping layer composition prepared above.

The above is summarized (Table 1).

[Table 1]

Here, in order to evaluate the ink ribbons of the above Examples and Comparative Examples, a thermal transfer image-receiving paper was prepared. Synthetic paper (made by Oji Yuka Synthetic Paper) 1
A film having a thickness of 50 μm was used, and the following image-receiving layer composition (c) was coated on this substrate with a doctor blade so that the film thickness after drying would be 10 μm, and then heat-treated at 100 ° C. for 10 minutes to prepare the film. .

(C) Image Receiving Layer Composition Linear polyester resin 22 parts by weight Silicone oil 1 part by weight Titanium oxide 1 part by weight Methyl ethyl ketone 38 parts by weight Toluene 38 parts by weight

Then, the ink ribbons of Examples 1 to 3 and Comparative Examples 1 to 5 were printed by a printer output device (corresponding to a sublimation type and having a thin film thermal head having a heating resistor density of 8 dot / mm). Thermal transfer recording was performed using image receiving paper, and various characteristics were examined. The results are shown in (Table 2). In Table 2, the thermal head damage is
After printing 1000 screens, the surface of the thermal head was observed under a microscope to confirm scratches and the like.

[0032]

[Table 2]

As is clear from Table 2, Examples 1 to 1
In the ink ribbon of No. 3, the respective properties are well balanced, and the function as the heat resistant slipping layer is sufficiently fulfilled, whereas in Comparative Examples 1 to 5, sufficient running property cannot be obtained. , It can be seen that the ink ribbon is wrinkled or causes an image defect. Further, in Comparative Example 5, the thermal head had stains. In addition, it is difficult to obtain a uniform coating film because of poor compatibility with the base resin. In Comparative Example 4, fine scratches were formed on the surface protective layer of the thermal head, and streak-like defects were generated in the recorded image.

[0034]

As described above, according to the present invention,
The heat-resistant slipping layer uses a cured film formed by heating, and the lubricant uses a silicone-modified resin compound and organic resin fine particles, so sufficient heat resistance can be obtained, and a large amount of heat energy can be applied for high density recording. Also, the running property of the ink ribbon can be secured and wrinkles do not occur. Further, by containing organic resin fine particles in the heat resistant slipping layer, sufficient running property and scratches and stains on the surface protective layer of the thermal head can be prevented, and durability can be improved and recording density unevenness can be prevented.
Furthermore, since a silicone-modified resin compound having good compatibility with the base resin is used, a uniform coating film can be easily obtained.

[Brief description of drawings]

FIG. 1 is an enlarged sectional view of an ink ribbon for thermal transfer recording according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Ink ribbon 1, 2 ... Substrate, 3 ... Ink layer, 4 ... Heat resistant slipping layer, 5 ... Organic resin fine particles, 6 ... Transferred object.

Claims (3)

[Claims] 1. A thermal transfer recording ink ribbon having a coloring material layer containing a pigment or a sublimable dye on one surface of a substrate and a heat resistant slipping layer on the other surface, wherein the heat resistant slipping layer comprises:
A thermosetting coating containing a thermoplastic resin having a reactive group and a reaction product of a silicone-modified resin compound having a reactive group and an isocyanate compound as a main component, and containing organic resin fine particles as a lubricant. Ink ribbon for thermal transfer recording. 2. The silicone-modified resin compound has a resin compound selected from the group of acrylic resin, polyester resin, and urethane resin as a main chain, and a silicone resin is block-polymerized or graft-polymerized with the resin compound. An ink ribbon for thermal transfer recording according to claim 1. 3. The thermal transfer recording ink ribbon according to claim 1, wherein the organic resin fine particles are silicone resin fine particles and / or fluororesin fine particles.