JPH0532064A - Ink ribbon for sublimate type thermal transfer recording - Google Patents

Abstract

PURPOSE:To provide the subject ink ribbon for sublimate type thermal transfer recording which has durability being durable for high speed transfer recording. CONSTITUTION:In an ink ribbon for sublimate type thermal transfer recording which forms a color material layer 6 containing sublimate dye and a heat resisting sliding layer 8 are formed respectively on both sides of a banded substrate film 4, the substrate film 4 above-mentioned is composed of a polyethylenenaphthalate film to improve the durability.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a sublimation type thermal transfer recording ink ribbon.

[0002]

2. Description of the Related Art Generally, in a thermal transfer recording apparatus, an ink ribbon (thermal transfer sheet) and an image receiving paper formed by providing an ink layer on one surface of a base film, an ink layer of the above ink ribbon and an image receiving layer of the image receiving paper. Are placed so that they face each other, and in this state, the color material of the ink layer of the ink ribbon is transferred to the image receiving paper by heating from the base film side of the ink ribbon with the thermal head. The ink ribbon used in such a thermal transfer recording apparatus includes a sublimation type that uses a heat sublimable dye as a coloring material, and a fusion type that uses a heat melting binder and a pigment as a coloring material. As the base film, a polyethylene terephthalate film which is relatively excellent in heat resistance, smoothness, dimensional stability, mechanical strength, price, etc. is generally used.

[0003]

By the way, in such a thermal transfer system, the printing time largely depends on the time for energizing the heating element of the thermal head. Therefore, in order to shorten the printing time and increase the speed, it is first considered to shorten the energization time to such a thermal head. However, if the energization time is shortened while the voltage applied to the thermal head is kept constant, the amount of heat generated by the heating element of the thermal head naturally decreases, and as a result, the recording density decreases. Therefore, in order to prevent this decrease in recording density,
It is necessary to increase the voltage applied to the thermal head so as not to reduce the amount of electric power.

However, such a method of supplying a relatively large amount of electric power in a short time has a large thermal load on the ink ribbon, and when the ink ribbon is wrinkled during recording or is very serious. , The ink ribbon may be damaged. All of these phenomena cause defects in the recorded image. As described above, in high-speed transfer recording, in order to obtain a high recording density, it is necessary to momentarily apply a large amount of heat energy, but at that time, the ink ribbon will be wrinkled. The reason for this is that there is no problem with the slipperiness or heat resistance of the heat resistant slipping layer of the ink ribbon, and the durability of the ink ribbon itself is lacking, and it is even more durable for increasing the transfer speed. Ink ribbon development is strongly desired.

The present invention focuses on the above problems,
It was created to solve this effectively. An object of the present invention is to provide a sublimation type thermal transfer recording ink ribbon having durability that can endure high speed transfer recording.

[0006]

In order to solve the above-mentioned problems, the present invention has a coloring material layer containing a sublimable dye on one surface of a base film and a heat-resistant lubricity on the other surface. In the sublimation type thermal transfer recording ink ribbon having a layer, the base film is made of a polyethylene naphthalate film.

[0007]

Since the present invention is constituted as described above, in order to obtain high-speed recording and high-density recording, the durability of the ink ribbon base film itself is sufficient even if a large amount of energy is momentarily applied. , There are wrinkles in the ink ribbon,
It is possible to prevent damage.

[0008]

EXAMPLES An example of a sublimation type thermal transfer recording ink ribbon according to the present invention will be described below with reference to the accompanying drawings.
FIG. 1 is an enlarged sectional view of a main part of an ink ribbon according to the present invention. As shown in the figure, the ink ribbon 2 has a coloring material layer 6 which is an ink layer containing a sublimable dye on one surface of a base film 4 formed in a strip shape, and a heat resistant slipping layer 8 on the other surface.
Are formed respectively.

In the conventional ink ribbon, a polyethylene terephthalate film or the like is used as the base film 2 of the ink ribbon. This polyethylene terephthalate film was the most easy to use in terms of heat resistance, smoothness, dimensional stability, mechanical strength, variety of types, cost and the like. However, in the thermal transfer recording method for achieving higher speed recording as described above, heat resistance, dimensional stability during heating, and mechanical strength were insufficient. Therefore, in order to obtain high-speed recording and high-density recording, an ink ribbon substrate film that is sufficiently durable even when a large amount of heat energy is momentarily applied is required. As a result of various studies as a base film satisfying such requirements, the present inventor has found that a polyethylene naphthalate film is optimal.

This polyethylene naphthalate film has a high glass transition temperature of 100 ° C. or more and high heat resistance, and has a large Young's modulus of about 1000 kg / mm ² . As these, those commercially available can be used. The base film 4 has a high thermal conductivity and a high sensitivity when the thickness is as thin as possible, but the mechanical strength is lowered when the thickness is too thin. Therefore, in this embodiment, the thickness of the base film 4 is set within the range of 1 to 20 μm, preferably 3 to 10 μm in order to satisfy both of these.

The color material layer 6 comprises a sublimable dye as a color material and resins as a binder, or additives such as an antistatic agent and a dispersant. Examples of sublimable dyes include azo type, anthraquinone type, naphthoquinone type and styryl type dyes, which are selected in consideration of color developability, durability, compatibility with binder resin and the like. The binder resin used for the color material layer of the thermal transfer recording ink ribbon has compatibility with dyes, heat resistance,
It is selected in consideration of printability, solubility, ease of handling, and the like.

The heat resistant slipping layer 8 formed on the other surface of the thermal transfer recording ink ribbon 2 is selected from the following viewpoints. (1) It is possible to completely prevent heat fusion with the ink ribbon. (2) The running property of the ink ribbon can be secured. (3) Do not let dirt adhere to the thermal head. (4) The dye does not transfer even when stored in a wound state. (5) A uniform coating film can be obtained. The composition is determined in consideration of these and is formed on the base film 4. The present inventor has already filed Japanese Patent Application No. 1-276664.
No. 7 proposed a heat resistant slipping layer of an ink ribbon for thermal transfer recording. Here, as the composition of the heat resistant slipping layer, an ultraviolet curable resin composition containing an ultraviolet curable resin as a main component and a photopolymerization initiator, a diluent or the like added thereto, and an ultraviolet curable silicone resin as a lubricant, It consists of pigments.

As the ultraviolet curable resin, commercially available monofunctional, bifunctional acrylate or trifunctional or higher functional polyfunctional acrylate can be used. Examples thereof include neopentyl glycol diacrylate, trimethylolpropane triacrylate, dipentaerythritol hexaacrylate, and the like. Further, a photopolymerizable oligomer (prepolymer) can also be used. Examples of these oligomers include epoxy acrylate, polyester acrylate, polyurethane acrylate, polyether acrylate, oligo acrylate, alkyd acrylate, and polyol acrylate.
Since these oligomers generally have high viscosity, they need to be diluted when they are coated on a base film by a well-known coating method such as a gravure coater or a reverse coater. In that case, it is diluted with a general solvent such as methyl ethyl ketone or toluene, or with a monomer called a reactive diluent. Examples of this monomer include 2-hydroxyethyl acrylate,
There are 2-hydroxypropyl acrylate, 1,3 butanediol diacrylate, diethylene glycol diacrylate and the like.

Further, a photopolymerization initiator for causing an ultraviolet curing reaction is added. This is general and there is no particular problem. Examples of the photopolymerization initiator include self-cleaving benzyl dimethyl ketal (trade name: Irgacure-651), benzoin, benzoin alkyl ether, and the like. Alternatively, a hydrogen abstraction type benzophenone, benzyl, or the like may be used. The addition amount of the photopolymerization initiator is usually 0.1 to 10 parts by weight. Further, the addition amount of the ultraviolet curable silicone resin as a lubricant is appropriately 0.1 to 10 parts by weight with respect to 100 parts by weight of the ultraviolet curable resin composition. The thickness of the heat resistant slipping layer 8 in the present invention is usually 0.1 to 10 μm, preferably 0.1 to 10 μm.
It is 3 μm.

By constructing the ink ribbon 2 as described above, the durability of the ink ribbon itself can be greatly improved, and high-speed transfer recording can be performed without lowering the recording density, wrinkling or damage to the ribbon. It became possible to do. Hereinafter, more specific examples of the present invention will be described.

Example 1 A polyethylene naphthalate film having a thickness of 6 μm was used as a base film 4 of an ink ribbon for sublimation type thermal transfer recording, and an ink composition as shown below was gravure-coated on one surface of the base film 4. Printing was performed with a printing machine and hot air drying at 80 ° C. was performed to form the color material layer 6. At the same time, a heat resistant slipping layer composition as shown below was applied to the other surface of the base film 4 using a gravure coater to form a heat resistant slipping layer 8. And
After being dried in a drying oven, it was cured by irradiation with a high pressure mercury lamp (80 W / cm, irradiation distance 10 cm).

<Composition of color material layer> Kayaset Blue 714 (sublimable dye) 5 parts by weight Linear saturated polyester resin 1 part by weight Cellulose acetate propionate 4 parts by weight Silicon fine particles (particle size 2 μm, spherical) 0. 5 parts by weight Silicone modified acrylic resin 0.1 parts by weight Methyl ethyl ketone 49.4 parts by weight Toluene 40 parts by weight

<Heat-resistant slip layer composition> 16 parts by weight of polyester acrylate (M-6300 manufactured by Toagosei Kagaku) Neopentyl glycol diacrylate (NPGDA manufactured by Nippon Kayaku) 16 parts by weight benzyl dimethyl ketal (manufactured by Ciba Geigy, Irga Cure 651) 1.5 parts by weight UV curable silicone resin 1.5 parts by weight Calcium carbonate 2 parts by weight Toluene (diluting solvent) 63 parts by weight

Comparative Example 1 All were prepared under the same conditions as in Example 1 except that a polyethylene terephthalate film 6 μm thick which was conventionally used as a base film of an ink ribbon was used. In order to evaluate the sublimation type thermal transfer recording ink ribbons of Example 1 and Comparative Example 1 thus obtained, an image receiving paper for thermal transfer recording was prepared. A synthetic paper (manufactured by Oji Yuka Synthetic Paper) having a thickness of 150 μm was used as a substrate of the image receiving paper for thermal transfer recording, and the following composition was applied onto the substrate of the image receiving paper so that the film thickness after drying was 10 μm. It was painted with a blade. And after coating, 100 ℃
Then, heat treatment was performed for 10 minutes to obtain an image receiving paper.

<Composition of Image Receiving Layer> Linear saturated 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 In order to evaluate the ink ribbons of Example 1 and Comparative Example 1 thus obtained, energizing conditions can be changed. Printer output device (compatible with sublimation type, having a thermal head with a heating resistor density of 12 dot / mm) is used to perform thermal transfer recording using the above-mentioned image receiving paper, and to check the wrinkles and damages occurring on the ink ribbon and the recording density. The results are shown in Table 1 below.

[0021]

[Table 1]

Here, in Table 1 above, the following points are shown. (1) The printing time represents the total printing time of A4 size three colors. (2) PEN in the column of substrate film represents a polyethylene naphthalate film. PET in the column of (3) substrate film represents a polyethylene terephthalate film. (4) The O mark in the wrinkle / damage column indicates that no wrinkles have occurred, the Δ mark indicates that wrinkles have occurred, and the X mark indicates that the ribbon has broken.

As shown in Table 1, in Example 1, a high-quality recorded image was obtained without wrinkles on the ink ribbon during high-speed transfer recording, while Comparative Example 1
, Wrinkles were observed, and the ink ribbon was damaged during high-speed transfer recording.

[0024]

As described above, according to the ink ribbon for thermal transfer recording of the present invention, it is possible to prevent the occurrence of wrinkles in the ink ribbon during thermal transfer recording, and it is possible to obtain a high quality recorded image. .. As a result, the sublimation type thermal transfer recording type printer output device has an effect that it can be put to practical use while taking advantage of its features.

[Brief description of drawings]

FIG. 1 is an enlarged partial sectional view showing a sublimation type thermal transfer recording ink ribbon according to the present invention.

[Explanation of symbols]

2 ... Ink ribbon, 4 ... Base film, 6 ... Color material layer, 8
... Heat resistant slipping layer.

Claims (1)

Claim: What is claimed is: 1. A sublimation-type thermal transfer recording ink ribbon having a coloring material layer containing a sublimable dye on one surface of a substrate film and a heat resistant slipping layer on the other surface thereof. An ink ribbon for sublimation thermal transfer recording, wherein the base film is made of a polyethylene naphthalate film.