JPH07314921A - Ink sheet for heat transfer recording - Google Patents

Abstract

PURPOSE:To improve durability of a thermal head, and to realize heat transfer recording with high quality by forming a heat-resistant slippage layer consisting of a curable coating film wherein an UV-curable resin compsn. contg. an anti- static UV-curable resin is a main ingredient on one face of a base of an ink sheet for heat transfer recording. CONSTITUTION:In an ink sheet used for heat transfer recording formed of a base 1, a heat-resistant slippage layer 2 and a coloring material layer 3, the heat-resistant slippage layer 2 for preventing heat fusion from occurring is provided on one face of the base 1 and the coloring layer 3 contg. a sublimation dye is provided on another face. In addition, the heat-resistant slippage layer 2 is a curable coating film wherein an UV-curable resin compsn. contg. an anti-static UV-curable resin is a main ingredient. As the result, as the surface electric resistance of the ink sheet can be suppressed, it is possible to decrease adhesion of dust and rubber on the ink sheet surface caused by generation of static electricity. It is possible thereby to keep recording with high quality of image.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal transfer recording ink sheet having an antistatic cured coating film.

[0002]

2. Description of the Related Art What is thermal transfer recording using an ink sheet?
An ink sheet provided with a color material layer (ink layer) on one surface of a substrate is superposed so that the ink layer and the image receiving paper face each other, and the ink is heated by a thermal head from the substrate side of the ink sheet. The color material of the ink layer of the sheet is transferred to the image receiving paper.

Ink sheets used in such thermal transfer recording include a sublimation type using a heat sublimable dye as a coloring material and a melting type using a heat-fusible binder and a pigment as a coloring material. .

Regarding the sublimation type and melting type ink sheets,
If the heat resistance of the ink sheet is not sufficient, the substrate will be fused to the thermal head, causing a so-called stick phenomenon, making the ink sheet unable to run and damaging the thermal head. Therefore, in order to eliminate the above-mentioned stick phenomenon, a heat-sensitive transfer material having a heat-resistant protective layer made of silicone, fluorine, epoxy resin or the like provided on the surface of a substrate contacting the thermal head (JP-A-55-7).
No. 467), a heat-sensitive transfer material having a heat-resistant protective layer made of a thermosetting resin containing inorganic particles such as talc on the surface of a substrate in contact with a thermal head (JP-A-56-155794).
And a thermal recording layer having a heat-resistant protective layer made of a polymer composition containing a lubricant or a surface-active agent on the surface of a substrate in contact with a thermal head (JP-A-59-1962).
No. 91 publication) was proposed.

Particularly, in the transfer material for heat-sensitive recording disclosed in JP-A-59-196291, a lubricant / surfactant added to a polymer composition as a photocurable resin is used to prevent static electricity. Therefore, there is a drawback that the heat resistance is lower than that of the present invention described later.

[0006]

However, in the thermal transfer recording ink sheet provided with the above heat-resistant protective layer, the heat resistance and the running property are improved to some extent, but there are still the following problems. . (1) In order to obtain a high recording density, heat resistance against heat when a large amount of heat energy is applied to an ink sheet is not sufficient. (2) When the ink sheet and the image receiving paper are conveyed in close contact with each other for thermal transfer recording, when the ink sheet and the image receiving paper are peeled off after recording, the ink sheet is easily charged,
Impurities such as dust and dirt tend to adhere. Due to the adhesion of the impurities, the recorded image is lost or the surface protection layer (wear-resistant layer) of the thermal head is damaged, and the durability of the thermal head is reduced.

Thus, the above-mentioned Japanese Patent Laid-Open No. 55-746.
No. 7, JP-A-56-155794 and JP-A-59-196291 have various problems, and it has been desired to develop an ink sheet for thermal transfer recording which solves the problems.

[0008]

In order to solve the above problems, the present invention provides an ink sheet for thermal transfer recording having the following constitution.

In an ink sheet used for thermal transfer recording formed of a substrate, a heat resistant slipping layer, and a coloring material layer,
A heat resistant slipping layer for preventing heat fusion is provided on one surface of the substrate, and a coloring material layer containing a sublimable dye is provided on the other surface, and the heat resistant slipping layer is an antistatic UV curable type. An ink sheet for thermal transfer recording, comprising a cured coating film containing an ultraviolet curable resin composition containing a resin as a main component.

[0010]

EXAMPLE FIG. 1 is a diagram for explaining a main portion of an ink sheet for thermal transfer recording according to the present invention, and FIG. 2 is a diagram for explaining a comparison result of an ink sheet A and an ink sheet B. First, as shown in FIG. 1, a thermal transfer recording ink sheet according to the present invention comprises a color material layer (ink layer) 3 having a sublimable dye on one surface of a substrate 1 and a heat resistant slipping layer 2 on the other surface. Are formed.

As the substrate 1, a polyethylene terephthalate film, a polyimide film, a polyethylene naphthalate film, a polypropylene film, a polyamide film, an aramid film or the like is used. In particular, the polyethylene terephthalate film has heat resistance, smoothness, dimensional stability and mechanical properties. It is the easiest to use in terms of stability, variety, and price.

As for the substrate 1, the heat conductivity is good and the sensitivity is high when the substrate 1 is as thin as possible.
A thickness of -20 μm, preferably 3-10 μm is optimal. The ink layer 3 is composed of a sublimable dye as a coloring material and resins as a binder or additives such as an antistatic agent and a dispersant.

The sublimable dyes include azo type, anthraquinone type, naphthoquinone type and styryl type dyes, which are selected in consideration of color developability, durability and compatibility with binder resin. The binder resin is selected in consideration of compatibility with dyes, heat resistance, printability, solubility, ease of handling, and the like.

That is, the heat resistant slipping layer 2 has heat resistance capable of completely preventing heat fusion (stick phenomenon) with the thermal head, and ensures the running property of the ink sheet.
Furthermore, the composition as described below is selected in consideration of low surface electric resistance so that impurities such as dust and dirt do not adhere.

The composition of the heat resistant slipping layer 2 is based on an ultraviolet curable resin composition containing an antistatic ultraviolet curable resin, a photopolymerization initiator and a diluent, and further an additive such as a lubricant. Use the added one.

As the antistatic UV-curable resin, a polyether dielectric is used as a main chain with an inorganic filler dissolved therein. The content of antistatic UV curable resin is
It is 5 to 100%, preferably 10 to 50% in the ultraviolet curable resin composition. As the inorganic filler, metal oxides such as tin oxide and indium oxide are used. Even if this ultraviolet curable resin is used alone, other ultraviolet curable resins (for example, epoxy acrylate,
Oligo acrylates such as urethane acrylate and polyester acrylate, and other polyfunctional acrylates)
It may be mixed with.

The cured film of the ultraviolet curable resin composition used in the present invention upon irradiation with ultraviolet rays forms a dense cross-linked film having a three-dimensional structure, and therefore has a particularly heat resistant film.

When the ultraviolet curable resin composition is diluted, it may be diluted with a general solvent such as methyl ethyl ketone or toluene, or may be diluted with a monomer called a reactive diluent. In addition, since a UV curing reaction occurs after the dilution, for example, a photopolymerization initiator such as benzyl dimethyl ketal, benzoin, benzophenone or benzyl is usually added in an amount of 0.1 to 10% by weight.

Examples of the lubricant added to secure the running property include liquid lubricants such as silicone lubricants and phosphate ester lubricants, solid lubricants such as organic resin fine particles,
There are inorganic pigments and the like, and specifically, as the silicone-based lubricant, a silicone-modified compound of an acrylic resin or a polyester resin, a modified silicone compound such as amino-modified or epoxy-modified, a silicone oil, a silicone varnish or the like can be used. Examples of the organic resin fine particles include silicone resin fine particles, fluororesin fine particles, acrylic resin fine particles, and polyethylene resin fine particles. These liquid lubricants and solid lubricants may be used alone or may be mixed. The additive is 0.1 to 50% by weight, preferably 0.5 to 20% by weight, based on the heat resistant slipping layer composition.

Next, specific examples of the thermal transfer recording ink sheet according to the present invention will be described.
Using a polyethylene terephthalate film (Tetoron film manufactured by Teijin; thickness of 6 μm), one surface of the substrate 1 was coated with the following heat resistant slipping layer composition by a gravure coater and dried in a drying oven, and then a high pressure mercury lamp (80 W) was used. / Cm, irradiation distance 10 cm) and cured. The content of the heat resistant slipping layer composition is as follows: (1) Epoxy acrylate ------------- 40 parts by weight (Kyoeisha Oil and Fat, epoxy ester 3002A) (2) Antistatic oligomer ----- 25 parts by weight (Daiichi Kogyo Seiyaku Co., Ltd., GX-8352B) (3) Neopentyl glycol diacrylate ----- 15 parts by weight (NPGDA, NPGDA) (4 ) Benzyl dimethyl ketal ---------- 4 parts by weight (Ciba Geigy, Irgagure 651) (5) 1 part by weight of silicone-modified acrylic resin ---------- Shin-Etsu Chemical, X-24-3544) (6) Fluororesin fine particles ------------- 1 part by weight (Nippon Bulker, UNON P) (7) Toluene (diluting solvent) ----- −−−−−−−−− 14 parts by weight And above The following ink composition was applied to the surface of the ink sheet coated with the heat resistant slipping layer composition on the side opposite to the surface of the substrate 1 by a gravure coater to form a thermal transfer recording ink sheet (ink sheet A) of the present invention. obtain. The content of the ink composition is as follows: (1) Kayastable-714 ------------- 5 parts by weight (Nippon Kayaku, sublimation dye) (2) Polyvinyl butyral resin --- 5 parts by weight (manufactured by Sekisui Chemical Co., Ltd., BX-5) (3) Methyl ethyl ketone --------------- 30 parts by weight (4) Toluene ----- ------------- 30 parts by weight (5) Cyclohexanone ------------- 30 parts by weight Next, the heat resistant slipping layer composition described above. An ink sheet for examination (ink sheet B) was prepared by coating the heat resistant slipping layer composition of (2) containing no antistatic oligomer. Then, thermal transfer recording was performed to evaluate the ink sheet A coated with the heat resistant slipping layer composition containing the antistatic oligomer and the ink sheet B coated with the heat resistant slipping layer composition containing no antistatic oligomer. I made the image receiving paper. As the image-receiving paper substrate, synthetic paper (manufactured by Oji Yuka Synthetic Paper) having a thickness of 150 μm was used, and the following image-receiving layer composition was coated on a doctor blade so that the film thickness after drying would be 10 μm.
A heat treatment (10 minutes) at 00 ° C. was performed to obtain an image receiving paper. The content of the image-receiving layer composition is (1) linear saturated polyester resin ---------- 22 parts by weight (2) silicone oil ---------- -1 part by weight (3) Titanium oxide --------------- 1 part by weight (4) Methyl ethyl ketone --------------- 38 Parts by weight (5) Toluene ------------------ 38 parts by weight And, by using the ink sheet A and the ink sheet B and the image receiving paper, sublimation type thermal transfer recording Thermal transfer recording was performed with the device and the characteristics were examined. The result is shown in FIG.

In the figure, the head damage and the head dirt are confirmed by observing the surface of the thermal head with a microscope after printing 1000 screens, and the damage such as scratches and the adhesion of dust, dust, etc. are respectively confirmed. If not, it is represented by ○.

As shown in FIG. 2, the surface electric resistance value of the heat resistant slipping layer surface was measured to be 3 × 10 ¹¹ Ω for the ink sheet A, whereas it was measured to be 10 ¹⁵ Ω for the ink sheet B. That is, the surface electric resistance value of the ink sheet A was suppressed by about 3,000 times or more as compared with the ink sheet B.

Further, from the results shown in the figure, compared with the ink sheet B, the ink sheet A is less likely to have dirt, dust, etc. attached due to the static electricity generated on the ink sheet, so that the thermal head of the thermal transfer recording apparatus is contaminated. Since this can be prevented, deterioration of the thermal head can be prevented, durability of the thermal head can be maintained, and high-quality thermal transfer recording can be performed.

[0024]

As described above, according to the constitution of the present invention described in the claims, the ultraviolet curable resin containing the antistatic ultraviolet curable resin on one surface of the substrate of the ink sheet used for thermal transfer recording. By forming a heat-resistant slip layer consisting of a cured coating film containing the composition as a main component, the surface electric resistance of the ink sheet can be suppressed, so that the adhesion of dust and dust to the surface of the ink sheet due to the generation of static electricity is reduced. It becomes possible to do. That is, the effect of being able to maintain the durability of the thermal head and to realize high-quality thermal transfer recording by suppressing damage to the thermal head for thermal transfer recording and head contamination due to the adhesion of dust and dirt. There is.

[Brief description of drawings]

FIG. 1 is a diagram for explaining a main part of a thermal transfer recording ink sheet according to the present invention.

FIG. 2 is a diagram for explaining a comparison result of an ink sheet A and an ink sheet B.

[Explanation of symbols]

 1 substrate 2 heat resistant slipping layer 3 color material layer (ink layer)

Claims (1)

[Claims] 1. An ink sheet used for thermal transfer recording, comprising a substrate, a heat resistant slipping layer and a coloring material layer, wherein a heat resistant slipping layer for preventing heat fusion is provided on one surface of the substrate. A colorant layer containing a sublimable dye is provided on the other side together, and the heat resistant slipping layer is a cured coating film containing an ultraviolet curable resin composition containing an antistatic ultraviolet curable resin as a main component. An ink sheet for thermal transfer recording, which is characterized in that