JPH04265796A - Ink ribbon for thermal transfer recording - Google Patents

Abstract

PURPOSE:To prevent the sticking of the resin applied to the substrate of an ink ribbon to a thermal head at the time of transfer recording or the generation of wrinkles in the ink ribbon. CONSTITUTION:Inorg. or org. fine particles 3 are added to the colorant layer formed to one surface of a substrate 1. Otherwise, an ultraviolet curable resin composition containing an ultraviolet curable silicone resin having an acryloyl or methacryloyl group as a functional group and fine resin particles is used as the heat-resistant lubricating layer formed to the other surface of the substrate 1.

Description

Description: FIELD OF INDUSTRIAL APPLICATION This invention relates to an ink ribbon for thermal transfer recording. [0002] A thermal transfer recording device is a thermal transfer recording device in which an ink ribbon (thermal transfer sheet) with an ink layer provided on one surface of a substrate and an image receiving paper are superimposed so that the ink layer faces the image receiving paper. The color material in the ink layer of the ink ribbon is transferred to the image-receiving paper by heating it from the side with a thermal head. Ink ribbons used in such thermal transfer recording devices include sublimation type ink ribbons that use heat-sublimable dyes as coloring materials, and melt-type ink ribbons that use heat-melting binders and pigments as coloring materials. By the way, if the base of the ink ribbon does not have sufficient heat resistance, the base will be fused to the thermal head, causing a so-called sticking phenomenon, making it impossible for the ink ribbon to run. Therefore, a means to solve this problem was developed in JP-A-55-74.
No. 67, JP-A-56-155794, and JP-A-59-196291. [0004] The content disclosed in JP-A No. 55-7467 is that a heat-resistant protective layer made of silicone, fluorine, epoxy resin, etc. is provided on the surface of the substrate that comes into contact with the thermal head; The content disclosed in JP-A-59-196291 is that a heat-resistant protective layer made of a thermosetting resin containing inorganic particles such as talc is provided on the surface of the base that contacts the thermal head, and the content disclosed in JP-A-59-196291 is , a heat-resistant protective layer made of a polymer composition containing a lubricant or a surfactant is provided on the surface of the substrate that comes into contact with the thermal head. [Problems to be Solved by the Invention] However, in the case of an ink ribbon provided with a heat-resistant protective layer as described above,
Although the heat resistance and runnability are improved to some extent, there are the following problems. (1) In order to obtain a high recording density, it is necessary to apply a large amount of thermal energy, but the heat resistance disclosed in JP-A-55-7467 is insufficient in terms of heat resistance. Further, during storage while winding the ink ribbon, the coloring material in the coloring material layer is likely to be transferred to the heat-resistant protective layer that is in direct contact with the coloring material layer. (2) In order to ensure runnability against large thermal energy, Japanese Patent Laid-Open No. 5
When the lubricant component is increased as disclosed in Japanese Patent No. 9-196291, the lubricant component is scraped off by the thermal head and deposited as dirt on the head. Furthermore, since lubricants generally have poor compatibility with other resins, it is difficult to obtain a uniform coating film. (3) As disclosed in JP-A-56-155794, when the heat-resistant protective layer contains inorganic pigments such as calcium carbonate, silica, talc, etc., these become the surface protective layer of the thermal head. (wear-resistant layer) and significantly reduces the durability of the thermal head. (4) In addition, all of the prior art techniques focus on only one side of the ink ribbon, that is, the side that contacts the thermal head, but even if only one side is improved, the wrinkles of the ink ribbon that occur during transfer recording will be reduced. cannot be prevented. That is, the wrinkles of the ink ribbon require good lubricity between the heat-resistant protective layer and the thermal head, and at the same time, good lubricity between the ink layer and the image-receiving paper. Means for Solving the Problems In order to solve the above-mentioned problems, the invention according to claim 1 contains inorganic or organic fine particles in the coloring material layer, and the invention according to claim 2 contains heat-resistant slippery particles. The layer (heat-resistant protective layer) was formed from an ultraviolet curable resin composition containing an ultraviolet curable silicone resin having an acryloyl group or a methacryloyl group as a functional group and organic fine particles. [0011] In the ink ribbon according to claim 1, the inorganic or organic fine particles contained in the coloring material layer control the slipperiness between the ink ribbon and the dyed layer of the image-receiving paper, thereby preventing wrinkles from forming in the ink ribbon. Therefore, when a large amount of thermal energy is applied for high-density recording, no burden is placed on the heat-resistant slippery layer of the ink ribbon. [0012] Furthermore, in the ink ribbon of claim 2,
Since fine resin particles are used instead of inorganic pigments, the surface protective layer of the thermal head can be prevented from being damaged, and the durability of the thermal head can be improved. [0013] Examples of 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 to which the invention of claim 1 is applied, and FIG. 2 is an enlarged sectional view of a main part of an ink ribbon to which the invention of claim 2 is applied. First, the ink ribbon IR shown in FIG. 1 has a color material layer (ink layer) 4 containing a sublimable dye formed on one side of an ink ribbon base 1, and a heat-resistant slipping layer 2 on the other side. However, the ink layer 4 contains fine particles 3. As the ink ribbon substrate 1, polyethylene terephthalate film, polyimide film, polypropylene film, polyamide film, etc. can be used. Among these, polyethylene terephthalate film has heat resistance, smoothness, dimensional stability, mechanical strength,
It is the easiest to use in terms of variety, price, etc. The thickness of the substrate 1 is generally 1 to 20 .mu.m, preferably 3 to 10 .mu.m from the viewpoint of mechanical strength, although the thinner the substrate 1, the better the thermal conductivity and the more sensitive the ink ribbon will be. The ink layer 4 is composed of a sublimable dye as a coloring material, a resin as a binder, additives such as an antistatic agent and a dispersant, and inorganic or organic fine particles 3. Sublimable dyes include azo, anthraquinone, naphthoquinone, and styryl dyes, and are selected in consideration of color development, durability, compatibility with the binder resin, and the like. The binder resin is selected in consideration of compatibility with the dye, heat resistance, printability, solubility, ease of handling, etc. Among the inorganic or organic fine particles 3 contained in the ink layer 4, general inorganic fine particles can be used. For example, calcium carbonate, titanium oxide, talc, silica, alumina, etc. can be used. Further, as the organic fine particles, silicone resin fine particles, fluororesin fine particles, acrylic resin fine particles, benzoguanamine resin fine particles, polyethylene fine particles, etc. can be used. Further, the inorganic fine particles and the organic fine particles may be used alone or in combination. Furthermore, the particle size of the fine particles 3 to be added is 0.0
Use a material of about 1 to 10 μm, preferably 1 to 5 μm
shall be. In addition, the shape of the fine particles is acicular, spherical, flaky,
Any shape such as cubic, columnar, irregular shape, etc. can be used, but the shape has a large influence on the properties and is selected from the viewpoint of controlling the slipperiness between the dyed layer of the image-receiving paper and the ink layer of the ink ribbon. There is a need. The amount added is influenced by the composition of the dyed layer of the image receiving paper and the composition of the ink layer, but is, for example, about 0.01 to 20%, preferably about 0.01 to 10%, based on the ink layer composition. . The heat-resistant slipping layer 2 can completely prevent thermal adhesion with the thermal head, ensure the running properties of the ink ribbon, prevent dirt from adhering to the thermal head, and can be stored in a rolled state. The composition is selected taking into consideration that the dye will not transfer and that a uniform coating film will be obtained. The composition used as the heat-resistant slipping layer 2 includes an ultraviolet curable resin composition containing an ultraviolet curable resin as a main component, to which a photopolymerization initiator, a diluent, etc. are added, and an ultraviolet curable silicone as a lubricant. A material consisting of a resin and a pigment can be used. As the ultraviolet curable resin composition, for example, monofunctional acrylate, bifunctional acrylate, or polyfunctional acrylate of trifunctional or higher functionality can be used. Examples include neopentyl glycol diacrylate, trimethylolpropane triacrylate, dipentaerythritol hexaacrylate, and the like. Alternatively, a photopolymerizable oligomer (prepolymer) can be used. Examples of oligomers include epoxy acrylate, polyester acrylate, polyurethane acrylate, polyether acrylate, oligoacrylate,
Examples include alkyd acrylate and polyol acrylate. [0021] When these oligomers are used, since they generally have high viscosity, it is necessary to dilute them when coating onto a substrate using a well-known coating method such as a gravure coater or a reverse coater. In that case, it is diluted with a common solvent such as methyl ethyl ketone or toluene, but it may also be diluted with a monomer called a reactive diluent. Examples include 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 1,3-butanediol diacrylate, diethylene glycol diacrylate, and the like. A photopolymerization initiator is also added to cause an ultraviolet curing reaction. This is common and poses no particular problem. For example, self-cleavable benzyl dimethyl ketal (trade name: IRGACURE-651), benzoin, benzoin alkyl ether, etc. can be mentioned. There are also hydrogen abstracting types such as benzophenone and benzyl. The amount of photopolymerization initiator added is usually 0.1 to 10 parts by weight. The amount of the ultraviolet curable silicone resin as a lubricant is 0.1 to 10 parts by weight per 100 parts by weight of the ultraviolet curable resin composition. The thickness of the heat-resistant slipping layer 3 in the present invention is usually 0.1 to 10 μm, preferably 0.1 to 3 μm. [0024] Specific examples will be explained below. Example 1 A polyethylene terephthalate film (Tetron film manufactured by Teijin) with a thickness of 6 μm was used as the ink ribbon substrate 1. The following (a) ink composition was printed on one side of the substrate 1 using a gravure printing machine, and the ink composition was printed at 80°C. Dry with hot air. At the same time, the following heat-resistant slipping layer composition (b) was coated on the other surface of the substrate 1 using a gravure coater, and after drying in a drying oven, the composition was coated with a high-pressure mercury lamp (80 W/cm, irradiation distance 10 cm).
The ink ribbon was produced by irradiating and curing the ink. (a) Ink composition Kayaset Blue 714 (sublimable dye)...5 parts by weight linear saturated polyester resin...
1 part by weight Cellulose acetate propionate...4
Part by weight Silicone fine particles (particle size 2 μm, spherical)…0.5
Part by weight Methyl ethyl ketone
...49.5 parts by weight toluene
...40 parts by weight (b) Heat-resistant slipping layer composition polyester acrylate...
16 parts by weight (manufactured by Toagosei Chemical Co., Ltd., product name: M-6300)
Neopentyl glycol diacrylate...16 parts by weight (
Nippon Kayaku, product name: NPGDA) Benzyl dimethyl ketal...
1.5 parts by weight (manufactured by Ciba Geigy, product name: Irgacure-651) UV-curable silicone resin
...1.5 parts by weight calcium carbonate
...2.0 parts by weight toluene (diluent) ...6
3 parts by weight Examples 2 to 7 The same procedure as in Example 1 was carried out except that in place of the silicone fine particles in the ink composition of Example 1, other fine particles were added as shown in Table 1. An ink ribbon was produced. Comparative Example 1 An ink ribbon was produced in the same manner as in Example 1 using an ink composition in which the silicone fine particles in the ink composition of Example 1 were not added. In order to evaluate the ink ribbons of Examples 1 to 7 and Comparative Examples described above, image receiving papers for thermal transfer recording were prepared. As the image receiving paper medium, synthetic paper (manufactured by Oji Yuka Synthetic Paper) 1
Using a thickness of 50 μm, the following composition was coated onto this substrate using a doctor blade so that the film thickness after drying was 10 μm, and then heat treated at 100° C. for 10 minutes. Image receiving layer composition 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 0031
] Then, the ink ribbons of Examples 1 to 7 and Comparative Example 1 were placed in a printer output device (compatible with sublimation type, 8 dots/
Thermal transfer recording was performed using the above-mentioned image-receiving paper using a thermal head (having a thermal head with a heating resistor density of mm), and the state of wrinkles occurring on the ink ribbon was examined. The results (Table 1)
Shown below. [0032] As is clear from Table 1, the ink ribbons of Examples 1 to 7 do not wrinkle the ink ribbon during transfer recording, and high-quality recorded images can be obtained. On the other hand,
The ink ribbon of the comparative example is prone to wrinkles and streaks appear in the recorded image. Next, in the ink ribbon shown in FIG. 2, a color material layer (ink layer) 12 containing a sublimable dye is formed on one surface of an ink ribbon base 11, and a heat-resistant slipping layer 13 is formed on the other surface. are doing. The substrate 11 and the ink layer 12 can be the same as the ink ribbon shown in FIG. 1, but the ink layer 12 is not limited to one containing inorganic or organic fine particles. The composition used as the heat-resistant lubricant layer 13 includes an ultraviolet curable resin composition containing an ultraviolet curable resin as a main component, to which a photopolymerization initiator, a diluent, etc. are added, and a UV curable resin composition as a lubricant. A resin made of ultraviolet curable silicone resin and fine resin particles is used. The ultraviolet curable resin composition and the ultraviolet curable silicone resin are as explained in connection with the above ink ribbon. As the resin particles, silicone resin particles, fluororesin particles, acrylic resin particles, benzoguanamine resin particles, polyethylene particles, etc. can be used, and the particle size is preferably about 0.01 to 10 μm. is 1 to 5 μm. Next, a specific example will be explained. Example 8 An ink ribbon was produced in the same manner as in Example 1 using the ink composition shown below (c) and the heat-resistant slipping layer composition shown below (d). (c) 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 (d) Heat-resistant slipping layer composition polyester acrylate
...16 parts by weight (manufactured by Toagosei Chemical Co., Ltd., product name: M-6
300) Neopentyl glycol diacrylate
...16 parts by weight (Nippon Kayaku, trade name: NPGDA) benzyl dimethyl ketal
...1.6 parts by weight (manufactured by Ciba Geigy, product name: Irgacure-651) UV-curable silicone resin
...1.6 parts by weight Silicone resin fine particles (particle size 2 μm, spherical) ...0.8 parts by weight Toluene (diluent)
...64 parts by weight Example 9 In place of the silicone resin fine particles in the heat-resistant slipping layer composition (d) of Example 8, a heat-resistant slipping layer composition using fluororesin fine particles (particle size 3 μm) was used. An ink ribbon was produced in the same manner as in Example 1. Comparative Example 2 Calcium carbonate (particle size 2 μm, irregular shape,
An ink ribbon was produced in the same manner as in Example 1 using a heat-resistant slipping layer composition using 1.2 parts by weight of toluene (63 parts by weight of toluene). Comparative Example 3 Titanium oxide (particle size: 1 μm, irregular shape,
An ink ribbon was produced in the same manner as in Example 1 using a heat-resistant slipping layer composition using 2 parts by weight of toluene (63 parts by weight of toluene). The ink ribbons of Examples 8 and 9 and Comparative Examples 2 and 3 were then printed using a printer output device (compatible with sublimation type, equipped with a thin film thermal head with a heat generating resistor density of 8 dots/mm). Thermal transfer recording was performed using image-receiving paper, and various characteristics were investigated. The results are shown in (Table 2). In addition, in the same table, damage to the thermal head was determined by observing the surface of the thermal head under a microscope after printing 1000 screens to confirm scratches and the like. [0044] [Table 2] [0045] As is clear from Table 2, the ink ribbons of Examples 8 and 9 have well-balanced characteristics.
In contrast, the ink ribbons of Comparative Examples 2 and 3 had minute scratches on the surface protective layer of the thermal head, streak-like unevenness occurred in the recorded images, and The cured film of the heat-resistant slipping layer was scraped off due to minute scratches, causing stains on the thermal head. Effects of the Invention As explained above, according to the invention of claim 1, since the colorant layer contains inorganic or organic fine particles,
These fine particles can control the lubricity between the ink ribbon and the dyed layer of the image receiving paper, preventing wrinkles from forming on the ink ribbon. It does not put a burden on the layers. Further, according to the second aspect of the invention, since fine resin particles are used in the heat-resistant slipping layer, there is no damage or stain to the thermal head, and deterioration of the thermal head can be prevented and high durability can be ensured. Thereby, uneven recording density can be prevented.

[Brief explanation of the drawing]

[Fig. 1] Enlarged cross-sectional view of main parts of an ink ribbon to which the present invention is applied

[Fig. 2] Enlarged cross-sectional view of main parts of an ink ribbon according to another embodiment

[Explanation of symbols]

1, 11... Ink ribbon substrate, 2, 13... Heat-resistant slipping layer,
3...Fine particles.

Claims (2)

[Claims] 1. An ink ribbon for thermal transfer recording having a coloring material layer containing a sublimable dye on one surface of a substrate and a heat-resistant slipping layer on the other surface, wherein the coloring material layer contains inorganic or organic fine particles. An ink ribbon for thermal transfer recording characterized by: 2. An ink ribbon for thermal transfer recording having a coloring material layer containing 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 has an acryloyl group or a methacryloyl group. An ink ribbon for thermal transfer recording, comprising an ultraviolet curable resin composition containing an ultraviolet curable silicone resin having a functional group and organic fine particles.