JPH06171248A - Thermal transfer sheet - Google Patents

Abstract

PURPOSE:To provide a thermal transfer sheet having a good heat-resistant slip layer excellent in heat resistance, film forming properties or slip properties, improving the running properties of a thermal head and preventing the accumulation of refuse on the thermal head and the abrasion of the thermal head. CONSTITUTION:In a thermal transfer sheet wherein a thermal transfer colorant layer is formed on one surface of a base material sheet and a heat-resistant slip layer is formed on the other layer thereof, the heat resistant slip layer is composed of a silicone segment-containing resin and/or an ionizing radiation crosslinked matter of a mixture of a silicone segment-containing monomer and a multifunctional monomer.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a thermal transfer sheet, and more particularly to a novel thermal transfer sheet having an excellent heat resistant slipping layer made of a specific material.

[0002]

2. Description of the Related Art Conventionally, as a thermal transfer sheet, a sublimation type thermal transfer sheet having a dye layer composed of a sublimable dye and a binder provided on one surface of a polyester film or the like, and a pigment and a wax instead of the dye layer are used. A heat-melting type thermal transfer sheet provided with an ink layer is known. These thermal transfer sheets are heated imagewise from the back side by a thermal head to transfer the dye of the dye layer or the ink layer to the transfer material to form an image.

[0003]

When an image is formed by the thermal head using the thermal transfer sheet, the thermal head is heated to a high temperature when the base material film is a thermoplastic film such as a polyester film. However, there is a problem that the thermal head is fused to the base material film, the good running property of the thermal head is hindered, and the thermal transfer sheet is damaged or wrinkled. As a method of solving these problems, a method of forming a back layer made of a heat-resistant resin on the contact surface of the thermal head is known, but the heat-resistant resin does not reduce the sensitivity to such an extent that it does not lower the sensitivity. It is difficult to form a thin film. Even if the thermal head can be formed, the thermal head does not have sufficient slip properties, and the running performance of the thermal head cannot be satisfied. On the other hand, it is also known to form a slip layer using silicone oil or silicone wax, but since these silicone oils and waxes have low film strength and low adhesion to the base sheet, a thermal head that runs There is a problem in that good printability cannot be obtained because the shavings are scraped off and accumulated in the thermal head as slag.

Further, for the purpose of solving the above problems, a method of forming a heat resistant slipping layer using an ultraviolet curable silicone or a silicone graft acrylic resin has been proposed (see Japanese Patent Laid-Open No. 128288/1990). According to the method, the heat resistant slipping layer has a low crosslink density, and sufficient heat resistance cannot be obtained.
As a similar method, the method described in JP-A-61-143195 is known, but the heat resistance of the heat resistant slipping layer formed by this method is insufficient. Further, a method of adding silica powder or the like having good lubricity to the heat-resistant back layer is also known, but in this case, there is a problem that the wear of the thermal head becomes severe. Therefore, the object of the present invention is to
To provide a thermal transfer sheet having excellent heat resistance, film-forming property, slip property, etc., good running property of the thermal head, and having a good heat-resistant slipping layer which prevents slag from being accumulated on the thermal head and abrasion of the thermal head. Is.

[0005]

The above object can be achieved by the present invention described below. That is, the present invention is a thermal transfer sheet in which a heat transferable color material layer is formed on one surface of a substrate sheet, and a heat resistant slipping layer is formed on the other surface, wherein the heat resistant slipping layer is a silicone segment-containing resin. And / or a thermal transfer sheet comprising an ionizing radiation cross-linked product of a mixture of a silicone segment-containing monomer and a polyfunctional monomer.

By forming the heat resistant slipping layer of the thermal transfer sheet from the ionizing radiation cross-linked product of the silicone segment-containing resin and / or the mixture of the silicone segment-containing monomer and the polyfunctional monomer, the coating property and the slip property can be obtained. And so on,
There is provided a thermal transfer sheet having a good heat-resistant slipping layer, which has a good running property of the thermal head, and in which the slag is not accumulated on the thermal head and the thermal head is not worn.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in more detail with reference to the preferred embodiments. The base sheet used in the thermal transfer sheet of the present invention may be any one as long as it has a conventionally known degree of heat resistance and strength,
For example, paper having a thickness of about 0.5 to 50 μm, preferably about 3 to 10 μm, various processed papers, polyester film, polystyrene film, polypropylene film, polysulfone film, PEN film, PCT film, P
The PS film, the aramid film, the polycarbonate film, the polyvinyl alcohol film, the cellophane, etc. are particularly preferable, and the polyester film is particularly preferable. These substrate sheets may be of single-wafer type or continuous film, and are not particularly limited. Among these, polyethylene terephthalate film is particularly preferable, and it is also preferable to form a primer layer or an adhesive layer on one side or both sides of the film, if necessary.

The heat resistant slipping layer formed on one surface of the above base sheet is formed from an ionizing radiation crosslinked product of a silicone segment containing resin and / or a silicone segment containing monomer. As the silicone segment-containing resin, silicone-modified polyester resin, polyacrylic ester resin, polyvinyl acetate resin, styrene acrylate resin, polyurethane resin, polyolefin resin, polystyrene resin, polyvinyl chloride resin , Polyether resin, polyamide resin, polycarbonate resin, polyethylene resin, polypropylene resin, polyacrylate resin, polyacrylamide resin,
Polyvinyl chloride resin, polyvinyl butyral resin,
Thermoplastic resins such as polyvinyl acetal resins such as polyvinyl acetoacetal resins are used, and particularly preferable silicone-modified resins among these are polyvinyl butyral resins modified with silicone and polyvinyl acetal resins such as polyacetoacetal resins. Further, the amount of the silicone segment in these silicone-modified resins is preferably in the range of 1 to 30% by weight in the modified resin. If the content of the silicone segment is too small, the slipperiness will be insufficient, while if it is too large, the coatability will deteriorate.

In the present invention, the silicone segment-containing monomer is a reactive silicone oil having an acryloyl group or a vinyl group bonded thereto. Examples of reactive silicone oils include epoxy-modified, amino-modified, carboxyl-modified, alcohol-modified, epoxy-modified
Examples of the modified silicone oil include polyether-modified and polyether-modified silicone oils. More specifically, the following reactive silicones can be mentioned.

[0009]

[Chemical 1]

In the above formula, R _{1 to} R ₅ are mainly methyl groups, but may be alkyl groups other than methyl groups, phenyl groups and the like. Further, l, m, n, x and y are integers of 1 or more which are appropriately set depending on the molecular weight, and the atomic groups of the l and n parts are randomly copolymerized. In order to retain the polymerizable double bond in the reactive silicone oil as described above, carboxyl group, amino group, hydroxyl group,
A (meth) acrylic acid derivative or a vinyl compound having a reactive group such as an isocyanate group or an epoxy group may be reacted. As another silicone compound, a hydrogen polydimethylsiloxane or vinyl polydimethylsiloxane in which at least one of R _{1 to} R _{6 in} the following formula is a hydrogen atom or a vinyl group can be used.

[Chemical 2]

In a preferred embodiment of the present invention, the silicone segment-containing resin and / or the silicone segment-containing monomer are added to the heat-resistant slipping layer for the purpose of imparting heat resistance, coatability and adhesion to a substrate. It is preferable to use a functional monomer together. As such a polyfunctional monomer, for example, as a preferable monomer, tetraethylene glycol di (meth) acrylate {(meth) acrylate means both acrylate and methacrylate. The same shall apply hereinafter}, divinylbenzene, diallyl phthalate, etc. 2
Functional monomers, triallyl isocyanurate, trifunctional monomers such as trimethylolpropane tri (meth) acrylate, tetramethylolmethane tetra (meth) acrylate, trimethoxyethoxyvinylsilane, etc., and 5 represented by the following formula: Examples thereof include functional monomers and oligomers and oligomers and macromers composed of these monomers. Four
It is particularly preferable to use a monomer having a functionality or higher.

[Chemical 3]

The amount of the polyfunctional monomer used is appropriately in the range of 5 to 30 parts by weight per 100 parts by weight of the silicone segment-containing resin and / or silicone segment-containing monomer. If the ratio of the monomers used or the number of functional groups is too low, the heat resistance of the heat resistant slipping layer to be formed is insufficient, and problems such as fusion of the thermal head during printing and scraping of the heat resistant slipping layer occur. On the other hand, if the use ratio is too large, the crosslinking density and the heat resistance are improved, but on the other hand, the deformation such as curling due to curing shrinkage becomes severe, which causes wrinkling of the thermal transfer sheet, which is not preferable. Further, in the present invention, when forming a heat resistant slipping layer from the above materials, a heat release agent or a lubricant such as wax, higher fatty acid amide, ester or surfactant is used for the purpose of improving the slip property of the heat resistant slipping layer. An organic powder such as an antistatic agent or a fluororesin, and inorganic particles such as clay and talc can be included. Further, in order to improve the antistatic property of the resulting thermal transfer sheet, an antistatic agent such as a surfactant or a conductive agent such as carbon black may be added. To form the heat resistant slipping layer, the above materials are dissolved or dispersed in an appropriate solvent such as acetone, methyl ethyl ketone, toluene, xylene to prepare a coating solution, and the coating solution is gravure coater or roll coater. It is formed by coating and drying it by a conventional coating means such as a wire bar, and then performing a crosslinking treatment with ionizing radiation.

The amount of coating, that is, the thickness of the heat resistant slipping layer is also important, and in the present invention, the solid content is 5.0 g / m ² or less,
Preferably, the heat resistant slipping layer having sufficient performance can be formed with a thickness of 0.1 to 1.0 g / m ² . It is also effective to form a primer layer made of polyester resin, polyurethane resin or the like prior to forming the heat resistant slipping layer. The above-mentioned cross-linking and hardening of the coating layer can be hardened by either ultraviolet rays or electron beams or both, but it is preferable to harden it by electron beams to obtain a cross-linked product in consideration of the hardening speed, cross-linking density and the like. . In the case of an electron beam, it may be irradiated from any surface of the coating layer,
The conventional technology can be used as it is as an irradiation device, for example, in the case of electron beam curing, Cockloft-Walton type, Van de Graaff type, resonance transformation type, insulating core transformer type, linear type, electro curtain type, dynamitron type, high frequency 50 to 100 emitted from various electron beam accelerators such as molds
An electron beam having an energy of 0 KeV, preferably 100 to 300 KeV is used, and the irradiation dose is preferably about 1 to 5 Mrad.

As the coloring material layer formed on one surface of the base sheet, a layer containing a sublimable dye is formed in the case of a sublimation type thermal transfer sheet, while in the case of a heat melting type thermal transfer sheet. Forms a wax ink layer colored with a pigment.
The case of a sublimation type thermal transfer sheet will be described below as a typical example, but the present invention is not limited to the sublimation type thermal transfer sheet. As the dye used in the dye layer, any of the dyes used in conventionally known thermal transfer sheets can be effectively used in the present invention and is not particularly limited. For example, some preferred dyes include MS Red as a red dye.
G, Macrolex Red Violet R, CeresRed7B, Samaron Red H
BSL, Resolin Red F3BS and the like, and yellow dyes such as Holon Brilliant Yellow 6GL, PTY-52, Macrolex Yellow 6G and the like, and blue dyes such as Kayaset Blue 714 and Waxolin. Blue AP-F
W, Holon Brilliant Blue SR, MS Blue 100, etc.

Preferred examples of the binder resin for carrying the above dyes include cellulose resins such as ethyl cellulose, hydroxyethyl cellulose, ethyl hydroxy cellulose, hydroxypropyl cellulose, methyl cellulose, cellulose acetate, and cellulose acetate butyrate, and polyvinyl resins. Alcohol, polyvinyl acetate,
Examples include vinyl resins such as polyvinyl butyral, polyvinyl acetal, and polyvinylpyrrolidone, acrylic resins such as poly (meth) acrylate and poly (meth) acrylamide, polyurethane resins, polyamide resins, polyester resins, and the like. Among them, cellulose-based, vinyl-based, acrylic-based, polyurethane-based, polyester-based resins and the like are preferable from the viewpoints of heat resistance, dye migration, and the like.

The dye layer is prepared by dissolving one of the above-mentioned base sheets and the above-mentioned dye and binder, if necessary, with additives such as a release agent, dissolved in a suitable organic solvent. Or a dispersion dispersed in an organic solvent or water,
For example, it can be formed by applying and drying by a forming means such as a gravure printing method, a screen printing method, and a reverse roll coating method using a gravure plate. The dye layer thus formed has a thickness of about 0.2 to 5.0 μm, preferably about 0.4 to 2.0 μm, and the sublimable dye in the dye layer contains 5% by weight of the dye layer. Suitably it is present in an amount of ˜90% by weight, preferably 10 to 70% by weight. The dye layer to be formed is formed by selecting one color from the above dyes when the desired image is a mono color image, and when the desired image is a full color image, for example, a suitable cyan, magenta and Yellow (and optionally black) is selected to form yellow, magenta and cyan (and optionally black) dye layers.

The image-receiving sheet used for forming an image using the above-mentioned thermal transfer sheet may be any image-receiving sheet as long as its recording surface has dye receptivity to the above-mentioned dye, and Paper, metal, which does not have dye receptivity
In the case of glass or synthetic resin, a dye receiving layer may be formed on at least one surface thereof. In the case of a heat-melting type heat transfer sheet, the material to be transferred is not particularly limited, and may be ordinary paper or a plastic film.
A known thermal transfer printer can be used as it is as a printer used when performing thermal transfer using the thermal transfer sheet and the image receiving sheet as described above, and is not particularly limited.

EXAMPLES Next, the present invention will be described more specifically with reference to Reference Examples, Examples and Comparative Examples. In the text, parts and% are based on weight unless otherwise specified.

Reference Example 1 Isocyanate-modified silicone (molecular weight 3,
000) 10 parts was dissolved in 630 parts of an equal mixed solvent of methyl ethyl ketone and toluene, and then 260 parts of 2-hydroxyethyl methacrylate was gradually added dropwise to 60 ° C.
And reacted for 5 hours to obtain a silicone segment-containing monomer. Reference Example 2 180 parts of hexamethylene diisocyanate is dissolved in 630 parts of an equal mixed solvent of methyl ethyl ketone and toluene, and then 10 parts of the above-mentioned alcohol-modified silicone (molecular weight 2,000) is gradually added dropwise, and the mixture is heated at 60 ° C. for 2 hours. After the reaction, 260 parts of 2-hydroxyethyl methacrylate was gradually added dropwise and reacted at 60 ° C. for 5 hours to obtain a silicone segment-containing monomer. Example 1 Ink for heat resistant slipping layer: Silicone modified polyvinyl butyral resin (silicone segment content 10%) 100 parts Polyfunctional monomer (6 functional, Kayarad DPPH, manufactured by Nippon Kayaku) 20 parts Filler (Microace) P-3, made by Nippon Talc) 7 parts Methyl ethyl ketone / toluene (1: 1) 508 parts The above ink was dried on one side of a PET substrate sheet (4.5 μm, made by Diamond foil) using a miya bar * 5 to dry 1 ．
After coating so as to have a thickness of 0 μm, it was dried with warm air and further subjected to a crosslinking curing treatment by irradiation with an electron beam under the conditions of an accelerating voltage of 175 KeV and 3 Mrad to form a heat resistant slipping layer. Next, the following ink for forming a dye layer was applied to the opposite surface of the heat resistant slipping layer by gravure printing so as to have a dry thickness of 1.0 g / m ² and dried to obtain a thermal transfer sheet of the present invention. Ink for forming a dye layer: CI Solvent Blue 22 5.50 parts Acetoacetal resin 3.00 parts Methyl ethyl ketone 22.54 parts Toluene 68.18 parts

Example 2 A thermal transfer sheet of the present invention was obtained in the same manner as in Example 1 except that the ink having the following composition was used in place of the ink for heat resistant slipping layer in Example 1 (of the heat resistant slipping layer). Thickness = 1 μm). Ink for heat resistant slipping layer: Silicone modified polyvinyl butyral resin (silicone segment content 30%) 100 parts Polyfunctional monomer (6 functional, Kayarad DPPH, manufactured by Nippon Kayaku) 30 parts Filler (Microace P-3 , Manufactured by Nippon Talc) 8 parts Methyl ethyl ketone / toluene (1: 1) 550 parts Example 3 The ink having the following composition was used in place of the ink for the heat resistant slipping layer in Example 1, and the same as in Example 1 except for the above. A thermal transfer sheet of the present invention was obtained (thickness of heat resistant slipping layer = 1 µm). Ink for heat resistant slipping layer: Silicone-modified polyvinyl butyral resin (silicone segment content 30%) 100 parts Silicone-modified monomer of Reference Example 1 30 parts Polyfunctional monomer (6-functional, Kayarad DPPH, Nippon Kayaku) 40 parts Filler (Microace P-3, manufactured by Nippon Talc) 10 parts Methyl ethyl ketone / toluene (1: 1) 720 parts

Example 4 A heat transfer sheet of the present invention was obtained in the same manner as in Example 1 except that the ink having the following composition was used in place of the ink for heat resistant slipping layer in Example 1 (of the heat resistant slipping layer). Thickness = 1 μm). Ink for heat resistant slipping layer: Silicone-modified polyvinyl butyral resin (silicone segment content 10%) 100 parts Polyfunctional monomer (tetrafunctional, Kayarad DPCA, manufactured by Nippon Kayaku) 30 parts Filler (Microace P-3 , Nippon Talc) 8 parts Methyl ethyl ketone / toluene (1: 1) 550 parts Example 5 The ink of the following composition was used in place of the ink for heat resistant slip layer in Example 1, and other conditions were the same as in Example 1. A thermal transfer sheet of the present invention was obtained (thickness of heat resistant slipping layer = 1 µm). Ink for heat-resistant slipping layer: Silicone-modified polyvinyl butyral resin (content of silicone segment : 10%) 100 parts Polyfunctional monomer (6-functional, Kayarad DPPH, manufactured by Nippon Kayaku) 30 parts Filler (Microace P-3 , Nippon Talc) 8 parts Antistatic agent (Atre-4000, manufactured by Nippon Mining Industry) 13 parts Methyl ethyl ketone / toluene (1: 1) 600 parts

Example 6 Silicone-modified polyvinyl butyral resin (content of silicone segment 5%) 100 parts Silicone-modified monomer of Reference Example 30 30 parts Polyfunctional monomer (6-functional, Kayarad DPPH, manufactured by Nippon Kayaku) 40 parts Filler (Microace P-3, manufactured by Nippon Talc) 10 parts Antistatic agent (Atre-400, manufactured by Nippon Mining Industry) 18 parts Methyl ethyl ketone / toluene (1: 1) 720 parts

Comparative Example 1 A thermal transfer sheet of Comparative Example was obtained in the same manner as in Example 1 except that the ink having the following composition was used in place of the ink for the heat resistant slipping layer in Example 1 (of the heat resistant slipping layer). Thickness = 1 μm). Ink for heat resistant slipping layer: Silicone-modified polyvinyl butyral resin (content of silicone segment 10%) 100 parts Filler (Microace P-3, manufactured by Nippon Talc) 6 parts Methyl ethyl ketone / toluene (1: 1) 424 parts Comparative Example 2 A thermal transfer sheet of a comparative example was obtained in the same manner as in Example 1 except that the ink having the following composition was used instead of the ink for heat resistant slipping layer in Example 1 (thickness of heat resistant slipping layer = 1 μm). Ink for heat resistant slipping layer: Silicone modified polyvinyl butyral resin (silicone segment content 5%) 100 parts Silicone modified monomer of Reference Example 2 30 parts Filler (Microace P-3, manufactured by Nippon Talc) 8 parts Methyl ethyl ketone / toluene (1: 1) 550 copies

The above-mentioned thermal transfer sheet is superposed on a conventionally used thermal transfer sheet, and transfer is performed using a transfer recording device under the following transfer conditions, whereby the thermal head and the thermal transfer sheet are fused and wrinkles are generated, and the dye is transferred. Sex (60 ℃, 17g /
m ² for 3 days) and low surface efficiency (Ω / mouth, 500 V applied, 25.5 ° C., 62% RH) were examined and the results are shown in Table 1 below.
Shown in. Transfer conditions : pulse width: 1 ms Recording period: 2.0 ms / line Recording energy: 3.0 J / cm ²

[0024]

【table 1】 Evaluation method: Generation of fusion and wrinkles: By visual observation. Dye transferability: By visual observation. ○: No transition. Δ: Some migration is observed. ◯: Significant transition.

[0025]

[Effects] According to the present invention as described above, the heat resistant slipping layer of the thermal transfer sheet is formed from the ionizing radiation cross-linked product of the silicone segment-containing resin and / or the mixture of the silicone segment-containing monomer and the polyfunctional monomer. By doing so, a thermal transfer sheet having excellent film-forming property, slipping property, etc., good running property of the thermal head and having a good heat-resistant slipping layer which prevents slag from being accumulated on the thermal head and abrasion of the thermal head is provided. It Also, in a preferred embodiment,
By crosslinking the silicone segment-containing resin and / or the silicone segment-containing monomer with a polyfunctional monomer, the heat resistance of the heat resistant slipping layer is further improved in addition to the above-mentioned effects.

Claims (3)

[Claims] 1. A thermal transfer sheet having a heat transferable color material layer formed on one surface of a base sheet and a heat resistant slipping layer formed on the other surface, wherein the heat resistant slipping layer comprises a silicone segment-containing resin and And / or a thermal transfer sheet comprising an ionizing radiation cross-linked product of a mixture of a silicone segment-containing monomer and a polyfunctional monomer. 2. The thermal transfer sheet according to claim 1, wherein the polyfunctional monomer has four or more functional groups. 3. The thermal transfer sheet according to claim 1, wherein the heat resistant slipping layer contains an antistatic agent.