JPH068640A - Production of sublimation type thermal transfer recording sheet - Google Patents

Abstract

PURPOSE:To prevent the contamination of the opposite surface of a base material due to a heat-resistant slide layer and to solve a problem in the aspect of production and capacity due to contamination by arranging a colorant layer containing a heat-evaporative or heat-diffusible dye on the single surface of the base material and subsequently arranging the heat-resistant slide layer to the opposite surface of the base material. CONSTITUTION:A sublimation type thermal transfer recording sheet is obtained by arranging a colorant layer containing a heat-evaporative or heat-diffusible dye on the single surface of a base material and a heat-resistant slide layer is arranged to the opposite surface of the base material. In this case, the sublimation type thermal transfer recording sheet is produced by arranging the colorant layer containing the heat-evaporative or heat-diffusble dye on the single surface of the base material at first and subsequently arranging the heat-resistant slide layer on the opposite surface of the base material. By this constitution, the contamination of the opposite surface of the base material due to the heat- resistant slide layer is prevented and a problem in the aspect of production and capacity due to contamination is eliminated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a thermal transfer recording sheet, and particularly to a sublimation type thermal transfer recording in which a coloring material layer and a heat resistant slipping layer are respectively applied on both sides of an extremely thin and long base material. Method for improving productivity and stabilizing the performance of final products in the manufacturing process of manufacturing sheets

[0002]

2. Description of the Related Art Conventionally, a color material layer prepared by applying a color material ink in which a heat vaporizable or heat diffusible dye and a resin are dissolved on one surface of an extremely thin and long base material, There is known a sublimation type thermal transfer recording sheet having a heat resistant slipping layer formed by applying a heat resistant slipping layer liquid such as a heat resistant resin and a lubricant on the other surface. These sheets are heated by the heating means such as a thermal head from the surface of the heat-resistant slipping layer, and the heat-vaporizable or heat-diffusible dye is transferred from the color material layer to the image receiving layer of the recording material to obtain a sublimation type thermal transfer recording method. Used.

[0003]

As described in JP-A-60-184883, the method for producing the sublimation type thermal transfer sheet is as follows. It has been considered desirable to provide a material layer. The reason is as follows. In sublimation type thermal transfer recording, the temperature is instantaneously 250 to 300 during thermal transfer recording.
In order to withstand the heat of the thermal head, which is said to reach the limit, it is necessary to impart sufficient heat resistance to the substrate. For that purpose, a heat resistant slipping layer using an ordinary resin material is not sufficient, and a heat resistant slipping layer mainly using a thermopolymerizable or thermosetting material is used. As an example, the above-mentioned JP-A-60 is used.
In the examples, the heat resistant slipping layer is formed by applying a heat resistant slipping layer, followed by heating and curing at 60 ° C. for 20 hours. The long material is
It is usually handled in the rolled state, in which state one side and the other side strongly overlap. Therefore, 60
Even during the heat curing treatment at 20 ° C. for 20 hours, the surface coated with the heat resistant slipping layer and the opposite surface strongly overlap each other. Of course, under this condition, in the sheet coated with the coloring material layer, the dye easily bleeds out from the coloring material layer and easily causes a problem such as contaminating a strongly overlapped portion. Especially in the state of insufficient curing during curing,
Alternatively, this tendency is remarkable when the drying is insufficient, that is, when a large amount of low molecular weight substances are present. If the contamination is large, the performance of the heat resistant slipping layer and the performance of the color material layer are adversely affected. Therefore, it has been considered desirable to apply the heat resistant slipping layer, apply heat treatment to complete the curing and drying, and then apply the coloring material layer.

However, in recent years, as the heat resistant slipping layer, one containing a lubricant such as silicone has been adopted in order to impart lubricity. Therefore, after applying the heat resistant slipping layer, when heat treatment is performed in the state where the base material is wound up, the heat resistant slipping layer strongly overlaps with the opposite surface, that is, the surface to which the coloring material layer is to be applied. Therefore, the surface is contaminated by the heat resistant slipping layer component such as silicone. For this reason, when the color material layer is applied next time, due to the influence of the contamination components, the color material ink is apt not to be applied neatly, and the color material layer cannot be sufficiently adhered to the substrate. These drawbacks include the manufacturing aspect of productivity of the recording transfer sheet, and in the finished product, the coloring material layer and the base material are not sufficiently adhered,
This leads to problems in terms of performance, such as the color material layer peeling from the substrate during transfer recording, or uneven coating appears as unevenness in the image.

As a countermeasure, the above-mentioned JP-A-60-18 is used.
No. 4,883 proposes that fine particles are added to the heat resistant slipping layer to reduce the degree of overlap between the front and back in the rolled state, but this is not an essential solution. The present invention provides a method for producing a sublimation type thermal transfer recording sheet which can solve such problems.

[0006]

That is, according to the present invention, in the production of a sublimation type thermal transfer sheet, a color material layer containing a vaporizable or heat diffusible dye is first provided on one surface of a substrate, and then the opposite is applied. Sublimation type thermal transfer recording sheet characterized by solving the problems in production and performance due to contamination on the opposite surface of the heat resistant slipping layer by enabling the manufacturing process of providing the heat resistant slipping layer on the surface. The manufacturing method will be summarized.

The present invention will be described in detail below. Examples of the substrate used in the present invention include polyethylene terephthalate film, polypropylene terephthalate film, polyamide film, polyaramid film, polyimide film, polycarbonate film, polyphenylene sulfide film, polysulfone film, triacetate film, polypropylene film and the like. Among them, the polyethylene terephthalate film is preferable from the viewpoint of mechanical strength, dimensional stability, heat resistance, price, etc., and a biaxially stretched polyethylene terephthalate film is more preferable. The thickness of these base films is 1 to 30 μm, preferably 2 to 10 μm.

The color material layer in the thermal transfer recording sheet of the present invention may be formed by an ordinary method. For example, a sublimation or heat diffusible dye and a binder resin having good heat resistance are dissolved or dispersed in an appropriate solvent to prepare a color material ink, and this ink is used as a substrate, for example, a reverse roll coater,
It may be applied and dried by a method using a gravure coater, a rod coater, an air doctor coater, a die coater, etc. (for details, see “Coating method” by Yuji Harasaki, published by Maki Shoten 1979).

Examples of the above heat vaporizable or heat diffusible dyes include azo type, anthraquinone type, nitro type, styryl type, naphthoquinone type, quinophthalone type, azomethine type,
Various nonionic dyes such as coumarin type and condensed polycyclic type are used, and as the binder resin, polycarbonate resin, polysulfone resin, polyvinyl butyral resin, phenoxy resin, polyarylate resin, polyamide resin, polyaramid resin, Examples include polyimide resins, polyetherimide resins, polyester resins, acrylonitrile-styrene resins, and cellulosic resins such as acetyl cellulose, methyl cellulose, ethyl cellulose and the like, which may be used alone or in combination. As the solvent, toluene, aromatic solvents such as xylene, methyl ethyl ketone, methyl isobutyl ketone, ketone solvents such as cyclohexanone, ethyl acetate, ester solvents such as butyl acetate, isopropanol, butanol, alcohol solvents such as methyl cellosolve, An ether solvent such as dioxane or tetrahydrofuran, an amide solvent such as dimethylformamide or N-methylpyrrolidone, or the like is used.

In addition to the above-mentioned components, the above-mentioned coloring material ink may contain organic or inorganic non-sublimable particles, a dispersant, an antistatic agent, an antiblocking agent, an antifoaming agent, an antioxidant, if necessary. Additives such as viscosity modifiers can be added. The thickness of the color material layer formed on the substrate is usually 0.1 to 5 μm, preferably 0.3 to 3 μm as a dry film thickness.

The coating method of the heat resistant slipping layer in the thermal transfer recording sheet of the present invention can be carried out by the same method as described for the coating of the color material layer. The coating film thickness is a dry film thickness and is usually 0.1 to 10 μm, preferably 0.3 to 5 μm.
m. As the resin of the heat resistant slipping layer, various curable resins having high heat resistance after film formation are used.
In particular, a substance that is cured by light or the like is preferable. As the curable resin, for example, ethyl cellulose, hydroxyethyl cellulose, cellulose-based resin such as cellulose acetate,
There are vinyl resins such as polyvinyl alcohol, polyvinyl acetate and polyvinyl butyral, phenoxy resins and polycarbonate resins. Radiation-curable resins such as polyester acrylate, polyurethane acrylate, epoxy acrylate, and polyether acrylate are preferable.

Further, for the purpose of enhancing the running property of the heat resistant slipping layer,
Organic or inorganic particles, a commonly known liquid or solid lubricant, etc. are used. Examples of the lubricant include various silicone oils, fluorine-based oils, mineral oils, waxes and phosphate ester-based lubricants. The method of the present invention is particularly useful when a liquid lubricant is used.

In order to prepare a coating solution, the above-mentioned resin, etc. may be used, if necessary, in a suitable solvent, for example, as in the case of the image-receiving layer.
Toluene, aromatic solvents such as xylene, methyl ethyl ketone, methyl isobutyl ketone, ketone solvents such as cyclohexanone, ethyl acetate, ester solvents such as butyl acetate, isopropyl alcohol, butanol, alcohol solvents such as methyl cellosolve, methylene chloride, Halogen-based solvents such as trichlorethylene and chlorobenzene,
Dissolve or disperse in an ether solvent such as dioxane or tetrahydrofuran to prepare a coating solution.

The coating solution for the heat resistant slipping layer containing the radiation curable resin is cured by a usual method such as irradiation with radiation after the coating is dried. Examples of the radiation include ultraviolet rays, electron beams and gamma rays. As a light source when using ultraviolet rays, for example, there is a high pressure mercury lamp or a metal halide lamp having an output of about 30 to 160 w / cm. When an electron beam is used, an electron beam accelerator having an accelerating voltage of 100 to 750 kV is used so that the absorbed dose becomes 2 to 20 Mrad and curing is performed.

Among these arbitrary combinations, particularly the combination using the radiation curable resin, the curing is instantaneously terminated by the irradiation of the radiation, and the heat curing treatment after coating is not required. Suitable for Among them, the combination mainly composed of the ultraviolet curable resin does not require long-time heat treatment after coating, and also enables high-speed treatment, does not require high heat with low energy consumption, and has a simple device. It is most preferable because it has excellent performance such as heat resistance of the coating film. More specifically, it is preferable to use a radical polymerization type acrylic ester resin as the ultraviolet curable resin. Further adjust the viscosity of the coating liquid,
In addition, in order to increase the crosslink density and improve the film strength after curing, it is preferable to use a polyfunctional acrylate monomer in combination. As the polyfunctional monomer, examples of the bifunctional monomer include neopentyl glycol diacrylate and diethylene glycol diacrylate.
Examples of the trifunctional monomer include pentaerythritol triacrylate and trimethylol popan triacrylate, and examples of the tetrafunctional or higher monomer include hexafunctional dipentaerythritol hexaacrylate. Among these,
It is particularly preferable to use a trifunctional or higher functional monomer because a strong film can be formed.

Further, it is necessary to add a photoinitiator in order to efficiently carry out the curing reaction by radiation. Examples include self-cleaving acetophenone-based, benzoin ether-based, hydrogen abstraction-type benzophenone-based, peroxide-based, and thioxanthone-based photoinitiators.
Among these, a highly reactive self-cleaving type initiator is more preferable.

Radiation irradiation is usually accompanied by heat generation. Excessive heat is not preferable because it causes melting and shrinkage of the base film. Therefore, the radiation irradiation device is usually provided with cooling measures such as ventilation. Further, in the production of the thermal transfer recording sheet of the present invention, in order to improve the adhesiveness between each layer formed by the above coating and the substrate, the surface of the substrate is subjected to corona treatment, or a polyester resin. ,
An undercoating treatment with a cellulose resin, a polyvinyl alcohol resin, a urethane resin, a polyvinylidene chloride resin, or the like may be performed.

[0018]

EXAMPLES The present invention will be specifically described below with reference to examples, but the examples do not limit the present invention in any way.

Example 1 (a) Preparation of thermal transfer recording sheet A biaxially stretched polyethylene terephthalate film (thickness 6.0 μm) was used as a substrate, and a sublimable dye (CI Solvent Blue 95) was provided on one surface thereof. An ink consisting of 5 parts, 10 parts of polysulfone resin and 85 parts of chlorobenzene was applied and dried to prepare a sheet having a color material layer having a thickness of about 1 μm. The sheet was wrapped around a 1-inch diameter paper tube and stored at room temperature. This sheet is unrolled, a coating solution having the following composition (A) is applied to the back surface of the color material layer in a wet film thickness of about 12 μm, and after drying,
Using a high-pressure mercury lamp with an energy of 120 W / cm, the distance between the mercury lamp and the film is 115 mm, and the irradiation energy is 12
A sublimation type thermal transfer recording sheet was prepared by treating under the condition of 0 mJ / cm ² to carry out a curing reaction to form a heat resistant slipping layer. This sheet was wrapped around a 1-inch diameter paper tube and stored at room temperature.

Composition (A) Acrylic ester compound Lipoxy SP-1509
(Showa Highpolymer Co., Ltd.) 2.8 parts by weight, hexafunctional monomer KAYARAD DPHA (Nippon Kayaku Co., Ltd.)
1.2 parts by weight, fine particles of silicone resin Tospearl 12
0 (manufactured by Toshiba Silicone Co., Ltd.) 0.4 part by weight, silicone interfacial lubricant L-7500 (manufactured by Nippon Unicar Co., Ltd.)
1.0 part by weight, photoinitiator Darocur1173 (manufactured by Merck) 0.2 part by weight, ethyl acetate 20 parts by weight, isopropanol 5 parts by weight

(B) Preparation of image receptor 10 parts of saturated polyester resin TR-220 (manufactured by Nippon Synthetic Chemical Industry Co., Ltd.), amino-modified silicone KF39
3 (manufactured by Shin-Etsu Chemical Co., Ltd.), 0.5 parts of methyl ethyl ketone, and 15 parts of xylene were applied to a synthetic paper YUPO FPG150 (manufactured by Oji Yuka Synthetic Paper Co., Ltd.) with a wire bar and dried. (Dry film thickness of about 5 μm) Further, heat treatment was performed in an oven at 100 ° C. for 30 minutes to prepare an image receptor.

(C) Transfer recording test The color material layer surface of the sublimation type thermal transfer recording sheet prepared as described above in (a) and the resin coated surface of the image receptor prepared as described above in (b) were tested. Using a partial Grace type line thermal head having a heating resistor density of 8 dots / mm on the heat-resistant slipping layer surface of the recording sheet, 0.4 W / dot of electric power was applied for 10 msec to obtain 8 lines / mm. Transfer recording was performed at a density of 200 mm.

(D) Evaluation items The sublimation type thermal transfer sheet prepared as described above and its transfer recording test were evaluated as follows, and the results are shown in the table.
Summarized in 1. 1. Presence or absence of coating unevenness due to contamination: The color material layer surface was visually observed to see if there was coating unevenness (mainly due to repellency) in the color material layer due to contamination from the heat resistant slipping layer. 2. Whether or not the color material layer was peeled off by the cellophane tape: Whether or not the color material layer was sufficiently adhered to the film was tested using the cellophane tape. 3. Presence or absence of transfer defects: After image transfer, it was visually observed whether the color material layer was not peeled from the base material, or whether an image without transfer unevenness due to coating unevenness was obtained.

Example 2 KAYARAD D used in the heat resistant slipping layer solution of Example 1
Instead of PHA, Lipoxy SP-1509, KAYA
RAD TMPTA (trifunctional, manufactured by Nippon Hiyaku Co., Ltd.),
Lipoxy VR-90 (manufactured by Showa Highpolymer Co., Ltd.) was used, respectively, instead of the photoinitiator Darocur1173, I
RGACURE500 (manufactured by Ciba-Geigy Co., Ltd.) was used, and the same procedure as in Example 1 was performed, and the results are shown in Table 1.
Summarized in.

Example 3 KAYARAD D used in the heat resistant slipping layer solution of Example 1
Instead of PHA and Lipoxy SP-1509, epoxy resin photocurable resin KR-500 (Asahi Denka Kogyo Co., Ltd.)
Manufactured) and no photoinitiator Darocur1173 was used, and the results are shown in Table 1.
Summarized in 1. Comparative Example 1 All the same as in Example 1 except that the color material layer was formed after forming the heat resistant layer instead of forming the heat resistant slipping layer after forming the color material layer. The results are summarized in Table 1.

[0026]

[Table 1]

[0027]

The method for producing a sublimation-type thermal transfer recording sheet of the present invention comprises a production surface due to contamination on the opposite surface of the heat resistant slipping layer,
It has made it possible to solve performance problems and facilitates the production of sublimation type thermal transfer recording sheets with good performance.

Claims (1)

[Claims] 1. A sublimation-type thermal transfer recording sheet having a coloring material layer containing a heat-vaporizable or heat-diffusing dye on one surface and a heat-resistant slipping layer on the other surface. A method for producing a sublimation-type thermal transfer recording sheet, characterized in that a color material layer containing a heat vaporizable or heat diffusible dye is first provided on one surface, and then a heat resistant slipping layer is provided on the other surface.