JPH0383686A - Thermal transfer image receiving sheet - Google Patents

Abstract

PURPOSE:To provide a sharp image improved in fastness and light resistance by forming a thermal transfer image receiving sheet by providing a dye receiving layer compounded with an oxidation inhibitor represented by the specific general formula to at least the single surface of a base material sheet. CONSTITUTION:Not only an oxidation inhibitor represented by formula I (wherein R1 and R2 are an alkyl group) but also a light stabilizer, an ultraviolet absorber or the like are compounded with a resin such as a polyolefinic resin or a polyester resin and the obtained compound is dissolved or dispersed in an org. solvent to prepare a coating solution. This coating solution is applied to a support such as synthetic paper, fine paper or a plastic film or sheet and dried to form a dye receiving layer. The compounding amount of the oxidation inhibitor represented by the formula I is pref. 0.05 - 10 pts.wt. per 100 pts.wt. of the resin forming the dye receiving layer. A release layer can be also provided to a part or entire surface of the dye receiving layer.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a thermal transfer image-receiving sheet, and more specifically, an object of the present invention is to provide a thermal transfer image-receiving sheet that can form recorded images with excellent fastness, especially light resistance. shall be.

(Prior art and its problems) Conventionally, various thermal transfer methods are known, but among them, a thermal transfer sheet is created by using a sublimable dye as a recording agent and supporting it on a base sheet such as paper or plastic film. Various methods have been proposed for forming full-color images on paper or plastic films provided with dye-receiving layers. In this case, the printer's thermal head is used as the heating means, and a large number of three or four color dots are transferred to the thermal transfer image receiving sheet by extremely short heating, and the multicolor dots create a full-color image of the original. It is intended to reproduce.

The images formed in this way are very clear because the coloring material used is dye, and they have excellent transparency, so the images obtained have excellent intermediate color reproducibility and gradation, and are It is possible to form high-quality images that are similar to images produced by offset printing or gravure printing, and comparable to full-color photographic images.

However, since the resulting images are formed from dyes, they generally have inferior light fastness compared to images using pigments, and there is a problem that the images fade or discolor quickly when exposed to direct sunlight. Although these light fastness problems have been solved to a certain extent by adding ultraviolet absorbers and antioxidants to the dye-receiving layer of thermal transfer image-receiving sheets, it is still not enough, and image preservation is still an important issue. This has become an important issue.

Therefore, an object of the present invention is to provide a thermal transfer image receiving method that provides a clear image with sufficient density in a thermal transfer method using a sublimable dye, and in which the formed image exhibits excellent fastness properties, particularly excellent light fastness. It is to provide sheets.

(Means for solving problems) The above objects are achieved by the present invention as described below.

That is, the present invention comprises a base sheet and a dye-receiving layer formed on at least one surface of the base sheet, and the dye-receiving layer contains an antioxidant represented by the following structural formula (I). This is a thermal transfer image-receiving sheet characterized by being made of a resin.

(However, R4 and R3 in the formula are alkyl groups.)
By incorporating a specific antioxidant into the dye-receiving layer of the thermal transfer image-receiving sheet, it is possible to provide a clear image with sufficient density in the thermal transfer method using sublimation dyes, and the formed image has excellent quality. It is possible to provide a thermal transfer image-receiving sheet that exhibits various fastness properties, particularly excellent light resistance.

(Preferred Embodiments) Next, the present invention will be described in more detail by citing preferred embodiments.

The thermal transfer image-receiving sheet of the present invention consists of a base sheet and a dye-receiving layer provided on at least one surface of the base sheet.

The base sheet used in the present invention includes synthetic paper (polyolefin type, polystyrene type, etc.), high quality paper, art paper,
Coated paper, cast coated paper, wallpaper-backed paper, synthetic resin or emulsion impregnated paper, synthetic rubber latex impregnated paper,
Various plastic films or sheets such as synthetic resin-filled paper, paperboard, cellulose fiber paper, polyolefin, polyvinyl chloride, polyethylene terephthalate, polystyrene, polymethacrylate, polycarbonate, etc. can be used. A white opaque film formed by adding pigments or fillers, a foamed foam sheet, etc. can also be used, but there are no particular limitations.

Further, a laminate made of any combination of the above-mentioned base sheets can also be used. Representative examples of laminates include cellulose fiber paper and synthetic paper, or synthetic paper of cellulose fiber paper and plastic film or sheet. The thickness of these base sheets may be arbitrary, for example, 10 to 300 mm.
The thickness is generally about 100 mm.

When the base sheet as described above has poor adhesion to the dye-receiving layer formed on the surface thereof, it is preferable to subject the surface thereof to a brimer treatment or a corona discharge treatment.

The dye-receiving layer formed on the surface of the base sheet is for receiving the sublimable dye transferred from the thermal transfer sheet and maintaining the formed image.

Examples of the resin for forming the dye-receiving layer include polyolefin resins such as polypropylene, halogenated polymers such as polyvinyl chloride and polyvinylidene chloride, vinyl polymers such as polyvinyl acetate and polyacrylic ester,
Polyester resins such as polyethylene terephthalate and polybutylene terephthalate, polystyrene resins, polyamide resins, copolymer resins of olefins such as ethylene and propylene and other vinyl monomers, ionomers, cellulose resins such as cellulose diacetate, polycarbonates Among them, vinyl resins and polyester resins are particularly preferred.

The thermal transfer image-receiving sheet of the present invention is prepared by dissolving the above-mentioned resin with necessary additives on at least one side of the above-mentioned base sheet in an appropriate organic solvent or dispersing it in an organic solvent or water. A dye-receiving layer is obtained by applying and drying the dispersion by a forming means such as a gravure printing method, a screen printing method, or a reverse roll coating method using a gravure plate.

When forming the above dye-receiving layer, pigments such as titanium oxide, zinc oxide, kaolin clay, calcium carbonate, finely powdered silica, etc. agent can be added.

In the present invention, an antioxidant represented by the following structural formula (I) is added to the dye-receiving layer in order to improve the light resistance of the transferred image formed on the dye-receiving layer.

(However, R1 and R2 in the formula are as defined above.) Examples of antioxidants in which R and R3 in the above formula are C+J□ include Sumilizer TPL-R (manufactured by Sumitomo Chemical Co., Ltd.). An antioxidant in which R3 and R3 in the above formula are CraHst is available under the trade name Sumilizer TPS (manufactured by Sumitomo Chemical), and can be used in the present invention. I can do it. These antioxidants can be used alone or as a mixture.

The amount of the above-mentioned specific antioxidant used is not particularly limited, but
It is preferably used in an amount of 0.05 to 10 parts by weight, preferably 3 to 10 parts by weight, per 100 parts by weight of the resin forming the dye-receiving layer. If the amount used is too small, it will be difficult to obtain the desired effect of the present invention, while if the amount used is too large, it will be uneconomical.

In the present invention, by using a light stabilizer and/or an ultraviolet absorber in addition to the above-mentioned specific antioxidant, even if the total amount used is the same, the weathering resistance is improved more than when the above-mentioned antioxidant is used alone. You can improve your sexuality.

Any known light stabilizer can be used, but particularly effective ones are those represented by the following structure.

Further, as the ultraviolet absorber used in combination, any known ultraviolet absorber can be used, but particularly effective ones are those represented by the following structure.

The amount of the light stabilizer and/or ultraviolet absorber used is not particularly limited, but preferably the resin 1 forming the dye-receiving layer
0.05 to 10 parts by weight, preferably 3 parts by weight
It is used in a proportion of 1 to 10 parts by weight. If the amount used is too small, it will be difficult to obtain the effect of the combined use, while if the amount is too large, it will be uneconomical.

The dye-receiving layer formed as described above may have any thickness, but the thickness for boat fishing is 1 to 50 tLm. Although such a dye-receiving layer is preferably a continuous coating, it may also be formed as a discontinuous coating using a resin emulsion or resin dispersion.

The thermal transfer image-receiving sheet of the present invention can basically be used satisfactorily even with the above configuration, but the dye-receiving layer of the present invention contains a release agent in order to provide good releasability from the thermal transfer sheet. It is preferable to contain.

Preferred mold release agents include silicone oil, phosphate ester surfactants, fluorine surfactants, and silicone oil is preferred. The silicone oil includes epoxy-modified, alkyl-modified, amino-modified,
Modified silicone oils such as carboxyl-modified, alcohol-modified, fluorine-modified, alkylaralkyl polyether-modified, epoxy/polyether-modified, and polyether-modified silicone oils are desirable.

One or more types of mold release agents may be used. The amount of the release agent added is preferably 0.5 to 30 parts by weight per 100 parts by weight of the dye-receiving layer forming resin. If the addition amount does not fall within this range, problems such as fusion between the thermal transfer sheet and the dye-receiving layer or a decrease in printing sensitivity may occur. By adding such a release agent to the dye-receiving layer, the release agent bleeds out onto the surface of the dye-receiving layer to form a release layer.

Further, the image receiving sheet of the present invention can be applied to various uses such as thermal transfer recording sheets capable of thermal transfer recording, cards, transmission type manuscript preparation sheets, etc. by appropriately selecting the base material sheet.

Furthermore, the image-receiving sheet of the present invention can be provided with a cushion layer between the base sheet and the dye-receiving layer, if necessary.
By providing such a cushioning layer, an image corresponding to the image information can be transferred and recorded with good reproducibility with less noise during printing.

Examples of the material constituting the cushion layer include polyurethane resin, acrylic resin, polyethylene resin, butadiene rubber, and epoxy resin. The thickness of the cushion layer is preferably about 2 to 20 μm.

Moreover, a slippery layer can also be provided on the back surface of the base sheet.

Examples of the material for the slipping layer include methacrylate resins such as methyl methacrylate or corresponding acrylate resins, and vinyl resins such as vinyl chloride-vinyl acetate copolymer.

Furthermore, it is also possible to provide a detection mark on the image receiving sheet. The detection mark is extremely convenient when positioning the thermal transfer sheet and the image-receiving sheet, and for example, a detection mark that is detected by a phototube detection device can be provided by printing on the back surface of the base sheet.

The thermal transfer sheet used when performing thermal transfer using the thermal transfer image-receiving sheet of the present invention as described above is one in which a dye layer containing a sublimable dye is provided on paper or polyester film, and conventionally known thermal transfer sheets are All can be used as they are in the present invention.

In addition, any conventionally known means for applying thermal energy during thermal transfer can be used, such as thermal printers (for example,
5 to 100 mJ/mrr by controlling the recording time using a recording device such as -ioo). By applying a certain amount of thermal energy, the intended purpose can be fully achieved.

(Effects) According to the present invention as described above, by including a specific antioxidant in the dye-receiving layer of a thermal transfer image-receiving sheet, clear images with sufficient density can be obtained in a thermal transfer method using sublimable dyes. It is possible to provide a thermal transfer image-receiving sheet that provides a thermal transfer image-receiving sheet, and also shows formed images having excellent fastness properties, particularly excellent light resistance.

(Example) Next, the present invention will be explained in more detail by giving examples and comparative examples. In the text, parts or percentages are based on weight unless otherwise specified.

Example 1 Synthetic paper (Yubo FRG-150, thickness 150 LLm, manufactured by Tamago Yuka Co., Ltd.) was used as a base sheet, and a coating liquid with the following composition was applied to one side of the paper using a bar coater at a dry rate of 10.0 mm.
Apply at a ratio of g/rf, and after temporary drying with a hair dryer,
It was dried in an oven at 100° C. for 30 minutes to obtain a thermal transfer image-receiving sheet of the present invention.

Polyester (Byron 600, manufactured by Toyobo ■) 5.4
Part vinyl chloride/vinyl acetate copolymer (#1000A, manufactured by Denki Kagaku Kogyo ■) 8.0 parts Amino-modified silicone (KF-393, manufactured by Shin-Etsu Chemical ■)
0.25 parts epoxy modified silicone (X-22-343, manufactured by Shin-Etsu Chemical Co., Ltd.)
0.25 parts antioxidant (Su
mtlizer TPL-R1 (manufactured by Sumitomo Chemical) 1.
3 parts methyl ethyl ketone/toluene (weight ratio 1/1)84.
8 parts Example 2 Instead of the antioxidant in Example 1, an antioxidant (S
umilizer TR3, manufactured by Sumitomo Chemical Co., Ltd.) 1.3
A thermal transfer image-receiving sheet of the present invention was obtained in the same manner as in Example 1.

Example 3 In addition to the antioxidant in Example 2, a light stabilizer (
Tinuvln-1130, manufactured by Ciba Geigy) 1.3
A thermal transfer image-receiving sheet of the present invention was obtained in the same manner as in Example 1.

Comparative Example 1 In place of the antioxidant in Example 1, a normal hindered phenolic antioxidant (Irganox-1079) was used.
A thermal transfer image-receiving sheet of a comparative example was obtained in the same manner as in Example 1, except that 1.3 parts of C., Ciba Geigy vA) and 1.3 parts of a benzotriazole light stabilizer (Tinuvin-328, manufactured by Ciba Geigy) were used. .

On the other hand, an ink composition for forming a dye layer having the following composition was prepared,
A dry coating amount of 1.5 μm was applied to a 6 μm thick polyethylene terephthalate film with heat-resistant treatment on the back side. Apply and dry with a wire bar to achieve og/rrf, then add a few drops of silicone oil (X-41 4003A, manufactured by Shin-Etsu Silicone ■) to the back with a dropper, spread it over the entire surface, and apply a back treatment coat. A thermal transfer sheet was obtained.

Disperse dye (Kayaset Blue 14, Nippon Kayaku ■1ri)
4.0 parts Ethyl hydroxycellulose (manufactured by Vercules) 5.0 parts Methyl ethyl ketone/toluene (weight ratio 1/1) 80.
0 parts Dioxane 10.0 parts The above thermal transfer sheet and the above thermal transfer image-receiving sheets of the present invention and comparative examples are superimposed with their respective dye layers and dye-receiving surfaces facing each other, and a thermal head is used to output IW. /dot, pulse width 0.3 to 0.45 m5ec, dot density 3
Printing was performed under the conditions of dots/mm to form a cyan image. A 3.5 hour light fastness test was conducted on this cyan image based on JIS L 0842, and the results shown in Table 1 below were obtained.

Claims (1)

[Scope of Claims] (1) Comprising a base sheet and a dye-receiving layer formed on at least one surface of the base sheet, the dye-receiving layer is an antioxidant represented by the following structural formula (I). A thermal transfer image-receiving sheet characterized by being made of a resin containing an agent. ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) (However, R_1 and R_2 in the formula are alkyl groups) (
2) The content of the antioxidant represented by the structural formula (I) is
The thermal transfer image-receiving sheet according to claim 1, wherein the amount is 0.05 to 10 parts by weight per 100 parts by weight of the resin forming the dye-receiving layer. (3) The thermal transfer image-receiving sheet according to claim 1, wherein the dye-receiving layer further contains a light stabilizer and/or an ultraviolet absorber. (4) The thermal transfer image-receiving sheet according to claim 1, wherein a release agent layer is provided on a part or the entire surface of the dye-receiving layer. (5) The thermal transfer image-receiving sheet according to claim 1, further comprising a cushion layer between the base sheet and the dye-receiving layer.