JP3150720B2 - Method of forming thermal transfer image - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a thermal transfer image , and more particularly to a method for forming a thermal transfer image capable of forming a high-quality image free from defects such as white spots and chips on an arbitrary material to be transferred . Way of formation
About the law .

[0002]

2. Description of the Related Art Various thermal transfer methods are known in the art. Among them, a sublimable dye is used as a recording agent, and this is carried on a base sheet such as paper or plastic film to form a thermal transfer sheet. There have been proposed methods of forming various full-color images on a transfer material such as paper or a plastic film provided with a layer. In this case, a thermal head of a printer is used as a heating means, and a large number of three or four color dots are transferred to a transfer material by heating for a very short time, and a full-color image of an original is formed by the multicolor dots. Is to reproduce. The image formed in this way is very clear because the coloring material used is a dye, and is excellent in transparency, so that the obtained image is excellent in the reproducibility and gradation of intermediate colors. It is possible to form a high-quality image which is similar to an image by offset printing or gravure printing, and is comparable to a full-color photographic image.

[0003]

[Problems to be solved by the invention]
The transfer material on which an image can be formed by the above method is limited to a dye-dyeable plastic sheet or a paper provided with a dye-receiving layer in advance, and cannot directly form an image on ordinary plain paper. There's a problem. Of course, it is possible to form an image even on ordinary plain paper if the receiving layer is formed on the surface thereof, but this is generally costly. For example, postcards, memos, stationery, reports It is difficult to apply to a general ready-made transfer receiving material such as paper. As a method for solving such problems, when an image is to be formed on a ready-made transfer receiving material such as plain paper, a method for easily forming a dye receiving layer only on a necessary portion thereof is a receiving layer transfer sheet. Is known (for example, see Japanese Patent Application Laid-Open No. 62-264994).

However, in the case of using the receiving layer transfer sheet as described above, there is little problem in the case of processed paper having a smooth surface, but in the case of plain paper, postcards, and other papers having a coarse surface, fibers are present on the surface. Because the exposed surface lacks smoothness, the transfer of the receiving layer is not performed uniformly, so that an image formed on the receiving layer has white spots or chips, and a high-quality image cannot be obtained. There's a problem. As a method for solving these problems, it has been proposed that bubbles are included in a part of the transfer layer of the receiving layer transfer sheet to give the transfer receiving layer an excellent cushioning property. When an image is formed with a thermal head after the transfer, bubbles in the transfer layer are re-expanded due to the heat of the thermal head, causing a problem that a defect occurs in the receiving layer and adversely affects the image. Accordingly, the present invention aim to solve the above problems, the surface of the thermal transfer image image makes it possible to form a high-quality and high-density image free from white spots and also lack rough paper or the like not smooth
It is to provide a forming method .

[0005]

The above object is achieved by the present invention described below. That is, the present invention relates to a receptor layer transfer sheet.
Heat the receptor layer on paper with exposed fibers.
Transferring and sublimation transfer on the thermally transferred receiving layer.
Forming a dye image by a method
In the method for forming an image, it said receptive layer transfer sheet, a receptive layer transfer sheet formed by providing a transfer resin layer on one surface of the substrate sheet, the transfer resin layer is a dye-receiving layer and the bubble-containing layer wherein the door, barrier layer between the bubble-containing layer and the dye receiving layer is formed, the bubble-containing layer is a method for forming a thermal transfer image, characterized in that also serves as an adhesive layer.

[0006]

[Function] Using a transfer sheet for receiving layer, fibers are exposed on the surface
Thermally transferring the receiving layer to the paper being processed; and
A dye image on the receiving layer by sublimation transfer
And forming a thermal transfer image.
The transfer resin layer of the transfer sheet is divided into a receiving layer and a bubble-containing layer, a barrier layer is provided between them, and the bubble-containing layer also serves as an adhesive layer. When formed, even if the bubbles are re-expanded by the heat of the thermal head, no defect occurs in the receiving layer, and therefore, high quality and high density without white spots or chipping even on rough paper having an uneven surface. and forming child images
Can.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will now be described in more detail with reference to preferred embodiments. One example of the receiving layer transfer sheet used in the present invention is, as schematically shown in FIG. 1, a receiving layer transfer sheet having a transferable resin layer provided on one surface of a base sheet 1. The layer includes a dye-receiving layer 2 and a bubble-containing layer 3, a barrier layer 4 is formed between the dye-receiving layer 2 and the bubble-containing layer 3, and the bubble-containing layer also serves as an adhesive layer. Features. In addition, 6 in a figure is a heat-resistant lubricating layer. As the base sheet used in the image receiving layer transfer sheet used in the present invention , the same base sheet as that used in the conventional thermal transfer sheet can be used as it is, and other materials can also be used. Not restricted. Specific examples of preferred substrate sheets include, for example, thin paper such as glassine paper, condenser paper, and paraffin paper, polyester, polypropylene, cellophane, polycarbonate, cellulose acetate, polyethylene, polyvinyl chloride, polystyrene, nylon, polyimide, and polyvinylidene chloride. And a plastic sheet such as an ionomer or a base sheet obtained by combining these with the paper. The thickness of the base sheet can be appropriately changed depending on the material so that the strength and heat resistance are appropriate, but the thickness is preferably 3 to 100 μm.
m.

Prior to the formation of the receiving layer, it is preferable to form a release layer on the surface of the substrate sheet. Such a release layer is formed from a release agent such as a water-soluble resin, a hydrophilic resin, a wax, a silicone wax, a silicone resin, a fluorine resin, and an acrylic resin. The formation method may be the same as the formation method of the receptor layer described below, and the thickness of about 0.1 to 5 μm is sufficient. If a matte receiving layer is desired after transfer, the release layer may be made into a matte surface by incorporating various particles in the release layer or by using a base sheet having a matte surface on the release layer side surface. Of course, if the above-mentioned substrate sheet has an appropriate releasability, it is not necessary to form a release layer.

The dye receiving layer formed on the surface of the base sheet receives the sublimable dye transferred from the thermal transfer sheet after transferring the receiving layer to an arbitrary material to be transferred, and maintains the formed image. It is for. Examples of the resin for forming the dye receiving layer include polyolefin resins such as polypropylene, vinyl chloride-vinyl acetate copolymer, polyvinyl chloride, halogenated polymers such as polyvinylidene chloride, polyvinyl acetate, and polyacryl ester. Such as vinyl polymers, polyethylene terephthalate, polyester resins such as polybutylene terephthalate, polystyrene resins, polyamide resins, copolymer resins of olefins such as ethylene and propylene and other vinyl monomers,
Examples thereof include cellulose resins such as ionomers and cellulose diacetates, and polycarbonates. Particularly preferred are vinyl resins and polyester resins.

Preferred release agents to be used by mixing with the above resin include silicone oil, phosphate ester surfactants, fluorine surfactants, etc., but silicone oil is preferred. As the silicone oil, a modified silicone oil such as epoxy-modified, alkyl-modified, amino-modified, carboxyl-modified, alcohol-modified, fluorine-modified, alkylaralkyl-polyether-modified, epoxy / polyether-modified, or polyether-modified is preferred. One or more release agents are used. or,
The amount of the release agent to be added is preferably 0.5 to 30 parts by weight based on 100 parts by weight of the resin for forming the dye receiving layer. If the addition amount is not satisfied, problems such as fusion of the thermal transfer sheet and the dye receiving layer or reduction in printing sensitivity may occur. By adding such a releasing agent to the dye receiving layer, the releasing agent bleeds out on the surface of the receiving layer after transfer to form a releasing layer.

The receiving layer is formed by dissolving the above-mentioned resin to which one of the above-mentioned resins and necessary additives such as a releasing agent are added on one side of the above-mentioned base material sheet in a suitable organic solvent, or It is formed by applying and drying a dispersion dispersed in water by a forming means such as a gravure printing method, a screen printing method, and a reverse roll coating method using a gravure plate. In forming the dye receiving layer,
Kaolin clay, for the purpose of improving the foil cut of the receiving layer,
Fillers such as calcium carbonate and finely divided silica can be added. The dye-receiving layer formed as described above may have any thickness, but generally has a thickness of 1 to 50 μm.
Further, such a dye receiving layer is preferably a continuous coating, but may be formed as a discontinuous coating using a resin emulsion or a resin dispersion.

Further, a barrier layer 4 is formed on the surface of the receiving layer. Such a barrier layer is, for example, coated with a solution of a resin having good coatability such as polyamide resin, acrylic resin, vinyl chloride resin, ethylene-vinyl acetate copolymer resin, vinyl chloride-vinyl acetate copolymer resin, polyester resin and the like. By drying, preferably 0.1
It is formed to a thickness of about 10 μm.

The bubble-containing layer formed on the barrier layer may be a binder such as polyurethane resin, acrylic resin, polyethylene resin, butadiene rubber,
It is formed by applying and drying a coating liquid containing a thermoplastic resin such as an epoxy resin containing air bubbles. There are a method for containing bubbles, a method for containing bubbles themselves, and a method for containing a foaming agent and foaming the foaming agent after forming a layer. As the foaming agent to be used, a decomposable foaming agent such as dinitropentamethylenetetramine, diazoaminobenzene, azobisisobutyronitrile, azodicarbonamide which decomposes at a high temperature to generate a gas such as oxygen, carbon dioxide, and nitrogen. Any known foaming agent such as microballoons obtained by microencapsulating a low-boiling liquid such as butane and pentane with a resin such as polyvinylidene chloride and polyacrylonitrile can be used. Microballoons and the like coated with a white pigment can also be used effectively. The amount of the foaming agent or foam used is such that the foaming ratio of the layer containing the bubbles is 1.5 to 1.5.
What is necessary is just to use it in the ratio which becomes the range of about 20 times. Particularly preferred foaming agents are the microballoons capable of foaming at a relatively low temperature, the microballoons coated with the foam and the white pigment, for example, various grades available from Matsumoto Yushi Seiyaku, Any of them can be used in the present invention. The thickness of these bubble-containing layers is 2 to
About 10 μm is preferable.

In the present invention, in order to further improve the transferability of the above-mentioned transferable resin layer, the above-mentioned bubble-containing layer also serves as an adhesive layer. These foam-containing adhesive layers are coated and dried with a solution of a resin having good adhesiveness when heated, such as a polyamide resin, an acrylic resin, a vinyl chloride resin, a vinyl chloride-vinyl acetate copolymer resin, and a polyester resin. Thereby, it is preferably formed to a thickness of about 0.5 to 10 μm. Further, in the present invention, by providing a filler, a white pigment, a fluorescent whitening agent and the like in at least one of the above layers, a receiving layer having excellent whiteness regardless of the ground color of the material to be transferred is provided. Can be done.

Using the receiving layer transfer sheet as described above,
The transfer material to transfer the transfer layer comprising a receiving layer, card,
Postcard, passport, letter paper, report paper, notebook, catalog, etc., rough the surface of the eye, especially plain paper, which is a rough paper, and the like.
The transfer layer can be transferred by any heating method that can be heated to a temperature at which the receiving layer or the adhesive layer is activated, such as a general printer having a thermal head for thermal transfer, a hot stamper for a transfer foil, and a heat roll. Pressure means may be used.

[0016]

Next, the present invention will be described more specifically with reference to examples and comparative examples. In the following description, parts and% are based on weight unless otherwise specified. Example 1 A coating solution for a receiving layer having the following composition was applied to a surface of a 25 μm-thick polyester film (trade name “Lumirror”, manufactured by Toray Industries Co., Ltd.) at a rate of 5.0 g / m ² when dried with a bar coater. Then, after temporary drying with a drier, drying in an oven at 100 ° C. for 30 minutes to form a dye receiving layer, and the following coating liquid for a barrier layer is dried at a rate of 3 g / m ² on the receiving layer. On the barrier layer, the following coating solution for a bubble-containing layer and an adhesive layer was similarly applied at a rate of ² g / m ² at the time of drying and dried to form a bubble-containing layer and an adhesive layer.
For 2 minutes to obtain a receiving layer transfer sheet. Coating liquid composition for receptor layer ; Vinyl chloride / vinyl acetate copolymer (VYHD, manufactured by Union Carbide) 100 parts Epoxy-modified silicone (KF-393, manufactured by Shin-Etsu Chemical Co., Ltd.) 1 part Amino-modified silicone (KS-343, Shin-Etsu Chemical industry) 1 part Methyl ethyl ketone / toluene (weight ratio 1/1) 500 parts Coating composition for barrier ; polymethyl methacrylate resin (BR-106, manufactured by Mitsubishi Rayon) 100 parts Methyl ethyl ketone / toluene (weight ratio 1/1) 500 parts Coating solution composition for adhesive layer ; polymethyl methacrylate resin (BR-106, manufactured by Mitsubishi Rayon) 100 parts Blowing agent (F-300, manufactured by Matsumoto Yushi Pharmaceutical) 10 parts Titanium oxide (TCA-888, Tochem Products) 100 parts methyl ethyl ketone / toluene (weight ratio 1/1) 500 parts

Example 2 A receiving layer transfer sheet was formed in the same manner as in Example 1 except that 15 parts of microcapsules (F-30D, manufactured by Matsumoto Yushi Seiyaku Co., Ltd.) were used instead of the foaming agent in Example 1. . Example 3 Instead of the foaming agent in Example 1, titanium-coated microcapsules (F-30D / Matsumoto Yushi Pharmaceutical Co., Ltd.)
A receiving layer transfer sheet was formed in the same manner as in Example 1 except that 15 parts of TiO ₂ ) were blended. Comparative Example 1 A receiving layer transfer sheet of a comparative example was formed in the same manner as in Example 1 except that no foaming agent was used.

On the other hand, an ink for a dye layer having the following composition was prepared, and applied to a 6 μm-thick polyethylene terephthalate film having a heat-resistant back surface, with a dry coating amount of 1.0 g / m ^2.
Apply and dry with a wire bar so that it becomes like this. Further, drop a few drops of silicone oil (X-41 / 4003A, made by Shin-Etsu Silicone) on the back with a dropper, spread it over the entire surface and coat it on the back to obtain a thermal transfer sheet. Was. Ink composition for dye layer : Disperse dye (Kayaset Blue 714, manufactured by Nippon Kayaku) 4.0 parts Ethyl hydroxycellulose (manufactured by Hercules) 5.0 parts Methyl ethyl ketone / toluene (weight ratio (1/1) 80.0 parts) 10.0 parts of dioxane The receiving layer transfer sheet and the plain paper were superimposed on each other, and the receiving layer was transferred by using a hot roll. Printing was carried out under the conditions of an output of 1 W / dot, a pulse width of 0.3 to 0.45 msec, and a dot density of 3 dots / mm to form a cyan image.The quality of each color image obtained above is shown in Table 1. .

[0019]

[Table 1]

[0020]

According to the present invention as described above, the present invention can be used.
When the transfer resin layer of the receiving layer transfer sheet to be used is divided into a receiving layer and a bubble-containing layer also serving as an adhesive layer, and a barrier layer is provided therebetween, so that an image is formed by a thermal head after transferring the receiving layer. Even if the bubbles are re-expanded by the heat of the thermal head, no defects are generated in the receiving layer, and therefore, high quality and high density images without white spots or chips are formed even on rough paper having an uneven surface. Ru child and is able to <br/>.

[Brief description of the drawings]

FIG. 1 is a diagram schematically illustrating a cross section of a receiving layer transfer sheet used in the present invention.

[Explanation of symbols]

 1: base material sheet 2: receiving layer 3: bubble-containing layer 4: barrier layer 5: adhesive layer 6: heat-resistant lubricating layer

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-63-231984 (JP, A) JP-A-64-27996 (JP, A) JP-A-63-89390 (JP, A) JP-A-2- 179793 (JP, A) JP-A-3-153390 (JP, A) JP-A-3-266691 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B41M 5 / 38-5 / 40

Claims (3)

(57) [Claims] (1) using a receptor layer transfer sheet, the fibers are coated
Thermally transferring the receptor layer to paper exposed to the
A dye image is formed on the transferred receiving layer by sublimation transfer.
Forming a thermal transfer image having a step of forming
Said receptor layer transfer sheet comprises a receiving layer transfer sheet formed by providing a transfer resin layer on one surface of the substrate sheet, the transfer resin layer and a dye-receiving layer and the bubble-containing layer, said bubble A barrier layer is formed between the containing layer and the dye receiving layer,
A method for forming a thermal transfer image, wherein the bubble-containing layer also functions as an adhesive layer. 2. The transferable resin layer contains a white pigment.
3. The method for forming a thermal transfer image according to 1 . 3. The method according to claim 2 , wherein the resin layer contains a white pigment.