JP2999537B2 - Image forming method - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to an image forming method, and more particularly, to forming an image having excellent gradation and a non-gradation image having excellent density and resolution on the same thermal transfer image-receiving sheet. The present invention relates to an image forming method capable of performing the following.

(Prior art and its problems) Conventionally, various thermal transfer methods are known. Among them, a sublimable dye is used as a recording agent, and this is carried on a base sheet such as paper or a plastic film. age,
Methods for forming various full-color images on a paper plastic film provided with a dye receiving layer have been proposed. In this case, a thermal head of a printer is used as a heating means, and a large number of color dots of three or four colors are transferred to a thermal transfer image receiving sheet by heating for a very short time, and a full-color image of an original is formed by the multicolored 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.

In the transfer method, an image receiving sheet having a dye receiving property,
Since the thermal transfer sheet on which the dye layer is formed is superimposed and printed by heating with a thermal head from the back side, the releasability of both is important after printing, and therefore, a release agent is generally used in the dye receiving layer of the image receiving sheet. Has been added.

However, the above dye images often contain characters and characters.
It is required to record information such as symbols at the same time. Of course, such character information can be simultaneously printed by a sublimation type thermal transfer method. However, character images and the like by this method are generally limited by the resolution of a thermal head. Is unclear and has a problem that the density is inferior to other printing means such as a hot-melt transfer method and a black character image formed by electrophotography.

For this reason, gradation images such as photographs are formed by a sublimation type thermal transfer system, and other character images are printed by another method as described above. Has poor adhesion and is easily peeled off by friction or the like.

Therefore, an object of the present invention is to provide an image forming method capable of forming a dye image having excellent gradation and a non-gradation image having excellent density and resolution on the same thermal transfer image-receiving sheet.

(Means for Solving the Problems) The above object is achieved by the present invention described below. That is,
The present invention forms a gradation image by a sublimation-type thermal transfer method on a thermal transfer image-receiving sheet comprising a substrate sheet and a dye-receiving layer formed on at least one surface of the substrate sheet,
And an image forming method for forming a non-gradation image by a hot-melt transfer method, wherein the dye-receiving layer has a resin and a release agent in the same layer, and the release agent in the layer An image forming method, wherein the content is in the range of 3 to 8 parts by weight per 100 parts by weight of the resin.

(Function) By setting the content of the release agent contained in the dye-receiving layer of the thermal transfer image-receiving sheet to a specific range, a dye image excellent in gradation and a non-tone image excellent in density and resolution can be obtained on the same thermal transfer image-receiving sheet. Can be formed.

Preferred Embodiment Next, the present invention will be described in more detail with reference to preferred embodiments.

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

As the base sheet used in the present invention, synthetic paper (polyolefin, polystyrene, etc.), woodfree paper, art paper, coated paper, cast-coated paper, wallpaper, backing paper, synthetic resin or emulsion impregnated paper, synthetic rubber latex Various plastic films or sheets such as impregnated paper, paper with synthetic resin, paperboard, cellulose fiber paper, polyolefin, polyvinyl chloride, polyethylene terephthalate, polystyrene, polymethacrylate, and polycarbonate can be used. A white opaque film formed by adding a white pigment or a filler to a resin, a foamed foamed sheet, or the like can be used, and is not particularly limited.

Also, a laminate formed by any combination of the above base sheets can be used. Examples of typical laminates include synthetic paper of cellulose fiber paper and synthetic paper or cellulose fiber paper and plastic film or sheet. The thickness of these substrate sheets may be arbitrary, for example, 10 to 300 μm
A moderate thickness is common.

When the substrate sheet as described above has poor adhesion to the dye-receiving layer formed on its surface, it is preferable to apply a primer treatment or a corona discharge treatment to its surface.

The dye receiving layer formed on the surface of the base sheet receives the sublimable dye transferred from the thermal transfer sheet and maintains 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 polyacrylester, polyethylene terephthalate, and poly (ethylene terephthalate). Polyester resins such as butylene 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, polycarbonate and the like, Particularly preferred are vinyl resins and polyester resins.

The dye-receiving layer in the present invention contains a specific amount of a release agent so as to have good releasability from the thermal transfer sheet and good adhesion to the ink layer of the hot-melt transfer sheet.

Preferred release agents include silicone oil, phosphate ester-based surfactants, fluorine-based surfactants, and the like, with silicone oil being 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.

The amount of the above-mentioned release agent to be added is in the range of 3 to 8 parts by weight based on 100 parts by weight of the dye-receiving layer forming resin. When the amount of the release agent is too small, the adhesiveness of the ink layer of the hot-melt transfer sheet is good, but problems such as fusion between the heat transfer sheet and the dye-receiving layer or reduction in printing sensitivity occur. On the other hand, if the amount of the release agent used is too large, the releasability from the thermal transfer sheet is good, but the adhesiveness of the ink layer of the hot-melt transfer sheet is unsatisfactory.

The thermal transfer image-receiving sheet in the present invention is obtained by adding at least one surface of the above-mentioned base sheet to a resin and an additive necessary for a release agent as described above, or dissolving it in a suitable organic solvent, or A dispersion dispersed in water, for example,
It is obtained 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 to form a dye receiving layer.

In forming the dye receiving layer, for the purpose of further improving the sharpness of the transferred image by improving the whiteness of the dye receiving layer,
Pigments and fillers such as titanium oxide, zinc oxide, kaolin clay, calcium carbonate, and finely divided silica can be added. Further, it is preferable to add a fluorescent whitening agent, an antioxidant or an ultraviolet absorber for the purpose of improving the clarity and light resistance of the formed dye image.

The dye receiving layer formed as described above has an arbitrary 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.

The image receiving sheet according to the present invention can be applied to various uses such as a heat transfer recordable sheet, guards, and a sheet for creating a transmission type original by appropriately selecting a base sheet.

Further, 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, and by providing such a cushion layer,
It is possible to transfer and record an image corresponding to image information with little noise during printing with good reproducibility.

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.

Further, a lubricating layer can be provided on the back surface of the base sheet. Examples of the material of the lubricating layer include a methacrylate resin such as methyl methacrylate or a corresponding acrylate resin, and a vinyl resin such as a 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. For example, a detection mark that can be detected by a photoelectric tube detection device can be provided on the back surface of the base sheet by printing or the like.

The thermal transfer sheet used when performing thermal transfer using the thermal transfer image-receiving sheet of the present invention as described above is provided with a dye layer containing a sublimable dye on paper or polyester film. Any of them can be used as it is in the present invention.

As a means for applying thermal energy at the time of thermal transfer, any conventionally known applying means can be used. For example, recording is performed by a recording device such as a thermal printer (for example, Video Printer VY-100, manufactured by Hitachi, Ltd.). By controlling the time, the intended purpose can be sufficiently achieved by applying thermal energy of about 5 to 100 mJ / mm ² .

The image forming method of the present invention is characterized in that a gradation image is formed on the thermal transfer image-receiving sheet by the sublimation thermal transfer method as described above, and a non-gradation image is formed by the heat fusion type transfer method. The image forming method itself by the hot-melt transfer method is known, and any of them can be used in the present invention.

The formation of the gradation image using the dye and the formation of the non-gradation image using the ink layer of the hot-melt transfer sheet are not particularly limited, and either of them may be performed first or simultaneously.

(Examples) 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 As a base sheet, synthetic paper (Yupo-FRG-150, thickness 150)
μm, manufactured by Oji Oil Chemical Co., Ltd.), and applying a coating liquid having the following composition to the other side at a rate of 8.0 g / m ² when dried with a bar coater. After drying for 30 minutes in the same manner, a thermal transfer image-receiving sheet of the present invention was obtained.

Polyester (Byron 600, manufactured by Toyobo Co., Ltd.) 40 parts Vinyl chloride / vinyl acetate copolymer (# 1000A, manufactured by Denki Kagaku Kogyo Co., Ltd.) 60 parts Amino-modified silicone (KF-393, Shin-Etsu Chemical Co., Ltd.) 4 parts Epoxy-modified silicone (KS-343, manufactured by Shin-Etsu Chemical Co., Ltd.) 4 parts Methyl ethyl ketone / toluene (weight ratio 1/1) 400 parts Sublimation type thermal transfer printer (video printer-VY- 100, manufactured by Hitachi, Ltd.), a full-color gradation image was formed, and no problem of peeling between the image receiving sheet and the thermal transfer sheet occurred. Next, when character information was printed on the blank portion of the image receiving sheet with a wax-type thermal transfer printer (AP-860, manufactured by Epson Corporation), the transferability of the printed characters was good and there was no problem with the adhesiveness. When characters were copied and formed in the same margins by an electronic copying machine (Xerox 5039), there was no problem in the adhesiveness of the toner.

Example 2 The following coating liquid was used as the coating liquid in Example 1,
When the formation of the image receiving sheet, the formation of the gradation image, and the formation of the non-gradation image were performed in the same manner as in Example 1, similarly good results were obtained.

Polyester (Byron 600, manufactured by Toyobo Co., Ltd.) 40 parts Vinyl chloride / vinyl acetate copolymer (# 1000A, manufactured by Denki Kagaku Kogyo Co., Ltd.) 60 parts Amino-modified silicone (KF-393, Shin-Etsu Chemical Co., Ltd.) 4 parts Epoxy-modified silicone (KS-343, manufactured by Shin-Etsu Chemical Co., Ltd.) 4 parts Optical brightener (Ubitex OB, manufactured by Ciba Geigy) 0.5 part Methyl ethyl ketone / toluene (1/1 by weight) 400 parts Compare Example 1 The following coating liquid was used as the coating liquid in Example 1,
When the formation of the image receiving sheet, the formation of the gradation image, and the formation of the non-gradation image were performed in the same manner as in Example 1, the adhesiveness of the image with the wax ink and the toner was poor, and the image was easily separated.

Polyester (Byron 600, manufactured by Toyobo Co., Ltd.) 40 parts Vinyl chloride / vinyl acetate copolymer (# 1000A, manufactured by Denki Kagaku Kogyo Co., Ltd.) 60 parts Amino-modified silicone (KF-393, Shin-Etsu Chemical Co., Ltd.) 16 parts Epoxy-modified silicone (KS-343, manufactured by Shin-Etsu Chemical Co., Ltd.) 16 parts Methyl ethyl ketone / toluene (weight ratio 1/1) 400 parts (Effect) According to the present invention as described above, the thermal transfer image-receiving sheet By setting the content of the release agent contained in the dye receiving layer to a specific range, a dye image excellent in gradation and a non-tone image excellent in density and resolution can be formed on the same thermal transfer image-receiving sheet.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-61-237691 (JP, A) JP-A-63-122596 (JP, A) JP-A-61-27290 (JP, A) 127387 (JP, A) JP-A-1-291990 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B41M 5/38-5/40

Claims (2)

(57) [Claims] A thermal transfer image receiving sheet comprising a substrate sheet and a dye receiving layer formed on at least one surface of the substrate sheet, wherein a gradation image is formed by a sublimation type thermal transfer system, and a heat melting type An image forming method for forming a non-gradation image by a transfer method, wherein the dye receiving layer has a resin and a release agent in the same layer, and the release agent content in the layer, An image forming method, wherein the amount is in the range of 3 to 8 parts by weight per 100 parts by weight of the resin. 2. The image forming method according to claim 1, wherein the dye receiving layer contains a fluorescent whitening agent, an antioxidant or an ultraviolet absorber.