JPS5921993B2 - Dye printing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a dry dye printing method using electrophotography, and more particularly to a dry dye printing method in which the formed image has excellent abrasion resistance and surface smoothness.

The dry dye printing method using conventional electrophotography is a quick, simple process, inexpensive, and can produce strong prints, so research and development is progressing.

However, in the conventional electrophotographic method, toner adheres to the surface of the printing material, and after printing, the printing method is unsuitable for credit cards, commuter passes, etc. that require surface smoothness and abrasion resistance. , requiring post-processing such as lamination and protective film coating, and as it is desired to simplify the printing process, improvements have been strongly desired.

The object of the present invention is to improve the drawbacks of these conventional electrophotographic methods, and is characterized by the use of a powder ink comprising a heat-transferable dye, a release agent, and a thermoplastic resin.

The present invention will be described in detail below. A dielectric thermoplastic resin, a heat-transferable dye, and a release agent are mixed to create a powder ink having a particle size of 3 to 25 μm, and then an electrostatic latent image is formed as appropriate. A photoconductive photoreceptor made of a metal, a metal oxide, an organic compound, etc. is developed with the powder ink, and then heated to a temperature higher than the softening point or melting point of the thermoplastic resin in the powder ink. The body ink image is fixed onto the photoreceptor.

Next, the chromosome is brought into close contact with the powder ink image surface of the photoreceptor,
The heat-transferable dye in the powder ink is transferred into the chromosome by heating, and then the chromosome and the photoreceptor are separated and cooled, and the transferred powder ink residue is removed from the chromosome. This is a dry dye printing method that forms an appropriate dye image on the chromosome.

Alternatively, a heat-transferable dye, a release agent, and a dielectric thermoplastic resin are mixed to create a powder ink with a particle size of 3 to 25μ, and then an electrostatic latent image is formed on the metal or metal oxide. , or developing a photoreceptor having photoconductivity made of an organic compound or the like with the powder ink to form a powder ink image, and electrostatically or adhesively transferring the powder ink image onto the chromosome, After that, it is heated to dye the heat-transferable dye in the powdered ink onto the chromosome to be dyed, and after cooling, the powder ink residue is removed from the chromosome to be dyed, thereby forming an appropriate dye image on the chromosome to be dyed. This is a dye printing method.

Here, the dielectric thermoplastic resin of the powder ink used in the present invention includes vinyl chloride, vinylidene chloride, vinyl acetate, polystyrene, polyethylene polypropylene, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, Polymers such as diallyl phthalate, ethylene succinate, trimethylene ozalate, butene, butadiene, methyldivinylbenzal, pentene, etc., and their copolymers, or resins such as polyvinyl formal, polyvinyl butyral, ethyl cellulose, acetyl cellulose, acetyl butyl cellulose, etc. and mixtures of these polymers.

Furthermore, as the heat-transferable dye that can be used in the present invention, sublimation or melt-transferable dyes are preferable, and include triphenylmethane dye bases, disperse dyes, smoke dyes, organic solvent-soluble dyes, acid dyes, etc. Generally speaking, the product names are Sumikaron Violet 3BL and Sumikalon Yellow E-FG.

Sumikaron Orange E-01 Sumikalon Violet R
L (manufactured by Sumitomo Chemical Co., Ltd.), Diax Yellow 5R-E1 Dianic Red R-E, Diax Brilliant Red BS-E1 Dianic Navy Blue ER-FS (manufactured by Mitsubishi Chemical Corporation), Osiset Red 2G1 Oraset Red B1 Oraset Blue B1 Oraset Scar Red 2G, Orazol Yellow 3G (manufactured by Ciba), Miketon Polyester Red FB (manufactured by Mitsui Toatsu), Mihara Oil Yellow 5G
, Mihara Oil Blue G1 Mihara Oil Yellow 3G,
Mihara Oil Orange G1 Mihara Oil Orange R1 Mihara Oil Red 5B, Mihara Oil Blue■, Mihara Oil Green QP.

Examples include Mibara Oil Green AX (manufactured by Mihara Kako Co., Ltd.) and Oil Yellow G1 Oil Black FEB (manufactured by Toyo Ink Co., Ltd.).

In addition, as a release agent that can be used in the present invention, resins with weak adhesion to chromosomes, such as silicone-based release agents, are good, and the specific product name is Shin-Etsu Silicon KR215
, KH216 (manufactured by Shin-Etsu Chemical Co., Ltd.), etc.

Photoconductive substances used in the photoreceptor include metals or metal compounds such as selenium, zinc oxide, titanium oxide, and zinc sulfide, and organic compounds such as polyvinylcarbazole, polyacenaphthylene, and acridine.

In addition, the chromosomes referred to in the present invention include synthetic resin sheets or films that have an affinity for heat-transferable dyes, and sheets made by coating the synthetic resin on a substrate such as paper or metal. Examples of the synthetic resin include polyamide, Examples include polyester, polyacrylonitrile, polyolefin, acetyl cellulose, etc.

Next, the present invention will be specifically explained.

First, the powder ink is manufactured by dissolving the resin, heat-transferable dye, and release agent in a solvent such as dioxane or trichlorethylene, mixing them thoroughly, and then using a spray drying method to form a powder with a particle size of 3 to 25 μm. Alternatively, the above mixture is heated, melted and dispersed using two rolls, and pulverized using a pulverizer such as a jet mill to obtain a powder ink having a size of 3 to 25 μm after a classification step.

Although the composition ratio of powder ink varies depending on the purpose, the mixing ratio of dye is generally in the range of 0.5% to 70%,
Preferably it is in the range of 1% to 40%.

Since the release agent itself is often a thermoplastic resin, it can be manufactured in a range of 0.5 to 95%.

If the ratio of dye is increased, it is possible to prevent powder ink from remaining on the chromosome, which is similar to the effect of increasing the ratio of release agent.

When a desired image is projected onto a positively charged selenium plate in a dark place, an electrostatic latent image is formed on the selenium plate.

A powder ink image is obtained by bringing negatively charged powder ink, which has been triboelectrically charged, into contact with this selenium plate.

Next, this powder ink image is electrostatically transferred onto the chromosome to be treated, and by heating, the heat-transferable dye is transferred to the chromosome to form an image, and after cooling, the powder ink residue is removed with a brush or the like. This completes the process.

Similarly, a powder ink image is formed on zinc oxide paper, and the image is obtained by transferring the heat-transferable dye to the chromosome by heating it in close contact with the chromosome, and when it is peeled off after cooling, the thermoplastic resin is attached to the zinc oxide paper. Due to its strong adhesion, images of chromosomes can be obtained with only the dye.

As a result, a dyed print with strong abrasion resistance and almost no discoloration can be obtained.

Hereinafter, the present invention will be explained by examples.

Example 1 35g of polystyrene with a softening temperature of 100°C, 30g of Sumikalon Violet RL, and silicone KR21535y are heated and melted and dispersed using two rolls, and then subjected to a pulverization and classification process using a jet mill to obtain a powder with a particle size of 5 to 20μ. Got the ink.

The ink was negatively charged as a result of frictional charging with iron powder TEF 100-150 mesh (manufactured by Nippon Tetsuko Co., Ltd.).

On the other hand, a selenium photoconductive plate was positively charged by corona discharge in a dark room, an electrostatic latent image was formed by positive pattern exposure, and developed by a magnetic brush method using 2 g of the powder ink and a developer of iron powder 98.9. A positive powder ink image was obtained.

Next, this powder ink image was electrostatically transferred to a 125 μm polyethylene terephthalate (PET) film.
The heat-transferable dye was transferred into the PET film by contacting it with a metal plate heated to .degree. C. for 30 seconds.

After cooling, the powder ink remaining on the PET surface was removed with a brush, and a brightly dyed print was obtained.

Since the powder ink contains a release agent, its adhesive strength with PET is small and removal is easy.

Example 2 A commercially available zinc oxide paper was charged with a negative corona discharge, exposed to a desired negative original, and developed in the same manner using the developer of Example 1 to obtain a positive powder ink image.

Next, the paper is placed in close contact with the chromosome coated with polyester resin, heated to 180℃ and left for 10 seconds to transfer the heat-transferable dye to the chromosome.After cooling, the zinc oxide paper is peeled off and the remaining powder ink is oxidized. It was attached to the zinc paper, and only dye images of the chromosomes were obtained.

By repeating this process, 200 copies could be obtained.

As described in detail above, the dye printing method of the present invention uses powder ink containing a release agent, so when the powder ink image is closely heated and transferred from the photoreceptor to the chromosome, there is no contact with the photoreceptor. Separation work from chromosomes becomes extremely easy.

Therefore, the present invention can be applied to the production of ID cards, bank cards, commuter passes, and other types of cards that require an image in the final step, and the practical effects of the present invention are extremely large.

Claims (1)

[Scope of Claims] 1. Photosensitive material that has photoconductivity by electrophotography using a powder ink consisting of a heat-transferable dye, a release agent, and a dielectric thermoplastic resin (excluding those containing magnetic fine particles). A powder ink image is formed on the body, the chromosome is closely attached to the photoreceptor, heated, the chromosome is dyed with the heat-transferable dye in the powder ink, and after cooling, the powder transferred from the chromosome is A dye printing method characterized by removing body ink residue. 2 Using a powder ink consisting of a heat-transferable dye, a release agent, and a dielectric thermoplastic resin (excluding those containing magnetic fine particles), a powder ink image is created on a photoconductive photoreceptor by electrophotography. The powder ink image is electrostatically or adhesively transferred onto the chromosome to be transferred. After heating, the chromosome is dyed with the heat-transferable dye in the powder ink. After cooling, the powder ink image is transferred onto the chromosome to be transferred by electrostatic or adhesive transfer. A dye printing method characterized by removing ink residue.