JPS5830765A - Electrophotographic developer - Google Patents

Abstract

PURPOSE:To obtain a developer capable of decoloring the necessary parts of a color image developed and fixed and easily forming a 2-color image, by adding a leuco dye, its color developer, a pigment for giving color except black or such a dye together with a binder. CONSTITUTION:A colorless or light color leuco dye, such as crystal violet type, its color developing agent, such as phenols or metal benzoate, a heat sensitive coloring sensitizer, auch as aliphatic acid amide, a coloring pigment except for black or such a dye are contained together with a binding resin in a toner. A one-component type toner may be prepared by further adding a magnetic powder. A copy is formed on a copying paper by using this toner for developing. A decoloring soln. containing diethylene glycol and plasticizer, and water or alcohol is coated on the necessary parts of this copy image, thus permitting the coloring dye to be decolored, the colors of the added pigment and the dye to be developed, a 2-color copy having this color and that of the color image to be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a developer for coloring, and more particularly to a developer containing a colorless or light-colored leuco dye, a color developer, and a colorant.

Many patents have been filed regarding the method of forming a λ color image, and among them, for example, Japanese Patent Application Laid-open No.
As disclosed in Patents No. 7, No. 6J, No. 3, and many others, these patents have different wavelength responses. A typical method is to use a photoreceptor in which two types of photoconductor layers are laminated, and to use developers of different colors and opposite polarities.

This method is characterized by obtaining a λ-color image after seven exposures and developments, but since two types of developers are used, the enogy effect of each developer may appear, or the developers may be mixed. However, there are drawbacks such as a decrease in the amount of charge and a decrease in the density of the recorded image.

Furthermore, since two types of developers are used in this case, there is a drawback that the copying apparatus is more complicated than a general-use single-black copying machine.

The present invention improves the above-mentioned drawbacks and provides a developer that can obtain a copy of a black image using an ordinary electrophotographic copying machine and then change the color of the desired portion using diethylene glycol or the like. It is something.

That is, the present invention relates to a dye-coloring heat-sensitive recording material comprising a colorless or light-colored leuco dye and a color developer for the dye, and a developer containing a chromatic color pigment or dye other than black. The agent is loaded into a conventional electrophotographic copying machine and copies are made to obtain black or other colored copies. Next, when you apply diethylene glycol, polyethylene glycol, etc. directly or diluted with water, alcohol, acetate, etc. to the area where you want to create a different color image with a brush or felt-tip pen, the color of the heat-sensitive dye disappears. It changes the color of colored pigments or dyes.

Dye-colored thermal recording has the disadvantage that the color will disappear if it comes into contact with diethylene glycol, polyethylene glycol, etc., or plasticizers contained in plastics. The present invention is a developer for obtaining two-color images by taking advantage of these drawbacks of heat-sensitive recording materials.

Next, the materials used in the present invention will be explained.
As a leuco dye, Crystal Violet Lacto 7
All the dyes used in dye-colored thermal recording paper can be used, such as triphenylmethane dyes, fluoran dyes, auramine dyes, and spiropyran dyes. Color developers include bisphenol A1 paraphenylphenol, phenols such as phenol resin, metal carboxylates such as metal benzoate, and other acidic substances. Further, as a sensitizer for heat-sensitive color development, fatty acid amides such as stearamide and palmitic acid amide, fatty acid metal salts such as zinc stearate, fatty acids, and other waxes can be used.

Suitable examples of pigments and dyes for coloring are shown below, but the present invention is not limited to these. These pigments and dyes can be used alone or in combination of two or more.

Yellow pigment yellow lead, zinc yellow, cadmium yellow, yellow iron oxide, mineral fast yellow, nickel titanium yellow, navy yellow, naphthol yellow S18F-yellow G1
Hansa Yellow IOA, Benzine Eroni G1/Gin Yellow GR, Quinoline Yellow Lake, Permanent Yellow NCG, Tartrazine Lake.

Orange pigment red yellow lead, molybdenum orange, par-r net orange GTR, pyrazolone orange, palkan orange,
Indanthrene Brilliant Orange RK%7 Gin Orange G1 Indanthrene Brilliant Orange GK Red Pigment Pe/Gala, Cadmium Red, Red Lead, Mercury Sulfide Cadmium Permanent Red≠R1 Phosphorus Red, Pyrazolone Red, Watchuncle Calcium Salt, Lake Red D1 Brilliant Carmine 4B, Eosin Lake, Rhodamine Lake B, Iori Zarin Lake, Brilliant Carmine 3B Purple Pigment Manganese Purple, Fast Violet B1 Methyl Violet Lake.

Blue pigments navy blue, cobalt flu, alkali blue lake, Victoria blue sky, phthalocyanine blue, focused x phthalocyanine blue, phthalocyanine blue partially chlorinated,
First Sky Blue, Indance Tremble-Bc.

Green pigment chrome green, chromium oxide, pigment green B1
Malachite Green Lake, Final Yellow Green G White pigment zinc white, titanium oxide, antimony white, zinc sulfide.

Extender pigments Palite powder, barium carbonate, clay, acid clay or activated clay, chestnut, glass powder, white carbon, talc, alumina white.

Basic, acidic 0 dispersion, direct dyes such as nigrosine, methylene blue, loin bengal, kinori/yellow, ultramarine blue, etc.

Other resins commonly used in developers include polystyrene, acrylic resin, epoxy resin, polyamide resin, styrene-acrylic copolymer, polyvinyl chloride,
Synthetic resins and natural resins such as polyvinyl chloride, phenol resin, rosin, shellac, balsam, and asphalt can be mentioned. These resins can be used alone or in combination of two or more.

In addition to the above, the developer has various properties such as improved fluidity,
Various additives can be added for the purpose of imparting polarity and the like.

The developer of the present invention is obtained by mixing and kneading the above materials, pulverizing and classifying them to obtain a toner, and mixing the particles with carrier iron powder etc. to form a two-component developer, which is then used in a copying machine. Alternatively, a magnetic substance may be left in the toner to be used as a -component developer.

The amount of each material to be used is 5% by weight or less, preferably 70 to 0% by weight as a resin, and preferably 7 to 35% by weight of a thermosensitive color forming material consisting of a leuco dye and a color developer. -25% by weight, colored pigments or dyes l-20% by weight, preferably 3-10
The weight percentage of resin, polarizer, fluidity improver, etc. is 10% by weight or less.

In order to erase the colored solid liquid of copies obtained using the developer of the present invention, organic substances with ether bonds such as diethylene glycol, polyethylene glycol, polyoxyethylene alkyl ether, di-λ-ethylhexyl phthalate, etc. Plasticizers for plastics, such as eg, amine compounds such as ethanolamine, can be used as they are, or they can be diluted with water, alcohol, acetone, etc. in any proportion.

Next, the present invention will be specifically explained with reference to Examples.

Example/ The above materials are mixed and melted, and then cooled and solidified.

After crushing and classifying the solidified material, the crimp force is further increased by 0.3% by weight.
In addition,! ~/! A toner having a particle size of about μ was obtained.

This toner was mixed with 10 parts by weight of carrier iron powder to form a developer, and a black image copy was obtained using an electrophotographic copying machine.

When a diethylene glycol ethanol solution was applied to a part of the copy, only that part turned into a bright red image.

Example 2 A black copy was obtained in the same manner as in Example/using the above material. When a diluted diethylene glycol solution was applied to a portion of the copy, only that portion turned yellow.

As described above, by using the developer of the present invention, copies can be made using a conventional electrophotographic copying machine, and the image area can be changed in color through simple processing, such as changing only the stamped area to red. is something that can be done easily.

patent applicant Tomoekawa Paper Mill Co., Ltd.

Claims (1)

[Claims] An electrophotographic developer for forming a two-color image containing at least a colorless to light-colored leuco dye, a color developer for the dye, and a colored pigment or dye other than black.