JPH04108197A - Method for erasing image and reclaimed paper making - Google Patents

Abstract

PURPOSE:To enable to make reclaimed paper having high whiteness, protect forests and erase the subject images by coating or impregnating a copied images developed with a toner for electronic photography with a specific erasing substance. CONSTITUTION:A copied image developed with an electronic photography toner consisting mainly of a binder component, a colorless to pale colored electron- acceptable coloring organic compound and a developer reacting with the coloring compound to color the coloring organic compound is coated or impregnated with an erasing agent substance selected from electron-donating (or acceptable) materials, alcohols, esters, ketones, ethers and acid amides to erase the image.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for erasing electrophotographic images.

[Prior Art] Recently, there has been an increasing need for the recycling of paper from the viewpoints of forest resource protection and garbage disposal, but electrophotographic toner formulations contain a large amount of binder resin. It was considered difficult to deink the paper and recycle it into highly white recycled paper.

On the other hand, several techniques have been proposed for erasing toner images.

That is, in JP-A-57-65772, electron-accepting coloring a
There is also a description of a reversible temperature-indicating microcapsule containing at least a dye compound and a color developer for the dye. In addition, as a toner for electrophotography using leuco dye,
No. 4376 describes ``a toner containing a colorless to light-colored leuco dye, a developer for the dye, and a color pigment, and forming a two-color copy using a decoloring agent.'' In addition, methods utilizing thermal discoloration have been proposed in JP-A No. 62-14163 and JP-A No. 71277, both of which were insufficient to meet the need for paper recycling.

[Problems to be Solved by the Invention] Under these circumstances, the present invention uses a deinking agent and a color erasing agent simultaneously in the deinking process to improve whiteness even if the toner is not completely disintegrated. The primary objective is to make it possible to recycle recycled paper with a high level of quality, and also to whiten the paper using a simple machine that replaces the decolorizing agent coating roll, making it possible to use the paper repeatedly as is. The second purpose of this paper is to provide an image erasing method and a recycled paper manufacturing method to achieve these goals.

[Means for Solving the Problems] The present invention consists of (1) a binder component, a colorless or light-colored electron-accepting color-forming organic compound, and a color developer that reacts with the compound to form a color; An image is produced by coating or impregnating a copy image developed with an electrophotographic toner with a decolorizing agent selected from electron-donating materials, alcohols, esters, ketones, ethers, and acid amides. An image erasing method characterized by erasing (2) a binder component, a colorless or light-colored electron-donating color-forming organic compound, and a color developer that reacts with the compound to form a color; Erasing the image by coating or impregnating the reproduced image developed with electrophotographic toner with an erasing agent selected from electron-accepting materials, alcohols, esters, ketones, ethers, and acid amides. (3) a binder component, a colorless or light-colored electron-accepting or electron-accepting color-forming organic compound, and a color developer that reacts with the compound to form a color; In a recycled paper manufacturing method in which a copy paper carrying a copy image developed with an electrophotographic toner is disintegrated and recycled, a deinking agent and a color erasing agent for the toner are used in combination in the deinking step. This is a recycled paper manufacturing method characterized by:

Examples of the electron-accepting color-forming organic compound used in the present invention (first invention) include phthaleins and fluoresceins. Specific examples include thymolphthalein, phenolphthalein, 0-cresolphthalein, 1,4-dimethyl-5-hydroquinebenzenesulfophthalein, m-cresolsulfophthalein, a-naphtholphthalein, and 0-cresol. Examples include sulfophthalein, phenol sulfophthalein, fluorescein, sulfofluorescein, tetrabromofluorescein, tetrachlorofluorescein, etc., but are not limited to these, of course.

Examples of color developers for electron-accepting color-forming organic compounds include octylamine, laurylamine, stearylamine, dibutylamine, tripropylamine, dimethylaniline, p-
) Luidine, β-naphthylamine, pyridine, picoline, lutidine, quinoline, piperidine, imidazole, triazine, morpholine and other amines, tetraethylammonium salts and other quaternary ammonium salts, glycine, alanine and other amino acids, potassium hydroxide, Examples include inorganic bases such as sodium hydroxide, but are not limited thereto.

Examples of the electron-donating color-forming organic compounds used in the present invention (second invention) include diarylphthalides, arylphthalides, indolylphthalides, leucoaulamins, rhodamine lactams, spiropyrans, and fluoran kind,
These include phenothiacins, triphenylmethanes, and arylfurans. Examples of these compounds include: crystal violet lactone, malachite green lactone, leuco auramine, rhodamine B lactam, N
-3,3-1-limethylindolinohenzospiropyran, 3-diethylamino-6-methyl-7-chlorofluorane, 3,6-p-toluidino-4,5-dimethylfluorane, 3,3-bis Examples include (l-ethyl-2-methyl-indol-3-yl) phthalide and benzoylleucomethylene blue, but are not limited to these, of course.

Examples of color developers for electron-donating color-forming organic compounds include compounds having a phenolic hydroxyl group and derivatives thereof, compounds having a carboxyl group and derivatives thereof, and the like. Compounds having a phenolic hydroxyl group and their derivatives include monophenols to polyphenols and metal salts thereof, and substituents thereof include alkyl groups, aryl groups, acyl groups, alkoxycarbonyl groups, halokenes, and the like. Examples of these compounds include nonylphenol, styrenate phenols, α-naphthol,
Examples include β-naphthol, hydroquinone, butyl p-oxybenzoate, 4,4-methylene diphenyl, bisphenol A1 bisphenol S1 octyl gallate, phenol resins, etc., and their metal salts include sodium and potassium compounds having the phenolic hydroxyl group. , lithium, calcium, zinc, aluminum, nickel, cobalt, iron, titanium, lead, molybdenum, etc., but are not limited to these. Compounds having a carboxyl group and derivatives thereof include monocarboxylic acids to polycarboxylic acids, substituted derivatives thereof, and metal salts thereof. Examples of these compounds include caproic acid,
Capric acid, lauric acid, myristic acid, valmitic acid, stearic acid, behenic acid, 12-hydroxystearic acid, benzoic acid, protocatechuic acid, gallic acid,
These include phthalic acid, naphthalene dicarboxylic acid, sepatic acid, naphthenic acid, etc., and their metal salts include sodium, potassium, lithium, calcium, zinc,
Aluminum, nickel, cobalt, iron, titanium, lead,
There are metal salts such as molybdenum, but of course the metal salts are not limited to these.

Further, as the binder resin used in the present invention, known resins for toners can be used. For example, monopolymers of styrene and its substituted products such as polystyrene, polyp-styrene, polyvinyltoluene, styrene-p-styrene, etc.
Chlorstyrene copolymer, styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene- Methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer a, styrene-butyl methacrylate copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ether Styrenic copolymers such as copolymers, styrene-vinyl methyl ketone copolymers, styrene-butadiene copolymers, styrene-isoprene copolymers, styrene-maleic acid copolymers, styrene-maleic acid ester copolymers, etc. , polyethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyurethane,
Polyamide, polyester resin, epoxy resin, polyvinyl butyral, polyacrylic acid resin, rosin, modified rosin, terpene resin, phenolic resin, aliphatic or aliphatic hydrocarbon resin, aromatic petroleum resin, chlorinated paraffin, paraffin wax, etc. They can be used alone or in combination.

Furthermore, the toner of the present invention may contain a small amount of a polarity control agent, such as a dye or pigment, a charge control agent, etc., in order to provide more efficient charging, or may contain a small amount of a polarity control agent, such as a dye or pigment, a charge control agent, etc. It is preferable to use a colorless or light-colored polarity control agent. Examples of polarity control agents include metal complexes of monoazo dyes, nitrohumic acid and its salts, salicylic acid, naphthoic acid, dicarboxylic acids and their derivatives such as C01CrSFe, sulfonated copper phthalonanine pigments, nitro groups, and halokenes. Examples include styrene oligomer-1 chlorinated paraffin, melamine resin, etc.

Further, if necessary, a fluidizing agent such as a metal oxide fine powder such as colloidal silica, titanium oxide, or aluminum oxide, an abrasive such as silicon carbide, a lubricant such as a fatty acid metal salt, etc. may be contained.

The toner of the present invention can be used either as a one-component developer or as a two-component developer by mixing it with a carrier. When used as a two-component developer, conventionally known carriers can be used. For example, iron powder, di-sokel powder, ferrite powder, magnetite powder, glass beads, or these are used as a core material with a particle size of about 20 to 200 μm, and fluorine-based resin is coated on the surface.
It can be coated with resin such as silicone resin, styrene resin, or acrylic resin.

Substances that act as decolorizers in both the first and second inventions include n-octyl alcohol, n-nonyl alcohol, n-lauryl alcohol, n-stearyl alcohol, cyclohexanol, benzyl alcohol, and cinnamyl. Alcohol, ethylene glycol, diethine glycol, triethylene glycol, propylene glycol, trimethylolprone, pentaerythritol, sorbitol, mannitol, octyl acetate, butyl propionate, ethyl laurate, benzoin Esters such as ethyl acid, dimethyl phthalate, dioctyl phthalate, dicyclohexyl phthalate, ketones such as benzophenone, methylcyfrotahexanone, acetonylacetone, diacetone alcohol,
Examples include ethers such as diphenyl ether, dioxane, ethylene glycol dibutyl ether, diethylene glycol dibutyl ether, ethylene glycol diethyl ether, and diethylene glycol diethyl ether, and acid amides such as acetamide and propionic acid amide. .

In the first invention, an electron-accepting substance can be used as the decolorizing agent. Examples of electron-accepting substances include compounds having a phenolic hydroxyl group and derivatives thereof, compounds having a carboxyl group and derivatives thereof, and the like. Compounds having a phenolic hydroxyl group and their derivatives include monophenols to polyphenols and metal salts thereof, and substituents thereof include alkyl groups, aryl groups, acyl groups, alkoxycarbonyl groups, halogens, and the like. Examples of these compounds are: nonylphenol 1, styrenated phenols, α-naphthol, β-naphthol, hydroquinone, butyl p-oxybenzoate, 4,4-methylenediphenyl, bisphenol A1 bisphenol S1 octyl gallate. , phenolic resins, etc., and their metal salts include sodium, potassium,
Examples include metal salts such as lithium, calcium, zinc, aluminum, nickel, cobalt, iron, titanium, lead, and molybdenum, but are not limited to these. Compounds having a carboxyl group and derivatives thereof include monocarboxylic acids to polycarboxylic acids, substituted derivatives thereof, and metal salts thereof. Examples of these compounds include acetic acid,
propionic acid, caproic acid, capric acid, lauric acid,
Myristic acid, palmitic acid, stearic acid, hehenic acid, 12-hydroxystearic acid, benzoic acid, protocatechuic acid, gallic acid, phthalic acid, naphthalene dicarboxylic acid, cepatic acid, naphthenic acid, citric acid, etc., and their metals. As the salt, sodium of the carboxylic acid,
Examples include metal salts such as potassium, lithium, calcium, zinc, aluminum, nickel, cobalt, iron, titanium, lead, and molybdenum, and inorganic acids such as hydrochloric acid, sulfuric acid, and nitric acid, but are not limited to these.

Further, in the second invention, an electron-donating substance may be used as the decolorizing agent. Examples of electron-donating substances include octylamine, laurylamine, stearylamine, dibutylamine, tripropylamine, dimethylaniline, p-toluidine, β-naphthylamine, pyridine, picoline, lutidine, quinoline, piperidine, imidazole, triazine, morpholine, etc. amines, quaternary ammonium salts such as tetraethylammonium salt, amino acids such as glycine and alanine, potassium hydroxide,
There are also inorganic bases such as sodium hydroxide.

These color erasing agents can be applied directly with a coating roller or the like to whiten the paper; water-soluble ones can be applied in water, and solvent-soluble ones can be applied in organic solvents such as alcohol, acetone, toluene, etc. It can be diluted in any ratio and applied with a coating roller or the like to whiten paper.

When recycling copy paper having a copy image created using the toner according to the first and second inventions as recycled paper,
By using a conventionally known deinking agent and a color erasing agent for each toner in the deinking process, recycled paper with high whiteness can be recycled even if the toner is completely disintegrated. . Note that since the deinking process is generally performed in water, a water-soluble decoloring agent is used.

Example 1 Styrene/n-butyl methacrylate copolymer (weight average molecular weight 190.000, softening point 125°C) 100 parts by weight Tetrachlorotetrabromoorosein 3 parts by weight 2-aminobenzothiazole 6 parts by weight Bontron E-84 (
Charge control agent = Orient Chemical) 3 parts by weight The above raw materials were mixed in a Henschel mixer, cross-mixed in a three-roll mill, and then cooled. The mixed material was coarsely pulverized, further pulverized with a jet pulverizer, and then with an air classifier to obtain a toner having an average particle size of 10.8 μm.

Add hydrophobic silica fine particles (R9) to 100 parts by weight of the above toner.
72-Nippon Aerosil) was added and mixed using a Henschel mixer. Furthermore, it was mixed with a silicone resin coated carrier to prepare a two-component developer, and a copied image was obtained using FT4460 (manufactured by Ricoh). When the image sample was passed through a roller coated with a 1.5% aqueous solution of citric acid, the image almost disappeared. Furthermore, when the copied image was left for 20 days, most of the image disappeared due to the influence of carbon dioxide in the air or the acidic substance in the paper.

Example 2 Styrene/n-butyl methacrylate copolymer (weight average molecular weight 190.000, softening point 125°C) 100 parts by weight 3.3-
Dimethoxyphenolphthalein 4 parts by weight
-Tolylguanidine 8 parts by weight Hontron E-8
4 (Charge control agent - Orient Chemical) 4 parts by weight A toner was prepared using the above raw materials in the same manner as in Example 1, and when the image sample was passed through a roller coated with a 15% aqueous solution of citric acid, most of the image was erased. did. Further, when the copied image was left for 20 days, the image disappeared completely due to the influence of carbon dioxide in the air or the acidic substance in the paper.

Comparative Example 1 Styrene/n-butyl methacrylate copolymer (weight average molecular weight 190.000, softening point 125°C) 100 parts by weight Carbon black 5 parts by weight Bontron E-84
(Charge control agent - Orient Chemical) 2 parts by weight A toner was prepared by kneading the above raw materials in the same manner as in Example 1, and when the image sample was passed through a roller coated with a 1.5% aqueous solution of citric acid, no image was formed. There was no change. Also,
When the copied image was left for 20 days, there was no change in the image at all.

Example 3 Styrene/n-butyl methacrylate copolymer (weight average molecular weight 190.0 [10 softening point 125°C) 100 parts by weight PSD
-150 (Fluorane-based leuco dye - Nisso Kako) 5 parts by weight Bisphenol A zinc salt 12 parts by weight Bontron E-84
(Charge Control Agent - Orient Chemical) 4 parts by weight A toner was prepared using the above raw materials in the same manner as in Example 1, and a copied image was obtained in the same manner as in Example 1.

1kg image sample with 7% black area and 159. water, NaO
H8g, deinking agent (Tonacrine; manufactured by Nippon Nyukazai Co., Ltd.) 2g
was placed in a dissociator and dissociated for 15 minutes at 30°C. 80 after disintegration
Condensate water squeezed through a mesh wire mesh was added, and flotation was performed for 5 minutes using a floatator. After squeezing this with an 80-mesh wire mesh and adding water, a valve seat was created using a sheet machine. The whiteness of the valve seat was found to be 76.
It was 80 degrees.

Further, when the image sample was passed through a roller coated with an aqueous solution of morpholine O, 89O, the image disappeared completely.

Example 4 Styrene/n-butyl methacrylate copolymer (weight average molecular weight 190.000, softening point 125°C) 100 parts by weight Crystal violet lactone 4 parts by weight2.
3-xylyl acid phosphate 10 parts by weight Bontron E-84 (charge control agent - Orient Chemical) 4 parts by weight A crosstalk toner was prepared using the above raw materials in the same manner as in Example 3 and evaluated. The degree was 78.5%. When the image sample was passed through a roller coated with a 0.8% aqueous solution of morpholine, most of the image disappeared.

Comparative Example 2 Styrene/n-butyl methacrylate copolymer (weight average molecular weight 190.000, softening point 125°C) 100 parts by weight Carbon black 5 parts by weight Bontron E-84 (charge control agent - Orient Chemical) 2 parts by weight A kneaded toner was prepared and evaluated in the same manner as in the example, and the whiteness of the valve seat was found to be 52.5%. Further, when the image sample was passed through a roller coated with a 0.8% aqueous solution of morpholine, there was no change in the image at all.

[Effects] By using the toner of the present invention and simultaneously using a deinking agent and a decoloring agent in the deinking process, it was possible to recycle recycled paper with a high degree of whiteness. It was also possible to whiten the paper using a simple machine equipped with a decoloring agent coating roll and then use the paper repeatedly.

Claims (3)

[Claims] (1) A copy image developed with an electrophotographic toner consisting mainly of a binder component, a colorless or light-colored electron-accepting color-forming organic compound, and a color developer that reacts with the compound to develop color, is An image erasing method characterized in that the image is erased by applying or impregnating it with a donor material, an erasing agent selected from alcohols, esters, ketones, ethers, and acid amides. (2) A copy image developed with an electrophotographic toner consisting mainly of a binder component, a colorless or light-colored electron-donating color-forming organic compound, and a color developer that develops color by reacting with the compound; A method for erasing images, characterized in that the image is erased by applying or impregnating a receptive material with an erasing material selected from alcohols, esters, ketones, ethers, and acid amides. (3) A copy developed with an electrophotographic toner whose main components are a binder component, a colorless or light-colored electron-accepting or electron-accepting color-forming organic compound, and a color developer that develops color by reacting with the compound. A recycled paper manufacturing method in which copy paper carrying an image is disintegrated and recycled, characterized in that in the deinking step, a deinking agent and a decoloring agent for the toner are used together. .