JPH07134524A - Method for reproducing image receiving sheet - Google Patents

Abstract

PURPOSE:To quickly and efficiently remove toner without using solvent and to reproduce an image receiving sheet by attaching or absorbing a toner image recorded on the image receiving sheet. CONSTITUTION:A device is constituted of the image receiving sheet 101, a toner-absorbed image 102, a lower roller 103 and a roller 104 provided with absorptivity. It is also good that a roller provided with a heated metallic surface is used or an oil absorbing organic material or a metallic material by considering the improvement of the absorptivity is used for the roller 104. Besides, it is also good that the rollers 103 and 104 are formed of a different material or the entirely identical material is used as the rollers 103 and 104. Then, the image receiving material on which the toner image is formed is passed between the heated and pressured rollers 103 and 104 so that the toner image is brought into contact with the roller 104 and the toner is removed from the image receiving material while being melted. At this time, a means for preheating, before processing executed by the roller 104, can be also used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of reproducing an image receiving sheet by removing a toner image recorded with a toner on a paper or a film.

[0002]

2. Description of the Related Art A recording paper used in a so-called copying machine or printing is adapted to carry a visible image by adhering ink or toner on the surface thereof so as to function as a recording medium. By the way, such recording paper is made from pulp as a raw material, and in recent years, it has been proposed to reuse it from the viewpoint of resource conservation.

As a method of deinking the above-mentioned copy image,
For example, as disclosed in Japanese Patent Application Laid-Open No. 4-300395, a method of dissolving and removing the toner of a copy image with a solvent or the like, or as disclosed in Japanese Patent Application Laid-Open No. 5-100472, the colorant of the toner is photoreacted A method of erasing by using is known. However, the above-mentioned image erasing method is
They are not satisfied with the working environment because they need solvents,
The colorant of the copy image deteriorates with time in daylight, and the cyanine dye is used to generate a chemically active species by irradiating infrared rays. That only a thing can be obtained, that a slightly colored component remains even after erasing, and that the safety of the chemical species generated in the erasing process is unknown because the erasing reaction is used. There was something unsatisfactory that I said.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems. That is, an object of the present invention is to provide a method for regenerating an image receiving sheet by removing toner quickly and efficiently without using a solvent.

[0005]

According to the present invention, a toner image recorded on an image-receiving sheet such as paper, film or the like is brought into contact with a toner-adhesive member or an absorbing member in a state where the toner image is heated and melted. The present invention relates to a technique for removing toner from an image receiving sheet, and an object of the present invention is to
This is achieved by a method for reproducing an image receiving sheet, which comprises removing the toner from the surface of the image receiving sheet by adhering or absorbing the toner image recorded on the image receiving sheet.

Generally, when the toner is heated to a temperature above its softening point, the binder resin used is softened and fluidized. The melted toner has adhesiveness to various materials. According to the present invention, a member capable of selectively adhering toner to an image receiving sheet used is brought into contact with a copy image in a heat-melted state to efficiently adsorb the toner image and reproduce the image receiving sheet. It is a thing.

As the member to be brought into contact with the image used for the above, it is preferable to use a member having a surface energy as high as possible or, particularly, an selectively oil-absorbing member. Specific examples of such a material include metal rollers such as aluminum, iron, and stainless steel. In addition, various rubber materials, specifically methyl rubber, butadiene rubber, styrene-butadiene rubber, nitrile-butadiene rubber, neoprene rubber, polyisobutylene rubber, polysulfide rubber, acrylic rubber, polyurethane rubber, chlorosulfonated polyethylene rubber Etc. can be mentioned. When a rubber material is used among the above materials, the usage pattern may be such that a metal roller is covered with a rubber material, or a sheet is formed from the rubber material and brought into contact with the toner image on the sheet. You can also Further, the above-mentioned member is preferably processed so as to have pores on its surface or inside. Further, the above-mentioned metal roller may be formed of a magnetic material to give adaptability to magnetic toner.

There are various modes for carrying out the deinking process of the present invention. Usually, an image receiving sheet having a copied image copied by a copying machine is heated or pressed by a roller or a sheet. This is due to processing. In this step, the temperature is important for removing the toner image, and the step is performed at a temperature of 30 ° C. or higher, preferably 50 ° C. or higher than the glass transition point (Tg) of the toner binder resin used. It is the preferred embodiment.

The image-receiving sheet used in the present invention includes:
Commonly used copy papers such as high-quality papers, coated papers, art papers, synthetic papers, laminating papers, polymer sheets such as PET films, and the like can be mentioned. Further, in order to effectively remove the heat-fixing toner by using the process of the present invention, an image-receiving sheet is used which does not allow the toner whose surface layer is melted to penetrate into the fiber, surface coat, or image-receiving material. Preferably. Specific examples of such an image receiving material include surface roughness Ra.
Coated paper having a diameter of 3.0 μm, preferably less than 2.5 μm,
Mention may be made of art paper, synthetic paper, polymeric films, and / or surface-coated polymeric films.

The process of the present invention can also be used for pressure fixing toners. When the process of the present invention is applied to the pressure-fixing toner, the heating temperature may be relatively low, as long as the contacting member can sufficiently absorb the toner component.

The toner that can be removed by the present invention is
Mention may be made of those which are fixed by heat and / or pressure. Specific examples of the binder resin used in such a toner include a heat fixing toner typified by, for example, a styrene-acrylic copolymer, a pressure fixing microcapsule toner, and a toner produced by granulation polymerization. Can be mentioned.

Specific examples of the binder resin used in the above-mentioned toner include polymer compounds such as polystyrene, poly-p-chlorostyrene, and polyvinyltoluene such as polyvinyltoluene, and styrene-p.
-Chlorostyrene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-acrylic acid ester copolymer, styrene-methacrylic acid ester copolymer, styrene-α-chloromethylmethacrylate copolymer Polymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer, polyvinyl chloride, phenol resin, modified Phenolic resin, malein resin, acrylic resin, methacrylic resin,
Polyvinyl acetate, silicone resin, aliphatic polyhydric alcohol, aliphatic dicarboxylic acid, aromatic dicarboxylic acid, aromatic dialcohols, polyester resin having a monomer selected from diphenols as a structural unit, polyurethane resin, Examples thereof include polyamide resin, polyvinyl butyral, terpene resin, coumarone indene resin, petroleum resin, crosslinked styrene resin and crosslinked polyester resin.

Of the above-mentioned binder resins, the polymerizable monomer used in the styrene-acrylic copolymer is, for example, acrylic acid, methyl acrylate, ethyl acrylate, or acrylic acid. Ethylenic double such as butyl acrylate, dodecyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, octyl methacrylate, acrylonitrile, methacrylonitrile, acrylamide Acrylic esters having a bond; Maleic acid, half-esters of maleic acid such as butyl maleate, and diesters; vinyl acetate, vinyl chloride, vinyl methyl ether,
Examples thereof include vinyl esters such as vinyl ethyl ether, vinyl propyl ether and vinyl butyl ether; and vinyl ketones such as vinyl methyl ketone, vinyl ethyl ketone and vinyl hexyl ketone.

Examples of the above-mentioned cross-linking agent include compounds mainly having two or more unsaturated bonds, specifically, aromatic divinyl compounds such as divinylbenzene and divinylnaphthalene; ethylene glycol diacrylate and ethylene glycol. Carboxylic acid ester having two unsaturated bonds such as dimethacrylate; divinylaniline, divinylether, divinylsulfide, divinylsulfone and other divinyl compounds, and compounds having three or more unsaturated bonds are used alone or in combination. be able to. The above-mentioned cross-linking agent is preferably used in an amount of 0.01 to 10% by weight, preferably 0.05 to 5% by weight, based on the binder resin.

A binder resin for pressure fixing toner can be used for the pressure fixing toner when the pressure fixing method is used, and specifically, for example, polyethylene, polypropylene, polymethylene, polyurethane elastomer, ethylene. -Ethyl acrylate copolymer, ethylene-vinyl acetate copolymer, ionomer resin, styrene-butadiene copolymer, styrene-isoprene copolymer, linear saturated polyester, paraffin and other waxes can be mentioned.

In order to fully exert the effects of the present invention, it is preferable to use a polymer having a glass transition point (Tg) of 45 ° C. to 110 ° C. among the above resins used for toner. This is suitable for favorably setting the black condition. Furthermore, a gel component for improving the melt viscosity characteristic or for imparting offset resistance may be added or mixed in the above-mentioned toner.

In the toner used in the present invention, a charge control agent may be blended with the toner for use. By adding the charge control agent, the charge amount can be optimized according to the developing system. Examples of the positive charge control agent include nigrosine and fatty acid metal salt derivatives; quaternary ammonium salts such as tributylbenzylammonium-1-hydroxy-4naphthosulfonate and tetrabutylammonium tetrafluoroborate; dibutyltin oxide.
Diorgano tin oxide such as dioctyl tin oxide and dicyclohexyl tin oxide, dibutyl tin oxide, dioctyl tin borate and dicyclohexyl tin borate may be used alone or in combination of two or more kinds. Among the charge control agents described above, the charge control agents such as nigrosine type and quaternary ammonium salts are particularly preferable.

In the present invention, a negative charge control agent can also be used. Specifically, for example, organometallic complexes and chelate compounds are effective, and aluminum acetylacetonate, iron (II) acetylacetonate, 3 Mention may be made of chromium 5,5-di-tert-butylsalicylate. Particularly, metal complexes of acetylacetone (including monoalkyl-substituted products and dialkyl-substituted products), salicylic acid-based metal complexes (including monoalkyl-substituted products and dialkyl-substituted products) or salts thereof are preferable, and salicylic acid-based metal salts are particularly preferable. Is. When the above charge control agent is added to the toner, 0.1 to 20% by weight based on the binder resin,
It is preferable to use 0.2 to 10% by weight. Particularly when used for color image formation, it is preferable to use a colorless or light-colored charge control agent.

As the colorant that can be added to the toner used in the present invention, conventionally known dyes and pigments can be used, and specifically, for example, carbon black, magnetite, ferrite, phthalocyanine blue. , Peacock blue, permanent red, lake red, rhodamine lake, Hansa yellow, permanent yellow, benzidine yellow and the like can be used. The amount added at that time is 0.1 to 20% by weight, preferably 0.5 to 20% by weight, based on the binder resin.
Further, considering the suitable transparency of the OHP film of the toner image, it is preferably used in the range of 12% by weight or less, and most preferably 0.5 to 9% by weight.
Among the toners using the above-mentioned colorant, the present invention is particularly effectively used for a magnetic toner in which a magnetic material is used as the colorant.

The toner used in the present invention may contain fine powder such as silica, alumina, titanium oxide, polytetrafluoroethylene, polyvinylidene fluoride, polymethylmethacrylate, polystyrene and silicone.

1 and 2 are schematic diagrams of the image removal process used in the present invention. In FIG. 1, 1
Reference numeral 01 is an image receiving sheet, 102 is a toner image, 103 is a lower roller, and 104 is an adsorbing roller. The adsorptive roller may have a heated metal surface, and in particular, in consideration of improvement of adsorptivity,
An oil absorbing organic material or a metal material may be used. Further, the rollers 103 and 104 may be formed of different materials, or the same rollers may be used. The image-receiving material having a toner image is one in which the toner image is passed between the heated and pressed rollers so that the toner image is in contact with the absorptive roller to melt the toner and remove it from the image-receiving material. At this time, the adsorptive roller 1
Means such as preheating prior to treatment with 04 can also be used.

FIG. 2 describes the process of removing toner from the image receiving material using an adsorbent sheet instead of an adsorbent roller. 201 is an image receiving sheet, 20
2 is a toner image, 203 is a lower roller, 204 is an absorptive sheet (adsorptive belt), 205 is an upper roller, 2
06 is a guide roller. As the adsorptive sheet, the sheet-forming material itself may be an oil-absorptive material, or a material which is not oil-absorptive by itself is provided with process compatibility by modifying the surface or the inside. It may be. Examples of such a modification method include surface coating, surface corona treatment, pore formation, and foam molding means, but are not necessarily limited to the methods described above.

The process of the present invention can be carried out by repeating the process described in FIGS. 1 and 2 a plurality of times for the same image receiving material depending on the density of the image on the remaining image receiving material. Furthermore, the methods described in FIGS. 1 and 2 can be used in combination as appropriate. The toner adsorbed on the adsorptive roller or the adsorptive sheet is removed and collected by a cleaning mechanism (not shown).

Next, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples. "Parts" means "parts by weight".

[0025]

Example 1 Styrene-butyl acrylate-divinylbenzene copolymer 100 parts (copolymerization weight ratio 70/30/2, weight average molecular weight (Mw) 50,000, Tg 65 ° C.) magnetic material 50 parts low molecular weight polypropylene 4 parts Nigrosine dye 2 parts

The above materials were premixed with a Henschel mixer, kneaded with an extruder heated to 150 ° C., cooled, coarsely pulverized with a cutter mill, and further classified with an air classifier to obtain a weight average particle diameter of 10 A fine powder of 0.4 μm was obtained. A toner was obtained by thoroughly mixing 100 parts of this fine powder with 0.4 part of hydrophobic colloidal silica.

The toner obtained as described above was applied to a copying machine NP-3525 manufactured by Canon as an image forming apparatus to obtain a copied image on a high quality paper having a surface roughness Ra of 2.5 μm.

Then, the obtained copied image was passed between two aluminum pressure rollers heated to 200 ° C. having a cleaning mechanism. The above process was repeated 3 times. After this step, the toner was removed from the image receiving paper, and an electrophotographic image receiving sheet capable of repeatedly forming a copied image was obtained.

Example 2 A copied image was obtained in the same manner as in Example 1 except that a PET sheet having a sheet thickness of 100 μm was used as the image receiving sheet. The copied image was passed three times between pressure rollers covered with foamed polyurethane rubber and heated to 180 ° C. The toner was removed from the image-receiving paper after passing, and an image-receiving sheet sufficient to form a copied image was reproduced again.

Example 3 A copied image was obtained in the same manner as in Example 1 except that a copying machine similar to that in Example 1 was used and coated paper having a surface roughness Ra of 0.5 μm was used as the image receiving paper. . The copied image,
The upper roller is covered with polyurethane foam rubber for 150
It was passed through an aluminum roller heated to ° C. The process was repeated twice. Toner was efficiently removed from the image-receiving paper that has undergone this step, and an image-receiving sheet sufficient to form a copied image was regenerated.

Example 4 A classified product having a weight average particle size of 11.2 μm was obtained in the same manner as in Example 1 except that the amount of the magnetic material used in Example 1 was 60 parts, and the hydrophobic substance was added to 100 parts by weight. Colloidal silica 0.
A magnetic toner was obtained by externally adding 4 parts.

A copied image was formed in the same manner as in Example 1 except that the toner obtained above was applied to NP-5540 as an image forming apparatus. The image obtained was passed three times between two rollers coated with a polyvinyl chloride crosslinker and heated to 200 ° C. After passing, the toner was removed from the paper, and the image receiving paper could be recycled.

Example 5 A copied image was obtained in the same manner as in Example 2. This copied image is heated to 180 ° C., and an oil absorbing resin (oleosorb:
It was brought into contact with a sheet filled with Nippon Shokubai. When this step was repeated three times, the toner layer was sufficiently removed and the image receiving sheet was regenerated.

Example 6 As a core substance, 30 parts of a chemical reaction product obtained by reacting 5 g of dimethylaminoethyl methacrylate with 20 parts of polyethylene wax, 20 parts of paraffin wax, 30 parts of carnauba wax, and a particle size of 0. Add 100 parts of 2 μm magnetite to 120
Melt and mix at ℃, granulate with a spray dryer, then strictly classify ultrafine powder and coarse powder at the same time with a multi-division classifier utilizing the Coanda effect (Elbowjet classifier manufactured by Nippon Mining Co., Ltd.) to obtain a weight average particle size of 12 Black fine particles of 0.3 μm were obtained.

Next, the number average molecular weight (Mn) = 840.
The obtained core was dissolved in a dimethylformamide solution in which 15 parts of a styrene-dimethylaminoethyl methacrylate (molar ratio 90/10) copolymer having a value of 0, Mw / Mn = 6.2, and Tg = 70 ° C. were dissolved. Disperse 100 parts of particles,
About 0.34μ by gradually adding water and phase separation
An encapsulated particle coated with a film thickness of m was obtained. A capsule toner was obtained by mixing 100 parts of this fine powder with 1.2 parts of silica fine powder which was hydrophobized with γ-aminopropyltriethoxysilane with a Nauta mixer.

The above-mentioned capsule toner was applied to a modified PC-30 (made by Canon Inc.) as an image forming apparatus to obtain a pressure-fixed copied image. At this time, synthetic paper having a surface roughness Ra of 0.65 μm was used as the image receiving sheet. The copied image was heated to 140 ° C. and passed twice between two magnetic metal rollers each having an upper roller coated with foamed polyurethane rubber. After passing the paper, the toner was sufficiently removed, and the image receiving sheet which could be used for the image formation again was reproduced.

Example 7 Styrene-butyl acrylate-divinylbenzene copolymer 100 parts (copolymerization weight ratio 80/19/1, Mw 68,000, Tg 69 ° C.) magnetic material (average particle size 0.15 μm) 100 parts monoazo dye Metal complexes of 3 parts Low molecular weight polypropylene-ethylene copolymer 4 parts

After thoroughly mixing the above materials with a blender,
It was kneaded by a twin-screw kneading extruder set at 150 ° C. After cooling the obtained kneaded product, after roughly crushing with a cutter mill,
The powder was finely pulverized using a fine pulverizer using a jet stream, and the obtained fine pulverized powder was classified by a fixed wall type air classifier to produce classified powder. Furthermore, the obtained finely divided powder was subjected to strict classification of ultrafine powder and coarse powder at the same time with a multi-division classifier utilizing the Coanda effect (Elbow Jet classifier manufactured by Nittetsu Mining Co., Ltd.) to obtain a weight average particle diameter of 6.2 μm. A black fine powder was obtained. 100 parts of this black fine powder and 0.7 part of silica fine powder treated with silicone oil were mixed with a Henschel mixer to obtain a negatively chargeable magnetic toner.

A laser beam printer LBP-A40 manufactured by Canon Inc. is used as an image forming apparatus using the above negatively chargeable toner.
It was applied to 4 modified machines and a copy image was obtained on a high quality paper having a surface roughness Ra of 2.5 μm. Then, the obtained copy image was passed between two aluminum pressure rollers heated to 200 ° C. having a cleaning mechanism. Further, the image-receiving sheet was pressed and deinked with a magnet roll heated to 150 ° C. The above process was repeated 3 times. After this step, the toner was removed from the image receiving paper, and an electrophotographic image receiving sheet capable of repeatedly forming copied images was obtained.

[0040]

According to the present invention, it is possible to provide a dry deinking technique in which a copied image can be easily deinked and the image receiving sheet can be easily regenerated.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of an outline of an image removal process used in the present invention.

FIG. 2 illustrates another example of the image removal process used in the present invention.

[Explanation of symbols]

 101 image receiving sheet 102 toner image 103 lower roller 104 adsorption roller 201 image receiving sheet 202 toner image 203 lower roller 204 adsorption sheet (belt) 205 upper roller 206 guide roller

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Claims (4)

[Claims] 1. A method for reproducing an image receiving sheet, which comprises removing toner from the surface of the image receiving sheet by adhering or absorbing a toner image recorded on the image receiving sheet. 2. The method of regenerating an image-receiving sheet according to claim 1, wherein the toner image is attached or absorbed by bringing a heated metal roller into contact with the toner image. 3. A toner image is attached or absorbed by bringing a heated roller or belt into contact with the toner image, and the surface of the roller or belt is made of resin.
The method for reproducing the image receiving sheet described in. 4. The toner image is adhered or absorbed by bringing a heated roller into contact with the toner image, and the roller has magnetism. Reproduction method of image receiving sheet.