JPH06102802A - Method and device for treatment of waste toner - Google Patents

Abstract

PURPOSE:To effectively treat the toners (waste toners) which remain on a photosensitive body without being completely transferred onto a body to be transferred by execution of an electrophotographic method and are collected by being removed in the cleaning stage of the photosensitive body. CONSTITUTION:The toners are essentially composed of coloring materials, binder resins and polarity control agents. Such waste toners and materials which biodecompose and/or photodecompose the binder resins in these toners are mixed, by which the waste toners are decomposed. The biodecomposable materials are exemplified by microorganisms and enzyme and the photodecomposable materials are exemplified by compds. having functional groups to absorb light energy, etc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for treating waste toner, and more particularly to a method and an apparatus for treating waste toner collected in a cleaning process of a copying machine, a facsimile, a printer or the like.

[0002]

2. Description of the Related Art In an image forming apparatus employing an electrophotographic system (including an electrostatic recording system and an electrostatic printing system), toner is used to visualize an electrostatic image. This toner is obtained by dispersing a binder and a polarity control agent in a molten binder resin, and pulverizing this into an appropriate size. This toner is used as it is as a one-component developer, mixed with carrier particles and used as a dry two-component developer, or dispersed in a carrier liquid and used as a liquid developer. However, in reality, it is often used as a dry developer of or.

[0003]

By the way, as described above, the toner is composed of the binder resin, the coloring material, the polarity control agent and the like, and the resin occupies a large proportion. recent years,
As the amount of information increases, the number of copies made by the electrophotographic method surely increases, and as a result, a large amount of waste toner is generated. The binder resin in the waste toner is not decomposed unless some treatment is performed, and as a result, the waste toner is gradually accumulated on the earth like plastic waste. Although it is conceivable to incinerate the waste toner, in that case, since high energy is emitted, the incinerator is damaged, and there is a problem in global warming accompanying the incineration. The present invention provides a method and an apparatus for treating waste toner, which solves these problems.

[0004]

The first aspect of the present invention is a method for treating waste toner, which is a waste toner collected in an electrophotographic cleaning process and a substance that decomposes the waste toner (more precisely, " Is a substance that decomposes the "binder resin in the waste toner") to decompose the waste toner.

A second aspect of the present invention is a waste toner processing apparatus, which comprises a first storage portion for storing waste toner to be collected in an electrophotographic cleaning process and a substance for decomposing the waste toner (waste toner decomposing substance). ) For storing waste toner decomposing substance is discharged from the second storage portion to the first storage portion in accordance with the discharge of the waste toner to the first storage portion. It is characterized by doing so.

The inventors of the present invention have studied the method and apparatus for treating waste toner from various angles. (1) Waste toner and substances that decompose the waste toner (biodegradable substance and / or light) The waste toner is decomposed by mixing with (2)
It was confirmed that if the above (1) is performed in the presence of a material that decomposes the waste toner and a material that plasticizes the waste toner, the waste toner is decomposed more effectively. The present invention has been made based on these findings.

The present invention will be described in more detail below. The waste toner targeted by the present invention is no different from the original toner before its use. Therefore, this product is composed of a binder resin in which a colorant and, if necessary, other additives (plasticizer, etc.) are dispersed.

As the binder resin for toner, all the binder resins used in this field can be applied. Specifically, homopolymers of styrene such as polystyrene, polychloroethylene, and polyvinyltoluene and substitution products thereof; styrene-
p-chlorostyrene copolymer, styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene -Methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ether Copolymer, styrene-vinyl ethyl ether copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer, styrene-maleic acid copolymer, styrene-
Styrene-based copolymers such as maleic acid ester copolymers; polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, polyvinyl butyl butyral, polyacrylic acid resin, rosin, modified rosin, Terpene resin, phenol resin, aliphatic or alicyclic hydrocarbon resin, aromatic petroleum resin, chlorinated paraffin,
Paraffin wax and the like may be used, and these may be used alone or in combination of two or more.

As the binder, all of the conventionally used pigments, dyes and polarity control agents can be applied. Specifically, ultramarine, nigrosine dye, aniline blue, chalco oil blue, DuPont oil red, quinoline yellow, methylene blue chloride, phthalocyanine blue,
Phthalocyanine green, Rhodamine 6C rake, quinacridone, benzidine yellow, malacanite green, Hansa yellow G, malachite green hexalate, oil black, azoiol black, rose bengal, monoazo dyes and pigments, disazo dyes, trisazo dyes, Quaternary ammonium salts, metal salts of salicylic acid and salicylic acid derivatives, and mixtures thereof.

As the plasticizer, in addition to synthetic waxes such as low molecular weight polyethylene and polypropylene, plant waxes such as candelilla wax, carnauba wax, rice wax, wood wax and jojoba oil, beeswax and laurin. , Waxes such as whale wax, mineral waxes such as montan wax and ozokerite, and oil-based waxes such as hydrogenated castor oil, hydroxystearic acid, aliphatic amides, and phenol fatty acid esters. Further, in addition to the above components, the toner according to the present invention may be supplemented with auxiliary agents such as various additives (antimony oxide, etc.) for the purpose of adjusting the thermal properties, electrical properties, physical properties, etc. of the toner as required. It is also possible to do so.

When this toner is used as a two-component dry developer, a carrier is required. As the carrier core material, cobalt, iron, copper, nickel, zinc, aluminum, ferrite, magnetite, brass having an average particle size of 20 to 1000 μm, preferably 30 to 100 μm,
Conventionally used materials such as non-metals such as glass, metals and alloys are widely used.

The surface of the carrier core material is usually coated with a resin, and such a resin-coated carrier is produced by a method such as spray coating or dip coating as in the conventional case. If necessary, carbon, metal, titanium oxide, zinc oxide or the like as a conductive substance may be added to the coat layer. Further, a pigment such as phthalocyanine, a quaternary ammonium salt, silica, a dye, a resin, a silane coupling agent, a titanium coupling agent or the like may be added as a charge imparting substance.

Examples of the toner binding resin include, for example,
Polystyrene, chloropolystyrene, poly-α-methylstyrene, styrene-chlorostyrene copolymer, styrene-propylene copolymer, styrene-butadiene copolymer, styrene-vinyl chloride copolymer, styrene-vinyl acetate copolymer, Styrene-maleic acid copolymer, styrene-acrylic acid ester copolymer (styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-
Octyl acrylate copolymer, styrene-phenyl acrylate copolymer, etc.), styrene-methacrylic acid ester copolymer (styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate) Copolymers, styrene-phenyl methacrylate copolymers, etc.), styrene-α-chloromethyl acrylate copolymers, styrene-acrylonitrile-acrylic acid ester copolymers and other styrene resins (including styrene or styrene substitutes) Homopolymer or copolymer), vinyl chloride resin, styrene-vinyl acetate copolymer, rosin-modified maleic acid resin, phenol resin, epoxy resin,
Polyester resin, ionomer resin, polyurethane resin, silicone resin, ketone resin, ethylene-ethyl acrylate copolymer, xylene resin, polyvinyl butyral resin, fluororesin, etc. are available, but these resins may be used alone or in combination of two or more. To be done.

As mentioned above, the toner may be a single component, or may contain magnetic powder depending on the mode of use. As such a magnetic powder, a substance that is magnetized by being placed in a magnetic field is used, and there are powders of ferromagnetic metals such as iron, cobalt and nickel, and alloys and compounds such as magnetite, hematite and ferrite. The content of the magnetic powder is 15 to 70% by weight based on the weight of the toner.

In the present invention, after such toner is used for developing an electrostatic image, the toner remaining on the image carrier is decomposed into toner (waste toner) collected in the cleaning step. It is carried out in the presence of biodegradable substances and / or photodegradable substances.

The biodegradable substance will be described below. The main chain of the polymer (binder resin) is cleaved by microorganisms and enzymes, and the decomposition proceeds, returning it to the carbon cycle of the natural ecosystem. For example, fatty acid polyesters and ethylene-acrylic acid copolymers to which starch is added are decomposed by many microorganisms such as bacterial bacteria, radioactive bacteria and insects. Biodegradation usually occurs in the soil or water in which these microorganisms live. 1) Starch: Microorganisms in the soil destroy starch granules to accelerate the decomposition of the polymer (binder resin in waste toner). 2) Natural polyester: Microorganisms secrete a polyester-degrading enzyme to the outside of the bacterial cell, and the enzyme decomposes the polymer chain of polyester into a low-molecular weight organic acid. Then, the organic acid is taken into the body and used as a nutritional source for life activity, and finally converted into various biopolymers and carbon dioxide. 3) Synthetic polypeptides: Microorganisms secrete polyester-degrading enzymes outside the cells, and the high-molecular chains of polyester are decomposed into low molecular weight organic acids by the enzymes. Then, the organic acid is taken into the body and used as a nutritional source for life activity, and finally converted into various biopolymers and carbon dioxide. 4) Aliphatic polyester: Microorganisms secrete a polyester-degrading enzyme to the outside of the microbial cell, and the enzyme decomposes the polymer chain of the polyester into a low-molecular weight organic acid. Then, the organic acid is taken into the body and used as a nutritional source for life activity, and finally converted into various biopolymers and carbon dioxide.

Specific examples of these include (1) natural polymer-based polysaccharides, trade name ECOSTAR: manufactured by Hagiwara Kogyo Co., Ltd. (2) natural polymer-based natural polyester polyhydroxybutyric acid and its derivatives. For example, poly-3-hydroxybutyrate (3HB) and poly-3-
Copolymer with hydroxyvalerate (3HV) (Biopol manufactured by ICI), poly-3-hydroxybutyrate (3HB) and poly-4-hydroxybutyrate (4H
It may be a copolymer with B), or even these monomers. (3) Synthetic Polypeptide This polypeptide is generally a peptide in which 10 or more amino acids are bonded. Examples thereof include ε-caprolactam, polycaprolactam, aliphatic amino acids, amino acids having an aromatic nucleus, amino acids having a heterocycle, and collagen (hard protein) classified as a natural polypeptide. The polycaprolactam here can be obtained by subjecting ε-polycaprolactam and water to heating in an autoclave type reactor and ring-opening polymerization. (4) Synthesis polyester of aliphatic polyesters CO and formaldehyde and subjected to polymerization at a predetermined temperature in the catalyst under with nitrogen in an autoclave reactor as a starting material glycolide _{[- (CO-CH 2 O} ) 2 1 -] to synthesize . And so on.

As described above, when the biodegradable resin is blended with the waste toner, a sea-island structure (phase-separated structure) is formed, and it is considered that the waste toner is decomposed due to the breakage of the island portion of the biodegradable resin. To be

The photodegradable substance will be described below. Photolysis of plastics begins with the absorption of light energy. Therefore, in order for plastics to undergo photodecomposition, they are decomposed by functional groups that absorb light energy. It is considered that when the waste toner and the photodecomposable substance are blended and exposed to light, the photodegradable substance is decomposed, and as a result, the decomposition of the waste toner itself is accelerated.
Looking at this in the case of an olefin system, olefins are photooxidized by the action of a metal complex, hydroperoxide is introduced into the side chain, and finally a carbonyl group is introduced into the olefin chain, after which ketone photolysis is performed Results in strand breaks.
When such a substance is blended with the waste toner, the decomposition of the photodecomposable substance at the island portion having the sea-island structure is decomposed (cut) to more efficiently decompose the waste toner. 1) Ketone type A polymer having a side chain ketone group is likely to cause cleavage of the main chain. 2) Ethylene / CO system 3) Photosensitizer Metal ions act as a catalyst to promote the decomposition of peroxide or carboxyl group generated from oxygen to the easily attacked part of the polymer chain, and the molecule is cleaved from there. Occurs.

Specific examples of these are as follows. (1) Ketone-based Polymer of vinyl ketone-based monomer (monomer) or copolymer with vinyl-based monomer. Examples of vinyl ketone-based monomers include methyl vinyl ketone, methyl isopropenyl ketone, t-butyl vinyl ketone, ethyl vinyl ketone, phenyl vinyl ketone, divinyl ketone, and chloromethyl vinyl ketone, and examples of vinyl ketone-based monomers include ethylene and styrene. , Methylmethacrylate, vinyl chloride-α-butylmethacrylate, α-methylstyrene, etc., and the commercial products include Ecdyte (Eco pla
Stics). (2) Ethylene / CO system CH ₂ ═CH ₂ and CO as raw materials in an autoclave type reactor using di-t-butyl peroxide as a catalyst
A polymer was obtained by reacting at 133 ° C. at ℃. _{[- (CO-CH 2 CH} 2) n-] is liable molecular chain scission is extremely caused because having ketone group in the main chain. As an example of this product, ECO (Union C
abite). (3) Photosensitizer Examples of photosensitizers include metal diethylcarbamate iron, iron (III) acetylacetate, stearic acid metal salt, anthraquinone and its derivatives, thiodipropionic acid, benzophenone and its derivatives, polypropylene and poly. Examples include isobutylene and polymethacrylate.

When the binder resin of the toner is a polymer that is hard and rigid by itself, a material that plasticizes the waste toner is blended with the waste toner to impart flexibility, elasticity, processability and the like. Is advantageous. As a material for plasticizing such waste toner, an organic substance having low volatility is generally suitable. Especially in the case of vinyl chloride resin,
Since a material that plasticizes the waste toner is added within the range of up to 50% and is often used as a flexible elastic body at room temperature,
Its softening action is extremely important. There have been many studies on the mechanism of improving such plasticity of such plasticized materials. For example, the lubrication theory of reducing the friction between molecules as well as the lubricant, and the intermolecular interaction in some linear polymers. There is one that forms a network structure (such as vinyl chloride resin) due to a weak bond that acts on, and there is a gel theory that a plasticizer disturbs the three-dimensional network structure.

The plasticizer industry has grown up with the development of cellulose derivatives, but with the recent remarkable growth of vinyl chloride resins, a wide range of compounds have come to the market. However, it is the dibasic acid ester, especially the phthalic acid ester, which is the most widely consumed and industrially consumed in the industry. Further, when it is difficult or unfavorable to plasticize a rubber, especially a synthetic rubber, only by a mechanical action, a plasticizer is often added.

The conditions for the material for plasticizing the waste toner in the present invention are (1) good plasticization efficiency, that is, plasticity is improved by adding a small amount and sufficient flexibility is given ( 2) High plasticization rate, (3) Good compatibility (miscibility), (4) Low volatility, (5) No migration, (6) No loss of flexibility even at low temperature (Cold resistance), (7) Good water and oil resistance, (8) Good heat and light resistance, chemically stable, (9) Good electrical insulation, (10) Difficult It is required to be flammable, (11) colorless, tasteless, odorless and nontoxic, and (12) inexpensive. However, since no plasticizing material satisfying all of them is found, it is desirable to use a mixture of two or more kinds of plasticizing materials and simultaneously reduce the price. In that case, a material having a large plasticizing effect and used in a large amount is called a primary plasticizer, and an auxiliary material is used as a secondary plasticizer.
ary plasticizer).

Specific examples thereof include 1) phthalic acid derivative dibutyl phthalate and di-n-octyl phthalate 2) adipic acid derivative di-n-butyl adipate 3) azelaic acid derivative di- (2-ethylhexyl) azelate 4) Sebacic acid derivative dimethyl sebacate 5) Maleic acid derivative di-n-butyl maleate 6) Fumaric acid derivative dibutyl fumarate 7) Trimellitic acid derivative tri- (2-ethylhexyl) trimellitate 8) Citric acid derivative triethyl citrate 9) Oleic acid derivative Methyl oleate 10) Ricinoleic acid derivative Methyl acetyl lycilute 11) Stearic acid derivative n-Butyl stearate 12) Sulfonic acid derivative Benzene sulfone butylamide 13) Phosphoric acid derivative Triethyl pho Feto 14) glycol derivative triethylene glycol di - (2-ethyl butyrate) 15) Glycerol derivatives glycerol monoacetate 16) paraffin derivatives chlorinated paraffins 17) diphenyl derivatives chlorinated diphenyl 18) epoxy derivatives epichlorohydrin and the like.

When carrying out the method of the present invention, a first storage section for storing waste toner and a second storage section for storing a substance that decomposes the waste toner are separately provided, and the first storage section is provided. It is advantageous to employ an apparatus that discharges the waste toner decomposed substance from the second storage portion to the first storage portion in accordance with the discharge of the waste toner to the storage portion.

[0026]

EXAMPLES Next, the present invention will be described more specifically with reference to examples. The parts here are based on weight.

Example 1 As a carrier for a two-component developer, the average particle size is about 100 μm.
m steel beads (Shinto Blator Microshot S
F-100) was prepared. In addition, the mixture of the following prescription
The mixture was kneaded under heating on this roll, cooled, and then pulverized and classified to prepare a two-component developing toner having a particle size of 5 to 20 μm. Polystyrene (D-125 manufactured by Esso) 100 parts Metallic dye (Spiron Black BH manufactured by Hodogaya Chemical Co., Ltd.) 5 parts Carbon black (# 44 manufactured by Mitsubishi Kasei) 10 parts 100 parts of these carriers and 3.0 parts of toner A two-component developer was prepared by mixing. The charge amount (Q / M) of the toner by the blow-off method in this developer is -16.
It was μc / g.

On the other hand, the apparatus of the present invention will be described below in connection with the copying process with reference to the attached drawing (FIG. 1). First, the surface of the photoconductor 1 is uniformly charged with positive or negative charges by the charging charger 2. Positive charging or negative charging is selected depending on the type (property) of the photosensitive member 1. For example, if the photosensitive member is of the photosensitive member Se type, positive charging is performed. Image exposure is performed on this by the optical system 3 to form an electrostatic charge image, and the electrostatic charge image is visualized in the developing section 4. The developing unit 4 contains a two-component developer including a carrier (magnetic carrier) and a toner (developing toner). The developer is a developing sleeve 4 having a built-in magnet 411.
The electrostatic charge image of the photoconductor 1 held on the surface 1 is developed. Since only the developing toner is consumed each time development is performed, the sensor 42 detects the toner concentration of the developer, and new developing toner is supplied so that the toner concentration is always constant. 43 is a paddle wheel for stirring the developer. A bias may be applied to the developing sleeve 41 if necessary. The visible image (toner image) is transferred to the transfer paper 8 by the transfer charger 5, and the transfer paper 8 is separated from the photoconductor 1 by the separation charger 6 and the separation claw 9 and sent to the fixing step. As mentioned above, all of the toner forming a visible image on the photoconductor 1 at the time of transfer is not transferred to the transfer paper 8 and a part thereof remains on the photoconductor 1. Then, the residual toner is removed by the cleaning unit 7. The cleaning unit 7 holds the cleaning blade 11 in the holder 10 and cleans the upper part 1 with 11. The cleaned toner is discharged to the first storage portion 16 by the transport coil 12 as waste toner. A toner decomposable substance (starch) is stored in the second storage portion 13. Reference numeral 14 is a transfer coil.

As shown in FIGS. 2 and 3, the carrier coil 12 is connected to the coil drive gear 15, and the carrier coil 14 is also linked by the gear so that the carrier coil 12 and the carrier coil 12 are integrally linked. As a result, the two items are discharged to the first storage unit 16. The motor 15 rotates the gear 15, the gear 18, and the gear 19.

The surface of the photosensitive member 1 was uniformly charged to +800 V, and copying was performed at a rate of 30 sheets per minute to collect the waste toner. This mixture of waste toner and starch (for convenience, called “waste toner”) was filled in Kanuma soil for 4 months and then taken out, and the toner was loose and shattered (like crap). It was a grain. This is the deterioration in strength that accompanies the decomposition of the toner. When this product was passed through a 16-mesh (1000 μm) sieve, the waste toner passed through the sieve, and the waste toner was decomposed into the form contained in Kanuma soil.

Examples 2 to 7 When the starch of Example 1 was replaced with the substances shown in Table 1 and waste toner was obtained in the same manner as in Example 1 and subjected to the same test, the same results as in Example 1 were obtained. It was

[0032]

[Table 1]

Example 8 After the same amount of the starch of Example 1 and di-n-octyl phthalate were kneaded on a two-roll mill, pulverized and classified, and set in the second storage unit 13, the same waste toner as in Example 1 was used. After collecting, the waste toner became dango-like and the effect of the plasticizing material was recognized, and sufficient mixing was in progress. 3 this toner
After soaking it in the soil for a month, when I took it out and saw it, the toner was in the form of tiny particles that were tattered and shattered. This is the strength deterioration of the toner accompanying the toner deterioration.

Comparative Example Even if the waste toner alone was simply immersed in the soil for 4 months, the toner could not be decomposed at all.

Examples 9-14 The starch or di-n-octyl phthalate of Example 8 is listed in Table 2.
When replaced with the one shown in, the same results as in Example 8 were obtained.

[0036]

[Table 2]

[0037]

According to the first and second aspects of the invention, the waste toner is effectively treated. According to the description of claim 3, the waste toner is processed more effectively. According to the description of claim 4, the processing of the waste toner can be performed smoothly.

[Brief description of drawings]

FIG. 1 is a diagram showing an outline of a main part of a device of the present invention.

FIG. 2 is a diagram showing how waste toner is discharged to a storage unit.

FIG. 3 is a diagram showing a driving unit for adding a waste toner decomposable substance to waste toner.

[Explanation of symbols]

1 Image Carrier 2 Charging Charger 3 Optical System 4 Developing Section (41 Developing Sleeve 411 Magnet) 5 Transfer Charger 6 Separation Charger 7 Cleaning Section (10 Holder 11 Cleaning Blade 12 Transport Coil 13 Second Storage Section 14 Transport Coil 15 Drive Gear 16 1st storage section 17 Motor 18 gear 19 gear 20 gear) 8 Transfer paper 9 Separation guide plate

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tomio Kondo 1-3-6 Nakamagome, Ota-ku, Tokyo Stock company Ricoh Co., Ltd. (72) Chiharu Mochizuki 1-3-6 Nakamagome, Ota-ku, Tokyo Shares Within Ricoh Company (72) Inventor Shinichi Kuramoto 1-3-6 Nakamagome, Ota-ku, Tokyo Within Ricoh Company, Ltd.

Claims (4)

[Claims] 1. A method of treating waste toner, characterized in that waste toner collected in an electrophotographic cleaning process is mixed with a substance that decomposes a binder resin in the waste toner to decompose the waste toner. 2. The method for treating waste toner according to claim 1, wherein a biodegradable substance and / or a photodegradable substance is used as a substance that decomposes the binder resin in the waste toner. 3. The method for treating waste toner according to claim 1, wherein a substance that decomposes the binder resin in the waste toner is mixed with a material that plasticizes the waste toner. 4. A first storage section for storing waste toner collected in an electrophotographic cleaning process, and a second storage section for storing a substance that decomposes the waste toner are provided. And processing the waste toner into the first storage portion so as to discharge the substance that decomposes the waste toner from the second storage portion in accordance with the discharge of the waste toner into the first storage portion. apparatus.