JP3245625B2 - Waste toner treatment method and apparatus - Google Patents

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 and 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 controlling agent in a molten binder resin and pulverizing the dispersion 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, the fact is that it is often used as or as a dry developer.

[0003]

As described above, the constitution of the toner is composed of a binder resin, a coloring material, a polarity control agent, and the like, and the ratio of the resin is large among them. recent years,
As the amount of information increases, the number of electrophotographic copies increases steadily, and as a result, a large amount of waste toner is generated. The binder resin in the waste toner does not decompose unless subjected to any treatment, and as a result, there is a disadvantage that the waste toner gradually accumulates on the earth like the plastic waste. Of course, it is conceivable to incinerate the waste toner. However, in such a case, high energy is generated, which damages the incinerator and causes a problem of global warming accompanying incineration. SUMMARY OF THE INVENTION The present invention provides a method and an apparatus for treating waste toner that have solved such problems.

[0004]

According to the present invention, the following is provided.
An invention is provided . (1) A method of decomposing waste toner collected in a cleaning step in an electrophotographic method comprising a series of operations.
Oite, a mixture of substances which decompose the binder resin in the waste toner in the waste toner, decomposing the binder resin of the mixed waste toner
By decomposing the substance to be thereby cracking process of the waste toner, wherein the allowed to decompose the waste toner. (2) material to decompose the binder resin in the waste toner, wherein (1) the decomposition treatment process of waste toner, wherein the biodegradable material and / or photodegradable material. (3) the substance to degrade the binder resin in the waste toner, and characterized by mixing the material allowed to plasticize the waste toner
The method for decomposing waste toner according to the above (1) .

[0005]Further, according to the present invention, the following inventions are provided.
Provided.  (4) In the electrophotographic apparatus, the cleaning process
A first storage unit for storing waste toner to be collected, and a waste toner
And a second storage section for storing a substance that decomposes
And discharge of waste toner to the first storage unit.
A material that disassembles waste toner from the second storage unit
Discharges the quality into the first compartmentWaste toner
With processing equipmentCharacterized byElectrophotographic equipment.

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

Hereinafter, the present invention will be described in more detail. Before use, the waste toner targeted by the present invention does not differ from the original toner at all. Therefore, this is made of a binder resin in which a coloring material and, if necessary, other additives (such as a plasticizer) are dispersed.

[0008] As the binder resin for toner, all of those used in this field can be applied. Specifically, a homopolymer of styrene such as polystyrene, polychloroethylene, and polyvinyl toluene and a substituted product 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 copolymers such as maleic ester copolymers; polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, polyvinyl butyl butyral, polyacrylic resin, rosin, modified rosin, Terpene resin, phenolic resin, aliphatic or alicyclic hydrocarbon resin, aromatic petroleum resin, chlorinated paraffin,
Examples thereof include paraffin wax, and these may be used alone or in combination of two or more.

As the binder, all of conventionally used pigments, dyes and polarity controlling agents can be applied. Specifically, ultramarine, nigrosine dye, aniline blue, calco oil blue, Dupont oil red, quinoline yellow, methylene blue chloride, phthalocyanine blue,
Phthalocyanine green, rhodamine 6C lake, quinacridone, benzidine yellow, malacanite green, hansa yellow G, malachite green hexalate, oil black, azoiol black, rose bengal, monoazo dye, disazo dye, trisazo dye, Examples include quaternary ammonium salts, metal salts of salicylic acid and salicylic acid derivatives, and mixtures thereof.

Examples of the plasticizer include synthetic waxes such as low molecular weight polyethylene and polypropylene, and vegetable waxes such as candelilla wax, carnauba wax, rice wax, wood wax, jojoba oil, beeswax and laurin. And mineral waxes such as montan wax and ozokerite, oil-based waxes such as hydrogenated castor oil, hydroxystearic acid, aliphatic amides and phenol fatty acid esters. Further, in addition to the above components, auxiliaries such as various additives (such as antimony oxide) may be added to the toner according to the present invention, if necessary, in order to adjust the thermal, electrical, and physical properties of the toner. It is also possible.

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 diameter 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.

[0012] The surface of the carrier core material is usually coated with a resin, and such a resin-coated carrier is manufactured by a method such as spray coating or dip coating as in the prior art. 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-acrylate 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) Styrene-based resins (including styrene or styrene-substituted copolymers) such as copolymers, styrene-phenyl methacrylate copolymers, styrene-α-methyl methyl acrylate copolymers, styrene-acrylonitrile-acrylate copolymers, etc. Homopolymer or copolymer), vinyl chloride resin, styrene-vinyl acetate copolymer, rosin-modified maleic resin, phenol resin, epoxy resin,
There are polyester resin, ionomer resin, polyurethane resin, silicone resin, ketone resin, ethylene-ethyl acrylate copolymer, xylene resin, polyvinyl butyral resin, fluorine resin, etc., but these resins are used alone or as a mixture of two or more. Is done.

As mentioned above, the toner may be used as a single component, or may contain a magnetic powder depending on the use mode. As such magnetic powder, a substance that is magnetized when placed in a magnetic field is used, and examples thereof include ferromagnetic metal powders 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 subjected to the development of an electrostatic image, the toner (waste toner) recovered in the cleaning step of the toner remaining on the image carrier is decomposed. It is performed in the presence of a biodegradable substance and / or a photodegradable substance.

Here, the biodegradable substance will be described as follows. The main chain of the macromolecule (binder resin) is cut by microorganisms and enzymes, and decomposition progresses, returning to the carbon cycle of the natural ecosystem. For example, fatty acid polyesters and ethylene-acrylic acid copolymers obtained by adding starch are decomposed by many microorganisms such as bacteria, radioactive bacteria and insects. Biodegradation usually occurs in the soil or water in which these microorganisms live. 1) Starch: Microorganisms in the soil break down starch granules to accelerate the decomposition of the polymer (binder resin in waste toner). 2) Natural polyester: Microorganisms secrete an enzyme that degrades polyester outside the cells, and decomposes the high-molecular-weight polyester chain into low-molecular-weight organic acids. Then, the organic acid is taken into the body and used as a nutrient source for life activity, and finally converted into various biopolymers and carbon dioxide. 3) Synthetic polypeptide: Microorganisms secrete an enzyme that degrades polyester outside the cells, and decomposes the high-molecular-weight polyester chain into low-molecular-weight organic acids by the enzyme. Then, the organic acid is taken into the body and used as a nutrient source for life activity, and finally converted into various biopolymers and carbon dioxide. 4) Aliphatic polyester: Microorganisms secrete an enzyme that degrades polyester outside the cells, and degrades the polymer chain of the polyester into low-molecular-weight organic acids by the enzyme. Then, the organic acid is taken into the body and used as a nutrient source for life activity, and finally converted into various biopolymers and carbon dioxide.

Specific examples thereof include (1) natural polymer-based polysaccharides, trade name ECOSTAR (Ecostar): manufactured by Hagiwara Industry Co., Ltd. (2) natural polymer-based natural polyester polyhydroxybutyric acid and derivatives thereof. 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
A copolymer with B), and further, these monomers may be used. (3) Synthetic polypeptide This polypeptide is generally one in which 10 or more amino acids are peptide-bonded. Examples thereof include ε-caprolactam, polycaprolactam, aliphatic amino acids, amino acids having an aromatic nucleus, amino acids having a heterocyclic ring, collagen (hard protein) classified as a natural polypeptide, and the like. Here, polycaprolactam can be obtained by heating ε-polycaprolactam and water in an autoclave reactor and conducting 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 the decomposition of the waste toner is considered to be promoted by the cutting accompanying the decomposition of the island portion of the biodegradable resin. Can be

Next, the photodegradable substance will be described as follows. Photodecomposition of plastics begins by the absorption of light energy. Therefore, plastics are decomposed by a functional group that absorbs light energy to cause photodecomposition. It is considered that when irradiated with light after blending the waste toner and the photodegradable substance, 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 olefins, olefins are photooxidized by the action of metal complexes, hydroperoxides are introduced into the side chains, and finally carbonyl groups are introduced into the olefin chains. This results in chain scission.
When such a substance is blended with the waste toner, the decomposition (cutting) of the photodegradable substance in the island portion having the sea-island structure causes the decomposition of the waste toner to proceed more efficiently. 1) Ketone-based polymers having a side-chain ketone group are liable to break the main chain. 2) Ethylene / CO system 3) Photosensitizer The metal ion catalyzes the decomposition of the peroxide and carboxyl groups generated from oxygen on the easily attacked portion of the polymer chain, and cleaves the molecule therefrom. Occurs.

Examples of these are as follows. (1) Ketone-based polymer (monomer) of vinyl ketone-based monomer or copolymer with vinyl-based monomer. Examples of vinyl ketone 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 monomers include ethylene and styrene. , Methyl methacrylate, vinyl chloride-α-butyl methacrylate, α-methylstyrene, and the like. Commercially available products include Ecdyte (Ecopla) comprising a styrene-vinyl ketone copolymer.
sics). (2) Ethylene / CO system CH ₂ ＣＨCH ₂ and CO were used as raw materials, and di-t-butyl peroxide was used as a catalyst in an autoclave reactor to form 135.
A polymer was obtained by reacting at 133 ° C. at 133 ° C. _{[- (CO-CH 2 CH} 2) n-] is liable molecular chain scission is extremely caused because having ketone group in the main chain. ECO (Union C
abite). (3) Photosensitizer Examples of photosensitizers are iron metal diethylcarbamate, iron (III) acetyl acetate, metal stearate, 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 hard and rigid polymer per se, a material for plasticizing the waste toner is blended with the waste toner to impart flexibility, elasticity, workability, and the like. Is advantageous. As a material for plasticizing such waste toner, a low-volatile organic substance is generally suitable. In the case of vinyl chloride resin, in particular,
Since a material that plasticizes waste toner is added in the range of 50% to 50% and is often used as a flexible elastic body at normal temperature,
Its softening action is very important. There have been many studies on such plasticity improving mechanisms of plasticized materials. For example, lubricity theory that lowers intermolecular friction like lubricants, and intermolecular There is a gel theory that a plasticizer disturbs the three-dimensional network structure of some (such as a vinyl chloride resin) due to a weak bond acting on the three-dimensional network structure.

Although the plasticizer industry grew with the development of cellulose derivatives, a recent widespread growth of vinyl chloride resins has led to a wide range of compounds being marketed. However, the most widespread and most industrially consumed are dibasic esters, especially phthalates. Further, when it is difficult or disadvantageous to plasticize rubber, especially synthetic rubber, only by mechanical action, a plasticizer is often added.

The conditions for the material for plasticizing the waste toner according to the present invention include (1) good plasticizing efficiency, that is, plasticity is improved by adding a small amount, and sufficient flexibility is given; 2) Fast plasticization rate, (3) Good compatibility (miscibility), (4) Low volatility, (5) No migration, (6) No loss of flexibility even at low temperatures. (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, non-toxic, (12) inexpensive, and the like. However, since there is no plasticized material that satisfies all of them, it is desirable to use a mixture of two or more plasticized materials and simultaneously reduce the price. In this case, a plasticizer having a large plasticizing effect and used in a large amount is referred to as a primary plasticizer (primary plasticizer), and a secondary plasticizer (secondary plasticizer) is used as an auxiliary plasticizer.
aryplasticizer).

Specific examples thereof include: 1) phthalic acid derivative dibutyl phthalate, 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 malate 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 resilate 11) Stearic acid derivative n-butyl stearate 12) Sulfonic acid derivative Benzenesulfone butylamide 13) Phosphoric acid derivative Triethyl 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.

In 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 for decomposing waste toner are separately provided, and the first storage section is provided. It is advantageous to employ an apparatus that discharges waste toner decomposed substances from the second storage section to the first storage section in accordance with discharge of waste toner to the storage section.

[0026]

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 diameter was about 100 μm.
m steel beads (Micro Shot S manufactured by Shinto Breiter Co., Ltd.)
F-100) was prepared. In addition, a mixture of the following formulation
The mixture was kneaded under heating on a roll, cooled, and pulverized and classified to prepare a two-component developing toner having a particle size of 5 to 20 μm. 100 parts of polystyrene (D-125, manufactured by Esso Corporation) 5 parts of metal-containing dye (Spilon Black BH, manufactured by Hodogaya Chemical Co., Ltd.) 5 parts 10 parts of carbon black (# 44 manufactured by Mitsubishi Kasei Corporation) 100 parts of these carriers and 3.0 parts of toner By mixing, a two-component developer was prepared. The charge amount (Q / M) of the toner in the developer by the blow-off method is -16.
μc / g.

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

As shown in FIGS. 2 and 3, the transfer coil 12 is connected to a coil drive gear 15, and the transfer coil 14 is also connected by the gear and integrally works with the transfer coil 12. As a result, two things are discharged to the first storage section 16. The gear 15, the gear 18, and the gear 19 are rotated by the motor 17.

The photoreceptor 1 was uniformly charged so as to have a voltage of +800 V, and was copied at a rate of 30 sheets per minute to collect waste toner. A mixture of this waste toner and starch (called "waste toner material" for convenience) was buried in Kanuma soil for 4 months and then taken out and found that the toner was dislodged and fine It was a grain. This is a deterioration in strength due to decomposition of the toner. When this product was sieved through a 16 mesh (1000 μm) sieve, the waste toner passed through the sieve, and the waste toner was decomposed and contained in Kanuma soil.

Examples 2 to 7 Waste toner was obtained in the same manner as in Example 1 except that the starch of Example 1 was changed to the substances shown in Table 1, and the same test was performed. The same results as in Example 1 were obtained. Was.

[0032]

[Table 1]

Example 8 Equal amounts of the starch and di-n-octyl phthalate of Example 1 were kneaded on a two-roll mill, pulverized and classified, and set in a second storage unit 13 to obtain the same waste toner as in Example 1. When the waste toner was collected, the waste toner became dango-like, and the effect of the plasticizing material was recognized, and sufficient mixing was in progress. 3
After burying in the soil for a month, the toner was found to be fine and grainy as if it were taken out. This is the strength deterioration of the toner accompanying the deterioration of the toner.

Comparative Example Even if only waste toner was simply buried in soil for four months, the toner could not be decomposed at all.

Examples 9 to 14 The starch or di-n-octyl phthalate of Example 8 is shown in Table 2.
And the same results as in Example 8 were obtained.

[0036]

[Table 2]

[0037]

According to the first and second aspects of the present invention, waste toner is effectively treated. According to the third aspect, the waste toner is more effectively treated. According to the fourth aspect, the processing of the waste toner can be performed smoothly.

[Brief description of the drawings]

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

FIG. 2 is a diagram illustrating a state where waste toner is discharged to a storage unit.

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

[Explanation of symbols]

REFERENCE SIGNS LIST 1 image carrier 2 charging charger 3 optical system 4 developing unit (41 developing sleeve 411 magnet) 5 transfer charger 6 separation charger 7 cleaning unit (10 holder 11 cleaning blade 12 transport coil 13 second storage unit 14 transport coil 15 drive gear 16 first storage section 17 motor 18 gears 19 gears 20 gears 8 transfer paper 9 separation guide plate

──────────────────────────────────────────────────続 き Continued on the front page (72) Fumio Kondo 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd. (72) Inventor Chiharu Mochizuki 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Company, Ltd. (72) Inventor Shinichi Kuramoto 1-3-6, Nakamagome, Ota-ku, Tokyo Inside Ricoh Company, Ltd. (56) References JP-A-3-249833 (JP, A) JP-A Sho52 -82774 (JP, A) JP-A-4-179967 (JP, A) JP-A-5-64780 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03G 21/00 G03G 21/10-21/12 G03G 9/00-9/18

Claims (4)

(57) [Claims] 1. A process for decomposing waste toner collected in a cleaning step in an electrophotographic method comprising a series of operations.
In the method, the waste toner is mixed with a substance capable of decomposing the binder resin in the waste toner, and the binder resin in the mixed waste toner is mixed.
By decomposing the material to degrade, thereby cracking process of the waste toner, wherein the allowed to decompose the waste toner. 2. A substance capable of decomposing a binder resin in waste toner.
But biodegradable material and / or degradation treatment method of the waste toner according to claim 1, characterized in that the photodegradable substance. 3. A method for mixing a material for decomposing a binder resin in a waste toner with a material for plasticizing the waste toner.
The method for decomposing waste toner according to claim 1, wherein: 4. An electrophotographic apparatus, comprising: a first storage unit for storing waste toner collected in a cleaning step; and a second storage unit for storing a substance that decomposes the waste toner. In addition, in accordance with the discharge of the waste toner to the first storage unit, the waste storage device configured to discharge the substance capable of decomposing the waste toner from the second storage unit to the first storage unit .
Electrophotographic apparatus having a processing unit
Place .