JPH1124288A - Method for reclaiming organic photoreceptor drum - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the method for reclaiming the organic photoreceptor by perfectly removing a photosensitive layer through a simple and easy process from the used organic photoreceptor without impairing the surface of a conductive substrate. SOLUTION: The used photosensitive layer is removed from the used organic photoreceptor(OPC) drum in which a photosensitive layer is formed on the conductive substrate, by using an aprotic polar solvent having a dielectric constant of >=20, and a dipole moment of >=3, and then, washed with refined water, and again, a new photosensitive layer is formed. It is preferred to use dimethylsulfoxide as this aprotic polar solvent, and it is preferred to use a mixture of dimethylsulfoxide and an inorganic acid as a solvent containing this aprotic polar solvent, and it is preferred that the solvent used for removing the the photosensitive layer is distilled and reused.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a method for regenerating an organic photosensitive drum by removing a photosensitive layer from a used organic photosensitive drum used for image formation and reusing the conductive substrate.

[0002]

2. Description of the Related Art A photosensitive drum having a photosensitive layer containing an organic photoconductor used in an electrophotographic apparatus such as a copying machine or a laser printer (hereinafter, referred to as "OPC drum").
Are treated as consumables. However, OPC
The photosensitive layer, which is used for making a copy image and has a limited life, is mainly used for a drum, and its conductive substrate can be recycled to save resources and reduce production costs. As one example, JP-A-8-286394 discloses that an OPC drum is immersed in an organic solvent composed of a mixed solvent of a lower alcohol and an organic solvent capable of dissolving a photosensitive coating film, and then immersed in hot water and cold water sequentially. Thus, a method of peeling a photosensitive coating film has been disclosed.

[0003]

However, it is difficult to remove the photosensitive layer sufficiently to such an extent that the conductive substrate can be reused by the above-mentioned method of peeling the photosensitive layer using an organic solvent. In addition, the treatment method requires a large amount of solvent, and thus has problems such as safety due to the solvent used, treatment of waste liquid, and adverse effects on the environment.

The present invention has been made to solve the above-mentioned problems in the prior art. That is, an object of the present invention is to completely remove a photosensitive layer from a used OPC drum to a reusable level by a simple and easy method without damaging the surface of a conductive substrate,
OPC for forming a new photosensitive layer on the obtained conductive substrate
An object of the present invention is to provide a method for playing a drum. It is another object of the present invention to provide a method for regenerating used OPC drums at low cost while reducing waste and conserving resources.

[0005]

According to the method of regenerating an OPC drum of the present invention, a used OPC drum having a photosensitive layer on a conductive substrate is used.
The photosensitive layer was removed from the PC drum using a solvent containing an aprotic polar solvent having a dielectric constant of 20 or more and a dipole moment of 3 or more, and then washed with purified water, and then washed again. It is characterized in that a new photosensitive layer is formed. In the method for regenerating an OPC drum of the present invention, when an undercoat layer made of an organometallic compound is provided on the surface of the conductive substrate, the undercoat layer is left after the OPC drum has been used. It is preferable that the photosensitive layer is removed and a new photosensitive layer is formed again and used as a regenerated OPC drum.

[0006] As the aprotic polar solvent in the present invention, dimethyl sulfoxide is preferably used. Further, as the solvent containing the aprotic polar solvent, it is preferable to use a mixture of dimethyl sulfoxide and an inorganic acid. Furthermore, the solvent used in the present invention is preferably reused by distillation.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. According to the present invention, at least a photosensitive layer is formed on a conductive substrate made of a tubular body such as aluminum or stainless steel, and the photosensitive layer is removed from a used OPC drum that has become defective. In this method, the conductive substrate is reused, and a new photosensitive layer is formed thereon to reproduce the OPC drum. In the present invention, the OPC
In order to remove the photosensitive layer of the drum, a method of immersing the photosensitive layer in a solvent containing an aprotic polar solvent to remove the photosensitive layer is employed.However, a method of applying ultrasonic waves or using a blade or a brush is used. Alternatively, a method of mechanically rubbing may be used.

In the present invention, the aprotic polar solvent used for removing the photosensitive layer has a high dielectric constant and a high dipole moment, and has a dielectric constant of at least 20 and a dipole moment. Must have 3 or more, and specifically, dimethyl sulfoxide (dielectric constant 48.9, dipole moment 4.3), dimethylformamide (dielectric constant 36.7,
Dipole moment 3.82), dimethylacetamide (dielectric constant 37.8, dipole moment 3.72), acetonitrile (dielectric constant 37.5, dipole moment 3.4)
4), tetramethylurea (dielectric constant: 23.06, dipole moment: 3.47) and the like, among which dimethyl sulfoxide is preferably used.

This dimethyl sulfoxide (DMSO)
Has a high dielectric constant and a dipole moment as described above,
Because of its high proton-accepting ability, it has excellent penetration and dissolving power, is effective for peeling off coatings and adhesives, and has a high boiling point (189 ° C) and flash point (95 ° C). , Can improve safety issues and environmental impact.

According to the present invention, when DMSO is used as the aprotic polar solvent having a dielectric constant of 20 or more and a dipole moment of 3 or more, the above-mentioned excellent properties of DMSO are utilized to improve the OPC. Since the photosensitive layer of the drum can be removed, it is possible to achieve an excellent effect of removing the photosensitive layer, safety, and effects on the environment, which cannot be obtained by the conventional organic solvent peeling method. In the present invention, as the solvent containing an aprotic polar solvent having a dielectric constant of 20 or more and a dipole moment of 3 or more, the aprotic polar solvent described above, particularly DMS
O may be used alone, or may be used in combination with another solvent.

Other solvents include, for example, aromatic solvents such as toluene and chlorobenzene, alcohol solvents such as n-butanol, benzyl alcohol and isopropyl alcohol, ketone solvents such as cyclohexanone and methyl ethyl ketone, dioxane and tetrahydrofuran. Other aprotic solvents such as ether solvents, ethyl acetate, ester solvents such as n-butyl acetate, aliphatic halogenated hydrocarbon solvents such as methylene chloride, hexamethylphosphonylamide, nitromethane and N-methylpyrrolidone In addition to polar solvents, water, and the like, inorganic acids such as hydrochloric acid, nitric acid, sulfuric acid, hydrobromic acid, perchloric acid, and phosphoric acid, and organic acids such as trifluoroacetic acid, formic acid, acetic acid, toluenesulfonic acid, and lactic acid are given. Can be used alone or in combination of two or more. That. The mixing ratio when the aprotic polar solvent and the other solvent are mixed and used is 100 parts by weight of the aprotic polar solvent, and the other solvent is in a range of 1 to 100 parts by weight, preferably 5 to 100 parts by weight. It is in the range of 80 parts by weight.

As a solvent used in the present invention, a solution obtained by mixing DMSO and an inorganic acid can be used as a charge-generating material in addition to a curable resin such as a polyurethane resin or an epoxy resin. Since the solubility of the pigment is increased, it is more suitable for removing the photosensitive layer. DMS
The amount of the inorganic acid mixed with O is 50% by weight or less, preferably 1 to 40% by weight of the inorganic acid per 100 parts by weight of DMSO.
Range. In order to increase the efficiency of removing the photosensitive layer of the OPC drum, the solvent containing DMSO is required to be 3
It is preferable to use by heating to 0 to 180 ° C.

In the present invention, the solvent containing DMSO used for removing the photosensitive layer can be reused by subjecting it to a purification treatment by distillation.
It is preferable to recycle the used DMSO by distilling and purifying it from the viewpoints of environmental conservation and resource saving, since waste liquid treatment and the cost of purchasing DMSO can be reduced.
More economical.

According to the present invention, after the photosensitive layer is removed, the conductive substrate is subjected to finish cleaning by ultrasonic cleaning, brush cleaning, water jet cleaning, rinsing cleaning or the like using purified water such as ion-exchanged water or distilled water. This makes it possible to completely remove DMSO, dust, and the like attached to the conductive substrate. Further, the OPC drum from which the photosensitive layer has been removed according to the present invention can be replaced with a new OPC drum having electrophotographic characteristics similar to that of a new one by forming a photosensitive layer thereon.
It can be reused as a PC drum.

[0015]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. In the following examples, “parts” means “parts by weight”. Example 1 An aluminum pipe of 30 mmφ × 253 mm was prepared as a substrate of a photoreceptor. A 1.0 μm-thick undercoat layer was formed on the surface of the substrate by a dip coating method in which the substrate was immersed in a methanol / butanol mixed solution of 8-nylon resin (lactamide, manufactured by Dainippon Ink and Chemicals, Inc.). . On the other hand, 1 part of a polyvinyl butyral resin (Eslec BM-1, manufactured by Sekisui Chemical Co., Ltd.) is dissolved in 19 parts of cyclohexanone, and 8 parts of a dibromoanthanthrone pigment (CI Pigment Red 168) and 8 parts of 0.02 parts of trifluoroacetic acid were added. Then
Using 1 mmφ glass beads as a dispersion medium, dispersion treatment was performed by a sand mill. To the obtained dispersion, cyclohexanone was further added to prepare a coating solution having a solid content of 10%, and this coating solution was coated on the undercoat layer formed as described above using a ring coating machine. This was dried by heating at 100 ° C. for 10 minutes to form a charge generation layer having a thickness of 0.8 μm. Next, N. N'-diphenyl-N, N'-bis (3-methylphenyl) [1,1'-
Biphenyl] -4,4'-diamine was used as a charge transport material, dissolved together with 6 parts of a polycarbonate Z resin in 40 parts of monochlorobenzene, and the resulting solution was applied on the charge generation layer by a dip coating apparatus. 6 at 115 ° C
By heating and drying for 0 minute to form a charge transport layer having a thickness of 18 μm, an OPC drum was produced.

The obtained OPC drum was used in a copying machine for A4 size paper, and the use was completed at the end of 4000 copies. At this time, the charge transport layer was worn to a thickness of 16 μm and the chargeability was deteriorated, but there was no other damage. This used OPC drum is placed in DMSO 90
Of SUS304 stainless steel containing a mixed solution containing 10 parts by weight of nitric acid and 10 parts of nitric acid. The container is placed in an ultrasonic cleaner (DTH-8210, manufactured by Yamato Scientific Co., Ltd.) and heated to 60 ° C. While performing ultrasonic cleaning, the photosensitive layer and the undercoat layer were removed. Next, the OPC drum is further subjected to ultrasonic cleaning using ion-exchanged water, and after drying, it is confirmed that the photosensitive layer and the undercoat layer do not remain on the surface of the substrate, and that there is no flaw or foreign matter adhesion. After confirmation, an undercoat layer and a photosensitive layer were formed again in the same manner as described above. The OPC drum reproduced in this way could be used like a new product.

Example 2 Tributoxy zirconium acetylacetonate (ZC
540, manufactured by Matsumoto Kosho Co., Ltd.)
Parts, γ-aminopropyltriethoxysilane (A-11
00, manufactured by Nippon Unicar) 10 parts and n-butanol 1
In a solution obtained by mixing 30 parts, 30 parts of ultrafine titanium oxide (STT30D, manufactured by Titanium Industry Co., Ltd.) having a particle size of 0.09 μm was dispersed by a sand mill. On the other hand, 30mmφ × 253m
m SUS304 stainless steel pipe was prepared as a substrate, and the surface thereof was ground with a grindstone to obtain a surface roughness of Rm
A rough surface with ax = 1.8 μm and Ra = 0.22 μm was formed. The above-mentioned dispersion liquid is applied to the finished surface using a ring coating machine, and heated at 140 ° C. for 10 minutes, and a zirconium compound and a silane compound react with each other to form a 2.0 μm-thick inorganic cured film. Was formed. Next, a polyvinyl butyral resin (Eslec BM
-S, manufactured by Sekisui Chemical Co., Ltd.) and 2% chlorogallium phthalocyanine pigment (P) in a 2% n-butyl acetate solution (B) at a P: B ratio of 1: 1. Time dispersion was performed. The dispersion was further diluted with n-butyl acetate, applied on the undercoat layer, and heated at 100 ° C.
For 10 minutes to form a charge generation layer having a thickness of 0.18 μm. An OPC drum was formed thereon by forming a charge transport layer in the same manner as in Example 1.

The obtained OPC drum was used in an A4 laser printer, and the use was completed when 4000 sheets were output. On the other hand, 90 parts of DMSO used in Example 1 and nitric acid 1
After filtering 0 parts of the mixed solution to remove the coating film residue in the mixed solution, DMSO was purified by distillation using a vacuum distillation apparatus. The purity of DMSO after distillation was determined by high performance liquid chromatography (HP1050, Hewlett Packard).
Manufactured by Excelpak SIL-C18 / 5
It was 99.6% when measured using B). The used OPC drum is immersed in the SUS304 stainless steel cylindrical container containing the distilled DMSO, put in an ultrasonic cleaner together with the container, and subjected to ultrasonic cleaning while heating to 60 ° C. The charge transport layer and the charge generation layer were removed. The undercoat layer was hardened and remained without being affected. Next, after performing ultrasonic cleaning using ion-exchanged water and drying, it is confirmed that the charge transport layer or the charge generation layer does not remain on the substrate surface, and that there is no flaw or adhesion of foreign matter, and the above-described method is repeated. By forming a charge generation layer and a charge transport layer on this undercoating layer in the same manner as
A regenerated OPC drum was made. The OPC drum reproduced in this way could be used like a new product.

Comparative Example 1 A new OPC drum was manufactured in the same manner as in Example 1.
This was subjected to a durability test using a copying machine, and this was used as an used OPC drum. The used OPC drum was immersed in a SUS304 stainless steel cylindrical container containing a mixed solution of 50 parts of methyl alcohol and 50 parts of methylene chloride, and then immersed in hot water at 80 ° C. for 10 minutes. The photosensitive layer and the undercoat layer were removed by immersion in cold water of 10 ° C. for 10 minutes. Observation of the surface of the substrate confirmed that a part of the undercoat layer remained in a part. The undercoat layer and the photosensitive layer were formed thereon again, and the OPC drum was reproduced. When the reproduced OPC drum was mounted on the above copying machine and copied, the thickness of the undercoat layer and the photosensitive layer became nonuniform, and density unevenness occurred in the copied image. The OPC drum reproduced in this way is inconvenient and inconvenient for reuse.

[0020]

According to the method of reproducing an OPC drum according to the present invention, as described above, a used OPC drum that has become unusable due to abrasion or deterioration of a photosensitive layer due to copying can damage a conductive substrate. It can be used many times by regenerating without waste, which is extremely beneficial in reducing waste, conserving resources and saving costs. Also, OPC
By repeatedly distilling and purifying the solvent such as DMSO used for the regeneration of the drum and using it repeatedly, it is possible to reduce the amount of the solvent used such as DMSO and to improve the safety and the effect on the environment.

Claims (5)

[Claims] 1. A solvent containing an aprotic polar solvent having a dielectric constant of 20 or more and a dipole moment of 3 or more from a used organic photoreceptor drum having a photosensitive layer on a conductive substrate. A method for regenerating an organic photoreceptor drum, comprising removing a photosensitive layer by washing with purified water, and then forming a new photosensitive layer again after washing with purified water. 2. The method according to claim 1, wherein the organic photoreceptor drum is provided with an undercoat layer made of an organometallic compound on a surface of a conductive substrate. . 3. The method according to claim 1, wherein the polar aprotic solvent is dimethyl sulfoxide. 4. The method according to claim 1, wherein the solvent containing a polar aprotic solvent is a mixture of dimethyl sulfoxide and an inorganic acid. 5. The organic photoreceptor drum according to claim 1, wherein the solvent used for regenerating the organic photoreceptor drum is purified and then reused. Playback method.