JP2002278119A - Electrophotographic sensitive body capable of conductive base reproduction processing and conductive base reproducing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrophotographic sensitive body which can easily have its conductive base reproduced after deteriorating in function or becoming a defective and a method for reproducing the conductive base. SOLUTION: The electrophotographic sensitive body which can have its conductive base reproduced has a photosensitive layer laminated on the conductive base across an intermediate layer formed principally of inorganic pigment and thermosetting resin and is characterized by that the intermediate layer contains an ammonium salt compound of a block copolymer having an acid radical. The conductive base reproducing method is characterized by that the intermediate layer and photosensitive layer are removed from the conductive base by applying a mechanical external force (impulse force, frictional force, etc., of water) to the electrophotographic sensitive body.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photosensitive member capable of regenerating a conductive support and a method for regenerating a conductive support from an electrophotographic photosensitive member capable of regenerating a conductive support. .

[0002]

2. Description of the Related Art Conventionally, as a photoconductive material for an electrophotographic photoreceptor, an organic photoconductive material having superiority in sensitivity, thermal stability, toxicity, etc. with respect to inorganic materials such as Se, CdS, ZnO and the like has been used. The development of electrophotographic photoreceptors using the electrophotographic photoreceptors has been actively carried out, and many copying machines and printers have been equipped with electrophotographic photoreceptors using an organic photoconductive material. In recent years, with the rapid progress of digitalization, shipments of SOHO and printers for personal use have rapidly increased, and the photoconductor itself that has reached the end of its life and the waste of cartridges containing the photoconductor have been accompanying this. Is a major problem. Manufacturers are working to recycle cartridges for these wastes from the perspective of reducing wastes.However, in practice, many parts are reused, and for photoconductors, bare tubes are reused very little. At present, most of them are limited to reuse as a conductive material. Recently, a cylindrical aluminum substrate has been used on an as-drawn surface to reduce the cost of the substrate.
There is also a direction in which the substrate is not reused. However, this is, of course, not desirable from the viewpoint of environmental protection and effective recycling of used resources. Under these circumstances, there has been a movement to reuse a used photoreceptor substrate as a photoreceptor substrate, not as aluminum.

As a method for reprocessing an electrophotographic photoreceptor, Japanese Patent Application Laid-Open No. 4-337774 discloses a method in which fine-particle ice is strongly jetted to peel off a coating film and then to wash and dry. JP-A-5-181289 discloses a method of removing an organic coating film with a treatment solution containing at least a carboxylic acid, a phenol compound and a ketone compound.
Japanese Patent Application Laid-Open No. H11-295908 discloses a method in which a polishing wheel having elasticity is brought into rotational contact with a photoreceptor to polish and remove a photosensitive layer. JP-A-11-24288
The publication discloses that the dielectric constant is 20 or more and the dipole moment is 3
A method for removing a photosensitive layer using a solvent containing the above aprotic polar solvent is disclosed. JP-A-8-14
No. 6623 discloses a method of oxidatively decomposing an organic solvent-insoluble undercoat layer with an oxidizing acid and removing the layer with a mechanical external force.

However, in the polishing method, polishing scratches are easily generated on the surface of the substrate, and when an image is output from a reproduction photoreceptor,
It is easy to generate abnormal images corresponding to polishing scratches. In addition, the method of processing with organic chemicals requires a large number of steps and equipment in the cleaning process after the removal of the coating film, and when the cleaning process is incomplete, when an image is output on the reproduced photoreceptor, abnormal When an image is generated or an acid remains, the chargeability is reduced. Therefore, a conventional method for regenerating a conductive support and an electrophotographic photoreceptor suitable for regenerating a conductive support have not been obtained by conventional methods.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide an electrophotographic photoreceptor having a reduced function or an electrophotographic photoreceptor which has become defective, in the case of regenerating a conductive support, which can be easily regenerated. A photographic photoreceptor is provided. Still another object of the present invention is to provide a method for easily regenerating a conductive support from an electrophotographic photosensitive member capable of regenerating a conductive support.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, have found that an inorganic pigment formed on a conductive support and a thermosetting resin mainly composed of a thermosetting resin. By including a specific compound in the layer, the present inventors have found that the intermediate layer can be easily removed from the conductive support without damaging the conductive support and without using a special solvent or method. Was completed.

That is, according to the present invention, there is provided an electrophotographic photosensitive member in which a photosensitive layer is laminated on a conductive support via an intermediate layer containing at least an inorganic pigment and a thermosetting resin as main components. An electrophotographic photosensitive member capable of regenerating a conductive support, characterized in that the intermediate layer contains an ammonium salt compound of a block copolymer having an acid group. According to the present invention, the content of the ammonium salt compound of the acid-containing block copolymer is 0.3 to 10 parts by weight with respect to 100 parts by weight of the inorganic pigment. An electrophotographic photoreceptor capable of regenerating a support is provided. Further, according to the present invention, the acid value of the ammonium salt compound of the block copolymer having an acid group is from 20 to 200 mgKOH / g, and the amine value is 2 mgKOH / g.
An electrophotographic photosensitive member capable of regenerating the conductive support according to any one of the above, wherein the amount is from 0 to 200 mgKOH / g. Further, according to the present invention, the photosensitive layer is laminated on the conductive support via an intermediate layer containing at least an inorganic pigment and a thermosetting resin as main components and an ammonium salt compound of a block copolymer having an acid group. A method of regenerating a conductive support, which comprises applying a mechanical external force to the electrophotographic photosensitive member to remove the intermediate layer and the photosensitive layer from the conductive support. Furthermore, according to the present invention, there is provided the method for regenerating a conductive support, wherein the mechanical external force is a water collision force or a water friction force.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail.
As described above, the electrophotographic photoreceptor of the present invention comprises, on the conductive support, an intermediate layer containing an inorganic pigment and a thermosetting resin as main components, and further containing an ammonium salt compound of a block copolymer having an acid group. Wherein the photosensitive layer is laminated via the substrate. The ammonium salt compound of the block copolymer having an acid group used in the present invention is an ammonium salt of a polymer of a type in which at least the polymer A and the polymer B are linked, and the polymer A and the polymer B
Examples include polystyrene, polyvinyl acetate, polyvinyl alcohol, polyacrylic acid, polymethacrylic acid, polyethylene glycol, polyethylene terephthalate, polyoxyethylene, polymethyl vinyl ketone, maleic anhydride resin, chloroprene resin, polyacrylonitrile, polyester, and polybutylene. Terephthalate and the like are mentioned, and the block copolymer is an ammonium salt having an acid group. As the ammonium salt compounds of these block copolymers having an acid group, commercially available products such as BYK-180 and BYK-140 manufactured by BYK-Chemie are available.
And BYK-181, and others having a structure similar thereto.

The reason why it is preferable to include these compounds in the intermediate layer in the present invention is considered as follows. In general, thermosetting resins are those obtained by thermally condensing a compound having an acid group and a base.The ammonium salt compound of the block copolymer having an acid group included in the present invention has an acid group moiety. Adsorbs to inorganic pigments and contributes to deagglomeration and dispersion stabilization, and the ammonium salt part interacts with the acid group part of the thermosetting resin, resulting in strong adhesion of the thermosetting resin to the conductive support It is considered to have a function of alleviating this.

The acid value of the ammonium salt compound of the block copolymer having an acid group used in the present invention is from 20 to 200 mg.
KOH / g is preferable, and the amine value is 20 to 200 m.
gKOH / g is preferred. However, the acid value of the ammonium salt compound of the block copolymer having an acid group is 20 mg KO.
When it is less than H / g, or when the amine value is less than 20 mgKOH / g, the effect on dispersion stability or adhesion relaxation of inorganic pigments becomes small. The acid value of the ammonium salt compound of the block copolymer having an acid group is 200 mgK.
OH / g or amine value is 200 mgK
If it exceeds OH / g, the adhesiveness will be remarkably reduced, causing problems in practical use, and also the electrostatic stability will cause a decrease in chargeability and an increase in residual potential.

The content of the ammonium salt compound of the block copolymer having an acid group is preferably 0.3 to 10 parts by weight with respect to 100 parts by weight of the inorganic pigment, and the reason is the same as the above.

Hereinafter, the present invention will be described with reference to the configuration of an electrophotographic photosensitive member. FIG. 1 is a cross-sectional view illustrating a configuration example of the electrophotographic photoreceptor of the present invention. On an electroconductive support 11, at least an inorganic pigment, a thermosetting resin, and an ammonium salt compound of a block copolymer having an acid group are prepared. Intermediate layer 13 containing
And the photosensitive layer 15 are laminated. FIG. 2 is a cross-sectional view illustrating another configuration example of the electrophotographic photoreceptor of the present invention.
On the conductive support 11, at least an intermediate layer 13 containing an inorganic pigment, a thermosetting resin, and an ammonium salt compound of a block copolymer having an acid group, and a charge generation layer 17 and a charge transport layer 19 laminated thereon. The configuration is as follows. FIG. 3 is a cross-sectional view showing still another configuration example of the present invention, in which a protective layer 21 is provided on a charge transport layer 19.

The conductive support 11 has a volume resistance of 10
Those exhibiting conductivity of ¹⁰ Ωcm or less, for example, aluminum, nickel, chromium, nichrome, copper, gold, silver, platinum and other metals, tin oxide, metal oxides such as indium oxide, by evaporation or sputtering, Film or cylindrical plastic or paper coated or plate made of nickel, stainless steel, etc., and extruded, drawn, etc., made into a tube, then surface treated such as cutting, super finishing, polishing, etc. And so on. JIS3003, JIS for aluminum pipe
Aluminum alloys such as 5000 series and JIS 6000 series are formed into a tube by a general method such as the EI method, the ED method, the DI method, and the II method. Those that have undergone processing or the like can be used. In addition, Japanese Unexamined Patent Publication No.
An endless nickel belt and an endless stainless belt disclosed in JP-A-2-36016 are also used as the conductive support 11.
Can be used as

In addition to the above, a support obtained by dispersing a conductive powder on a suitable binder resin on the above support and applying the same can also be used as the conductive support 11 of the present invention. Examples of the conductive powder include carbon black, acetylene black, metal powders such as aluminum, nickel, iron, nichrome, copper, zinc, and silver, and metal oxides such as conductive titanium oxide, conductive tin oxide, and ITO. And the like.

The binder resin used simultaneously includes polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate. Copolymer, polyvinyl acetate, polyvinylidene chloride, polyarylate resin, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal,
Polyvinyl toluene, poly-N-vinyl carbazole,
Thermoplastic, thermosetting or photo-curable resins such as acrylic resin, silicone resin, epoxy resin, melamine resin, urethane resin, phenol resin, and alkyd resin.

Such a conductive layer can be provided by dispersing the conductive powder and the binder resin in an appropriate solvent, for example, tetrahydrofuran, dichloromethane, 2-butanone, toluene, or the like, and applying the dispersion. .

Further, heat shrinkage of a material such as polyvinyl chloride, polypropylene, polyester, polystyrene, polyvinylidene chloride, polyethylene, chlorinated rubber, Teflon (registered trademark) or the like containing the conductive powder on a suitable cylindrical substrate. Also those that have a conductive layer provided by a tube,
It can be favorably used as the conductive support 11 of the present invention.

The intermediate layer 13 of the photoreceptor of the present invention comprises an inorganic pigment,
It contains a thermosetting resin as a main component, but contains an ammonium salt compound of a block copolymer having an acid group. As the thermosetting resin, polyurethane, melamine resin, phenol resin, alkyd-melamine resin, epoxy resin,
An acrylic resin, a benzoguanamine resin, and the like can be given.

As the inorganic pigment, titanium oxide, zirconium oxide, alumina, titanium nitride, tin oxide, zinc oxide, magnesium oxide, silica, and a surface-treated product thereof can be used. preferable. Preferred reasons include a high refractive index for light and a high ability to prevent moiré, and the fact that the residual electric charge and the like are small in terms of electrical characteristics and are preferable. In particular, from the viewpoint of electrostatic characteristics, it is preferable to use titanium oxide having a purity of 98% or more. The weight ratio between titanium oxide and resin is as follows: titanium oxide / resin = 3 /
It is preferably 1 to 8/1. When the ratio is less than 3/1, the carrier transporting ability of the intermediate layer is reduced to cause a residual potential,
The light responsiveness decreases. If it is larger than 8/1, the voids in the intermediate layer increase, and when the photosensitive layer is coated on the intermediate layer, bubbles are generated. These intermediate layers 13 can be formed using a suitable solvent and a coating method as in the case of the photosensitive layer described later. The thickness of the intermediate layer 13 is suitably 10 μm or less.

The charge generating layer 17 of the photoreceptor of the present invention contains at least a charge generating substance and, if necessary, a binder resin. As the binder resin used for the charge generation layer 17 as necessary, polyamide, polyurethane, epoxy resin,
Polyketone, polycarbonate, silicone resin, acrylic resin, polyvinyl butyral, polyvinyl formal, polyvinyl ketone, polystyrene, polysulfone,
Poly-N-vinyl carbazole, polyacrylamide,
Examples include polyvinyl benzal, polyester, phenoxy resin, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyphenylene oxide, polyamide, polyvinyl pyridine, cellulose resin, casein, polyvinyl alcohol, polyvinyl pyrrolidone, and the like. The amount of the binder resin is 0 to 50 with respect to 100 parts by weight of the charge generating substance.
0 parts by weight, preferably 10 to 300 parts by weight, is suitable.

Examples of the charge generating substance include phthalocyanine pigments such as metal phthalocyanine and non-metal phthalocyanine, azulhenium salt pigments, methine squaric acid pigments, perylene pigments, anthraquinone or polycyclic quinone pigments, quinone imine pigments, diphenylmethane, Use of azo pigments such as triphenylmethane pigments, benzoquinone and naphthoquinone pigments, cyanine and azomethine pigments, indigoid pigments, bisbenzimidazole pigments, monoazo pigments, bisazo pigments, asymmetric disazo pigments, trisazo pigments, and tetraazo pigments Can be. Specific examples of azo pigments include azo pigments having a carbazole skeleton (described in JP-A-53-95033), azo pigments having a triphenylamine skeleton (described in JP-A-53-13247), and stills Azo pigments having a stilbene skeleton (described in JP-A-53-138229), azo pigments having a dibenzothiophene skeleton (described in JP-A-54-21728), and azo pigments having a fluorenone skeleton (described in JP-A-54-21728) No. 22834), an azo pigment having an oxadiazole skeleton (described in JP-A-54-12742), an azo pigment having a bisstilbene skeleton (described in JP-A-54-17733), Azo pigment having styryl oxadiazole skeleton (described in JP-A-54-2129), distyrylcarbazole bone Azo pigments having a (JP-5
4-17734) and the like.

The charge generation layer 17 comprises a ball mill containing at least a charge generation material and, if necessary, a binder resin in a suitable solvent.
An attritor, a sand mill, a coating liquid is prepared by dispersing using an ultrasonic wave or the like, applied on the intermediate layer 13, and formed by drying.The solvent used here is, for example, isopropanol, acetone, Methyl ethyl ketone,
Cyclohexanone, tetrahydrofuran, dioxane,
Examples include dioxolan, ethyl cellosolve, ethyl acetate, methyl acetate, dichloromethane, dichloroethane, monochlorobenzene, cyclohexane, toluene, xylene, ligroin and the like. Coating methods include dip coating, spray coating, beat coating, nozzle coating,
Methods such as spinner coating and ring coating can be used. The thickness of the charge generation layer 17 is suitably about 0.01 to 5 μm, and preferably 0.1 to 2 μm.

The charge transport layer 19 of the photoreceptor of the present invention is a layer containing a charge transport material as a main component. The charge transport material and the binder resin are mixed with a suitable solvent such as tetrahydrofuran, dioxane, dioxolan, anisole, toluene, and the like. It can be formed by dissolving or dispersing in monochlorobenzene, dichloroethane, methylene chloride, cyclohexanone, or the like, applying the solution or dispersion, and drying.

The charge transporting material includes a hole transporting material and an electron transporting material. Examples of the electron transporting material include chloranil, bromoanil, tetracyanoethylene, tetracyanoquinodimethane, 2,4,7-trinitron. -9-
Fluorenone, 2,4,5,7-tetranitroxanthone, 2,4,8-trinitrothioxanthone, 2,6
8-trinitro-4H-indeno [1,2-b] thiophen-4-one, 1,3,7-trinitrodibenzothiophene-5,5-dioxide, 3,5-dimethyl-
Known electron-accepting substances such as 3 ', 5'-di-tert-butyl-4,4'-diphenoquinone are exemplified. These electron transport materials can be used alone or as a mixture of two or more.

Examples of the hole transport material include poly-N-vinylcarbazole and its derivatives, poly-γ-carbazolylethylglutamate and its derivatives, pyrene-formaldehyde condensate and its derivatives, polyvinylpyrene, polyvinylphenanthrene, polysilane, Oxazole derivatives, oxadiazole derivatives, imidazole derivatives, monoarylamine derivatives, diarylamine derivatives, triarylamine derivatives, stilbene derivatives,
α-phenylstilbene derivative, benzidine derivative, diarylmethane derivative, triarylmethane derivative, 9
-Styryl anthracene derivative, pyrazoline derivative, divinylbenzene derivative, hydrazone derivative, indene derivative, butadiene derivative, pyrene derivative, bisstilbene derivative, enamine derivative, thiazole derivative, triazole derivative, phenazine derivative, acridine derivative,
Examples thereof include a benzofuran derivative, a benzimidazole derivative, and a thiophene derivative. These hole transport substances can be used alone or as a mixture of two or more kinds.

The binder resin used for the charge transport layer 19 includes polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride,
Vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyvinylidene chloride, polyarylate, phenoxy resin,
Polycarbonate (bisphenol A type, bisphenol-
Cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly-N-vinyl carbazole, acrylic resin, silicone resin, epoxy resin, melamine resin, urethane resin, phenol resin, alkyd resin, Thermoplastic or thermosetting resins such as various polycarbonate copolymers described in JP-A-5-158250 and JP-A-6-51544.

As the binder resin, a polymer charge transport material having a function as a binder resin and a function as a charge transport material can also be used. Examples of such a polymer charge transport material include (a) a polymer having a carbazole ring in the main chain and / or side chain, for example, poly-N-
Vinyl carbazole, JP-A-50-82056,
JP-A-54-9632, JP-A-54-11737
And the compounds described in JP-A-4-183719. (B) Polymers having a hydrazone structure in the main chain and / or side chain, for example, JP-A-57-7
Compounds described in JP-A-8402 and JP-A-3-50555 can be exemplified. (C) a polysilylene polymer,
For example, JP-A-63-285552,
Compounds described in JP-A-194497 and JP-A-5-70595 can be exemplified. (D) a polymer having a tertiary amine structure in the main chain and / or side chain, for example, N,
N-bis (4-methylphenyl) -4-aminopolystyrene, JP-A-1-13061, JP-A-1-190
No. 49, Japanese Patent Laid-Open No. 1-1728, Japanese Patent Laid-Open No. 1-1
Compounds described in JP-A-05260, JP-A-2-167335, JP-A-5-66598, and JP-A-5-40350 can be exemplified. The amount of the binder resin used is suitably from 0 to 150 parts by weight based on 100 parts by weight of the charge transport material.

The charge transport layer 19 may include
Plasticizers, leveling agents, antioxidants and the like can also be added. Examples of such a plasticizer include polymers and copolymers of halogenated paraffin, dimethylnaphthalene, dibutyl phthalate, dioctyl phthalate, tricresyl phosphate, polyester, and the like. As the leveling agent, silicone oils such as dimethyl silicone oil and methylphenyl silicone oil, and polymers or oligomers having a perfluoroalkyl group in a side chain are used.
About 0 to 1 part by weight is suitable for 100 parts by weight of the binder resin. As antioxidants, hindered phenol compounds, sulfur compounds, phosphorus compounds, hindered amine compounds, pyridine derivatives, piperidine derivatives,
An antioxidant such as a morpholine derivative can be used, and its amount is suitably about 0 to 5 parts by weight based on 100 parts by weight of the binder resin. The thickness of the charge transport layer thus formed is suitably about 5 to 50 μm.

The photosensitive layer 15 of the single-layer type photosensitive member of the present invention comprises a charge generating substance, a dispersant, a charge transporting substance, and a binder resin. Charge generation materials, dispersants, and charge transport materials include:
The above materials can be used. In order to form such a single-layer photosensitive layer, a charge generation material, a charge transport material,
The dispersant and the binder resin are dissolved or dispersed in a suitable solvent, for example, a solvent such as tetrahydrofuran, cyclohexanone, dioxane, dichloroethane, butanone by a ball mill, an attritor, a sand mill, etc., diluted appropriately, coated and dried. I just need. The coating can be performed by using an immersion coating method, a spray coating method, a roll coating method, a blade coating method, or the like.

As the binder resin used for the photosensitive layer 15, the binder resin exemplified as the binder resin for the charge transport layer can be used as it is, and the binder resin exemplified as the binder resin for the charge generation layer can be used. May be used as a mixture. Further, a single-layer type photosensitive layer obtained by adding a charge transporting substance to a eutectic complex formed from a pyrylium-based dye and bisphenol A-type polycarbonate can also be formed by the same coating method as described above using an appropriate solvent. . Further, a plasticizer, a leveling agent, an antioxidant and the like can be added to the single-layer type photosensitive layer, if necessary. The thickness of the single-layer type photosensitive layer thus formed is suitably about 5 to 50 μm.

The protective layer 21 of the photoreceptor of the present invention is provided for the purpose of improving the durability of the photoreceptor. Examples of materials used for the protective layer 21 include an ABS resin, an ACS resin, an olefin-vinyl monomer copolymer, and a chlorinated polyolefin. Ether, allyl resin, phenol resin, polyacetal, polyamide, polyamideimide, polyacrylate, polyallylsulfone, polybutylene, polybutylene terephthalate, polycarbonate, polyethersulfone, polyethylene, polyethylene terephthalate, polyimide, acrylic resin, polymethylpentene, polypropylene, Examples include resins such as polyphenylene oxide, polysulfone, polystyrene, AS resin, butadiene-styrene copolymer, polyurethane, polyvinyl chloride, polyvinylidene chloride, epoxy resin, and polyester. That.

For the purpose of improving the abrasion resistance, a fluororesin such as polytetrafluoroethylene,
Silicone resin, titanium oxide, aluminum oxide,
An inorganic material such as tin oxide, zinc oxide, zirconium oxide, magnesium oxide, silica, and a surface-treated product thereof can be added, and a material further added with a charge transporting substance can be used.

As a method for forming the protective layer 21, a usual coating method can be used. The thickness of the protective layer 21 is suitably from 0.1 to 10 μm. In addition, other known materials such as aC and a-SiC formed by a vacuum thin film forming method can be used as the protective layer 21.

In the present invention, the photosensitive layer 15 and the protective layer 21
It is also possible to provide another intermediate layer (not shown) between them. The other intermediate layer generally uses a resin as a main component. Examples of these resins include polyamide, alcohol-soluble nylon resin, water-soluble butyral resin, polyvinyl butyral, and polyvinyl alcohol. As another method for forming the intermediate layer, a normal coating method can be used as described above. Incidentally, the film thickness is suitably 0.05 to 2 μm.

The method for regenerating the conductive support of the present invention is carried out by applying a mechanical external force to the intermediate layer coating film. For example,
The method can be carried out by lightly rubbing with a contact cleaning member such as a soft foam sponge (for example, Everlight Scott HR-30 manufactured by Bridgestone Corporation). In addition, as the mild mechanical external force in this case, the impact force or frictional force of water can be preferably used. In this case, the conductive support is washed with water simultaneously with the removal of the coating film, and the conductive support is used. There is an advantage that the body surface can be prevented from being damaged. The collision force of water can be obtained by water injection or the like, and the frictional force of water can be obtained by moving the conductive support in water. In the former method, the linear velocity of water impinging on the intermediate layer coating film is 0.1 to
The water injection time is set to 10 m / sec, preferably 0.5 to 5 m / sec, and the water injection time is desirably 0.5 to 5 minutes, preferably 1 to 2 minutes. In the latter method, the relative linear velocity between the surface of the interlayer coating film and water contacting the surface is 0.1 to 10 m /.
Seconds, preferably 0.5 to 5 m / sec, it is desirable to maintain the state for 0.5 to 5 minutes, preferably 1 to 2 minutes. When the intermediate layer coating film is removed by a hydraulic force such as a water collision force or a frictional force, the water temperature is preferably 40 ° C. or lower, and more preferably 10 to 30 ° C. If the water temperature is too high, the adhesion between the conductive support and the intermediate layer coating film will be high, and the removal of the coating film will be poor, and problems such as partial residual coating film will occur.

Since the surface of the conductive support thus obtained has water adhered thereto, the adhered water is dried and removed as necessary. In this drying, the surface of the conductive support can be wetted with a hydrophilic low-boiling solvent in advance to shorten the drying time. The solvent used here has a boiling point of 100, such as methanol, ethanol, isopropanol, acetone and tetrahydrofuran.
Any solvent can be used as long as it is a hydrophilic solvent having a temperature of not more than ° C.

The method for regenerating the conductive support of the present invention can be carried out even if the electrophotographic photosensitive member is provided with a protective layer. Further, the method can be carried out even when an organic solvent-insoluble binder resin is used for the photosensitive layer and the protective layer formed on the intermediate layer.

[0038]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to examples, but the present invention is not limited to these examples.

Example 1 80 parts by weight of titanium oxide (CR-EL: manufactured by Ishihara Sangyo), 24 parts by weight of alkyd resin (Beccolite M6402-50 (solid content: 50% by weight): manufactured by Dainippon Ink and Chemicals, Inc.)
Melamine resin (Super Beckamine G-821-60
(Solid content 60% by weight): manufactured by Dainippon Ink and Chemicals, Inc.
3.0 parts by weight of a block copolymer having an acid value of 90 mgKOH / g and an amine value of 95 mgKOH / g as an ammonium salt compound of a block copolymer having an acid group, and 70 parts by weight, methyl ethyl ketone and 70 parts by weight of methyl ethyl ketone. Parts of the mixture were dispersed in a ball mill for 72 hours to prepare a coating liquid for an intermediate layer. This is φ3
It was applied on an aluminum drum having a length of 0 mm and a length of 340 mm and dried at 130 ° C. for 20 minutes to form an intermediate layer having a thickness of 4.5 μm. Next, 10 parts by weight of a trisazo pigment represented by the following structural formula (I), polyvinyl butyral (BM-1:
4 parts by weight of cyclohexanone 150
Added to the resin solution dissolved in parts by weight and
Time dispersion was performed. After the dispersion, cyclohexanone 21
0 parts by weight were added and the mixture was dispersed for 3 hours to prepare a coating liquid for a charge generation layer. This was applied on the intermediate layer and dried at 130 ° C. for 10 minutes to form a 0.2 μm-thick charge generation layer. Next, 7 parts by weight of a compound represented by the following structural formula (II), 10 parts by weight of a polycarbonate resin (Iupilon Z300: manufactured by Mitsubishi Gas Chemical Company), and silicone oil (KF-50:
0.002 parts by weight of Shin-Etsu Chemical Co., Ltd.) was dissolved in 100 parts by weight of tetrahydrofuran to prepare a coating liquid for a charge transport layer. This was applied on the charge generation layer,
After drying for 0 minutes, a charge transport layer was formed so as to have an average film thickness of 25 μm to obtain an electrophotographic photosensitive member.

Embedded image

Embedded image

Example 2 A block copolymer having an acid value of 90 mgKOH / g and an amine value of 95 mgKOH / g (Diperbyk-
180: manufactured by Big Chemie Co., Ltd.), and an electrophotographic photosensitive member of Example 2 was prepared in the same manner as in Example 1 except that the addition amount was changed to 0.5 part by weight.

Example 3 As the ammonium salt compound of the block copolymer having an acid group used for the intermediate layer, a block copolymer having an acid value of 90 mgKOH / g and an amine value of 95 mgKOH / g (Diperbyk-
180: manufactured by Big Chemie Co., Ltd.), and an electrophotographic photosensitive member of Example 3 was prepared in the same manner as in Example 1 except that the addition amount was changed to 6.0 parts by weight.

Example 4 An acid value of 76 mg KOH / g and an amine value of 72 mg KOH / g were used in place of the ammonium salt compound of the block copolymer having an acid group (Diperbyk-180: manufactured by BYK Chemie) used in the coating solution for the intermediate layer. The electrophotographic photoreceptor of Example 4 was prepared in the same manner as in Example 1 except that 4.6 parts by weight of an ammonium salt compound of a block copolymer having an acid group (Diperbyk-140: manufactured by BYK-Chemie) was used. did.

Example 5 An acid value of 33 mg KOH / g and an amine value of 33 mg KOH / g were used in place of the ammonium salt compound of the block copolymer having an acid group (Diperbyk-180: manufactured by BYK Chemie) used in the coating solution for the intermediate layer. The electrophotographic photoreceptor of Example 5 was prepared in the same manner as in Example 1 except that 3.7 parts by weight of an ammonium salt compound of a block copolymer having an acid group (Diperbyk-181: manufactured by BYK-Chemie) was used. did.

Comparative Example 1 Comparative Example 1 was carried out in the same manner as in Example 1 except that an ammonium salt compound of a block copolymer having an acid group (Diperbyk-180, manufactured by BYK-Chemie) was not added to the coating solution for the intermediate layer. Was prepared.

Comparative Example 2 An unsaturated polycarboxylic acid having an acid value of 100 mg KOH / g was used in place of the ammonium salt compound of a block copolymer having an acid group (Diperbyk-180: manufactured by BYK Chemie) used in the coating solution for the intermediate layer. Acid polyester (BYK-220S:
An electrophotographic photoreceptor of Comparative Example 2 was prepared in the same manner as in Example 1 except that 4.6 parts by weight of B.C.

Comparative Example 3 In place of the ammonium salt compound (Diperbyk-180: manufactured by BYK Chemie) of the block copolymer having an acid group used in the coating solution for the intermediate layer, a high molecular weight block copolymer having an amine value of 11 mgKOH / g was used. An electrophotographic photoreceptor of Comparative Example 3 was prepared in the same manner as in Example 1 except that 8.0 parts by weight of a polymer (Diperbyk-161: manufactured by Big Chemie) was used.

Comparative Example 4 In place of the acid group-containing block copolymer (Diperbyk-180, manufactured by BYK-Chemie) used in the coating solution for the intermediate layer,
A copolymer having an acid value of 53 mgKOH / g (Dipe
An electrophotographic photoreceptor of Comparative Example 4 was prepared in the same manner as in Example 1 except that 4.6 parts by weight of Rbyk-110 (manufactured by BYK-Chemie) was used.

Examples 1 to 5 and Comparative Example 1 prepared above
The electrophotographic photoreceptors of Nos. 1 to 4 were evaluated as follows. <Removability of Coating Film> First, the obtained electrophotographic photosensitive member was set on a drum support, and rotated at a rotation speed of 5 rpm.
Next, a water jet was applied to the surface of the electrophotographic photosensitive member for 2 minutes at a relative linear velocity of 3 m / sec between the surface of the photosensitive member and water contacting the surface. Water temperature is 2
0 ° C. Thereafter, the state of detachment of the coating of the photosensitive layer (intermediate layer, charge generation layer, charge transport layer) of the photosensitive member was visually examined. Then, the evaluation was evaluated as 5 when the photosensitive layer coating film was completely removed, and 4 when the upper and lower ends of the photosensitive layer coating film could be easily removed by rubbing with a contact cleaning member. The case where the photosensitive layer coating film remains was indicated as 3, the case where about half of the photosensitive layer coating film remained, and 1 when the entire photosensitive layer coating film remained. <Electrophotographic characteristics and images> After the above-mentioned coating film removal and normal pipe cleaning work (some coating films could not be removed)
An electrophotographic photoreceptor was prepared in the same manner as in Example 1 using the conductive support described above, and the electrophotographic properties and images of the photoreceptor were evaluated as follows. Using Imagio MF200 (manufactured by Ricoh Co., Ltd.) as an electrophotographic property and applying −1680 V as a charging roller voltage,
The unexposed portion potential VD (-V) and the exposed portion potential VL (-V) were measured at the initial stage and after continuous running of 20,000 sheets. The image was evaluated using an Imagio MF200 (manufactured by Ricoh Co., Ltd.) based on the presence or absence of an abnormal image in a halftone image having an image density of 0.7 using a Macbeth densitometer.

Table 1 shows the evaluation results of the coating film removability, electrophotographic characteristics and images.

[Table 1] The electrophotographic photosensitive members of Examples 1 to 5 were replaced with Imagio MF2.
A running evaluation of 60,000 sheets was continuously performed in 00 (manufactured by Ricoh Co., Ltd.), and it was confirmed that there was no problem such as peeling of the coating film, and that there was no problem in practical coating film adhesion.

Comparative Example 5 First, an electrophotographic photosensitive member was prepared in the same manner as in Example 1.
Next, as a coating film removing operation on the electrophotographic photosensitive member, DMS was performed in the same manner as in the method described in JP-A-11-24288.
SU containing a mixed solution of 90 parts by weight of O and 10 parts by weight of nitric acid
S304 Dipped in a stainless steel cylindrical container, put the entire container in an ultrasonic cleaner (DTH-8210, manufactured by Yamato Scientific Co., Ltd.), perform ultrasonic cleaning while heating to 60 ° C, and remove the coating film. The evaluation was performed in the same manner as in Example 1 except that the evaluation was performed.

Comparative Example 6 First, an electrophotographic photosensitive member was prepared in the same manner as in Example 1.
Next, in order to remove the coating film from the electrophotographic photoreceptor, it was first immersed in dichloromethane in the same manner as in the method described in JP-A-08-146623, and this was washed with a contact cleaning member Everlight Scott HR-30 manufactured by Bridgestone Corporation. Rub for 1 minute to remove the charge transport coating and the charge generating coating.
After immersing in nitric acid at 20 ° C., washed with running water at 20 ° C. for 30 seconds, air-dried, immersed in dichloromethane at 23 ° C. for 1 second, and then the coating film was removed by a water shower. Was evaluated.

Table 2 shows the evaluation results.

[Table 2]

[0053]

According to the present invention, there is provided an electrophotographic photosensitive member in which a photosensitive layer is laminated on a conductive support via an intermediate layer containing at least an inorganic pigment and a thermosetting resin as main components. By containing an ammonium salt compound of a block copolymer having an acid group in the layer, an organic solvent-insoluble intermediate layer having adhesion which is practically satisfactory, and having a low cost and a small number of steps can be easily formed. The electroconductive photoreceptor can regenerate the conductive support, and the electrophotographic photoreceptor made by reusing the regenerated electroconductive support has no problem in terms of both electrostatic characteristics and image. And an electrophotographic photoreceptor free of the problem. Further, according to the present invention, it is possible to provide a method for regenerating a conductive support from the electrophotographic photoreceptor very easily.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a configuration example of an electrophotographic photosensitive member according to the present invention.

FIG. 2 is a schematic cross-sectional view of another configuration example of the electrophotographic photosensitive member of the present invention.

FIG. 3 is a schematic cross-sectional view of another configuration example of the electrophotographic photosensitive member of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 11 conductive support 13 intermediate layer 15 photosensitive layer 17 charge generation layer 19 charge transport layer 21 protective layer

Claims (5)

[Claims] 1. An electrophotographic photoreceptor comprising a photosensitive layer laminated on a conductive support via an intermediate layer containing at least an inorganic pigment and a thermosetting resin as main components, wherein an acid group is contained in the intermediate layer. An electrophotographic photoreceptor capable of regenerating a conductive support, comprising an ammonium salt compound of a block copolymer having: 2. The conductive material according to claim 1, wherein the content of the ammonium salt compound of the block copolymer having an acid group is 0.3 to 10 parts by weight based on 100 parts by weight of the inorganic pigment. Electrophotographic photoreceptor that can be recycled. 3. The acid value of the ammonium salt compound of the block copolymer containing an acid group is 20 to 200 mg KO.
H / g and an amine value of 20 to 200 mg KOH
The electrophotographic photoreceptor of claim 1 or 2, wherein the electroconductive support can be regenerated. 4. A photosensitive layer is laminated on a conductive support via an intermediate layer containing at least an inorganic pigment and a thermosetting resin as main components and an ammonium salt compound of a block copolymer having an acid group. A method for regenerating a conductive support, comprising applying a mechanical external force to an electrophotographic photoreceptor and removing the intermediate layer and the photosensitive layer from the conductive support. 5. The method according to claim 4, wherein the mechanical external force is a water collision force or a water friction force.