JP3230235B2 - Electrophotographic photoreceptor regenerating method, reprocessing layer paint, and regenerated electrophotographic photoreceptor - 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 of reproducing an electrophotographic photosensitive member used in an electrophotographic recording method such as a copying machine or a printer, a paint for a reproduction-processed layer, and a reproduced electrophotographic photosensitive member.

[0002]

2. Description of the Related Art In recent years, organic photoconductive materials have been widely used as electrophotographic photoreceptors because of their advantages such as wide selection of materials and high productivity. Typically,
In laser printers and copiers that use the electrophotographic recording method, the photosensitive member is a toner, a charging brush, a developing roller,
It is supplied in the form of a cartridge packaged with a cleaning blade and the like. When the remaining amount of toner becomes small during use of a printer or a copying machine, the cartridge is replaced with a new one. Used cartridges are collected by manufacturers and disassembled into individual components.
Reusable members are being reused.

The collected electrophotographic photoreceptor can be reused as long as there is no abrasion or scratch, but actually, the abrasion or scratch is found in the photosensitive layer, and the photoreceptor is reused without reprocessing. Can not. In particular, in the case of a photoreceptor using an organic material as described above, abrasion is remarkable and reproduction processing is difficult.

On the other hand, the surface layer of the electrophotographic photoreceptor is directly applied with an electrical or mechanical external force such as corona charging, toner development, transfer to paper or cleaning treatment. Therefore, several methods for increasing the durability of the photoconductor have been proposed.

As a method for increasing the durability of the photosensitive member, there is a method of increasing the Tg (glass transition temperature) of a binder resin for binding the photosensitive material such as a charge generating material and a charge transport material. Further, for the purpose of improving mechanical durability, a technique using a heat or photocurable resin as a protective layer on the surface of a photoreceptor (for example, Japanese Patent Application Laid-Open No. 8-160640, hereinafter referred to as Conventional Technique 1) is disclosed. ing. According to Conventional Technique 1, conductive metal oxide fine particles are dispersed in a resin obtained by polymerizing photocurable acrylic monomers and oligomers, and by using a protective layer containing a photopolymerization initiator,
It states that it can provide an electrophotographic photoreceptor with excellent wear resistance and environmental resistance.

However, even if a photoreceptor is manufactured by using the above-described method for increasing durability, abrasion of the photosensitive layer is inevitable, and particularly in contact development, the surface layer is greatly depleted. Therefore, in order to reuse the photoconductor a plurality of times, a regenerating process is required. In this case, in a conventional photoconductor regenerating process, a method of incinerating an organic material of the photoconductor at a high temperature and reusing only a photoconductor substrate such as aluminum is widely used.

[0007]

However, in the above-mentioned method of reusing only the photoreceptor substrate, after the organic substance of the photoreceptor is incinerated, the photoreceptor is processed in the same process as a new photoreceptor manufacturing process. In many cases, the substrate needs to be manufactured, and the substrate needs to be regenerated in many cases. for that reason,
Reproduction costs increase, and the collected photoconductors are often disposed of as industrial waste.

[0008] In addition, environmental issues such as the generation of dioxins due to organic incineration in recent years, and the need for recycling of products and materials due to an increase in the amount of waste, and the like, demand for reuse of electrophotographic photoreceptors is great. .

SUMMARY OF THE INVENTION An object of the present invention is to solve such a conventional problem, and an object of the present invention is to reproduce a used electrophotographic photosensitive member or a damaged electrophotographic photosensitive member in a usable state. It is to provide a reproducing method to perform.

[0010]

The method for regenerating an electrophotographic photoreceptor of the present invention is a method for regenerating an electrophotographic photoreceptor which has been used or has a flaw, and comprises a polymerizable unsaturated group represented by the following formula (1). And a group represented by the following formula (2)

Embedded image (Wherein X is selected from -NH-, -O- and -S-,
Y is selected from an oxygen atom and a sulfur atom. However, when X is -O-, Y is a sulfur atom. 1) selected from
An organic compound having at least one species, silica particles bonded to the organic compound via a silyloxy group, and a composition mainly containing a photopolymerization initiator, applied to the photoreceptor as a reprocessing layer paint, The present invention is characterized in that a damaged part, a defective part or a worn part is repaired to produce a reusable electrophotographic photoreceptor (claim 1).

Examples of the polymerizable unsaturated group include an acryloxy group, a methacryloxy group, a vinyl group, a propenyl group, a butadienyl group, a styryl group, an ethynyl group, a cinnamoyl group, a maleate group and an acrylamide group. Particularly, an acryloxy group is preferable.

Examples of the group represented by the general formula (1) include, for example, groups represented by the following formulas.

Embedded image

Further, examples of the organic compound having a group represented by the general formula (1) include a compound represented by the following formula.

Embedded image

Here, X ¹ is an alkoxyl group, a carboxylate group, a halogen atom, an amino group, an oxime group or a hydrogen atom, and R ² is a hydrogen atom or a carbon atom having 1 to 8 carbon atoms.
A non-hydrolyzable organic group composed of carbon, oxygen and hydrogen atoms, for example, an alkyl group, an aryl group, an aralkyl group and the like.

Examples of the alkoxyl group represented by X ¹ include methoxy, ethoxy, isopropoxy, butoxy, phenoxy and octyloxy groups; examples of the carboxylate group include an acetoxy group; examples of the halogen atom include iodine, chlorine, bromine and fluorine. As the amino group, for example, a monoalkylamino group such as amino and methylamino;
Dialkylamino groups such as dimethylamino and diethylamino; and oxime groups include methylene oxime and dimethylmethylene oxime groups. M is 1, 2 or 3. Among these, an alkoxyl group is particularly desirable.

The alkyl group for R ² includes, for example, methyl, ethyl, propyl, butyl, and octyl groups; and the aryl group includes, for example, phenyl, tolyl, xylyl, p-
A methoxyphenyl group; an aralkyl group such as benzyl and phenylethyl; a non-hydrolyzable organic group composed of carbon, oxygen and hydrogen atoms such as 2-
Examples include methoxyethyl, 2-ethoxyethyl, and 2-butoxyethyl groups.

Preferred examples of the hydrolyzable silyl group constituted by the combination of X ¹ , R ² and m include trimethoxysilyl, triethoxysilyl, triisopropoxysilyl, methyldimethoxysilyl, and dimethyldimethoxysilyl. Examples thereof include a silyl group.

R ³ is selected from divalent organic groups having 1 to 12 carbon atoms and having an aliphatic or aromatic structure, and may have a chain, branched or cyclic structure. Examples of such a structural unit include, for example, a methylene, ethylene, propylene, methylethylene, butylene, methylpropylene, cyclohexylene, phenylene, 2-methylphenylene, 3-methylphenylene, octamethylene, biphenylene, dodecamethylene group and the like. it can. Of these, methylene, propylene, cyclohexylene, phenylene and the like are particularly preferred.

R ⁴ is a divalent organic group having an aliphatic or aromatic structure, and may have a linear, branched or cyclic structure. As such a structural unit, for example, divalent having a skeleton of a chain structure such as methylene, ethylene, propylene, tetramethylene, hexamethylene, 2,2,4-trimethylhexamethylene, 1- (methylcarboxyl) -pentamethylene and the like. Organic group, isophorone, cyclohexylmethane, methylenebis (4-cyclohexane), hydrogenated genylmethane, hydrogenated xylene,
Select from divalent organic groups having an alicyclic skeleton such as hydrogenated toluene and divalent organic groups having an aromatic skeleton such as benzene, toluene, xylene, paraphenylene, diphenylmethane, diphenylpropane, and naphthalene. be able to.

X is selected from -NH-, -O- and -S-, preferably -S-, and Y is an oxygen atom or a sulfur atom, preferably an oxygen atom. (However,
When X is -O-, Y is a sulfur atom. )

X ² is a divalent organic group. More specifically, X ² is a divalent organic group derived from a compound having two or more active hydrogen atoms in a molecule capable of undergoing an addition reaction with an isocyanate group or a thioisocyanate group. Organic groups such as polyalkylene glycols and polyalkylene thioglycol
, Polyesters, polyamides, polycarbonate
, Polyalkylenedicarboxylic acids, polyalkylenediols, and polyalkylenedimercaptans by removing two HX- groups (where X is the same as defined above). And a divalent organic group.

P is 0 or a number of 1 or more, preferably 0 or a number of 1 to 10. When p exceeds 10,
Since the viscosity of the polymerizable unsaturated group-modified hydrolyzable silane tends to increase, it may be difficult to handle.

R ⁵ is an n + 1-valent organic group, and is selected from, for example, chain, branched or cyclic saturated hydrocarbon groups, unsaturated hydrocarbon groups, and alicyclic organic groups. Also, n is 1
It is selected from positive integers of -20, preferably 1-10, and more preferably 3-5.

Y ¹ represents a monovalent organic group having a polymerizable unsaturated group which undergoes an intermolecular crosslinking reaction in the presence of an active radical species. Examples of such a group include an acryloxy group, a methacryloxy group, a vinyl group, a propenyl group, a butadienyl group, a styryl group, an ethynyl group, a cinnamoyl group, a maleate group and an acrylamide group. Among these, an acryloxy group can be mentioned as a preferable one.

The photopolymerization initiator is preferably selected from compounds that generate active radical species upon irradiation with ultraviolet rays, and is used in an amount of 0.1 to 100 parts by weight of the solid content of the curable composition.
1 to 10 parts by weight, preferably 1 to 5 parts by weight.

Specific examples of the photopolymerization initiator include 1-hydroxycyclohexylphenyl ketone, 2,2-dimethoxy-2-phenylacetophenone, xanthone, fluorenone, benzaldehyde, fluorene, anthraquinone, triphenylamine, carbazole, 3-methylacetophenone, 4-chloroacetophenone, 4,4 '
-Dimethoxyacetophenone, 4,4'-diaminobenzophenone, Michler's ketone, benzoinpropyl
Ter, benzoinethyl ether, benzyldimethylketal, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, 2-hydroxy-2-methyl-1-phenylpropane-1 -One, thioxanthone, diethylthioxanthone, 2-isopropylthioxanthone, 2-chlorothioxanthone, 2-
Examples thereof include methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one and 2,4,6-trimethylbenzoyldiphenylphosphine oxide. It can be used, but is not limited to this.

The electrophotographic photoreceptor of the present invention is reproduced by the method of reproducing the electrophotographic photoreceptor of the present invention (claim 2).

The electrophotographic photoreceptor of the present invention is characterized in that, in the electrophotographic photoreceptor reproduced by the method for reproducing the electrophotographic photoreceptor of the present invention, the reproduction processing layer on the photoreceptor has a weight concentration of 0.01%. % Or more and 10% or less of a charge transport material (claim 3).

Further, according to the electrophotographic photoreceptor of the present invention, in the electrophotographic photoreceptor reproduced by the electrophotographic photoreceptor reproducing method of the present invention, the thickness of the reproduction processing layer on the photoreceptor is 0.5 μm. It is not less than 10 μm and not more than 10 μm.

In the method for reproducing an electrophotographic photoreceptor of the present invention, when the electrophotographic photoreceptor is reproduced, the first non-alcoholic non-alcoholic type in which the charge transporting material is dissolved in a concentration of 0.5% or more by weight.
After the charge transport material is dissolved in the organic solvent, the first organic solvent in which the charge transport material is dissolved is diluted with an alcohol-based second organic solvent to a predetermined ratio, and the photo-curable coating material is dispersed and blended. The method further includes a step of applying a reprocessing layer to apply a coating material to the photoreceptor.

When the electrophotographic photoreceptor is regenerated, a photocuring step of mainly using ultraviolet light having a wavelength of 310 nm or less as a curing ultraviolet ray for drying and curing the applied reprocessing layer paint is included. It is a feature (claim 6).

In the method of reproducing an electrophotographic photoreceptor of the present invention, when the electrophotographic photoreceptor is reproduced, the first non-alcoholic non-alcoholic type in which the charge transport material is dissolved in a concentration of 0.5% or more by weight is used.
After the charge transport material is dissolved in the organic solvent, the first organic solvent in which the charge transport material is dissolved is diluted with an alcohol-based second organic solvent to a predetermined ratio, and the photo-curable coating material is dispersed and blended. In the step of applying a coating to the photoreceptor to apply a coating to the photoreceptor, and in drying and curing the applied coating for the regenerating treatment, a wavelength of 310 nm is mainly used as curing ultraviolet light.
And a photo-curing step using the following ultraviolet light.

The coating material for the reproduction processing layer of the electrophotographic photoreceptor of the present invention is prepared by dissolving the charge transport material in a first organic solvent other than an alcohol in which the charge transport material is dissolved in a concentration of 0.5% or more by weight. It is produced by diluting a first organic solvent in which a charge transport material is dissolved with an alcohol-based second organic solvent at a predetermined ratio and dispersing and preparing a photocurable coating material, and has a predetermined viscosity range. (Claim 8).

The chemical substance for forming a reclaimed layer used in the present invention has a good film-forming property, and can repair a damaged part, a defective part, and a worn part to restore the photosensitive layer to a nearly uniform state. It is possible.

According to the first and second aspects of the present invention, the silica particles having excellent printing durability are combined with the organic compound which is a main component of curing. As a result, a reproduction processing layer having excellent durability and printing durability can be obtained. Further, it is a paint containing a photopolymerization initiator, and is photocured using ultraviolet light of a predetermined wavelength. Therefore, the production time can be remarkably shortened as compared with the case where the reprocessing layer is formed by using a heat-curable paint. Furthermore, by combining the silica particles with the organic compound as the main component of curing, the regenerating layer having a thickness of 1 μm or more, which has low shrinkage during curing and excellent printing durability and scratch resistance after curing, is uniformly formed. A paint that can be produced has been realized.

According to the third aspect of the present invention, the charge transport material having a weight concentration of 0.01% or more and 10% or less is contained in the reproduction processing layer. As a result, the electrophotographic characteristics are improved as compared with the case where the non-added reproduction processing layer is used. Specifically, the sensitivity is improved and the residual potential is reduced. As a result, an electrophotographic photosensitive member having excellent electrophotographic characteristics and excellent durability can be realized. Further, by adding a charge transport material having good compatibility with the resin of the reproduction processing layer to the reproduction processing layer,
The uniformity is eliminated by eliminating the unevenness in strength in the reproduction processing layer.
As a result, it is possible to prevent the reproduction processing layer from being partially removed, and to effectively prevent the occurrence of image defects.

According to the fourth aspect of the present invention, the thickness of the reproduction processing layer is set to 0.5 μm or more and 10 μm or less. Thereby, the printing durability and durability are improved by laminating a reproduction processing layer on the organic photoreceptor, and the electrophotographic characteristics are optimized within a practical range.

According to the fifth aspect of the present invention, the charge transporting material is dissolved in an organic solvent in which the charge transporting material is relatively large. Then, the solvent in which the charge transporting material is dissolved is diluted with an alcohol-based solvent, and the photocurable coating material is dispersed to obtain a reprocessing layer coating material. By uniformly dissolving and hardening the charge transport material in the coating material which is hardly dissolved in the photocurable coating material in the coating preparation procedure, the charge transport material is dispersed without being uniformly deposited in the reprocessing layer,
Further, the photosensitive member can be manufactured without clouding.

According to the sixth aspect of the present invention, when the paint for the reprocessing layer is cured, the wavelength of the cured ultraviolet ray is mainly 31.
Ultraviolet light of 0 nm or less is used. By using ultraviolet light having a high absorption coefficient for the organic material, the ultraviolet light is absorbed near the surface. Since an organic material causes a photoisomerization reaction or a photodecomposition reaction with respect to ultraviolet light, when a photocurable coating material is used, problems such as deterioration of an organic photoreceptor, performance degradation, and an optical memory effect occur due to irradiation of ultraviolet light. On the other hand, by absorbing ultraviolet rays in the vicinity of the surface, the performance of the organic photoreceptor is prevented from deteriorating due to ultraviolet rays during curing of the photocurable paint, and as a result, an electrophotographic photosensitive member having excellent electrophotographic characteristics and excellent durability is obtained. We are making.

According to the invention of claim 7, according to claim 5,
Operations and effects similar to those of the inventions described in (6) and (7) are obtained.

According to the invention of claim 8, according to claim 5,
And a recycled coating material having a predetermined viscosity range. Even if the paint for the reclaimed layer is diluted with an organic solvent, the reclaimed layer can be reclaimed without lowering the durability of the reclaimed layer and the electrophotographic characteristics of the photoreceptor. Therefore, by adjusting the viscosity of the paint for the reprocessing layer to a predetermined range, it is possible to level the abrasion damage of the photoconductor once used. As a result, it is possible to recover the electrophotographic characteristics and the image characteristics which have been reduced due to the site defect of the photoconductor and reuse the photoconductor.

[0042]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view of a regenerated laminated electrophotographic photosensitive member according to an embodiment of the present invention. The laminated electrophotographic photoreceptor 10 of the present embodiment is configured by mainly laminating a charge generation layer 12, a charge transport layer 13, and a reproduction processing layer 14 on a conductive substrate 11. The conductive substrate 11 functions as an electrode of the electrophotographic photosensitive member and serves as a support for other layers, and may be in any form such as a cylindrical shape, a plate shape, and a film shape. The material of the conductive base 11 is not limited, and may be a metal such as aluminum, stainless steel, nickel, or the like. The conductive base 11 may be formed by depositing aluminum or gold, or coating a conductive polymer on an insulating base such as glass or plastic. It may be processed.

The charge generation layer 12 is formed of a deposited film of an organic photoconductive substance, a coating film in which an organic charge generation substance is dispersed in a binder resin, or the like. Upon receiving light, a charge is generated. The charge generation material has electrical characteristics such as high charge generation efficiency for the wavelength of light that can be used as a light source and high charge injection efficiency for the charge generation material used in the charge transport layer. Is preferred. As the charge generating substance, metal-free phthalocyanine, copper phthalocyanine, phthalocyanine compounds such as titanyl phthalocyanine, various azos, pigments such as quinone are used, and a suitable material is selected depending on the wavelength of the light source used and the combination with the charge transporting substance. You. The film thickness of the charge generation layer 12 is sufficient as long as it absorbs light from the light source and generates an amount of charge necessary to cancel the charge formed on the photoreceptor by corona discharge or the like. And the amount of dispersion in the binder resin or the generation efficiency. Generally 3μ
m, preferably 0.1 μm or more and 1 μm or less.

The charge transport layer 13 is formed by a coating film of a material in which an organic charge transport material is dispersed in a binder resin. The charge transport layer 13 has a function as an insulating layer in a dark place, and has a role of holding a charge produced by corona discharge or the like on the surface of the photoreceptor. In addition, the charge generation layer 12 has a function of transmitting sensitive light, and at the time of exposure, functions to transport the charge generated and injected in the charge transport layer 13 to neutralize and eliminate the charge on the surface of the photoreceptor. Organic compounds such as a hydrazone compound, a triphenylmethane compound, a triphenylamine compound, and a butadiene compound are used as the charge transport material. As the binder resin, materials such as polycarbonate resin, polyester resin, polyamide resin, polyurethane resin, silicone resin and epoxy resin are used, and mechanical durability, chemical stability, electrical stability,
Adhesion with other layers and compatibility with the charge transport material used are required. The thickness of the charge transport layer 13 is determined from requirements such as charge retention, charge transport speed, and mechanical durability, and is generally 50 μm or less, preferably 1 μm or less.
It is not less than 0 μm and not more than 30 μm.

The reproduction processing layer 14 is provided for repairing a damaged part, a defective part, and a worn part of the photoconductor. In addition, the reproduction processing layer 14 has a function of sufficiently withstanding mechanical friction due to cleaning or the like, has a function of retaining charges generated by corona discharge or the like on a surface in a dark place, and has a function of causing the charge generation layer 12 to be sensitive. It has the ability to transmit light.

A charge transport material is added to the reproduction processing layer 14 in order to reduce the electric resistance of the reproduction processing layer and improve the electrophotographic characteristics. As the charge transporting material added to the regenerating treatment layer, the same materials as those conventionally used for the charge transporting layer can be used. Specifically, as a charge transporting material to be added, hydrazone compounds, triphenylmethane compounds, triphenylamine compounds, bistriphenylamine styryl compounds, and organic compounds such as butadiene compounds can be used. It is preferable to use a triphenylamine compound or a bistriphenylamine styryl compound, which hardly causes decomposition and isomerization.

In the above, as one embodiment, the charge generation layer 12 is formed on the conductive base 11 made of, for example, aluminum.
Although the stack type electrophotographic photosensitive member 10 coated and laminated in the order of the charge transport layer 13 and the reproduction processing layer 14 has been described, the application of the reproduction processing method of the present invention is limited to the structure of the electrophotographic photosensitive member. Rather, it is not limited to the type of layer to be reproduced. That is, since the material used in the present invention has excellent adhesion to other materials and excellent durability, it is also suitable as a surface layer. For example, the present invention can also be applied as a method for regenerating a surface protection layer of a positively charged photoconductor in which a charge transport layer 13, a charge generation layer 12, and a surface protection layer are laminated on a conductive substrate 11 in this order. Further, the present invention can be applied as a method for regenerating a single-layer photoreceptor in which a charge transport material and a charge generation material are dispersed in the same layer.

Next, the reproduction processing method of the present invention will be described in detail according to the manufacturing procedure of FIG. FIG. 2 is a flowchart showing the procedure of the method for processing the electrophotographic photosensitive member of the present invention. In the reproduction processing method of the present invention, in order to add an appropriate amount of a charge transport material to the reproduction processing layer for the purpose of improving electrophotographic properties, the reproduction processing layer paint adjusting step S1, the coating step S2, the solvent drying step S3, and the ultraviolet curing. Step S4 is performed in this order, and the reprocessing layer paint adjusting step S1 includes a pre-dispersion processing step S1A of the charge transport material and a paint dispersion processing step S1B of the charge transport material.

In the charge transporting material pre-dispersion treatment step S1A, the charge transporting material to be added to the regenerating layer is 10% or more soluble and can be diluted with the organic solvent contained in the stock solution of the photocurable paint. The charge transport material is dissolved in a certain first organic solvent to prepare a concentrated solution of the charge transport material. Then, in the paint dispersion treatment step S1B of the charge transport material,
The charge transport material is difficult to dissolve, but the concentrated solvent prepared above is dispersed and diluted in a second organic solvent that is dilutable with respect to the organic solvent contained in the photocurable coating, and the photocurable coating stock solution is further diluted. Disperse to prepare paint for reclaimed layer. Specific examples of the first organic solvent include dichloromethane, tetrahydrofuran, and methyl ethyl ketone.
Specific examples of the organic solvent include alcohols such as isopropyl alcohol, methyl alcohol, and ethyl alcohol, and water.

In the electrophotographic photoreceptor of the present invention, a charge transport material is added to the reproduction processing layer 14 in order to improve electrophotographic characteristics. Therefore, it is required that the paint for producing the regenerating treatment layer 14 be mixed with an appropriate amount of the charge transport material. Although the reproduction processing layer 14 is often manufactured by dip coating for industrial reasons, the procedure for manufacturing the laminated photoconductor 10 shown in FIG. The charge transporting material is eluted from the charge transporting layer 13 into the organic solvent in which the coating material 14 is made into a paint. As described above, inconsistent properties such that the charge transport material is dissolved in an appropriate amount and does not dissolve from the charge transport layer 13 when the regenerating layer is coated are required in the regenerating layer coating.

Therefore, the pre-dispersion treatment step S of the charge transport material
A concentrated solution is prepared in 1A, and is diluted in an appropriate amount in an organic solvent in which the charge transporting material is difficult to dissolve in a subsequent paint dispersion treatment step S1B of the charge transporting material. By adjusting the paint in this procedure, elution of the charge transport material from the charge transport layer at the time of application of the regenerating layer is prevented, and an appropriate amount of the charge transport material is uniformly added to the regenerating layer 14 for compatibility. A paint that can be recycled is realized.

In the coating step S2, the prepared coating material for the reprocessing layer is applied to the used laminated photoreceptor (the charge generation layer 12, the charge transport layer 13
To the photoconductors laminated in this order. Examples of the application method include dip coating, spray coating, blade coating, and ring coating.

In the solvent drying step S3, the solvent which has been converted into the reprocessing layer is dried using a high-temperature drier, a reduced-pressure drier or the like. Drying conditions are not lower than room temperature and not higher than the temperature at which the coated photoreceptor is not denatured, and generally from 60 ° C to 150 ° C.

In the ultraviolet curing step S4, the coating film from which the solvent has been removed by drying is irradiated with ultraviolet light to react and cure the paint for the reprocessing layer. Although the curing ultraviolet wavelength varies depending on the photopolymerization initiator, a low-pressure mercury lamp, a high-pressure mercury lamp, a xenon lamp, or the like is generally used as a light source.

In the present invention, the curing ultraviolet wavelength is 310
The wavelengths below nm are mainly used. By using ultraviolet rays having a high absorption coefficient for the organic material, the ultraviolet rays are absorbed as much as possible near the surface. Since an organic material causes a photoisomerization reaction or a photodecomposition reaction with respect to ultraviolet light, when a photocurable coating material is used, problems such as deterioration of an organic photoreceptor, performance degradation, and an optical memory effect occur due to irradiation of ultraviolet light. By absorbing ultraviolet rays near the surface, the performance of the organic photoreceptor is prevented from deteriorating due to ultraviolet rays during curing of the photocurable coating material. As a result, the electrophotographic photoreceptor 10 having excellent electrophotographic characteristics and excellent durability can be manufactured.

As a light source of ultraviolet light having a wavelength of 310 nm or less, an excimer laser, 254.7 nm or 184.9 nm is used.
A low-pressure mercury lamp having a main radiation wavelength is known, but a low-pressure mercury lamp is preferable in the production of the electrophotographic photosensitive member 10 which needs to uniformly irradiate a relatively large area.

According to the above-mentioned reproduction processing method, a photocurable reproduction processing layer 14 to which a charge transport material is added, which has excellent electrophotographic characteristics and high durability, can be obtained. Also,
The paint used in the present reprocessing method can be reprocessed without reducing the durability of the reprocessing layer and the electrophotographic properties of the photoreceptor even when diluted with an appropriate organic solvent as described above. is there. Therefore, by adjusting the viscosity of the paint for the reprocessing layer to a predetermined range, it is possible to level the abrasion damage of the photoconductor once used. As a result, it is possible to recover the electrophotographic characteristics and the image characteristics which have been reduced due to the site defect of the photoconductor and reuse the photoconductor.

The viscosity of the paint for the reprocessing layer varies depending on the production method, production conditions, the size of the leveled abrasion, the produced film thickness, etc., but is generally preferably in the range of 1 cP to 500 cP, and is most commonly used industrially. In a dip coat which is a simple production method, 1 cP to 200 cP is preferable.

The preferred film thickness of the reproduction processing layer 14 greatly varies depending on the developing method and required performance. Further, since it differs depending on the depth of the wear scar generated by use, it differs depending on the site of the photoconductor. The film thickness of the reproduction processing layer is also generally 10 μm or less, preferably 0.5 μm or more and 5 μm or less at the leveling portion.
For photoreceptors that require a large area, it is difficult to produce a film with a uniform thickness that does not cause image quality unevenness when the thickness is 0.5 μm or less, and durability and printing durability against developing rollers and paper. Will be lower. On the other hand, if it exceeds 5 μm, the electrophotographic characteristics are greatly reduced, and more specifically, problems such as an increase in residual potential and a decrease in sensitivity occur, and the photoconductor is not suitable for practical use. Also, at the leveling site, 10μ
If m or more, the potential decay becomes insufficient depending on the printing speed, and image defects may occur.

[0060]

The effects of the present invention will be described below with reference to specific examples. (Preparation Example 1) As a charge generation layer 12, a 30 mm diameter aluminum tube 11 was immersed in a solution in which a charge generation substance titanyl phthalocyanine and a butyral resin as a binder resin were dissolved in a tetrahydrofuran (THF) solvent to prepare a coating film. The thickness after drying was about 0.25 μm. On the charge generation layer 12 thus obtained, the following structure

Embedded image Using a charge transport layer paint obtained by dissolving a charge transport material bistriphenylamine styryl compound and a binder resin polycarbonate (trade name: Z200, manufactured by Mitsubishi Gas Chemical Co., Ltd.) in a THF solvent, the film thickness after drying by an immersion method is about The charge transport layer 13 was formed to have a thickness of 20 μm, and a photosensitive drum was prepared.

The photosensitive drum is mounted on a laser printer (A4
(6 sheets / minute) and A4 paper
000 sheets were printed. The photosensitive drum after printing 6,000 sheets was used as a reference drum before the application of the reproduction processing layer in the following examples.

Example 1 The same charge transporting material as the compound used in the charge transporting layer, 1 part by weight of a bistriphenylamine styryl compound, was sufficiently stirred and dissolved in 10 parts by weight of a THF solvent (pre-dispersion of the charge transporting material). Processing step S1A).
The obtained concentrated solution of the charge transport material is diluted and dispersed in 40 parts by weight of isopropyl alcohol, and further contains a composition mainly containing silica particles, an organic compound chemically bonded to the silica particles, and a photopolymerization initiator. 50 parts by weight of Desolite Z7501 (manufactured by JSR Corporation) was added as a stock solution of the paint, and the mixture was sufficiently stirred to prepare a paint for a reprocessing layer (paint dispersion process of charge transport material S1B). In the paint for the reprocessing layer produced by this method, the charge transport material was completely dissolved and no precipitation was observed.

The obtained reprocessing layer paint was dip-coated on the used photosensitive drum prepared in Preparation Example 1 (coating step S).
2). After drying at 90 ° C. for 20 minutes (solvent drying step S3), ultraviolet rays were irradiated for 1 minute using a low-pressure mercury lamp (ultraviolet curing step S4) to obtain a reproduction treatment layer 14 having a thickness of about 1 μm.
A scratch test of the reproduction processing layer 14 was performed to confirm the curing of the reproduction processing layer 14 and the adhesion to the charge transport layer 13, thereby obtaining a drum-type electrophotographic photosensitive member 10 of the present invention. The charge generation layer 1 of the electrophotographic photoreceptor thus manufactured
2. No cracks or cracks were generated on the surfaces of the charge transport layer 13 and the reproduction processing layer 14, and no cloudiness or crystallization was observed in each layer.

(Embodiment 2) Under the same conditions as in Embodiment 1, a reproduction processing layer 14 was dip-coated on the used photoreceptor using the same reproduction processing layer paint as in Example 1. In this case, the reprocessing layer 14 was produced by controlling the lifting speed in the dip coating so that the film thickness after drying and curing was 3 μm. No cracks or cracks occurred on the surfaces of the charge generation layer 12, the charge transport layer 13, and the reproduction processing layer 14 of the electrophotographic photoreceptor thus manufactured, and no clouding or crystallization was observed in each layer. Was.

(Embodiment 3) Under the same conditions as in Embodiment 1, a reproduction processing layer 14 was dip-coated on the used photoreceptor using the same reproduction processing layer paint as in Example 1. In this case, the reprocessing layer 14 was produced by controlling the pull-up speed in the dip coating so that the film thickness after drying and curing became 5 μm. No cracks or cracks occurred on the surfaces of the charge generation layer 12, the charge transport layer 13, and the reproduction processing layer 14 of the electrophotographic photoreceptor thus manufactured, and no clouding or crystallization was observed in each layer. Was.

(Example 4) Under the same conditions as in Example 1, a reproduction processing layer 14 was dip-coated on the used photoreceptor using the same reproduction processing layer paint as in Example 1. In this case, the reprocessing layer 14 was produced by controlling the lifting speed in the dip coating so that the film thickness after drying and curing became 10 μm. The charge generation layer 12 of the electrophotographic photoreceptor thus manufactured,
No cracks or cracks were formed on the surfaces of the charge transport layer 13 and the regenerating layer 14, and no cloudiness or crystallization was observed in each layer.

(Example 5) Except that the mixing ratio of the charge transporting material bistriphenylamine styryl compound in the coating of the reproduction processing layer was 0.5 part by weight when the reproduction processing layer 14 was formed on the used photoreceptor. Prepared the reproduction processing layer 14 under the same conditions as in Example 1, and prepared the electrophotographic photosensitive member 1 of the present invention.
0 was obtained. No cracks or cracks occurred on the surfaces of the charge generation layer 12, the charge transport layer 13, and the reproduction processing layer 14 of the electrophotographic photoreceptor thus manufactured, and no clouding or crystallization was observed in each layer. Was.

(Example 6) Except that the mixing ratio of the charge transporting material bistriphenylamine styryl compound in the paint for the reproduction processing layer was 0.1 part by weight when the reproduction processing layer 14 was formed on the used photoreceptor. Prepared the reproduction processing layer 14 under the same conditions as in Example 1, and prepared the electrophotographic photosensitive member 1 of the present invention.
0 was obtained. No cracks or cracks occurred on the surfaces of the charge generation layer 12, the charge transport layer 13, and the reproduction processing layer 14 of the electrophotographic photoreceptor thus manufactured, and no clouding or crystallization was observed in each layer. Was.

(Example 7) On the photoreceptor used, the charge transport material in the paint for the reproduction processing layer was prepared to have the following structure when the reproduction processing layer 14 was produced.

Embedded image A reproduction processing layer 14 was prepared under the same conditions as in Example 1 except that the mixing ratio of the triphenylamine compound was 0.5 part by weight, to obtain an electrophotographic photoreceptor 10 of the present invention.
No cracks or cracks occurred on the surfaces of the charge generation layer 12, the charge transport layer 13, and the reproduction processing layer 14 of the electrophotographic photoreceptor thus manufactured, and no clouding or crystallization was observed in each layer. Was.

(Measurement Example) The drum-type electrophotographic photosensitive member of the above embodiment was inserted into the same cartridge as that described in the preparation example, and printing was performed on 6,000 sheets in addition to the previous printing. Table 1 summarizes the results of evaluating the print quality of the second and 6000 sheets after the start of printing. As shown in Table 1, in the case of Production Example 1, partial fog has already occurred due to printing on 6000 sheets, and the image quality has been degraded (Second Production Example). It turns out that it returned and improved (Examples 1-3). Further, when printing was performed on 6000 sheets, a lot of noises such as fogging and image missing in the printed matter increased in the production example, and it became completely difficult to use the 6000th sheet. However, in Examples 1 to 7 which are the electrophotographic photosensitive members of the present invention, 600
It has good print quality even after printing 0 sheets, and it was concluded that the electrophotographic photosensitive member was reproduced by the reproduction processing method of the present invention and could be reused.

[Table 1]

[0071]

According to the present invention, a used electrophotographic photoreceptor or a scratched electrophotographic photoreceptor is regenerated and a damaged portion,
An effect of repairing a defective portion or a worn portion and obtaining a reusable electrophotographic photosensitive member can be obtained. Further, it is possible to reduce the number of regeneration steps and materials used, and to reduce the production cost of the photoreceptor, as compared with the conventional method of regenerating only the aluminum tube by burning the used photoreceptor drum. Furthermore, since the regeneration method does not involve the incineration of organic substances, toxic gases such as dioxin, which have been a problem in recent years, are not generated, and the regeneration is safe and the industrial advantages are great.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a regenerated laminated electrophotographic photosensitive member according to an embodiment of the present invention.

FIG. 2 is a flowchart illustrating an example of a reproduction processing method for an electrophotographic photosensitive member according to the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 electrophotographic photoreceptor 11 support base 12 charge generation layer 13 charge transport layer 14 regeneration processing layer S1 regeneration processing layer paint adjustment step S1A charge transport material pre-dispersion processing step S1B charge transport material paint dispersion processing step S2 coating step S3 solvent Drying process S4 UV curing process

Continuation of the front page (51) Int.Cl. ⁷ identification symbol FI G03G 5/147 503 G03G 5/147 503 504 504 (56) Reference JP 2000-242018 (JP, A) JP 2000-10321 (JP, A) JP-A-5-281775 (JP, A) JP-A-4-273248 (JP, A) JP-A-2000-199975 (JP, A) JP-A-4-97157 (JP, A) JP-A-54-1979 148537 (JP, A) JP-A-4-110951 (JP, A) JP-A-4-37765 (JP, A) JP-A-60-104953 (JP, A) JP-A-1-116553 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) G03G 5/00

Claims (8)

(57) [Claims] 1. A method for regenerating an electrophotographic photoreceptor after use or having damage, comprising a polymerizable unsaturated group, a group represented by the following formula (1) and a group represented by the following formula (2): 1) (Wherein X is selected from -NH-, -O- and -S-,
Y is selected from an oxygen atom and a sulfur atom. However, when X is -O-, Y is a sulfur atom. 1) selected from
An organic compound having at least one species, silica particles bonded to the organic compound via a silyloxy group, and a composition mainly containing a photopolymerization initiator, applied to the photoreceptor as a reprocessing layer paint, A method for reproducing an electrophotographic photosensitive member, comprising repairing a damaged portion, a defective portion, or a worn portion to produce a reusable electrophotographic photosensitive member. 2. An electrophotographic photosensitive member reproduced by the method according to claim 1. 3. The electrophotographic photoreceptor reproduced by the method according to claim 1, wherein the reproduction processing layer on the photoreceptor contains a charge transport material having a weight concentration of 0.01% or more and 10% or less. The electrophotographic photosensitive member according to claim 2, wherein: 4. The electrophotographic photoreceptor reproduced by the method according to claim 1, wherein the thickness of the reproduction processing layer on the photoreceptor is 0.5 μm or more and 10 μm or less. 3. The electrophotographic photosensitive member according to 3. 5. When the charge transporting material is dissolved in a first organic solvent other than an alcoholic solvent in which the charge transporting material dissolves in a concentration of 0.5% or more by weight when reproducing the electrophotographic photoreceptor,
A regenerating layer coating step of diluting the first organic solvent in which the charge transport material is dissolved with an alcohol-based second organic solvent at a predetermined ratio and dispersing and preparing a photocurable coating to apply a regenerating layer paint to a photoreceptor; The method for reproducing an electrophotographic photosensitive member according to claim 1, comprising: 6. A method for regenerating an electrophotographic photoreceptor, comprising a step of drying and curing an applied reprocessing layer paint, which includes a photo-curing step mainly using ultraviolet light having a wavelength of 310 nm or less as curing ultraviolet rays. The method for reproducing an electrophotographic photosensitive member according to claim 1. 7. When reproducing the electrophotographic photoreceptor, after dissolving the charge transport material in a first organic solvent other than an alcohol-based solvent in which the charge transport material is dissolved in a concentration of 0.5% or more by weight,
A regenerating layer coating step of diluting the first organic solvent in which the charge transport material is dissolved with an alcohol-based second organic solvent at a predetermined ratio and dispersing and preparing a photocurable coating to apply a regenerating layer paint to a photoreceptor; 2. The electrophotography according to claim 1, further comprising: a drying step of drying and curing the applied reprocessing layer paint, and a photo-curing step of mainly using ultraviolet light having a wavelength of 310 nm or less as curing ultraviolet light. Reproduction method of photoconductor. 8. A method in which a charge transport material is dissolved in a first organic solvent other than an alcoholic solvent in which the charge transport material is dissolved in a concentration of 0.5% or more by weight, and then the first charge transport material is dissolved.
A reproduction process for an electrophotographic photoreceptor, which is produced by dispersing an organic solvent to a predetermined ratio with an alcohol-based second organic solvent and dispersing and preparing a photocurable coating material, and having a predetermined viscosity range. Layer paint.