JP4785661B2 - Electrophotographic photosensitive member, method for producing the same, process cartridge, and electrophotographic apparatus - Google Patents

Description

  The present invention relates to an electrophotographic photosensitive member and a manufacturing method thereof, an electrophotographic process cartridge, and an electrophotographic apparatus. The electrophotographic photosensitive member, process cartridge and electrophotographic apparatus of the present invention are applied to a copying machine, a facsimile, a laser printer, a direct digital plate making machine and the like.

  More than 10 years have passed since the adoption of the agenda 21 “Agenda 21”, which was established with the hope of passing on the rich global environment to offspring. For example, it can be said that it is a familiar example of consciousness change that garbage has been separated and that backing paper has been used frequently as printing paper. At present, the environmental performance of industrial products is becoming more and more important to the public. In recent years, electrophotographic photoconductors have been energetically researched and developed to reduce environmental impact. When looking at the life cycle from raw material mining to disposal of the electrophotographic photosensitive member, it is necessary to promote the extension of the life and detoxification of the health of the electrophotographic photosensitive member first.

Conventionally, the usage of electrophotographic photoreceptors has a strong character as a supply product, so there is room for improvement in resource saving and waste reduction. In order to cope with this, it is important to improve the durability of the photosensitive member by suppressing the wear and wound of the photosensitive member from the viewpoint of designing and using the photosensitive member.
At present, an amorphous silicon photoconductor can be cited as a typical high durability photoconductor. However, since the manufacturing method is a dry process, the manufacturing cost is high, and the object of use is limited to high-end machines with some exceptions. The high durability of the amorphous silicon photoconductor is considered to have not contributed to reducing the environmental load more than feeling because the ratio of use to the whole is small. In order to reduce the environmental load, it is necessary to reduce the cost in addition to increasing the durability of the photoreceptor because it is necessary to increase the usage ratio. For this purpose, it is advantageous to select a low-cost organic photoreceptor that is highly durable.

  Changes in binder resin for high durability of organic photoreceptors (for example, Non-Patent Document 1, Hiroyuki Tamura, Saeko Takahashi, Hironobu Morishita, Hideharu Sakamoto, Haruo Shikuma, Japan Hardcopy '97 Fall Meeting, 25-28, 1997) , High molecular weight of charge transport material (for example, Patent Document 1, JP-A-7-325409), coating of curable protective layer containing high hardness filler (for example, Patent Document 2, JP-A-2002-258499), crosslinking Formation of a resin film on the surface of the photoreceptor (for example, Patent Document 3, JP 2000-66424 A), deposition of a sol-gel cured film on the surface of the photoreceptor (for example, Patent Document 4, JP 2000-171990 A) Publication). Each of these measures has advantages and disadvantages. In particular, the last two types of measures that have a cross-linked structure are that the coating is formed by multiple chemical bonds, so even if the coating is stressed and part of the chemical bond breaks, it immediately progresses to wear. There is no. Among the above, it is considered to be a particularly rational measure. For convenience, these measures will be classified as “curing type protective layers”.

  If extremely high wear resistance is imparted to the photoreceptor, scratch resistance is required at the same time. This is because when a scratch occurs on the surface of the photoreceptor, the discharge hazard in the electrophotographic process concentrates on the wound portion and causes alteration of the portion. Further, image defects such as background stains and image blur are likely to occur locally because the developer component containing toner and paper dust are buried in the groove formed by the wound. If the surface of the photoconductor becomes extremely sharp, scratches once generated are unlikely to disappear over time as if they were stamped. For this reason, the wound prevents the long life of the photoreceptor.

  By the way, in recent full-color electrophotographic apparatuses, a case where polymerized toner is used is becoming mainstream because of high image quality and environmental performance. The sharpness of the image improves as the degree of sphericity of the polymerized toner increases. On the other hand, in the toner recovery method using the cleaning blade, the probability that the toner slips through the blade increases. This is an abnormality in the electrophotographic process that forms streak-like image noise. On the other hand, it has been found that the cleaning function can be ensured by blending silica powder into the toner for damming purposes at the blade portion of the toner (for example, JP-A-2002-318467). In an electrophotographic apparatus using the above high abrasion resistance photoreceptor and a polymerized toner containing this special silica powder, silica may cause a wound on the surface of the photoreceptor, or the silica itself may pierce the photoreceptor surface. It often accumulates on the surface of the photoreceptor. An example showing this aspect is shown in FIG. It is a cross-sectional curve by the surface roughness measurement of the photoreceptor in the state where the silica was stuck. As a result, the wear resistance performance of the photoreceptor cannot be used.

For example, there has been proposed a technique for improving the releasability between silica and the surface of the photoconductor by reducing the surface energy of the photoconductor, and preventing wounding and filming of silica (for example, Japanese Patent Application Laid-Open No. H10-260688) 2005-62830). However, the wear resistance often deteriorates in the application of this technology. Although it is desired that the high abrasion resistance photoconductor is not damaged at the same time, it is desired to enhance the mechanical strength, but there is no technology that can respond to this.
Hiroyuki Tamura, Saeko Takahashi, Hironobu Morishita, Hideharu Sakamoto, Haruo Shikuma, Japan Hardcopy '97 Fall Meeting, 25-28, 1997 JP 7-325409 A JP 2002-258499 A JP 2000-66424 A JP 2000-171990 A JP 2002-318467 A JP 2005-62830 A

  An object of the present invention is to provide an electrophotographic photosensitive member that can form a high-quality color image and does not cause wounds on the surface of the photosensitive member and filming of silica with respect to the electrophotographic photosensitive member that is extremely excellent in abrasion resistance. To do.

  The inventor has found that mixing an organosilica sol is advantageous for solving the above-mentioned problem in an electrophotographic photoreceptor having a radical polymerizable cured film on the surface of the photoreceptor. Furthermore, by mixing these materials, it was confirmed that no cracks or film peeling occurred, and the present invention was completed.

That is, according to the present invention,
(1) the cross-linked resin surface layer of the electrophotographic photosensitive member, an electrophotographic photoreceptor, characterized by containing a crosslinked and organosilica cured film of trimethylolpropane triacrylate and photocurable charge transport material.
(2) An electrophotographic photoreceptor comprising a crosslinked resin surface layer of an electrophotographic photoreceptor containing a crosslinked body of trimethylolpropane triacrylate and a crosslinked body of organosilica and a thermosetting charge transport material. .
( 3 ) The electrophotographic photosensitive member according to (1), wherein the cross-linked resin surface layer of the electrophotographic photosensitive member is cured together with caprolactone-modified dipentaerythritol hexaacrylate or dipentaerythritol hexaacrylate.

（一般式１中、ｄ、ｅ、ｆはそれぞれ０または１の整数、Ｒ₁₃は水素原子、メチル基を表し、Ｒ₁₄、Ｒ₁₅は水素原子以外の置換基で炭素数１〜６のアルキル基を表し、複数の場合は異なってもよい。ｇ、ｈは０〜３の整数を表す。Ｚは単結合、メチレン基、エチレン基、

を表す。） ( 4 ) The cross-linked resin surface layer of the electrophotographic photosensitive member contains at least a cross-linked product of a photocurable charge transport material of the following general formula 1 in a proportion of 5 wt% or more and less than 60 wt% ( The electrophotographic photosensitive member according to 1) or ( 3 ).

(In General Formula 1, d, e and f are each an integer of 0 or 1, R ₁₃ represents a hydrogen atom or a methyl group, and R ₁₄ and R ₁₅ are substituents other than a hydrogen atom and are alkyls having 1 to 6 carbon atoms. Represents a group and may be different in a plurality of cases, g and h each represent an integer of 0 to 3. Z represents a single bond, a methylene group, an ethylene group,

Represents. )

｛一般式２中、Ｒ₂とＲ₃およびＲ₄は水素原子、置換もしくは無置換のアルキル基、またはアリール基を表す。Ａｒ₁とＡｒ₂はアリール基を表す。
Ｘは下記（ａ）〜（ｃ）のいずれかを表す。
（ａ）アルキレン基
（ｂ）アリーレン基
（ｃ）下記一般式（５）で表される基

（式中、Ｙは−Ｏ−、−Ｓ−、−ＳＯ−、−ＳＯ₂−、−ＣＯ−及び以下の２価基を表す。

ここで、ｐは１〜１２の整数を表す。）｝ (5) The cross-linked resin surface layer of the electrophotographic photosensitive member contains at least a cross-linked product of a thermosetting charge transport material of the following general formula 2 or 3 in a proportion of 5 wt% or more and less than 60 wt%. The electrophotographic photosensitive member according to claim 2.

{In General Formula 2, R ₂ , R ₃ and R ₄ represent a hydrogen atom, a substituted or unsubstituted alkyl group, or an aryl group. Ar ₁ and Ar ₂ represent an aryl group.
X represents any of the following (a) to ( c ).
(A) alkylene group
(B) Arylene group
(C) Group represented by the following general formula (5)

(Wherein, Y is -O -, - S -, - SO -, - SO 2 -, - CO- and represent a divalent group of the following.

Here, p represents an integer of 1 to 12. )}

（一般式３中、Ｒ₉、Ｒ₁₀は置換もしくは無置換のアリール基を表す。Ｒ₉、Ｒ₁₀は同一であっても異なってもよい。また、Ａｒ₆、Ａｒ₇はアリーレン基を表し、Ｒ₉およびＲ₁₀と同様のアリール基の２価基が挙げられ、同一であっても異なってもよい。Ｘは一般式２で挙げたＸと同じである。）

(In General Formula 3, R ₉ and R ₁₀ represent a substituted or unsubstituted aryl group. R ₉ and R ₁₀ may be the same or different. Ar ₆ and Ar ₇ represent an arylene group. , R ₉ and R ₁₀ may be the same or different, and may be the same or different.X is the same as X in the general formula 2.)

( 6 ) The content of the cured organosilica film contained in the cross-linked resin surface layer of the electrophotographic photosensitive member is 10 wt% or more and less than 90 wt%, wherein any one of (1) to ( 5 ) The electrophotographic photosensitive member described.
( 7 ) The electrophotographic photosensitive member according to any one of (1) to ( 6 ), wherein the cross-linked resin surface layer of the electrophotographic photosensitive member contains no metal oxide fine particles.

（一般式４中Ｒ₁はアルキル基を表す。） ( 8 ) A solvent containing at least a compound represented by the following general formula 4 is used on the photosensitive layer of the electrophotographic photosensitive member, and contains a trimethylolpropane triacrylate, an organosilica, and a heat or photocurable charge transport material. The coating solution is applied, exposed to heat and dried to cause a crosslinking reaction of the coating solution, and the solvent is removed to form a crosslinked resin surface layer having a thickness of 3 μm or more and less than 15 μm. The method for producing an electrophotographic photosensitive member according to any one of (1) to ( 7 ).

(In general formula 4, R ₁ represents an alkyl group.)

( 9 ) A process cartridge on which the electrophotographic photosensitive member according to any one of (1) to ( 7 ) is mounted.
( 10 ) At least an electrophotographic photosensitive member according to any one of (1) to ( 7 ) or a process cartridge according to ( 9 ) is mounted.
( 11 ) The electrophotographic apparatus according to ( 10 ), wherein the electrophotographic apparatus has a developing station of at least two colors, is a tandem type, and further develops using a polymerized toner.

  An acrylic resin mainly composed of trimethylolpropane triacrylate (TMPTA) exhibits high hardness. In order to further toughen this material, it is advantageous to add a metal oxide filler. However, this technique has a detrimental effect of damaging the cleaning blade, and it is necessary to add an additional technique for use. It is presumed that large irregularities on the surface of the photoreceptor due to the cueing of the filler have an influence.

  On the other hand, when the organosilica sol is blended, the glass component can be mixed on the surface of the photoreceptor without increasing the surface roughness. This eliminates the above inconvenience. A number of techniques for applying a cured organosilica sol film to the surface of a photoreceptor have been proposed. A large amount of uncured silanol is likely to absorb moisture, which may cause the surface resistance of the photoreceptor to decrease. However, this problem tends to be compressed in the configuration of the present application. It seems that the acrylic component is working.

  Moreover, when forming a radical polymerizable cured film, a coating film emits strong radiant heat. Excess energy is thought to damage the underlying photosensitive layer. For this reason, in the film forming process, care must be taken to suppress this damage by water-cooling the photosensitive member support or using both air cooling and intermittent exposure.

In the structure of the present invention, radiant heat generated when a cured film is formed by exposure is absorbed by the crosslinking reaction of the organosilica sol, so that damage to the photosensitive layer due to radiant heat is reduced. Of course, it is preferable to add the above control in the film forming process, but the present invention can greatly contribute to the suppression of the yield in the production.
In the present invention, the crosslinkable resin surface layer refers to a protective layer formed on the surface of the electrophotographic photosensitive member, and may be hereinafter referred to as a curable protective layer.

  The present invention is not only extremely excellent in abrasion resistance, but also has high practical value that can form a high-quality color image using polymerized toner and prevent wounding of the photoreceptor surface and filming of silica. A photoreceptor is provided.

Hereinafter, the electrophotographic photosensitive member of the present invention will be described in detail with reference to the drawings.
FIG. 7 is a cross-sectional view schematically showing an example of an electrophotographic photosensitive member having still another layer structure of the present invention. On the conductive support 21, a charge generation layer 25, a charge transport layer 26, and a curable protective layer are shown. 28 is provided.
FIG. 8 is a cross-sectional view schematically showing an example of an electrophotographic photosensitive member having still another layer structure of the present invention, in which an undercoat layer 24 is provided between the conductive support 21 and the charge generation layer 25. A charge transport layer 26 and a curable protective layer 28 are provided on the charge generation layer 25.

Examples of the conductive support 21 include those having a volume resistance of 10 ¹⁰ Ω · cm or less, such as metals such as aluminum, nickel, chromium, nichrome, copper, silver, gold, platinum, and iron, tin oxide, and indium oxide. Oxide such as film or cylindrical plastic or paper coated by vapor deposition or sputtering, or a plate made of aluminum, aluminum alloy, nickel, stainless steel, etc., and drawing ironing method or impact ironing method. It is possible to use a tube that has been subjected to surface treatment by cutting, superfinishing, polishing, or the like after being made into a bare tube by a method such as the Extruded Ironing method, the Extruded Drawing method, or the cutting method.

In the electrophotographic photoreceptor used in the present invention, an undercoat layer 24 can be provided between the conductive support and the photosensitive layer. The undercoat layer is provided for the purpose of improving adhesiveness, preventing moire, improving coatability of the upper layer, and preventing charge injection from the conductive support.
The undercoat layer usually contains a resin as a main component. Usually, since the photosensitive layer is applied on the undercoat layer, the resin used for the undercoat layer is preferably a thermosetting resin that is hardly soluble in an organic solvent. In particular, polyurethane, melamine resin, and alkyd-melamine resin are particularly preferable materials because many of them sufficiently satisfy the above purpose. The resin can be used as a coating material which is appropriately diluted with a solvent such as tetrahydrofuran, cyclohexanone, dioxane, dichloroethane, butanone and the like.

In addition, fine particles such as metal or metal oxide may be added to the undercoat layer in order to adjust conductivity and prevent moire. In particular, titanium oxide is preferably used.
The fine particles are dispersed in a ball mill, attritor, sand mill or the like using a solvent such as tetrahydrofuran, cyclohexanone, dioxane, dichloroethane, or butanone to obtain a coating material in which the dispersion and the resin component are mixed.
The undercoat layer is formed by depositing the above-mentioned paint on a support by a dip coating method, spray coating method, bead coating method or the like and, if necessary, heat curing.
In many cases, the thickness of the undercoat layer is suitably about 2 to 5 μm. When the accumulation of the residual potential of the photoconductor becomes large, it is preferable to make it less than 3 μm.

The photosensitive layer in the present invention is preferably a laminated photosensitive layer in which a charge generation layer and a charge transport layer are sequentially laminated.
Of the layers in the multilayer photoconductor, the charge generation layer 25 will be described. The charge generation layer refers to a part of the laminated photosensitive layer and has a function of generating charges by exposure. This layer is mainly composed of a charge generating substance among the contained compounds. For the charge generation layer, a binder resin may be used as necessary. As the charge generation material, inorganic materials and organic materials can be used.

Examples of the inorganic material include crystalline selenium, amorphous selenium, selenium-tellurium, selenium-tellurium-halogen, selenium-arsenic compound, and amorphous silicon. In amorphous silicon, a dangling bond that is terminated with a hydrogen atom or a halogen atom, or a material that is doped with a boron atom or a phosphorus atom is preferably used.
On the other hand, as the organic material, known materials can be used, for example, metal phthalocyanine such as titanyl phthalocyanine and chlorogallium phthalocyanine, metal-free phthalocyanine, azulenium salt pigment, squaric acid methine pigment, symmetric type having a carbazole skeleton. Alternatively, an asymmetric azo pigment, a symmetric or asymmetric azo pigment having a triphenylamine skeleton, a symmetric or asymmetric azo pigment having a fluorenone skeleton, a perylene pigment, and the like can be given. Among these, metal phthalocyanines, symmetric or asymmetric azo pigments having a fluorenone skeleton, symmetric or asymmetric azo pigments having a triphenylamine skeleton, and perylene pigments have a high quantum efficiency of charge generation, and thus are suitable for the present invention. It is suitable as a material to be used. These charge generation materials may be used alone or as a mixture of two or more.

  Binder resins used as necessary for the charge generation layer include polyamide, polyurethane, epoxy resin, polyketone, polycarbonate, polyarylate, silicone resin, acrylic resin, polyvinyl butyral, polyvinyl formal, polyvinyl ketone, polystyrene, poly-N- Examples thereof include vinyl carbazole and polyacrylamide. Moreover, the polymeric charge transport material mentioned later can also be used. Of these, polyvinyl butyral is often used and is useful. These binder resins may be used alone or as a mixture of two or more.

Methods for forming the charge generation layer are roughly classified into a vacuum thin film preparation method and a casting method from a solution dispersion system.
Examples of the former method include a vacuum deposition method, a glow discharge decomposition method, an ion plating method, a sputtering method, a reactive sputtering method, and a CVD (chemical vapor deposition) method. Can be formed satisfactorily.
In addition, in order to provide the charge generation layer by the casting method, the above-described inorganic or organic charge generation material may be combined with a binder resin, if necessary, using a solvent such as tetrahydrofuran, cyclohexanone, dioxane, dichloroethane, butanone, ball mill, attritor. The dispersion may be dispersed by a sand mill or the like, and the dispersion may be diluted appropriately. Among these solvents, methyl ethyl ketone, tetrahydrofuran, and cyclohexanone are preferable because they have a lower environmental impact than chlorobenzene, dichloromethane, toluene, and xylene. The application can be performed by a dip coating method, a spray coating method, a bead coating method, or the like.

The thickness of the charge generation layer provided as described above is usually about 0.01 to 5 μm.
When it is necessary to reduce the residual potential and increase the sensitivity, these characteristics are often improved by increasing the thickness of the charge generation layer. On the other hand, the chargeability often deteriorates, such as the charge charge retention and space charge formation. From these balances, the thickness of the charge generation layer is more preferably in the range of 0.05 to 2 μm.
Further, if necessary, low-molecular compounds such as antioxidants, plasticizers, lubricants and ultraviolet absorbers and leveling agents described later can be added to the charge generation layer. These compounds can be used alone or as a mixture of two or more. When a low molecular weight compound and a leveling agent are used in combination, sensitivity deterioration often occurs. For this reason, the amount of these used is generally 0.1 to 20 phr, preferably 0.1 to 10 phr, and the amount of the leveling agent used is suitably about 0.001 to 0.1 phr.

The charge transport layer refers to a part of the laminated photosensitive layer that functions to inject and transport charges generated in the charge generation layer and to neutralize the surface charge of the photoreceptor provided by charging. The main component of the charge transport layer can be said to be a charge transport component and a binder component that binds the charge transport component.
Examples of materials that can be used for the charge transport material include low molecular weight electron transport materials, hole transport materials, and polymer charge transport materials.
Examples of the electron transporting material include electron accepting materials such as asymmetric diphenoquinone derivatives, fluorene derivatives, and naphthalimide derivatives.
These electron transport materials may be used alone or as a mixture of two or more.
As the hole transport material, an electron donating material is preferably used.
Examples thereof include oxazole derivatives, oxadiazole derivatives, imidazole derivatives, triphenylamine derivatives, butadiene derivatives, 9- (p-diethylaminostyrylanthracene), 1,1-bis- (4-dibenzylaminophenyl) propane, Examples include styryl anthracene, styryl pyrazoline, phenylhydrazones, α-phenyl stilbene derivatives, thiazole derivatives, triazole derivatives, phenazine derivatives, acridine derivatives, benzofuran derivatives, benzimidazole derivatives, and thiophene derivatives.
These hole transport materials may be used alone or as a mixture of two or more.

  Moreover, the polymeric charge transport material represented below can be used. For example, a polymer having a carbazole ring such as poly-N-vinylcarbazole, a polymer having a hydrazone structure exemplified in JP-A-57-78402, etc., exemplified in JP-A-63-285552, etc. The polysilylene polymer to be used, and aromatic polycarbonates exemplified by general formula (1) to general formula (6) of JP-A No. 2001-330973. These polymer charge transport materials can be used alone or as a mixture of two or more. In particular, the exemplified compounds disclosed in JP-A-2001-330973 are useful because of their good electrostatic characteristics.

  When a curable protective layer is laminated, the polymer charge transport material has less bleeding of the components constituting the charge transport layer into the crosslinkable resin surface layer than the low molecular weight charge transport material, and the crosslinkable resin surface layer It is a material suitable for preventing poor curing. In addition, since the charge transporting substance has a high molecular weight, it has excellent heat resistance, and is advantageous in that it is less susceptible to deterioration due to curing heat when a curable protective layer is formed.

Examples of the polymer compound that can be used as the binder component of the charge transport layer include polystyrene, polyester, polyvinyl, polyarylate, polycarbonate, acrylic resin, silicone resin, fluorine resin, epoxy resin, melamine resin, urethane resin, and phenol resin. And thermoplastic or thermosetting resins such as alkyd resins. Of these, polystyrene, polyester, polyarylate, and polycarbonate are useful because many of them have good charge transfer characteristics when used as a binder component of a charge transport component. In addition, since the curable protective layer is laminated on the charge transport layer, the charge transport layer is not required to have mechanical strength as compared with the conventional charge transport layer. For this reason, a material such as polystyrene, which is highly transparent but has a low mechanical strength and is difficult to apply in the prior art, can be effectively used as the binder component of the charge transport layer.
These polymer compounds can be used singly or as a mixture of two or more kinds, or as a copolymer composed of two or more kinds of these raw material monomers, and further copolymerized with a charge transport material.

When an electrically inactive polymer compound is used for modifying the charge transport layer, a cardo polymer type polyester having a bulky skeleton such as fluorene, a polyester such as polyethylene terephthalate or polyethylene naphthalate, or a C type polycarbonate is used. Polycarbonate in which the 3,3 ′ portion of the phenol component is alkyl-substituted with respect to a bisphenol-type polycarbonate, polycarbonate in which the geminal methyl group of bisphenol A is substituted with a long-chain alkyl group having 2 or more carbon atoms, biphenyl or biphenyl Polycarbonate having an ether skeleton, polycarbonate having a long chain alkyl skeleton such as polycaprolactone and polycaprolactone (for example, described in JP-A-7-292095), acrylic resin, polystyrene, hydrogenated porcine Diene is effective.
Here, the electrically inactive polymer compound refers to a polymer compound that does not include a chemical structure exhibiting photoconductivity such as a triarylamine structure.
When these resins are used in combination with a binder resin as an additive, the addition amount is preferably 50 wt% or less with respect to the total solid content of the charge transport layer due to restrictions on light attenuation sensitivity.

  When a low molecular charge transport material is used, the amount used is 40 to 200 phr, preferably about 70 to 100 phr. When a polymer charge transport material is used, a material in which the resin component is copolymerized in an amount of about 0 to 200 parts by weight, preferably about 80 to 150 parts by weight with respect to 100 parts by weight of the charge transport component is preferably used.

When two or more kinds of charge transport materials are contained in the charge transport layer, it is preferable that the difference in ionization potential is small. Specifically, by setting the difference in ionization potential to 0.10 eV or less, Can be prevented from becoming a charge trap of the other charge transport material.
Regarding the relationship between the ionization potentials, the difference between the charge transporting material contained in the charge transporting layer and the curable charge transporting material described later is preferably 0.10 eV.
In addition, the ionization potential value of the charge transport material in the present invention is a numerical value obtained by measuring by a general method using the atmospheric atmospheric ultraviolet photoelectron analyzer AC-1 manufactured by Riken Keiki Co., Ltd.

  In order to satisfy high sensitivity, the charge transport component is preferably added in an amount of 70 phr or more. In addition, α-phenylstilbene compounds, benzidine compounds, butadiene compound monomers, dimers, and polymer charge transport materials having these structures in the main chain or side chain are materials having high charge mobility. Many are useful.

  Examples of the dispersion solvent that can be used in preparing the charge transport layer coating solution include ketones such as methyl ethyl ketone, acetone, methyl isobutyl ketone, and cyclohexanone, ethers such as dioxane, tetrahydrofuran, and ethyl cellosolve, toluene, xylene, and the like. Examples include aromatics, halogens such as chlorobenzene and dichloromethane, and esters such as ethyl acetate and butyl acetate. Of these, methyl ethyl ketone, tetrahydrofuran, and cyclohexanone are preferable because they have a lower environmental impact than chlorobenzene, dichloromethane, toluene, and xylene. These solvents can be used alone or in combination.

The charge transport layer can be formed by dissolving or dispersing a mixture or copolymer mainly composed of a charge transport component and a binder component in an appropriate solvent, and applying and drying the mixture. As the coating method, a dipping method, a spray coating method, a ring coating method, a roll coater method, a gravure coating method, a nozzle coating method, a screen printing method, or the like is employed.
Since a curable protective layer is laminated on the upper layer of the charge transport layer, the thickness of the charge transport layer in this configuration need not be designed to increase the thickness of the charge transport layer in consideration of film scraping in actual use. Thus, it is possible to reduce the thickness.
The film thickness of the charge transport layer is practically about 15 to 40 μm, preferably about 15 to 30 μm for the purpose of ensuring the necessary sensitivity and charging ability.

  If necessary, low-molecular compounds such as antioxidants, plasticizers, lubricants and ultraviolet absorbers and leveling agents described later can be added to the charge transport layer. These compounds can be used alone or as a mixture of two or more. When a low molecular weight compound and a leveling agent are used in combination, sensitivity deterioration often occurs. For this reason, the amount of these used is generally 0.1 to 20 phr, preferably 0.1 to 10 phr, and the amount of the leveling agent used is suitably about 0.001 to 0.1 phr.

The cross-linked resin surface layer refers to a protective layer formed on the surface of the photoreceptor. The protective layer is coated with a coating solution, and then a resin having a crosslinked structure is formed by a polycondensation reaction. Since the resin film has a crosslinked structure, it has the strongest wear resistance among the layers of the photoreceptor. Further, since a curable charge transport material is blended, the charge transport property is similar to that of the charge transport layer.
It is important that the cross-linked resin surface layer contains at least a trimethylolpropane triacrylate cross-linked product, a cured organosilica film, and a cross-linked product of a heat or photo-curable charge transport material. In the present invention, the state in which the organosilica is mixed is important, and the blending ratio is such that the organosilica substantially functions as 10 wt% or more and less than 90 wt% with respect to the total solid weight of the cross-linked resin surface layer. Good.

Further, it may be cured together with caprolactone-modified dipentaerythritol hexaacrylate or dipentaerythritol hexaacrylate. This often improves the wear resistance of the crosslinked film itself or increases the toughness.
Trimethylolpropane triacrylate, caprolactone-modified dipentaerythritol hexaacrylate, and dipentaerythritol hexaacrylate can be obtained from reagent manufacturers such as Tokyo Kasei Co., Ltd., Nippon Kayaku Co., Ltd. KAYARD DPCA series, and DPHA series.
An initiator such as 1-hydroxycyclohexyl phenyl ketone (for example, Ciba Specialty Chemicals Irgacure 184) may be added to this at about 5 to 10 wt% based on the total solid content.

In the present invention, inclusion of a cured organosilica film in the cross-linked resin surface layer is important for achieving the object. A cured organosilica film, for example, is produced by hydrolyzing a polyfunctional alkoxysilane such as methyltriethoxysilane through moisture in the atmosphere or the like, and further, by repeating dehydration condensation reaction between these silanols, the cured film is formed. It is formed. In order to contain such a cured organosilica film in the crosslinkable resin surface layer, a compound having an alkoxysilyl group, a partially hydrolyzed condensate thereof, or a mixture thereof is used as a main component, and if necessary, a catalyst, a crosslinker It is realized by applying a composition in which a polymer such as an organosilica sol or a silane coupling agent is added to a photocurable paint such as trimethylolpropane triacrylate, and then thermally curing. The heat curing at this time uses heat generated during photocuring. The cross-linked surface layer is not bonded by a chemical bond between the photo-curing resin and the thermosetting resin, and exists in a form in which they are individually mixed.
As the compound containing an alkoxysilyl group, one or more of a tetraalkoxysilane such as tetraethoxysilane, an alkyltrialkoxysilane such as methyltriethoxysilane, and an aryltrialkoxysilane such as phenyltriethoxysilane are appropriately selected and used. . A partially hydrolyzed condensate of a compound containing an alkoxysilyl group can be produced by a known method in which a predetermined amount of water, a catalyst or the like is added to the compound containing an alkoxysilyl group and reacted.

  As a raw material for forming a cured organosilica film, it is also preferable to use a commercially available coating agent. Specifically, GR-COAT (made by Daicel Chemical Industries), GlassResin (made by Owen Corning), heat MKC silicate (Mitsubishi) is made by copolymerizing acrylic resin or polyester resin with Lesgrass (Ohashi Chemical Industries), NSC (Nippon Seika), glass stock solution GO150SX, GO200CL (Fineglass Technology), alkoxysilyl compound. Chemical), silicate / acrylic varnish XP-1030-1 (Dainippon Color Material Industries) and the like.

The curable charge transporting material is preferably a material that is excellent in injectability from the underlying charge transporting layer and has a high charge transporting ability. On the other hand, the use of a charge transporting monomer used for the synthesis of a polymer charge transporting material exemplified in JP-A-2001-330973 has a high track record and is extremely useful. In addition, if the amount of substance (equivalent) per functional group responsible for curing the molecular skeleton is small, the content of the curing agent (partner) in the curable resin surface layer is increased, resulting in a charge that can be cured. Limits the maximum content of transport materials. In terms of formulation design, a material having a large equivalent weight is preferable. Specifically, a material having an equivalent weight of 200 or more may be selected. In particular, it can be said that the use of the compounds represented by the general formulas 1 to 3 described above is reasonable.
As an example of a more preferable compound in the present invention, for the general formula 1, acrylic acid 4 '-(di-p-tolylamino) -biphenyl-4-yl-ester, 2-methyl-acrylic acid 4'- (Di-p-tolylamino) -biphenyl-4-yl-ester, acrylic acid 4'-diphenylamino-biphenyl-4-yl-ester, 2-methyl-acrylic acid 4'-diphenylamino-biphenyl-4-yl- Esters are preferred.
Similarly, for general formula 2, (4- [bis- (4-methoxyphenyl) -methyl] -diphenyl-amine, (4- [bis- (4-ethoxyphenyl) -methyl] -diphenyl-amine, (4- [Bis- (4-methoxyphenyl) -methyl] -di-p-tolyl-amine and (4- [bis- (4-ethoxyphenyl) -methyl] -di-p-tolyl-amine are preferred.
For general formula 3, 4 '-[(di-p-tolyl-amino) -biphenyl-4-yl-oxy] -methanol, 4'-[(di-p-tolyl-amino) -biphenyl -4-yl-oxy] -ethanol is preferred.
The radical polymerization of the coating film is easy to expose with a metal halide lamp. The charge transport material of the general formula 1 has little useless light absorption that inhibits radical polymerization during this exposure. This is advantageous for uniform film formation. Since it is important to express the charge transport function substantially by blending this material, the content thereof is required to be 5 wt% or more with respect to the total solid content weight of the cross-linked resin surface layer. The upper limit is preferably less than 60 wt% for the purpose of suppressing cost and film strength deterioration.

（式中Ｒ₁はアルキル基を表す。） The crosslinkable resin surface layer coating solution is obtained by dispersing at least trimethylolpropane triacrylate, organosilica, a heat or photocurable charge transport material in a solvent. The dispersion solvent used in preparing the cross-linked resin surface layer coating solution is preferably a solvent that sufficiently dissolves the monomer, such as ethoxyethanol in addition to the ethers, aromatics, halogens, esters described above. Examples thereof include cellosolves and propylene glycols such as 1-alkoxy-2-propanol represented by the following general formula 4. Among these, methyl ethyl ketone, tetrahydrofuran, cyclohexanone, and 1-methoxy-2-propanol are preferable because they have a lower environmental impact than chlorobenzene, dichloromethane, toluene, and xylene. These solvents can be used alone or in combination.

(In the formula, R ₁ represents an alkyl group.)

  Examples of the coating of the crosslinkable resin surface layer coating include dipping, spray coating, ring coating, roll coater, gravure coating, nozzle coating, and screen printing. In many cases, since the pot life of the coating liquid is not long, a means capable of coating a necessary amount with a small amount of paint is advantageous in consideration of the environment and cost. Of these, the spray coating method and the ring coating method are preferred.

When forming the cross-linked resin surface layer, a UV irradiation light source such as a high-pressure mercury lamp or a metal halide lamp having an emission wavelength mainly in ultraviolet light can be used. In addition, a visible light source can be selected in accordance with the absorption wavelength of the radical polymerizable substance or the photopolymerization initiator. Irradiation light amount is 50 mW / cm ² or more, preferably 1000 mW / cm ² or less, it takes time for the curing reaction is less than 50 mW / cm ^2. If it is higher than 1000 mW / cm ^2, the progress of the reaction becomes non-uniform, and local flaws are generated on the surface of the cross-linked charge transport layer, or many unreacted residues and reaction termination ends are generated. In addition, internal stress increases due to rapid crosslinking, which causes cracks and film peeling.
If the curing temperature is too high or too low, curing failure will occur, so this setting will affect the stabilization of quality. In order to proceed with sufficient curing, it is better to avoid sudden volatilization of the solvent. On the other hand, if the curing rate is too slow, the film thickness unevenness or cracks of the curable resin surface layer itself and the alteration of the base such as the crystallization of the charge transport material need to be heated.
Although it is necessary to adjust the specific set temperature depending on the material to be used, it is usually preferable to heat at a temperature slightly higher than the boiling point of the coating solvent used in the coating liquid for the curable resin surface layer. Usually, it is good to heat dry at about 130 ° C. ± 20 ° C. for about 30 minutes. If the temperature is higher than this, the photosensitive layer may be damaged, and if the temperature is lower than this, the paint solvent may remain.

If necessary, low-molecular compounds and leveling agents such as antioxidants, plasticizers, lubricants, and UV absorbers described in the charge generation layer and polymer compounds described in the charge transport layer are added to the cross-linked resin surface layer. You can also. These compounds can be used alone or as a mixture of two or more. When a low molecular weight compound and a leveling agent are used in combination, sensitivity deterioration often occurs. For this reason, the amount used is generally 0.1 to 20 wt%, preferably 0.1 to 10 wt%, and the leveling agent used is about 0.1 to 5 wt% in the total solid content of the paint.
The thickness of the cross-linked resin surface layer is suitably about 3 to 15 μm. The lower limit is a value calculated from the degree of effect on the film forming cost, and the upper limit is set from electrostatic characteristics such as charging stability and light attenuation sensitivity, and uniformity of film quality.
Examples of the leveling agent used in the present invention include dimethyl silicone oil, methylphenyl silicone oil, alkyl-modified silicone, alkoxy-modified silicone, and polyether-modified silicone. Specific examples include KF-50-100CS (methyl phenyl silicone oil) marketed by Shin-Etsu Chemical Co., Ltd. and SH200 (dimethyl silicone oil) manufactured by Toray Dow Corning. Those having an acryloyl group can be particularly advantageously used in the present invention. For example, the use of BYK-UV3570 (a mixture of acrylic group-containing polyester-modified polydimethylsiloxane and propoxy-modified-2-neopentylglycol diacrylate) marketed by Big Chemie is excellent in coating film smoothness and less harmful As advantageous.

  Japanese Laid-Open Patent Publication No. 2006-010963 discloses a technique of using both thermosetting and photocuring in the process of forming a cross-linked resin film on the surface of an electrophotographic photoreceptor. As described in [0025] of this document, this measure improves the uniformity of the curing of the cross-linked resin surface layer by using a photopolymerization initiator and a thermal polymerization initiator, and the carbon-carbon double bond at the unreacted site. It is recognized that the prevention of oxidizing gas adsorption to the part and the suppression of wrinkles and cracks are obtained. Although the subject matter and the configuration are different from those of the present invention, the effects disclosed in this document are considered to be partially enjoyed in the present invention.

  In JP-A-2005-077947, SUPER BEKKAMINE G-821-60 (melamine) manufactured by Dainippon Ink & Chemicals, Inc. and Sumijour HT (hdi-based isocyanate and trimethylolpropane adducts manufactured by Sumitomo Bayer Urethane Co., Ltd.) are disclosed. ) With a radically polymerizable monomer has an effect of improving cracking and peeling of the crosslinked film.

  The factor effect on the mechanical strength improvement of the cross-linked film often depends on the sum of chemical bond energies and cross-link density, and this factor is specifically related to the type of material. The composition of the material is different between this application and this patent document, and it seems that the same effect is not necessarily obtained. However, the effect (crack and film peeling) expressed by mixing a thermosetting material and a photocurable material. Prevention) would also be enjoyed.

In the present invention, an antioxidant, a plasticizer, an ultraviolet absorber, a low molecular charge transporting material, and a leveling agent can be added to each layer in order to improve the gas barrier property and environmental resistance of each layer of the photoreceptor.
Representative materials of these compounds are described below.
Examples of the antioxidant that can be added to each layer include, but are not limited to, the following (a) to (d).

(A) Phenol-based antioxidant 2,6-di-t-butyl-p-cresol, 2,4,6-tri-t-butylphenol, n-octadecyl-3- (4'-hydroxy-3 ', 5 '-Di-t-butylphenol) propionate, styrenated phenol, 4-hydroxymethyl-2,6-di-t-butylphenol, 2,5-di-t-butylhydroquinone, cyclohexylphenol, butylhydroxyanisole, 2,2 '-Methylene-bis (4-ethyl-6-tert-butylphenol), 4,4'-i-propylidenebisphenol, 1,1-bis (4-hydroxyphenyl) cyclohexane, 4,4'-methylene-bis ( 2,6-di-t-butylphenol), 2,6-bis (2'-hydroxy-3'-t-butyl-5'-methylbenzi) ) -4-methylphenol, 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 1,3,5-trismethyl-2,4,6-tris (3 , 5-di-t-butyl-4-hydroxybenzyl) benzene, tetrakis [methylene-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] methane, tris (3,5-di-) t-butyl-4-hydroxyphenyl) isocyanate, tris [β- (3,5-di-t-butyl-4-hydroxyphenyl) propionyl-oxyethyl] isocyanate, 4,4′-thiobis (3-methyl-6- t-butylphenol), 2,2'-thiobis (4-methyl-6-t-butylphenol), 4,4'-thiobis (4-methyl-6-t-butylphenol)

(B) Amine-based antioxidants phenyl-α-naphthylamine, phenyl-β-naphthylamine, N, N′-diphenyl-p-phenylenediamine, N, N′-di-β-naphthyl-p-phenylenediamine, N— Cyclohexyl-N′-phenyl-p-phenylenediamine, N-phenylene-N′-i-propyl-p-phenylenediamine, aldol-α-naphthylamine, 6-ethoxy-2,2,4-trimethyl-1,2- Dihydroquinoline

(C) Sulfur-based antioxidants thiobis (β-naphthol), thiobis (N-phenyl-β-naphthylamine), 2-mercaptobenzothiazole, 2-mercaptobenzimidazole, dodecyl mercaptan, tetramethylthiuram monosulfide, tetramethylthiuram Disulfide, nickel dibutyl thiocarbamate, isopropyl xanthate, dilauryl thiodipropionate, distearyl thiodipropionate

(D) Phosphorous antioxidant triphenyl phosphite, diphenyl decyl phosphite, phenyl isodecyl phosphite, tri (nonylphenyl) phosphite, 4,4'-butylidene-bis (3-methyl-6-t-butyl) Phenyl-ditridecyl phosphite), distearyl-pentaerythritol diphosphite, trilauryl trithiophosphite

Examples of the plasticizer that can be added to each layer include, but are not limited to, the following (a) to (m).
(A) Phosphate ester plasticizer Triphenyl phosphate, tricresyl phosphate, trioctyl phosphate, octyl diphenyl phosphate, trichloroethyl phosphate, cresyl diphenyl phosphate, tributyl phosphate, tri-2-ethylhexyl phosphate, Triphenyl phosphate etc.
(B) Phthalate ester plasticizers Dimethyl phthalate, diethyl phthalate, diisobutyl phthalate, dibutyl phthalate, diheptyl phthalate, di-2-ethylhexyl phthalate, diisooctyl phthalate, di-n-octyl phthalate, phthalate Dinonyl acid, diisononyl phthalate, diisodecyl phthalate, diundecyl phthalate, ditridecyl phthalate, dicyclohexyl phthalate, butyl benzyl phthalate, butyl lauryl phthalate, methyl oleyl phthalate, octyl decyl phthalate, dibutyl fumarate, dioctyl fumarate Such.

(C) Aromatic carboxylic acid ester plasticizers Trioctyl trimellitic acid, tri-n-octyl trimellitic acid, octyl oxybenzoate, and the like.
(D) Aliphatic dibasic ester plasticizer dibutyl adipate, di-n-hexyl adipate, di-2-ethylhexyl adipate, di-n-octyl adipate, adipic acid n-octyl-n-decyl Diisodecyl adipate, dicapryl adipate, di-2-ethylhexyl azelate, dimethyl sebacate, diethyl sebacate, dibutyl sebacate, di-n-octyl sebacate, di-2-ethylhexyl sebacate, di-2 sebacate -Ethoxyethyl, dioctyl succinate, diisodecyl succinate, dioctyl tetrahydrophthalate, di-n-octyl tetrahydrophthalate and the like.
(E) Fatty acid ester derivatives butyl oleate, glycerin monooleate, methyl acetylricinoleate, pentaerythritol ester, dipentaerythritol hexaester, triacetin, tributyrin and the like.

(F) Oxyacid ester plasticizers Methyl acetyl ricinoleate, butyl acetyl ricinoleate, butyl phthalyl butyl glycolate, tributyl acetyl citrate and the like.
(G) Epoxy plasticizer Epoxidized soybean oil, epoxidized linseed oil, butyl epoxy stearate, decyl epoxy stearate, octyl epoxy stearate, benzyl epoxy stearate, dioctyl epoxy hexahydrophthalate, didecyl epoxy hexahydrophthalate, etc. .
(H) Dihydric alcohol ester plasticizers such as diethylene glycol dibenzoate and triethylene glycol di-2-ethylbutyrate.
(I) Chlorinated plasticizer Chlorinated paraffin, chlorinated diphenyl, chlorinated fatty acid methyl, methoxychlorinated fatty acid methyl and the like.
(J) Polyester plasticizer Polypropylene adipate, polypropylene sebacate, polyester, acetylated polyester and the like.

(K) Sulfonic acid derivatives p-toluenesulfonamide, o-toluenesulfonamide, p-toluenesulfoneethylamide, o-toluenesulfoneethylamide, toluenesulfone-N-ethylamide, p-toluenesulfone-N-cyclohexylamide and the like.
(L) Citric acid derivatives Triethyl citrate, triethyl acetylcitrate, tributyl citrate, tributyl acetylcitrate, tri-2-ethylhexyl acetylcitrate, acetylcitrate-n-octyldecyl, and the like.
(M) Others Terphenyl, partially hydrogenated terphenyl, camphor, 2-nitrodiphenyl, dinonylnaphthalene, methyl abietate and the like.

Examples of the ultraviolet absorber that can be added to each layer include, but are not limited to, the following (a) to (f).
(A) Benzophenone series 2-hydroxybenzophenone, 2,4-dihydroxybenzophenone, 2,2 ', 4-trihydroxybenzophenone, 2,2', 4,4'-tetrahydroxybenzophenone, 2,2'-dihydroxy-4 -Methoxybenzophenone and the like.
(B) Salsylate type Phenyl salsylate, 2,4-di-t-butylphenyl-3,5-di-t-butyl-4-hydroxybenzoate, and the like.

(C) Benzotriazole-based (2'-hydroxyphenyl) benzotriazole, (2'-hydroxy-5'-methylphenyl) benzotriazole, (2'-hydroxy-3'-t-butyl-5'-methylphenyl) -5-chlorobenzotriazole and the like.
(D) Cyanoacrylate-based ethyl-2-cyano-3,3-diphenyl acrylate, methyl-2-carbomethoxy-3- (paramethoxy) acrylate, and the like.

(E) Quencher (metal complex)
Nickel [2,2′-thiobis (4-t-octyl) phenolate] normal butylamine, nickel dibutyldithiocarbamate, cobalt dicyclohexyldithiophosphate, and the like.
(F) HALS (hindered amine)
Bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, 1- [2- [3- (3 5-di-t-butyl-4-hydroxyphenyl) propionyloxy] ethyl] -4- [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyloxy] -2,2,6 6-tetramethylpyridine, 8-benzyl-7,7,9,9-tetramethyl-3-octyl-1,3,8-triazaspiro [4,5] undecane-2,4-dione, 4-benzoyloxy- 2,2,6,6-tetramethylpiperidine and the like.

  As the low molecular charge transport material that can be added to each layer, the same materials as those described in the description of the charge generation layer 25 can be used.

The electrophotographic apparatus used in the present invention will be described below with reference to the drawings.
FIG. 1 is a schematic view for explaining an electrophotographic apparatus of the present invention, and modifications as will be described later also belong to the category of the present invention.
In FIG. 1, a photoreceptor 11 is an electrophotographic photoreceptor in which a cross-linked resin surface layer is laminated. The photoconductor 11 has a drum shape, but may have a sheet shape or an endless belt shape.
As the charging means 12, known means such as a corotron, a scorotron, a solid state charger (solid state charger), and a charging roller are used. As the charging unit, one that is in contact with or close to the photosensitive member is preferably used from the viewpoint of reducing power consumption. In particular, in order to prevent contamination of the charging unit, a charging mechanism disposed in the vicinity of the photosensitive member having an appropriate gap between the surface of the photosensitive member and the charging unit is desirable. As the transfer means 16, the above charger can be generally used, but a combination of a transfer charger and a separation charger is effective.

Examples of the light source used for the exposure unit 13 and the charge removal unit 1A include fluorescent lamps, tungsten lamps, halogen lamps, mercury lamps, sodium lamps, light emitting diodes (LEDs), semiconductor lasers (LDs), electroluminescences (ELs) and the like. General. Various types of filters such as a sharp cut filter, a band pass filter, a near infrared cut filter, a dichroic filter, an interference filter, and a color temperature conversion filter can be used to irradiate only light in a desired wavelength range.
The toner 15 developed on the photosensitive member by the developing unit 14 is transferred to a printing medium 18 such as printing paper or an OHP slide, but not all is transferred, and toner remaining on the photosensitive member is also generated. . Such toner is removed from the photoreceptor by the cleaning means 17. As the cleaning means, a rubber cleaning blade, a brush such as a fur brush, a mag fur brush, or the like can be used.

  When a positive (negative) charge is applied to the electrophotographic photosensitive member and image exposure is performed, a positive (negative) electrostatic latent image is formed on the surface of the photosensitive member. When this is developed with negative (positive) polarity toner (electrodetection fine particles), a positive image can be obtained, and when developed with positive (negative) polarity toner, a negative image can be obtained. A known method is applied to the developing unit, and a known method is also used for the charge eliminating unit.

FIG. 2 shows another example of an electrophotographic process according to the present invention. In FIG. 2, a photoreceptor 11 is an electrophotographic photoreceptor in which a cross-linked resin surface layer is laminated. Although the photoconductor 11 has a belt shape, it may be a drum, a sheet, or an endless belt. The photosensitive member 11 is driven by the driving unit 1C, charged by the charging unit 12, image exposure by the exposure unit 13, development (not shown), transfer by the transfer unit 16, exposure before cleaning by the pre-cleaning exposure unit 1B, and cleaning unit 17. Cleaning and neutralization by the neutralization means 1A are repeated. In FIG. 12, light irradiation for pre-cleaning exposure is performed from the support side of the photoreceptor (in this case, the support is translucent).
The above electrophotographic process exemplifies an embodiment of the present invention, and other embodiments are of course possible. For example, in FIG. 2, the pre-cleaning exposure is performed from the support side, but this may be performed from the photosensitive layer side, or image exposure and neutralization light irradiation may be performed from the support side. On the other hand, the light irradiation process is illustrated as image exposure, pre-cleaning exposure, and static elimination exposure. In addition, a pre-transfer exposure, a pre-exposure of image exposure, and other known light irradiation processes are provided to light the photosensitive member. Irradiation can also be performed.
Further, the image forming means as described above may be fixedly incorporated in a copying machine, a facsimile, or a printer, but may be incorporated in these apparatuses in the form of a process cartridge. There are many types of process cartridges, but a typical example is shown in FIG. The photoconductor 11 has a drum shape, but may have a sheet shape or an endless belt shape.

  FIG. 4 shows another example of the electrophotographic apparatus according to the present invention. In this electrophotographic apparatus, a developing unit 14Bk and 14C for each color toner of the charging unit 12, the exposure unit 13, black (Bk), cyan (C), magenta (M), and yellow (Y) around the photoconductor 11 is provided. , 14M, 14Y, an intermediate transfer belt 1F as an intermediate transfer member, and a cleaning unit 17 are arranged in this order. Here, the subscripts Bk, C, M, and Y shown in the figure correspond to the color of the toner, and are added or omitted as appropriate. The photoreceptor 11 is an electrophotographic photoreceptor on which a cross-linked resin surface layer is laminated. Each color developing means 14Bk, 14C, 14M, 14Y can be controlled independently, and only the color developing means for image formation is driven. The toner image formed on the photoconductor 11 is transferred onto the intermediate transfer belt 1F by the first transfer unit 1D disposed inside the intermediate transfer belt 1F. The first transfer unit 1D is disposed so as to be able to come into contact with and separate from the photoconductor 11, and the intermediate transfer belt 1F is brought into contact with the photoconductor 11 only during the transfer operation. The respective color images are sequentially formed, and the toner images superimposed on the intermediate transfer belt 1F are collectively transferred to the print medium 18 by the second transfer unit 1E, and then fixed by the fixing unit 19 to form an image. . The second transfer means 1E is also arranged so as to be able to contact and separate from the intermediate transfer belt 1F, and contacts the intermediate transfer belt 1F only during the transfer operation.

  In the transfer drum type electrophotographic apparatus, since the toner images of the respective colors are sequentially transferred onto the transfer material electrostatically attracted to the transfer drum, there is a limitation on the transfer material that cannot be printed on cardboard, as shown in FIG. Such an intermediate transfer type electrophotographic apparatus has an advantage that the toner images of the respective colors are superimposed on the intermediate transfer body 1F, and thus are not limited by the transfer material. Such an intermediate transfer method is not limited to the apparatus shown in FIG. 4, but can be applied to the electrophotographic apparatus shown in FIGS. 1, 2, and 3 and FIG. 5 (a specific example is shown in FIG. 6) described later. it can.

  FIG. 5 shows another example of the electrophotographic apparatus according to the present invention. This electrophotographic apparatus is of a type that uses four colors of yellow (Y), magenta (M), cyan (C), and black (Bk) as toner, and an image forming unit is provided for each color. In addition, photoconductors 11Y, 11M, 11C, and 11Bk for each color are provided. The photoreceptor 11 used in this electrophotographic apparatus is an electrophotographic photoreceptor in which a crosslinkable resin surface layer is laminated. Around each of the photoconductors 11Y, 11M, 11C, and 11Bk, a charging unit 12, an exposure unit 13, a developing unit 14, a cleaning unit 17, and the like are disposed. Further, a transfer transfer belt 1G as a transfer material carrier that is brought into contact with and separated from each transfer position of each of the photoconductors 11Y, 11M, 11C, and 11Bk arranged on a straight line is stretched by a driving unit 1C. A transfer unit 16 is disposed at a transfer position facing each of the photoreceptors 1Y, 1M, 1C, and 1Bk with the conveyance transfer belt 1G interposed therebetween.

  The tandem type electrophotographic apparatus as shown in FIG. 5 has the photoreceptors 1Y, 1M, 1C, and 1Bk for each color, and sequentially transfers the toner images of the respective colors to the print medium 18 held on the conveyance transfer belt 1G. Therefore, it is possible to output a full-color image much faster than a full-color electrophotographic apparatus having only one photoconductor.

Hereinafter, the present invention will be described by way of examples. First, the measurement method according to the present invention will be described.
(1) Surface Roughness Measurement The surface of a drum-shaped photoconductor is measured with a stylus type surface roughness meter Surfcom (manufactured by Tokyo Seimitsu Co., Ltd.) with a pickup E-DT-S02A manufactured by Tokyo Seimitsu Co., Ltd. The maximum height Rmax (JIS B0601; 1982) at two points 10 cm apart was measured. The average value of the three locations was taken as the maximum height of the photoreceptor.

(2) Film thickness measurement Using an eddy current method film thickness measuring instrument (FISCHER SCOPE mms, manufactured by Fischer), the film thickness was measured at intervals of 1 cm in the longitudinal direction of the photosensitive drum, and the average value thereof was taken as the photosensitive layer thickness.

Example 1
On an aluminum drum having a wall thickness of 0.8 mm, a length of 340 mm, and an outer diameter of 30 mm, an undercoat layer coating solution, a charge generation layer coating solution, and a charge transport layer coating solution are sequentially applied and dried. As a result, an undercoat layer of 3.5 μm, a charge generation layer of 0.2 μm, and a charge transport layer of 22 μm were formed. A cross-linked resin surface layer coating solution having the following composition was applied thereon by spraying, and UV curing was performed while rotating the drum at a distance of 120 mm from this drum and a UV curing lamp. The illuminance of the UV curing lamp at this position was 600 mW / cm ² (ultraviolet integrated light meter UIT-150, measured value by Ushio Inc.). The drum rotation speed was 25 rpm. When performing UV curing, a rod-shaped metal block was included in an aluminum drum. In UV curing, exposure was performed for 6 minutes in total by repeating exposure for 30 seconds and pause for 120 seconds. After UV curing, it was dried by heating at 130 ° C. for 30 minutes. As a result, a 15 μm cross-linked resin surface layer was provided to obtain an electrophotographic photosensitive member.

[Coating liquid for undercoat layer]
Alkyd resin solution (Beckolite M6401-50, manufactured by Dainippon Ink and Chemicals) 12 parts by weight Melamine resin solution (Super Becamine G-821-60, manufactured by Dainippon Ink and Chemicals) 8 parts by weight Titanium oxide (CR- EL Ishihara Sangyo Co., Ltd.) 40 parts by weight methyl ethyl ketone 200 parts by weight

ポリビニルブチラール（ＸＹＨＬ、ＵＣＣ社製） １重量部
シクロヘキサノン ２００重量部
メチルエチルケトン ８０重量部 [Coating liquid for charge generation layer]
5 parts by weight of bisazo pigment having the following structure (manufactured by Ricoh)

Polyvinyl butyral (XYHL, manufactured by UCC) 1 part by weight Cyclohexanone 200 parts by weight Methyl ethyl ketone 80 parts by weight

テトラヒドロフラン １００重量部
１％シリコーンオイル（ＫＦ５０−１００ＣＳ、信越化学工業社製）テトラヒドロフラン溶液 １重量部 [Coating liquid for charge transport layer]
Z-type polycarbonate (Panlite TS-2050, manufactured by Teijin Chemicals Ltd.) 10 parts by weight 9 parts by weight of low molecular charge transport material having the following structure

Tetrahydrofuran 100 parts by weight 1% silicone oil (KF50-100CS, manufactured by Shin-Etsu Chemical Co., Ltd.) Tetrahydrofuran solution 1 part by weight

トリメチロールプロパントリアクリレート
（ＫＡＹＡＲＡＤ ＴＭＰＴＡ、日本化薬社製） ５０重量部
アクリル基含有ポリエステル変性ポリジメチルシロキサンとプロポキシ変性−２−ネオ
ペンチルグリコールジアクリレート混合物
（ＢＹＫ−ＵＶ３５７０、ビックケミー社製） ０．１重量部
１−ヒドロキシシクロヘキシルフェニルケトン
（イルガキュア１８４、チバ・スペシャリティ・ケミカルズ社製） ５重量部
オルガノシリカ（日本精化工業社製 ＮＳＣ２３１９固形分） ２０．０重量部
テトラヒドロフラン ４００重量部
プロピレングリコールモノメチルエーテル １６６重量部 [Crosslinked resin surface layer coating solution]
50 parts by weight of a cross-linked charge transport material having the following structure

Trimethylolpropane triacrylate (KAYARAD TMPTA, Nippon Kayaku Co., Ltd.) 50 parts by weight Mixture of acrylic group-containing polyester-modified polydimethylsiloxane and propoxy-modified-2-neopentylglycol diacrylate (BYK-UV3570, manufactured by BYK Chemie) 0.1 1 part by weight 1-hydroxycyclohexyl phenyl ketone (Irgacure 184, manufactured by Ciba Specialty Chemicals) 5 parts by weight Organosilica (NSC 2319 solids by Nippon Seika Kogyo Co., Ltd.) 20.0 parts by weight Tetrahydrofuran 400 parts by weight Propylene glycol monomethyl ether 166 Parts by weight

After the electrophotographic photosensitive member of Example 1 manufactured as described above was used for mounting, it was mounted on an electrophotographic apparatus (IPSiO Color 8100, manufactured by Ricoh Company), and in an 8 × 8 matrix with a pixel density of 600 dpi × 600 dpi. A total of 200,000 half-tone patterns each having 4 dots × 4 dots were printed on a copy paper (My Paper A4, NBS Ricoh Co., Ltd.) under the condition of printing 5 continuous sheets.
As the toner, cyan toner (polymerized toner to which silica powder was added) for Imagio Neo C455 was used. As a developer carrier, cyan developer for Imagio NeoC455 was used in each color developing station unit.
The photoconductor unit was a genuine product. As the applied voltage of the charging roller, a peak-to-peak voltage of 1.5 kV and a frequency of 0.9 kHz were selected as AC components. For the DC component, a bias was set so that the charged potential of the photosensitive member at the start of the test was −700 V, and the test was performed under this charging condition until the end of the test. The developing bias was −500V. In this apparatus, no neutralizing means is provided. The cleaning means was tested by changing a genuine product to an unused product every 50,000 printed sheets.

The test environment was 24 ° C./54% RH.
After the test, 10 halftone images having a pixel density of 600 dpi × 600 dpi and an image density of 5%, a blank image, and an image on which a fine line pattern was drawn were printed out in succession.
As a result, an image in which the outline of the dot image for drawing the halftone image slightly blurs was obtained. However, it is a level with no practical problem. The fine line pattern could identify a pair line for each dot.
Image noise due to poor cleaning was not shown in the output image, and there was no problem.
The photoconductor surface roughness (Rmax) at the end of the test was 0.4 μm at the maximum among the photoconductors attached to each developing station. It was almost smooth. Further, the amount of wear on the surface of the photoreceptor by the test was 10 μm.

Comparative Example 1
An electrophotographic photosensitive member was obtained in the same manner as in Example 1 except that the organosilica in the crosslinkable resin surface layer coating solution of Example 1 was removed. The same test was conducted.
As a result, an image in which the outline of the dot image for drawing the halftone image slightly blurs was obtained. However, it is a level with no practical problem. The fine line pattern could identify a pair line for each dot.
Linear image noise was caused by damage to the edge of the cleaning blade.
The photoconductor surface roughness (Rmax) at the end of the test was 2 μm at the maximum among the photoconductors attached to each developing station. Silica was stuck on the surface of the photoreceptor.

トリメチロールプロパントリアクリレート
（ＫＡＹＡＲＡＤ ＴＭＰＴＡ、日本化薬社製） １５重量部
アクリル基含有ポリエステル変性ポリジメチルシロキサンとプロポキシ変性−２−ネオ
ペンチルグリコールジアクリレート混合物
（ＢＹＫ−ＵＶ３５７０、ビックケミー社製） ０．１重量部
カプロラクトン変性ジペンタエリスリトールヘキサアクリレート
（ＫＡＹＡＲＤ ＤＰＣＡ−１２０、日本化薬社） １５重量部
１−ヒドロキシシクロヘキシルフェニルケトン
（イルガキュア１８４、チバ・スペシャリティ・ケミカルズ社製） ３重量部
オルガノシリカ（日本精化工業社製 ＮＳＣ１５００Ｎ固形分） ４０重量部
テトラヒドロフラン ４００重量部
プロピレングリコールモノメチルエーテル １６６重量部 Example 2
An electrophotographic photosensitive member was obtained in the same manner as in Example 1 except that the crosslinkable resin surface layer coating solution in Example 1 was changed to the following. The film thickness of the cross-linked resin surface layer was 3 μm.
[Crosslinked resin surface layer coating solution]
30 parts by weight of a cross-linked charge transport material having the following structure

Trimethylolpropane triacrylate (KAYARAD TMPTA, manufactured by Nippon Kayaku Co., Ltd.) 15 parts by weight Mixture of acrylic group-containing polyester-modified polydimethylsiloxane and propoxy-modified-2-neopentylglycol diacrylate (BYK-UV3570, manufactured by Big Chemie) 0.1 Parts by weight caprolactone-modified dipentaerythritol hexaacrylate (KAYARD DPCA-120, Nippon Kayaku) 15 parts by weight 1-hydroxycyclohexyl phenyl ketone (Irgacure 184, manufactured by Ciba Specialty Chemicals) 3 parts by weight organosilica NSC1500N solid content manufactured by Kogyo Co., Ltd.) 40 parts by weight Tetrahydrofuran 400 parts by weight Propylene glycol monomethyl ether 166 parts by weight

After the electrophotographic photosensitive member of Example 2 manufactured as described above was used for mounting, it was mounted on an electrophotographic apparatus (IPSiO Color 8100, manufactured by Ricoh Co., Ltd.) in a 8 × 8 matrix with a pixel density of 600 dpi × 600 dpi. On a copy paper (My Paper A4, manufactured by NBS Ricoh Co., Ltd.), a total of 20,000 sheets of halftone patterns having 4 dots × 4 dots were printed on a continuous 5 sheets. The test environment was 23 degreeC55% RH normal temperature normal humidity environment.
As the toner, a toner for Imagio Neo C455 was used. As a developer carrier, a developer for Imagio NeoC455 was used in each color developing station unit.
The photoconductor unit was a genuine product. As the applied voltage of the charging roller, a peak-to-peak voltage of 1.5 kV and a frequency of 0.9 kHz were selected as AC components. For the DC component, a bias was set so that the charged potential of the photosensitive member at the start of the test was −700 V, and the test was performed under this charging condition until the end of the test. The developing bias was −500V. In this apparatus, no static eliminating means is provided. The cleaning means was tested by changing a genuine product to an unused product every 50,000 printed sheets.
The test environment was 24 ° C./54% RH.

After the test, 10 halftone images having a pixel density of 600 dpi × 600 dpi and an image density of 5%, a blank image, and an image on which a fine line pattern was drawn were printed out in succession.
As a result, the outline of the dot image that draws the halftone image was clear. This is a level where there is no practical problem. The fine line pattern could identify a pair line for each dot.
Image noise due to poor cleaning was not shown in the output image, and there was no problem.
The photoconductor surface roughness (Rmax) at the end of the test was 0.3 μm at the maximum among the photoconductors attached to each developing station. It was almost smooth. Further, the amount of wear on the surface of the photoreceptor by the test was 1 μm.

Comparative Example 2
An electrophotographic photosensitive member was obtained in the same manner as in Example 2 except that the organosilica in the crosslinkable resin surface layer coating solution of Example 2 was removed. The same test was conducted.
As a result, an image with a clear outline of the dot image was obtained. This is a level where there is no practical problem. The fine line pattern could identify a pair line for each dot.
Linear image noise was caused by damage to the edge of the cleaning blade.
The photoconductor surface roughness (Rmax) at the end of the test was 0.5 μm at the maximum among the photoconductors attached to each developing station. A cross-sectional curve of the photoreceptor similar to that in FIG. 9 was obtained.

結果、ドット画像の輪郭が明瞭な画像が得られた。実用上問題のないレベルである。細線パターンは１ドット毎のペアラインが識別できた。
クリーニング不良による画像ノイズは出力画像に映し出されず問題なかった。
試験終了時の感光体表面粗さ（Ｒｍａｘ）は各現像ステーションに取り付けた感光体の内、最大で０．３μｍだった。ほぼ平滑だった。また、試験による感光体表面の摩耗量は１μｍだった。 Example 3
An electrophotographic photosensitive member was obtained in the same manner as in Example 2 except that the crosslinkable charge transport material in the crosslinkable resin surface layer coating solution of Example 2 was changed to the following. The same test was conducted.
30 parts by weight of a cross-linked charge transport material having the following structure

As a result, an image with a clear outline of the dot image was obtained. This is a level where there is no practical problem. The fine line pattern could identify a pair line for each dot.
Image noise due to poor cleaning was not shown in the output image, and there was no problem.
The photoconductor surface roughness (Rmax) at the end of the test was 0.3 μm at the maximum among the photoconductors attached to each developing station. It was almost smooth. Further, the amount of wear on the surface of the photoreceptor by the test was 1 μm.

Comparative Example 3
An electrophotographic photosensitive member was obtained in the same manner as in Example 2 except that the organosilica in the crosslinkable resin surface layer coating solution of Example 2 was changed to the following. The same test was conducted.
Melamine compound (Dai Nippon Ink Chemical Co., Ltd. Super Becamine G-821-60 solid content)
40 parts by weight As a result, an image with a clear outline of the dot image was obtained. This is a level where there is no practical problem. The fine line pattern could identify a pair line for each dot.
Linear image noise was caused by damage to the edge of the cleaning blade.
The photoconductor surface roughness (Rmax) at the end of the test was 1 μm at the maximum among the photoconductors attached to each developing station. In measuring the surface roughness of the photoreceptor, a cross-sectional curve similar to that in FIG. 9 was obtained. Further, the amount of wear on the surface of the photoreceptor by the test was 1.2 μm.

Example 4
On an aluminum drum having a wall thickness of 0.8 mm, a length of 340 mm, and an outer diameter of 30 mm, an undercoat layer coating solution, a charge generation layer coating solution, and a charge transport layer coating solution are sequentially applied and dried. As a result, an undercoat layer of 3.5 μm, a charge generation layer of 0.2 μm, and a charge transport layer of 22 μm were formed. A cross-linked resin surface layer coating solution having the following composition was applied thereon by spraying, and UV curing was performed while rotating the drum at a distance of 120 mm from this drum and a UV curing lamp. The illuminance of the UV curing lamp at this position was 600 mW / cm ² (ultraviolet integrated light meter UIT-150, measured value by Ushio Inc.). The drum rotation speed was 25 rpm. When performing UV curing, a rod-shaped metal block was included in an aluminum drum. In UV curing, exposure was performed for 4 minutes in total by repeating exposure for 30 seconds and rest for 120 seconds. After UV curing, it was dried by heating at 130 ° C. for 30 minutes. As a result, an 8 μm cross-linked resin surface layer was provided to obtain an electrophotographic photosensitive member.

[Coating liquid for undercoat layer]
Alkyd resin solution (Beckolite M6401-50, manufactured by Dainippon Ink & Chemicals, Inc.)
12 parts by weight Melamine resin solution (Super Becamine G-821-60, manufactured by Dainippon Ink & Chemicals, Inc.) 8 parts by weight Titanium oxide (CR-EL, manufactured by Ishihara Sangyo Co., Ltd.) 40 parts by weight Methyl ethyl ketone 200 parts by weight [for charge generation layer (Coating fluid)
Titanyl phthalocyanine (Ricoh Co., Ltd.) 20 parts by weight Polyvinyl alcohol (ESREC B BX-1, Sekisui Chemical Co., Ltd.) 10 parts by weight Methyl ethyl ketone 100 parts by weight

テトラヒドロフラン １００重量部
１％シリコーンオイル（ＫＦ５０−１００ＣＳ、信越化学工業社製）
テトラヒドロフラン溶液 １重量部 [Coating liquid for charge transport layer]
Z-type polycarbonate (Panlite TS-2050, manufactured by Teijin Chemicals Ltd.) 10 parts by weight 10 parts by weight of low molecular charge transport material having the following structure

Tetrahydrofuran 100 parts by weight 1% silicone oil (KF50-100CS, manufactured by Shin-Etsu Chemical Co., Ltd.)
1 part by weight of tetrahydrofuran solution

トリメチロールプロパントリアクリレート
（ＫＡＹＡＲＡＤ ＴＭＰＴＡ、日本化薬社製） ２５重量部
カプロラクトン変性ジペンタエリスリトールヘキサアクリレート
（ＫＡＹＡＲＤ ＤＰＣＡ−１２０、日本化薬社） ２５重量部
アクリル基含有ポリエステル変性ポリジメチルシロキサンとプロポキシ変性−２−ネオ
ペンチルグリコールジアクリレート混合物
（ＢＹＫ−ＵＶ３５７０、ビックケミー社製） ０．１重量部
１−ヒドロキシシクロヘキシルフェニルケトン
（イルガキュア１８４、チバ・スペシャリティ・ケミカルズ社製） ５重量部
オルガノシリカ（日本精化工業社製 ＮＳＣ２３１９固形分） ３０．０重量部
テトラヒドロフラン ４００重量部
プロピレングリコールモノメチルエーテル １６６重量部 [Crosslinked resin surface layer coating solution]
50 parts by weight of a cross-linked charge transport material having the following structure

Trimethylolpropane triacrylate (KAYARAD TMPTA, Nippon Kayaku) 25 parts by weight Caprolactone-modified dipentaerythritol hexaacrylate (KAYARD DPCA-120, Nippon Kayaku) 25 parts by weight Acrylic group-containing polyester-modified polydimethylsiloxane and propoxy-modified 2-Neopentyl glycol diacrylate mixture (BYK-UV3570, manufactured by Big Chemie) 0.1 part by weight 1-hydroxycyclohexyl phenyl ketone (Irgacure 184, manufactured by Ciba Specialty Chemicals) 5 parts by weight Organosilica (Nippon Seika) NSC2319 solid content manufactured by Kogyo Co., Ltd.) 30.0 parts by weight Tetrahydrofuran 400 parts by weight Propylene glycol monomethyl ether 166 parts by weight

After the electrophotographic photosensitive member of Example 4 produced as described above was used for mounting, it was mounted on an electrophotographic apparatus (IPSiO Color 8100, manufactured by Ricoh Co., Ltd.) in a matrix of 8 × 8 with a pixel density of 600 dpi × 600 dpi. A total of 60,000 halftone patterns each having 4 dots × 4 dots were printed on a copy paper (My Paper A4, NBS Ricoh Co., Ltd.) under the condition of printing 5 continuous sheets. The test environment was 23 degreeC55% RH normal temperature normal humidity environment.
As the toner, cyan toner for Imagio Neo C455 was used. As a developer carrier, cyan developer for Imagio NeoC455 was used in each color developing station unit.
The photoconductor unit was a genuine product. As the applied voltage of the charging roller, a peak-to-peak voltage of 1.5 kV and a frequency of 0.9 kHz were selected as AC components. For the DC component, a bias was set so that the charged potential of the photosensitive member at the start of the test was −700 V, and the test was performed under this charging condition until the end of the test. The developing bias was −500V. In this apparatus, no neutralizing means is provided. The cleaning means was tested by changing a genuine product to an unused product every 50,000 printed sheets.
The test environment was 25 ° C./55% RH.

After the test, 10 halftone images having a pixel density of 600 dpi × 600 dpi and an image density of 5%, a blank image, and an image on which a fine line pattern was drawn were printed out in succession.
As a result, an image in which the outline of the dot image for drawing the halftone image slightly blurs was obtained. However, it is a level with no practical problem. The fine line pattern could identify a pair line for each dot.
Image noise due to poor cleaning was not shown in the output image, and there was no problem.
The photoconductor surface roughness (Rmax) at the end of the test was 0.3 μm at the maximum among the photoconductors attached to each developing station. It was smooth. Further, the amount of wear on the surface of the photoreceptor by the test was 1.3 μm.

トリメチロールプロパントリアクリレート
（ＫＡＹＡＲＡＤ ＴＭＰＴＡ、日本化薬社製） ２５重量部
カプロラクトン変性ジペンタエリスリトールヘキサアクリレート
（ＫＡＹＡＲＤ ＤＰＣＡ−１２０、日本化薬社） ２５重量部
アクリル基含有ポリエステル変性ポリジメチルシロキサンとプロポキシ変性−２−ネオ
ペンチルグリコールジアクリレート混合物
（ＢＹＫ−ＵＶ３５７０、ビックケミー社製） ０．１重量部
１−ヒドロキシシクロヘキシルフェニルケトン
（イルガキュア１８４、チバ・スペシャリティ・ケミカルズ社製） ５重量部
オルガノシリカ（日本精化工業社製 ＮＳＣ２３１９固形分） ２０重量部
酸化スズ（三菱マテリアルズ社製 Ｓ−１） １０重量部
テトラヒドロフラン ４００重量部
プロピレングリコールモノメチルエーテル １６６重量部 Example 5
An electrophotographic photosensitive member was obtained in the same manner as in Example 4 except that the composition of the coating solution for the crosslinkable resin surface layer in Example 4 was as follows. The test was performed in the same manner as in Example 4.
[Crosslinked resin surface layer coating solution]
50 parts by weight of cross-linked charge transport material

Trimethylolpropane triacrylate (KAYARAD TMPTA, Nippon Kayaku) 25 parts by weight Caprolactone-modified dipentaerythritol hexaacrylate (KAYARD DPCA-120, Nippon Kayaku) 25 parts by weight Acrylic group-containing polyester-modified polydimethylsiloxane and propoxy-modified 2-Neopentyl glycol diacrylate mixture (BYK-UV3570, manufactured by Big Chemie) 0.1 part by weight 1-hydroxycyclohexyl phenyl ketone (Irgacure 184, manufactured by Ciba Specialty Chemicals) 5 parts by weight Organosilica (Nippon Seika) NSC2319 solid content manufactured by Kogyo Co., Ltd.) 20 parts by weight Tin oxide (S-1 manufactured by Mitsubishi Materials Corporation) 10 parts by weight Tetrahydrofuran 400 parts by weight Propylene glycol monomer Ether 166 parts by weight

As a result, an image in which the outline of the dot image for drawing the halftone image is somewhat blurred was obtained. However, although it is at a level where there is no practical problem, it cannot be said to be high quality. In the fine line pattern, a pair line every 4 dots could be identified. A pair line for each dot could not be identified.
Image noise due to poor cleaning was not shown in the output image, and there was no problem.
The photoconductor surface roughness (Rmax) at the end of the test was 0.4 μm at the maximum among the photoconductors attached to each developing station. It was smooth for the time being. Further, the amount of wear on the surface of the photoreceptor by the test was 1.0 μm.

Comparative Example 4
An electrophotographic photosensitive member was obtained in the same manner as in Example 4 except that the organosilica in the cross-linked resin surface layer coating solution of Example 4 was removed. The same test was conducted.
As a result, an image with a clear outline of the dot image was obtained. This is a level where there is no practical problem. The fine line pattern could identify a pair line for each dot.
Linear image noise was caused by damage to the edge of the cleaning blade.
The photoconductor surface roughness (Rmax) at the end of the test was 1.2 μm at the maximum among the photoconductors attached to each developing station. In measuring the surface roughness of the photoreceptor, a cross-sectional curve similar to that in FIG. 9 was obtained. Further, the amount of wear on the surface of the photoreceptor by the test was 2.4 μm.

1 is a schematic cross-sectional view illustrating an example of an electrophotographic apparatus according to the present invention. It is a schematic cross section which shows the other example of the electrophotographic apparatus which concerns on this invention. It is a schematic cross section showing an example of a process cartridge according to the present invention. It is a schematic cross section which shows the other example of the electrophotographic apparatus which concerns on this invention. It is a schematic cross section which shows the other example of the electrophotographic apparatus which concerns on this invention. It is a schematic cross section which shows the other example of the electrophotographic apparatus which concerns on this invention. It is sectional drawing which shows the layer structure of the electrophotographic photoreceptor which concerns on this invention. It is sectional drawing which shows another layer structure of the electrophotographic photoreceptor which concerns on this invention. It is an example of a photoreceptor cross-sectional curve obtained from surface roughness measurement.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Electrophotographic photoreceptor 12 ... Charging means 13 ... Exposure means 14 ... Developing means 15 ... Toner 16 ... Transfer means 17 ... Cleaning means 18 ... Print media ( Printing paper, OHP slide)
DESCRIPTION OF SYMBOLS 19 ... Fixing means 1A ... Static elimination means 1B ... Pre-cleaning exposure means 1C ... Driving means 1D ... First transfer means 1E ... Second transfer means 1F ... Intermediate transfer Body 21 ... conductive support 24 ... undercoat layer 25 ... charge generation layer 26 ... charge transport layer 28 ... crosslinked resin surface layer

Claims (11)

  An electrophotographic photoreceptor comprising a crosslinked resin surface layer of an electrophotographic photoreceptor containing a crosslinked product of trimethylolpropane triacrylate and a photocurable charge transport material and a cured organosilica film.   An electrophotographic photoreceptor comprising a crosslinked resin surface layer of an electrophotographic photoreceptor containing a crosslinked body of trimethylolpropane triacrylate and a crosslinked body of organosilica and a thermosetting charge transport material.   2. The electrophotographic photosensitive member according to claim 1, wherein the cross-linked resin surface layer of the electrophotographic photosensitive member is cured together with caprolactone-modified dipentaerythritol hexaacrylate or dipentaerythritol hexaacrylate. The cross-linked resin surface layer of the electrophotographic photosensitive member contains at least a cross-linked product of a photocurable charge transport material of the following general formula 1 in a proportion of 5 wt% or more and less than 60 wt%. 3. The electrophotographic photosensitive member according to 3.

(In General Formula 1, d, e, and f are each an integer of 0 or 1, R ₁₃ represents a hydrogen atom or a methyl group, and R ₁₄ and R ₁₅ are substituents other than a hydrogen atom and are alkyls having 1 to 6 carbon atoms. Represents a group and may be different in a plurality of cases, g and h each represent an integer of 0 to 3. Z represents a single bond, a methylene group or an ethylene group.

Represents. ) 4. The cross-linked resin surface layer of an electrophotographic photosensitive member contains at least a cross-linked product of a thermosetting charge transport material of the following general formula 2 or 3 in a proportion of 5 wt% or more and less than 60 wt%. 2. The electrophotographic photosensitive member according to 2.

{In General Formula 2, R ₂ and R ₃ and R ₄ represent a hydrogen atom, a substituted or unsubstituted alkyl group, or an aryl group. Ar ₁ and Ar ₂ represent an aryl group.
X represents any of the following (a) to ( c ).
(A) alkylene group (b) arylene group (c) group represented by the following general formula (5)

(Wherein, Y is -O -, - S -, - SO -, - SO2 -, - CO- and to display the divalent group below.

Here, p represents an integer of 1 to 12. )}

(In General Formula 3, R ₉ and R ₁₀ represent a substituted or unsubstituted aryl group. R ₉ and R ₁₀ may be the same or different. Ar ₆ and Ar ₇ represent an arylene group. , R ₉ and R ₁₀ may be the same divalent group as the aryl group, which may be the same or different.X is the same as X described in formula 2.)   6. The electrophotographic photosensitive member according to claim 1, wherein the content of the cured organosilica film contained in the cross-linked resin surface layer of the electrophotographic photosensitive member is 10 wt% or more and less than 90 wt%. body.   The electrophotographic photosensitive member according to claim 1, wherein the cross-linked resin surface layer of the electrophotographic photosensitive member contains no metal oxide fine particles. Coating containing a trimethylolpropane triacrylate, organosilica, and a heat or photocurable charge transport material on a photosensitive layer of an electrophotographic photoreceptor using a solvent containing at least a compound represented by the following general formula 4 By applying the solution, exposure and heating and drying, the coating film of this coating solution causes a crosslinking reaction, and the solvent is removed to form a crosslinked resin surface layer having a thickness of 3 μm or more and less than 15 μm. The method for producing an electrophotographic photosensitive member according to any one of claims 1 to 7.

(In general formula 4, R ₁ represents an alkyl group.)   A process cartridge comprising at least the electrophotographic photosensitive member according to claim 1.   An electrophotographic apparatus comprising the electrophotographic photosensitive member according to any one of claims 1 to 7 or the process cartridge according to claim 9.   The electrophotographic apparatus according to claim 10, wherein the electrophotographic apparatus has a developing station of at least two colors and is a tandem type and further develops using polymerized toner.

Images