JP4289142B2 - Electrophotographic photosensitive member, method for manufacturing the same, process cartridge, and image forming apparatus - Google Patents

Description

  The present invention relates to an electrophotographic photosensitive member and a method for manufacturing the same, and a process cartridge and an image forming apparatus using the electrophotographic photosensitive member.

  An electrophotographic photosensitive member is a member constituting the basic configuration of an image forming apparatus such as a printer, a copying machine, and a facsimile, and has been developed for the purpose of improving image quality. At present, the mainstream of electrophotographic photoreceptors (hereinafter sometimes referred to as “photoreceptors”) is function-separated organic photoreceptors. This photoreceptor includes a functional layer, and the functional layer has, for example, a configuration in which mainly a low molecular weight functional material is dispersed in a binder resin. In order for this functional layer to exhibit an excellent function in electrophotographic characteristics, how to uniformly disperse the functional material in the binder resin is an important technique.

  Among functional materials, especially charge generation materials are difficult to disperse uniformly in the binder resin due to their tendency to agglomerate. It has become a hindrance. Specifically, if the dispersibility of the charge generating material is poor, the sensitivity representing the potential decay during exposure is reduced, and the sensitivity varies among the photoconductors or lots, thereby reducing the image quality. In addition, a phenomenon called dark decay in which the potential is lowered even when not exposed is caused, and the image quality is deteriorated due to fogging or black spots.

  If the charge generating material is not uniformly dispersed in the binder resin, a desired charge generating function cannot be obtained unless the charge generating material is added excessively. On the other hand, when the charge generating material is added excessively, the heat resistance and mechanical strength of the functional layer are lowered, and problems such as deterioration of the heat resistance of the photoreceptor and generation of cracks occur.

In order to solve such problems, various studies have been made as follows. For example, a method of uniformly dispersing a phthalocyanine pigment having a charge generation function by using a butyral resin having a specific structure as a binder resin has been proposed (for example, see Patent Document 1). Further, a method for improving the dispersibility of a phthalocyanine pigment by using a binder resin having a styrene structure to adjust the acid value and reduce dark decay is known (see, for example, Patent Document 2). ). Furthermore, it is said that the dispersibility of the charge generation material is improved by using a binder resin that is soluble in an organic solvent in which lipids are combined with DNA (see, for example, Patent Document 3).
JP 2002-10792 A JP 2002-169308 A Japanese Patent Laid-Open No. 2002-251024

  However, in the methods described in Patent Documents 1 and 2 described above, since the dispersibility of the functional material such as the charge generation material is insufficient, sufficient heat resistance is caused by adding these excessively. And mechanical strength is not obtained. On the other hand, in the method using a DNA-lipid complex as a binder resin as described in Patent Document 3, dispersibility is improved as compared with the methods described in Patent Documents 1 and 2, but it is still insufficient. There is room for improvement. Further, when the DNA-lipid complex is used, there arises a problem that the mechanical strength of the electrophotographic photosensitive member becomes extremely low.

  The present invention has been made in view of such circumstances, and is excellent in heat resistance and mechanical strength, and can stably obtain a good image quality over a long period of time, and the electrophotographic photosensitive member. An object of the present invention is to provide an image forming apparatus and a process cartridge using the above.

  As a result of intensive studies to achieve the above object, the present inventors have found that the above object can be achieved by including a specific polymer in the functional layer, and have completed the present invention. .

That is, the electrophotographic photoreceptor of the present invention is characterized by including a charge generation layer containing DNA which is a water-soluble rod-like polymer.

According to the present invention, by providing the charge generation layer containing DNA which is a water-soluble rod-like polymer, the heat resistance and mechanical strength of the electrophotographic photosensitive member can be sufficiently increased, so that it is affected by heat and mechanical load. Deterioration of electrophotographic characteristics and generation of cracks can be prevented. Further, since the dispersibility of the conductive load generation materials can be sufficiently enhanced, thereby improving the electrophotographic characteristics due to the component. Therefore, according to the present invention, an electrophotographic photoreceptor capable of stably obtaining a good image quality for a long time is realized.

The reason why the above-described effect can be obtained by the present invention is not necessarily clear, but the present inventor presumes as follows. That is, since the DNA according to the present invention is water-soluble and has a rod-like rigid molecular structure, it can be regularly arranged while maintaining directionality in the charge generation layer. are those capable of sufficiently uniform dispersion of the charge generation materials. Therefore, it is considered that the heat resistance, mechanical strength and electrophotographic characteristics of the entire electrophotographic photosensitive member are improved by the effect of improving the heat resistance and mechanical strength of the DNA itself, and further the dispersibility. On the other hand, in the case of the DNA-lipid complex described in Patent Document 3, in addition to the lipid itself being inferior in heat resistance and mechanical strength, the regularity of the DNA sequence is disturbed by deformation of the lipid segment. Property and mechanical strength are reduced. Further, when a charge generating material or the like is dispersed in such a composite, dispersibility becomes insufficient, and any of heat resistance, mechanical strength, and electrophotographic characteristics can not be sufficiently improved.

  Here, the rod-like polymer referred to in the present invention refers to a polymer having a rod-like rigid molecular chain, and examples of the water-soluble rod-like polymer include biopolymers, liquid crystal polymers, and polyimide polymers. And polysaccharides. The functional layer refers to a layer for exhibiting a function useful for improving electrophotographic characteristics, and examples thereof include a charge generation layer, a charge transport layer, an undercoat layer, and a protective layer.

  Although the factors for obtaining such an effect are not necessarily clear, for example, in DNA or the like, a charge generating material or a charge transporting material is inserted in a gap between base pairs constituting a double helix structure regularly arranged in a predetermined direction. The present inventors infer that the dispersibility is improved because the part can intercalate.

The present invention also includes a step of preparing an object to be processed to be an electrophotographic photosensitive member by forming a charge generation layer containing DNA, which is a water-soluble rod-like polymer, and a step of preparing an aqueous solution containing DNA. And a step of forming a charge generation layer containing DNA by applying an aqueous solution onto the object to be processed and drying the electrophotographic photosensitive member.

According to the production method of the present invention, an electrophotographic photoreceptor excellent in heat resistance and mechanical strength can be easily obtained. In addition, since the DNA is water-soluble, it is not necessary to use an organic solvent, which is friendly to the global environment.

  The present invention further includes the above-described electrophotographic photosensitive member of the present invention, a charging device for charging the photosensitive member, an exposure device for exposing the charged photosensitive member to form an electrostatic latent image on the photosensitive member, and an electrostatic device. An image forming apparatus comprising: a developing device that develops a latent image to form a toner image on a photosensitive member; and a transfer device that transfers the toner image on the photosensitive member to a transfer medium; The electrophotographic photosensitive member of the present invention, a charging device for charging the photosensitive member, a developing device for developing an electrostatic latent image to form a toner image on the photosensitive member, and a toner remaining on the photosensitive member after the transfer process are removed. And at least one selected from a cleaning device to provide a process cartridge.

  According to the present invention, it is possible to provide an electrophotographic photoreceptor that is excellent in heat resistance and mechanical strength and can stably obtain a good image quality over a long period of time. Further, according to the image forming apparatus and the process cartridge using the electrophotographic photosensitive member, it is possible to stably obtain a good image quality over a long period of time.

  Preferred embodiments of the present invention will be described in detail. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and redundant description is omitted.

(Electrophotographic photoreceptor)
The electrophotographic photosensitive member of the present invention includes a functional layer containing a water-soluble rod-shaped polymer arranged in a predetermined direction.

  First, the rod-like polymer will be described. This rod-like polymer is water-soluble as described above, and rod-like rigid molecules are regularly arranged in a predetermined direction. Examples of such rod-like polymers include biopolymers, liquid crystal polymers, polyimide polymers, polysaccharides, and the like. Examples of the biopolymer include α-helix polypeptide, nucleic acid, and collagen. Examples of the nucleic acid include DNA, RNA, DNA / RNA hybrid and the like. Examples of polysaccharides include amylose, starch, and xanthan gum.

  Among these, the rod-like polymer is preferably an α-helix polypeptide having a regular helical structure, DNA, or amylose, and more preferably DNA. DNA is a unit gene that controls the genetic information of living organisms, and has a molecular structure in which two polynucleotide chains are spirally wound around one central axis. There are four types of nucleobases that are nucleotide group constituent molecules: adenine, thymine, guanine, and cytosine, and these form a Watson-Crick base pair. That is, thymine for adenine and cytosine for guanine specifically form hydrogen bonds to form base pairs. As a result, the two nucleotide chains constituting the DNA can be complementarily combined to form a double helix structure, and a void is created between adjacent base pairs. Therefore, even when the functional layer contains a charge generation material or a charge transport material, which will be described later, it is considered that one or more of these molecules can be intercalated into the voids of the helical structure, thereby improving dispersibility.

  The functional layer refers to a layer for exhibiting a function useful for improving electrophotographic characteristics as described above, and examples thereof include an undercoat layer, a charge generation layer, a charge transport layer, and a protective layer.

  The undercoat layer has a function of preventing the injection of charges from the conductive support to the charge generation layer during charging, and allows the charge generation layer to be integrally bonded and held to the conductive support. Also functions as an adhesive layer. Further, the undercoat layer also has a function of preventing light reflection of the conductive support.

  The charge generation layer has a function of generating charge carriers, and the charge transport layer has a function of moving carriers generated in the charge generation layer. The protective layer has a function of protecting the photosensitive layer.

  The rod-shaped polymer is preferably contained in at least one selected from an undercoat layer, a charge generation layer, a charge transport layer and a protective layer, and is preferably contained in the charge generation layer and / or the charge transport layer. More preferred.

  The aspect ratio of the rod-like polymer is preferably 50 to 7500, and more preferably 100 to 5000. The aspect ratio refers to the ratio (major axis / minor axis) between the major axis direction and the minor axis direction of the rod-like polymer. When the aspect ratio is less than 50, the rod-shaped polymer may not be regularly arranged, and when it exceeds 7500, the solubility in water may be deteriorated or the regular arrangement may be difficult.

  Further, even when the functional layer contains a small amount of rod-like polymer, the electrophotographic photoreceptor can have excellent heat resistance and mechanical strength, but the rod-like polymer contains 5% by mass or more. It is preferably 10% by mass or more. When the content of the rod-like polymer is less than 5% by mass, it may be difficult to ensure uniform dispersibility when a charge generating material described later is contained.

  The weight average molecular weight of the rod-shaped polymer is preferably 200,000 to 30 million, more preferably 400,000 to 20 million. In addition, a weight average molecular weight means the weight average molecular weight of conversion of the standard polystyrene by gel permeation chromatography (GPC).

  FIG. 1 is a schematic sectional view showing a preferred embodiment of the electrophotographic photosensitive member of the present invention. As shown in FIG. 1, the electrophotographic photosensitive member 1 includes a conductive support 2 and a photosensitive layer 3. It is configured. The photosensitive layer 3 has a structure in which an undercoat layer 4, a charge generation layer 5, and a charge transport layer 6 are laminated in this order on a conductive support 2. The photosensitive layer 3 of the electrophotographic photoreceptor 1 is a function separation type photoreceptor in which the charge generation layer 5 and the charge transport layer 6 are separated.

  Hereinafter, each component of the electrophotographic photoreceptor 1 will be described in detail. In the present embodiment, the charge generation layer 5 contains the rod-shaped polymer according to the present invention.

  The conductive support 2 is not particularly limited, and for example, a metal such as aluminum, copper, iron, zinc, or nickel can be used. In addition, conductive treatment was performed by depositing metals such as aluminum, copper, gold, silver, platinum, palladium, titanium, nickel-chromium, stainless steel, copper-indium on polymer sheets, paper, plastic, or glass. Things can be used. Further, a conductive sheet obtained by depositing a conductive metal compound such as indium oxide / tin oxide on a polymer sheet, paper, plastic or glass or laminating a metal foil can also be used. In addition, carbon black, indium oxide, tin oxide-antimony oxide powder, metal powder, copper iodide, etc. are dispersed in a binder resin and coated on a polymer sheet, paper, plastic or glass. Those subjected to a conductive treatment can also be used. Examples of the shape of the conductive support 2 include a drum shape, a sheet shape, and a plate shape.

  Here, when a metal pipe substrate is used as the conductive support 2, the surface thereof may be a raw tube, but in advance, mirror cutting, etching, anodizing, rough cutting, centerless grinding, sandblasting, wet It is preferable to perform surface treatment such as honing and coloring treatment. By roughening the surface of the metal pipe base material in this way, it is possible to prevent grain-like density spots due to interference light in the photoconductor that may occur when a coherent light source such as a laser beam is used. it can.

  The undercoat layer 4 includes a material arbitrarily selected from a binder resin, an organic or inorganic powder, an electron transporting substance, and the like. Binder resins include acetal resins such as polyvinyl butyral, polyvinyl alcohol resin, casein, polyamide resin, cellulose resin, gelatin, polyurethane resin, polyester resin, methacrylic resin, acrylic resin, polyvinyl chloride resin, polyvinyl acetate resin, vinyl chloride. -High molecular resin compounds such as vinyl acetate-maleic anhydride resin, silicone resin, silicone-alkyd resin, phenol-formaldehyde resin, melamine resin.

  As materials other than the binder resin, known materials such as a zirconium chelate compound, a titanium chelate compound, an aluminum chelate compound, a titanium alkoxide compound, an organic titanium compound, and a silane coupling agent can be used. These materials can be used alone or as a mixture or polycondensate of two or more. Among these, a zirconium chelate compound and a silane coupling agent are preferable because they have a low residual potential and are excellent in performance in terms of environmental influences and little potential change due to repeated use.

  Examples of the silane coupling agent include vinyltrimethoxysilane, γ-methacryloxypropyl-tris (β-methoxyethoxy) silane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, and γ-glycidoxypropyltri. Methoxysilane, vinyltriacetoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β- (aminoethyl)- Examples include γ-aminopropylmethylmethoxysilane, N, N-bis (β-hydroxyethyl) -γ-aminopropyltriethoxysilane, γ-chloropropyltrimethoxysilane, and the like.

  Among these, particularly preferable compounds include vinyltriethoxysilane, vinyltris (2-methoxyethoxysilane) 3-methacryloxypropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 2- (3,4- Epoxycyclohexyl) ethyltrimethoxysilane, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane, N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-aminopropyltriethoxysilane, Examples include silane coupling agents such as N-phenyl-3-aminopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, and 3-chloropropyltrimethoxysilane.

  Further, as the titanium chelate compound, tetraisopropyl titanate, tetranormal butyl titanate, butyl titanate dimer, tetra (2-ethylhexyl) titanate, titanium acetylacetonate, polytitanium acetylacetonate, titanium octylene glycolate, titanium lactate ammonium salt , Titanium lactate, titanium lactate ethyl ester, titanium triethanolamate, polyhydroxy titanium stearate and the like.

  The film thickness of the undercoat layer 4 is preferably 0.01 to 30 μm, more preferably 0.05 to 25 μm.

  The charge generation layer 5 includes the rod-shaped polymer and the charge generation material described above. The rod-like polymer is used as a binder resin in the charge generation layer 5 and may contain other binder resins. Examples of other resins include polycarbonate resin, polyarylate resin, polyester resin, polyamide resin, polyimide resin, polymetamethyl acrylate resin, polystyrene resin, polysilane resin, polysiloxane resin, and copolymers thereof. These can be used alone or in admixture of two or more. In addition, it is preferable that content of a rod-shaped polymer is 5 mass% or more.

  As the charge generation material, known materials can be used as long as they have a charge generation function, and are not particularly limited, but specific examples are as follows. For example, azo pigments such as bisazo and trisazo, condensed aromatic pigments such as dibromoanthanthrone, perylene pigments, pyrrolopyrrole pigments, phthalocyanine pigments, and selenium. Among these, phthalocyanine pigments such as titanyl phthalocyanine, gallium phthalocyanine, and halogenated tin phthalocyanine are most preferable, and hydroxygallium phthalocyanine is particularly preferable in that the effect of uniform dispersion is particularly large.

  In addition, the blending ratio (mass ratio) of the charge generation material and the binder resin in the charge generation layer 5 is preferably 1:99 to 70:30, more preferably 5:95 to 50:50. If the blending ratio is out of the above range, the charge generation function may not be sufficiently exhibited or the mechanical strength tends to be low.

  The thickness of the charge generation layer 5 is preferably 0.05 to 5 μm, and more preferably 0.1 to 1 μm. If the film thickness of the charge generation layer 5 is less than 0.05 μm, sufficient sensitivity tends not to be obtained, and if the film thickness exceeds 5 μm, a charging failure may occur.

  The charge transport layer 6 includes a charge transport material and a binder resin. The charge transport material may be composed of a polymer compound.

  The charge transport material is not particularly limited as long as it has a function of transporting charges. For example, pyrazoline derivatives, aromatic tertiary amino compounds, aromatic tertiary diamino compounds, 1, 2 , 4-triazine derivatives, hydrazone derivatives quinazoline derivatives, benzofuran derivatives, α-stilbene derivatives, enamine derivatives, carbazole derivatives, poly-N-vinylcarbazole derivatives, hole transport materials, quinone compounds, tetracyanoxydimethane compounds And electron transporting compounds such as fluorenone compounds, oxadiazole compounds, xanthone compounds, thiophene compounds and diphenoquinone compounds, or polymer compounds containing these structures. You may use these individually or in combination of 2 or more types.

  Among these, the compounds represented by the following general formulas (1) to (3) are particularly preferable in terms of high carrier mobility.

[In the above formula, Ar ¹ and Ar ² each independently represents a substituted or unsubstituted aryl group (the substituent of the substituted aryl group includes a halogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group, or A substituted amino group substituted with an alkyl group having 1 to 3 carbon atoms).
R ¹ and R ² each independently represent a halogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkoxy group.
R ³ , R ⁴ , R ⁵ and R ⁶ are each independently an alkyl group having 1 to 5 carbon atoms, an alkoxy group, a substituted amino group substituted with an alkyl group having 1 to 2 carbon atoms, or a substituted or unsubstituted aryl group. Or represents the group represented by the following general formula (4) or the following general formula (5).
R ¹⁰ represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group, a substituted or unsubstituted aryl group, or a group represented by the following general formula (4) or the following general formula (5).
R ^{11 to} R ¹⁴ each independently represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group, a substituted amino group substituted with an alkyl group having 1 to 2 carbon atoms, or a substituted or unsubstituted aryl group. .
a, b, c and d each independently represents an integer of 0 to 2;

Ｒ¹⁵〜Ｒ¹⁷はそれぞれ独立に水素原子、置換若しくは未置換のアルキル基、置換若しくは未置換のアリール基を表す。
Ａｒ^３及びＡｒ^４はそれぞれ独立に置換又は未置換のアリール基を表す。］

R ^{15 to} R ¹⁷ each independently represent a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group.
Ar ³ and Ar ⁴ each independently represent a substituted or unsubstituted aryl group. ]

  Moreover, it does not specifically limit as binder resin used for a charge transport layer, A well-known thing can be used. For example, polycarbonate compounds, polyester compounds, polyarylate compounds, polyimide compounds, polyamide compounds, polystyrene compounds, polysiloxane compounds, charge transporting polyester compounds, charge transporting polycarbonate compounds, and the like can be given. .

  Moreover, it is also possible to add various additives, such as antioxidant and a light stabilizer, as needed. Although it does not specifically limit as antioxidant, For example, a phenol type, hindered amine type, an organic sulfur type antioxidant, etc. are mention | raise | lifted. Further, the light stabilizer is not limited at all, and examples thereof include benzophenone series, benzotriazole series, dithiocarbamate, and tetramethylpiperidine.

  Moreover, the compounding ratio (mass ratio) of the charge transport material and the binder resin in the charge transport layer 6 is preferably 10:90 to 90:10, and more preferably 20:80 to 60:40. If the blending ratio is out of the above range, the mechanical strength and heat resistance may be lowered, or the charge transport function may not be sufficiently exhibited.

  In addition, 5-50 micrometers is preferable and, as for the film thickness of the charge transport layer 6, 15-35 micrometers is more preferable. If the thickness of the charge transport layer 6 is less than 5 μm, the electrical characteristics may not be maintained due to wear of the charge transport layer, and if the thickness exceeds 50 μm, charging failure may occur.

  The electrophotographic photoreceptor of the present invention is not limited to the above configuration. For example, the electrophotographic photoreceptor 1 may be provided with a protective layer on the photosensitive layer 3 or may not have the undercoat layer 4. Further, the stacking order of the charge generation layer 5 and the charge transport layer 6 may be reversed. Furthermore, the photosensitive layer 3 may have a single layer structure. In this case, the undercoat layer 4 and the protective layer are provided even if the undercoat layer 4 is provided between the conductive support 2 and the photosensitive layer 3. You may have both. Furthermore, an intermediate layer may be provided on the undercoat layer.

  The electrophotographic photosensitive member of the present invention having the above-described photosensitive layer is an image forming apparatus such as a laser beam printer, a digital copying machine, an LED printer, or a laser facsimile that emits near-infrared light or visible light, and such image formation. It can be mounted on a process cartridge provided in the apparatus.

(Method for producing electrophotographic photoreceptor)
Next, a method for producing the electrophotographic photoreceptor of the present invention will be described.
First, an object to be processed to be an electrophotographic photosensitive member is prepared by forming a functional layer containing water-soluble rod-like polymers arranged in a predetermined direction. The electrophotographic photoreceptor 1 shown in FIG. 1 has a structure in which an undercoat layer 4, a charge generation layer 5 containing a rod-like polymer, and a charge transport layer 6 are sequentially laminated on a conductive support 2 as described above. Is. Therefore, in this case, the conductive support 2 and the undercoat layer 4 become the objects to be processed.

  In this case, a laminate in which the undercoat layer 4 is formed on the conductive support 2 is prepared as an object to be processed. In order to form the undercoat layer 4 on the conductive support 2, an undercoat layer-forming coating solution is prepared by dissolving / dispersing the above-described binder resin or the like in an organic solvent. It coats on the property support body 2. When dissolving / dispersing the binder resin or the like in the organic solvent, a ball mill, a roll mill, a sand mill, an attritor, an ultrasonic wave, or the like may be used. Examples of the organic solvent include methanol, ethanol, n-propanol, n-butanol, benzyl alcohol, methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, n-butyl acetate, dioxane, tetrahydrofuran, Examples include methylene chloride, chloroform, chlorobenzene, toluene, and the like. These organic solvents can be used alone or in admixture of two or more.

  The coating solution for forming the undercoat layer on the conductive support 2 may be a blade coating method, a Mayer bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method, or a curtain coating. Law. The undercoat layer 4 is formed by removing the solvent from the coating solution applied to the conductive support 2, and the removal of the solvent is usually performed at a temperature at which the film can be formed. In particular, a base material that has been subjected to an acidic solution treatment or a boehmite treatment is preferably formed with an intermediate layer because the defect concealing power of the base material tends to be insufficient. The thickness of the undercoat layer 4 thus formed is 0.01 to 30 μm, preferably 0.05 to 25 μm.

  Even when the electrophotographic photosensitive member 1 has a structure in which a single layer type photosensitive layer containing an undercoat layer 4, a charge generating material, a charge transporting material, and a rod-like polymer is sequentially laminated on a conductive support 2. The laminated body of the support body 2 and the undercoat layer 4 becomes an object to be processed. When the charge transport layer 6 of the electrophotographic photosensitive member 1 contains a rod-like polymer, a laminate of the conductive support 2, the undercoat layer 4, and the charge generation layer 5 is the object to be processed. Further, when the undercoat layer 4 of the electrophotographic photosensitive member 1 contains a rod-like polymer, the conductive support 2 becomes the object to be processed.

  Next, an aqueous solution containing a rod-like polymer is prepared. The content of the rod-like polymer is preferably 5% by mass or more. In addition, the above-described charge generation material can be sufficiently uniformly dispersed in this aqueous solution. When dispersing the rod-like polymer and the charge generating material in water, a ball mill, a roll mill, a sand mill, an attritor, an ultrasonic wave, or the like may be used. In addition, the compounding ratio (mass ratio) of the charge generation material and the rod-shaped polymer is preferably in the range of 1:99 to 70:30.

  Next, an aqueous solution is applied onto the object to be processed and dried to form a functional layer containing a rod-shaped polymer. The object to be processed in this case is a laminate in which the undercoat layer 4 is formed on the conductive support 2 as described above, and the functional layer is the charge generation layer 5. As a method of applying the aqueous solution prepared as described above on this laminate, blade coating method, Mayer bar coating method, spray coating method, dip coating method, bead coating method, air knife coating method, curtain coating method, etc. Is mentioned. The charge generation layer 5 is formed by removing water from the aqueous solution applied to the laminate, but may be heated to a temperature at which film formation is possible in order to remove water. The charge generation layer 5 thus formed has a thickness of 0.05 to 5 μm, preferably 0.1 to 1 μm.

  Then, the charge transport layer 6 is formed on the charge generation layer 5. The charge transport layer 6 can be formed by applying and drying a solution in which a charge transport material and a binder resin are dissolved in an appropriate solvent. The blending ratio between the charge transport material and the binder resin is preferably 10:90 to 90:10.

  In preparing the charge transport layer forming coating solution, a method such as a roll mill, a ball mill, a vibrating ball mill, an attritor, a sand mill, a colloid mill, or a paint shaker can be used as a dispersion method. In addition, as a coating method of the coating liquid, a normal method such as a blade coating method, a wire bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method, or a curtain coating method can be used. . Moreover, the organic solvent used at this time is not specifically limited, A well-known thing can be used. Specific examples include alcohols such as methanol and ethanol, ketones such as acetone, methyl ethyl ketone and cyclohexanone, esters such as ethyl acetate and n-butyl acetate, toluene, tetrahydrofuran and the like. The film thickness of the charge transport layer 6 thus formed is 5 to 50 μm, preferably 15 to 35 μm.

  The electrophotographic photoreceptor of the present invention thus obtained has sufficiently high heat resistance and mechanical strength, and is suitably used in image forming apparatuses such as copying machines and laser printers.

(Image forming device)
FIG. 2 is a sectional view schematically showing a basic configuration of a preferred embodiment of the image forming apparatus of the present invention. An image forming apparatus 200 shown in FIG. 2 includes an electrophotographic photosensitive member 1 according to the present invention, a charging device 208 such as a corotron or a scorotron that charges the electrophotographic photosensitive member 1 by a corona discharge method, and a power source connected to the charging device 208. 209, an exposure device 210 that exposes the electrophotographic photosensitive member 1 charged by the charging device 208 to form an electrostatic latent image, and develops the electrostatic latent image formed by the exposure device 210 to form a toner image. A developing device 211 to be transferred, a transfer device 212 that transfers the toner image developed on the electrophotographic photosensitive member 1 by the developing device 211 to a transfer medium, a cleaning device 213, a static eliminator 214, and a fixing device 215.

  FIG. 3 is a sectional view schematically showing a basic configuration of another embodiment of the image forming apparatus of the present invention. The image forming apparatus 201 shown in FIG. 3 has the same configuration as the image forming apparatus 200 shown in FIG. 2 except that it includes a charging device 208 that charges the electrophotographic photoreceptor 1 of the present invention by a contact method. . In particular, an image forming apparatus that employs a contact-type charging device in which an AC voltage is superimposed on a DC voltage can be preferably used because it has excellent wear resistance. In this case, the static eliminator 214 may not be provided.

  FIG. 4 is a cross-sectional view schematically showing a basic configuration of another embodiment of the image forming apparatus of the present invention. An image forming apparatus 220 shown in FIG. 4 is an intermediate transfer type image forming apparatus. In the housing 400, four electrophotographic photoreceptors 401a to 401d (for example, the electrophotographic photoreceptor 401a is yellow and the electrophotographic photoreceptor 401b is magenta). The electrophotographic photosensitive member 401c can form an image of cyan and the electrophotographic photosensitive member 401d can form a black color) are arranged in parallel along the intermediate transfer belt 409. Here, the electrophotographic photoreceptors 401a to 401d mounted on the image forming apparatus 220 are the electrophotographic photoreceptors of the present invention.

  Each of the electrophotographic photosensitive members 401a to 401d can be rotated in a predetermined direction (counterclockwise on the paper surface), and the charging rolls 402a to 402d, the developing devices 404a to 404d, and the primary transfer roll 410a along the rotation direction. To 410d and cleaning blades 415a to 415d are arranged. Each of the developing devices 404a to 404d can supply toners of four colors of black, yellow, magenta, and cyan accommodated in toner cartridges 405a to 405d. Further, the primary transfer rolls 410a to 410d are in contact with the electrophotographic photosensitive members 401a to 401d via the intermediate transfer belt 409, respectively.

  Further, a laser light source (exposure device) 403 is disposed at a predetermined position in the housing 400, and the surface of the electrophotographic photoreceptors 401a to 401d after charging is irradiated with laser light emitted from the laser light source 403. Is possible. Accordingly, charging, exposure, development, primary transfer, and cleaning are sequentially performed in the rotation process of the electrophotographic photosensitive members 401a to 401d, and the toner images of the respective colors are transferred onto the intermediate transfer belt 409 in an overlapping manner.

  The intermediate transfer belt 409 is supported with a predetermined tension by a drive roll 406, a backup roll 408, and a tension roll 407, and can rotate without causing deflection due to the rotation of these rolls. Further, the secondary transfer roll 413 is disposed so as to contact the backup roll 408 via the intermediate transfer belt 409. The intermediate transfer belt 409 passing between the backup roll 408 and the secondary transfer roll 413 is cleaned by, for example, a cleaning blade 416 disposed in the vicinity of the drive roll 406 and then repeatedly used for the next image forming process. Is done.

  A tray (transfer medium tray) 411 is provided at a predetermined position in the housing 400, and the transfer medium 500 such as paper in the tray 411 is transferred to the intermediate transfer belt 409 and the secondary transfer roll by the transfer roll 412. Then, the paper is sequentially transferred between the two fixing rolls 414 that are in contact with each other and the two fixing rolls 414 that are in contact with each other.

  In the above description, the case where the intermediate transfer belt 409 is used as the intermediate transfer member has been described. However, the intermediate transfer member may have a belt shape like the intermediate transfer belt 409 or a drum shape. Also good. When a belt-shaped configuration such as the intermediate transfer belt 409 is employed as the intermediate transfer member, the thickness of the belt is generally preferably 50 to 500 μm and more preferably 60 to 150 μm, but is appropriately selected according to the hardness of the material. be able to.

  When a drum-shaped configuration is adopted as the intermediate transfer member, it is preferable to use a cylindrical substrate formed of aluminum, stainless steel (SUS), copper, or the like as the substrate. If necessary, an elastic layer can be coated on the cylindrical substrate, and a surface layer can be formed on the elastic layer.

  In the toner used in the present invention, additives such as a colorant, a release agent, an antistatic agent, lubricating particles, and abrasive particles may be used. Examples of colorants include magnetic powders such as magnetite and ferrite, carbon black, aniline blue, chrome yellow, ultramarine blue, deyupon oil red, quinoline yellow, methylene blue chloride, phthalocyanine blue, malachite green oxalate, lamp black, and rose. Bengal, C.I. Pigment Red 48: 1, C.I. Pigment Red 122, C.I. Pigment Red 57: 1, C.I. Pigment Yellow 97, C.I. Pigment Yellow 17, C.I Pigment Blue 15: 1 and CI Pigment Blue 15: 3.

  Specific examples of the release agent include low molecular polyethylene, low molecular polypropylene, Fischer tropish wax, montan wax, carnauba wax, rice wax, and candelilla wax. Examples of the antistatic agent include azo-based metal complex compounds, metal complex compounds of salicylic acid, and resin-type compounds containing a polar group.

  Examples of the lubricant particles include graphite, molybdenum disulfide, talc, low molecular weight polyolefin, aliphatic amides, silicones, and various vegetable waxes. On the other hand, examples of the abrasive include inorganic particles such as cerium oxide, magnesium titanate, and silicon nitride, and organic fine particles such as styrene resin fine particles and styrene acrylic resin fine particles.

  In addition, the color toner for electrophotography is used by mixing with a carrier. As the carrier, iron powder, glass beads, ferrite powder, nickel powder, or those having a resin coating on the surface thereof are used. The mixing ratio with the carrier can be set as appropriate.

(Process cartridge)
FIG. 5 is a cross-sectional view schematically showing a basic configuration of a preferred embodiment of the process cartridge of the present invention. In addition to the electrophotographic photosensitive member 1, the process cartridge 300 includes a charging device 208, a developing device 211, a cleaning device (cleaning means) 213, an opening 218 for exposure, and an opening 217 for static elimination exposure. Are combined and integrated.

  The process cartridge 300 is detachably attached to an image forming apparatus main body including a transfer device 212, a fixing device 215, and other components (not shown), and the image forming apparatus together with the image forming apparatus main body. It constitutes.

  In the above-described image forming apparatus and process cartridge, by using the electrophotographic photosensitive member of the present invention having excellent heat resistance and mechanical strength, it becomes possible to improve image quality and stabilize image quality.

  EXAMPLES Hereinafter, although this invention is demonstrated further more concretely based on an Example and a comparative example, this invention is not limited to a following example at all.

Example 1
The center line average roughness Ra is obtained by subjecting an aluminum pipe having a diameter of 84 mmφ × 347 mm and a thickness of 1 mm to liquid honing using an abrasive (trade name: Alumina Beads CB-A30S, Showa Titanium Co., Ltd., average particle diameter D50 = 30 μm). What roughened so that it might become 0.18 micrometer was used as an electroconductive support body.

  Subsequently, 6 parts by mass of polyvinyl butyral resin (BM-1, manufactured by Sekisui Chemical Co., Ltd.), 12 parts by mass of blocked isocyanate (Sumijoule 3175, manufactured by Sumitomo Bayern Urethane Co., Ltd.) as a curing agent, zinc oxide (Nano Tech ZnO (primary particles) (Diameter 30 nm), manufactured by CI Kasei Co., Ltd.) 41 parts by mass, silicone ball (Tospearl 120, manufactured by Toshiba Silicone) 1 part, silicone oil as leveling agent (SH29PA, manufactured by Toray Dow Corning Silicone) 100 ppm and methyl ethyl ketone 52 parts by mass The material consisting of was dispersed in a batch mill for 10 hours to prepare an undercoat layer forming dispersion. Then, the obtained undercoat layer-forming dispersion was dip-coated on a conductive support, and heated and dried at 150 ° C. for 30 minutes to form an undercoat layer having a thickness of 20.0 μm. A laminate of the conductive support and the undercoat layer thus obtained was prepared as an object to be processed.

  Next, 1 part by mass of DNA (weight average molecular weight 20 million, manufactured by Nichiro) was dissolved in 15 parts by mass of distilled water, and the Bragg angle (2θ ± 0.2 °) in the X-ray diffraction spectrum was 7.5 °. Add 0.3 parts by mass of hydroxygallium phthalocyanine having strong diffraction peaks at 9.9 °, 12.5 °, 16.3 °, 18.6 °, 25.1 °, 28.3 °, and 30 ° C. with a sand mill. Dispersed for 2 hours. The obtained dispersion was filtered, and the filtrate was dip coated on the object to be treated and dried at 150 ° C. for 50 hours to form a charge generation layer having a thickness of 0.15 μm.

  Next, 3 parts by mass of bisphenol Z-type polycarbonate (Iupilon Z300 (weight average molecular weight 50,000), manufactured by Mitsubishi Chemical) and 2 parts by mass of a benzidine compound (Compound 1 in Table 1) were dissolved in 20 parts by mass of tetrahydrofuran. The solution was dip coated on the charge generation layer and dried at 140 ° C. for 1 hour to form a charge transport layer to obtain an electrophotographic photosensitive drum.

  Further, an electrophotographic photoreceptor sheet was obtained by the same method as described above except that the aluminum pipe was replaced with an aluminum sheet having a thickness of 50 μm.

(Example 2)
Electrophotographic photosensitization by the same method as in Example 1 except that 1 part by weight of DNA (weight average molecular weight 2 million, manufactured by Nichiro) was used instead of 1 part by weight of DNA (weight average molecular weight 20 million, manufactured by Nichiro). A body drum and an electrophotographic photosensitive sheet were obtained.

(Example 3)
In the charge generation layer of Example 1, the Bragg angle (2θ ± 0.2 °) in the X-ray diffraction spectrum is 7.5 °, 9.9 °, 12.5 °, 16.3 °, 18.6 °, An electrophotographic photosensitive drum and an electrophotographic photosensitive sheet are obtained in the same manner as in Example 1 except that 0.1 part by mass of hydroxygallium phthalocyanine having strong diffraction peaks at 25.1 ° and 28.3 ° is used. It was.

(Example 4)
In the charge generation layer of Example 1, the Bragg angle (2θ ± 0.2 °) in the X-ray diffraction spectrum is 7.5 °, 9.9 °, 12.5 °, 16.3 °, 18.6 °, An electrophotographic photosensitive drum and an electron are produced in the same manner as in Example 1 except that hydroxygallium phthalocyanine having strong diffraction peaks at 25.1 ° and 28.3 ° and a spectral absorption spectrum having an absorption maximum at 826 nm is used. A photographic photoreceptor sheet was obtained.

(Example 5)
In the charge generation layer of Example 1, the Bragg angles (2θ ± 0.2 °) in the X-ray diffraction spectrum have strong diffraction peaks at 7.4 °, 16.6 °, 25.5 °, and 28.3 °. An electrophotographic photosensitive drum and an electrophotographic photosensitive sheet were obtained in the same manner as in Example 1 except that chlorogallium phthalocyanine was used.

(Example 6)
In the charge generation layer of Example 1, the same method as in Example 1 was used except that titanyl phthalocyanine having a main peak at a Bragg angle (2θ ± 0.2 °) of 28.6 ° in the X-ray diffraction spectrum was used. An electrophotographic photosensitive drum and an electrophotographic photosensitive sheet were obtained.

(Example 7)
In the charge generation layer of Example 1, the Bragg angles (2θ ± 0.2 °) in the X-ray diffraction spectrum have strong diffraction peaks at 9.0 °, 14.2 °, 23.9 °, and 27.1 °. An electrophotographic photosensitive drum and an electrophotographic photosensitive sheet were obtained in the same manner as in Example 1 except that oxytitanium phthalocyanine was used.

(Example 8)
In the undercoat layer of Example 1, 10 parts by mass of tin dioxide-coated barium sulfate, 2 parts by mass of titanium oxide, 6 parts by mass of phenol resin, 0.001 part by mass of silicone oil, 4 parts by mass of methanol, and 16 parts by mass of methoxypropanol A dispersion liquid dispersed in a mixed solvent is dip-coated on a conductive support and dried at 140 ° C. for 30 minutes to obtain a conductive layer having a thickness of 15 μm. A subbing layer provided with an intermediate layer having a thickness of 0.5 μm by dip-coating a coating solution prepared by dissolving 3 parts by mass of polymerized nylon in a mixed solvent of 65 parts by mass of methanol and 30 parts by mass of n-butanol and drying. An electrophotographic photosensitive drum and an electrophotographic photosensitive sheet were obtained in the same manner as in Example 1 except that they were used.

Example 9
In the charge generation layer of Example 1, the electrophotographic photosensitive drum and the electrophotographic photosensitive drum were prepared in the same manner as in Example 1 except that the compound represented by Compound 2 was used instead of the benzidine compound represented by Compound 1 in Table 1. An electrophotographic photosensitive sheet was obtained.

(Example 10)
2 parts by weight of the compound 3 shown in Table 1, 2 parts by weight of methyltrimethoxysilane, 0.5 parts by weight of tetramethoxysilane, 0.3 parts by weight of colloidal silica, 5 parts by weight of isopropyl alcohol, 3 parts by weight of tetrahydrofuran, and 0 distilled water After dissolving in 3 parts by mass, 0.5 part by mass of ion exchange resin (Amberlyst 15E) was added, and the mixture was stirred at room temperature to conduct a hydrolysis reaction for 24 hours. The ion exchange resin was separated by filtration from this reaction solution, and 0.1 parts by mass of aluminum trisacetylacetonate (Al (aqaq) ₃ ), 3,5-di-t-butyl-4-hydroxytoluene was obtained. (BHT) 0.4 parts by mass, polytetrafluoroethylene particles (trade name: Lubron L-2 manufactured by Daikin Industries, Ltd.) 0.02 parts by mass were added, and the surface of the electrophotographic photosensitive member obtained in Example 1 was added to this coating solution. After being applied by a ring-type dip coating method and dried at room temperature for 30 minutes, it was cured by heating at 170 ° C. for 1 hour to obtain an electrophotographic photosensitive drum having a protective layer having a thickness of about 3 μm. Moreover, after preparing a coating liquid by the method similar to the above, the electrophotographic photoreceptor sheet was obtained by simple dip coating on the surface of the electrophotographic photoreceptor of Example 1.

(Example 11)
2 parts by mass of each of the compounds 4 and 5 in Table 1 and 0.05 parts by mass of tetramethoxysilane were dissolved in 5 parts by mass of isopropyl alcohol, 3 parts by mass of tetrahydrofuran, and 0.3 parts by mass of distilled water, and ions were added thereto. Hydrolysis reaction was performed for 24 hours by adding 0.05 part by mass of an exchange resin (Amberlyst 15E) and stirring at room temperature. The ion exchange resin was separated by filtration from this reaction solution, and 0.04 part by mass of aluminum trisacetylacetonate and 0.02 part by mass of 3,5-di-tert-butyl-4-hydroxytoluene were added to 2 parts by mass of the obtained filtrate. The coating solution was applied to the surface of the electrophotographic photoreceptor obtained in Example 1 by the ring-type dip coating method, dried at room temperature for 30 minutes, and then cured by heat treatment at 170 ° C. for 1 hour. An electrophotographic photosensitive drum having a protective layer with a thickness of about 3 μm was obtained. Moreover, after preparing the coating liquid by the method similar to the above, the electrophotographic photoreceptor sheet was obtained by simple dip coating on the surface of the electrophotographic photoreceptor of Example 1.

Example 12
In the charge generation layer of Example 1, an electrophotographic photosensitive drum and an electrophotographic photosensitive sheet were obtained in the same manner as in Example 1 except that 1 part by mass of t-selenium was used instead of hydroxygallium phthalocyanine.

(Comparative Example 1)
In the charge generation layer of Example 1, a solution prepared by dissolving 1 part by mass of polyvinyl butyral resin (trade name: Eslac BM-1 manufactured by Sekisui Chemical Co., Ltd.) in 50 parts by mass of n-butyl acetate, and a Bragg angle in an X-ray diffraction spectrum Hydroxy with strong diffraction peaks at (2θ ± 0.2 °) at 7.5 °, 9.9 °, 12.5 °, 16.3 °, 18.6 °, 25.1 °, 28.3 ° A dispersion obtained by mixing 1 part by mass of gallium phthalocyanine and dispersing for 5 hours with a sand mill is dip coated on the undercoat layer and dried at 100 ° C. for 10 minutes to form a charge generation layer having a thickness of 0.2 μm. Obtained. Otherwise, an electrophotographic photosensitive drum and an electrophotographic photosensitive sheet were obtained in the same manner as in Example 1.

(Comparative Example 2)
In the charge generation layer of Example 1, a solution prepared by dissolving 1 part by mass of polyvinyl butyral resin (trade name: Eslac BM-1 manufactured by Sekisui Chemical Co., Ltd.) in 50 parts by mass of n-butyl acetate, and a Bragg angle in an X-ray diffraction spectrum Hydroxy with strong diffraction peaks at (2θ ± 0.2 °) at 7.5 °, 9.9 °, 12.5 °, 16.3 °, 18.6 °, 25.1 °, 28.3 ° A dispersion obtained by mixing 0.3 part by mass of gallium phthalocyanine and dispersing in a sand mill for 5 hours is dip coated on the undercoat layer, dried at 100 ° C. for 10 minutes, and a charge generation layer having a thickness of 0.2 μm Got. Otherwise, an electrophotographic photosensitive drum and an electrophotographic photosensitive sheet were obtained in the same manner as in Example 1.

(Comparative Example 3)
In the charge generation layer of Example 1, an electrophotographic photosensitive drum and an electrophotographic photosensitive sheet were obtained by the same method as in Example 1 except that the charge generation layer was formed by the following method. That is, 1 part by mass of DNA (weight average molecular weight 2 million, manufactured by Nichiro) was dissolved in 100 parts by mass of distilled water, and N, N, N-trimethyl-N- (3,6,9,12-tetraoxa When 0.5 parts by mass of docosyl ammonium bromide (TTA) was added and stirred, a white precipitate was deposited, and then the white precipitate was filtered, and 1 part by mass of the white precipitate as a solid was dissolved in 20 parts by mass of tetrahydrofuran. 2,6-diphenyl-4- (4-N, N-dimethylaminophenyl) thiopyrylium perchlorate (1 part by mass) was added and mixed, and the solution was filtered. And a charge generation layer having a thickness of 0.3 μm was formed by drying at 60 ° C. for 1 hour.

(Evaluation of electrophotographic characteristics)
In order to evaluate the electrophotographic characteristics of the electrophotographic photoreceptor sheets of Examples 1 to 12 and Comparative Examples 1 to 3 obtained as described above, the electrophotographic characteristics were measured by the following procedure. In an environment of 20 ° C. and 50% RH, an electrophotographic photoreceptor sheet is subjected to corona discharge of −5.0 kV using an electrostatic copying paper test apparatus (EPA8200, manufactured by Kawaguchi Electric Co., Ltd.) using a 20 mmφ small area mask. Was negatively charged. Next, a halogen lamp light split at 780 nm using an interference filter was adjusted and irradiated on the surface of the photoreceptor so as to be 5.0 μW / cm ² . The initial surface potential V ₀ [V] at that time, the half exposure amount E _1/2 [μJ / cm ² ] until the surface potential becomes 1/2 of V ₀ , and the residual potential V _R after 10 seconds from the start of exposure. [V] was measured. The measurement results are shown in Table 2.

  Further, the electrophotographic photosensitive drums of Examples 1 to 12 and Comparative Examples 1 to 3 are mounted on an image forming apparatus (full color printer Docu Print C620, manufactured by Fuji Xerox Co.) having the configuration shown in FIG. The image quality after sheet printing was evaluated visually as the image quality stability over time. The image forming apparatus was installed in an environment of a temperature of 40 ° C. and a humidity of 90% and an environment of a temperature of 10 ° C. and a humidity of 40%, and the image quality after printing 100 sheets was visually evaluated as the image quality environment dependency. . Furthermore, only the charge generation layer was formed by cast film formation, and the glass transition temperature was measured with a differential scanning calorimeter (DSC-60A, manufactured by Shimadzu Corporation). The obtained results are shown in Table 2.

In the image forming apparatus described above, a roller charger (BCR) as a charging device, ROS using a 780 nm semiconductor laser as an exposure device, a two-component reversal development method as a development method, and a roller charger (BTR) as a transfer device. ) And belt intermediate transfer system as the transfer device.

  As is apparent from the results in Table 2, in the electrophotographic photoreceptors of Examples 1 to 12, since the charge generation layer as the functional layer contains a rod-like polymer, it exhibits high heat resistance and the charge generation material is uniform. Therefore, it is excellent in mechanical strength. Therefore, the process cartridge and the image forming apparatus provided with such an electrophotographic photosensitive member have high chargeability and sensitivity, can suppress the residual potential, and realize extremely high image quality. Furthermore, the electrophotographic photoreceptors of Examples 1 to 12 were excellent in high image quality stability over time and environmental stability.

  On the other hand, since the electrophotographic photoreceptors of Comparative Examples 1 to 3 have low heat resistance of the charge generation layer and the dispersion of the charge generation material is not uniform, the process cartridge and the image forming apparatus provided with such an electrophotographic photoreceptor have sensitivity. It was low, the residual potential was high, and the image quality was not high. Further, due to environmental changes over time, deterioration of the image quality such as fogging, density defects, streak defects, etc. occurred due to deterioration of the surface of the charge generation layer.

1 is a schematic cross-sectional view showing a preferred embodiment of an electrophotographic photoreceptor of the present invention. 1 is a schematic diagram illustrating a basic configuration of a preferred embodiment of an image forming apparatus of the present invention. It is a schematic diagram which shows the basic composition of other suitable embodiment of the image forming apparatus of this invention. It is a schematic diagram which shows the basic composition of other suitable one Embodiment of the image forming apparatus of this invention. It is a schematic diagram showing a basic configuration of a preferred embodiment of the process cartridge of the present invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Electrophotographic photoreceptor, 2 ... Electroconductive support body, 3 ... Photosensitive layer, 4 ... Undercoat layer, 5 ... Charge generation layer, 6 ... Charge transport layer.

Claims (6)

An electrophotographic photoreceptor comprising a charge generation layer containing DNA which is a water-soluble rod-like polymer. 2. The electrophotographic photoreceptor according to claim 1, wherein the content of the DNA is 5% by mass or more. The electrophotographic photosensitive member according to claim 1 or 2, wherein the charge generating layer further contains a phthalocyanine pigment. A step of preparing an object to be processed to be an electrophotographic photosensitive member by forming a charge generation layer containing DNA which is a water-soluble rod-like polymer;
Preparing an aqueous solution containing the DNA;
Applying the aqueous solution onto the object to be treated and drying to form a charge generation layer containing the DNA;
A method for producing an electrophotographic photoreceptor, comprising: The electrophotographic photosensitive member according to any one of claims 1 to 3 ,
A charging device for charging the photoreceptor;
An exposure device that exposes the charged photoreceptor to form an electrostatic latent image on the photoreceptor;
A developing device for developing the electrostatic latent image to form a toner image on the photoreceptor;
A transfer device for transferring the toner image on the photoreceptor to a transfer medium;
An image forming apparatus comprising: The electrophotographic photosensitive member according to any one of claims 1 to 3 ,
Selected from a charging device for charging the photoconductor, a developing device for developing the electrostatic latent image to form a toner image on the photoconductor, and a cleaning device for removing toner remaining on the photoconductor after the transfer process. At least one,
A process cartridge comprising:

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