JP2009031721A - Electrophotographic photoreceptor, process cartridge, image forming apparatus, and film forming coating solution - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor high in mechanical strength of the outermost layer of a photosensitive layer, capable of preventing separation, of preventing degradation of electric characteristics and image quality characteristics by repeated use over a long time, and of stably providing an image having low environment dependency. <P>SOLUTION: This electrophotographic photoreceptor has a conductive substrate and a photosensitive layer provided on a surface of the conductive substrate, and is characterized in that the outermost layer of the photosensitive layer is formed by containing a crosslinked product using a guanamine compound and at least one kind of charge transporting material having at least one substitution group selected from a group consisting of -OH, -OCH<SB>3</SB>, -NH, -SH, and -COOH. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an electrophotographic photosensitive member, a process cartridge, an image forming apparatus, and a coating forming coating solution.

  An electrophotographic image forming apparatus generally has the following configuration and process. That is, the surface of the electrophotographic photosensitive member is charged to a predetermined polarity and potential by a charging unit, and the surface of the electrophotographic photosensitive member after charging is selectively discharged by image exposure to form an electrostatic latent image. The latent image is developed as a toner image by attaching toner to the electrostatic latent image by the developing unit, and the toner image is transferred to a transfer medium by the transfer unit, and discharged as an image formed product.

  In recent years, electrophotographic photoreceptors have the advantage of being able to obtain high speed and high printing quality, and thus have been remarkably used in the fields of copying machines and laser beam printers. As an electrophotographic photosensitive member used in these image forming apparatuses, it is inexpensive, manufacturable and disposable compared to conventional electrophotographic photosensitive members using inorganic photoconductive materials such as selenium, selenium-tellurium alloy, selenium-arsenic alloy, cadmium sulfide. Organic photoreceptors using organic photoconductive materials that have advantages in terms of the point have come to dominate.

  Conventionally, a corona charging method using a corona discharger has been used as the charging method. However, in recent years, a contact charging method having advantages such as low ozone and low power has been put into practical use and has been actively used. In the contact charging method, a conductive member as a charging member is brought into contact with or close to the surface of the photosensitive member, and a voltage is applied to the charging member to charge the surface of the photosensitive member. In addition, as a method of applying to the charging member, there are a direct current method in which only a direct current voltage is applied and an alternating current superposition method in which an alternating current voltage is superimposed on the direct current voltage. This contact charging method has the advantage that the apparatus can be downsized and the generation of gas such as ozone is small.

  As a transfer method, a method of directly transferring to paper has been the mainstream. However, in recent years, a method of transferring using an intermediate transfer member has been widely used because the degree of freedom of the transferred paper is widened.

  On the other hand, it is possible to suppress photoreceptor deterioration and wear by the contact charging method, and to prevent the photoreceptor from being scratched or pierced by the direct charging method or the use of an intermediate transfer member. In order to suppress the occurrence of a phenomenon in which a current flows), it has been proposed to improve the strength by providing a protective layer on the surface of the electrophotographic photoreceptor. As a material system for forming the protective layer, for example, Patent Document 1 proposes a material in which conductive powder is dispersed in a phenol resin. Patent Document 2 proposes an organic-inorganic hybrid material. Patent Document 3 proposes a chain polymerizable material. Patent Document 4 proposes an acrylic material. Patent Document 5 proposes an alcohol-soluble charge transport material and a phenol resin.

  Patent Document 6 proposes a cured film of an alkyl etherified benzoguanamine / formaldehyde resin and an electron-accepting carboxylic acid or an electron-accepting polycarboxylic acid anhydride. Patent Document 7 discloses a cured film obtained by doping a benzoguanamine resin with iodine, an organic sulfonic acid compound, or ferric chloride. Patent Document 8 discloses a specific additive and a phenol resin, a melamine resin, a benzoguanamine resin, and a siloxane resin. Alternatively, a cured film with a urethane resin has been proposed.

Japanese Patent No. 3287678 Japanese Patent Laid-Open No. 12-019749 JP 2005-234546 A JP 2000-66424 A JP 2002-82469 A Japanese Patent Laid-Open No. 62-251757 Japanese Patent Laid-Open No. 7-146564 JP 2006-84711 A

  For example, the electrophotographic photosensitive members disclosed in Patent Documents 2 to 4 and Patent Documents 6 to 8 have high mechanical strength and high abrasion resistance, so that the life can be extended. On the other hand, the protective layer using the phenol resin disclosed in Patent Document 5 has a high gas barrier property and a high resistance to an oxidizing gas such as a discharge product, and a stable image for a long time. It is excellent in points.

The problems of the present invention are that the outermost layer of the photosensitive layer has a high mechanical strength and is prevented from peeling off, and the deterioration of the electrical characteristics and image quality characteristics due to repeated use over a long period of time is suppressed. An electrophotographic photosensitive member is provided.
Another object of the present invention is to provide a process cartridge and an image forming apparatus using the electrophotographic photosensitive member.
Moreover, the subject of this invention is providing the coating liquid for film formation in which the film | membrane excellent in the adhesiveness with respect to a lower layer is formed, and the performance degradation by repeated use over a long term is suppressed.

  The above problem is solved by the following means. That is,

The invention according to claim 1
A conductive substrate;
A photosensitive layer provided on the surface of the conductive substrate;
Have
The outermost surface layer of the photosensitive layer is a guanamine compound and at least one kind of charge transporting material having at least one substituent selected from —OH, —OCH ₃ , —NH ₂ , —SH, and —COOH. An electrophotographic photoreceptor characterized in that it comprises a cross-linked product using

The invention according to claim 2
2. The electrophotographic photoreceptor according to claim 1, wherein the guanamine compound is at least one of a compound represented by the following general formula (A) and a multimer thereof.

(In the general formula (A), R ₁ is a linear or branched alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted phenyl group having 6 to 10 carbon atoms, or 4 carbon atoms. The substituted or unsubstituted alicyclic hydrocarbon group is 10 or more and R _{2 to} R ₅ each independently represents hydrogen, —CH ₂ —OH, or —CH ₂ —O—R ₆ , R _6. Represents hydrogen or a linear or branched alkyl group having 1 to 10 carbon atoms.)

The invention according to claim 3
In the general formula (A), R ₁ represents a substituted or unsubstituted phenyl group having 6 to 10 carbon atoms, and R _{2 to} R ₅ represent —CH ₂ —O—R _6. 2. The electrophotographic photosensitive member according to 2.

The invention according to claim 4
4. The electrophotographic photosensitive member according to claim 2, wherein in the general formula (A), R ₆ is selected from a methyl group and an n-butyl group.

The invention according to claim 5
The charge transporting material is a charge transporting material having at least three substituents selected from —OH, —OCH ₃ , —NH ₂ , —SH, and —COOH. 5. The electrophotographic photosensitive member according to any one of 4 above.

The invention according to claim 6
The electrophotographic photosensitive member according to any one of claims 1 to 3, wherein the charge transporting material is a compound represented by the following general formula (I).
_{F - ((- R 7 -X} ) n1 R 8 -Y) n2 (I)
(In general formula (I), F is an organic group derived from a compound having a hole transporting ability, and R ₇ and R ₈ are each independently a linear or branched alkylene group having 1 to 5 carbon atoms. , N1 represents 0 or 1, n2 represents an integer of 1 to 4, X represents an oxygen, NH, or sulfur atom, Y represents —OH, —OCH ₃ , —NH ₂ , —SH, or — COOH is shown.)

The invention according to claim 7 provides:
7. The electrophotographic photoreceptor according to claim 6, wherein in the compound represented by the general formula (I), n2 represents 3 or 4.

The invention according to claim 8 provides:
An electrophotographic photoreceptor according to any one of claims 1 to 7,
Charging means for charging the electrophotographic photosensitive member, developing means for developing the electrostatic latent image formed on the electrophotographic photosensitive member with toner, and toner removal for removing toner remaining on the surface of the electrophotographic photosensitive member At least one selected from the group consisting of means.

The invention according to claim 9 is:
9. The process cartridge according to claim 8, wherein the developing unit includes a developer holder that moves in a direction opposite to a moving direction of the electrophotographic photosensitive member.

The invention according to claim 10 is:
An electrophotographic photoreceptor according to any one of claims 1 to 7,
Charging means for charging the electrophotographic photoreceptor;
Electrostatic latent image means for forming an electrostatic latent image on the charged electrophotographic photosensitive member;
Developing means for developing the electrostatic latent image formed on the electrophotographic photosensitive member with toner;
Transfer means for transferring the toner image to a transfer object;
An image forming apparatus comprising:

The invention according to claim 11
The image forming apparatus according to claim 10, wherein the developing unit includes a developer holder that moves in a direction opposite to a moving direction of the electrophotographic photosensitive member.

The invention according to claim 12
Coating solution for forming a film, comprising at least a guanamine compound and at least one charge transporting material having at least one substituent selected from —OH, —OCH ₃ , —NH ₂ , —SH, and —COOH. It is.

The invention according to claim 13 is:
A conductive substrate;
A photosensitive layer provided on the surface of the conductive substrate;
Have
The outermost surface layer of the photosensitive layer is a guanamine compound and at least one kind of charge transporting material having at least one substituent selected from —OH, —OCH ₃ , —NH ₂ , —SH, and —COOH. An electrophotographic photoreceptor characterized in that it comprises a cross-linked product obtained by applying a film-forming coating solution containing

  According to the first aspect of the present invention, the mechanical strength of the outermost layer of the photosensitive layer is high and peeling is suppressed, deterioration of electrical characteristics and image quality characteristics due to repeated use over a long period of time is suppressed, and environmental dependency is low and stable. To obtain an image.

  According to the invention of claim 2, the mechanical strength of the outermost layer of the photosensitive layer is more effectively suppressed and the peeling is suppressed, and the deterioration of the electrical characteristics and the image quality characteristics due to repeated use over a long period is suppressed. The image is obtained with low stability.

  According to the invention of claim 3, the mechanical strength of the outermost layer of the photosensitive layer is more effectively suppressed and peeling is suppressed, and deterioration of electrical characteristics and image quality characteristics due to repeated use over a long period of time is suppressed. The image is obtained with low stability.

  According to the invention according to claim 4, the mechanical strength of the outermost layer of the photosensitive layer is more effectively suppressed and peeling is suppressed, and deterioration of electrical characteristics and image quality characteristics due to repeated use over a long period of time is suppressed. The image is obtained with low stability.

  According to the invention of claim 5, the crosslinking density is increased and a stronger crosslinked film is obtained. In particular, the rotational torque of the electrophotographic photosensitive member when using a blade cleaner is reduced, and the damage to the blade is suppressed. In addition, wear of the electrophotographic photosensitive member is suppressed.

  According to the invention of claim 6, the mechanical strength of the outermost layer of the photosensitive layer is high and peeling is suppressed, deterioration of electrical characteristics and image quality characteristics due to repeated use over a long period of time is suppressed, and environmental dependency is low and stable. To obtain an image.

  According to the invention of claim 7, the crosslinking density is increased and a stronger crosslinked film can be obtained. In particular, the rotational torque of the electrophotographic photosensitive member when using a blade cleaner is reduced, and the damage to the blade is suppressed. In addition, wear of the electrophotographic photosensitive member is suppressed.

  According to the eighth aspect of the invention, environmental dependence is reduced over a long period of time, and an image can be stably obtained.

  According to the ninth aspect of the present invention, the surface of the electrophotographic photosensitive member is rubbed with the toner remaining between the developer holding member and the electrophotographic photosensitive member, and the discharge product attached to the surface of the electrophotographic photosensitive member ( In particular, the scraping property of the low-resistance substance due to ozone and NOx is improved, and the accumulation of discharge products is suppressed for a very long time.

  According to the invention of claim 10, environmental dependence is reduced over a long period of time, and an image can be obtained stably.

  According to the eleventh aspect of the present invention, the surface of the electrophotographic photosensitive member is rubbed with the toner remaining between the developer holding member and the electrophotographic photosensitive member, and the discharge product attached to the surface of the electrophotographic photosensitive member ( In particular, the scraping property of the low-resistance substance due to ozone and NOx is improved, and the accumulation of discharge products is suppressed for a very long time.

  According to the invention which concerns on Claim 12, the film | membrane excellent in the adhesiveness with respect to a lower layer is formed, and the performance degradation by repeated use over a long term is suppressed.

  According to the invention of claim 13, the mechanical strength of the outermost layer of the photosensitive layer is high and the peeling is suppressed, the deterioration of the electrical characteristics and the image quality characteristics due to repeated use over a long period of time is suppressed, and the environmental dependency is low and stable. To obtain an image.

(Electrophotographic photoreceptor)
The electrophotographic photoreceptor according to the exemplary embodiment includes a conductive substrate and a photosensitive layer provided on the surface of the conductive substrate, and the outermost surface layer of the photosensitive layer includes a guanamine compound and a specific electrotransport material described later. It is the layer comprised including the crosslinked material using these.

  In the electrophotographic photoreceptor according to the exemplary embodiment, the above-described configuration has high mechanical strength of the outermost layer of the photosensitive layer and suppresses peeling, and deterioration of electrical characteristics and image quality characteristics due to repeated use over a long period is suppressed. The image can be obtained stably with low environmental dependency. The reason for this is not clear, but is presumed as follows.

  The guanamine compound having a guanamine skeleton and the charge transporting material having a specific functional group form a film that is highly cross-linked and in which fluctuations in electrical properties are suppressed by the environment. In addition, by using the specific compound, volume shrinkage hardly occurs at the time of crosslinking (curing), and adhesion with the lower layer of the formed film is also improved.

In particular, when a compound represented by the general formula (A) is used as the guanamine compound, since the compound has a functional group (corresponding to R _{1 in the} formula) imparting appropriate hydrophobicity, the adsorption of the gas generated by the discharge and moisture Adsorption is suppressed, and a maximum of four cross-linking sites (cross-linking sites) exist in one molecule, so that a highly cross-linked film is obtained. In addition, when the compound represented by the general formula (I) is used as the specific charge transporting material, it is highly crosslinked, and the electrophotographic characteristics, electric resistance characteristics and the like are enhanced.

  In addition, since a specific compound is used, the film has a high hardness, and the occurrence of leakage is prevented by reducing the piercing of the conductive foreign matter mixed from the inside and outside of the image forming apparatus into the photoconductor. Furthermore, film wear can be suppressed, and leakage can be prevented even when used repeatedly for a long time.

  Therefore, the electrophotographic photosensitive member according to this embodiment is presumed to have the above effect.

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

(Electrophotographic photoreceptor)
The electrophotographic photoreceptor used in the present invention will be described below.
FIG. 1 is a schematic cross-sectional view showing a preferred embodiment of the electrophotographic photoreceptor according to the embodiment. 2 to 3 are schematic sectional views showing electrophotographic photosensitive members according to other embodiments.

  The electrophotographic photoreceptor 7 shown in FIG. 1 is provided with a subbing layer 1 on a conductive substrate 4, and a photosensitive layer in which a charge generation layer 2, a charge transport layer 3, and a protective layer 5 are sequentially formed thereon. It has been.

  The electrophotographic photosensitive member 7 shown in FIG. 2 includes a photosensitive layer in which the functions are separated into the charge generation layer 2 and the charge transport layer 3 as in the electrophotographic photosensitive member 7 shown in FIG. The electrophotographic photoreceptor 7 shown in FIG. 3 contains the charge generation material and the charge transport material in the same layer (single-layer type photosensitive layer 6 (charge generation / charge transport layer)).

  In the electrophotographic photosensitive member 7 shown in FIG. 2, an undercoat layer 1 is provided on a conductive substrate 4, and a photosensitive layer in which a charge transport layer 3, a charge generation layer 2, and a protective layer 5 are sequentially formed thereon. Is provided. In the electrophotographic photoreceptor 7 shown in FIG. 3, the undercoat layer 1 is provided on the conductive substrate 4, and the photosensitive layer in which the single-layer type photosensitive layer 6 and the protective layer 5 are sequentially formed thereon is provided. It has been.

  The electrophotographic photoreceptor 7 shown in FIGS. 1 to 3 corresponds to the outermost surface layer. In the electrophotographic photoreceptor shown in FIGS. 1 to 3, the undercoat layer may or may not be provided.

  Hereinafter, each element will be described based on the electrophotographic photoreceptor 7 shown in FIG. 1 as a representative example.

<Conductive substrate>
Examples of the conductive substrate 4 include a metal plate, a metal drum, and a metal belt formed using a metal or an alloy such as aluminum, copper, zinc, stainless steel, chromium, nickel, molybdenum, vanadium, indium, gold, or platinum. Alternatively, a paper, a plastic film, a belt, or the like on which a conductive compound such as a conductive polymer or indium oxide, or a metal or alloy such as aluminum, palladium, or gold is applied, vapor-deposited, or laminated can be given. Here, “conductive” means that the volume resistivity is less than 10 ¹³ Ωcm.

  When the electrophotographic photoreceptor 7 is used in a laser printer, the surface of the conductive substrate 4 has a center line average roughness Ra of 0.04 μm or more and 0 in order to prevent interference fringes generated when laser light is irradiated. It is desirable to roughen the surface to 5 μm or less. If Ra is less than 0.04 μm, it becomes close to a mirror surface, so that the effect of preventing interference tends to be insufficient. If Ra exceeds 0.5 μm, the image quality tends to be rough even if a film is formed. When non-interfering light is used for the light source, it is not particularly necessary to roughen the interference fringes, and it is possible to prevent the occurrence of defects due to the irregularities on the surface of the conductive substrate 4, and thus it is suitable for longer life.

  Surface roughening methods include wet honing by suspending the abrasive in water and spraying it on the support, or centerless grinding and anodic oxidation in which the support is pressed against a rotating grindstone and continuously ground. Processing is desirable.

  As another roughening method, a conductive or semiconductive powder is dispersed in a resin without roughening the surface of the conductive substrate 4 to form a layer on the surface of the support. A method of roughening with particles dispersed in the layer is also desirably used.

  Here, the roughening treatment by anodic oxidation is to form an oxide film on the aluminum surface by anodizing in an electrolyte solution using aluminum as an anode. Examples of the electrolyte solution include a sulfuric acid solution and an oxalic acid solution. However, the porous anodic oxide film formed by anodic oxidation is chemically active as it is, easily contaminated, and has a large resistance fluctuation due to the environment. Therefore, the pores of the anodic oxide film are sealed with pressurized water vapor or boiling water (a metal salt such as nickel may be added) by volume expansion due to a hydration reaction, and a sealing process is performed to change to a more stable hydrated oxide. It is desirable.

  The thickness of the anodic oxide film is desirably 0.3 μm or more and 15 μm or less. When this film thickness is less than 0.3 μm, the barrier property against implantation tends to be poor and the effect tends to be insufficient. On the other hand, if it exceeds 15 μm, the residual potential tends to increase due to repeated use.

  Further, the conductive substrate 4 may be subjected to treatment with an acidic aqueous solution or boehmite treatment. The treatment with an acidic treatment liquid containing phosphoric acid, chromic acid and hydrofluoric acid is carried out as follows. First, an acidic treatment liquid is prepared. The mixing ratio of phosphoric acid, chromic acid and hydrofluoric acid in the acidic treatment liquid is such that phosphoric acid is in the range of 10% by mass to 11% by mass, chromic acid is in the range of 3% by mass to 5% by mass, and hydrofluoric acid is 0.00%. The concentration of these acids is preferably in the range of 13.5 mass% to 18 mass%. The treatment temperature is preferably 42 ° C. or more and 48 ° C. or less, but by keeping the treatment temperature high, a thicker film can be formed faster than when the treatment temperature is lower than the range. The film thickness is preferably from 0.3 μm to 15 μm. If it is less than 0.3 μm, the barrier property against injection tends to be poor and the effect tends to be insufficient. On the other hand, when it exceeds 15 μm, there is a tendency that the residual potential increases due to repeated use.

  The boehmite treatment is performed by immersing in pure water at 90 ° C. or more and 100 ° C. or less for 5 minutes or more and 60 minutes or less, or by contacting with heated steam at 90 ° C. or more and 120 ° C. or less for 5 minutes or more and 60 minutes or less. The film thickness is preferably 0.1 μm or more and 5 μm or less. This is further anodized using an electrolyte solution with lower film solubility than other types such as adipic acid, boric acid, borate, phosphate, phthalate, maleate, benzoate, tartrate, citrate, etc. It may be processed.

<Underlayer>
The undercoat layer 1 is configured by containing inorganic particles in a binder resin, for example.
As the inorganic particles, powder resistance (volume resistivity) of 10 ² Ω · cm or more and 10 ¹¹ Ω · cm or less is desirably used. This is because the undercoat layer 1 needs to obtain an appropriate resistance for leak resistance and carrier block property acquisition. In addition, if the resistance value of the inorganic particles is lower than the lower limit of the above range, sufficient leakage resistance cannot be obtained, and if it is higher than the upper limit of this range, there is a concern that the residual potential is increased.

  Among these, inorganic particles such as tin oxide, titanium oxide, zinc oxide, and zirconium oxide are preferably used as the inorganic particles having the resistance value, and zinc oxide is particularly preferably used.

  Further, the inorganic particles may be subjected to a surface treatment, or may be used by mixing two or more kinds such as those having different surface treatments or particles having different particle diameters.

As the inorganic particles, those having a specific surface area of 10 m ² / g or more by the BET method are desirably used. Those having a specific surface area value of less than 10 m ² / g tend to cause a decrease in chargeability and tend to make it difficult to obtain good electrophotographic characteristics.

  Further, by incorporating inorganic particles and an acceptor compound, a product having excellent electrical properties for a long period of time and carrier blockability can be obtained. As the acceptor compound, any compound can be used as long as the desired characteristics can be obtained. However, quinone compounds such as chloranil and bromoanil, tetracyanoquinodimethane compounds, 2,4,7-trinitrofluorenone, Fluorenone compounds such as 2,4,5,7-tetranitro-9-fluorenone, 2- (4-biphenyl) -5- (4-tert-butylphenyl) -1,3,4-oxadiazole, and 2,5 Oxadiazole compounds such as -bis (4-naphthyl) -1,3,4-oxadiazole, 2,5-bis (4-diethylaminophenyl) 1,3,4-oxadiazole, xanthone compounds, Desirable are electron transport materials such as thiophene compounds and diphenoquinone compounds such as 3,3 ′, 5,5′tetra-t-butyldiphenoquinone. In particular compounds having an anthraquinone structure are preferable. Furthermore, acceptor compounds having an anthraquinone structure such as hydroxyanthraquinone compounds, aminoanthraquinone compounds, aminohydroxyanthraquinone compounds, and the like are desirably used, and specific examples include anthraquinone, alizarin, quinizarin, anthralfin, and purpurin.

  The content of these acceptor compounds may be arbitrarily set as long as desired characteristics are obtained, but is desirably 0.01% by mass or more and 20% by mass or less with respect to the inorganic particles. Furthermore, 0.05 mass% or more and 10 mass% or less are desirable from a viewpoint of preventing charge accumulation and preventing aggregation of inorganic particles. Aggregation of the inorganic particles tends to cause variations in the formation of the conductive path, which not only tends to cause deterioration in sustainability such as an increase in residual potential during repeated use, but also easily causes image quality defects such as black spots.

  The acceptor compound may be added only when the undercoat layer is applied, or may be previously attached to the surface of the inorganic particles. Examples of the method for imparting the acceptor compound to the surface of the inorganic particles include a dry method or a wet method.

  When surface treatment is performed by a dry method, dispersion is caused by dropping an acceptor compound dissolved in an organic solvent directly or with dry air or nitrogen gas while stirring inorganic particles with a mixer having a large shearing force. Processed without occurring. The addition or spraying is preferably performed at a temperature below the boiling point of the solvent. When spraying at a temperature equal to or higher than the boiling point of the solvent, the solvent evaporates before stirring without causing variation, and the acceptor compound is locally concentrated, which makes it difficult to perform processing without variation. After addition or spraying, baking may be performed at 100 ° C. or higher. Baking is carried out in an arbitrary range as long as the temperature and time allow the desired electrophotographic characteristics to be obtained.

  As a wet method, the inorganic particles are dispersed in a solvent using stirring, ultrasonic waves, a sand mill, an attritor, a ball mill, etc., added with an acceptor compound, stirred or dispersed, and then the solvent is removed without causing variations. It is processed. The solvent removal method is distilled off by filtration or distillation. After removing the solvent, baking may be performed at 100 ° C. or higher. Baking is carried out in an arbitrary range as long as the temperature and time allow the desired electrophotographic characteristics to be obtained. In the wet method, water containing inorganic particles can also be removed before adding the surface treatment agent. For example, a method of removing with stirring and heating in a solvent used for the surface treatment, a method of removing by azeotropic distillation with the solvent May be used.

  In addition, the inorganic particles may be subjected to a surface treatment before the acceptor compound is provided. The surface treatment agent is not particularly limited as long as it has desired characteristics and is selected from known materials. For example, a silane coupling agent, a titanate coupling agent, an aluminum coupling agent, a surfactant, and the like can be given. In particular, silane coupling agents are desirably used because they provide good electrophotographic properties. Further, a silane coupling agent having an amino group is desirably used because it gives the undercoat layer 1 good blocking properties.

  Any silane coupling agent having an amino group may be used as long as the desired electrophotographic photoreceptor characteristics can be obtained. Specific examples include γ-aminopropyltriethoxysilane, N-β-. (Aminoethyl) -γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropylmethylmethoxysilane, N, N-bis (β-hydroxyethyl) -γ-aminopropyltriethoxysilane, etc. However, it is not limited to these.

  Two or more silane coupling agents may be mixed and used. Examples of the silane coupling agent that may be used in combination with the silane coupling agent having an amino group include vinyltrimethoxysilane, γ-methacryloxypropyl-tris (β-methoxyethoxy) silane, β- (3, 4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, vinyltriacetoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β- (aminoethyl)- γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropylmethylmethoxysilane, N, N-bis (β-hydroxyethyl) -γ-aminopropyltriethoxysilane, γ-chloropropyltri Methoxysilane, etc. Not intended to be.

  As the surface treatment method, any known method can be used, but a dry method or a wet method is preferably used. Moreover, you may perform surface treatment by acceptor provision and a coupling agent etc. simultaneously.

  The amount of the silane coupling agent relative to the inorganic particles in the undercoat layer 1 is arbitrarily set as long as the desired electrophotographic characteristics can be obtained, but from the viewpoint of improving dispersibility, 0.5 mass with respect to the inorganic particles. % To 10% by mass is desirable.

  As the binder resin contained in the undercoat layer 1, any known resin can be used as long as it can form a good film and can obtain desired characteristics. For example, polyvinyl butyral, etc. Acetal resin, 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-vinyl acetate-maleic anhydride resin, Known polymer resin compounds such as silicone resins, silicone-alkyd resins, phenol resins, phenol-formaldehyde resins, melamine resins, urethane resins, charge transport resins having charge transport groups, and conductive resins such as polyaniline, etc. Used. Among these, resins that are insoluble in the upper coating solvent are preferably used, and phenol resins, phenol-formaldehyde resins, melamine resins, urethane resins, epoxy resins, and the like are particularly preferable. When these are used in combination of two or more, the mixing ratio is set as necessary.

  The ratio of the metal oxide to which the acceptor property is imparted in the coating solution for forming the undercoat layer and the binder resin, or the inorganic particles and the binder resin is arbitrarily set within a range in which desired electrophotographic photoreceptor characteristics can be obtained.

  Various additives may be used in the undercoat layer 1 in order to improve electrical characteristics, environmental stability, and image quality. As additives, known materials such as polycyclic condensation type, azo type electron transporting pigments, zirconium chelate compounds, titanium chelate compounds, aluminum chelate compounds, titanium alkoxide compounds, organic titanium compounds, silane coupling agents, and the like are used. It is done. The silane coupling agent is used for the surface treatment of the metal oxide, but may be further added to the coating solution as an additive. Specific examples of the silane coupling agent used here include vinyltrimethoxysilane, γ-methacryloxypropyl-tris (β-methoxyethoxy) silane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ- Glycidoxypropyltrimethoxysilane, vinyltriacetoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β- (Aminoethyl) -γ-aminopropylmethylmethoxysilane, N, N-bis (β-hydroxyethyl) -γ-aminopropyltriethoxysilane, γ-chloropropyltrimethoxysilane and the like. Examples of zirconium chelate compounds include zirconium butoxide, zirconium zirconium acetoacetate, zirconium triethanolamine, acetylacetonate zirconium butoxide, ethyl acetoacetate butoxide, zirconium acetate, zirconium oxalate, zirconium lactate, zirconium phosphonate, zirconium octoate, naphthene. Zirconate, zirconium laurate, zirconium stearate, zirconium isostearate, methacrylate zirconium butoxide, stearate zirconium butoxide, isostearate zirconium butoxide and the like.

Examples of titanium chelate compounds include tetraisopropyl titanate, tetranormal butyl titanate, butyl titanate dimer, tetra (2-ethylhexyl) titanate, titanium acetylacetonate, polytitanium acetylacetonate, titanium octylene glycolate, titanium lactate ammonium salt, Examples thereof include titanium lactate, titanium lactate ethyl ester, titanium triethanolamate, and polyhydroxytitanium stearate.

Examples of the aluminum chelate compound include aluminum isopropylate, monobutoxy aluminum diisopropylate, aluminum butyrate, diethyl acetoacetate aluminum diisopropylate, aluminum tris (ethyl acetoacetate) and the like.

  These compounds may be used alone or as a mixture or polycondensate of a plurality of compounds.

  As a solvent for adjusting the coating solution for forming the undercoat layer, any known organic solvent such as alcohol, aromatic, halogenated hydrocarbon, ketone, ketone alcohol, ether, ester, etc. Selected. Examples of the solvent include methanol, ethanol, n-propanol, iso-propanol, n-butanol, benzyl alcohol, methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, ethyl acetate, n-butyl acetate, Usual organic solvents such as dioxane, tetrahydrofuran, methylene chloride, chloroform, chlorobenzene and toluene are used.

  Moreover, you may use the solvent used for these dispersion | distribution individually or in mixture of 2 or more types. When mixing, any solvent can be used as long as it can dissolve the binder resin as the mixed solvent.

  As a dispersion method, known methods such as a roll mill, a ball mill, a vibration ball mill, an attritor, a sand mill, a colloid mill, and a paint shaker can be used. Further, as the coating method used when the undercoat layer 1 is provided, conventional methods such as blade coating method, wire bar coating method, spray coating method, dip coating method, bead coating method, air knife coating method, curtain coating method, etc. Is used.

  The undercoat layer 1 is formed on the conductive substrate using the undercoat layer-forming coating solution thus obtained.

The undercoat layer 1 preferably has a Vickers strength of 35 or more.
Furthermore, the undercoat layer 1 is set to any thickness as long as desired characteristics can be obtained. The thickness is preferably 15 μm or more, and more preferably 15 μm or more and 50 μm or less.

  When the thickness of the undercoat layer 1 is less than 15 μm, sufficient leakage resistance cannot be obtained, and when it is 50 μm or more, residual potential tends to remain when used for a long period of time, so that it tends to cause an abnormal image density. There are drawbacks.

  Further, the surface roughness (ten-point average roughness) of the undercoat layer 1 is from 1 / 4n (n is the refractive index of the upper layer) to 1 / 2λ of the exposure laser wavelength λ used to prevent moire images. Adjusted to In order to adjust the surface roughness, particles such as a resin may be added to the undercoat layer. As the resin particles, silicone resin particles, cross-linked polymethyl methacrylate resin particles, and the like are used.

  Further, the undercoat layer may be polished for adjusting the surface roughness. As a polishing method, buffing, sandblasting, wet honing, grinding, or the like can be used.

  The applied layer is dried to obtain an undercoat layer. Usually, the drying is performed at a temperature at which the solvent can be evaporated to form a film.

<Charge generation layer>
The charge generation layer 2 is a layer containing a charge generation material and a binder resin.
Examples of the charge generation material include azo pigments such as bisazo and trisazo, condensed aromatic pigments such as dibromoanthanthrone, perylene pigments, pyrrolopyrrole pigments, phthalocyanine pigments, zinc oxide, and trigonal selenium. Among these, metal and metal-free phthalocyanine pigments are desirable for near-infrared laser exposure. In particular, hydroxygallium phthalocyanine disclosed in JP-A-5-263007, JP-A-5-279591, and the like. Chlorogallium phthalocyanine disclosed in JP-A-5-98181, dichlorotin phthalocyanine disclosed in JP-A-5-140472, JP-A-5-140473, etc., JP-A-4-189873, More preferred is titanyl phthalocyanine disclosed in Kaihei 5-43823. For near-ultraviolet laser exposure, condensed aromatic pigments such as dibromoanthanthrone, thioindigo pigments, porphyrazine compounds, zinc oxide, and trigonal selenium are more desirable.

The binder resin used for the charge generation layer 2 is selected from a wide range of insulating resins, and selected from organic photoconductive polymers such as poly-N-vinylcarbazole, polyvinylanthracene, polyvinylpyrene, and polysilane. Also good. Desirable binder resins include polyvinyl butyral resins, polyarylate resins (polycondensates of bisphenols and aromatic divalent carboxylic acids, etc.), polycarbonate resins, polyester resins, phenoxy resins, vinyl chloride-vinyl acetate copolymers, polyamides. Resins, acrylic resins, polyacrylamide resins, polyvinyl pyridine resins, cellulose resins, urethane resins, epoxy resins, caseins, polyvinyl alcohol resins, polyvinyl pyrrolidone resins, and the like. These binder resins are used singly or in combination of two or more. The blending ratio of the charge generation material and the binder resin is preferably in the range of 10: 1 to 1:10 by mass ratio. Here, “insulating” means here that “insulating” means that the volume resistivity is 10 ¹³ Ωcm or more.

  The charge generation layer 2 is formed using a coating solution in which the charge generation material and the binder resin are dispersed in a predetermined solvent.

  Solvents used for dispersion 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, and methylene chloride. , Chloroform, chlorobenzene, toluene and the like. These may be used alone or in admixture of two or more.

  In addition, as a method for dispersing the charge generating material and the binder resin in the solvent, usual methods such as a ball mill dispersion method, an attritor dispersion method, and a sand mill dispersion method can be used. By these dispersion methods, changes in the crystal form of the charge generation material due to dispersion are prevented. Further, at the time of dispersion, it is effective that the average particle size of the charge generating material is 0.5 μm or less, desirably 0.3 μm or less, and more desirably 0.15 μm or less.

  Further, when forming the charge generation layer 2, a usual method such as a blade coating method, a Meyer 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 is used. .

The film thickness of the charge generation layer 2 obtained in this way is desirably 0.1 μm or more and 5.0 μm or less, and more desirably 0.2 μm or more and 2.0 μm or less.

<Charge transport layer>
The charge transport layer 3 is formed containing a charge transport material and a binder resin, or containing a polymer charge transport material.
Examples of charge transport materials include quinone compounds such as p-benzoquinone, chloranil, bromanyl, anthraquinone, tetracyanoquinodimethane compounds, fluorenone compounds such as 2,4,7-trinitrofluorenone, xanthone compounds, benzophenone compounds Electron transporting compounds such as cyanovinyl compounds and ethylene compounds, triarylamine compounds, benzidine compounds, arylalkane compounds, aryl-substituted ethylene compounds, stilbene compounds, anthracene compounds, hydrazone compounds, etc. Examples thereof include pore-transporting compounds. These charge transport materials may be used alone or in combination of two or more, but are not limited thereto.

  As the charge transport material, from the viewpoint of charge mobility, a triarylamine derivative represented by the following structural formula (a-1) and a benzidine derivative represented by the following structural formula (a-2) are desirable.

(In Structural Formula (a-1), R ⁸ represents a hydrogen atom or a methyl group. N represents 1 or 2. Ar ⁶ and Ar ⁷ are each independently a substituted or unsubstituted aryl group, —C _6. H ₄ —C (R ⁹ ) ═C (R ¹⁰ ) (R ¹¹ ), or —C ₆ H ₄ —CH═CH—CH═C (R ¹² ) (R ¹³ ), wherein R ^{9 to} R ¹³ are Each independently represents a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group, including a halogen atom, an alkyl group having 1 to 5 carbon atoms, and an alkoxy group having 1 to 5 carbon atoms; A substituted amino group substituted with a group or an alkyl group having 1 to 3 carbon atoms.)

(In Structural Formula (a-2), R ¹⁴ and R ^{14 ′} may be the same or different, and each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, or 1 to 5 carbon atoms. R ¹⁵ , R ^{15 ′} , R ¹⁶ , and R ^{16 ′} may be the same or different and each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, or 1 carbon atom. Or more, an alkoxy group having 5 or less, an amino group substituted with an alkyl group having 1 to 2 carbon atoms, a substituted or unsubstituted aryl group, -C (R ¹⁷ ) = C (R ¹⁸ ) (R ¹⁹ ), or- CH = CH—CH═C (R ²⁰ ) (R ²¹ ), wherein R ^{17 to} R ²¹ each independently represents a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group. And n are each independently 0 or more and 2 It represents an integer of below.)

Here, triarylamine derivatives represented by the structural formula (a-1), and among the benzidine derivative represented by the above formula (a-2), in particular, _{"- C 6 H 4 -CH = CH} -CH ═C (R ¹² ) (R ¹³ ) ”and a benzidine derivative having“ —CH═CH—CH═C (R ²⁰ ) (R ²¹ ) ”have charge mobility, protective layer and It is excellent and desirable from the standpoints of adhesiveness and afterimage (hereinafter sometimes referred to as “ghost”) caused by the history of the previous image remaining.

  The binder resin used for the charge transport layer 3 is polycarbonate resin, polyester resin, polyarylate resin, methacrylic resin, acrylic resin, polyvinyl chloride resin, polyvinylidene chloride resin, polystyrene resin, polyvinyl acetate resin, styrene-butadiene copolymer. , Vinylidene chloride-acrylonitrile copolymer, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate-maleic anhydride copolymer, silicone resin, silicone alkyd resin, phenol-formaldehyde resin, styrene-alkyd resin, poly- N-vinyl carbazole, polysilane, etc. are mentioned. Further, as described above, polymer charge transport materials such as polyester-based polymer charge transport materials disclosed in JP-A-8-176293 and JP-A-8-208820 may be used. These binder resins are used singly or in combination of two or more. The blending ratio of the charge transport material and the binder resin is desirably 10: 1 to 1: 5 by mass ratio.

  In addition, a polymer charge transport material may be used as the charge transport material. As the polymer charge transporting material, known materials having charge transporting properties such as poly-N-vinylcarbazole and polysilane are used. In particular, polyester polymer charge transport materials disclosed in JP-A-8-176293, JP-A-8-208820 and the like have a higher charge transportability than other types, and are particularly desirable. is there. The polymer charge transport material can be formed by itself, but may be formed by mixing with a binder resin described later.

  The charge transport layer 3 is formed using a charge transport layer forming coating solution containing the above-described constituent materials. Solvents used in the coating solution for forming the charge transport layer include aromatic hydrocarbons such as benzene, toluene, xylene and chlorobenzene, ketones such as acetone and 2-butanone, and halogenation such as methylene chloride, chloroform and ethylene chloride. Ordinary organic solvents such as aliphatic hydrocarbons, cyclic ethers such as tetrahydrofuran and ethyl ether or linear ethers may be used alone or in combination of two or more. Moreover, a well-known method is used as a dispersion method of each said constituent material.

  The coating method for applying the charge transport layer forming coating solution onto the charge generation layer 2 includes blade coating method, Mayer bar coating method, spray coating method, dip coating method, bead coating method, air knife coating method, A usual method such as a curtain coating method is used.

  The film thickness of the charge transport layer 3 is desirably 5 μm or more and 50 μm or less, and more desirably 10 μm or more and 30 μm or less.

<Protective layer>
The protective layer 5 is the outermost surface layer in the electrophotographic photosensitive member 7 and is a layer provided in order to give resistance to abrasion and scratches on the outermost surface and to increase toner transfer efficiency.

The protective layer 5 is cross-linked using a guanamine compound and at least one charge transporting material having at least one substituent selected from —OH, —OCH ₃ , —NH ₂ , —SH, and —COOH. It is composed of things. First, the guanamine compound will be described.

  Examples of the guanamine compound include acetoguanamine, benzoguanamine, formoguanamine, steroguanamine, spiroguanamine, cyclohexylguanamine and the like.

  The guanamine compound is particularly preferably at least one of a compound represented by the following general formula (A) and a multimer thereof. Here, the multimer is an oligomer polymerized using the compound represented by the general formula (A) as a structural unit, and the degree of polymerization thereof is, for example, 2 or more and 200 or less (preferably 2 or more and 100 or less). The compound represented by the general formula (A) may be used alone or in combination of two or more. In particular, when the compound represented by the general formula (A) is used as a mixture of two or more kinds, or used as a multimer (oligomer) having the structural unit as a structural unit, the solubility in a solvent is improved.

In general formula (A), R ₁ is a linear or branched alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted phenyl group having 6 to 10 carbon atoms, or 4 to 10 carbon atoms. The following substituted or unsubstituted alicyclic hydrocarbon groups are shown. R _{2 to} R ₅ each independently represent hydrogen, —CH ₂ —OH, or —CH ₂ —O—R ₆ . R ₆ represents hydrogen or a linear or branched alkyl group having 1 to 10 carbon atoms.

In the general formula (A), the alkyl group representing R ₁ has 1 to 10 carbon atoms, preferably 1 to 8 carbon atoms, more preferably 1 to 5 carbon atoms. . The alkyl group may be linear or branched.

In general formula (A), the phenyl group represented by R ₁ has 6 to 10 carbon atoms, and more preferably 6 to 8 carbon atoms. Examples of the substituent substituted with the phenyl group include a methyl group, an ethyl group, and a propyl group.

In general formula (A), the alicyclic hydrocarbon group representing R ₁ has 4 to 10 carbon atoms, and more preferably 5 to 8 carbon atoms. Examples of the substituent substituted with the alicyclic hydrocarbon group include a methyl group, an ethyl group, and a propyl group.

In the general formula (A), in “—CH ₂ —O—R ₆ ” representing R _{2 to} R ₅ , the alkyl group representing R ₆ has 1 to 10 carbon atoms, and desirably has carbon atoms. 1 or less and 8 or more, and more preferably 1 or more and 6 or less. The alkyl group may be linear or branched. Preferably, a methyl group, an ethyl group, a butyl group, etc. are mentioned.

As the compound represented by the general formula (A), it is particularly desirable that R ₁ represents a substituted or unsubstituted phenyl group having 6 to 10 carbon atoms, and R _{2 to} R ₅ are each independently —CH ₂ —O. It is a compound represented by —R ₆ . R ₆ is preferably selected from a methyl group and an n-butyl group.

  The compound represented by the general formula (A) is synthesized by, for example, a known method using guanamine and formaldehyde (for example, Experimental Chemistry Course 4th Edition, Volume 28, page 430).

  Specific examples of the compound represented by the general formula (A) are shown below, but are not limited thereto. Moreover, although the following specific examples show the thing of a monomer, the multimer (oligomer) which uses these as a structural unit may be sufficient.

  Commercially available products of the compound represented by the general formula (A) include, for example, “Superbecamine (R) L-148-55, Superbecamine (R) 13-535, Superbecamine (R) L-145- 60, Superbecamine (R) TD-126 "manufactured by Dainippon Ink Co., Ltd.," Nicarac BL-60, Nicarac BX-4000 "manufactured by Nippon Carbide, and the like.

  In addition, the compound represented by the general formula (A) is dissolved in an appropriate solvent such as toluene, xylene, ethyl acetate or the like after the synthesis or after purchase of a commercially available product in order to remove the influence of the residual catalyst. It may be washed with ion exchange water or the like, or may be removed by treatment with an ion exchange resin.

Next, a specific charge transport material will be described. As the specific charge transporting material, for example, a material having at least one substituent selected from —OH, —OCH ₃ , —NH ₂ , —SH, and —COOH is preferably exemplified. In particular, specific charge transporting materials preferably include those having at least three substituents selected from —OH, —OCH ₃ , —NH ₂ , —SH, and —COOH. As described above, by increasing the reactive functional group (substituent) in a specific charge transporting material, the crosslink density is increased and a cross-linked film having higher strength can be obtained. In particular, electrophotographic photosensitive when using a blade cleaner is used. The rotational torque of the body is reduced, and the damage to the blade is suppressed and the wear of the electrophotographic photosensitive member is suppressed. Although the details are unknown, since a cured film having a high crosslinking density can be obtained by increasing the number of reactive functional groups, the molecular motion of the extreme surface of the electrophotographic photosensitive member is suppressed, so that It is presumed that this interaction weakens.

The specific charge transporting material is preferably a compound represented by the following general formula (I).
_{F - ((- R 7 -X} ) n1 R 8 -Y) n2 (I)

In general formula (I), F is an organic group derived from a compound having a hole transporting ability, R ₇ and R ₈ are each independently a linear or branched alkylene group having 1 to 5 carbon atoms. N1 represents 0 or 1, and n2 represents an integer of 1 or more and 4 or less. X represents an oxygen, NH, or sulfur atom, and Y represents —OH, —OCH ₃ , —NH ₂ , —SH, or —COOH.

  In general formula (I), an arylamine derivative is preferably used as the compound having a hole transporting ability in an organic group derived from a compound having a hole transporting ability represented by F. Preferred examples of the arylamine derivative include a triphenylamine derivative and a tetraphenylbenzidine derivative.

  The compound represented by the general formula (I) is preferably a compound represented by the following general formula (II). The compound represented by the general formula (II) is particularly excellent in charge mobility, stability against oxidation and the like.

In general formula (II), Ar ^{1 to} Ar ⁴ may be the same or different and each independently represents a substituted or unsubstituted aryl group, and Ar ⁵ represents a substituted or unsubstituted aryl group or substituted or unsubstituted. D represents — (— R ₇ —X) _n1 R ₈ —Y, c represents 0 or 1 independently, k represents 0 or 1, and the total number of D is 1 or more and 4 It is as follows. R ₇ and R ₈ each independently represents a linear or branched alkylene group having 1 to 5 carbon atoms, n1 represents 0 or 1, X represents an oxygen, NH, or sulfur atom. , Y represents —OH, —OCH ₃ , —NH ₂ , —SH, or —COOH.

In the general formula (II), “— (— R ₇ —X) _n1 R ₈ —Y” representing D is the same as in the general formula (I), and R ₇ and R ₈ each independently have 1 or more carbon atoms. It is a linear or branched alkylene group of 5 or less. N1 is preferably 1. X is preferably oxygen. Y is preferably a hydroxyl group.
The total number of D in the general formula (II) corresponds to n2 in the general formula (I), preferably 2 or more and 4 or less, and more preferably 3 or more and 4 or less. That is, in the general formula (I) and the general formula (II), when the molecular weight is desirably 2 or more and 4 or less, more desirably 3 or more and 4 or less in one molecule, the crosslinking density increases and a crosslinked film with higher strength can be obtained. In particular, the rotational torque of the electrophotographic photosensitive member when using a blade cleaner is reduced, so that damage to the blade and wear of the electrophotographic photosensitive member are suppressed. Details of this are unknown, but by increasing the number of reactive functional groups, a cured film with a high crosslink density can be obtained, and molecular motion on the extreme surface of the electrophotographic photoreceptor is suppressed, allowing mutual interaction with the blade member surface molecules. It is presumed that the action is weakened.

In general formula (II), Ar _{1 to} Ar ₄ are preferably any of the following formulas (1) to (7). Incidentally, the following equation (1) to (7) can be coupled to each Ar ₁ to Ar ₄ - shown with _{"(D) C".}

In Formulas (1) and (2), R ⁹ is a phenyl substituted with a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms. Represents one selected from the group consisting of a group, an unsubstituted phenyl group, and an aralkyl group having 7 to 10 carbon atoms, wherein R ^{10 to} R ¹² are a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, and a carbon number, respectively. One selected from the group consisting of an alkoxy group having 1 to 4 carbon atoms, a phenyl group substituted with an alkoxy group having 1 to 4 carbon atoms, an unsubstituted phenyl group, an aralkyl group having 7 to 10 carbon atoms, and a halogen atom Ar represents a substituted or unsubstituted arylene group, D and C are the same as “D” and “c” in formula (II), s represents 0 or 1, and t is 1 or more, respectively. Integer less than 3 Represent. ]

  Here, as Ar in Formula (7), what is represented by following formula (8) or (9) is desirable.

[In formulas (8) and (9), R ¹³ and R ¹⁴ are each a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms. 1 represents one selected from the group consisting of a phenyl group substituted with, an unsubstituted phenyl group, an aralkyl group having 7 to 10 carbon atoms and a halogen atom, and t represents an integer of 1 to 3. ]

  Further, Z ′ in the formula (7) is preferably represented by any one of the following formulas (10) to (17).

[In the formulas (10) to (17), R ¹⁵ and R ¹⁶ are each a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms. Represents a phenyl group substituted with, an unsubstituted phenyl group, an aralkyl group having 7 to 10 carbon atoms, and a halogen atom, W represents a divalent group, q and r each represent Represents an integer of 1 to 10, and t represents an integer of 1 to 3. ]

  W in the formulas (16) to (17) is preferably any one of divalent groups represented by the following (18) to (26). However, in formula (25), u represents an integer of 0 or more and 3 or less.

In general formula (II), Ar ⁵ is an aryl group exemplified in the description of Ar ^{1 to} Ar ⁴ when k is 0, and when k is 1, a predetermined hydrogen atom is taken from the aryl group. Excluded arylene group

  Specific examples of the compound represented by the general formula (I) include the following compounds (I) -1 to (I) -34. In addition, the compound shown by the said general formula (I) is not limited at all by these.

  Here, the ratio between the guanamine compound (the compound represented by the general formula (A)) and the specific charge transporting material (the compound represented by the general formula (I)) is guanamine from the viewpoint of electrical characteristics and strength. The specific charge transporting material is desirably 0.2 parts by mass or more and 4 parts by mass or less, more desirably 0.3 parts by mass or more and 3 parts by mass or less, and further desirably, relative to 1 part by mass of the compound. Is 0.4 parts by mass or more and 2 parts by mass or less.

  The guanamine compound (compound represented by the general formula (A)) is preferably used in an amount of 10% by mass to 80% by mass, more preferably 15% by mass to 70% by mass, based on the entire layer constituent material. More desirably, it is 20 mass% or more and 65 mass% or less.

Hereinafter, the protective layer 5 will be described in more detail.
The protective layer 5 includes a cross-linked product of a guanamine compound (a compound represented by the general formula (A)) and a specific charge transporting material (a compound represented by the general formula (I)), a phenol resin, a melamine resin, and urea. You may mix and use resin, an alkyd resin, etc. Further, in order to improve the strength, a compound having more functional groups in one molecule such as spiroacetal guanamine resin (for example, “CTU-guanamine” (Ajinomoto Fine Techno Co., Ltd.)) is used as the material in the crosslinked product. Copolymerization is also effective.

In addition, other heat such as phenol resin, melamine resin, and benzoguanamine resin is added to the protective layer 5 for the purpose of effectively suppressing oxidation by the discharge generated gas by adding so as not to absorb the discharge generated gas excessively. A curable resin may be mixed and used.

  Further, the protective layer 5 may be used in combination with another coupling agent or a fluorine compound for the purpose of adjusting the film formability, flexibility, lubricity, and adhesiveness of the film. As this compound, various silane coupling agents and commercially available silicone hard coat agents are used.

  As the silane coupling agent, vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropylmethyldimethoxysilane, N-β (aminoethyl) γ-aminopropyltriethoxysilane, tetramethoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, and the like are used. As a commercially available hard coat agent, KP-85, X-40-9740, X-8239 (manufactured by Shin-Etsu Silicone), AY42-440, AY42-441, AY49-208 (manufactured by Toray Dow Corning) Etc. are used. In order to impart water repellency and the like, (tridecafluoro-1,1,2,2-tetrahydrooctyl) triethoxysilane, (3,3,3-trifluoropropyl) trimethoxysilane, 3- (hepta) Fluoroisopropoxy) propyltriethoxysilane, 1H, 1H, 2H, 2H-perfluoroalkyltriethoxysilane, 1H, 1H, 2H, 2H-perfluorodecyltriethoxysilane, 1H, 1H, 2H, 2H-perfluorooctyl Fluorine-containing compounds such as triethoxysilane may be added. Although the silane coupling agent is used in an arbitrary amount, the amount of the fluorine-containing compound is desirably 0.25 times or less by mass with respect to the compound not containing fluorine. If this amount is exceeded, there may be a problem with the film formability of the crosslinked film.

  Moreover, you may add resin which melt | dissolves in alcohol for the purpose of discharge gas resistance of the protective layer 5, mechanical strength, scratch resistance, particle dispersibility, viscosity control, torque reduction, wear amount control, pot life extension, and the like.

  Here, the alcohol-soluble resin means a resin that can be dissolved by 1 mass% or more in an alcohol having 5 or less carbon atoms. Examples of resins that are soluble in alcohol solvents include polyvinyl acetal resins such as polyvinyl butyral resin, polyvinyl formal resin, and partially acetalized polyvinyl acetal resin in which a part of butyral is modified with formal or acetoacetal (for example, manufactured by Sekisui Chemical Co., Ltd.) ESREC B, K, etc.), polyamide resin, cellulose resin, polyvinylphenol resin and the like. In particular, polyvinyl acetal resin and polyvinyl phenol resin are desirable in terms of electrical characteristics. The resin preferably has a weight average molecular weight of 2,000 to 100,000, and more preferably 5,000 to 50,000. If the molecular weight of the resin is less than 2,000, the effect due to the addition of the resin tends to be insufficient, and if it exceeds 100,000, the solubility is reduced and the addition amount is limited. It tends to cause defects. The amount of the resin added is preferably 1% by mass or more and 40% by mass or less, more preferably 1% by mass or more and 30% by mass or less, and further preferably 5% by mass or more and 20% by mass or less. If the addition amount of the resin is less than 1% by mass, the effect of the addition of the resin tends to be insufficient. If the addition amount exceeds 40% by mass, the temperature is high under high humidity (for example, 28 ° C., 85% RH). Image blur is likely to occur.

  It is desirable to add an antioxidant to the protective layer 5 for the purpose of preventing deterioration due to an oxidizing gas such as ozone generated in the charging device. When the mechanical strength of the surface of the photoconductor is increased and the photoconductor has a long life, the photoconductor is in contact with the oxidizing gas for a long time, and therefore, stronger oxidation resistance is required than before. Antioxidants are preferably hindered phenols or hindered amines, organic sulfur antioxidants, phosphite antioxidants, dithiocarbamate antioxidants, thiourea antioxidants, benzimidazole antioxidants. , Etc., may be used. The addition amount of the antioxidant is preferably 20% by mass or less, and more preferably 10% by mass or less.

  Examples of the hindered phenol antioxidant include 2,6-di-t-butyl-4-methylphenol, 2,5-di-t-butylhydroquinone, N, N′-hexamethylene bis (3,5-di). -T-butyl-4-hydroxyhydrocinnamide, 3,5-di-t-butyl-4-hydroxy-benzylphosphonate-diethyl ester, 2,4-bis [(octylthio) methyl] -o-cresol, 2,6-di-t-butyl-4-ethylphenol, 2,2'-methylenebis (4-methyl-6-t-butylphenol), 2,2'-methylenebis (4-ethyl-6-t-butylphenol) 4,4'-butylidenebis (3-methyl-6-t-butylphenol), 2,5-di-t-amylhydroquinone, 2-t-butyl-6- (3-butyl-2- Dorokishi-5-methylbenzyl) -4-methylphenyl acrylate, 4,4'-butylidene bis (3-methyl -6-t-butylphenol) and the like.

  Furthermore, various particles may be added to the protective layer 5 for the purpose of lowering the residual potential or improving the strength. An example of the particles is silicon-containing particles. The silicon-containing particles are particles containing silicon as a constituent element, and specific examples include colloidal silica and silicone particles. Colloidal silica used as silicon-containing particles is prepared by dispersing silica having an average particle size of 1 nm to 100 nm, preferably 10 nm to 30 nm in an organic solvent such as an acidic or alkaline aqueous dispersion, alcohol, ketone, or ester. A commercially available product may be used. The solid content of colloidal silica in the protective layer 5 is not particularly limited, but 0.1% based on the total solid content of the protective layer 5 in terms of film forming properties, electrical characteristics, and strength. It is used in the range of mass% to 50 mass%, desirably 0.1 mass% to 30 mass%.

  The silicone particles used as the silicon-containing particles are selected from silicone resin particles, silicone rubber particles, and silicone surface-treated silica particles, and those commercially available are generally used. These silicone particles are spherical, and the average particle size is desirably 1 nm or more and 500 nm or less, and more desirably 10 nm or more and 100 nm or less. Silicone particles are small particles that are chemically inert and excellent in dispersibility in resins, and since the content required to obtain more sufficient properties is low, the crosslinking reaction is not hindered. The surface properties of the photographic photoreceptor are improved. In other words, it is improved in lubricity and water repellency on the surface of the electrophotographic photosensitive member in a state of being taken in without a variation in a strong cross-linked structure, and has good wear resistance and contamination resistance adhesion over a long period of time. Maintained. The content of the silicone particles in the protective layer 5 is desirably 0.1% by mass or more and 30% by mass or less, more desirably 0.5% by mass or more and 10% by mass or less, based on the total amount of the total solid content of the protective layer 5. It is.

Other particles include fluorine-based particles such as ethylene tetrafluoride, ethylene trifluoride, propylene hexafluoride, vinyl fluoride, vinylidene fluoride, and “8th Polymer Material Forum Lecture Proceedings p89”. As shown, particles made of a resin obtained by copolymerizing a fluororesin and a monomer having a hydroxyl group, ZnO—Al ₂ O ₃ , SnO ₂ —Sb ₂ O ₃ , In ₂ O ₃ —SnO ₂ , ZnO ₂ —TiO ₂ , ZnO Examples thereof include semiconductive metal oxides such as —TiO ₂ , MgO—Al ₂ O ₃ , FeO—TiO ₂ , TiO ₂ , SnO ₂ , In ₂ O ₃ , ZnO, and MgO. For the same purpose, an oil such as silicone oil may be added. Silicone oils include silicone oils such as dimethylpolysiloxane, diphenylpolysiloxane, and phenylmethylsiloxane; amino-modified polysiloxane, epoxy-modified polysiloxane, carboxyl-modified polysiloxane, carbinol-modified polysiloxane, methacryl-modified polysiloxane, mercapto-modified poly Reactive silicone oils such as siloxane and phenol-modified polysiloxane; cyclic dimethylcyclosiloxanes such as hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane and dodecamethylcyclohexasiloxane; 1,3,5- Trimethyl-1.3.5-triphenylcyclotrisiloxane, 1,3,5,7-tetramethyl-1,3,5,7-tetraphenylcyclo Cyclic methylphenylcyclosiloxanes such as trasiloxane, 1,3,5,7,9-pentamethyl-1,3,5,7,9-pentaphenylcyclopentasiloxane; cyclic phenylcyclosiloxanes such as hexaphenylcyclotrisiloxane Fluorine-containing cyclosiloxanes such as (3,3,3-trifluoropropyl) methylcyclotrisiloxane; hydrosilyl group-containing cyclosiloxanes such as methylhydrosiloxane mixtures, pentamethylcyclopentasiloxane, and phenylhydrocyclosiloxane; penta And vinyl group-containing cyclosiloxanes such as vinylpentamethylcyclopentasiloxane.

  Further, a metal, metal oxide, carbon black, or the like may be added to the protective layer 5. Examples of the metal include aluminum, zinc, copper, chromium, nickel, silver, and stainless steel, or those obtained by depositing these metals on the surface of plastic particles. Examples of the metal oxide include zinc oxide, titanium oxide, tin oxide, antimony oxide, indium oxide, bismuth oxide, tin-doped indium oxide, antimony and tantalum-doped tin oxide, and antimony-doped zirconium oxide. . These may be used alone or in combination of two or more. When two or more types are used in combination, they may be simply mixed, or may be in the form of a solid solution or fusion. The average particle diameter of the conductive particles is preferably 0.3 μm or less, particularly preferably 0.1 μm or less, from the viewpoint of the transparency of the protective layer.

  In the protective layer 5, a curing catalyst may be used in order to accelerate the curing of the guanamine compound (the compound represented by the general formula (A)) or the charge transport material. An acid catalyst is preferably used as the curing catalyst. Acid-based catalysts include acetic acid, chloroacetic acid, trichloroacetic acid, trifluoroacetic acid, oxalic acid, maleic acid, malonic acid, lactic acid and other aliphatic carboxylic acids, benzoic acid, phthalic acid, terephthalic acid, trimellitic acid, etc. Aromatic carboxylic acids, methane sulfonic acids, dodecyl sulfonic acids, benzene sulfonic acids, aliphatics such as dodecyl benzene sulfonic acids, naphthalene sulfonic acids, and aromatic sulfonic acids are used, but sulfur-containing materials should be used. desirable.

  By using a sulfur-containing material as a curing catalyst, this sulfur-containing material exhibits an excellent function as a curing catalyst for guanamine compounds (compounds represented by the general formula (A)) and charge transport materials, and accelerates the curing reaction. Thus, the mechanical strength of the protective layer 5 obtained is further improved. Furthermore, when the compound represented by the general formula (I) (including the general formula (II)) is used as the charge transport material, the sulfur-containing material exhibits an excellent function as a dopant for these charge transport materials. In addition, the electrical characteristics of the obtained functional layer are further improved. As a result, when an electrophotographic photosensitive member is formed, all of mechanical strength, film formability, and electrical characteristics are achieved at a high level.

  The sulfur-containing material as a curing catalyst is preferably at room temperature (for example, 25 ° C.) or exhibits acidity after heating, and at least one of organic sulfonic acid and its derivatives is most preferable from the viewpoint of adhesiveness, ghost, and electrical characteristics. desirable. The presence of these catalysts in the protective layer 5 is easily confirmed by XPS or the like.

  Examples of the organic sulfonic acid and / or a derivative thereof include p-toluenesulfonic acid, dinonylnaphthalenesulfonic acid (DNNSA), dinonylnaphthalenedisulfonic acid (DNNDSA), dodecylbenzenesulfonic acid, and phenolsulfonic acid. Among these, paratoluenesulfonic acid and dodecylbenzenesulfonic acid are desirable from the viewpoint of catalytic ability and film formability. Further, an organic sulfonate may be used as long as it can be dissociated to some extent in the curable resin composition.

  In addition, by using a so-called thermal latent catalyst that increases the catalytic ability when a temperature above a certain level is applied, the catalytic ability is low at the liquid storage temperature and the catalytic ability is high at the time of curing. And storage stability.

  As a heat latent catalyst, for example, a microcapsule in which an organic sulfone compound or the like is encapsulated in a polymer form, an adsorbed acid or the like on a pore compound such as zeolite, and a proton acid and / or proton acid derivative is blocked with a base Thermal latent proton acid catalyst, proton acid and / or proton acid derivative esterified with primary or secondary alcohol, proton acid and / or proton acid derivative blocked with vinyl ethers and / or vinyl thioethers And boron trifluoride monoethylamine complex, boron trifluoride pyridine complex, and the like.

  Among them, a product obtained by blocking a protonic acid and / or a protonic acid derivative with a base in terms of catalytic ability, storage stability, availability, and cost is desirable.

  As the protonic acid of the heat latent protonic acid catalyst, sulfuric acid, hydrochloric acid, acetic acid, formic acid, nitric acid, phosphoric acid, sulfonic acid, monocarboxylic acid, polycarboxylic acids, propionic acid, oxalic acid, benzoic acid, acrylic acid, methacrylic acid, Itaconic acid, phthalic acid, maleic acid, benzenesulfonic acid, o, m, p-toluenesulfonic acid, styrenesulfonic acid, dinonylnaphthalenesulfonic acid, dinonylnaphthalenedisulfonic acid, decylbenzenesulfonic acid, undecylbenzenesulfonic acid, Examples include tridecylbenzenesulfonic acid, tetradecylbenzenesulfonic acid, dodecylbenzenesulfonic acid and the like. In addition, as protonic acid derivatives, neutralized products such as alkali metal salts of alkaline acids or alkaline earth metal circles such as sulfonic acid and phosphoric acid, and polymer compounds in which a protonic acid skeleton is introduced into the polymer chain (polyvinylsulfone) Acid, etc.). Examples of the base that blocks the protonic acid include amines.

  The amines are classified as primary, secondary or tertiary amines. There is no restriction in particular and any of them may be used.

  Examples of the primary amine include methylamine, ethylamine, propylamine, isopropylamine, n-butylamine, isobutylamine, t-butylamine, hexylamine, 2-ethylhexylamine, secondary butylamine, allylamine, and methylhexylamine.

  As secondary amines, dimethylamine, diethylamine, di-n-propylamine, diisopropylamine, di-n-butylamine, diisobutylamine, di-t-butylamine, dihexylamine, di (2-ethylhexyl) amine, N-isopropyl N-isobutylamine , Di (2-ethylhexyl) amine, disecondary butylamine, diallylamine, N-methylhexylamine, 3-pipecoline, 4-pipecoline, 2,4-lupetidine, 2,6-lupetidine, 3,5-lupetidine, morpholine, N -Methylbenzylamine and the like.

  As tertiary amines, trimethylamine, triethylamine, tri-n-propylamine, triisopropylamine, tri-n-butylamine, triisobutylamine, tri-t-butylamine, trihexylamine, tri (2-ethylhexyl) amine, N-methylmorpholine, N, N-dimethylallylamine, N-methyldiallylamine, triallylamine, N, N-dimethylallylamine, N, N, N ′, N′-tetramethyl-1,2-diaminoethane, N, N, N ′, N′-tetramethyl-1,3 -Diaminopropane, N, N, N ', N'-tetraallyl-1,4-diaminobutane, N-methylpiperidine, pyridine, 4-ethylpyridine, N-propyldiallylamine, 3-dimethylaminopropanol, 2-ethylpyrazine, 2, 3-di Tilpyrazine, 2,5-dimethylpyrazine, 2,4-lutidine, 2,5-lutidine, 3,4-lutidine, 3,5-lutidine, 2,4,6-collidine, 2-methyl-4-ethylpyridine, 2-methyl-5-ethylpyridine, N, N, N ′, N′-tetramethylhexamethylenediamine, N-ethyl-3-hydroxypiperidine, 3-methyl-4-ethylpyridine, 3-ethyl-4-methyl Pyridine, 4- (5-nonyl) pyridine, imidazole, N-methylpiperazine and the like can be mentioned.

  Commercially available products include “NACURE2501” (toluenesulfonic acid dissociation, methanol / isopropanol solvent, pH 6.0 to pH 7.2, dissociation temperature 80 ° C.), “NACURE2107” (p-toluenesulfonic acid dissociation, manufactured by King Industries, Inc. Isopropanol solvent, pH 8.0 to pH 9.0, dissociation temperature 90 ° C.) “NACURE 2500” (p-toluenesulfonic acid dissociation, isopropanol solvent, pH 6.0 to pH 7.0, dissociation temperature 65 ° C.), “NACURE 2530” (P-toluenesulfonic acid dissociation, methanol / isopropanol solvent, pH 5.7 to pH 6.5, dissociation temperature 65 ° C.), “NACURE2547” (p-toluenesulfonic acid dissociation, aqueous solution, pH 8.0 to pH 9.0, Dissociation temperature 107 ), “NACURE2558” (p-toluenesulfonic acid dissociation, ethylene glycol solvent, pH 3.5 to pH4.5, dissociation temperature 80 ° C.), “NACUREXP-357” (p-toluenesulfonic acid dissociation, methanol solvent, pH 2. 0 to pH 4.0, dissociation temperature 65 ° C.) “NACUREXP-386” (p-toluenesulfonic acid dissociation, aqueous solution, pH 6.1 to pH 6.4, dissociation temperature 80 ° C.), “NACUREX C-2211” (p -Toluenesulfonic acid dissociation, pH 7.2 to pH 8.5, dissociation temperature 80 ° C.), “NACURE 5225” (dodecylbenzenesulfonic acid dissociation, isopropanol solvent, pH 6.0 to pH 7.0, dissociation temperature 120 ° C.), “ NACURE 5414 "(dodecylbenzenesulfonic acid dissociation, key Ren solvent, dissociation temperature 120 ° C.), “NACURE 5528” (dodecylbenzenesulfonic acid dissociation, isopropanol solvent, pH 7.0 to pH 8.0, dissociation temperature 120 ° C.), “NACURE 5925” (dodecylbenzenesulfonic acid dissociation, pH 7.0) PH 7.5 or less, dissociation temperature 130 ° C., “NACURE 1323” (disinyl naphthalene sulfonic acid dissociation, xylene solvent, pH 6.8 to pH 7.5, dissociation temperature 150 ° C.), “NACURE 1419” (dinonyl naphthalene sulfonic acid Dissociation, xylene / methyl isobutyl ketone solvent, dissociation temperature 150 ° C.), “NACURE1557” (dinonylnaphthalenesulfonic acid dissociation, butanol / 2-butoxyethanol solvent, pH 6.5 to pH 7.5, dissociation temperature 150 ° C.), “ NA CUREX 49-110 ”(dinonyl naphthalene disulfonic acid dissociation, isobutanol / isopropanol solvent, pH 6.5 to pH 7.5, dissociation temperature 90 ° C.),“ NACURE 3525 ”(dinonyl naphthalene disulfonic acid dissociation, isobutanol / isopropanol solvent, pH 7.0 to pH 8.5, dissociation temperature 120 ° C., “NACUREXP-383” (dinonyl naphthalene disulfonic acid dissociation, xylene solvent, dissociation temperature 120 ° C.), “NACURE 3327” (dinonyl naphthalene disulfonic acid dissociation, isobutanol / Isopropanol solvent, pH 6.5 to pH 7.5, dissociation temperature 150 ° C.), “NACURE4167” (phosphoric acid dissociation, isopropanol / isobutanol solvent, pH 6.8 to pH 7.3, dissociation temperature 80 ), “NACUREXP-297” (phosphoric acid dissociation, water / isopropanol solvent, pH 6.5 to pH 7.5, dissociation temperature 90 ° C., “NACURE 4575” (phosphoric acid dissociation, pH 7.0 to pH 8.0, dissociation temperature) 110 ° C.).

  These thermal latent catalysts may be used alone or in combination of two or more.

  The blending amount of the heat-latent catalyst is preferably 0.01% by mass or more and 20% by mass or less, and particularly preferably 0.1% by mass or more and 10% by mass or less with respect to 100 parts by solid content in the resin solution. Yes. If the addition amount exceeds 20% by mass, it may precipitate as a foreign substance after the calcination treatment, and if it is less than 0.01% by mass, the catalytic activity becomes low.

  The protective layer 5 having the above configuration is formed using a coating liquid for film formation containing at least the guanamine compound (the compound represented by the general formula (A)) and at least one of the specific charge transporting materials. . In the coating liquid for film formation, the constituent components of the protective layer 5 are added as necessary.

  The coating solution for film formation is prepared without a solvent or, if necessary, alcohols such as methanol, ethanol, propanol and butanol; ketones such as acetone and methyl ethyl ketone; ethers such as tetrahydrofuran, diethyl ether and dioxane. You may carry out using solvents, such as. Such solvents can be used singly or in combination of two or more, and preferably have a boiling point of 100 ° C. or lower. As the solvent, it is particularly preferable to use a solvent having at least one hydroxyl group (for example, alcohol).

  The amount of the solvent is arbitrarily set, but if it is too small, the guanamine compound (compound represented by the general formula (A)) is likely to be precipitated, so that 1 part by weight of the guanamine compound (compound represented by the general formula (A)). On the other hand, it is used in an amount of 0.5 to 30 parts by mass, preferably 1 to 20 parts by mass.

  In addition, when the coating liquid is obtained by reacting the above components, it may be simply mixed and dissolved, but it is room temperature (for example, 25 ° C.) to 100 ° C., preferably 30 ° C. to 80 ° C. for 10 minutes to 100 Heating may be performed for a period of time or less, preferably 1 hour or more and 50 hours or less. It is also desirable to irradiate ultrasonic waves at this time. Thereby, it is likely that a partial reaction proceeds, and it is easy to obtain a film having no coating film defects and little variation in film thickness.

  Then, a coating solution for forming a film is formed on the charge transport layer 3 by a usual method such as 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 method. The protective layer 5 can be obtained by curing by applying at a temperature of, for example, 100 ° C. or more and 170 or less if necessary.

  The coating liquid for forming a film is used for, for example, an antistatic film on a fluorescent coloring paint, a glass surface, a plastic surface, etc., in addition to the use as a photoreceptor. When this coating liquid for forming a film is used, a film having excellent adhesion to the lower layer is formed, and performance deterioration due to repeated use over a long period is suppressed.

  Here, the electrophotographic photoreceptor has been described as an example of the function separation type, but the content of the charge generation material in the single-layer type photosensitive layer 6 (charge generation / charge transport layer) is 10% by mass or more and 85% by mass. % Or less, desirably 20 mass% or more and 50 mass% or less. In addition, the content of the charge transport material is desirably 5% by mass or more and 50% by mass or less. The method for forming the single-layer type photosensitive layer 6 (charge generation / charge transport layer) is the same as the method for forming the charge generation layer 2 and the charge transport layer 3. The film thickness of the single-layer type photosensitive layer (charge generation / charge transport layer) 6 is preferably about 5 μm to 50 μm, and more preferably 10 μm to 40 μm.

  In the embodiment, a form in which a crosslinked product of a guanamine compound (a compound represented by the general formula (A)) and a specific charge transporting material (a compound represented by the general formula (I)) is used for the protective layer 5. However, in the case of a layer configuration without the protective layer 5, for example, it may be used for a charge transport layer located in the outermost surface layer.

(Image forming device / process cartridge)
FIG. 4 is a schematic configuration diagram illustrating the image forming apparatus according to the embodiment. The image forming apparatus 100 is as shown in FIG. A process cartridge 300 including the electrophotographic photosensitive member 7, an exposure device 9, a transfer device 40, and an intermediate transfer member 50 are provided. In the image forming apparatus 100, the exposure device 9 is disposed at a position where the electrophotographic photosensitive member 7 can be exposed from the opening of the process cartridge 300, and the transfer device 40 is interposed between the electrophotographic photosensitive member via the intermediate transfer member 50. 7, and a part of the intermediate transfer member 50 is disposed in contact with the electrophotographic photosensitive member 7.

  The process cartridge 300 in FIG. 4 integrally supports the electrophotographic photoreceptor 7, the charging device 8, the developing device 11, and the cleaning device 13 in a housing. The cleaning device 13 has a cleaning blade (cleaning member), and the cleaning blade 131 is disposed so as to contact the surface of the electrophotographic photosensitive member 7.

  Further, an example is shown in which a fibrous member 132 (roll shape) for supplying the lubricant 14 to the surface of the photoreceptor 7 and a fibrous member 133 (flat brush shape) for assisting cleaning are used. It may be used accordingly.

  As the charging device 8, for example, a contact type charger using a conductive or semiconductive charging roller, a charging brush, a charging film, a charging rubber blade, a charging tube or the like is used. Further, a non-contact type roller charger, a known charger such as a scorotron charger using a corona discharge or a corotron charger may be used.

  Although not shown, a photosensitive member heating member for increasing the temperature of the electrophotographic photosensitive member 7 and reducing the relative temperature is provided around the electrophotographic photosensitive member 7 for the purpose of improving the stability of the image. Also good.

  Examples of the exposure apparatus 9 include optical system devices that expose the surface of the photoconductor 7 with light such as semiconductor laser light, LED light, and liquid crystal shutter light in a desired image-like manner. The wavelength of the light source is in the spectral sensitivity region of the photoreceptor. As the wavelength of the semiconductor laser, near infrared having an oscillation wavelength near 780 nm is the mainstream. However, the present invention is not limited to this wavelength, and an oscillation wavelength laser in the 600 nm range or a laser having an oscillation wavelength in the vicinity of 400 nm to 450 nm as a blue laser may be used. For color image formation, a surface-emitting laser light source capable of multi-beam output is also effective.

  As the developing device 11, for example, a general developing device that performs development by bringing a magnetic or non-magnetic one-component developer or a two-component developer into contact or non-contact may be used. The developing device is not particularly limited as long as it has the functions described above, and is selected according to the purpose. For example, a known developing device having a function of attaching the one-component developer or the two-component developer to the photoreceptor 7 using a brush, a roller, or the like can be used. Among these, those using a developing roller holding the developer on the surface are preferable.

Hereinafter, the toner used in the developing device 11 will be described.
The toner used in the image forming apparatus of the present embodiment has an average shape factor ((ML ² / A) × (π / 4) × 100, where ML is a value from the viewpoint of obtaining high developability and transferability and high image quality. The maximum length of the particle is represented, and A represents the projected area of the particle) is preferably from 100 to 150, more preferably from 105 to 145, and even more preferably from 110 to 140. Further, the toner preferably has a volume average particle diameter of 3 μm or more and 12 μm or less, more preferably 3.5 μm or more and 10 μm or less, and further preferably 4 μm or more and 9 μm or less. By using a toner that satisfies this average shape factor and volume average particle diameter, the developability and transferability are improved, and a so-called high-quality image called photographic image quality is obtained.

  The toner is not particularly limited by the production method as long as it satisfies the above average shape factor and volume average particle diameter. For example, the toner may include a binder resin, a colorant, a release agent, and the like. A kneading and pulverizing method in which a charge control agent is added, kneading, pulverizing, and classifying; a method in which the shape of particles obtained by the kneading and pulverizing method is changed by mechanical impact force or thermal energy; Emulsion polymerization of the body, and the resulting dispersion is mixed with a dispersion of a colorant, a release agent and, if necessary, a charge control agent, and then agglomerated and heat-fused to obtain toner particles. Suspension polymerization method in which a polymerizable monomer for obtaining a binder resin, a colorant, a release agent, and a charge control agent, if necessary, are suspended in an aqueous solvent and polymerized; A water-based solution of the resin, a colorant, a release agent, and a solution such as a charge control agent as necessary. Toner is used which is suspended in and produced by a dissolution suspension method in which granulated.

  Further, a known method such as a production method in which the toner obtained by the above method is used as a core, and agglomerated particles are further adhered and heat-fused to give a core-shell structure is used. The toner production method is preferably a suspension polymerization method, an emulsion polymerization aggregation method, or a dissolution suspension method in which an aqueous solvent is used from the viewpoint of shape control and particle size distribution control, and an emulsion polymerization aggregation method is particularly desirable.

  The toner base particles are composed of a binder resin, a colorant, and a release agent, and include silica and a charge control agent as necessary.

  Binder resins used for toner base particles include styrenes such as styrene and chlorostyrene, monoolefins such as ethylene, propylene, butylene and isoprene, vinyl acetate, vinyl propionate, vinyl benzoate, vinyl butyrate, etc. Α-methylene aliphatics such as vinyl esters, methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, dodecyl methacrylate Homopolymers and copolymers of monocarboxylic acid esters, vinyl ethers such as vinyl methyl ether, vinyl ethyl ether and vinyl butyl ether, vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone and vinyl isopropenyl ketone Polyester resins by copolymerization of dicarboxylic acids and diols.

  Particularly representative binder resins include polystyrene, styrene-alkyl acrylate copolymer, styrene-alkyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, and styrene-maleic anhydride copolymer. A polymer, polyethylene, a polypropylene, a polyester resin etc. are mentioned. Further, polyurethane, epoxy resin, silicone resin, polyamide, modified rosin, paraffin wax and the like can be mentioned.

  In addition, as colorants, magnetic powders such as magnetite and ferrite, carbon black, aniline blue, caryl blue, chrome yellow, ultramarine blue, Dupont oil red, quinoline yellow, methylene blue chloride, phthalocyanine blue, malachite green oxalate, Lamp Black, Rose Bengal, C.I. I. Pigment red 48: 1, C.I. I. Pigment red 122, C.I. I. Pigment red 57: 1, C.I. I. Pigment yellow 97, C.I. I. Pigment yellow 17, C.I. I. Pigment blue 15: 1, C.I. I. Pigment Blue 15: 3 is exemplified as a representative example.

  Typical examples of the release agent include low molecular weight polyethylene, low molecular weight polypropylene, Fischer tropical wax, montan wax, carnauba wax, rice wax, and candelilla wax.

  As the charge control agent, known ones are used, and azo metal complex compounds, metal complex compounds of salicylic acid, and resin type charge control agents containing polar groups are used. When toner is produced by a wet process, it is desirable to use a material that is difficult to dissolve in water in terms of controlling ionic strength and reducing wastewater contamination. The toner may be either a magnetic toner containing a magnetic material or a non-magnetic toner containing no magnetic material.

  As the toner used in the developing device 11, the toner base particles and the external additive are mixed with a Henschel mixer or a V blender.

Manufactured by mixing. In addition, when the toner base particles are produced by a wet method, external addition can also be performed by a wet method.

  Lubricating particles may be added to the toner used in the developing device 11. Lubricating particles include solid lubricants such as graphite, molybdenum disulfide, talc, fatty acids and fatty acid metal salts, low molecular weight polyolefins such as polypropylene, polyethylene and polybutene, silicones having a softening point upon heating, oleic amides , Erucic acid amide, ricinoleic acid amide, stearic acid amide and other aliphatic amides, carnauba wax, rice wax, candelilla wax, tree wax, jojoba oil and other plant wax, beeswax animal wax, montan wax, Minerals such as ozokerite, ceresin, paraffin wax, microcrystalline wax, Fischer-Tropsch wax, petroleum-based wax, and modified products thereof are used. These are used individually by 1 type or in combination of 2 or more types. However, the average particle size is preferably in the range of 0.1 μm or more and 10 μm or less, and those having the above chemical structure may be pulverized to make the particle sizes uniform. The amount added to the toner is desirably in the range of 0.05% by mass to 2.0% by mass, and more desirably in the range of 0.1% by mass to 1.5% by mass.

  To the toner used in the developing device 11, inorganic particles, organic particles, composite particles obtained by attaching inorganic particles to the organic particles, and the like may be added for the purpose of removing deposits and deteriorated materials on the surface of the electrophotographic photosensitive member. .

  Inorganic particles include silica, alumina, titania, zirconia, barium titanate, aluminum titanate, strontium titanate, magnesium titanate, zinc oxide, chromium oxide, cerium oxide, antimony oxide, tungsten oxide, tin oxide, tellurium oxide, Various inorganic oxides such as manganese oxide, boron oxide, silicon carbide, boron carbide, titanium carbide, silicon nitride, titanium nitride, and boron nitride, nitrides, borides, and the like are preferably used.

  In addition, the inorganic particles may be mixed with titanium coupling agents such as tetrabutyl titanate, tetraoctyl titanate, isopropyl triisostearoyl titanate, isopropyl tridecylbenzene sulfonyl titanate, bis (dioctyl pyrophosphate) oxyacetate titanate, γ- (2- Aminoethyl) aminopropyltrimethoxysilane, γ- (2-aminoethyl) aminopropylmethyldimethoxysilane, γ-methacryloxypropyltrimethoxysilane, N-β- (N-vinylbenzylaminoethyl) γ-aminopropyltrimethoxy Silane hydrochloride, hexamethyldisilazane, methyltrimethoxysilane, butyltrimethoxysilane, isobutyltrimethoxysilane, hexyltrimethoxysilane, octyltrimethoxysilane The treatment may be performed with a silane coupling agent such as run, decyltrimethoxysilane, dodecyltrimethoxysilane, phenyltrimethoxysilane, o-methylphenyltrimethoxysilane, and p-methylphenyltrimethoxysilane. In addition, those hydrophobized with higher fatty acid metal salts such as silicone oil, aluminum stearate, zinc stearate, calcium stearate and the like are also desirably used.

  Examples of the organic particles include styrene resin particles, styrene acrylic resin particles, polyester resin particles, and urethane resin particles.

  The particle diameter is preferably 5 nm to 1000 nm, more preferably 5 nm to 800 nm, and even more preferably 5 nm to 700 nm in terms of number average particle diameter. If the average particle size is less than the lower limit, the polishing ability tends to be lacking. On the other hand, if the average particle size exceeds the upper limit, the surface of the electrophotographic photoreceptor tends to be damaged. Moreover, it is desirable that the sum of the addition amounts of the above-described particles and the lubricating particles is 0.6% by mass or more.

  Other inorganic oxides added to the toner are small-diameter inorganic oxides with a primary particle size of 40 nm or less for powder flowability, charge control, etc. It is desirable to add a larger diameter inorganic oxide. Known inorganic oxide particles are used, but it is desirable to use silica and titanium oxide in combination for precise charge control.

Further, the surface treatment of the small-diameter inorganic particles increases the dispersibility and increases the effect of increasing the powder fluidity. Furthermore, it is desirable to add carbonates such as calcium carbonate and magnesium carbonate and inorganic minerals such as hydrotalcite in order to remove the discharge purified product.

  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 coated with a resin are used. The mixing ratio with the carrier is set.

  As the transfer device 40, for example, a contact transfer charger using a belt, a roller, a film, a rubber blade, etc., or a known transfer charger such as a scorotron transfer charger using a corona discharge or a corotron transfer charger. Can be mentioned.

  As the intermediate transfer member 50, a belt-like member (intermediate transfer belt) made of polyimide, polyamideimide, polycarbonate, polyarylate, polyester, rubber or the like having semiconductivity is used. Further, as the form of the intermediate transfer member 50, a drum-like one is used in addition to the belt-like shape.

  In addition to the above-described devices, the image forming apparatus 100 may include, for example, a light neutralizing device that performs light neutralization on the photoconductor 7.

  FIG. 5 is a schematic cross-sectional view showing an image forming apparatus according to another embodiment. As shown in FIG. 5, the image forming apparatus 120 is a tandem-type full-color image forming apparatus equipped with four process cartridges 300. In the image forming apparatus 120, four process cartridges 300 are arranged in parallel on the intermediate transfer member 50, and one electrophotographic photosensitive member is used for one color. The image forming apparatus 120 has the same configuration as that of the image forming apparatus 100 except that it is a tandem system.

  When the electrophotographic photosensitive member of the present invention is used in a tandem type image forming apparatus, the electric characteristics of the four photosensitive members are stabilized, so that an image quality with excellent color balance can be obtained over a longer period.

Further, in the image forming apparatus (process cartridge) according to the present embodiment, the developing device (developing means) is a developer holder that moves (rotates) in the opposite direction to the moving direction (rotating direction) of the electrophotographic photosensitive member. It is desirable to have a developing roller that is Here, the developing roller has a cylindrical developing sleeve that holds developer on the surface, and the developing device has a configuration that includes a regulating member that regulates the amount of developer supplied to the developing sleeve. Can be mentioned. By moving (rotating) the developing roller of the developing device in a direction opposite to the rotation direction of the electrophotographic photosensitive member, the surface of the electrophotographic photosensitive member is rubbed with toner remaining between the developing roller and the electrophotographic photosensitive member. The And the deposits enhanced by this rubbing and a crosslinked product of a guanamine compound and a specific charge transporting material (in particular, a material capable of obtaining a cured film having a high crosslinking density by increasing the number of reactive functional groups as described above) The removal property improves the scraping property of the discharge products (especially low resistance substances caused by ozone and NOx) adhering to the surface of the electrophotographic photosensitive member, and the deposition of such discharge products is suppressed for a very long time. It is thought. As a result, the occurrence of image quality defects peculiar to a high wear resistance photoconductor such as resolution reduction, streaks, and image blurring is suppressed, and it is assumed that higher image quality and longer life have been achieved at a higher level. Moreover, it is considered that excellent slipperiness of the electrophotographic photosensitive member surface is maintained over a long period of time by suppressing the accumulation of discharge products. As a result, the cleaning blade can be prevented from turning over or generating abnormal noise, and a high level of cleaning performance can be maintained for a long time.
In the image forming apparatus of the present embodiment, the distance between the developing sleeve and the photosensitive member is preferably 200 μm or more and 600 μm or less, and preferably 300 μm or more and 500 μm, from the viewpoint of suppressing the accumulation of discharge products over a longer period. More preferably, it is as follows. From the same viewpoint, the distance between the developing sleeve and the regulating blade that is a regulating member that regulates the developer amount is preferably 300 μm or more and 1000 μm or less, and more preferably 400 μm or more and 750 μm or less.
Further, from the viewpoint of suppressing the accumulation of discharge products over a longer period, the absolute value of the moving speed of the developing roll surface is 1.5 times or more the absolute value (process speed) of the moving speed of the photoreceptor surface. It is preferably 5 times or less, more preferably 1.7 times or more and 2.0 times or less.

  Further, in the image forming apparatus (process cartridge) according to the present embodiment, the developing device (developing unit) includes a developer holding body having a magnetic material, and is a two-component developer containing a magnetic carrier and toner. It is desirable to develop an image. In this configuration, a clearer image quality can be obtained with a color image, and higher image quality and longer life can be achieved compared to the case of a one-component developer, particularly a non-magnetic one-component developer.

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

<Guanamine resin (G-1)>
500 parts by mass of Superbecamine (R) L-148-55 (Butylated benzoguanamine resin: manufactured by Dainippon Ink Co., Ltd.) containing the structure of A-15 was dissolved in 500 parts by mass of xylene, and each using 300 ml of distilled water. Washed 5 times with water. The conductivity of the final wash water was 6 μS / cm. The solvent was distilled off from the solution under reduced pressure to obtain 250 parts by weight of a candy-like resin. This is designated as guanamine resin G-1.

    Here, the electrical conductivity was measured at room temperature (about 20 °) using washing water with a direct conductivity meter (Conductivity Meter DS-12: manufactured by HORIBA, Ltd.).

<Guanamine resin (G-2)>
500 parts by mass of Superbecamine (R) 13-535 (methylated benzoguanamine resin: manufactured by Dainippon Ink Co., Ltd.) containing the structure of A-14 is dissolved in 500 parts by mass of xylene, and each time 5 times using 300 ml of distilled water. Washed with water. The conductivity of the final wash water was 7 μS / cm. The solvent was distilled off from the solution under reduced pressure to obtain 270 parts by weight of a candy-like resin. This is designated as guanamine resin G-2.

<Guanamine resin (G-3)>
500 parts by mass of Superbecamine (R) L-148-55 (Butylated benzoguanamine resin: Dainippon Ink Co., Ltd.) containing the structure of A-15 was dissolved in 500 parts by mass of xylene, and cation exchange resin: Amberlite 15 (manufactured by Rohm and Haas), 20 parts by mass, anion exchange resin: Amberlite IRA-400 (manufactured by Rohm and Haas), 20 parts by mass, and after stirring for 20 minutes, ion exchange resin Was filtered. 10 parts by mass of distilled water was added to 10 parts by mass of this solution, stirred, allowed to stand, and the conductivity of the separated aqueous phase was measured to find 3 μS / cm. The solvent of the resin solution was distilled off under reduced pressure to obtain 250 parts by mass of a candy-like resin. This is designated as guanamine resin G-3.

<Guanamine resin (G-4)>
Superbecamine (R) L-148-55 containing the structure of A-15 is referred to as guanamine resin G-4.

<Guanamine resin (G-5)>
Superbecamine (R) 13-535 containing the structure of A-14 is referred to as guanamine resin G-5.

<Guanamine resin (G-6)>
Nicarac BL-60 (manufactured by Nippon Carbide) containing the structure of A-17 as it is is referred to as guanamine resin G-6. This resin contains about 37% by mass of a xylene-based solvent.

<Catalyst-1>
Paratoluenesulfonic acid is used as catalyst-1.

<Catalyst-2>
NACURE2501 (manufactured by King Industry) is referred to as catalyst-2.

<Catalyst-3>
NACURE 5225 (manufactured by King Industry) is referred to as catalyst-3.

<Catalyst-4>
NACURE4167 (manufactured by King Industry) is referred to as catalyst-4.

<Example 1>
An electrophotographic photoreceptor was prepared as follows.

(Preparation of undercoat layer)
Zinc oxide: (average particle size 70 nm: manufactured by Teica Co., Ltd .: specific surface area value 15 m ² / g) 100 parts by mass is stirred and mixed with 500 parts by mass of tetrahydrofuran, and silane coupling agent (KBM503: manufactured by Shin-Etsu Chemical Co., Ltd.) 1.3 masses. Part was added and stirred for 2 hours. Thereafter, toluene was distilled off under reduced pressure and baked at 120 ° C. for 3 hours to obtain a silane coupling agent surface-treated zinc oxide.
110 parts by mass of the surface-treated zinc oxide was stirred and mixed with 500 parts by mass of tetrahydrofuran, a solution prepared by dissolving 0.6 parts by mass of alizarin in 50 parts by mass of tetrahydrofuran was added, and the mixture was stirred at 50 ° C. for 5 hours. did. Then, the zinc oxide to which alizarin was imparted by filtration under reduced pressure was filtered off, and further dried at 60 ° C. under reduced pressure to obtain alizarin imparted zinc oxide.

  60 parts by mass of this alizarin-provided zinc oxide and a curing agent (blocked isocyanate Sumijoule 3175, manufactured by Sumitomo Bayern Urethane Co., Ltd.): 13.5 parts by mass and butyral resin (ESREC BM-1, manufactured by Sekisui Chemical Co., Ltd.) 15 parts by mass of methyl ethyl ketone 38 parts by mass of the solution dissolved in 85 parts by mass and 25 parts by mass of methyl ethyl ketone were mixed, and dispersion was performed for 2 hours with a sand mill using 1 mmφ glass beads.

  Dioctyltin dilaurate: 0.005 parts by mass and silicone resin particles (Tospearl 145, manufactured by GE Toshiba Silicone): 40 parts by mass were added as catalysts to the resulting dispersion to obtain an undercoat layer coating solution. This coating solution was applied onto an aluminum substrate having a diameter of 30 mm, a length of 340 mm, and a thickness of 1 mm by a dip coating method, followed by drying and curing at 170 ° C. for 40 minutes to obtain an undercoat layer having a thickness of 18 μm.

(Preparation of charge generation layer)
Bragg angles (2θ ± 0.2 °) of X-ray diffraction spectrum using Cukα characteristic X-ray as a charge generating material are at least 7.3 °, 16.0 °, 24.9 °, 28.0 ° A mixture consisting of 15 parts by mass of hydroxygallium phthalocyanine having a diffraction peak, 10 parts by mass of vinyl chloride / vinyl acetate copolymer resin (VMCH, manufactured by Nihon Unicar) as a binder resin, and 200 parts by mass of n-butyl acetate, The glass beads having a diameter of 1 mmφ were dispersed for 4 hours by a sand mill. To the obtained dispersion, 175 parts by mass of n-butyl acetate and 180 parts by mass of methyl ethyl ketone were added and stirred to obtain a coating solution for a charge generation layer. This charge generation layer coating solution was dip coated on the undercoat layer and dried at room temperature (25 ° C.) to form a charge generation layer having a thickness of 0.2 μm.

(Preparation of charge transport layer)
N, N′-diphenyl-N, N′-bis (3-methylphenyl)-[1,1 ′] biphenyl-4,4′-diamine 45 parts by mass and bisphenol Z polycarbonate resin (viscosity average molecular weight: 40,000) 55 parts by mass was added to 800 parts by mass of chlorobenzene and dissolved to obtain a charge transport layer coating solution. This coating solution was applied onto the charge generation layer and dried at 130 ° C. for 45 minutes to form a charge transport layer having a thickness of 15 μm.

(Preparation of protective layer)
Guanamine resin G-1: 3 parts by mass, 3 parts by mass of the compound represented by (I-2), colloidal silica (trade name: PL-1, manufactured by Fuso Chemical Industry Co., Ltd.) 0.3 parts by mass, polyvinylphenol resin (weight) (Average molecular weight of about 8000, made by Aldrich) 0.2 parts by mass, 1-methoxy-2-propanol 8 parts by mass, and 3,5-di-t-butyl-4-hydroxytoluene (BHT) 0.2 parts by mass, p -Toluenesulfonic acid 0.01 mass part was added and the coating liquid for protective layers was prepared. This coating solution is applied on the charge transport layer by a dip coating method, air-dried at room temperature (25 ° C.) for 30 minutes, and then cured by heat treatment at 150 ° C. for 1 hour to form a protective layer having a thickness of about 7 μm. Thus, a photoreceptor of Example 1 was produced.

  The photoreceptor after the charge transport layer was formed was kept immersed in the protective layer coating solution for 1 hour, but N, N′-diphenyl-N, N′-bis (3-methylphenyl)-[1 , 1 ′] biphenyl-4,4′-diamine was not eluted into the coating solution for the protective layer.

[Image quality evaluation]
The electrophotographic photosensitive member produced as described above is attached to Fuji Xerox Co., Ltd., DocuCentre Color 400CP, and at low temperature and low humidity (8 ° C., 20% RH) and high temperature and high humidity (28 ° C., 85% RH), the following Evaluation was performed continuously. Note that the developing device is set so that the moving direction of the developer roll (developer holding member) and the electrophotographic photosensitive member in the rubbing portion is the same (hereinafter may be referred to as “with method”). The one installed was used.
That is, the image quality immediately after printing the 5000th sheet after performing the image formation test of 5000 sheets of 10% halftone images continuously in an environment of low temperature and low humidity (8 ° C., 20% RH), and the 5000 sheet image formation test. Then, the following ghost, fog, streak and image flow were evaluated for the initial image quality after being left for 24 hours in a low temperature and low humidity (8 ° C., 20% RH) environment.
The results are shown in Table 2.

Following the image quality evaluation in this low-temperature and low-humidity environment, the 5000th image formation test was performed on 5000 sheets of 10% halftone images continuously in a high-temperature and high-humidity environment (28 ° C., 85% RH). The following ghost, fog, streak, and image for the image quality immediately after printing and the initial image quality after leaving the image in the high-temperature and high-humidity (28 ° C., 85% RH) environment for 24 hours after performing the 5000 sheet image formation test. The flow was evaluated.
The results are shown in Table 3.
In the image forming test, P paper (A3 size) manufactured by Fuji Xerox Office Supply was used.

(Ghost evaluation)
For the ghost, a chart of a pattern having G and a black area shown in FIG. 6A was printed, and the appearance of the letter G in the black area was visually evaluated.
A: Good or slight as shown in FIG.
B: Slightly conspicuous as shown in FIG. 6 (B) C: It is clearly confirmed as shown in FIG. 6 (C).

(Fog evaluation)
The fog evaluation was performed by visually observing and judging the degree of toner adhesion on the white background using the same sample as the ghost evaluation described above.
A: Good.
B: There is a slight fog (no problem in image quality).
C: There is fogging that causes a problem in image quality.

(Streak evaluation)
The streak evaluation was judged visually using the same sample as the ghost evaluation described above.
A: Good.
B: Streaks are partially generated.
C: Streaks that cause image quality problems.

(Image flow evaluation)
For the image flow, the same sample as the above-described ghost evaluation was used, and in the image formation test at the low temperature and low humidity and the high temperature and high humidity, the density reduction of the black region portion was visually determined.
A: Good.
B: No problem during continuous print test, but occurs after standing for 24 hours.
C: Occurs during continuous print test.

[Evaluation of protective layer adhesion]
The protective layer has an adhesive property of 5 × 5 (25 in total) cuts with a cutter knife on the photoconductor after the image formation test, and a 3M mending tape is applied to the adhesive surface. The remaining number when peeled in the direction of 90 degrees was evaluated. The results are shown in Table 2.
A: 21 or more remained.
B: 11 to 20 remaining.
C: 10 or less remained.

[Torque measurement]
The electrophotographic photosensitive member produced as described above was mounted on a DocuCentre Color 400CP manufactured by Fuji Xerox Co., Ltd., and an entire image having a color image density of 20% was printed. After that, the drum cartridge is taken out, and a manual torque gauge (BTG90CN-S: Tohnichi Manufacturing Co., Ltd.) is attached to the drum cartridge photoconductor. The torque gauge is rotated from the stationary state to the rotating state, and the maximum torque during that time is measured. The test was carried out three times in a low-temperature and low-humidity (8 ° C., 20% RH) environment, and the average value was defined as the photoreceptor torque. The results are shown in Table 2.

<Examples 2 to 13>
According to Table 1, except that the guanamine resin (compound represented by the general formula (A)), the charge transport material (compound represented by the general formula (I)), the additive, the catalyst, and the use amount thereof were changed. Photoconductors 2 to 13 were prepared in the same manner as in Example 1, and the same evaluation was performed. The results are shown in Tables 2 and 3.

<Example 14>
A photoconductor 14 having a protective layer was prepared in the same manner as in Example 1 except that the charge transport layer was prepared as follows, and the same evaluation was performed. The results are shown in Tables 2 and 3.

(Preparation of charge transport layer)
45 parts by mass of the following compound (α) and 55 parts by mass of bisphenol Z polycarbonate resin (viscosity average molecular weight: 40,000) were added to 800 parts by mass of chlorobenzene and dissolved to obtain a coating solution for a charge transport layer. This coating solution was applied onto the charge generation layer and dried at 130 ° C. for 45 minutes to form a charge transport layer having a thickness of 17 μm.

<Example 15>
A photoconductor 15 having a protective layer was produced in the same manner as in Example 1 except that the charge transport layer was produced as follows, and the same evaluation was performed. The results are shown in Tables 2 and 3.

(Preparation of charge transport layer)
50 parts by mass of the following compound (β) and 50 parts by mass of bisphenol Z polycarbonate resin (viscosity average molecular weight: 50,000) were added to 800 parts by mass of chlorobenzene and dissolved to obtain a coating solution for a charge transport layer. This coating solution was applied onto the charge generation layer and dried at 130 ° C. for 45 minutes to form a charge transport layer having a thickness of 15 μm.

<Example 16>
A photoconductor 15 having a protective layer was produced in the same manner as in Example 1 except that the charge transport layer was produced as follows, and the same evaluation was performed. The results are shown in Tables 2 and 3.

(Preparation of charge transport layer)
50 parts by mass of the following compound (γ) and 50 parts by mass of bisphenol Z polycarbonate resin (viscosity average molecular weight: 80,000) were added to 800 parts by mass of chlorobenzene and dissolved to obtain a coating solution for a charge transport layer. This coating solution was applied onto the charge generation layer and dried at 130 ° C. for 45 minutes to form a charge transport layer having a thickness of 15 μm.

<Examples 17 to 23>
According to Table 1, except that the guanamine resin (compound represented by the general formula (A)), the charge transport material (compound represented by the general formula (I)), the additive, the catalyst, and the use amount thereof were changed. Photoconductors 17 to 23 were prepared in the same manner as in Example 1, and the same evaluation was performed. The results are shown in Tables 2 and 3.

<Comparative Examples 1 to 4>
Comparative photoreceptors 1 to 4 were prepared in the same manner as in Examples 1, 14, 15, and 16 except that the protective layer was not provided, and evaluated in the same manner as in Example 1. The results are shown in Tables 2 and 3.

<Comparative Examples 5 to 7>
60 parts by mass of powder composed of conductive particles (S-1, manufactured by Mitsubishi Materials Corporation) having a coating film of tin oxide doped with antimony, and titanium oxide (titone R-1T, manufactured by Sakai Chemical Co., Ltd.) 30 parts by mass, 60 parts by mass of resol type phenolic resin (Phenolite J-325, manufactured by Dainippon Ink & Chemicals, Inc., solid content 70% by mass), 50 parts by mass of 2-methoxy-1-propanol, and methanol A solution consisting of 50 parts by mass was dispersed with a ball mill for about 20 hours. This dispersion was applied onto the charge transport layers of Examples 1, 15, and 16 to form a protective layer having a thickness of 5 μm, and photoconductors of comparative photoconductors 5 to 8 were produced. Evaluation was made in the same manner as in Example 1. did. The results are shown in Tables 2 and 3.

<Comparative Example 8>
6 parts by mass of the following compound (Δ), 7 parts by mass of guanamine resin G-6, 0.5 parts by mass of butyral resin, 0.5 parts by mass of bisglycidyl bisphenol A, and 0.5 parts by mass of biphenyltetracarboxylic acid 0.03 part by mass of methylphenylpolysiloxane and 0.2 part by mass of Sanol LS2626 were dissolved in 7 parts by mass of isopropanol. This coating solution was applied onto the charge transport layer by the dip coating method in the same manner as in Example 1 and air-dried at room temperature for 30 minutes, and then cured by heat treatment at 150 ° C. for 1 hour to form a protective layer having a thickness of about 7 μm. A comparative photoconductor 8 was produced and evaluated in the same manner as in Example 1. The results are shown in Tables 2 and 3.
The obtained comparative photoconductor was subjected to 10,000 image forming tests in an environment of high temperature and high humidity (28 ° C., 85% RH), and the surface of the photoconductor was observed. The peeled part was observed.
Further, after the photoreceptor having the charge transport layer formed thereon was kept immersed in the protective layer coating solution for 1 hour, the protective layer coating solution was irradiated with ultraviolet rays (356 nm), and N, N′-diphenyl-N, Since N′-bis (3-methylphenyl)-[1,1 ′] biphenyl-4,4′-diamine was eluted into the protective layer coating solution, blue fluorescence was observed.

<Examples 24 to 27>
The electrophotographic photosensitive member is the electrophotographic photosensitive member produced in Examples 1, 9, 13, and 23. The evaluation device is based on a Docu Center Color 400CP machine manufactured by Fuji Xerox Co., Ltd. A developer provided with a developing device set so that the moving direction of the developer roll (developer holder) and the electrophotographic photosensitive member is opposite (hereinafter sometimes referred to as “against method”) was used. The developing roll peripheral speed is set to 182 mm / sec (1.75 times the process speed), and the developing roll and the regulation are set so that the developer amount per unit area on the developing roll is the same in the width method and the against method. The distance from the blade was adjusted. The same test as in Example 1 was performed with this combination, and the results obtained are shown in Tables 2 and 3.

  In Table 1, S-1 represents a trade name S-1 which is a conductive particle having an antimony-doped tin oxide coating film manufactured by Mitsubishi Materials Corporation, and PTFE is a PTFE particle manufactured by Daikin Industries, Ltd. Trade name: Lubron L-2, butyral resin (BM-1) is a butyral resin made by Sekisui Chemical Co., Ltd. Trade name: ESREC BM-1, Sanol LS770, made by Sankyo Lifetech, antioxidant The trade name SANOL LS770 which is an agent is represented. The phenol resin represents PL-4852 manufactured by Gunei Chemical Co., and the melamine resin represents MW-30 manufactured by Sanwa Chemical Co., Ltd.

1 is a schematic partial cross-sectional view showing an electrophotographic photosensitive member according to an embodiment. 1 is a schematic partial cross-sectional view showing an electrophotographic photosensitive member according to an embodiment. 1 is a schematic partial cross-sectional view showing an electrophotographic photosensitive member according to an embodiment. 1 is a schematic configuration diagram illustrating an image forming apparatus according to an embodiment. It is a schematic block diagram which shows the image forming apparatus which concerns on other embodiment. (A) thru | or (C) are explanatory drawings which respectively show the reference | standard of ghost evaluation.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Undercoat layer 2 Charge generation layer 3 Charge transport layer 4 Conductive substrate 5 Protective layer 6 Single layer type photosensitive layer 7 Electrophotographic photoreceptor 8 Charging device 9 Exposure device 11 Development device 13 Cleaning device 14 Lubricant 40 Transfer device 50 Intermediate Transfer body 100 Image forming apparatus 120 Image forming apparatus 132 Fibrous member (roll shape)
133 Fibrous member (flat brush shape)

Claims (13)

A conductive substrate;
A photosensitive layer provided on the surface of the conductive substrate;
Have
The outermost surface layer of the photosensitive layer is a guanamine compound and at least one kind of charge transporting material having at least one substituent selected from —OH, —OCH ₃ , —NH ₂ , —SH, and —COOH. An electrophotographic photosensitive member comprising a cross-linked product using 2. The electrophotographic photoreceptor according to claim 1, wherein the guanamine compound is at least one of a compound represented by the following general formula (A) and a multimer thereof.

(In the general formula (A), R ₁ is a linear or branched alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted phenyl group having 6 to 10 carbon atoms, or 4 carbon atoms. The substituted or unsubstituted alicyclic hydrocarbon group is 10 or more and R _{2 to} R ₅ each independently represents hydrogen, —CH ₂ —OH, or —CH ₂ —O—R ₆ , R _6. Represents hydrogen or a linear or branched alkyl group having 1 to 10 carbon atoms.) In the general formula (A), R ₁ represents a substituted or unsubstituted phenyl group having 6 to 10 carbon atoms, and R _{2 to} R ₅ represent —CH ₂ —O—R _6. 2. The electrophotographic photosensitive member according to 2. 4. The electrophotographic photosensitive member according to claim 2, wherein, in the general formula (A), R ₆ is selected from a methyl group and an n-butyl group. The charge transporting material is a charge transporting material having at least three substituents selected from —OH, —OCH ₃ , —NH ₂ , —SH, and —COOH. 5. The electrophotographic photosensitive member according to any one of 4 above. The electrophotographic photosensitive member according to claim 1, wherein the charge transporting material is a compound represented by the following general formula (I).
_{F - ((- R 7 -X} ) n1 R 8 -Y) n2 (I)
(In general formula (I), F is an organic group derived from a compound having a hole transporting ability, and R ₇ and R ₈ are each independently a linear or branched alkylene group having 1 to 5 carbon atoms. , N1 represents 0 or 1, n2 represents an integer of 1 to 4, X represents an oxygen, NH, or sulfur atom, Y represents —OH, —OCH ₃ , —NH ₂ , —SH, or — COOH is shown.)   The electrophotographic photosensitive member according to claim 6, wherein n2 represents 3 or 4 in the compound represented by the general formula (I). An electrophotographic photoreceptor according to any one of claims 1 to 7,
Charging means for charging the electrophotographic photosensitive member, developing means for developing the electrostatic latent image formed on the electrophotographic photosensitive member with toner, and toner removal for removing toner remaining on the surface of the electrophotographic photosensitive member A process cartridge comprising: at least one selected from the group consisting of means.   9. The process cartridge according to claim 8, wherein the developing unit includes a developer holding member that moves in a direction opposite to a moving direction of the electrophotographic photosensitive member. An electrophotographic photoreceptor according to any one of claims 1 to 7,
Charging means for charging the electrophotographic photoreceptor;
Electrostatic latent image means for forming an electrostatic latent image on the charged electrophotographic photosensitive member;
Developing means for developing the electrostatic latent image formed on the electrophotographic photosensitive member with toner;
Transfer means for transferring the toner image to a transfer object;
An image forming apparatus comprising:   The image forming apparatus according to claim 10, wherein the developing unit includes a developer holder that moves in a direction opposite to a moving direction of the electrophotographic photosensitive member. Coating solution for forming a film, comprising at least a guanamine compound and at least one charge transporting material having at least one substituent selected from —OH, —OCH ₃ , —NH ₂ , —SH, and —COOH. . A conductive substrate;
A photosensitive layer provided on the surface of the conductive substrate;
Have
The outermost surface layer of the photosensitive layer is a guanamine compound and at least one kind of charge transporting material having at least one substituent selected from —OH, —OCH ₃ , —NH ₂ , —SH, and —COOH. An electrophotographic photosensitive member comprising: a film formed by coating a coating solution for forming a film containing