JP2015180923A - Electrophotographic photoreceptor, manufacturing method of the same, process cartridge, and electrophotographic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor that has suppressed a fluctuation in the potential of a bright part when images are repeatedly formed under a high-temperature and high-humidity environment, a process cartridge and an electrophotographic device including the electrophotographic photoreceptor, and a manufacturing method of the electrophotographic photoreceptor.SOLUTION: An electrophotographic photoreceptor includes an undercoat layer that contains composite particles; the composite particles each include a core material particle and tin oxide coating the core material particle; the tin oxide of the composite particles has a peak at 33.90° of the Bragg angle (2θ±0.20°) in CuKα characteristic X-ray diffraction, and has a half band width of an X-ray diffraction peak of 1.41° or less at 33.90° of the Bragg angle (2θ±0.20°) in CuKα characteristic X-ray diffraction.

Description

  The present invention relates to an electrophotographic photosensitive member, a manufacturing method thereof, a process cartridge, and an electrophotographic apparatus.

  As an electrophotographic photoreceptor used in an electrophotographic apparatus, an electrophotographic photoreceptor obtained by forming an undercoat layer and a photosensitive layer on a support in this order is used.

  For the purpose of improving the conductivity, there is a technique of incorporating metal oxide particles in the undercoat layer. Patent Document 1 discloses a technique using titanium oxide particles covered with oxygen-deficient tin oxide in an undercoat layer. Patent Document 2 discloses a technique using barium sulfate particles coated with tin oxide on an undercoat layer. Patent Document 3 discloses a technique using rutile-type titanium oxide crystal particles having an average primary particle diameter of 3 nm or more and 9 nm or less containing tin in the undercoat layer.

JP 2007-47736 A Japanese Patent Laid-Open No. 06-208238 JP 2010-271705 A

  In recent years, with the diversification of the usage environment of electrophotographic apparatuses, there is a demand for an electrophotographic photosensitive member with less fluctuation in electrophotographic characteristics due to usage environment such as temperature and humidity.

  As a result of the study by the present inventors, in an electrophotographic photosensitive member having an undercoat layer containing metal oxide particles described in Patent Documents 1 to 3, when used in a high-temperature and high-humidity environment, moisture is oxidized by metal. It was found that the resistance of the undercoat layer was increased by adhering to the object particles. As a result, the accumulation of electrons occurs, and when the electrophotographic photosensitive member is repeatedly used in a high-temperature and high-humidity environment, the bright portion potential may be easily changed, and it has been found that there is room for further improvement.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an electrophotographic photoreceptor in which fluctuations in bright area potential are suppressed when images are formed repeatedly in a high temperature and high humidity environment, and a method for producing the electrophotographic photoreceptor. Another object of the present invention is to provide a process cartridge and an electrophotographic apparatus having the electrophotographic photosensitive member.

The present invention is an electrophotographic photoreceptor having a support, an undercoat layer formed on the support, and a photosensitive layer formed on the undercoat layer,
The undercoat layer contains a binder resin and composite particles;
The composite particles have core particles and tin oxide covering the core particles;
The tin oxide of the composite particle is
It has a peak at 33.90 ° of the Bragg angle (2θ ± 0.20 °) in CuKα characteristic X-ray diffraction, and the Bragg angle (2θ ± 0.20 °) in CuKα characteristic X-ray diffraction = 33.90 ° The electrophotographic photosensitive member is characterized in that the half width of the X-ray diffraction peak is 1.41 ° or less.

The present invention also relates to a method for producing an electrophotographic photosensitive member for producing an electrophotographic photosensitive member having a support, an undercoat layer formed on the support, and a photosensitive layer formed on the undercoat layer. The manufacturing method is
A step of preparing a coating solution for the undercoat layer containing the binder resin and the composite particles; and forming a coating film of the coating solution for the undercoat layer and drying the coating film to form the undercoat layer Having a process,
The composite particles have core particles and tin oxide covering the core particles;
The tin oxide of the composite particle is
Having a peak at 33.90 ° of the Bragg angle (2θ ± 0.20 °) in CuKα characteristic X-ray diffraction, and
A method for producing an electrophotographic photoreceptor, wherein the half-value width of an X-ray diffraction peak at a Bragg angle (2θ ± 0.20 °) = 33.90 ° in CuKα characteristic X-ray diffraction is 1.41 ° or less. is there.

  Further, the present invention integrally supports the electrophotographic photosensitive member and at least one means selected from the group consisting of a charging means, a developing means, a transfer means, and a cleaning means, and is detachable from the main body of the electrophotographic apparatus. It is a process cartridge characterized by being.

  The present invention also provides an electrophotographic apparatus comprising the above-described electrophotographic photosensitive member, and a charging unit, an exposing unit, a developing unit, and a transfer unit.

  According to the present invention, it is possible to provide an electrophotographic photosensitive member in which fluctuations in bright portion potential are suppressed when images are repeatedly formed in a high-temperature and high-humidity environment, and a method for manufacturing the electrophotographic photosensitive member. According to the present invention, a process cartridge and an electrophotographic apparatus having the electrophotographic photosensitive member can be provided.

1 is a diagram illustrating an example of a schematic configuration of an electrophotographic apparatus including a process cartridge having an electrophotographic photosensitive member. It is a figure explaining an example of a layer structure of an electrophotographic photosensitive member. 2 is an X-ray diffraction pattern of tin oxide-coated core material particles obtained in Example 1. FIG.

  The electrophotographic photosensitive member of the present invention has a support, an undercoat layer formed on the support, and a photosensitive layer formed on the undercoat layer. The photosensitive layer is formed by laminating a single layer type photosensitive layer containing a charge generation material and a charge transport material in a single layer, a charge generation layer containing a charge generation material and a charge transport layer containing a charge transport material. And a laminated photosensitive layer. A laminated photosensitive layer is preferred.

  FIG. 2 shows an example of the layer structure of the electrophotographic photosensitive member of the present invention. In FIG. 2A, 101 is a support, 102 is an undercoat layer, and 103 is a photosensitive layer. In FIG. 2B, 101 is a support, 102 is an undercoat layer, 104 is an intermediate layer, and 105 is a photosensitive layer.

  In the present invention, the undercoat layer of the electrophotographic photosensitive member contains a binder resin and composite particles, and the composite particles have core material particles and tin oxide covering the core material particles. And this composite particle has the following characteristics. That is, the tin oxide of the composite particles has a peak at 33.90 ° of the Bragg angle (2θ ± 0.20 °) in CuKα characteristic X-ray diffraction. Furthermore, the half width of the X-ray diffraction peak at a Bragg angle (2θ ± 0.20 °) = 33.90 ° in CuKα characteristic X-ray diffraction is 1.41 ° or less. The composite particles having the above characteristics are also referred to as “tin oxide-coated core material particles having a specific half width at a specific peak”.

  Tin oxide whose half-width of the X-ray diffraction peak at a Bragg angle (2θ ± 0.20 °) = 33.90 ° in CuKα characteristic X-ray diffraction is 1.41 ° or less is an average crystallite diameter of tin oxide. It means a certain level or more (approximately 6 nm or more).

  The present inventors consider the reason why fluctuations in the bright part potential are suppressed when the image is repeatedly formed under a high temperature and high humidity environment as described above.

  One of the factors that cause the bright part potential fluctuation is that the flow of electrons stays in the undercoat layer of the electrophotographic photosensitive member, and the bright part potential tends to fluctuate due to the retention of electrons. Tend. The conduction path of electrons in the undercoat layer may be conduction in the tin oxide-coated core material particles and conduction between the tin oxide-coated core material particles. Under high-temperature and high-humidity environment, moisture adsorbs on the surface of the tin oxide-coated core material particles, resulting in a decrease in conductivity between the tin oxide-coated core material particles, resulting in resistance fluctuations in the undercoat layer. It is speculated that stagnation tends to occur.

  The tin oxide-coated core material particle of the present invention has a peak at 33.90 ° of the Bragg angle (2θ ± 0.20 °) in CuKα characteristic X-ray diffraction, which is the CuKα characteristic X-ray diffraction of tin oxide (SnO). Is the peak. In the tin oxide-coated core material particles of the present invention, the half-value width of the X-ray diffraction peak at a Bragg angle (2θ ± 0.20 °) = 33.90 ° in CuKα characteristic X-ray diffraction is 1.41 ° or less. . More preferably, the half width of the X-ray diffraction peak is 0.50 ° or more and 1.40 ° or less. Further, preferably, the half width of the X-ray diffraction peak is 0.80 ° or more and 1.30 ° or less.

  By setting the half-value width of the X-ray diffraction peak at a Bragg angle (2θ ± 0.20 °) = 33.90 ° of tin oxide to 1.41 ° or less, the average crystallite diameter of tin oxide is more than a certain value (approximately 6 nm) Above). When the average crystallite diameter of tin oxide is a certain value or more, the surface area (specific surface area) per unit mass of tin oxide is smaller than when the average crystallite diameter of tin oxide is small. Thereby, when the specific surface area becomes small, the proportion of conduction through the surface of tin oxide in the entire conduction path becomes small. Moreover, when the specific surface area is small, it is considered that the amount of moisture adsorbed on the surface of tin oxide per unit mass of the tin oxide-coated core material particles is reduced in a high temperature and high humidity environment. From the above, by reducing the specific surface area, resistance fluctuations in high-temperature and high-humidity environments are suppressed by reducing the rate of conduction through the surface of tin oxide and reducing the amount of moisture adsorbed on the surface of tin oxide. The bright part potential fluctuation is considered to be improved.

  For the measurement of the half-width of the X-ray diffraction peak, use the RIGTT Co., Ltd. sample horizontal strong X-ray diffractometer "RINT TTRII", and use the analysis software "JADE6" attached to the above-mentioned apparatus for the analysis. It is possible. The measurement conditions of the present invention are as follows: radiation source: CuKα, parallel beam optical system, voltage: 50 kV, current 300 mA, start angle: 30 °, end angle: 40 °, coefficient unit: Counts, step width: 0.01 °, Coefficient time: 3 seconds, divergent slit: open, divergent longitudinal restriction slit: 10 mm, scattering slit: open, light receiving slit: open. The sample was prepared by spreading tin oxide-coated core particles on a glass sample plate having a depth of 0.5 mm.

[Undercoat layer]
The undercoating layer has a binder resin and a tin oxide coated core having a half-value width of an X-ray diffraction peak at a Bragg angle (2θ ± 0.20 °) = 33.90 ° of tin oxide of 1.41 ° or less. Contains material particles.

The volume resistivity of the undercoat layer is more preferably 5.0 × 10 ¹³ Ω · cm or less. When the undercoat layer satisfies this volume resistivity, charge retention is suppressed during image formation, and residual potential is suppressed. On the other hand, the volume resistivity of the undercoat layer is preferably 1.0 × 10 ⁹ Ω · cm or more, and more preferably 1.0 × 10 ¹² Ω · cm or more. When the undercoat layer satisfies this volume resistivity, the amount of electric charge flowing in the undercoat layer becomes moderate, and the spots and fog when image formation is repeatedly performed in a high temperature and high humidity environment are suppressed.

  Examples of the core particles include organic resin particles, inorganic particles, and metal oxide particles. Tin oxide-coated core material particles having a half-value width of an X-ray diffraction peak at a Bragg angle (2θ ± 0.20 °) = 33.90 ° of tin oxide of 1.41 ° or less used tin oxide particles alone. Compared to the case, the effect of suppressing black spots when a high electric field is applied is excellent. From the viewpoint of coating with tin oxide, it is preferable to use inorganic particles and metal oxide particles as the core material particles. However, from the viewpoint of constituting the composite particles, it is preferable not to use tin oxide as the core material particles.

  From the viewpoint of uniformly coating tin oxide, it is preferable to use zinc oxide particles, titanium oxide particles, or barium sulfate particles as the core material particles.

From the viewpoint of adjusting the volume resistivity of the undercoat layer within the above range, the composite particles (tin oxide-coated core particles) have a powder resistivity (powder specific resistance) of 1.0 × 10 ¹ Ω · cm or more. It is preferably 1.0 × 10 ¹⁰ Ω · cm or less. Within the above range, the volume resistivity of the undercoat layer can be easily controlled within the above range.

  The tin oxide-coated core material particles can be mixed with two or more types of tin oxide-coated core material particles. In that case, in two or more types of tin oxide-coated core material particles, if the half-value width of the X-ray diffraction peak at a Bragg angle (2θ ± 0.20 °) = 33.90 ° of tin oxide is 1.41 ° or less Good.

  The mass ratio (coverage) of tin oxide is preferably 10% by mass or more and 60% by mass or less with respect to the total mass of the composite particles. More preferably, it is 15 mass% or more and 55 mass% or less.

In order to control the coverage of tin oxide, it is necessary to mix the tin raw materials necessary for producing tin oxide when producing composite particles. For example, in consideration of tin oxide (SnO ₂ ) generated from tin chloride (SnCl ₄ ), which is a tin raw material, it is necessary to control the coverage of tin oxide. Within the above range of the coverage of tin oxide, the powder resistivity of the composite particles can be easily controlled, and the coating of the core material particles with tin oxide tends to be uniform.

The powder resistivity of the composite particles is measured under a normal temperature and normal humidity (23 ° C./50% RH) environment. In the present invention, a resistance measuring device (trade name: Loresta GP) manufactured by Mitsubishi Chemical Corporation is used as the measuring device. The composite particles to be measured are hardened at a pressure of 500 kg / cm ² to obtain a pellet-shaped measurement sample. The applied voltage is 100V.

  The undercoat layer can be formed by forming a coating film of the coating solution for the undercoat layer obtained by dispersing the composite particles together with the binder resin in a solvent, and drying and / or curing the coating film. . Examples of the dispersion method include a method using a paint shaker, a sand mill, a ball mill, and a liquid collision type high-speed disperser.

  Examples of the binder resin used for the undercoat layer include phenol resin, polyurethane, polyamide, polyimide, polyamideimide, polyvinyl acetal, epoxy resin, acrylic resin, melamine resin, and polyester. These can be used alone or in combination of two or more.

  Among these, curable resins are preferable from the viewpoints of suppressing migration (melting) to other layers (for example, a photosensitive layer) and the dispersibility and dispersion stability of the composite particles. Among curable resins, phenol resin and polyurethane resin are preferable because they cause moderately large dielectric relaxation when dispersed with composite particles.

  Examples of the solvent used in the coating solution for the undercoat layer include alcohols such as methanol, ethanol, isopropanol, and 1-methoxy-2-propanol, ketones such as acetone, methyl ethyl ketone, and cyclohexanone, tetrahydrofuran, dioxane, ethylene glycol monomethyl ether, Examples include ethers such as propylene glycol monomethyl ether, esters such as methyl acetate and ethyl acetate, and aromatic hydrocarbons such as toluene and xylene.

  In the present invention, from the viewpoint of suppressing cracks, the mass ratio (P / B) between the tin oxide-coated core particles (P) and the binder resin (B) is from 1/1 to 4/1. preferable. Further, when it is within this range, the volume resistivity of the undercoat layer can be easily controlled.

  The thickness of the undercoat layer is preferably 10 μm or more and 40 μm or less, and more preferably 10 μm or more and 30 μm or less.

  In the present invention, FISCHERSCOPE mms manufactured by Fisher Instruments Co., Ltd. is used as a film thickness measuring device for each layer of the electrophotographic photosensitive member including the undercoat layer.

  The number average particle diameter of the tin oxide-coated core material particles is preferably 0.03 μm or more and 0.60 μm or less, and more preferably 0.05 μm or more and 0.40 μm or less. Within the above range, cracks are further suppressed, and black spots due to suppression of local charge injection into the photosensitive layer are reduced.

  In the present invention, the number average particle diameter D (μm) of the tin oxide-coated core material particles is determined as follows using a scanning electron microscope. Using a scanning electron microscope (trade name: S-4800) manufactured by Hitachi, Ltd., the particles to be measured are observed. From the images obtained by observation, 100 individual tin oxide coated core particles are obtained. Measure the particle size. And the arithmetic average of those is calculated and it is set as the number average particle diameter D (micrometer). The individual particle size was (a + b) / 2, where a is the longest side of the primary particles and b is the shortest side.

  The undercoat layer further has a peak at 33.90 ° of the Bragg angle (2θ ± 0.20 °) in CuKα characteristic X-ray diffraction, and the Bragg angle (2θ ± 0.20 °) = 33. It is preferable that tin oxide particles (tin oxide particles) having a half width of an X-ray diffraction peak at 90 ° of 1.41 ° or less are contained. As a result, an effect of further suppressing an increase in pattern memory and bright portion potential is observed. In the undercoat layer, the volume ratio between the tin oxide particles and the composite particles (tin oxide particles / composite particles) is preferably 1/1000 or more and 250/1000 or less. More preferably, it is 1/1000 or more and 150/1000 or less. This is considered that the conductive path is easily formed by the tin oxide particles entering the gaps where the conductive path formed by the composite particles in the undercoat layer is divided.

  The volume ratio of the tin oxide particles to the composite particles can be determined by FIB-SEM Slice & View after removing the undercoat layer of the electrophotographic photosensitive member by the FIB method.

The tin oxide particles and the composite particles are identified from the difference in contrast between slice and view of FIB-SEM. Thereby, the ratio of the volume of the tin oxide particles and the volume of the composite particles can be determined. In the present invention, the conditions of Slice & View are as follows.
Sample processing for analysis: FIB method Processing and observation apparatus: NVision40 manufactured by SII / Zeiss
Slice interval: 10 nm
Observation conditions:
Acceleration voltage: 1.0 kV
Sample tilt: 54 °
WD: 5mm
Detector: BSE detector Aperture: 60 μm, high current
ABC: ON
Image resolution: 1.25nm / pixel

Analysis region is carried out in vertical 2 [mu] m × horizontal 2 [mu] m, and integrating the information for each section, the vertical 2 [mu] m × horizontal 2 [mu] m × thickness 2μm _(V T = 8μm ³⁾ the volume _{V 1} of the above tin oxide particles per volume of the composite particles determine the V _2. The measurement environment is temperature: 23 ° C. and pressure: 1 × 10 ⁻⁴ Pa. In addition, Strata400S (sample inclination: 52 degrees) made from FEI can also be used as a processing and observation apparatus. Sampling is performed 10 times in the same manner, and 10 samples are obtained for measurement. The value obtained by dividing the average value of the volume V ₁ of the tin oxide particles per 8 μm ^{3 of} 10 points in total by V _T (8 μm ³ ) is the volume of the tin oxide particles in the undercoat layer of the electrophotographic photosensitive member to be measured. (V ₁ / V _T ). Further, the value obtained by dividing the average value of the volume V ₂ of the composite particles per 8 μm ^{3 of} 10 points in total by V _T (8 μm ³ ) is the volume of the composite particles in the undercoat layer of the electrophotographic photoreceptor to be measured. The value was (V ₂ / V _T ).
The particle area was obtained by image analysis from the information for each cross section. Image analysis was performed using the following image processing software.
Image processing software: Image-Pro Plus from Media Cybernetics

  From the viewpoint of suppressing interference fringes, the undercoat layer may contain a surface roughening agent. As the surface roughening material, resin particles having an average particle diameter of 1 μm or more and 5 μm or less (preferably 3 μm or less) are preferable. Examples of the resin particles include curable resin particles such as curable rubber, polyurethane, epoxy resin, alkyd resin, phenol resin, polyester, silicone resin, and acrylic-melamine resin. Among these, particles of silicone resin, acrylic melamine resin, and polymethyl methacrylate resin are preferable. The content of the surface roughening agent is preferably 1 to 80% by mass, more preferably 1 to 40% by mass with respect to the binder resin in the undercoat layer.

  The undercoat layer coating solution may contain a leveling agent for enhancing the surface properties of the undercoat layer. The undercoat layer may contain pigment particles for improving the concealability of the undercoat layer.

[Support]
As the support, those having conductivity (conductive support) are preferable, and for example, a metal support formed of a metal or an alloy such as aluminum, an aluminum alloy, and stainless steel can be used. In the case of using aluminum or an aluminum alloy, an aluminum tube manufactured by a manufacturing method including an extrusion process and a drawing process, or an aluminum pipe manufactured by a manufacturing method including an extrusion process and an ironing process can be used.

  An intermediate layer may be provided between the undercoat layer and the photosensitive layer for the purpose of providing an electrical barrier property in order to prevent charge injection from the undercoat layer to the photosensitive layer.

[Middle layer]
The intermediate layer can be formed by applying an intermediate layer coating solution containing a resin (binder resin) on the undercoat layer and drying it.

Examples of the resin (binder resin) used in the intermediate layer include polyvinyl alcohol, polyvinyl methyl ether, polyacrylic acids, methyl cellulose, ethyl cellulose, polyglutamic acid, polyamide, polyimide, polyamideimide, polyamic acid, melamine resin, epoxy resin, Examples thereof include polyurethane and polyglutamic acid ester.
The thickness of the undercoat layer is preferably from 0.1 μm to 2 μm.

  Further, in order to improve the flow of charge from the photosensitive layer to the support, the intermediate layer contains a polymer of a composition containing an electron transport material having a reactive functional group (polymerizable functional group) and a crosslinking agent. May be. Thereby, when forming a photosensitive layer on an intermediate | middle layer, it becomes possible to suppress the elution of the material of an intermediate | middle layer with respect to the solvent in the coating liquid for photosensitive layers.

  Examples of the electron transport material include a quinone compound, an imide compound, a benzimidazole compound, a cyclopentadienylidene compound, and the like.

  Examples of the reactive functional group include a hydroxy group, a thiol group, an amino group, a carboxyl group, or a methoxy group.

  In the intermediate layer, the content of the electron transport material having a reactive functional group in the composition is preferably 30% by mass or more and 70% by mass or less.

  Specific examples of the electron transport material having a reactive functional group are shown below.

In formulas (A1) to (A9), R ^{101 to} R ¹⁰⁶ , R ^{201 to} R ²¹⁰ , R ^{301 to} R ³⁰⁸ , R ^{401 to} R ⁴⁰⁸ , R ^{501 to} R ⁵¹⁰ , R ^{601 to} R ⁶⁰⁶ , R ^{701 to} R ⁷⁰⁸ , R ^{801 to} R ⁸¹⁰ , R ^{901 to} R ⁹⁰⁸ are each independently a monovalent group represented by the following formula (1) or (2), a hydrogen atom, a cyano group, a nitro group, a halogen atom, An alkoxycarbonyl group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic ring is shown. The substituent of the substituted alkyl group is an alkyl group, an aryl group, a halogen atom, or a carbonyl group. The substituent of the substituted aryl group or the substituted heterocyclic group is a halogen atom, a nitro group, a cyano group, an alkyl group, a halogen-substituted alkyl group, an alkoxy group, or a carbonyl group. Z ²⁰¹ , Z ³⁰¹ , Z ⁴⁰¹ , and Z ⁵⁰¹ each independently represent a carbon atom, a nitrogen atom, or an oxygen atom. When Z ²⁰¹ is an oxygen atom, R ²⁰⁹ and R ²¹⁰ are not present, and when Z ²⁰¹ is a nitrogen atom, R ²¹⁰ is not present. When Z ³⁰¹ is an oxygen atom, R ³⁰⁷ and R ³⁰⁸ are not present, and when Z ³⁰¹ is a nitrogen atom, R ³⁰⁸ is not present. When Z ⁴⁰¹ is an oxygen atom, R ⁴⁰⁷ and R ⁴⁰⁸ are not present, and when Z ⁴⁰¹ is a nitrogen atom, R ⁴⁰⁸ is not present. If Z ⁵⁰¹ is an oxygen atom absent ^{R 509} and ^{R 510,} when ^{Z 501} is a nitrogen atom ^{R 510} is absent. At least one of R ^{101 to} R ¹⁰⁶ , at least one of R ^{201 to} R ²¹⁰ , at least one of R ^{301 to} R ³⁰⁸ , at least one of R ^{401 to} R ⁴⁰⁸ , at least one of R ^{501 to} R ⁵¹⁰ , At least one of R ^{601 to} R ⁶⁰⁶ , at least one of R ^{701 to} R ⁷⁰⁸ , at least one of R ^{801 to} R ⁸¹⁰ , and at least one of R ^{901 to} R ⁹⁰⁸ are represented by the following formula (1) or (2): It is group shown by these.

  In formulas (1) and (2), at least one of A, B, C and D is a group having a substituent, and the substituent is a group consisting of a hydroxy group, a thiol group, an amino group, and a carboxyl group It is at least one group selected from more. l is 0 or 1.

A is a carboxyl group, a substituted or unsubstituted alkyl group having 1 to 6 atoms in the main chain, and a main chain derived by substituting one of the carbon atoms in the main chain of the substituted or unsubstituted alkyl group with an oxygen atom The number of atoms in the main chain derived by substituting one carbon atom in the main chain of a monovalent group having 1 to 6 atoms or a substituted or unsubstituted alkyl group with NR ¹ is 1 to 6. Indicates a valent group. R ¹ is a hydrogen atom or an alkyl group. The substituent of the substituted alkyl group is at least one selected from the group consisting of an alkyl group having 1 to 6 carbon atoms, a benzyl group, a phenyl group, a hydroxy group, a thiol group, an amino group, and a carboxyl group.

B is a substituted or unsubstituted alkylene group having 1 to 6 atoms in the main chain, or a main chain atom derived by replacing one of the carbon atoms in the main chain of the substituted or unsubstituted alkylene group with an oxygen atom A divalent group having 1 to 6 divalent groups, or a divalent group having 1 to 6 main chain atoms derived by replacing one of the carbon atoms in the main chain of a substituted or unsubstituted alkylene group with NR ² Indicates a group. R ² is a hydrogen atom or an alkyl group. The substituent of the substituted alkylene group is at least selected from the group consisting of an alkyl group having 1 to 6 carbon atoms, a benzyl group, an alkoxycarbonyl group, a phenyl group, a hydroxy group, a thiol group, an amino group, and a carboxyl group. One type.

  C represents a phenylene group, an alkyl-substituted phenylene group having 1 to 6 carbon atoms, a nitro-substituted phenylene group, a halogen-substituted phenylene group, or an alkoxy-substituted phenylene group. These groups may further have at least one group selected from the group consisting of a hydroxy group, a thiol group, an amino group, and a carboxyl group as a substituent.

  D represents a hydrogen atom or a substituted or unsubstituted alkyl group having 1 to 6 atoms in the main chain. The substituent of the substituted alkyl group is at least one selected from the group consisting of an alkyl group having 1 to 6 carbon atoms, a hydroxy group, a thiol group, an amino group, and a carboxyl group.

Specific examples of the electron transport material having a reactive functional group are shown below.
Table 1 shows specific examples of the compound represented by the formula (A1).

  Derivatives having the structure of (A1) (electron transport material derivatives) can be synthesized by the reaction of naphthalenetetracarboxylic dianhydride, which can be purchased from Tokyo Chemical Industry Co., Ltd. or Sigma-Aldrich Japan Co., Ltd., with a monoamine derivative. It is.

The compound represented by any one of (A1) to (A9) has a reactive functional group (hydroxy group, thiol group, amino group, carboxyl group, and methoxy group) that can be polymerized with a crosslinking agent. As methods for introducing these polymerizable functional groups into the derivatives having the structures of (A1) to (A9), there are the following two methods. The first method is a method in which a reactive functional group is directly introduced into a derivative having the structure of (A1) to (A9). The second method is a method of introducing a structure having a reactive functional group or a functional group that can be a precursor of the reactive functional group. As the second method, for example, based on the halide of the derivative having the structure of (A1) to (A9), for example, a cross-coupling reaction using a palladium catalyst and a base is used, and the functional group-containing aryl group is converted. There is a way to introduce. There is also a method of introducing a functional group-containing alkyl group using a cross-coupling reaction using a FeCl ₃ catalyst and a base. In addition, there is a method of introducing a hydroxyalkyl group or a carboxyl group by allowing an epoxy compound or CO ₂ to act after lithiation.

(Crosslinking agent)
Next, the crosslinking agent will be described.

  As the crosslinking agent, there can be used an electron transporting material having a reactive functional group and a compound that polymerizes or crosslinks with a thermoplastic resin having a reactive functional group described later. Specifically, compounds described in Shinzo Yamashita and Tosuke Kaneko “Crosslinking Agent Handbook” published by Taiseisha (1981) and the like can be used.

  In the present invention, the crosslinking agent is preferably an isocyanate compound. As the isocyanate compound, an isocyanate compound having a molecular weight in the range of 200 to 1300 is preferably used. Furthermore, it is preferable to have two or more isocyanate groups or blocked isocyanate groups. More preferably, it is 3-6. For example, triisocyanatebenzene, triisocyanatemethylbenzene, triphenylmethane triisocyanate, lysine triisocyanate, tolylene diisocyanate, hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, naphthalene diisocyanate diphenylmethane diisocyanate, isophorone diisocyanate, xylylene diisocyanate, 2,2 , 4-Trimethylhexamethylene diisocyanate, methyl-2,6-diisocyanatohexanoate, norbornane diisocyanate modified isocyanurate modified, biuret modified, allophanate modified, adduct modified with trimethylolpropane or pentaerythritol Etc. Among these, an isocyanurate modified body and an adduct modified body are more preferable.

The blocked isocyanate group is a group having a structure of —NHCOX ¹ (X ¹ is a protecting group). X ¹ may be any protecting group that can be introduced into an isocyanate group, but groups represented by the following formulas (H1) to (H6) are more preferable.

  Below, the specific example of an isocyanate compound is shown.

  Next, a thermoplastic resin having a reactive functional group (polymerizable functional group) will be described. As the thermoplastic resin having a reactive functional group, a thermoplastic resin having a structural unit represented by the following formula (D) (hereinafter also referred to as resin D) is preferable.

(In Formula (D), R ⁶¹ represents a hydrogen atom or an alkyl group. Y ¹ represents a single bond, an alkylene group or a phenylene group. W ¹ represents a hydroxy group, a thiol group, an amino group, a carboxyl group, Or a methoxy group.)

  Examples of the thermoplastic resin having a structural unit represented by the following formula (D) include polyvinyl butyral, acetal resin, polyolefin resin, polyester resin, polyether resin, and polyamide resin.

  The structural unit represented by the above formula (D) may be included in the following characteristic structure, or may be included other than the characteristic structure. Characteristic structures are shown in (E-1) to (E-5) below. (E-1) is a structural unit of acetal resin, (E-2) is a structural unit of polyolefin resin, (E-3) is a structural unit of polyester resin, (E-4) is a structural unit of polyether resin and ( E-5) is a structural unit of polyamide resin.

In formulas (E-1) to (E-5), R ^{21 to} R ²⁵ each independently represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group. R ^{26 to} R ³⁰ each independently represent a substituted or unsubstituted alkylene group or a substituted or unsubstituted arylene group. For example, in E-1, when R ²¹ is C ₃ H ₇ , it is butyral.

  The resin D can also be generally purchased. Examples of the resin that can be purchased include polyether polyol resins such as AQD-457 and AQD-473 manufactured by Nippon Polyurethane Industry Co., Ltd., Sannics GP-400 and GP-700 manufactured by Sanyo Chemical Industries, Ltd., and Hitachi Chemical. Industrial Co., Ltd., Phthalkid W2343, DIC Corporation, Watersol S-118, CD-520, Beckolite M-6402-50, M-6201-40IM, Harima Chemicals Co., Ltd., Hollidip WH-1188, Japan Polyester polyol resins such as Eupica ES3604 and ES6538, Polyacrylic polyol resins such as DIC Corporation, Bernock WE-300 and WE-304, and polyvinyl alcohols such as Kuraray Kuraraypoval PVA-203 Resin, BX-1, BM-1 manufactured by Sekisui Chemical Co., Ltd. Which polyvinyl acetal resin, polyamide resin such as Toraysin FS-350 manufactured by Nagase ChemteX Corporation, aqualic manufactured by Nippon Shokubai Co., Ltd., carboxyl group-containing resin such as Finelex SG2000 manufactured by Lead City, DIC ( Co., Ltd., polyamine resins such as racamide, and polythiol resins such as Toray Co., Ltd. QE-340M. Among these, polyvinyl acetal resins and polyester polyol resins are more preferable. The weight average molecular weight (Mw) of the resin D is more preferably in the range of 5000 to 300000.

  The volume of the composite particles relative to the total volume of the undercoat layer is preferably 0.2 to 2 times the volume of the electron transport material relative to the total volume of the composition of the intermediate layer. Within this range, the bright part potential fluctuation is improved under high temperature and high humidity. This is presumed to be because charge transfer from the charge generation layer to the intermediate layer and the undercoat layer is performed smoothly. These volume amounts are preferably those at a temperature of 23 degrees and 1 atmosphere.

(Photosensitive layer)
A photosensitive layer is provided on the undercoat layer or intermediate layer. The photosensitive layer is preferably a laminated photosensitive layer having a charge generation layer and a charge transport layer.

  Examples of the charge generating substance include azo pigments, phthalocyanine pigments, indigo pigments such as indigo and thioindigo, perylene pigments, polycyclic quinone pigments, squarylium dyes, pyrylium salts and thiapyrylium salts, triphenylmethane dyes, quinacridone pigments, and azurenium salts. Examples thereof include pigments, cyanine dyes, xanthene colors, quinoneimine dyes, and styryl dyes. Among these, metal phthalocyanines such as oxytitanium phthalocyanine, hydroxygallium phthalocyanine, and chlorogallium phthalocyanine are preferable.

  When the photosensitive layer is a laminated photosensitive layer, the charge generation layer is formed by applying a charge generation layer coating solution obtained by dispersing a charge generation material in a solvent together with a binder resin, and drying it. be able to. Examples of the dispersion method include a method using a homogenizer, an ultrasonic wave, a ball mill, a sand mill, an attritor, a roll mill, and the like.

  Examples of the binder resin used for the charge generation layer include polycarbonate, polyester, polyarylate, butyral resin, polystyrene, polyvinyl acetal, diallyl phthalate resin, acrylic resin, methacrylic resin, vinyl acetate resin, phenol resin, silicone resin, polysulfone. Styrene-butadiene copolymer, alkyd resin, epoxy resin, urea resin, vinyl chloride-vinyl acetate copolymer, and the like. These may be used alone or in combination as a mixture or copolymer.

  The mass ratio between the charge generation material and the binder resin (charge generation material: binder resin) is preferably in the range of 10: 1 to 1:10. More preferably, it is 5: 1 to 1: 1, and further 3: 1 to 1: 1.

  Examples of the solvent used in the charge generation layer coating solution include alcohols, sulfoxides, ketones, ethers, esters, aliphatic halogenated hydrocarbons, and aromatic compounds.

  The thickness of the charge generation layer is preferably from 0.1 μm to 5 μm, and more preferably from 0.1 μm to 2 μm.

  In addition, various sensitizers, antioxidants, ultraviolet absorbers, plasticizers, and the like can be added to the charge generation layer as necessary. In addition, in order to prevent the flow of charges from stagnation in the charge generation layer, the charge generation layer may contain an electron transport material (an electron accepting material such as an acceptor).

  When the photosensitive layer is a laminated photosensitive layer, the charge transport layer forms a coating film of the coating solution for the charge transport layer obtained by dissolving the charge transport material and the binder resin in a solvent, and then the coating film is dried. Can be formed.

It is preferable to reduce the dielectric polarization of the charge transport layer so that there is no dark decay after the downstream of the charging region, since the amount of dark decay during repeated use is small. Specifically, a binder resin having a dielectric constant of 3 or less is preferable. In addition, a charge transport material having a charge mobility of 1 × 10 ⁻⁶ cm / V · sec or less is preferable.

  Specific examples of the charge transport material include hydrazone compounds, styryl compounds, benzidine compounds, triarylamine compounds, and triphenylamine compounds.

  Specific examples of the binder resin include acrylic resin, styrene resin, polyester, polycarbonate, polyarylate, polysulfone, polyphenylene oxide, epoxy resin, polyurethane, and alkyd resin. In particular, polyester, polycarbonate, and polyarylate are preferable. These can be used alone or in combination as a mixture or copolymer.

  The mass ratio between the charge transport material and the binder resin (charge transport material: binder resin) is preferably in the range of 2: 1 to 1: 2.

  Examples of the solvent used in the charge transport layer coating solution include ketones such as acetone and methyl ethyl ketone, esters such as methyl acetate and ethyl acetate, ethers such as dimethoxymethane and dimethoxyethane, and aromatics such as toluene and xylene. Examples include hydrocarbons and hydrocarbons substituted with halogen atoms such as chlorobenzene, chloroform and carbon tetrachloride.

  The film thickness of the charge transport layer is preferably 3 μm or more and 40 μm or less, and more preferably 5 μm or more and 30 μm or less.

  In addition, an antioxidant, an ultraviolet absorber, and a plasticizer can be added to the charge transport layer as necessary.

  A protective layer may be provided on the photosensitive layer for the purpose of protecting the photosensitive layer.

  The protective layer can be formed by forming a coating film of a coating liquid for a protective layer containing a resin (binder resin), and drying and / or curing the coating film.

  Examples of the binder resin used for the protective layer include phenol resin, acrylic resin, polystyrene, polyester, polycarbonate, polyarylate, polysulfone, polyphenylene oxide, epoxy resin, polyurethane, alkyd resin, and siloxane resin. These can be used alone or in combination as a mixture or copolymer.

  The thickness of the protective layer is preferably 0.5 μm or more and 10 μm or less, and more preferably 1 μm or more and 8 μm or less.

  When applying the coating liquid for each of the above layers, for example, a dip coating method (dip coating method), a spray coating method, a spinner coating method, a roller coating method, a Meyer bar coating method, or a blade coating method should be used. Can do.

  FIG. 1 shows an example of a schematic configuration of an electrophotographic apparatus provided with a process cartridge having an electrophotographic photosensitive member.

  In FIG. 1, a cylindrical electrophotographic photosensitive member 1 is rotationally driven in a direction of an arrow about a shaft 2 at a predetermined peripheral speed.

  The peripheral surface of the electrophotographic photosensitive member 1 that is rotationally driven is uniformly charged to a predetermined positive or negative potential by a charging means (charging roller or the like) 3. Next, exposure light (image exposure light) 4 output from exposure means (image exposure means, not shown) such as slit exposure or laser beam scanning exposure is received. In this way, electrostatic latent images corresponding to the target image are sequentially formed on the peripheral surface of the electrophotographic photosensitive member 1. The voltage applied to the charging unit 3 may be only a DC voltage or a DC voltage on which an AC voltage is superimposed.

  The electrostatic latent image formed on the peripheral surface of the electrophotographic photosensitive member 1 is developed with toner of the developing means 5 to become a toner image. Next, the toner image formed on the peripheral surface of the electrophotographic photosensitive member 1 is transferred to a transfer material (such as paper) P by a transfer bias from a transfer unit (such as a transfer roller) 6. The transfer material P is fed from a transfer material supply means (not shown) between the electrophotographic photoreceptor 1 and the transfer means 6 (contact portion) in synchronization with the rotation of the electrophotographic photoreceptor 1.

  The transfer material P that has received the transfer of the toner image is separated from the peripheral surface of the electrophotographic photosensitive member 1 and is introduced into the fixing means 8 to receive the image fixing, and is printed out of the apparatus as an image formed product (print, copy). Be out.

  The peripheral surface of the electrophotographic photosensitive member 1 after the transfer of the toner image is subjected to removal of residual toner by a cleaning means (cleaning blade or the like) 7. Further, after being subjected to charge removal processing by pre-exposure light 11 from a pre-exposure means (not shown), it is repeatedly used for image formation. When the charging unit is a contact charging unit, pre-exposure is not always necessary.

  Among the components selected from the above-described electrophotographic photosensitive member 1, charging unit 3, developing unit 5, transfer unit 6, cleaning unit 7 and the like, a plurality of components are selected, and these are stored in a container and integrated as a process cartridge. It may be configured to be coupled to. The process cartridge may be configured to be detachable from the main body of the electrophotographic apparatus. In FIG. 1, an electrophotographic photosensitive member 1, a charging unit 3, a developing unit 5 and a cleaning unit 7 are integrally supported to form a cartridge, and an electrophotographic apparatus is provided using a guide unit 10 such as a rail of the electrophotographic apparatus main body. The process cartridge 9 is detachable from the main body.

  Hereinafter, the present invention will be described in more detail with reference to specific examples. However, the present invention is not limited to these. “Part” shown below means “part by mass”.

[Production example of tin oxide coated core particles]
The tin oxide-coated core material particles described in the examples can be produced as follows. In accordance with the examples, the type of core material particles of composite particles, the type and amount of dopant, and the amount of sodium stannate were changed. Furthermore, in order to control the resistance, the amount of oxygen vacancies was controlled by adjusting the firing atmosphere.

1050 g of titanium oxide particles (spherical, average primary particle size 160 nm) dispersed in 4000 cm ³ of pure water were put into a mother liquor tank having a capacity of 10,000 cm ³ . Pure water was further added to the mother liquor until it reached 9000 cm ³ .

After 872 g of sodium stannate was added to the mother liquor and the liquid temperature was raised to 70 ° C., it was circulated in the apparatus for 1 hour for preliminary dispersion. In preliminary dispersion, ultrasonic treatment was performed with an ultrasonic generator (570 W, 40 kHz). While this mother liquor was circulated, a 20% dilute sulfuric acid aqueous solution (mass basis) was added until the pH reached 2-4. In this way, after obtaining the slurry, the slurry was washed until the electric conductivity became 500 μS / cm or less, and then subjected to Nutsche filtration to obtain a cake. This cake was dried in air at 150 ° C. for 10 hours. Next, the dried cake was pulverized, and the pulverized powder was baked at 450 ° C. for 30 minutes in a 1% by volume H ₂ / N ₂ atmosphere. Thus, the intended tin oxide-coated titanium oxide particles 1 were obtained. The tin oxide-coated titanium oxide particles 1 had a peak at 33.90 ° of the Bragg angle (2θ ± 0.20 °) in CuKα characteristic X-ray diffraction, and had a characteristic peak of tin oxide. FIG. 1 shows CuKα characteristic X-ray diffraction of the tin oxide-coated titanium oxide particles 1 obtained. The full width at half maximum of the X-ray diffraction peak at a Bragg angle (2θ ± 0.20 °) = 33.90 ° in CuKα characteristic X-ray diffraction was 1.049 °.

  The peak in CuKα characteristic X-ray diffraction can also be measured by peeling off the photosensitive layer of the electrophotographic photosensitive member and, if necessary, the intermediate layer, scraping the undercoat layer, and using the shaved undercoat layer. . It is also possible to use a powder of the same material as the undercoat layer.

[Example 1]
As a support, an aluminum cylinder (conductive support) having a diameter of 24 mm and a length of 261 mm was used.

Tin oxide-coated titanium oxide particles 1 (powder resistivity: 2.3 × 10 ¹ Ω · cm, tin oxide coverage 35%, number average particle size: 200 nm, half-value width of X-ray diffraction peak: 1.049 ° 219 copies,
146 parts of a phenolic resin (trade name: Priorofen J-325, manufactured by Dainippon Ink & Chemicals, Inc., resin solid content: 60%) as a binder resin, and
106 parts of 1-methoxy-2-propanol as a solvent
A dispersion was prepared by putting in a sand mill using 420 parts of glass beads having a diameter of 1.0 mm, and performing a dispersion treatment under the conditions of a rotational speed of 2000 rpm, a dispersion treatment time of 4 hours, and a cooling water set temperature of 18 ° C. The glass beads were removed from the dispersion with a mesh. Thereafter, 23.7 parts of silicone resin particles (trade name: Tospearl 120, manufactured by Momentive Performance Materials, average particle diameter of 2 μm) were added to the dispersion as a surface roughening agent. Furthermore, 0.024 parts of silicone oil as a leveling agent (trade name: SH28PA, manufactured by Toray Dow Corning Co., Ltd.), 6 parts of methanol, and 6 parts of 1-methoxy-2-propanol are added and stirred. Thus, an undercoat layer coating solution was prepared. This undercoat layer coating solution was dip-coated on the support to form a coating film, and the coating film was dried at 145 ° C. for 30 minutes to form an undercoat layer having a thickness of 30 μm.

  Next, 4.5 parts of N-methoxymethylated nylon (trade name: Toresin EF-30T, manufactured by Nagase ChemteX Corporation) and copolymer nylon resin (trade name: Amilan CM8000, manufactured by Toray Industries, Inc.) An intermediate layer coating solution was prepared by dissolving 5 parts in a mixed solvent of 65 parts of methanol / 30 parts of n-butanol. This intermediate layer coating solution was dip coated on the undercoat layer to form a coating film, and the coating film was dried at 70 ° C. for 6 minutes to form an intermediate layer having a thickness of 0.65 μm.

  Next, crystalline gallium phthalocyanine crystals (charge generation materials) having peaks at 7.4 ° and 28.1 ° with a Bragg angle 2θ ± 0.2 ° in CuKα characteristic X-ray diffraction were prepared. 4 parts of this hydroxygallium phthalocyanine crystal and 0.04 part of the compound represented by the following formula (A) are added to 100 parts of cyclohexanone with polyvinyl butyral resin (trade name: ESREC BX-1, manufactured by Sekisui Chemical Co., Ltd.) 2 Part was added to the dissolved solution. This was dispersed for 1 hour in an atmosphere of 23 ± 3 ° C. in a sand mill apparatus using glass beads having a diameter of 1 mm. After dispersion, 100 parts of ethyl acetate was added to prepare a charge generation layer coating solution. This coating solution for charge generation layer was dip coated on the undercoat layer to form a coating film, and the coating film was dried at 90 ° C. for 10 minutes to form a charge generation layer having a thickness of 0.20 μm. .

Next, 50 parts of an amine compound represented by the following formula (B) (charge transporting substance), 50 parts of an amine compound represented by the following formula (C) (charge transporting substance), and a polycarbonate resin (trade name:
A coating solution for a charge transport layer was prepared by dissolving 100 parts of Iupilon Z400 (manufactured by Mitsubishi Gas Chemical Co., Ltd.) in a mixed solvent of 650 parts of chlorobenzene and 150 parts of dimethoxymethane. After storing the charge transport layer coating solution for 1 day, the charge transport layer coating solution is dip coated on the charge generation layer to form a coating film, and the coating film is dried at 110 ° C. for 30 minutes, A charge transport layer having a thickness of 21 μm was formed. Thus, an electrophotographic photosensitive member having a support, an undercoat layer, an intermediate layer, a charge generation layer, and a charge transport layer was formed.

  Next, evaluation will be described.

<Evaluation of light portion potential fluctuation during repeated use>
As an evaluation apparatus, a color laser beam printer (trade name: CP4525, modified so that the process speed is variable) manufactured by Hewlett-Packard Co., Ltd. was used. The above-described electrophotographic photosensitive member was mounted on the drum cartridge of this evaluation apparatus and evaluated as follows. The evaluation apparatus was installed in a high-temperature and high-humidity environment with a temperature of 30 ° C. and a humidity of 80% RH.

For the surface potential of the electrophotographic photosensitive member, the developing cartridge is removed from the evaluation apparatus, a potential probe (trade name: model6000B-8, manufactured by Trek) is fixed thereto, and a surface potential meter (model 344: manufactured by Trek) is used. And measured. In the potential measuring device, a potential measuring probe is arranged at the developing position of the developing cartridge, and the position of the potential measuring probe with respect to the electrophotographic photosensitive member is the gap between the center of the electrophotographic photosensitive member in the axial direction and the surface of the electrophotographic photosensitive member. Was 3 mm. As charging conditions, an applied bias at which the surface potential (dark portion potential) of the electrophotographic photosensitive member was 600 V was adjusted. Moreover, as the exposure conditions, the exposure conditions were adjusted to be 0.4 μJ / cm ² .

  Next, evaluation will be described. Each electrophotographic photosensitive member was evaluated under the charging conditions and exposure conditions set initially.

First, the electrophotographic photosensitive member is stored for 24 hours in an environment of a temperature of 50 ° C. and a humidity of 95% RH. Next, it is stored for 24 hours in an environment of temperature 30 ° C. and humidity 80% RH. After storage, the bright part potential of the electrophotographic photosensitive member when exposed under the exposure condition of 0.4 μJ / cm ² is measured. Thereafter, the electrophotographic photosensitive member is mounted on the developing cartridge and attached to the evaluation apparatus, and the electrophotographic photosensitive member is repeatedly used by passing 15000 sheets. The printing rate used for passing 15000 sheets is 4%. In addition, after 15,000 sheets have been output, a pause after outputting two sheets is repeated. The process speed for repeated use is 0.3 s / time for the electrophotographic photosensitive member.

After passing 15,000 sheets, the bright part potential of the electrophotographic photosensitive member when exposed under the exposure condition of 0.4 μJ / cm ² is measured. The difference between the initial value of the bright part potential and the value of the bright part potential after passing 15000 sheets is defined as the bright part potential fluctuation. The results are shown in Table 2.

[Example 2]
In the production example of tin oxide-coated titanium oxide particles, after adding a 20% dilute sulfuric acid aqueous solution (mass basis) until the pH becomes 2 to 4, neutralization and adding a step of adding aluminum chloride, powder resistance 1.3 × 10 ⁷ Ω · cm of tin oxide-coated titanium oxide particles were obtained. An electrophotographic photoreceptor is produced in the same manner as in Example 1 except that in the undercoat layer of Example 1, the tin oxide-coated titanium oxide particles are changed to the tin oxide-coated titanium oxide particles thus obtained and no intermediate layer is formed. did. The half width of the X-ray diffraction peak of the tin oxide-coated titanium oxide particles was 1.022 °. Table 2 shows the values of the light portion potential fluctuation.

Example 3
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that an intermediate layer was formed as follows on the undercoat layer of Example 1.

  8 parts of exemplary compound A101, 10 parts of isocyanate compound (B1) blocked with the group represented by formula (1), 0.1 part of zinc octylate (II), butyral resin (KS-5, Sekisui Chemical Co., Ltd.) 2 parts) was dissolved in a mixed solvent of 100 parts of dimethylacetamide and 100 parts of methyl ethyl ketone to prepare an intermediate layer coating solution. This intermediate layer coating solution is dip coated on the undercoat layer to form a coating film, and the coating film is heated at 160 ° C. for 30 minutes to be cured (polymerized), whereby an intermediate layer having a film thickness of 0.5 μm. Formed. Table 2 shows the values of the light portion potential fluctuation.

Example 4
In the undercoat layer of Example 1, the core material particles of the tin oxide-coated titanium oxide particles were changed from titanium oxide particles to barium sulfate particles. Other than that, an undercoat layer was formed in the same manner as in Example 1 to produce an electrophotographic photosensitive member. The half width of the X-ray diffraction peak of the tin oxide-coated barium sulfate particles was 1.075 °. Table 2 shows the values of the light portion potential fluctuation.

Example 5
In the undercoat layer of Example 1, the core material particles of the tin oxide-coated titanium oxide particles were changed from titanium oxide particles to zinc oxide particles. Other than that, an undercoat layer was formed in the same manner as in Example 1 to produce an electrophotographic photosensitive member. The half width of the X-ray diffraction peak of the tin oxide-coated zinc oxide particles was 1.091 °. Table 2 shows the values of the light portion potential fluctuation.

Example 6
In the undercoat layer of Example 1, the core material particles of the tin oxide-coated titanium oxide particles were changed from titanium oxide particles to aluminum oxide particles. Other than that, an undercoat layer was formed in the same manner as in Example 1 to produce an electrophotographic photosensitive member. The half width of the X-ray diffraction peak of the tin oxide-coated aluminum oxide particles was 1.121 °. Table 2 shows the values of the light portion potential fluctuation.

Example 7
Example 1 except that the half-width of the X-ray diffraction peak was changed to 0.839 ° by increasing the H ₂ concentration in the production of tin oxide-coated titanium oxide particles and firing in the undercoat layer of Example 1. An undercoat layer was formed in the same manner as described above to produce an electrophotographic photoreceptor. Table 2 shows the values of the light portion potential fluctuation.

Example 8
Example 1 except that the half-value width of the X-ray diffraction peak was changed to 1.398 ° by reducing the H ₂ concentration in the production of tin oxide-coated titanium oxide particles in the undercoat layer of Example 1 and firing. An undercoat layer was formed in the same manner as described above to produce an electrophotographic photoreceptor. Table 2 shows the values of the light portion potential fluctuation.

Example 9
In the tin oxide-coated titanium oxide particles of Example 1, the ultrasonic treatment at the time of preliminary dispersion in the production of tin oxide-coated titanium oxide particles was stopped, so that the tin oxide-coated titanium oxide having a half-value width of 1.434 ° of the X-ray diffraction peak Particles were made. In the undercoat layer of Example 1, tin oxide-coated titanium oxide particles having a half width of 1.434 ° of the X-ray diffraction peak, and tin oxide having a half width of 1.075 ° of the X-ray diffraction peak prepared in Example 4 Mixed with coated barium sulfate particles. Other than that, an undercoat layer was formed in the same manner as in Example 1 to produce an electrophotographic photosensitive member. The half width of the X-ray diffraction peak of the mixed particles was 1.384 °. Table 2 shows the values of the light portion potential fluctuation.

Example 10
In the undercoat layer of Example 1, the undercoat layer was changed in the same manner as in Example 1 except that the tin oxide-coated titanium oxide particles having an X-ray diffraction peak half width of 1.049 ° were changed from 218 parts to 44 parts. To form an electrophotographic photosensitive member. Table 2 shows the values of the light portion potential fluctuation.

Example 11
In the undercoat layer of Example 1, the undercoat layer was changed in the same manner as in Example 1 except that the tin oxide-coated titanium oxide particles having an X-ray diffraction peak half width of 1.049 ° were changed from 218 parts to 88 parts. To form an electrophotographic photosensitive member. Table 2 shows the values of the light portion potential fluctuation.

Example 12
In the undercoat layer of Example 1, the undercoat layer was changed in the same manner as in Example 1 except that the tin oxide-coated titanium oxide particles having an X-ray diffraction peak half width of 1.049 ° were changed from 218 parts to 704 parts. To form an electrophotographic photosensitive member. Table 2 shows the values of the light portion potential fluctuation.

Example 13
In the undercoat layer of Example 1, the undercoat layer was the same as in Example 1 except that the tin oxide-coated titanium oxide particles having an X-ray diffraction peak half width of 1.049 ° were changed from 218 parts to 792 parts. To form an electrophotographic photosensitive member. Table 2 shows the values of the light portion potential fluctuation.

Example 14
In the subbing layer of Example 1, Example 1 except that the mass ratio of tin oxide to tin oxide-coated titanium oxide particles was changed from 35% by mass to 5% by mass by reducing the addition amount of sodium stannate. Similarly, an undercoat layer was formed to produce an electrophotographic photosensitive member. The half width of the X-ray diffraction peak of the tin oxide-coated titanium oxide particles was 0.945 °. Table 2 shows the values of the light portion potential fluctuation.

Example 15
In the subbing layer of Example 1, Example 1 except that the mass ratio of tin oxide to tin oxide-coated titanium oxide particles was changed from 35% by mass to 10% by mass by reducing the addition amount of sodium stannate. Similarly, an undercoat layer was formed to produce an electrophotographic photosensitive member. The half width of the X-ray diffraction peak of the tin oxide-coated titanium oxide particles was 0.998 °. Table 2 shows the values of the light portion potential fluctuation.

Example 16
In the undercoat layer of Example 1, Example 1 except that the mass ratio of tin oxide to tin oxide-coated titanium oxide particles was changed from 35% by mass to 60% by mass by increasing the amount of sodium stannate added. Similarly, an undercoat layer was formed to produce an electrophotographic photosensitive member. The half width of the X-ray diffraction peak of the tin oxide-coated titanium oxide particles was 1.231 °. Table 2 shows the values of the light portion potential fluctuation.

Example 17
In the subbing layer of Example 1, Example 1 except that the mass ratio of tin oxide to tin oxide-coated titanium oxide particles was changed from 35% by mass to 65% by mass by reducing the addition amount of sodium stannate. Similarly, an undercoat layer was formed to produce an electrophotographic photosensitive member. The half width of the X-ray diffraction peak of the tin oxide-coated titanium oxide particles was 1.323 °. Table 2 shows the values of the light portion potential fluctuation.

Example 18
An undercoat layer was formed in the same manner as in Example 1 except that the film thickness of the undercoat layer of Example 1 was changed to 15 μm, and an electrophotographic photosensitive member was produced. Table 2 shows the values of the light portion potential fluctuation.

Example 19
An undercoat layer was formed in the same manner as in Example 1 except that the film thickness of the undercoat layer of Example 1 was changed to 40 μm, and an electrophotographic photosensitive member was produced. Table 2 shows the values of the light portion potential fluctuation.

Example 20
An intermediate layer was formed in the same manner as in Example 3 except that Example Compound A101 was changed to an electron transporting material represented by the following formula in the intermediate layer of Example 3 to produce an electrophotographic photoreceptor. Table 2 shows the values of the light portion potential fluctuation.

Example 21
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the undercoat layer of Example 1 was changed to the following and formed.

219 parts of the above tin oxide-coated titanium oxide particles 1, 11 parts of tin oxide particles 1 (powder resistivity: 1.2 × 10 ¹ Ω · cm, half-value width of X-ray diffraction peak: 1.030 °), binder resin 146 parts of phenolic resin product name as priofen J-325) and 106 parts of 1-methoxy-2-propanol as a solvent were put in a sand mill using 420 parts of glass beads having a diameter of 1.0 mm, and the number of revolutions : Dispersion treatment was performed under the conditions of 2000 rpm, dispersion treatment time: 4 hours, and set temperature of cooling water: 18 ° C. to prepare a dispersion. The glass beads were removed from the dispersion with a mesh. Thereafter, 23.7 parts of silicone resin particles (trade name: Tospearl 120) as a surface roughening imparting agent, 0.024 parts of silicone oil (trade name: SH28PA) as a leveling agent, 6 parts of methanol, and 1 A coating solution for an undercoat layer was prepared by adding 6 parts of -methoxy-2-propanol and stirring. This undercoat layer coating solution was dip-coated on the support to form a coating film, and the coating film was dried at 145 ° C. for 30 minutes to form an undercoat layer having a thickness of 30 μm. The tin oxide particles 1 have a peak at a Bragg angle (2θ ± 0.20 °) of 33.90 ° in CuKα characteristic X-ray diffraction, and a Bragg angle (2θ ± 0.20 °) = 33.90 °. The half width of the X-ray diffraction peak was 1.030 °.

  As described above, the volume ratio between the tin oxide particles 1 and the tin oxide-coated titanium oxide particles 1 is obtained using the slice & view of FIB-SEM. As a result, the volume ratio between the tin oxide particles 1 and the tin oxide-coated titanium oxide particles 1 is 50/1000.

[Example 22]
In Example 21, an electrophotographic photosensitive member was produced in the same manner as in Example 21 except that the tin oxide particles 1 were changed from 15 parts to 0.3 parts.

  As a result, the volume ratio between the tin oxide particles 1 and the tin oxide-coated titanium oxide particles 1 is 1/1000.

Example 23
An electrophotographic photosensitive member was produced in the same manner as in Example 22 except that the tin oxide-coated titanium oxide particles 1 were changed from 219 parts to 160 parts and the tin oxide particles 1 were changed from 15 parts to 40 parts in Example 22.

  As a result, the volume ratio between the tin oxide particles 1 and the tin oxide-coated titanium oxide particles 1 is 250/1000.

[Comparative Example 1]
Example 1 except that in the undercoat layer of Example 1, the half-width of the X-ray diffraction peak was changed to 1.434 ° by stopping the ultrasonic treatment at the time of preliminary dispersion in the production of tin oxide-coated titanium oxide particles. An undercoat layer was formed in the same manner as in Example 1 to produce an electrophotographic photoreceptor. Table 2 shows the values of the light portion potential fluctuation.

[Comparative Example 2]
In Example 9, the mixing ratio of tin oxide-coated titanium oxide particles having an X-ray diffraction peak half-value width of 1.434 ° and tin oxide-coated barium sulfate particles having an X-ray diffraction peak half-value width of 1.075 ° was determined. A mixed powder having a full width at half maximum of 1.452 ° was prepared. An undercoat layer was formed in the same manner as in Example 9 except that this mixed powder having a half-value width of 1.452 ° was used, and an electrophotographic photosensitive member was manufactured. Table 2 shows the values of the light portion potential fluctuation.

[Comparative Example 3]
In the undercoat layer of Example 2, except that the half-value width of the X-ray diffraction peak was changed to 1.422 ° by stopping the ultrasonic treatment at the time of preliminary dispersion in the production of tin oxide-coated titanium oxide particles. An undercoat layer was formed in the same manner as in Example 1 to produce an electrophotographic photoreceptor. Table 2 shows the values of the light portion potential fluctuation.

[Comparative Example 4]
In Comparative Example 1, an undercoat layer was formed in the same manner as in Example 1 except that the intermediate layer used in Example 20 was provided between the undercoat layer and the charge generation layer to produce an electrophotographic photosensitive member. . Table 2 shows the values of the light portion potential fluctuation.

[Comparative Example 5]
In the undercoat layer of Example 4, except that the half-width of the X-ray diffraction peak was changed to 1.448 ° by stopping the ultrasonic treatment at the time of preliminary dispersion during the production of tin oxide-coated barium sulfate particles. An undercoat layer was formed in the same manner as in Example 4 to produce an electrophotographic photoreceptor. Table 2 shows the values of the light portion potential fluctuation.

[Comparative Example 6]
Example 6 In the undercoat layer of Example 6, except that the half-width of the X-ray diffraction peak was changed to 1.522 ° by stopping the ultrasonic treatment at the time of preliminary dispersion in the production of tin oxide-coated aluminum sulfate particles. An undercoat layer was formed in the same manner as in Example 6 to produce an electrophotographic photoreceptor. Table 2 shows the values of the light portion potential fluctuation.

[Comparative Example 7]
In the undercoat layer of Example 1, tin oxide-coated titanium oxide particles were coated with tin oxide-coated titanium oxide described in Example 1 of Patent Document 1 (powder resistivity: 1.0 × 10 ² Ω · cm, tin oxide-coated). The mass ratio of tin oxide to titanium oxide particles was changed to a tin oxide coverage of 40%. Other than that, an undercoat layer was formed in the same manner as in Example 1 to produce an electrophotographic photosensitive member. The half width of the X-ray diffraction peak of this tin oxide-coated titanium oxide was 1.456 °. Table 2 shows the values of the light portion potential fluctuation.

[Comparative Example 8]
In the undercoat layer of Comparative Example 7, an undercoat layer was formed in the same manner as in Comparative Example 7 except that the mass ratio of tin oxide to the tin oxide-coated titanium oxide particles was changed to 35% to produce an electrophotographic photoreceptor. . The volume resistivity of the tin oxide-coated titanium oxide was 3.3 × 10 ² Ω · cm, and the half width of the X-ray diffraction peak was 1.434 °. Table 2 shows the values of the light portion potential fluctuation.

[Comparative Example 9]
In the undercoat layer of Comparative Example 7, an undercoat layer was formed in the same manner as in Comparative Example 7 except that the mass ratio of tin oxide to the tin oxide-coated titanium oxide particles was changed to 45% to produce an electrophotographic photoreceptor. . The volume resistivity of the tin oxide-coated titanium oxide was 2.3 × 10 ¹ Ω · cm, and the half width of the X-ray diffraction peak was 1.490 °. Table 2 shows the values of the light portion potential fluctuation.

[Comparative Example 10]
In the undercoat layer of Comparative Example 7, the volume resistivity of the tin oxide-coated titanium oxide particles was changed to 2.3 × 10 ⁷ Ω · cm by the same operation as in Example 2, and the intermediate layer was not formed. An undercoat layer was formed in the same manner as in Example 7 to produce an electrophotographic photoreceptor. The half width of the X-ray diffraction peak of the tin oxide-coated titanium oxide was 1.455 °. Table 2 shows the values of the light portion potential fluctuation.

[Comparative Example 11]
In the undercoat layer of Example 4, the tin oxide-coated barium sulfate particles were changed to tin oxide-coated barium sulfate particles described in Example 1 of Patent Document 2 (powder resistivity: 7.0 × 10 ² Ω · cm, tin oxide The mass ratio of tin oxide to the coated barium sulfate particles was changed to 50%. Otherwise, an undercoat layer was formed in the same manner as in Example 4 to produce an electrophotographic photosensitive member. Table 2 shows the values of the light portion potential fluctuation. The half-value width of the X-ray diffraction peak of the tin oxide-coated barium sulfate particles was 1.462 °.

[Comparative Example 12]
In the undercoat layer of Comparative Example 11, an undercoat layer was formed in the same manner as in Comparative Example 11 except that the mass ratio of tin oxide to the tin oxide-coated barium sulfate particles was changed to 35%, thereby producing an electrophotographic photoreceptor. . The volume resistivity of the tin oxide-coated titanium oxide was 1.3 × 10 ³ Ω · cm, and the half width of the X-ray diffraction peak was 1.438 °. Table 2 shows the values of the light portion potential fluctuation.

[Comparative Example 13]
In the undercoat layer of Example 1, an undercoat layer was formed in the same manner as in Example 1 except that 219 parts of tin oxide-coated titanium oxide particles were changed to 77 parts of tin oxide particles having an average particle diameter of 30 nm. A photographic photoreceptor was produced. When it was installed in an evaluation machine and charged, the dark part potential was not stable, and the bright part potential fluctuation evaluation was not possible. This is presumably because tin oxide aggregates due to the absence of the core material particles, and the charging ability is remarkably reduced.

DESCRIPTION OF SYMBOLS 1 Electrophotographic photoreceptor 2 Axis 3 Charging means 4 Exposure light 5 Developing means 6 Transfer means 7 Cleaning means 8 Fixing means 9 Process cartridge 10 Guide means P Transfer material

Claims (12)

An electrophotographic photosensitive member having a support, an undercoat layer formed on the support, and a photosensitive layer formed on the undercoat layer,
The undercoat layer contains a binder resin and composite particles;
The composite particles have core particles and tin oxide covering the core particles;
The tin oxide of the composite particle is
Having a peak at 33.90 ° of the Bragg angle (2θ ± 0.20 °) in CuKα characteristic X-ray diffraction, and
An electrophotographic photoreceptor, wherein a half-value width of an X-ray diffraction peak at a Bragg angle (2θ ± 0.20 °) = 33.90 ° in CuKα characteristic X-ray diffraction is 1.41 ° or less.   The electrophotographic photosensitive member according to claim 1, wherein the core material particles are zinc oxide particles, titanium oxide particles, or barium sulfate particles.   The electrophotographic photosensitive member according to claim 1, wherein a mass ratio of tin oxide to the composite particles is 10% by mass or more and 60% by mass or less.   The electrophotographic photosensitive member according to any one of claims 1 to 3, wherein a mass ratio of the composite particles and the binder resin in the undercoat layer is from 1/1 to 4/1. The undercoat layer further has a peak at 33.90 ° of the Bragg angle (2θ ± 0.20 °) in CuKα characteristic X-ray diffraction, and
5. The tin oxide particle according to claim 1, comprising tin oxide particles having a half-value width of an X-ray diffraction peak at a Bragg angle (2θ ± 0.20 °) = 33.90 ° in CuKα characteristic X-ray diffraction of 1.41 ° or less. 2. The electrophotographic photosensitive member according to item 1.   The electrophotographic photosensitive member according to claim 5, wherein a volume ratio of the tin oxide particles and the composite particles (tin oxide particles / composite particles) is 1/1000 or more and 250/1000 or less.   The electrophotographic photosensitive member according to claim 1, wherein the binder resin is a polyurethane resin or a phenol resin.   The electrophotographic photosensitive member according to claim 1, wherein the composite particles have a number average particle size of 0.03 μm or more and 0.60 μm or less.   In the composite oxide, the half width of the X-ray diffraction peak at a Bragg angle (2θ ± 0.20 °) = 33.90 ° in CuKα characteristic X-ray diffraction is 0.50 ° or more and 1.40 ° or less. The electrophotographic photosensitive member according to claim 1. A method for producing an electrophotographic photosensitive member for producing a support, an undercoat layer formed on the support, and a photosensitive layer formed on the undercoat layer, the production method But,
A step of preparing a coating solution for the undercoat layer containing the binder resin and the composite particles; and forming a coating film of the coating solution for the undercoat layer and drying the coating film to form the undercoat layer Having a process,
The composite particles have core particles and tin oxide covering the core particles;
The tin oxide of the composite particle is
Having a peak at 33.90 ° of the Bragg angle (2θ ± 0.20 °) in CuKα characteristic X-ray diffraction, and
A method for producing an electrophotographic photosensitive member, wherein the half-value width of an X-ray diffraction peak at a Bragg angle (2θ ± 0.20 °) = 33.90 ° in CuKα characteristic X-ray diffraction is 1.41 ° or less.   An electrophotographic apparatus integrally supporting the electrophotographic photosensitive member according to claim 1 and at least one means selected from the group consisting of a charging means, a developing means, a transfer means, and a cleaning means. A process cartridge that is detachable from the main unit. An electrophotographic apparatus comprising the electrophotographic photosensitive member according to any one of claims 1 to 9, and a charging unit, an exposure unit, a developing unit, and a transfer unit.