JP2019184775A - Electrophotographic photoreceptor, manufacturing method of electrophotographic photoreceptor, electrophotographic image formation device, electrophotographic image formation method, and process cartridge - Google Patents

Abstract

To provide an electrophotographic photoreceptor, a manufacturing method of the electrophotographic photoreceptor, an electrophotographic image formation device, an electrophotographic image formation method, and a process cartridge that can prevent the generation of an image memory for a long term and can prevent the generation of an image defect such as black potty and fog.SOLUTION: An electrophotographic photoreceptor of the present invention is produced by stacking an intermediate layer and photosensitive layer on a conductivity support body. The intermediate layer includes: surface modification metal oxide particles made of an electron transport property compound; and non-surface modification metal oxide particles.SELECTED DRAWING: None

Description

  The present invention relates to an electrophotographic photosensitive member, a method for manufacturing an electrophotographic photosensitive member, an electrophotographic image forming apparatus, an electrophotographic image forming method, and a process cartridge, and in particular, prevents occurrence of image memory and image defects over a long period of time. The present invention relates to an electrophotographic photoreceptor that can be used.

In recent years, electrophotographic image forming apparatuses have improved performance, high definition and high sensitivity. In addition, the toner used has been reduced in diameter, and improvement in image quality is expected. Furthermore, low energy is emphasized from the viewpoint of environmental load, and a development process with lower load is desired.
In the conventional development process, proximity charging, static elimination before cleaning, and irradiation of erase light were performed. However, these processes have been changed or eliminated. Was found to occur.
In particular, repeated memory (image memory) has become a problem due to a surface potential of the photoreceptor after exposure potential V _i increases. In order to solve this problem, a method of increasing the conductivity of the intermediate layer (also referred to as an undercoat layer or “UCL”) is used. Image defects such as spots and fog will occur.

  For example, Patent Document 1 proposes a method in which the intermediate layer has two layers and the highly conductive layer and the blocking layer have different functions with respect to the trade-off relationship between the repeated memory and the black spot / fog. Further, in Patent Document 2, the electrical characteristics are stabilized only by adding an electron transport material to the intermediate layer.

However, in the case of Patent Document 1, since the intermediate layer has a two-layer structure, it is necessary to apply the intermediate layer coating solution twice. With existing manufacturing equipment, it is necessary to modify the manufacturing line or extend the manufacturing time. Therefore, there is a problem that the cost of the photoconductor is increased.
Moreover, in the case of the said patent document 2, since the filler (metal oxide particle) is not used, there exists a problem that electroconductivity does not improve.

Japanese Patent Laying-Open No. 2015-0922227 JP 11-174705 A

  The present invention has been made in view of the above problems and situations, and a solution to the problem is to prevent the occurrence of image memory over a long period of time and to prevent the occurrence of image defects such as black spots and fog. An electrophotographic photosensitive member, a method for producing the electrophotographic photosensitive member, an electrophotographic image forming apparatus, an electrophotographic image forming method, and a process cartridge are provided.

In order to solve the above problems, the present inventor, in the process of examining the cause of the above problems, in the intermediate layer, the surface modified metal oxide particles by the electron transporting compound, and the non-surface modified metal oxide particles, It has been found that the inclusion thereof can provide an electrophotographic photosensitive member or the like that can prevent image memory from being generated over a long period of time and can prevent image defects from occurring.
That is, the said subject which concerns on this invention is solved by the following means.
1. An electrophotographic photoreceptor in which an intermediate layer and a photosensitive layer are laminated on a conductive support,
The electrophotographic photoreceptor, wherein the intermediate layer contains surface-modified metal oxide particles made of an electron-transporting compound and non-surface-modified metal oxide particles.

  2. 2. The electrophotographic photosensitive member according to item 1, wherein the surface-modified metal oxide particles or the non-surface-modified metal oxide particles contain any element of tin, titanium, and zinc.

［一般式（１）〜（４）及び一般式（７）中、Ｒ^１〜Ｒ^１６及びＲ^３１〜Ｒ^４０は、各々独立に、水素原子、置換基を有していてもよい炭素数１〜８のアルキル基、置換基を有していてもよい炭素数３〜１２のシクロアルキル基、置換基を有していてもよい炭素数１〜８のアルコキシ基、ハロゲン原子、置換基を有していてもよいアリール基、シアノ基、ニトロ基及びヒドロキシ基、置換基を有していてもよいカルボニル基からなる群より選択される基である。Ａｒ^１は、置換基を有していてもよいアリーレン基である。
一般式（５）中、Ｒ^１７及びＲ^１８は、各々独立に、水素原子、シアノ基及び置換基を有していてもよい炭素数１〜８のアルコキシカルボニル基からなる群より選択される基であって、少なくともいずれか一方が、シアノ基又は置換基を有していてもよい炭素数１〜８のアルコキシカルボニル基であり、Ｒ^１９〜Ｒ^２６は、各々独立に、水素原子、置換基を有していてもよい炭素数１〜８のアルキル基、置換基を有していてもよいアリール基、置換基を有していてもよい炭素数１〜８のアルコキシカルボニル基からなる群より選択される基である。Ｚは、炭素原子又は窒素原子である。
一般式（６）中、Ｒ^２７及びＲ^２８は、各々独立に、水素原子、置換基を有していてもよい炭素数１〜８のアルキル基、置換基を有していてもよい炭素数３〜１２のシクロアルキル基、置換基を有していてもよい炭素数１〜８のアルコキシ基、ハロゲン原子、置換基を有していてもよいアリール基、シアノ基及びニトロ基からなる群より選択される基である。ｐは、上記式（ｐ１）〜式（ｐ５）で表される４価の基のいずれかであって、置換基を有していてもよい炭素数１〜８のアルキル基、置換基を有していてもよい炭素数１〜８のアルコキシ基、ハロゲン原子、置換基を有していてもよい炭素数６〜１８のアリール基、シアノ基、ニトロ基及びヒドロキシ基からなる群より選択される少なくとも一つの置換基を有していてもよい。
一般式（７）及び一般式（８）中、Ｒ^２９、Ｒ^３０、Ｒ^４３及びＲ^４４は、各々独立に、水素原子、炭素数１〜８のアルキル基、置換基を有していてもよい炭素数３〜１２のシクロアルキル基、置換基を有していてもよい炭素数１〜８のアルコキシ基、置換基を有していてもよい炭素数６〜１８のアリール基、シアノ基及びニトロ基からなる群より選択される基であり、これらは互いに連結して環構造を有してもいてもよい。
一般式（７）中、Ｒ^４１及びＲ^４２は、各々独立に、水素原子、置換基を有していてもよい炭素数１〜８のアルキル基、置換基を有していてもよい炭素数３〜１２のシクロアルキル基、置換基を有していてもよい炭素数１〜８のアルコキシ基、ハロゲン原子からなる群より選択される基である。
一般式（８）及び一般式（９）中、Ｒ^４５、Ｒ^４６及びＲ^４７〜Ｒ^５０は、各々独立に、水素原子、炭素数１〜８のアルキル基、置換基を有していてもよい炭素数３〜１２のシクロアルキル基、置換基を有していてもよい炭素数１〜８のアルコキシ基、ハロゲン原子、置換基を有していてもよいアリール基、シアノ基、ニトロ基及びヒドロキシ基、置換基を有していてもよいヘテロアリール基からなる群より選択される基である。
一般式（８）及び一般式（９）中、Ｑ^１〜Ｑ^１２は、各々独立に、炭素原子又は窒素原子である。］ 3. 3. The electrophotographic photosensitive member according to item 1 or 2, wherein the electron transporting compound is an electron transporting compound represented by the following general formula (ETM).
AX: General formula (ETM)
[In the said general formula (ETM), A represents the mother frame | skeleton of an electron transport compound, and represents the mother frame | skeleton derived from the compound which has a structure represented by either of the following general formula (1)-(9). X represents _{-COOH, -Si (OCH 3) 3} , -Si (OC 2 H 5) 3, or -OH.
X is bonded to any ^one of the substituents R (R ^{1 to} R ⁵⁰ ) in the compounds represented by the following general formulas (1) to (9), and the substituent R at that time has 1 carbon atom. Represents an -8 alkylene group, an optionally substituted cycloalkylene group having 3 to 12 carbon atoms, and an optionally substituted ether group or ester group having 1 to 8 carbon atoms. ]

[In General Formulas (1) to (4) and General Formula (7), R ^{1 to} R ¹⁶ and R ^{31 to} R ⁴⁰ are each independently a hydrogen atom or a carbon number that may have a substituent 1 -8 alkyl group, C3-C12 cycloalkyl group which may have a substituent, C1-C8 alkoxy group which may have a substituent, a halogen atom and a substituent. And a group selected from the group consisting of an optionally substituted aryl group, cyano group, nitro group and hydroxy group, and optionally substituted carbonyl group. Ar ¹ is an arylene group which may have a substituent.
In General Formula (5), R ¹⁷ and R ¹⁸ are each independently a group selected from the group consisting of a hydrogen atom, a cyano group, and an optionally substituted alkoxycarbonyl group having 1 to 8 carbon atoms. And at least one of them is a cyano group or an optionally substituted alkoxycarbonyl group having 1 to 8 carbon atoms, and R ^{19 to} R ²⁶ each independently represents a hydrogen atom, a substituent From a group consisting of an alkyl group having 1 to 8 carbon atoms which may have an aryl group, an aryl group which may have a substituent, and an alkoxycarbonyl group having 1 to 8 carbon atoms which may have a substituent. The group to be selected. Z is a carbon atom or a nitrogen atom.
In General Formula (6), R ²⁷ and R ²⁸ each independently represent a hydrogen atom, an optionally substituted alkyl group having 1 to 8 carbon atoms, or an optionally substituted carbon number. From the group consisting of a 3-12 cycloalkyl group, an optionally substituted alkoxy group having 1 to 8 carbon atoms, a halogen atom, an optionally substituted aryl group, a cyano group, and a nitro group. The group to be selected. p is any of the tetravalent groups represented by the above formulas (p1) to (p5), and has an alkyl group having 1 to 8 carbon atoms and a substituent which may have a substituent. Selected from the group consisting of an optionally substituted alkoxy group having 1 to 8 carbon atoms, a halogen atom, an optionally substituted aryl group having 6 to 18 carbon atoms, a cyano group, a nitro group, and a hydroxy group. It may have at least one substituent.
In general formula (7) and general formula (8), R ²⁹ , R ³⁰ , R ⁴³ and R ⁴⁴ may each independently have a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or a substituent. A good cycloalkyl group having 3 to 12 carbon atoms, an optionally substituted alkoxy group having 1 to 8 carbon atoms, an optionally substituted aryl group having 6 to 18 carbon atoms, a cyano group, and These are groups selected from the group consisting of nitro groups, and these may be linked to each other to have a ring structure.
In General Formula (7), R ⁴¹ and R ⁴² each independently represent a hydrogen atom, an optionally substituted alkyl group having 1 to 8 carbon atoms, or an optionally substituted carbon number. It is a group selected from the group consisting of a 3-12 cycloalkyl group, an optionally substituted alkoxy group having 1 to 8 carbon atoms, and a halogen atom.
In general formula (8) and general formula (9), R ⁴⁵ , R ⁴⁶ and R ^{47 to} R ⁵⁰ may each independently have a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or a substituent. A good cycloalkyl group having 3 to 12 carbon atoms, an optionally substituted alkoxy group having 1 to 8 carbon atoms, a halogen atom, an optionally substituted aryl group, a cyano group, a nitro group, and It is a group selected from the group consisting of a hydroxy group and a heteroaryl group which may have a substituent.
In General Formula (8) and General Formula (9), Q ^{1 to} Q ¹² are each independently a carbon atom or a nitrogen atom. ]

  4). A in the general formula (ETM) is an oxadiazole derivative represented by the general formula (1), a quinone derivative represented by the general formula (4), and a tetracarboxylic acid represented by the general formula (6). 4. The electrophotographic photoreceptor according to item 3, which represents a mother skeleton derived from a derivative selected from acid diimide derivatives.

  5). The number average primary particle size of the surface-modified metal oxide particles or the non-surface-modified metal oxide particles is in the range of 5 to 200 nm, any one of items 1 to 4 The electrophotographic photoreceptor described in 1.

  6). The number average primary particle size of the surface-modified metal oxide particles or the non-surface-modified metal oxide particles is in the range of 10 to 100 nm, any one of items 1 to 5 The electrophotographic photoreceptor described in 1.

  7. The number average primary particle size of the surface modified metal oxide particles or the non-surface modified metal oxide particles is within a range of 10 to 50 nm, and the surface modified metal oxide particles and the non-surface modified metal oxide The electrophotographic photosensitive member according to any one of items 1 to 6, wherein the particles have different particle sizes.

  8). The electrophotographic photoreceptor according to any one of items 1 to 7, wherein the surface-modified metal oxide particles are unevenly distributed on the charge generation layer side.

  9. The electrophotographic photosensitive member according to any one of Items 1 to 8, wherein the intermediate layer is a curable resin layer.

［上記一般式（Ｉｎｔ）において、Ｒ_１０１及びＲ_１０２は、各々独立に、水素原子、置換基を有していてもよい炭素数１〜６のアルキル基、置換基を有していてもよい炭素数３〜６のシクロアルキル基、置換基を有していてもよいアリール基、ヒドロキシ基、カルボニル基からなる群より選択される基を表す。Ｒ_１０１及びＲ_１０２は、同じでも異なっていてもよい。］ 10. 0.01 ppm or more of a compound derived from any one of the compound in which the intermediate layer has a structure represented by the following general formula (Int), a compound containing a phosphorus element other than the compound, or a compound containing a sulfur element The electrophotographic photosensitive member according to item 9, which is contained.

[In the above general formula (Int), R ₁₀₁ and R ₁₀₂ each independently have a hydrogen atom, a C 1-6 alkyl group which may have a substituent, or a substituent. The group selected from the group which consists of a C3-C6 cycloalkyl group, the aryl group which may have a substituent, a hydroxy group, and a carbonyl group is represented. R ₁₀₁ and R ₁₀₂ may be the same or different. ]

11. An electrophotographic photosensitive member manufacturing method for manufacturing the electrophotographic photosensitive member according to any one of items 1 to 10,
The method for producing an electrophotographic photoreceptor, wherein the step of forming the intermediate layer includes a visible light curing step of curing with light having a wavelength of 400 nm or more.

  12 An electrophotographic image forming apparatus comprising the electrophotographic photosensitive member according to any one of Items 1 to 10.

  13. 13. The electrophotographic image forming apparatus according to item 12, wherein the charging means in the image forming apparatus is of a contact charging type.

  14 11. An electrophotographic image forming method using the electrophotographic photosensitive member according to any one of items 1 to 10.

  15. A process cartridge comprising the electrophotographic photosensitive member according to any one of items 1 to 10.

According to the above-mentioned means of the present invention, the generation of an image memory can be prevented over a long period of time, and the occurrence of image defects such as black spots and fog can be prevented, and the method for producing an electrophotographic photoreceptor An electrophotographic image forming apparatus, an electrophotographic image forming method, and a process cartridge can be provided.
The expression mechanism or action mechanism of the effect of the present invention is not clear, but is presumed as follows.
In the process of contact charging, the so-called “eraseless static elimination before cleaning” process (a process in which no photostatic elimination is performed after transfer), it has been found that the conventional photoreceptor repeatedly generates memory. Repeat memory, after a plurality of sheets (repeat) printed strip chart, printing a full solid image, a phenomenon appears as thin band part, is due to increase in the exposure potential V _i on the photoreceptor. This is presumed to be because negative charges are poorly discharged after exposure, negative charges accumulate in the intermediate layer, and gradually prevent hole generation in the charge generation layer.
From this hypothesis, as a solution to repeated memory, it is sufficient to lower the electrical resistance of the intermediate layer and increase the conductivity, but fog and black spots occur when the conductivity increases. The cause of the black spots is considered to be a local decrease in the charging potential V ₀ of the photosensitive member before exposure, and it is well known that it is likely to occur when the intermediate layer has high conductivity. The fog is caused by the same mechanism but not locally, and a decrease in the overall chargeability.
Conventional photoconductors have a prescription design aimed at a specific range where fog, black spots, and memory do not occur, but it is difficult to handle with a new process. Then, when the metal oxide particle surface-modified with the electron transport substance was used, the above trade-off relationship could be solved.
Photoconductors having an intermediate layer containing an electron transporting compound are already known, but since they have a two-layer structure, they need to be applied twice. Therefore, the cost of the photoconductor is increased.

Therefore, as a result of intensive studies, metal oxide particles (surface-modified metal oxide particles) surface-modified with an electron-transporting compound and metal oxide particles (non-surface-modified metal oxide particles) that are not surface-modified with an electron-transporting compound When a coating solution containing both of the above was prepared and applied, a layer that was internally biased into two layers was formed by one coating (surface-modified metal oxide particles were unevenly distributed on the charge generation layer side, Non-surface-modified metal oxide particles are unevenly distributed on the conductive support side).
The details of the mechanism by which such a configuration has produced good results have not been elucidated, but the following mechanism of action is considered.
As described above, it is possible to solve the trade-off between repeated memory and black spots and fog by incorporating an electron transporting compound-containing layer. Simply, alone is contained the surface modified metal oxide particles in the electron-transporting compound to the intermediate layer, a conductive intermediate layer is not improved so much, it does not lead to the solution to increase the exposure potential V _i. Therefore, if metal oxide particles that are not surface-modified with an electron transporting compound are applied together, the surface-modified metal oxide particles and the non-surface-modified metal are formed during film formation due to differences in the degree of hydrophobicity of the surface of the metal oxide particles. It is assumed that the oxide particles are unevenly distributed in the film.

Further, the negative charge generated in the charge generation layer by photoexcitation is usually negative in the intermediate layer even if the metal oxide particles are surface-modified with an electron transporting compound if the conductivity of the metal oxide particles is sufficiently high. Although the electric charge is discharged to the substrate without staying, the unintended negative charge generated by thermal excitation is blocked by the electron transport layer on the surface of the metal oxide particle and is transferred to the substrate via the metal oxide particle (filler). It is assumed that the discharge becomes difficult and recombines in the charge generation layer.
That is, it is speculated that the surface modification of the metal oxide particles with the electron transporting compound prevents the unintended charges generated by thermal excitation from being separated. Since there is a layer of metal oxide particles that are surface-modified with an electron-transporting compound, the charge generated by thermal excitation is blocked (retained in the charge-generating layer), and the metal oxide is surface-modified with a charge-transporting compound The negative charge due to photoexcitation that has passed (or moved) through the layer due to the physical particles can be quickly discharged to the substrate (that is, due to the metal oxide particles not surface-modified with the charge transporting compound) It is considered that the increase in exposure potential V _i is suppressed due to the presence of the layer).

In addition, it is estimated that charge generation due to thermal excitation of the charge generation layer occurs due to deterioration of the charge generation layer, variation in crystal shape (disturbance), deterioration during dispersion, impurities in the charge generation layer, Considering that preventing the deterioration of the charge generation layer also leads to suppression of fog and black spots, further investigations were made.
In general, there are many intermediate layers that are cured by heat using a polyamide resin, a thermosetting resin, or the like. However, rather than a thermosetting resin, a photo-curing resin is used, and further, curing with visible light (400 to 800 nm) rather than photo-curing using ultraviolet rays or an electron beam causes deterioration of the electron-transporting compound, It can be seen that the sensitivity reduction of the charge generation layer can be suppressed, and in the method for producing an electrophotographic photosensitive member of the present invention, in the step of forming the intermediate layer, curing is performed with light having a wavelength of 400 nm or more. This is presumed that side reactions are less likely to occur in photocuring than in heat curing.

Schematic sectional view showing an example of the image forming apparatus of the present invention

The electrophotographic photosensitive member of the present invention is an electrophotographic photosensitive member in which an intermediate layer and a photosensitive layer are laminated on a conductive support, and the intermediate layer includes surface-modified metal oxide particles made of an electron transporting compound and And non-surface-modified metal oxide particles.
This feature is a technical feature common to or corresponding to each of the following embodiments.

  As an embodiment of the present invention, the surface-modified metal oxide particles or the non-surface-modified metal oxide particles preferably contain any element of tin, titanium, and zinc from the viewpoint of electron transport properties.

  The electron transporting compound is preferably an electron transporting compound represented by the general formula (ETM) from the viewpoint of the surface treatment of the metal oxide particles.

  A in the general formula (ETM) is an oxadiazole derivative represented by the general formula (1), a quinone derivative represented by the general formula (4), or a tetracarboxylic acid represented by the general formula (6). It is preferable that at least one selected from acid diimide derivatives is easy in handling during the surface treatment of the metal oxide particles and can effectively block charges generated by thermal excitation.

  The number average primary particle size of the surface-modified metal oxide particles or the non-surface-modified metal oxide particles is preferably in the range of 5 to 200 nm in terms of electron transport properties and dispersibility, and in the range of 10 to 100 nm. More preferably, it is within.

  The number average primary particle size of the surface modified metal oxide particles or the non-surface modified metal oxide particles is within a range of 10 to 50 nm, and the surface modified metal oxide particles and the non-surface modified metal oxide It is preferable that the particles have different particle diameters from the viewpoint of improving the concealing power to the conductive support, suppressing moire and interference fringes, and eliminating pinholes that cause abnormal images.

  It is preferable that the surface-modified metal oxide particles are unevenly distributed on the charge generation layer side because unintentional movement of negative charges generated by thermal excitation generated in the charge generation layer can be easily prevented.

It is preferable that the intermediate layer is a curable resin layer in terms of suppressing deterioration of the charge transporting compound and a decrease in sensitivity of the charge generation layer.
In addition, a compound derived from any one of the compound in which the intermediate layer has a structure represented by the general formula (Int), a compound containing a phosphorus element other than the compound, or a compound containing a sulfur element is used. The content of 01 ppm or more is preferable from the viewpoint of excellent image memory resistance and wear resistance.

  The method for producing an electrophotographic photosensitive member of the present invention is characterized in that the step of forming the intermediate layer includes a visible light curing step of curing with light having a wavelength of 400 nm or more. As a result, deterioration of the electron transporting compound and reduction in sensitivity of the charge generation layer can be suppressed, which is effective in preventing the occurrence of image memory and the occurrence of image defects such as black spots and fog.

The electrophotographic photoreceptor of the present invention is suitably used for an electrophotographic image forming apparatus.
The charging means in the image forming apparatus of the present invention is preferably of a contact charging type from the viewpoint of charging uniformity of the photoreceptor.

  The electrophotographic photoreceptor of the present invention is suitably used for an electrophotographic image forming method. The electrophotographic photosensitive member of the present invention is preferably used for a process cartridge.

  Hereinafter, the present invention, its components, and modes and modes for carrying out the present invention will be described. In addition, in this application, "-" is used in the meaning which includes the numerical value described before and behind that as a lower limit and an upper limit.

[Outline of Electrophotographic Photosensitive Member of the Present Invention]
The electrophotographic photoreceptor of the present invention (hereinafter also simply referred to as “photoreceptor”) is an electrophotographic photoreceptor in which an intermediate layer and a photosensitive layer are laminated in this order on a conductive support, and the intermediate layer comprises And surface-modified metal oxide particles made of an electron transporting compound and non-surface-modified metal oxide particles.
In the electrophotographic photoreceptor of the present invention, an intermediate layer, a charge generation layer, a charge transport layer and a protective layer are laminated in this order on a conductive support, and the photosensitive layer is composed of the charge generation layer and the charge transport layer. It is preferable.

[Surface-modified metal oxide particles and non-surface-modified metal oxide particles]
The surface-modified metal oxide particles or non-surface-modified metal oxide particles according to the present invention preferably contain any element of tin, titanium, and zinc.
In the surface-modified metal oxide particles, the metal oxide particles containing the element are surface-modified with an electron transporting compound.

The electron transporting compound according to the present invention is preferably an electron transporting compound represented by the following general formula (ETM).
AX: General formula (ETM)
[In the said general formula (ETM), A represents the mother frame | skeleton of an electron transport compound, and represents the mother frame | skeleton derived from the compound which has a structure represented by either of the following general formula (1)-(9). X represents _{-COOH, -Si (OCH 3) 3} , -Si (OC 2 H 5) 3, or -OH.
X is bonded to any ^one of the substituents R (R ^{1 to} R ⁵⁰ ) in the compounds represented by the following general formulas (1) to (9), and the substituent R at that time has 1 carbon atom. Represents an -8 alkylene group, an optionally substituted cycloalkylene group having 3 to 12 carbon atoms, and an optionally substituted ether group or ester group having 1 to 8 carbon atoms. ]

In general formula (1), R ¹ and R ² are each independently a hydrogen atom, an optionally substituted alkyl group having 1 to 8 carbon atoms, or an optionally substituted carbon number. A cycloalkyl group having 3 to 12 carbon atoms, an alkoxy group having 1 to 8 carbon atoms which may have a substituent, a halogen atom, an aryl group which may have a substituent, a cyano group, a nitro group and a hydroxy group, It is a group selected from the group consisting of a carbonyl group which may have a substituent. Ar ¹ is an arylene group which may have a substituent.
Examples of the halogen atom represented by R ¹ and R ² include a chloro group (—Cl) and a bromo group (—Br).
Examples of the carbonyl group represented by R ¹ and R ² include —C (═O) —Ra (where Ra is a monovalent organic group) such as —C (═O) —ORb (where Ra is Monovalent organic group) and the like.
Examples of the substituent that R ¹ and R ² may have include an alkyl group, an aryl group, a carboxy group, a hydroxy group, and an alkoxysilyl group.
As the substituent which may have at Ar ^1, include those similar to the substituents that may have by R ₁ and R _2.

In General Formula (2), R ³ and R ⁴ are each independently a hydrogen atom, an optionally substituted alkyl group having 1 to 8 carbon atoms, or an optionally substituted carbon number. A cycloalkyl group having 3 to 12 carbon atoms, an alkoxy group having 1 to 8 carbon atoms which may have a substituent, a halogen atom, an aryl group which may have a substituent, a cyano group, a nitro group and a hydroxy group, It is a group selected from the group consisting of a carbonyl group which may have a substituent.
Examples of the halogen atom represented by R ³ and R ⁴ include a chloro group (—Cl) and a bromo group (—Br).
Examples of the carbonyl group represented by R ³ and R ⁴ include —C (═O) —Ra (wherein Rb is a monovalent organic group) such as —C (═O) —ORb (where Ra is Monovalent organic group) and the like.
Examples of the substituent that R ³ and R ⁴ may have include an alkyl group, an aryl group, a carboxy group, a hydroxy group, and an alkoxysilyl group.

In General Formula (3), R ^{5 to} R ⁸ are each independently a hydrogen atom, an optionally substituted alkyl group having 1 to 8 carbon atoms, or an optionally substituted carbon number. A cycloalkyl group having 3 to 12 carbon atoms, an alkoxy group having 1 to 8 carbon atoms which may have a substituent, a halogen atom, an aryl group which may have a substituent, a cyano group, a nitro group and a hydroxy group, It is a group selected from the group consisting of a carbonyl group which may have a substituent.
Examples of the halogen atom represented by R ^{5 to} R ⁸ include a chloro group (—Cl), a bromo group (—Br), and the like.
Examples of the carbonyl group represented by R ^{5 to} R ⁸ include —C (═O) —Ra (where Ra is a monovalent organic group) such as —C (═O) —ORb (where Rb is Monovalent organic group) and the like.
Examples of the substituent that R ^{5 to} R ⁸ may have include an alkyl group, an aryl group, a carboxy group, a hydroxy group, and an alkoxysilyl group.

In General Formula (4), R ^{9 to} R ¹⁶ are each independently a hydrogen atom, an optionally substituted alkyl group having 1 to 8 carbon atoms, or an optionally substituted carbon number. A cycloalkyl group having 3 to 12 carbon atoms, an alkoxy group having 1 to 8 carbon atoms which may have a substituent, a halogen atom, an aryl group which may have a substituent, a cyano group, a nitro group and a hydroxy group, It is a group selected from the group consisting of a carbonyl group which may have a substituent.
Examples of the halogen atom represented by R ^{9 to} R ¹⁶ include a chloro group (—Cl) and a bromo group (—Br).
Examples of the carbonyl group represented by R ^{9 to} R ¹⁶ include —C (═O) —Ra (where Ra is a monovalent organic group) such as —C (═O) —ORb (where Rb is Monovalent organic group) and the like.
Examples of the substituent that may be possessed by R ^{9 to} R ¹⁶ include an alkyl group, an aryl group, a carboxy group, a hydroxy group, and an alkoxysilyl group.

In General Formula (5), R ¹⁷ and R ¹⁸ are each independently a group selected from the group consisting of a hydrogen atom, a cyano group, and an optionally substituted alkoxycarbonyl group having 1 to 8 carbon atoms. And at least any one is a C1-C8 alkoxycarbonyl group which may have a cyano group or a substituent.
R ^{19 to} R ²⁶ each independently have a hydrogen atom, an optionally substituted alkyl group having 1 to 8 carbon atoms, an optionally substituted aryl group, or a substituent. Or a group selected from the group consisting of an alkoxycarbonyl group having 1 to 8 carbon atoms.
Z is a carbon atom or a nitrogen atom.
Examples of the substituent that may be contained in R ¹⁷ and R ¹⁸ and R ^{19 to} R ²⁶ include an alkyl group, an aryl group, a carboxy group, a hydroxy group, and an alkoxysilyl group.

In General Formula (6), R ²⁷ and R ²⁸ each independently represent a hydrogen atom, an optionally substituted alkyl group having 1 to 8 carbon atoms, or an optionally substituted carbon number. From the group consisting of a 3-12 cycloalkyl group, an optionally substituted alkoxy group having 1 to 8 carbon atoms, a halogen atom, an optionally substituted aryl group, a cyano group, and a nitro group. The group to be selected.
p is any of the tetravalent groups represented by the above formulas (p1) to (p5), and has an alkyl group having 1 to 8 carbon atoms and a substituent which may have a substituent. Selected from the group consisting of an optionally substituted alkoxy group having 1 to 8 carbon atoms, a halogen atom, an optionally substituted aryl group having 6 to 18 carbon atoms, a cyano group, a nitro group, and a hydroxy group. It may have at least one substituent.
Examples of the halogen atom represented by R ²⁷ and R ²⁸ include a chloro group (—Cl) and a bromo group (—Br).
Examples of the substituent that R ^27, R ^28, and p may have include an alkyl group, an aryl group, a carboxy group, a hydroxy group, and an alkoxysilyl group.

In General Formula (7), R ²⁹ and R ³⁰ are each independently a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an optionally substituted cycloalkyl group having 3 to 12 carbon atoms, or a substituent. A group selected from the group consisting of an alkoxy group having 1 to 8 carbon atoms which may have a group, an aryl group having 6 to 18 carbon atoms which may have a substituent, a cyano group and a nitro group. These may be linked to each other to have a ring structure.
R ^{31 to} R ⁴⁰ are each independently a hydrogen atom, an optionally substituted alkyl group having 1 to 8 carbon atoms, or an optionally substituted cycloalkyl group having 3 to 12 carbon atoms. An optionally substituted alkoxy group having 1 to 8 carbon atoms, a halogen atom, an optionally substituted aryl group, a cyano group, a nitro group and a hydroxy group, Or a group selected from the group consisting of good carbonyl groups.
R ⁴¹ and R ⁴² each independently represent a hydrogen atom, an alkyl group having 1 to 8 carbon atoms which may have a substituent, a cycloalkyl group having 3 to 12 carbon atoms which may have a substituent And a group selected from the group consisting of an alkoxy group having 1 to 8 carbon atoms which may have a substituent and a halogen atom.
Examples of the substituent that R ²⁹ , R ³⁰ , R ^{31 to} R ⁴⁰ , R ^41, and R ⁴² may have include an alkyl group, an aryl group, a carboxy group, a hydroxy group, and an alkoxysilyl group. .
Examples of the carbonyl group represented by R ^{31 to} R ⁴⁰ include —C (═O) —Ra (wherein Rb is a monovalent organic group) such as —C (═O) —ORb (where Ra is Monovalent organic group) and the like.
Examples of the halogen atom represented by R ^{31 to} R ⁴⁰ _, R ⁴¹ and R ⁴² include a chloro group (—Cl) and a bromo group (—Br).

In General Formula (8), R ⁴³ and R ⁴⁴ are each independently a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an optionally substituted cycloalkyl group having 3 to 12 carbon atoms, or a substituent. A group selected from the group consisting of an alkoxy group having 1 to 8 carbon atoms which may have a group, an aryl group having 6 to 18 carbon atoms which may have a substituent, a cyano group and a nitro group. These may be linked to each other to have a ring structure.
R ⁴⁵ and R ⁴⁶ each independently have a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an optionally substituted cycloalkyl group having 3 to 12 carbon atoms, or a substituent. From the group consisting of a good C1-C8 alkoxy group, a halogen atom, an optionally substituted aryl group, a cyano group, a nitro group and a hydroxy group, and an optionally substituted heteroaryl group The group to be selected.
Q ^{1 to} Q ⁶ are each independently a carbon atom or a nitrogen atom.
Examples of the substituent that R ⁴³ , R ⁴⁴ , R ⁴⁵ and R ⁴⁶ may have include an alkyl group, an aryl group, a carboxy group, a hydroxy group, and an alkoxysilyl group.
Examples of the halogen atom represented by R ⁴⁵ and R ⁴⁶ include a chloro group (—Cl) and a bromo group (—Br).

In general formula (9), R ^{47 to} R ⁵⁰ are each independently a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an optionally substituted cycloalkyl group having 3 to 12 carbon atoms, or a substituent. An optionally substituted alkoxy group having 1 to 8 carbon atoms, a halogen atom, an optionally substituted aryl group, a cyano group, a nitro group and a hydroxy group, and optionally having a substituent. It is a group selected from the group consisting of heteroaryl groups.
Q ^{7 to} Q ¹² are each independently a carbon atom or a nitrogen atom.
Examples of the substituent that R ^{47 to} R ⁵⁰ may have include an alkyl group, an aryl group, a carboxy group, a hydroxy group, and an alkoxysilyl group.
Examples of the halogen atom represented by R ^{47 to} R ⁵⁰ include a chloro group (—Cl) and a bromo group (—Br).

  In addition, the mother skeleton represented by the general formulas (1) and (2) is an oxadiazole derivative, and the mother skeleton represented by the general formulas (3) and (4) is a quinone derivative. The mother skeleton represented by the general formula (5) is a fluorene derivative, the mother skeleton represented by the general formula (6) is a tetracarboxylic acid diimide derivative, and the general formula (7) to The mother skeleton represented by (9) is a silole derivative.

  A in the general formula (ETM) is an oxadiazole derivative represented by the general formula (1), a quinone derivative represented by the general formula (4), and a tetracarboxylic acid represented by the general formula (6). Representing a dielectric-derived mother skeleton selected from acid diimide derivatives is preferred in terms of availability or handling during surface treatment.

Specific examples of the electron transporting compound represented by the general formula (ETM) are shown below.

(Synthesis Example of Oxadiazole Derivatives Represented by General Formulas (1) and (2))
Examples of the oxadiazole derivative represented by the general formula (1) include “Synthesis, 1986, # 5, p.411-413, Rekas”, “J. Org. Chem., 2009, 74 (16), pp6410-6413, Tomoya Mukai et al. "and the like.
The oxadiazole derivative represented by the general formula (2) is disclosed in documents such as “Tetrahedron Letters, 2014, vol. 55, # 13, p. It can be synthesized by the method.

(Synthesis example of ETM101)
The ETM101 uses 4- (3-Hydroxypropyl) benzonitrile as a starting material, protects the hydroxy group with a benzyl group, etc., converts the cyano group to a tetrazole group, and then couples this with 3-cyanobenzonitrile chloride. The cyano group of the obtained substance is converted to a tetrazole group in the same manner, and then this is coupled with 1-naphthoyl chloride, and further, a protecting group such as a benzyl group is deprotected by an operation such as hydrogenation. Can be synthesized.

(Synthesis example of ETM102)
In the ETM102, 10 parts by mass of biphenyl-4,4′-dicarboxylic acid dichloride and 13.9 parts by mass of 4- (benzoyloxy) benzohydrazide are reacted in anhydrous pyridine, the reaction mixture is poured into pure water, and the precipitate is filtered. The precipitate was washed with dilute hydrochloric acid and pure water, then recrystallized with a methanol / ethanol mixed solvent, and 15 parts by mass of the obtained needle-like crystals were refluxed in 812 parts by mass of phosphorus oxychloride, and then phosphorous oxychloride. Then, the reaction product is washed well with water and methanol. Subsequently, this is recrystallized with an ethanol / toluene mixed solvent. The obtained crystals are dissolved in ethyl acetate or an alcohol solvent, and a protecting group such as a benzyl group is deprotected and concentrated by an operation such as hydrogenation. It is dissolved in a nonpolar solvent such as toluene, and ethyl-5-chloro-5-oxopentanoate is added dropwise. ETM102 can be obtained by making it alkaline and hydrolyzing after completion | finish of reaction.

(Synthesis example of ETM201)
The ETM201 couples 4-methoxybenzohydride and 4-methyl-1-naphthaldehyde, and converts the methoxy group of the obtained substance into a phenol group by hydrogenation or alkali operation. It can be synthesized by dropping an equivalent amount of (4-chlorobutyl) triethoxysilane.

(Synthesis example of quinone derivatives represented by general formulas (3) and (4))
The quinone derivative represented by the general formula (3) can be synthesized according to “Archiv der Pharmazie, 1991, vol. 324, # 8 p. 491-495. Wurm et al.”.
The quinone derivative represented by the general formula (4) can be synthesized according to “Tetrahedron Letters, 1990, vol. 31, # 26, p. 3771 to 3774 Pandey et al.”.

(Synthesis example of fluorene derivative represented by the general formula (5))
(Synthesis example of ETM501)
The ETM501 was prepared by adding 100 parts by mass of ninhydrin and 118 parts by mass of benzyl ketone to ethanol, heating to reflux, and adding a methanol solution in which 9.5 parts by mass of potassium hydroxide was dissolved in the refluxed reaction solution. The mixture is added dropwise over a period of time, followed by stirring under reflux for 1 hour. The mixture is allowed to cool to precipitate crystals. The crystals are separated by filtration, washed with methanol, and recrystallized with acetonitrile. Put 130 parts by mass of the obtained crystals and 82.9 parts by mass of dimethyl acetylenedicarboxylate in a flask, set the external temperature to 160 ° C., heat the reaction solution, and heat for 2 hours after the internal temperature reaches 130 ° C. or higher. After stirring, the mixture is allowed to cool, the precipitated crystals are filtered off, and ethanol and toluene are added to the resulting crude crystals for recrystallization. 155 parts by mass of the obtained crystal and 45.7 parts by mass of malononitrile were added to THF, cooled at an external temperature of −10 ° C., and then 328 parts by mass of titanium tetrachloride dissolved in carbon tetrachloride at an internal temperature of 0 ° C. ± 5 ° C. 274 parts by mass of pyridine, slowly returned to room temperature, further heated to reflux, reacted at reflux for 8 hours, returned to room temperature, then purified water The reaction solution is added to the solution, toluene is further added, and the toluene layer is extracted by liquid separation. The toluene layer is washed with dilute hydrochloric acid, washed with water until the pH of the aqueous layer becomes neutral, and then subjected to vacuum distillation. The toluene layer is concentrated, and a toluene-ethanol mixed solution is added for recrystallization. The obtained crystals are separated by filtration and recrystallized again to obtain crystals. The obtained crystal is dissolved in an organic solvent such as toluene or THF to make it alkaline and hydrolyze. After completion of the reaction, pure water is added, the organic layer is extracted by liquid separation, the organic layer is concentrated by distillation under reduced pressure, dissolved in a nonpolar solvent such as toluene, and 2.5 equivalents of Ethyl 4-chlorobutyrate is added dropwise. To do. ETM501 can be obtained by making it alkaline and hydrolyzing after completion | finish of reaction.

(Synthesis example of tetracarboxylic acid diimide derivative represented by the general formula (6))
The tetracarboxylic acid diimide derivative represented by the general formula (6) can be synthesized, for example, by a method disclosed in a literature such as “Monatshefter Chemie, 1914, vol. 35”.
In general, tetracarboxylic dianhydride and an aniline derivative are reacted by heating and stirring in an aprotic polar solvent such as dimethylformamide, then recrystallized, and then purified by column chromatography or the like. It can be synthesized by drying. Further, for example, those in which the group p in the tetracarboxylic acid diimide derivative represented by the general formula (6) is a naphthalene ring are disclosed in JP-A No. 2001-265031 and “J. Am. Chem. Soc., 120323 ( 1) (1998) "," Journal of Organic Chemistry, 2007, vol. 72, # 19, p. 7287-7293 "and the like. Specifically, a naphthalene-1,4,5,8-tetracarboxylic dianhydride derivative, a 1,1-disubstituted hydrazine derivative, and a substituted amine derivative are simultaneously used in the presence or absence of a solvent. Or it can synthesize | combine by making it react sequentially.

(Synthesis example of ETM601)
The ETM601 was prepared by heating 300 parts by mass of pyromellitic dianhydride, 260 parts by mass of 2- (trifluoromethyl) aniline, and 300 parts by mass of methyl 4- (4-aminophenyl) butanoate in dimethylformamide under reflux for 3 hours. After cooling, the reaction mixture is filtered and the precipitate is washed with dimethylformamide, further washed with ether and dried, and the resulting product is purified. Furthermore, it can synthesize | combine by hydrolyzing and dropping (3-chloropropyl) trimethoxysilane by an equivalent amount.

(Synthesis example of ETM602)
The compound represented by ETM602 uses 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride instead of pyromellitic dianhydride in the synthesis process of ETM601, and 2- (trifluoro Instead of 260 parts by weight of methyl) aniline, 180 parts by weight of 2,6-dimethylaniline was used, and instead of 300 parts by weight of methyl 4- (4-aminophenyl) butanoate, 210 parts by weight of 4- (benzyloxy) -2,6-dimethylylline And (4-chlorobutyl) triethoxysilane can be synthesized by the same method except that (4-chlorobutyl) triethoxysilane is used instead of (3-chloropropyl) trimethoxysilane.

(Synthesis example of ETM603)
The ETM603 uses naphthalene-1,4,5,8-tetracarboxylic dianhydride instead of pyromellitic dianhydride in the synthesis step of the ETM601, and 260 parts by mass of 2- (trifluoromethyl) aniline. 1,2-dimethylpropylamine 160 parts by weight instead of methyl 4- (4-aminophenyl) butanoate 300 parts by weight 2- (4-Aminocyclohexyl) ethanol 180 parts by weight Except for the above, it can be synthesized by the same method. In addition, the hydrolysis and dripping of the silylating agent performed in the synthesis step of the compound represented by ETM601 are not performed.

(Synthesis example of ETM604)
The ETM604 uses naphthalene-1,4,5,8-tetracarboxylic dianhydride instead of pyromellitic dianhydride in the synthesis process of the ETM601, and 260 parts by mass of 2- (trifluoromethyl) aniline. Instead of 300 parts by weight of methyl 4- (4-aminophenyl) butanoate, 180 parts by weight of 4- (benzyloxy) -2,6-dimethylylline, instead of 300 parts by weight of methyl 4- (4-aminophenyl) butanoate, It can be synthesized by the same method except that (4-chlorobutyl) triethoxysilane is used instead of trimethoxysilane.

(Synthesis example of ETM605)
The ETM605 uses perylene-3,4,9,10-tetracarboxylic dianhydride instead of pyromellitic dianhydride in the synthesis process of ETM601, and 260 parts by mass of 2- (trifluoromethyl) aniline. Can be synthesized by the same method except that 180 parts by mass of 2,5-di-tert-butylanline and 200 parts by mass instead of 300 parts by mass of methyl 4- (4-aminophenyl) butanoate. it can.

(Synthesis example of silole derivatives represented by general formulas (7) to (9))
Examples of the silole derivatives represented by the general formula (7) to the general formula (9) include (a) Science 1998, 282, pages 913 to 915, and (b) J. Org. Org. Chem. , 2002, VOL. 67, 9392-9396, (c) J. MoI. Org. Chem. , 2006, VOL. 71, pages 7826-7834, (d) J. MoI. Am. Chem. Soc. , VOL. 124, no. 1, 2002, pages 49-57, (e) WO 2006/002731, page 15, (f) J. Am. C. S. [Section] B, Physical Organic 1996, pages 733-735, (g) Chem. Lett. , 1982, p. 1195 to p. 1198 and the like.

(Synthesis example of ETM701)
The ETM 701 can be synthesized according to “Chemistry-A European Journal, 2000, vol. 6, # 9 p. 1683-1692, Yamaguchi, Shigehiro et al.”.

(Synthesis example of ETM801)
The ETM801 was prepared by dissolving 23.4 parts by mass of 3- (2-bromophenyl) pyridine synthesized in accordance with the method disclosed in JP2013-20996A and accumulating 113.4 parts by mass of 30% hydrogen peroxide. The mixture was heated and stirred at 95 ° C. for 5 hours, the reaction solution was concentrated about 90% under reduced pressure, 1% aqueous sodium bicarbonate was added to the residue, the organic layer was extracted with ethyl acetate, and the organic layer was extracted three times with saturated brine. After washing, the organic layer was concentrated under reduced pressure, chloroform was added to the residue, 43.0 parts by mass of phosphorus oxybromide was added, the mixture was refluxed for 3 hours, and the solvent and excess phosphorus oxybromide were distilled off under reduced pressure. The residue is recrystallized from toluene. 25.0 parts by mass of the obtained crystals were dissolved in dehydrated ether, the internal temperature was cooled to −75 ° C., and then 75.1 parts by mass of 1.6M n-butyllithium / hexane solution was added to an internal temperature of −70 ° C. Then, the mixture was stirred at the same temperature for 2 hours, and then a solution prepared by dissolving 21.2 parts by mass of dichlorodiphenylsilane in dehydrated ether was slowly added while maintaining the internal temperature at -65 ° C or lower. After stirring at the same temperature for 3 hours, the reaction was allowed to warm to room temperature, followed by further stirring for 2 hours. After completion of the reaction, the solvent is distilled off under reduced pressure, and the residue is recrystallized with a mixed solvent of methylene chloride ethanol. 20.0 parts by mass of the obtained crystals are dissolved in acetic acid, 67.6 parts by mass of 30% hydrogen peroxide are added, and the mixture is heated and stirred at 95 ° C. for 5 hours. 1% aqueous sodium bicarbonate was added, the organic layer was extracted with ethyl acetate, the organic layer was washed three times with saturated brine, the organic layer was concentrated under reduced pressure, chloroform was added to the residue, and phosphorus oxybromide 25. 6 parts by mass is added, heating under reflux is carried out for 3 hours, the solvent and excess phosphorus oxybromide are distilled off under reduced pressure, and the residue is recrystallized with toluene. 23.0 parts by mass of the obtained crystals were dissolved in dimethylacetamide (DMAc), and the carboxyl group was protected with an alcohol, 34.1 parts by mass of ethyl carbazol-3-carboxylate, 23.3 parts by mass of copper iodide, potassium carbonate 16.9 parts by mass and 1.3 parts by mass of L-proline were added, and the mixture was stirred with heating at an internal temperature of 150 ° C. for 6 hours under a nitrogen stream. After completion of the reaction, the solvent was distilled off under reduced pressure, and the residue was subjected to silica gel column chromatography. Purify by chromatography (developing solvent = heptane: methylene chloride = 9: 1). Further, it is dissolved in an organic solvent such as toluene or THF, and made alkaline and hydrolyzed. After completion of the reaction, pure water is added, the organic layer is extracted by liquid separation, the organic layer is concentrated by distillation under reduced pressure, dissolved in a nonpolar solvent such as toluene, and 1.5 equivalents of Ethyl 4-chlorobutyrate is added dropwise. To do. After completion of the reaction, the ETM801 can be synthesized by making it alkaline and hydrolyzing.

(Synthesis of ETM901)
The ETM901 can be synthesized according to the method disclosed as Synthesis Example 7 in JP2013-20996A.

The average primary particle size of the surface-modified metal oxide particles or the non-surface-modified metal oxide particles is preferably in the range of 5 to 200 nm from the viewpoint of electron transport properties and dispersibility, and in the range of 10 to 100 nm. More preferably, it is within.
Further, the average primary particle size of the surface-modified metal oxide particles or the non-surface-modified metal oxide particles is within a range of 10 to 50 nm, and the surface-modified metal oxide particles and the non-surface-modified metal oxide It is preferable that the particle size of the object particles is different from that of improving the hiding power on the conductive support, suppressing moire and interference fringes, and eliminating pinholes that cause abnormal images.

The number average primary particle size of the surface-modified metal oxide particles or the non-surface-modified metal oxide particles is taken by a scanning electron microscope “JSM-7500F” (manufactured by JEOL Ltd.) and is magnified 100,000 times. For a photographic image (excluding aggregated particles) captured by a scanner, using an automatic image processing analyzer “LUZEX (registered trademark) AP (software version Ver. 1.32)” (manufactured by Nireco), A binarization treatment is performed on the surface-modified metal oxide particles or the non-surface-modified metal oxide particles, and a horizontal ferret diameter for any 100 of the surface-modified metal oxide particles or the non-surface-modified metal oxide particles. And the average value was defined as the number average primary particle size.
Here, the horizontal ferret diameter refers to the length of the side parallel to the x axis of the circumscribed rectangle when the image of the surface modified metal oxide particles or the non-surface modified metal oxide particles is binarized.

In addition, it is preferable that the surface-modified metal oxide particles are unevenly distributed on the charge generation layer side, because unintentional movement of negative charges generated by thermal excitation generated in the charge generation layer can be easily prevented.
Here, in the present invention, “unevenly distributed” means surface-modified metal oxide particles or non-surface when the cross section of the intermediate layer is observed and the thickness of the intermediate layer is equally divided into three layers from the surface side. A state in which the ratio of the modified metal oxide particles is 1.5 times or more of the average ratio of the ratio of the surface modified metal oxide particles or the non-surface modified metal oxide particles to the entire intermediate layer Say. That is, the surface-modified metal oxide particles or the non-surface-modified metal oxide particles are the entire surface-modified metal oxide particles or the whole non-surface-modified metal oxide particles in any one of the three divided layers. The state where 50% or more of is included. In other words, the surface-modified metal oxide particles or the non-surface-modified metal oxide particles having a high-concentration portion are present in a layered manner in the intermediate layer. It can detect by cross-sectional observation by SEM etc. Further, the distinction between surface-modified metal oxide particles and non-surface-modified metal oxide particles can be confirmed by a difference in particle diameter by cross-sectional observation, element mapping by ESCA measurement, and round slice observation by ICP.

[Middle layer]
The intermediate layer according to the present invention has a function of transporting electrons generated in the photosensitive layer to the conductive support (electron transport function) and a function of preventing injection of holes from the conductive support to the photosensitive layer (blocking function). ) And provides an adhesive function between the conductive support and the organic photosensitive layer.

<Binder resin for intermediate layer>
The intermediate layer according to the present invention contains the surface-modified metal oxide particles and the non-surface-modified metal oxide particles according to the present invention in a binder resin (hereinafter also referred to as “binder resin for intermediate layer”). Is.
Examples of the intermediate layer binder resin include thermoplastic resins, thermosetting resins, and photocurable resins. The intermediate layer according to the present invention is preferably a curable resin layer made of a thermosetting resin or a photocurable resin. In particular, the photocurable resin layer is used for suppressing deterioration of organic molecules or for a charge generation layer. This is preferable in terms of suppressing contamination of the coating solution.

Examples of the thermoplastic resin include vinyl resins such as polyacrylic resins and styrene / butadiene copolymer resins, and condensation resins such as polyamide resins, polyester resins, polycarbonate resins, urethane elastomer resins, and polyamide-silicone resins. Can be mentioned.
As said thermosetting resin, a phenol resin, an epoxy resin, a melamine resin, an unsaturated polyester resin, a polyimide resin etc. can be used preferably, for example. Specific examples of the thermosetting resin preferably used in the present invention include the following.
Phenol resin: Priorofen J-325 (manufactured by DIC)
Epoxy resin: U-33 (Amicon Japan)
Melamine resin: Super Becamine L-121 (manufactured by DIC)
Unsaturated polyester resin: Barnock D-160 (manufactured by Nippon Reich)
Polyimide resin: Kerimide 501 (Mitsui Petrochemical Co., Ltd.)

The polymerizable compound constituting the photocurable resin is a resin that is polymerized (cured) by irradiation with active rays such as ultraviolet rays, electron beams, and visible rays, and is generally used as a binder resin for photoconductors such as polystyrene and polyacrylate. Is preferred. In particular, a resin that cures when irradiated with visible light having a wavelength of 400 nm or more can suppress deterioration of the electron transporting compound and a decrease in sensitivity of the charge generation layer, prevent occurrence of image memory, This is preferable in that it is effective in preventing the occurrence of image defects such as spots and fog.
The polymerizable compound according to the present invention is preferably a crosslinkable polymerizable compound from the viewpoint of maintaining high durability.
Specific examples of the crosslinkable polymerizable compound include polymerizable compounds having two or more radical polymerizable functional groups (hereinafter also referred to as “polyfunctional radical polymerizable compounds”).

As the crosslinkable polymerizable compound, a compound having one radical polymerizable functional group (hereinafter also referred to as “monofunctional radical polymerizable compound”) can be used in combination with the polyfunctional radical polymerizable compound. In the case of using a monofunctional radically polymerizable compound, the proportion is preferably 20% by mass or less based on the total amount of monomers for forming the binder resin.
Examples of the radical polymerizable functional group include a vinyl group, an acryloyl group, and a methacryloyl group.
Since the polyfunctional radical polymerizable compound can be cured in a small amount of light or in a short time, an acryloyl group (CH ₂ ═CHCO—) or a methacryloyl group (CH ₂ ═CCH ₃ CO—) is used as the radical polymerizable functional group. ) Is particularly preferably an acrylic monomer having 2 or more) or oligomers thereof. Accordingly, the resin is preferably an acrylic resin formed from an acrylic monomer or an oligomer thereof.
In the present invention, the polyfunctional radically polymerizable compound may be used alone or in combination. In addition, these polyfunctional radical polymerizable compounds may use monomers, but may be used after oligomerization.

Hereinafter, specific examples of the polyfunctional radically polymerizable compound are shown.
In chemical formulas showing the following exemplary compounds M1 to M15, R represents an acryloyl group (CH ₂ ═CHCO—), and R ′ represents a methacryloyl group (CH ₂ ═CCH ₃ CO—).

<Polymerization initiator>
The intermediate layer according to the present invention is either a compound having a structure (phenylphosphine oxide structure) represented by the following general formula (Int), a compound containing a phosphorus element other than the compound, or a compound containing a sulfur element It is preferable to contain 0.01 ppm or more of the compound derived from 1 by mass.
That is, a reaction when a compound having a structure represented by the general formula (Int), a compound containing a phosphorus element other than the compound, or a compound containing a sulfur element is used as the polymerization initiator for the intermediate layer. It means that 0.01 ppm or more of products and unreacted substances are contained.
For example, XPS measurement (X-ray photoelectron spectroscopy measurement) can be used as a method for measuring the reaction product and the unreacted product. Specifically, K-Alpha made by Thermo Fisher Scientific is used as the XPS measurement device, and measurement is performed using Al monochromatic X-ray as the X-ray source, acceleration voltage is set to 7 kV, and emission current is set to 6 mV. It implements and measures about the element (phosphorus element, sulfur element) to measure.

[In the above general formula (Int), R ₁₀₁ and R ₁₀₂ each independently have a hydrogen atom, a C 1-6 alkyl group which may have a substituent, or a substituent. The group selected from the group which consists of a C3-C6 cycloalkyl group, the aryl group which may have a substituent, a hydroxy group, and a carbonyl group is represented. R ₁₀₁ and R ₁₀₂ may be the same or different. ]

  Examples of the compound having a structure represented by the general formula (Int) include the following exemplified compounds.

  Of the two Irgacure TPO (IrgTPO) and Irgacure 819 (Irg819), Irgacure 819 is preferred.

  The polymerization initiator containing the elemental sulfur is preferably an O-acyl oxime having a structure represented by the following general formula (B).

In general formula (B), R ₁ and R ₂ are each independently a hydrogen atom, an optionally substituted alkyl group having 1 to 6 carbon atoms, or an optionally substituted carbon number. It is a group selected from the group consisting of 3 to 6 cycloalkyl groups and optionally substituted aryl groups.
R ₃ may have a hydrogen atom, an optionally substituted alkyl group having 1 to 6 carbon atoms, an optionally substituted alkoxy group having 1 to 6 carbon atoms, or a substituent. It is a group selected from the group consisting of a good aryl group, a halogen atom, a cyano group, a nitro group and a hydroxy group, and an optionally substituted carbonyl group.

Specific examples of the compound having the structure represented by the general formula (B) are shown below.

Examples of the compound containing a phosphorus element other than the compound having the structure represented by the general formula (Int) include a photopolymerization initiator of the formula I described in JP-T-2017-522364. Can do.
Moreover, in this invention, it is preferable to contain 2 types, an acyl phosphine oxide and O-acyl oxime, 3 or more types may be used and each polymerization initiator may be used independently.

Moreover, as a polymerization initiator, a photoinitiator may be sufficient and any of a thermal polymerization initiator can be used.
The addition ratio of the polymerization initiator is preferably in the range of 0.1 to 20 parts by mass, more preferably in the range of 0.5 to 10 parts by mass with respect to 100 parts by mass of the polymerizable compound.

  In addition, as a commercial item of the polymerization initiator of the O-acyloxime, for example, Irgacure OXE01 of Exemplified Compound B-1 and Irgacure OXE02 of Exemplified Compound B-40 (both manufactured by BASF Japan Ltd.) Examples thereof include PBG-305 and PBG-329 (both manufactured by Changzhou Strong Electronic New Materials Co., Ltd.), which are O-acyloxime initiators having a disulfide structure.

Examples of the solvent for forming the intermediate layer include butylamine, nibrenediamine, N, N-dimethylboramide, acetone, methylethylketone, cyclohexanone, tetrahydrofuran, di3xan, ethyl acetate, butyl acetate, toluene, xylene. Acetophenone, chloroform, dichloromethane, dichloroethane, trichloroethane and the like.
The intermediate layer has functions such as adhesion to a charge generation layer provided thereon and adjustment of the image quality of an image formed on the photoreceptor, and retains the charge applied on the photoreceptor. It also has the function. In addition, it is also required not to inhibit the movement of one of the carriers generated during exposure to the ground (support side). Therefore, the thickness of the intermediate layer provided on the conductive support is preferably 10 μm or less. Preferably it exists in the range of 0.1-4 micrometers.

[Conductive support]
The conductive support is a member that supports the intermediate layer, the photosensitive layer and the protective layer and has conductivity.
Examples of conductive supports include a metal drum or sheet, a plastic film having a laminated metal foil, a plastic film having a deposited layer of conductive material, a conductive material or conductive material, and A metal member, a plastic film, or paper having a conductive layer formed by applying a paint made of a binder resin is included.
Examples of metals include aluminum, copper, chromium, nickel, zinc and stainless steel.
Examples of the conductive material include the metal, indium oxide, and tin oxide. From the viewpoint of processability, fastness, and lightness, the metal is preferably aluminum.

[Photosensitive layer]
The photosensitive layer is a layer for forming an electrostatic latent image corresponding to an intended image on the surface of the photoreceptor by exposure described later.
The photosensitive layer can be composed of, for example, a laminate of a charge generation layer containing a binder resin for a charge generation layer and a charge generation material, and a charge transport layer containing a binder resin for the charge transport layer and a charge transport material. .

[Charge generation layer]
As the binder resin for the charge generation layer, a known resin used as the binder resin for the charge generation layer can be used.
Examples of the binder resin for the charge generation layer include a formal resin, a butyral resin, a silicone resin, a silicone-modified butyral resin, and a phenoxy resin. The binder resin for the charge generation layer may be one kind or more.

  Examples of charge generation materials include azo raw materials such as Sudan Red and Diane Blue; quinone compounds such as pyrenequinone and anthanthrone; quinocyanine compounds; perylene compounds; indigo compounds such as indigo and thioindigo; Compounds; and phthalocyanine compounds. The charge generation material may be one kind or more.

The phthalocyanine compound may or may not have a central metal. Examples of the central metal include Ti, Fe, V, Si, Pb, Al, Zn, and Mg. The central metal may be one kind or more. From the viewpoint of increasing the sensitivity of the charge generation layer, the phthalocyanine compound is preferably a titanyl phthalocyanine compound having Ti as a central metal.
From the above viewpoint, the titanyl phthalocyanine compound has a maximum peak at a Bragg angle (2θ ± 0.2) of 27.3 ° in X-ray diffraction using CuKα rays, and is 7.4 °, 9.7 °, and Y-type titanyl phthalocyanine compound having a clear diffraction peak at 24.2 °, or 2,3- having clear diffraction peaks at Bragg angles of 8.3 °, 24.7 °, 25.1 ° and 26.5 ° A butanediol adduct titanyl phthalocyanine is preferred.

  The content of the charge generation material is preferably in the range of 20 to 600 parts by mass, more preferably in the range of 50 to 500 parts by mass with respect to 100 parts by mass of the binder resin for the charge generation layer. If the content of the charge generation material is within the above range, the dispersibility of the charge generation material can be improved and the electric resistance of the charge generation layer can be reduced. As a result, an increase in residual charge accompanying use of the photoreceptor is further suppressed.

  For example, the thickness of the charge generation layer is preferably in the range of 0.01 to 2 μm, and more preferably in the range of 0.15 to 1.5 μm. The thickness of the charge generation layer can be appropriately adjusted according to the type of the binder resin for the charge generation layer and the type and content of the charge generation material.

[Charge transport layer]
As the binder resin for the charge transport layer, a known resin used as the binder resin for the charge transport layer can be used. Examples of the binder resin for the charge transport layer include polystyrene resin, acrylic resin, methacrylic resin, vinyl chloride resin, vinyl acetate resin, polyvinyl butyral resin, epoxy resin, polyurethane resin, phenol resin, polyester resin, alkyd resin, polycarbonate resin. , Silicone resins, melamine resins, insulating resins such as copolymer resins having two or more of the repeating units of these resins; and organic semiconductors such as poly-N-vinylcarbazole. From the viewpoint of enhancing the dispersibility of the charge generating material and enhancing the characteristics of the photoreceptor, the binder resin for the charge transport layer is preferably a polycarbonate resin. The binder resin for the charge transport layer may be one kind or more.

  Examples of charge transport materials include triphenylamine derivatives, hydrazone compounds, styryl compounds, benzidine compounds and butadiene compounds. One or more charge transport materials may be used.

  The content of the charge transport material is preferably in the range of 10 to 200 parts by mass with respect to 100 parts by mass of the binder resin for the charge transport layer.

  The thickness of the charge transport layer is preferably in the range of 10 to 40 μm. The thickness of the charge transport layer is more preferably in the range of 10 to 20 μm from the viewpoint of increasing the internal electric field of the photoreceptor and suppressing an increase in residual charge associated with the use of the photoreceptor. The thickness of the charge transport layer can be appropriately adjusted according to the type of binder resin for the charge transport layer and the type and content of the charge transport material.

  The charge transport layer may contain other components as necessary. Examples of the other components include an antioxidant, an electronic conductive agent, a stabilizer, and silicone oil.

The photosensitive layer according to the present invention may be composed of a single layer. In this case, the photosensitive layer can be composed of, for example, a single layer containing the binder resin for the photosensitive layer, the charge transport material, and the charge generation material.
The thickness of the photosensitive layer is preferably in the range of 10 to 50 μm, and more preferably in the range of 20 to 40 μm.

  When the photosensitive layer is composed of a single layer, examples of the binder resin for the photosensitive layer include polystyrene resin, polyethylene resin, polypropylene resin, acrylic resin, methacrylic resin, vinyl chloride resin, vinyl acetate resin, and polyvinyl butyral resin. , Epoxy resin, polyurethane resin, phenol resin, polyester resin, alkyd resin, polycarbonate resin, silicone resin, melamine resin, copolymer resin containing two or more of these resins (for example, vinyl chloride-vinyl acetate copolymer resin) , Vinyl chloride-vinyl acetate-maleic anhydride copolymer resin), poly-vinyl carbazole resin, polyacrylate resin, styrene-acrylonitrile copolymer resin, polymethacrylic ester resin, and styrene-methacrylic ester copolymer Resin, including That.

[Protective layer]
The protective layer is a layer for protecting the photosensitive layer.
The protective layer is disposed on the photosensitive layer and constitutes the surface of the photoreceptor. The protective layer includes, for example, a binder resin for the protective layer, metal oxide particles for the protective layer, and a charge transport material for the protective layer.

  As the binder resin for the protective layer, a known resin used as the binder resin for the protective layer can be used. Examples of the binder resin for the protective layer include polyvinyl butyral resin, epoxy resin, polyurethane resin, phenol resin, polyester resin, alkyd resin, polycarbonate resin, silicone resin, acrylic resin, melamine resin, and vinyl chloride-vinyl acetate copolymer. Is included. The binder resin for the protective layer may be one kind or more.

  From the viewpoint of durability of the photoreceptor, the binder resin for the protective layer is preferably a polymerization cured product of a radical polymerizable composition containing a radical polymerizable monomer. In this case, the radically polymerizable composition may further contain metal oxide particles for the protective layer and a charge transport material for the protective layer.

  The radical polymerizable monomer has two or more radical polymerizable functional groups. The radical polymerizable functional group is preferably a (meth) acryloyl group. Examples of the radical polymerizable monomer having a (meth) acryloyl group include the compounds represented by the formulas M1 to M15 described for the intermediate layer binder resin.

  From the viewpoint of improving the image quality stability by appropriately adjusting the electrical resistance of the protective layer and increasing the strength of the protective layer, the protective layer preferably includes metal oxide particles for the protective layer.

  Examples of metal oxides constituting the metal oxide particles for the protective layer include titanium oxide, zinc oxide, alumina (aluminum oxide), silica (silicon oxide), tin oxide, antimony oxide, indium oxide, bismuth oxide, oxidation Magnesium, lead oxide, tantalum oxide, yttrium oxide, cobalt oxide, copper oxide, manganese oxide, selenium oxide, iron oxide, zirconium oxide, germanium oxide, niobium oxide, molybdenum oxide, vanadium oxide, tin-doped indium oxide, antimony Are doped with tin oxide and zirconium oxide. The metal oxide particles for the protective layer may be one kind or more. When there are two or more kinds of metal oxide particles for the protective layer, the metal oxide particles may be a solid solution or a fusion product.

  For example, the number average primary particle size of the metal oxide particles for the protective layer is preferably in the range of 1 to 300 nm, and more preferably in the range of 3 to 100 nm. The number average primary particle size of the metal oxide particles for the protective layer can be measured by the same method as the number average primary particle size of the metal oxide particles for the intermediate layer.

  The content of the metal oxide particles for the protective layer is, for example, preferably in the range of 5 to 100 parts by volume with respect to 100 parts by volume of the binder resin in the protective layer, and in the range of 15 to 30 parts by volume. More preferably. It is preferable that the content of the metal oxide particles for the protective layer is within the above range from the viewpoint of improving the strength, image quality stability, and film formability of the protective layer.

From the viewpoint of improving the dispersibility of the metal oxide particles for the protective layer, the metal oxide particles for the protective layer are preferably surface-treated with a surface treatment agent. From the viewpoint of further increasing the strength of the protective layer, the surface treatment agent preferably has a reactive functional group capable of reacting with the radical polymerizable monomer. The reactive functional group is preferably a radical reactive functional group.
The radical reactive functional group is preferably a (meth) acryloyl group.
Examples of the surface treatment agent include a silane coupling agent, a titanium coupling agent, an inorganic oxide, a fluorine-modified silicone oil, a fluorine-based surfactant, and a fluorine-based graft polymer. The surface treatment agent may be one kind or more.

  The surface treatment agent is preferably a silane coupling agent having a (meth) acryloyl group. Examples of the silane coupling agent having a (meth) acryloyl group include compounds represented by the following formulas S-1 to S-34.

_{S-1: CH 2 = CHSi} (CH 3) (OCH 3) 2
_{S-2: CH 2 = CHSi} (OCH 3) 3
S-3: CH ₂ = CHSiCl _{3
S-4: CH 2 = CHCOO} (CH 2) 2 Si (CH 3) (OCH 3) 2
_{S-5: CH 2 = CHCOO} (CH 2) 2 Si (OCH 3) 3
_{S-6: CH 2 = CHCOO} (CH 2) 2 Si (OC 2 H 5) (OCH 3) 2
_{S-7: CH 2 = CHCOO} (CH 2) 3 Si (OCH 3) 3
_{S-8: CH 2 = CHCOO} (CH 2) 2 Si (CH 3) Cl 2
_{S-9: CH 2 = CHCOO} (CH 2) 2 SiCl 3
_{S-10: CH 2 = CHCOO} (CH 2) 3 Si (CH 3) Cl 2
S-11: CH ₂ = CHCOO (CH ₂ ) ₃ SiCl _{3
S-12: CH 2 = C} (CH 3) COO (CH 2) 2 Si (CH 3) (OCH 3) 2
_{S-13: CH 2 = C} (CH 3) COO (CH 2) 2 Si (OCH 3) 3
_{S-14: CH 2 = C} (CH 3) COO (CH 2) 3 Si (CH 3) (OCH 3) 2
_{S-15: CH 2 = C} (CH 3) COO (CH 2) 3 Si (OCH 3) 3
_{S-16: CH 2 = C} (CH 3) COO (CH 2) 2 Si (CH 3) Cl 2
_{S-17: CH 2 = C} (CH 3) COO (CH 2) 2 SiCl 3
_{S-18: CH 2 = C} (CH 3) COO (CH 2) 3 Si (CH 3) Cl 2
_{S-19: CH 2 = C} (CH 3) COO (CH 2) 3 SiCl 3
_{S-20: CH 2 = CHSi} (C 2 H 5) (OCH 3) 2
_{S-21: CH 2 = C} (CH 3) Si (OCH 3) 3
_{S-22: CH 2 = C} (CH 3) Si (OC 2 H 5) 3
_{S-23: CH 2 = CHSi} (OCH 3) 3
_{S-24: CH 2 = C} (CH 3) Si (CH 3) (OCH 3) 2
_{S-25: CH 2 = CHSi} (CH 3) Cl 2
_{S-26: CH 2 = CHCOOSi} (OCH 3) 3
_{S-27: CH 2 = CHCOOSi} (OC 2 H 5) 3
_{S-28: CH 2 = C} (CH 3) COOSi (OCH 3) 3
_{S-29: CH 2 = C} (CH 3) COOSi (OC 2 H 5) 3
_{S-30: CH 2 = C} (CH 3) COO (CH 2) 3 Si (OC 2 H 5) 3

It is preferable that the processing amount of the surface treating agent with respect to the metal oxide particles for the protective layer is, for example, in the range of 0.1 to 100 parts by mass with respect to 100 parts by mass of the metal oxide particles for the protective layer.
The amount of the treatment can be appropriately adjusted according to the number average primary particle size of the metal oxide particles for the protective layer and the type of the surface treatment agent.

  When the surface of the metal oxide particles for the protective layer is surface-treated with the surface treatment agent, the component after the reaction of the surface treatment agent is supported on the surface of the metal oxide particles in the protective layer. Has been. The surface treatment of the metal oxide particles for the protective layer can be performed by a known method.

The protective layer preferably contains a charge transport material for the protective layer from the viewpoint of further suppressing the generation of image memory.
The charge transport material for the protective layer is a compound that imparts charge transport capability to the protective layer. The charge transport material for the protective layer is only required to exhibit the function, and can be appropriately selected from known compounds. For example, when the protective layer is composed of a polymerized and cured film of the above radical polymerizable composition by ultraviolet rays, the charge transport material for the protective layer has little absorption with respect to ultraviolet rays or does not absorb ultraviolet rays. A compound is preferred.
The charge transport material for the protective layer is preferably a compound represented by the following general formula (CTM).

In the above general formula (CTM), R ₁ , R ₂ , R ₃ and R ₄ each independently represent a hydrogen atom, an alkyl group having 1 to 7 carbon atoms, or an alkoxy group having 1 to 7 carbon atoms. To express.
k, p, and n represent the integer of 1-5, and m represents the integer of 1-4. When k, p, m and n are 2 or more, the plurality of groups may be the same as or different from each other.

  Examples of the charge transport material represented by the general formula (CTM) include compounds represented by the following formulas CTM-1 to CTM-22.

The content of the charge transport material for the protective layer is, for example, in the range of 20 to 100 parts by mass and in the range of 40 to 70 parts by mass with respect to 100 parts by mass of the binder resin for the protective layer. Is more preferable.
It is preferable that the content of the charge transport material for the protective layer is 20 parts by mass or more from the viewpoint of obtaining desired electrical characteristics and suppressing the occurrence of image memory. The content of the charge transport material for the protective layer is preferably 100 parts by mass or less from the viewpoint of obtaining desired film strength. The content of the charge transport material for the protective layer can be appropriately adjusted according to the intended film strength and electrical characteristics of the protective layer.

  The protective layer may contain other components as necessary. Examples of such other components include lubricant particles and antioxidants.

Examples of the lubricant particles include fluororesin particles. Examples of the fluororesin constituting the fluororesin particle include tetrafluoroethylene resin, trifluoroethylene chloride resin, hexafluorochloroethylene propylene resin, vinyl fluoride resin, vinylidene fluoride resin, difluoride dichloride. Ethylene resins and copolymers thereof are included.
The fluororesin is preferably a tetrafluoroethylene resin or a vinylidene fluoride resin. The lubricant particles may be one kind or more.

  The number average primary average particle diameter of the lubricant particles is preferably in the range of 0.01 to 1 μm, and more preferably in the range of 0.05 to 0.5 μm.

  The content of the lubricant particles is preferably contained at a ratio in the range of 5 to 70 parts by mass with respect to 100 parts by mass of the binder resin for the protective layer, and more preferably in the range of 10 to 60 parts by mass. preferable.

  For example, the thickness of the protective layer is preferably in the range of 0.2 to 10 μm, and more preferably in the range of 0.5 to 6 μm.

[Method for producing photoreceptor]
The method for producing an electrophotographic photosensitive member of the present invention is characterized in that the step of forming the intermediate layer includes a visible light curing step of curing with light having a wavelength of 400 nm or more.
Specifically, (A) a step of forming surface-modified metal oxide particles and non-surface-modified metal oxide particles, and (B) conductive using the surface-modified metal oxide particles and non-surface-modified metal oxide particles. A step of forming an intermediate layer on the conductive support, (C) a step of forming a photosensitive layer on the intermediate layer, and (D) a step of forming a protective layer on the photosensitive layer.

(A) Step of forming surface-modified metal oxide particles and non-surface-modified metal oxide particles The surface-modified metal oxide particles are formed by surface-modifying the metal oxide particles with the electron transporting compound. Can do.
Specifically, metal oxide particles containing any element of tin, titanium, and zinc, an electron transporting compound, and an organic solvent are stirred and mixed, then dispersed at a predetermined temperature, and the organic solvent is separated and removed by distillation under reduced pressure. And the surface modification by an electron transport compound can be performed by heating the obtained dried material.

(B) Step of forming the intermediate layer For example, the intermediate layer is obtained by dissolving or dispersing the binder resin for the intermediate layer in a solvent, and then homogenizing the surface-modified metal oxide particles and the non-surface-modified metal oxide particles according to the present invention. A dispersion liquid is obtained by dispersing the dispersion liquid, and the dispersion liquid is allowed to stand, followed by filtration to prepare a coating liquid for forming an intermediate layer. The coating liquid for forming an intermediate layer is applied to the surface of the conductive support to form a coating film. Can be formed by curing the coating film.

The solvent used for the formation of the intermediate layer is one that can dissolve the binder resin for the intermediate layer and can obtain good dispersibility of the surface-modified metal oxide particles and the non-surface-modified metal oxide particles. That's fine.
In order to improve the storage stability and the dispersibility of the surface-modified metal oxide particles and the non-surface-modified metal oxide particles, a co-solvent may be used in combination.
Examples of the cosolvent include benzyl alcohol, toluene, cyclohexanone, and tetrahydrofuran.

  As a means for dispersing the surface-modified metal oxide particles and the non-surface-modified metal oxide particles, an ultrasonic disperser, a bead mill, a ball mill, a sand mill, a homomixer, or the like can be used.

  Although the density | concentration of the binder resin for intermediate | middle layers in the coating liquid for intermediate | middle layer formation changes also with the layer thickness and coating method of an intermediate | middle layer, the usage-amount of the solvent with respect to 100 mass parts of binder resins for intermediate | middle layers is 100-3000 mass parts, for example. It is preferably within the range, more preferably within the range of 500 to 2000 parts by mass.

The method for applying the intermediate layer forming coating solution is not particularly limited, and examples thereof include a dip coating method, a spray coating method, a spinner coating method, a bead coating method, a blade coating method, a beam coating method, and a slide hopper method. .
Examples of the method for curing the coating film of the coating liquid for forming the intermediate layer include irradiation of actinic rays to the coating film and heating of the coating film.
Irradiation of the actinic ray to the coating film can be performed under known conditions for forming an intermediate layer by radical reaction of a radical reactive component, for example. In particular, in the present invention, the coating film is preferably cured by irradiation with visible light having a wavelength of 400 nm or more.

The irradiation energy, irradiation time, and the like of actinic rays can be appropriately set according to the type of light source used, the output of the light source, the type of radical reactive functional group for forming the protective layer, and the like. Irradiation energy of active rays is preferably in the range of 5~500mJ / cm ^2, and more preferably in a range of 5 to 100 mJ / cm ^2. Moreover, it is preferable that irradiation time is 0.1 second-10 minutes, and it is more preferable that it is 0.1 second-5 minutes.

  Examples of types of actinic light sources include low pressure mercury lamps, medium pressure mercury lamps, ultra high pressure mercury lamps, carbon arc lamps, metal halide lamps, xenon lamps, flash (pulse) xenon, and ultraviolet LEDs. The output of the active light source is preferably in the range of 0.1 to 5 kW, and more preferably in the range of 0.5 to 3 kW. Examples of the types of actinic rays include visible light, ultraviolet rays, electron beams, X-rays, and gamma rays. The wavelength of the active light is preferably visible light of 400 nm or more.

The thickness of the intermediate layer is preferably in the range of 0.5 to 5 μm.
If the thickness of the intermediate layer is 0.5 μm or more, the entire surface of the conductive support can be sufficiently covered, so that the injection of holes from the conductive support can be sufficiently blocked, As a result, the occurrence of image defects such as black spots and fog can be further suppressed. On the other hand, if the thickness of the intermediate layer is 5 μm or less, the electrical resistance can be made appropriate and sufficient electron transport properties can be obtained, and as a result, the occurrence of density unevenness can be further suppressed.

(C) Step of forming photosensitive layer The step of forming the photosensitive layer includes a step of forming a charge generation layer on the intermediate layer and a step of forming a charge transport layer on the charge generation layer.

  First, a coating solution for forming a charge generation layer is prepared. Next, the charge generation layer forming coating solution is applied onto the intermediate layer to form a charge generation layer forming coating solution on the intermediate layer. Next, the charge generation layer is formed by drying the coating film.

  The coating solution for forming the charge generation layer can be prepared, for example, by dispersing a material for the charge generation layer such as the binder resin for the charge generation layer or the charge generation material in a known solvent.

The solvent used in the charge generation layer forming coating solution may be appropriately selected according to the dispersibility of the above components and the coating property to the intermediate layer.
Examples of the solvent used in the coating solution for forming the charge generation layer include methyl ethyl ketone, methyl isopropyl ketone, methyl isobutyl ketone, cyclohexanone, acetophenone, tetrahydrofuran, dioxolane, diethylene glycol dimethyl ether, 2-methoxyethanol, 2-ethoxyethanol, butanol, Ethyl acetate, t-butyl acetate, toluene, chlorobenzene, dichloroethane and trichloroethane are included. The solvent may be one kind or more.

  The means for dispersing the charge generating material can be appropriately selected from known dispersing devices. An example of the means for dispersing the charge generation material is the same as the example of the means for dispersing the titanium oxide particles for the intermediate layer.

  The coating method of the charge generation layer forming coating solution can be appropriately selected from known coating methods according to the composition of the charge generation layer forming coating solution. The example of the coating method of the charge generation layer forming coating solution is the same as the example of the coating method of the intermediate layer forming coating solution.

  The method for drying the coating film of the coating solution for forming the charge generation layer can be appropriately selected according to the type of solvent, the desired thickness of the charge generation layer, and the like. The example of the drying method of the coating film of the charge generation layer forming coating solution is the same as the example of the drying method of the coating film of the intermediate layer forming coating solution.

  Next, a charge transport layer is formed on the charge generation layer. Specifically, first, a charge transport layer coating solution is prepared. Next, the charge transport layer coating solution is applied onto the charge generation layer to form a coating film of the charge transport layer coating solution on the charge generation layer. Finally, the charge transport layer can be formed by drying the coating film.

  The charge transport layer coating solution can be prepared, for example, by dispersing the charge transport layer material such as the charge transport layer binder resin or the charge transport material in a known solvent. Examples of the solvent used in the charge transport layer coating solution are the same as those of the solvent used in the charge generation layer forming coating solution.

  The coating method for the charge transport layer coating solution may be appropriately selected from known coating methods according to the composition of the charge transport layer coating solution. The example of the coating method of the charge transport layer coating solution is the same as the example of the coating method of the intermediate layer forming coating solution.

  The method for drying the coating film of the charge transport layer coating solution can be appropriately selected according to the type of solvent, the desired thickness of the charge transport layer, and the like. The example of the drying method of the coating film of the charge transport layer coating solution is the same as the example of the drying method of the coating film of the intermediate layer forming coating solution.

(D) The process of forming a protective layer The process of forming a protective layer forms a protective layer on a charge transport layer. Specifically, first, a coating liquid for forming a protective layer is prepared. Subsequently, the coating liquid for protective layer formation is apply | coated on a charge transport layer, and the coating film of the coating liquid for protective layer formation is formed on a charge transport layer. Finally, a protective layer is formed by curing the coating film.

  The coating liquid for forming the protective layer is prepared by, for example, dispersing the material for the protective layer such as the radical polymerizable monomer, the metal oxide particles for the protective layer, or the charge transport material for the protective layer in a known solvent. Can be prepared.

  Examples of solvents used in the coating solution for forming the protective layer include methanol, ethanol, n-propyl alcohol, isopropyl alcohol, n-butanol, t-butanol, sec-butanol, benzyl alcohol, toluene, xylene, dichloromethane, and methyl ethyl ketone. , Cyclohexane, ethyl acetate, butyl acetate, 2-methoxyethanol, 2-ethoxyethanol, tetrahydrofuran, 1,3-dioxane, 1,3-dioxolane, pyridine and diethylamine. The solvent may be one kind or more.

  The example of the dispersion | distribution means of the material for protective layers is the same as the example of the dispersion | distribution means of the dispersion means of the titanium oxide particle for intermediate | middle layers. The example of the coating method of the protective layer forming coating solution is the same as the example of the coating method of the intermediate layer forming coating solution.

  The coating liquid for forming a protective layer may further contain other components than the above components as long as the effect of the present embodiment is obtained. Examples of the other components include a radical polymerization initiator. The radical polymerization initiator may be a thermal polymerization initiator or a photopolymerization initiator. The polymerization initiator is preferably a photopolymerization initiator.

  Examples of photopolymerization initiators include diethoxyacetophenone, 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxycyclohexylphenyl-ketone, 4- (2-hydroxyethoxy) phenyl- (2-hydroxy-2-propyl) ketone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butanone-1,2-hydroxy-2-methyl-1-phenylpropan-1-one, Acetophenone-based or ketal-based photopolymerization initiators such as 2-methyl-2-morpholino (4-methylthiophenyl) propan-1-one and 1-phenyl-1,2-propanedione-2- (o-ethoxycarbonyl) oxime Benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isobutyl ether Benzoin ether photopolymerization initiators such as benzoin isopropyl ether; benzophenone, 4-hydroxybenzophenone, methyl o-benzoylbenzoate, 2-benzoylnaphthalene, 4-benzoylbiphenyl, 4-benzoylphenyl ether, acrylated benzophenone, 1,4 -Benzophenone photopolymerization initiators such as benzoylbenzene; and thioxanthone photopolymerization initiation such as 2-isopropylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2,4-dichlorothioxanthone Agent is included.

  Other examples of photopolymerization initiators include ethyl anthraquinone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoylphenylethoxyphosphine oxide, bis (2,4,6-trimethylbenzoyl) Phenylphosphine oxide, bis (2,4-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, methylphenylglyoxyester, 9,10-phenanthrene, acridine compound, triazine compound, and imidazole compound included.

  The polymerization initiator may be one kind or more. The content of the polymerization initiator is in the range of 0.1 to 20 parts by mass and preferably in the range of 0.5 to 10 parts by mass with respect to 100 parts by mass of the radical polymerizable monomer.

  Examples of the method for curing the coating film of the coating liquid for forming the protective layer include irradiation of actinic rays to the coating film and heating of the coating film. Irradiation of the active ray to the coating film can be performed, for example, under known conditions for forming a protective layer by radical reaction of a radical reactive component.

The irradiation energy, irradiation time, and the like of actinic rays can be appropriately set according to the type of light source used, the output of the light source, the type of radical reactive functional group for forming the protective layer, and the like. Irradiation energy of active rays is preferably in the range of 5~500mJ / cm ^2, and more preferably in a range of 5 to 100 mJ / cm ^2. Moreover, it is preferable that irradiation time is 0.1 second-10 minutes, and it is more preferable that it is 0.1 second-5 minutes.

  Examples of types of actinic light sources include low pressure mercury lamps, medium pressure mercury lamps, ultra high pressure mercury lamps, carbon arc lamps, metal halide lamps, xenon lamps, flash (pulse) xenon, and ultraviolet LEDs. The output of the active light source is preferably in the range of 0.1 to 5 kW, and more preferably in the range of 0.5 to 3 kW. Examples of the types of actinic rays include visible light, ultraviolet rays, electron beams, X-rays, and gamma rays. The wavelength of the actinic ray is preferably 250 to 400 nm (ultraviolet light).

Finally, the protective layer is formed by drying the coating film of the coating liquid for forming the protective layer and curing the coating film. The example of the drying method of the coating film of the coating liquid for protective layer formation is the same as the drying method of the coating film of the coating liquid for intermediate | middle layer formation.
As described above, the photoreceptor can be manufactured.

[Electrophotographic image forming method and electrophotographic image forming apparatus]
The electrophotographic image forming apparatus of the present invention uses the above-described electrophotographic photosensitive member of the present invention. In addition, an electrophotographic image forming apparatus of the present invention includes the above-described electrophotographic photosensitive member of the present invention.
Specifically, the electrophotographic image forming apparatus of the present invention preferably includes the electrophotographic photosensitive member of the present invention and has a charging process, an exposure process, a developing process, and a transfer process.

  Hereinafter, an electrophotographic image forming method using the electrophotographic photoreceptor of the present invention and an electrophotographic image forming method will be described. FIG. 1 is a cross-sectional configuration diagram of a full-color electrophotographic image forming apparatus showing an example of an embodiment of the present invention. In the following description, it is assumed that the electrophotographic photoreceptor of the present invention is used for the photoreceptors 1Y, 1M, 1C, and 1Bk.

  This color image forming apparatus is called a tandem type color image forming apparatus, and includes four sets of image forming units 10Y, 10M, 10C, and 10Bk, an endless belt-shaped intermediate transfer body unit 7a, a sheet feeding unit 21, and a fixing unit. Means 24. A document image reading device SC is disposed on the upper part of the main body A of the image forming apparatus.

  An image forming unit 10Y for forming a yellow image includes a charging unit (charging process) 2Y, an exposure unit (exposure process) 3Y, and a developing unit disposed around a drum-shaped photoconductor 1Y as a first image carrier. It has a means (development process) 4Y, a primary transfer roller 5Y as a primary transfer means (transfer process) and a cleaning means 6Y. An image forming unit 10M for forming a magenta image includes a drum-shaped photosensitive member 1M as a first image carrier, a charging unit 2M, an exposure unit 3M, a developing unit 4M, a primary transfer roller 5M as a primary transfer unit, and It has a cleaning means 6M. An image forming unit 10C for forming a cyan image includes a drum-shaped photoreceptor 1C as a first image carrier, a charging unit 2C, an exposure unit 3C, a developing unit 4C, a primary transfer roller 5C as a primary transfer unit, and It has cleaning means 6C. The image forming unit 10Bk that forms a black image includes a drum-shaped photoreceptor 1Bk as a first image carrier, a charging unit 2Bk, an exposure unit 3Bk, a developing unit 4Bk, a primary transfer roller 5Bk as a primary transfer unit, and a cleaning unit. 6Bk.

  The four sets of image forming units 10Y, 10M, 10C, and 10Bk are centered around the photoreceptors 1Y, 1M, 1C, or 1Bk, charging means 2Y, 2M, 2C, or 2Bk, and exposure means 3Y, 3M, 3C, or 3Bk. The developing means 4Y, 4M, 4C or 4Bk and the cleaning means 6Y, 6M, 6C or 6Bk for cleaning the photoreceptors 1Y, 1M, 1C or 1Bk.

  The image forming units 10Y, 10M, 10C, and 10Bk have the same configuration except that the colors of the toner images to be formed on the photoreceptors 1Y, 1M, 1C, and 1Bk are different. Explained.

  The image forming unit 10Y includes a charging unit 2Y (hereinafter also referred to as “charger 2Y”), an exposure unit 3Y, a developing unit 4Y, and a cleaning unit 6Y around a photoconductor 1Y that is an image forming body. A yellow (Y) toner image is formed on the body 1Y. In the present embodiment, in the image forming unit 10Y, at least the photoreceptor 1Y, the charging unit 2Y, the developing unit 4Y, and the cleaning unit 6Y are provided so as to be integrated.

The charging unit 2Y is a unit that applies a uniform potential to the photoreceptor 1Y, and includes a contact charging roller system, a non-contact charging system such as a corona discharge system, and a brush charging system. Among these, it is preferable to use a contact charging roller that contacts the photosensitive member.
Such a contact charging roller (charger 2Y) includes, for example, a charging roller provided in contact with the surface of the photoreceptor 1Y and a power source that applies a voltage to the charging roller. The charging roller is formed, for example, by forming a resistance adjustment layer on a conductive support.

  The exposure unit 3Y is a unit that performs exposure based on an image signal (yellow) on the photoreceptor 1Y to which a uniform potential is applied by the charger 2Y, and forms an electrostatic latent image corresponding to a yellow image. As the exposure means 3Y, an exposure element 3Y composed of an LED having light emitting elements arranged in an array in the axial direction of the photoreceptor 1Y and an imaging element (trade name: SELFOC (registered trademark) lens) or laser optical A system or the like is used.

  The developing means 4Y includes, for example, a developing sleeve and a photosensitive member that have a built-in magnet and rotate while holding the developer, and a voltage applying device that applies a DC and AC bias voltage or a DC or AC bias voltage between the developing sleeve and the developing sleeve. It is made up of.

  The endless belt-shaped intermediate transfer body unit 7a has an endless belt-shaped intermediate transfer body 70 as a semiconductive endless belt-shaped second image carrier wound around a plurality of rollers and rotatably supported.

  Each color image formed by the image forming units 10Y, 10M, 10C, and 10Bk is sequentially transferred onto a rotating endless belt-shaped intermediate transfer body 70 by primary transfer rollers 5Y, 5M, 5C, and 5Bk as primary transfer means. Thus, a synthesized color image is formed. A transfer material P as a transfer material (a support for carrying a fixed final image: for example, plain paper, a transparent sheet, etc.) housed in the paper feed cassette 20 is fed by a paper feed means 21 and a plurality of intermediates. After passing through the rollers 22A, 22B, 22C, 22D and the registration roller 23, they are conveyed to a secondary transfer roller 5b as a secondary transfer means, and are secondarily transferred onto the transfer material P, and the color images are collectively transferred. The transfer material P onto which the color image has been transferred is fixed by the fixing means 24, is sandwiched between the paper discharge rollers 25, and is placed on a paper discharge tray 26 outside the apparatus. Here, a toner image transfer support formed on a photosensitive member such as an intermediate transfer member or a transfer material is collectively referred to as a transfer medium.

  On the other hand, after the color image is transferred to the transfer material P by the secondary transfer roller 5b as the secondary transfer means, the residual toner is removed by the cleaning means 6b from the endless belt-shaped intermediate transfer body 70 in which the transfer material P is separated by curvature. The

  During the image forming process, the primary transfer roller 5Bk is always in contact with the photoreceptor 1Bk. The other primary transfer rollers 5Y, 5M, and 5C are in contact with the corresponding photoreceptors 1Y, 1M, and 1C, respectively, only during color image formation.

  The secondary transfer roller 5b contacts the endless belt-shaped intermediate transfer body 70 only when the transfer material P passes through the secondary transfer roller 5b.

  Further, the housing 8 can be pulled out from the main body A of the image forming apparatus through the support rails 82L and 82R.

  The housing 8 includes image forming units 10Y, 10M, 10C, and 10Bk, and an endless belt-shaped intermediate transfer body unit 7a.

  The image forming units 10Y, 10M, 10C, and 10Bk are arranged in tandem in the vertical direction. An endless belt-shaped intermediate transfer body unit 7a is arranged on the left side of the photoreceptors 1Y, 1M, 1C, and 1Bk in the drawing. The endless belt-shaped intermediate transfer body unit 7a includes an endless belt-shaped intermediate transfer body 70 that can be rotated by winding rollers 71, 72, 76, 73, and 74, primary transfer rollers 5Y, 5M, 5C, and 5Bk, and a cleaning unit 6b. It consists of.

<Static elimination process>
Conventionally, some electrophotographic image forming apparatuses have a configuration capable of performing a static elimination process by light irradiation after transfer, and examples of the static elimination means (photo static elimination apparatus) that perform this process include fluorescent lamps, LEDs, and the like. used. In addition, the light used in the static elimination process is often light having an exposure energy that is at least three times that of the exposure light.
However, in the electrophotographic image forming apparatus employing the photoreceptor of the present invention, it is possible to achieve both long-term memory resistance and prevention of image defects such as black spots and fog without using the above-mentioned charge eliminating means. Therefore, it can be set as the structure which does not have a static elimination means. Thus, it is preferable to use a configuration that does not include an optical charge eliminating device, because it is possible to realize space saving and cost reduction of the image forming apparatus, and to reduce light damage to the photoconductor.

<Process cartridge>
The electrophotographic image forming apparatus of the present invention includes the electrophotographic photosensitive member of the present invention and the above-described charging means (charging device), exposure means (exposure device), developing means (developing device), or cleaning means (cleaning device). It is preferable to configure as a process cartridge (image forming unit) integrally including at least one, and to configure this image forming unit so that it can be inserted into and removed from the electrophotographic image forming apparatus main body (detachable). In addition to a charging unit, an exposure unit, a developing unit, a process cartridge (image forming unit) having at least one of a transfer unit (transfer unit) and a separation unit (separator) together with a photosensitive member is formed. A single image forming unit that is detachably attached to the main body may be used, and a structure that is detachable using guide means such as a rail of the apparatus main body may be used.

  The electrophotographic image forming apparatus of the present invention is generally applicable to electrophotographic image forming apparatuses such as electrophotographic copying machines, laser printers, LED printers, and liquid crystal shutter printers, but also displays, recording, and light printing using electrophotographic technology. It can also be widely applied to apparatuses such as plate making and facsimile.

  The embodiments to which the present invention can be applied are not limited to the above-described embodiments, and can be appropriately changed without departing from the spirit of the present invention.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. In addition, although the display of "part" or "%" is used in an Example, unless there is particular notice, "mass part" or "mass%" is represented.

<Preparation of metal oxide particles 1>
500 parts by mass of anatase-type titanium oxide “JA-1” (manufactured by Teika) having a number average primary particle size of 50 nm, surface modifier: 3-methacryloxypropyltrimethoxysilane “KBM-503” (manufactured by Shin-Etsu Chemical Co., Ltd.) ) After 65 parts by mass and 1500 parts by mass of toluene were stirred and mixed, wet crushing was performed at a temperature of 35 ° C. for 25 minutes with a bead mill, and toluene was separated and removed from the resulting slurry by distillation under reduced pressure. The obtained dried product was heated at 120 ° C. for 2 hours, so that the surface modifier was baked. Thereafter, metal oxide particles 1 (non-surface-modified metal oxide particles not surface-modified with an electron-transporting compound) made of anatase-type titanium oxide, which was pulverized by a pin mill, were obtained.

<Preparation of metal oxide particles 2>
In the production of the metal oxide particles 1, a rutile type titanium oxide “MT-500SA” (manufactured by Teica) having a number average primary particle size of 35 nm was used instead of anatase type titanium oxide. Thus, metal oxide particles 2 (non-surface-modified metal oxide particles not surface-modified with an electron transporting compound) made of organically treated rutile titanium oxide were obtained.

<Preparation of metal oxide particles 3>
In the production of the metal oxide particles 1, a rutile type titanium oxide “MT-100SA” (manufactured by Teika) having a number average primary particle size of 15 nm was used instead of the anatase type titanium oxide. Thus, metal oxide particles 3 (non-surface-modified metal oxide particles not surface-modified with an electron transporting compound) made of organically treated rutile-type titanium oxide were obtained.

<Preparation of metal oxide particles 4>
In the production of the metal oxide particles 1, an organically treated rutile type was used except that titanium oxide having a number average primary particle size of 5 nm was used instead of titanium oxide having a number average primary particle size of 35 nm. Metal oxide particles 4 (non-surface-modified metal oxide particles not surface-modified with an electron transporting compound) made of titanium oxide were obtained.

<Preparation of metal oxide particles 5>
In the production of the metal oxide particles 1, an organically treated rutile type was used in the same manner except that titanium oxide having a number average primary particle size of 200 nm was used instead of titanium oxide having a number average primary particle size of 35 nm. Metal oxide particles 5 (non-surface-modified metal oxide particles not surface-modified with an electron transporting compound) made of titanium oxide were obtained.

<Preparation of metal oxide particles 6>
In the production of the metal oxide particles 2, the same procedure was performed except that methylhydrogenpolysiloxane “MHPS” (manufactured by Shin-Etsu Chemical Co., Ltd.) was used instead of 3-methacryloxypropyltrimethoxysilane as a surface modifier. Thus, metal oxide particles 6 (non-surface-modified metal oxide particles not surface-modified with an electron transporting compound) made of organically treated rutile-type titanium oxide were obtained.

<Preparation of metal oxide particles 7>
In the production of the metal oxide particles 2, an organically treated rutile type was used in the same manner except that titanium oxide having a number average primary particle size of 100 nm was used instead of titanium oxide having a number average primary particle size of 35 nm. Metal oxide particles 7 (non-surface modified metal oxide particles not surface-modified with an electron transporting compound) made of titanium oxide were obtained.

<Preparation of metal oxide particles 8>
In the production of the metal oxide particles 4, organic treatment was performed in the same manner except that tin oxide “CIK” (manufactured by Nanotech) having a number average primary particle size of 5 nm was used instead of rutile titanium oxide. Metal oxide particles 8 (non-surface modified metal oxide particles not surface-modified with an electron transporting compound) made of tin oxide were obtained.

<Preparation of metal oxide particles 9>
In the production of the metal oxide particles 2, an organic material was used in the same manner except that zinc oxide “FZO-50” (manufactured by Ishihara Sangyo Co., Ltd.) having a number average primary particle size of 20 nm was used instead of rutile titanium oxide. Metal oxide particles 9 (non-surface-modified metal oxide particles not surface-modified with an electron transporting compound) made of treated tin oxide were obtained.

<Preparation of metal oxide particles 10-14>
The metal oxide particles 10 to 14 are fine particles (non-surface-modified metal oxide particles that are not surface-modified with an electron transporting compound) before being treated with the surface modifier in the metal oxide particles 1 to 3 and 8 to 9. It is. In addition, as for each metal particle, the fine particle which surface-modified with the inorganic substance is used even if it does not perform the surface treatment by organic substances, such as KBM-503. The surface modification with an inorganic material here is usually treated with an inorganic material such as alumina, aluminum hydroxide, or silica in order to improve (or deactivate) commercially available metal oxide particles such as dispersibility in water. This means treatment with such an inorganic substance.

<Preparation of metal oxide particles 15>
In the production of the metal oxide particles 2, an organically treated rutile type was used except that titanium oxide having a number average primary particle size of 300 nm was used instead of titanium oxide having a number average primary particle size of 35 nm. Metal oxide particles 15 (non-surface-modified metal oxide particles not surface-modified with an electron transporting compound) made of titanium oxide were obtained.
The number average primary particle size shown in Table I below shows the number average primary particle size of the base metal oxide particles before surface modification with each surface modifier, but before and after surface modification. The number average primary particle size is not changed so much that the particle size is changed.

<Preparation of metal oxide particles 2e1>
200 parts by mass of the metal oxide fine particles 2 and 65 parts by mass of the ETM101 as an electron transporting compound and 1500 parts by mass of 2-butanol were stirred and mixed, and then a circulating ultrasonic homogenizer “RUS-600TCVP” The product was dispersed at a circulating flow rate of 40 L / H for 0.5 hours at a temperature of 35 ° C. using a 19.5 kHz, manufactured by Seisakusho, and passed through a 1 μm filter. The obtained dried product was heated at 120 ° C. for 2 hours, thereby baking the surface modifier as an electron transporting compound. Then, it grind | pulverized with the pin mill and obtained the metal oxide particle 2e1 surface-modified with the electron transport compound (ETM).

<Preparation of metal oxide particles 2e2 to 2e8>
In the production of the metal oxide fine particles 2e1, the metal oxide fine particles 2e2 to 2e8 surface-modified with the electron transport compound were similarly obtained except that ETM101, which is an electron transport compound, was changed as shown in Table II below. Got.

<Preparation of metal oxide particles 6e2>
Similarly to the production of the metal oxide particles 2e2, except that the metal oxide particles 6 were used instead of the metal oxide particles 2, the metal oxide particles 6e2 surface-modified with an electron transporting compound were obtained. It was.

<Preparation of metal oxide particles 6e7>
In the production of the metal oxide particles 2e7, metal oxide particles 6e7 surface-modified with an electron transporting compound were obtained in the same manner except that the metal oxide particles 6 were used instead of the metal oxide particles 2. It was.

<Preparation of metal oxide particles 7e5>
In the production of the metal oxide fine particles 2e5, metal oxide fine particles 7e5 surface-modified with an electron transporting compound are obtained in the same manner except that the metal oxide particles 7 are used instead of the metal oxide particles 2. It was.

<Preparation of metal oxide particles 12e5>
In the production of the metal oxide particles 2e5, metal oxide particles 12e5 whose surface is modified with an electron transporting compound are obtained in the same manner except that the metal oxide particles 12 are used instead of the metal oxide particles 2. It was.

<Preparation of metal oxide particles 13e7>
In the production of the metal oxide particles 2e7, the metal oxide particles 13e7 surface-modified with an electron transporting compound were obtained in the same manner except that the metal oxide fine particles 13 were used instead of the metal oxide particles 2. It was.

<Preparation of metal oxide particles 14e7>
In the production of the metal oxide particles 2e7, the metal oxide particles 14e7 whose surface was modified with an electron transporting compound were obtained in the same manner except that the metal oxide particles 14 were used instead of the metal oxide particles 2. It was.
The number average primary particle size shown in Table II below indicates the number average primary particle size of the base metal oxide particles before surface modification with each electron transporting compound (ETM). After the surface modification, there is no change that changes the particle size, and the number average primary particle size is the same value.

<Preparation of Photoreceptor 1>
(1) Preparation of conductive support The surface of a cylindrical aluminum support was cut to prepare a conductive support.
(2-1) Formation of the intermediate layer 1 (in the case of a thermosetting resin)
Phenol resin briofen J-325 (manufactured by DIC)
10 parts by mass Metal oxide particles 1 (Metal oxide particles without ETM treatment, non-surface-modified metal oxide particles)
21 parts by mass of metal oxide particles 2e1 (metal oxide particles with ETM treatment, surface-modified metal oxide particles)
11 parts by mass n-propyl alcohol A composition for intermediate layer 1 consisting of 200 parts by mass was mixed and dispersed by a bead mill as a disperser with a mill residence time of 10 hours. And after leaving this solution still for a whole day and night, the coating liquid for intermediate | middle layer formation was obtained by filtering. Filtration was performed under a pressure of 50 kPa using a rigid mesh filter (manufactured by Nippon Pole Co., Ltd.) having a nominal filtration accuracy of 5 μm as a filtration filter. The intermediate layer-forming coating solution thus obtained is applied to the outer peripheral surface of the washed conductive support by a dip coating method and dried at 140 ° C. for 30 minutes, whereby an intermediate layer 1 having a dry film thickness of 2 μm is obtained. Formed.

(3) Formation of charge generation layer Charge generation material 24 parts by mass (having clear peaks at 8.3 °, 24.7 °, 25.1 °, 26.5 ° by Cu-Kα characteristic X-ray diffraction spectrum measurement) A mixed crystal of 1: 1 addition of titanyl phthalocyanine and (2R, 3R) -2,3-butanediol and non-added titanyl phthalocyanine)
Polyvinyl butyral resin "ESREC BL-1 (manufactured by Sekisui Chemical Co., Ltd.)
12 parts by mass 3-methyl-2-butanone / cyclohexanone = 4/1 (V / V)
A charge generation layer composition composed of 400 parts by mass was mixed, and a circulating ultrasonic homogenizer “RUS-600TCVP (manufactured by Nippon Seiki Seisakusho)” was 0.5 at 19.5 kHz, 600 W at a circulation flow rate of 40 L / H. A charge generation layer coating solution was prepared by dispersing over time.
This charge generation layer coating solution was applied onto the intermediate layer by a dip coating method to form a charge generation layer having a dry film thickness of 0.3 μm.

(4) Formation of charge transport layer The following raw materials were mixed and dissolved to prepare a charge transport layer forming coating solution.
Charge transport material: 4,4′-dimethyl-4 ″-(β-phenylstyryl) triphenylamine) 225 parts by mass Binder resin for charge transport layer: polycarbonate resin “Z300” (Mitsubishi Gas Chemical Co., Ltd.) Inhibitor: “Irganox 1010” (manufactured by BASF Japan)
6 parts by mass Solvent: Tetrahydrofuran 1600 parts by mass Solvent: 400 parts by mass of toluene Leveling agent: Silicone oil “KF-54” (manufactured by Shin-Etsu Chemical Co., Ltd.)
1 part by mass On the charge generation layer, the charge transport layer forming coating solution is applied by a dip coating method to form a coating film, and the coating film is dried to form a charge transport layer having a thickness of 20 μm. Photoconductor 1 was obtained.

<Production of photoconductors 2 to 5 and 7 to 9>
Photoconductors 2 to 5 and 7 to 9 were prepared in the same manner except that the intermediate layer 1 was changed to intermediate layers 2 to 5 and 7 to 9 formed by the following methods in the preparation of the photoconductor 1, respectively. .

(2-2) Formation of intermediate layers 2-5 and 7-9 (in the case of thermosetting resin)
The intermediate layer 1 was formed by the same method except that the metal oxide particles to be added (non-surface-modified metal oxide particles, surface-modified metal oxide particles) were changed as shown in Table III below.

<Production of photoconductors 6 and 18>
Photosensitive members 6 and 18 were prepared in the same manner as in the preparation of the photosensitive member 1, except that the intermediate layer 1 was changed to the intermediate layers 6 and 18 formed by the following methods, respectively.

(2-3) Formation of intermediate layers 6 and 18 (in the case of thermoplastic resin)
Binder resin for intermediate layer: 100 mass parts of polyamide resin (N-1) represented by the following formula (N-1) is mixed with 1700 ethanol / n-propyl alcohol / tetrahydrofuran (volume ratio 45/20/35). In addition to parts by mass, the mixture was stirred and mixed at 20 ° C. 97 parts by mass of metal oxide particles 6 and 226 parts by mass of metal oxide particles 2e5 were added to this solution, and dispersed by a bead mill with a mill residence time of 5 hours. And after leaving this solution still for a whole day and night, the coating liquid for intermediate | middle layer formation was obtained by filtering. Filtration was performed under a pressure of 50 kPa using a rigid mesh filter (manufactured by Nippon Pole Co., Ltd.) having a nominal filtration accuracy of 5 μm as a filtration filter. The intermediate layer-forming coating solution thus obtained is applied to the outer peripheral surface of the washed conductive support by a dip coating method and dried at 120 ° C. for 30 minutes. Formed.
The intermediate layer 18 was also formed in the same manner except that the metal oxide particles to be added were changed as shown in Table III below.

<Production of photoconductors 10 to 17, 19 and 20>
Photoconductors 10-17, 19 and 20 were produced in the same manner except that the intermediate layer 1 was changed to intermediate layers 10-17, 19 and 20 formed by the following methods in the production of the photoreceptor 1, respectively. .

(2-4) Formation of intermediate layers 10-17, 19 and 20 (in the case of visible light curable resin)
Metal oxide particles 10 (metal oxide particles without ETM treatment, non-surface modified metal oxide particles)
80 parts by mass of metal oxide particles 2e7 (metal oxide particles with ETM treatment, surface-modified metal oxide particles)
25 parts by mass The exemplified compound M1 (trimethylolpropane trimethacrylate) (manufactured by Sartomer) 100 parts by mass A-2 (Irgacure 819) (made by BASF Japan) 2 parts by mass B-1 (Irgacure OXE01) (made by BASF Japan) ) 8 parts by mass 2-butanol The composition for intermediate layer 10 consisting of 400 parts by mass was mixed and dispersed with a bead mill as a disperser with a mill residence time of 3 hours. This solution was filtered under a pressure of 50 kPa using a rigid mesh filter (manufactured by Nippon Pole Co., Ltd.) having a nominal filtration accuracy of 5 μm as a filtration filter. The coating solution for forming the intermediate layer thus obtained was applied to the outer peripheral surface of the washed conductive support by a dip coating method, irradiated with a xenon lamp (or metal halide lamp) for 1 minute, and then at 120 ° C. The intermediate layer 10 having a dry film thickness of 2 μm was formed by drying for 30 minutes.
The intermediate layers 11 to 17, 19 and 20 were also formed in the same manner except that the metal oxide particles to be added were changed as shown in Table III below.

<Preparation of Photoreceptor a: Comparative Example>
Photoreceptor a was produced in the same manner as in the production of photoreceptor 1 except that intermediate layer 1 was changed to intermediate layer a formed by the following method.
(2-5) Formation of Intermediate Layer a 100 parts by mass of the polyamide resin (N-1) represented by the formula (N-1) was added to ethanol / n-propyl alcohol / tetrahydrofuran (volume ratio 45/20/35). In addition to 1700 parts by mass of the above mixed solvent, the mixture was stirred and mixed at 20 ° C., 97 parts by mass of metal oxide particles 3 and 226 parts by mass of metal oxide particles 6 were added to this solution, and the mill residence time was 5 hours by a bead mill. As dispersed. The solution was allowed to stand for a whole day and night, and then filtered under a pressure of 50 kPa using a rigid mesh 5 μm filter manufactured by Nippon Pole Co., thereby preparing an intermediate layer a coating solution.
The intermediate layer a thus obtained is applied to the outer peripheral surface of the washed conductive support by a dip coating method and dried at 120 ° C. for 30 minutes, whereby an intermediate layer a having a dry film thickness of 3 μm is obtained. Formed.

<Preparation of Photoreceptor b: Comparative Example>
Photoreceptor b was produced in the same manner as in the production of photoconductor a, except that metal oxide particle 3 was changed from 97 parts by mass to 300 parts by mass and metal oxide particle 6 was removed.

<Preparation of Photoreceptor c: Comparative Example>
Photoreceptor c was produced in the same manner as in the production of photoconductor b, except that metal oxide particles 6e2 were used instead of metal oxide particles 3.

<Preparation of Photoreceptor d: Comparative Example>
Photoreceptor d was prepared in the same manner as in preparation of photoreceptor a, except that intermediate layer a was changed to intermediate layer d formed by the following method.
(2-6) Formation of intermediate layer d In the formation of the intermediate layer 1, the metal oxide particles 1 and the metal oxide particles 2e1 were changed to the metal oxide particles 15 and changed to 30 parts by mass. In the same manner, an intermediate layer d was produced.

<Preparation of Photoreceptor e: Comparative Example>
A photoconductor e was prepared in the same manner as in the production of the photoconductor c, except that the intermediate layer e was formed by the following method.
(2-7) Formation of intermediate layer e In preparation of the intermediate layer 10, the metal oxide particles 10 and the metal oxide particles 2e7 were changed to the metal oxide particles 6e7 and changed to 95 parts by mass. In the same manner, an intermediate layer e was produced.

<Preparation of Photoreceptor f: Comparative Example>
A photoconductor f was prepared in the same manner as in the photoconductor b except that 15 parts by mass of the following ETM-A was further added.

  The ETM-A can be synthesized according to the method disclosed in Japanese Patent No. 4807838.

[Evaluation]
<Durability test>
A full-color copying machine in which the printing speed of a full-color copying machine (bizhub (registered trademark) C658; Konica Minolta Co., Ltd.) was modified to 80 sheets / min was prepared. Each full-color copier is loaded with each of the photoconductors obtained above, and printing is performed continuously for 5 million sheets of text images with an image area ratio of 20% in an A4 landscape feed at a temperature of 30 ° C and a humidity of 85% RH. (After endurance) and the endurance test was conducted. Image memory, black spots and fog were evaluated before (initial) and after the durability test.

(Evaluation of image memory)
Before and after the endurance test, 10 images of a solid black image and a solid white image were continuously printed in an environment of a temperature of 10 ° C. and 15% RH, and then a uniform halftone image was printed. The occurrence of a solid black image and a solid white image in the halftone image, ie, the occurrence of memory, was visually observed and evaluated according to the following evaluation criteria.
"Evaluation criteria"
R5: Memory is not observed in the halftone image (pass)
R4: Slight memory is observed rarely, but there is no practical problem (pass)
R3: Level at which slight memory is observed but no problem in practical use (pass)
R2: Level where clear memory is rarely observed and causes practical problems (fail)
R1: Clear memory is observed (failed)

(Fog evaluation)
Before and after the endurance test, a transfer material “POD gloss coat” (A3 size, 100 g / m ² ) (manufactured by Oji Paper Co., Ltd.), on which no image was formed, was transported to the black position, and the grid voltage was −800V. A solid image (white solid image) was formed under the condition of development bias of −650 V, and the presence or absence of fog on the obtained transfer material was visually observed. Similarly, a yellow solid image was formed under conditions of a grid voltage of −800 V and a developing bias of −650 V, and the presence or absence of fog on the obtained transfer material was visually observed. And it evaluated according to the following evaluation criteria.
"Evaluation criteria"
R5: No fogging is observed in any of the white solid image and the yellow solid image (pass).
R4: In either one of the white solid image and the yellow solid image, a slight fog is observed when the image is enlarged, but there is no practical problem (pass).
R3: Although fog is observed when enlarged in both the white solid image and the yellow solid image, the level is acceptable for practical use (pass)
R2: Slight fogging is visually observed in either one of the white solid image and the yellow solid image (failure).
R1: fog is conspicuously observed in either one of the white solid image and the yellow solid image (failed)

(Black spot evaluation)
Before and after the endurance test, a grid voltage was applied on a transfer material: “A3 / POD gloss coat (A3 size, 100 g / m ² )” (manufactured by Oji Paper Co., Ltd.) in an environment of a temperature of 30 ° C. and a humidity of 80% RH. A solid image (white solid image) was formed under the conditions of −900 V and development bias of −720 V, and the number of black spots with a diameter of 0.1 mm or more in the range of 10 cm × 10 cm on the obtained transfer material was counted. Evaluation was based on the evaluation criteria.
"Evaluation criteria"
R5: No black spot with a diameter of 0.1 mm or more is observed in the range of 10 cm × 10 cm (pass)
R4: 1 to 2 black spots with a diameter of 0.1 mm or more in a range of 10 cm × 10 cm (pass)
R3: 3 to 99 black spots with a diameter of 0.1 mm or more in a range of 10 cm × 10 cm (pass)
R2: 10 to 99 black spots with a diameter of 0.1 mm or more in a range of 10 cm × 10 cm (failed)
R1: 100 or more black spots with a diameter of 0.1 mm or more in the range of 10 cm × 10 cm (failed)

(Dielectric breakdown evaluation)
The presence or absence of dielectric breakdown due to charge leakage of the photoreceptor was evaluated under high temperature and high humidity (temperature 30 ° C., humidity 80% RH) and low temperature and low humidity (temperature 10 ° C., humidity 20% RH).
"Evaluation criteria"
○: Dielectric breakdown due to charge leakage does not occur even under high temperature and high humidity or low temperature and low humidity ×: Dielectric breakdown due to charge leakage occurs even under high temperature and high humidity or low temperature and low humidity (practical problem)

As shown in the above results, it can be seen that when the photoconductor of the present invention is used, image memory, fog, black spots, and dielectric breakdown over a long period of time can be prevented as compared with the photoconductor of the comparative example.
In addition, about the intermediate | middle layer of the photoreceptor of this invention, when the said XPS measurement was performed on the conditions mentioned above, the compound derived from the compound which has a structure represented by the said general formula (Int), and the compound containing a sulfur element, It was confirmed that the content was 0.01 ppm or more.
Moreover, when the cross section of the intermediate layer was observed by the above-described method for the photoreceptor of the present invention, it was confirmed that the surface-modified metal oxide particles were unevenly distributed on the charge generation layer side.

1Y, 1M, 1C, 1Bk photoconductor 2Y, 2M, 2C, 2Bk charging means 3Y, 3M, 3C, 3Bk exposure means 4Y, 4M, 4C, 4Bk developing means 6Y, 6M, 6C, 6Bk cleaning means 10Y, 10M, 10C 10Bk image forming unit

Claims (15)

An electrophotographic photoreceptor in which an intermediate layer and a photosensitive layer are laminated on a conductive support,
The electrophotographic photoreceptor, wherein the intermediate layer contains surface-modified metal oxide particles made of an electron-transporting compound and non-surface-modified metal oxide particles.   2. The electrophotographic photoreceptor according to claim 1, wherein the surface-modified metal oxide particles or the non-surface-modified metal oxide particles contain any element of tin, titanium, and zinc. The electrophotographic photoreceptor according to claim 1, wherein the electron transporting compound is an electron transporting compound represented by the following general formula (ETM).
AX: General formula (ETM)
[In the said general formula (ETM), A represents the mother frame | skeleton of an electron transport compound, and represents the mother frame | skeleton derived from the compound which has a structure represented by either of the following general formula (1)-(9). X represents _{-COOH, -Si (OCH 3) 3} , -Si (OC 2 H 5) 3, or -OH.
X is bonded to any ^one of the substituents R (R ^{1 to} R ⁵⁰ ) in the compounds represented by the following general formulas (1) to (9), and the substituent R at that time has 1 carbon atom. Represents an -8 alkylene group, an optionally substituted cycloalkylene group having 3 to 12 carbon atoms, and an optionally substituted ether group or ester group having 1 to 8 carbon atoms. ]

[In General Formulas (1) to (4) and General Formula (7), R ^{1 to} R ¹⁶ and R ^{31 to} R ⁴⁰ are each independently a hydrogen atom or a carbon number that may have a substituent 1 -8 alkyl group, C3-C12 cycloalkyl group which may have a substituent, C1-C8 alkoxy group which may have a substituent, a halogen atom and a substituent. And a group selected from the group consisting of an optionally substituted aryl group, cyano group, nitro group and hydroxy group, and optionally substituted carbonyl group. Ar ¹ is an arylene group which may have a substituent.
In General Formula (5), R ¹⁷ and R ¹⁸ are each independently a group selected from the group consisting of a hydrogen atom, a cyano group, and an optionally substituted alkoxycarbonyl group having 1 to 8 carbon atoms. And at least one of them is a cyano group or an optionally substituted alkoxycarbonyl group having 1 to 8 carbon atoms, and R ^{19 to} R ²⁶ each independently represents a hydrogen atom, a substituent From a group consisting of an alkyl group having 1 to 8 carbon atoms which may have an aryl group, an aryl group which may have a substituent, and an alkoxycarbonyl group having 1 to 8 carbon atoms which may have a substituent. The group to be selected. Z is a carbon atom or a nitrogen atom.
In General Formula (6), R ²⁷ and R ²⁸ each independently represent a hydrogen atom, an optionally substituted alkyl group having 1 to 8 carbon atoms, or an optionally substituted carbon number. From the group consisting of a 3-12 cycloalkyl group, an optionally substituted alkoxy group having 1 to 8 carbon atoms, a halogen atom, an optionally substituted aryl group, a cyano group, and a nitro group. The group to be selected. p is any of the tetravalent groups represented by the above formulas (p1) to (p5), and has an alkyl group having 1 to 8 carbon atoms and a substituent which may have a substituent. Selected from the group consisting of an optionally substituted alkoxy group having 1 to 8 carbon atoms, a halogen atom, an optionally substituted aryl group having 6 to 18 carbon atoms, a cyano group, a nitro group, and a hydroxy group. It may have at least one substituent.
In general formula (7) and general formula (8), R ²⁹ , R ³⁰ , R ⁴³ and R ⁴⁴ may each independently have a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or a substituent. A good cycloalkyl group having 3 to 12 carbon atoms, an optionally substituted alkoxy group having 1 to 8 carbon atoms, an optionally substituted aryl group having 6 to 18 carbon atoms, a cyano group, and These are groups selected from the group consisting of nitro groups, and these may be linked to each other to have a ring structure.
In General Formula (7), R ⁴¹ and R ⁴² each independently represent a hydrogen atom, an optionally substituted alkyl group having 1 to 8 carbon atoms, or an optionally substituted carbon number. It is a group selected from the group consisting of a 3-12 cycloalkyl group, an optionally substituted alkoxy group having 1 to 8 carbon atoms, and a halogen atom.
In general formula (8) and general formula (9), R ⁴⁵ , R ⁴⁶ and R ^{47 to} R ⁵⁰ may each independently have a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or a substituent. A good cycloalkyl group having 3 to 12 carbon atoms, an optionally substituted alkoxy group having 1 to 8 carbon atoms, a halogen atom, an optionally substituted aryl group, a cyano group, a nitro group, and It is a group selected from the group consisting of a hydroxy group and a heteroaryl group which may have a substituent.
In General Formula (8) and General Formula (9), Q ^{1 to} Q ¹² are each independently a carbon atom or a nitrogen atom. ]   A in the general formula (ETM) is an oxadiazole derivative represented by the general formula (1), a quinone derivative represented by the general formula (4), and a tetracarboxylic acid represented by the general formula (6). The electrophotographic photosensitive member according to claim 3, which represents a mother skeleton derived from a derivative selected from acid diimide derivatives.   5. The number average primary particle size of the surface-modified metal oxide particles or the non-surface-modified metal oxide particles is in a range of 5 to 200 nm. The electrophotographic photoreceptor described in 1.   6. The number average primary particle size of the surface-modified metal oxide particles or the non-surface-modified metal oxide particles is in a range of 10 to 100 nm. The electrophotographic photoreceptor described in 1.   The number average primary particle size of the surface modified metal oxide particles or the non-surface modified metal oxide particles is within a range of 10 to 50 nm, and the surface modified metal oxide particles and the non-surface modified metal oxide The electrophotographic photosensitive member according to any one of claims 1 to 6, wherein the particles have different particle sizes.   The electrophotographic photoreceptor according to any one of claims 1 to 7, wherein the surface-modified metal oxide particles are unevenly distributed on the charge generation layer side.   The electrophotographic photosensitive member according to any one of claims 1 to 8, wherein the intermediate layer is a curable resin layer. 0.01 ppm or more of a compound derived from any one of the compound in which the intermediate layer has a structure represented by the following general formula (Int), a compound containing a phosphorus element other than the compound, or a compound containing a sulfur element The electrophotographic photosensitive member according to claim 9, which is contained.

[In the above general formula (Int), R ₁₀₁ and R ₁₀₂ each independently have a hydrogen atom, a C 1-6 alkyl group which may have a substituent, or a substituent. The group selected from the group which consists of a C3-C6 cycloalkyl group, the aryl group which may have a substituent, a hydroxy group, and a carbonyl group is represented. R ₁₀₁ and R ₁₀₂ may be the same or different. ] An electrophotographic photosensitive member manufacturing method for manufacturing the electrophotographic photosensitive member according to any one of claims 1 to 10,
The method for producing an electrophotographic photoreceptor, wherein the step of forming the intermediate layer includes a visible light curing step of curing with light having a wavelength of 400 nm or more.   An electrophotographic image forming apparatus comprising the electrophotographic photosensitive member according to any one of claims 1 to 10.   13. The electrophotographic image forming apparatus according to claim 12, wherein the charging means in the image forming apparatus is of a contact charging type.   An electrophotographic image forming method using the electrophotographic photosensitive member according to any one of claims 1 to 10.   A process cartridge comprising the electrophotographic photosensitive member according to any one of claims 1 to 10.

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