JP2023164048A - Electrophotographic photoreceptor, process cartridge, electrophotographic device, and method of manufacturing electrophotographic photoreceptor - Google Patents

Abstract

To provide an electrophotographic photoreceptor capable of minimizing density unevenness.SOLUTION: A first layer contains a support material, binder resin, gallium phthalocyanine pigment, and perinone compound selected from a group consisting of compounds represented by a formula (1) and formula (2), and a second layer contains the binder resin and the gallium phthalocyanine pigment.SELECTED DRAWING: Figure 1

Description

The present invention relates to an electrophotographic photoreceptor, a process cartridge using the electrophotographic photoreceptor, an electrophotographic apparatus, and a method for manufacturing an electrophotographic photoreceptor.

As a type of electrophotographic photoreceptor, a laminated photoreceptor is known, which is formed by laminating a charge generation layer containing a charge generation substance and a charge transport layer containing a charge transport substance.

Although the charge generation layer of the laminated photoreceptor can be used as a single layer, it is also known to use the charge generation layer separated into a plurality of layers for the purpose of improving functionality.

In Patent Document 1, disazo pigments with different spectral characteristics are separated and laminated as a charge generation layer, thereby achieving photosensitivity for both a semiconductor laser light source with spectral characteristics in the vicinity of 780 to 800 nm for digital use and a white light source for analog use. A photoreceptor is disclosed.

In Patent Document 2, the charge generation layer has a layer having an n-type semiconductor pigment treated with active energy rays and/or an active gas, and a p-type semiconductor pigment subjected to the same treatment on the charge transport layer side. A technique has been disclosed in which the photosensitive layer has rectifying properties and ensures electrical properties by functionally separating the layers.

Patent Document 3 focuses on the fact that the contact between the charge transport material and the charge generation material at the interface between the charge transport layer and the charge generation layer greatly affects the quantum efficiency, and the charge of vanadyl phthalocyanine used as the charge generation material is This is a technology in which layers with different content ratios in the generation layer are laminated one above the other. By increasing the concentration of the charge generation material on the charge transport layer side compared to the layer on the substrate side, it is possible to achieve high sensitivity and low residual potential. A technique for obtaining a body is disclosed.

In Patent Document 4, in order to solve the problem that sensitivity decreases due to an increase in surface charge density due to an increase in capacitance when the film thickness decreases due to mechanical abrasion after long-term repeated use, the incident light transmission of the photosensitive layer is disclosed. A photoreceptor is disclosed that can be used while maintaining sensitivity even if the film thickness decreases after long-term repeated durability by providing a plurality of layers with different sensitivities with adjusted depths.

Japanese Patent Application Publication No. 05-040352 Japanese Patent Application Publication No. 10-268533 Japanese Patent Application Publication No. 07-020645 Japanese Patent Application Publication No. 2002-139851

However, it has been found that when a charge generation layer is used in a stacked structure, an increase in local dark decay becomes a problem as the amount of charge generation material in the layer increases. Specifically, due to the increase in dark decay, a fogging phenomenon in non-image areas (a phenomenon in which toner is developed in areas where the charging potential has decreased) may occur. In addition, the occurrence of areas where dark attenuation locally increases within the plane causes unevenness (spots) in the charging potential and exposure potential, which worsens the graininess of the image when outputting a halftone image (hereinafter referred to as "halftone"). (Also called "unevenness in image density occurs.")

An object of the present invention is to provide an electron beam that sufficiently suppresses in-plane dark decay unevenness when a charge generation layer is formed in a laminated type photosensitive layer and achieves the high level of image quality that has been sought in recent years. An object of the present invention is to provide a photographic photoreceptor, and a process cartridge and an electrophotographic apparatus using the electrophotographic photoreceptor.

式（１）中、Ｒ^１１～Ｒ^１８は、及び、式（２）中、Ｒ^２１～Ｒ^２８は、それぞれ独立に、水素原子、ハロゲン原子、置換若しくは無置換のアルキル基、置換若しくは無置換のアリール基、置換若しくは無置換のアリールオキシ基、置換若しくは無置換のアルコキシカルボニル基を示す。Ｒ^１１～Ｒ^１４、Ｒ^１５～Ｒ^１８、Ｒ^２１～Ｒ^２４及びＲ^２５～Ｒ^２８の各群の中で隣り合う基同士は連結して共同して環を形成してもよい。 The above object is achieved by the present invention as follows. That is, the present invention provides an electrophotographic photoreceptor comprising a support, a first layer, a second layer, and a charge transport layer in this order,
The first layer includes a binder resin, a gallium phthalocyanine pigment, and at least one type of perinone compound selected from the group consisting of a perinone compound represented by the following formula (1) and a perinone compound represented by the following formula (2). Contains a perinone compound,
The electrophotographic photoreceptor is characterized in that the second layer contains a binder resin and a gallium phthalocyanine pigment.

In formula (1), R ¹¹ to R ¹⁸ are, and in formula (2), R ²¹ to R ²⁸ are each independently a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted alkyl group. represents an aryl group, a substituted or unsubstituted aryloxy group, or a substituted or unsubstituted alkoxycarbonyl group. Adjacent groups in each group of R ¹¹ to R ¹⁴ , R ¹⁵ to R ¹⁸ , R ²¹ to R ²⁴ and R ²⁵ to R ²⁸ may be connected to each other to jointly form a ring.

Further, the present invention provides a process cartridge that integrally supports the electrophotographic photoreceptor and at least one means selected from the group consisting of charging means, developing means, and cleaning means, and is detachably attached to the main body of the electrophotographic apparatus. It is.

Further, the present invention is an electrophotographic apparatus having the above electrophotographic photoreceptor, charging means, exposure means, developing means, and transfer means.

The present invention also provides a method for manufacturing an electrophotographic photoreceptor, which comprises a support, a first layer, a second layer, and a charge transport layer in this order.
The manufacturing method includes:
A binder resin and/or a monomer for a binder resin, a gallium phthalocyanine pigment, and at least one perinone compound selected from the group consisting of a compound represented by the above formula (1) and a compound represented by the above formula (2). a step of preparing a first layer coating solution containing;
A coating film of the first layer coating solution is formed on the support, and the coating film of the first layer coating solution is dried and/or cured to form a coating film of the first layer coating solution on the support. a step of forming a layer;
preparing a second layer coating solution containing a binder resin and/or a monomer for the binder resin, and a gallium phthalocyanine pigment;
A coating film of the second layer coating liquid is formed on the second layer, and the coating film of the second layer coating liquid is dried and/or cured to form a coating film on the first layer. forming the second layer, and
A method for producing an electrophotographic photoreceptor, comprising a step of forming the charge transport layer on the second layer.

According to the present invention, an electrophotographic photoreceptor that sufficiently suppresses in-plane dark decay unevenness and suppresses density unevenness of a high-level halftone image that has been sought in recent years, and an electrophotographic photoreceptor using such an electrophotographic photoreceptor. A process cartridge, an electrophotographic apparatus, and a method for manufacturing such an electrophotographic photoreceptor can be provided.

FIG. 1 is a diagram showing an example of a layer structure of an electrophotographic photoreceptor according to the present invention. 1 is a diagram illustrating an example of a schematic configuration of an electrophotographic apparatus including a process cartridge having an electrophotographic photoreceptor according to the present invention.

Hereinafter, the present invention will be described in detail by citing preferred embodiments.
[Electrophotographic photoreceptor]
The electrophotographic photoreceptor of the present invention has a support and a laminated photosensitive layer formed on the support. FIG. 1 is a diagram showing an example of the layer structure of an electrophotographic photoreceptor. In FIG. 1, 101 is a support, 102 is an undercoat layer, 103 is a first layer, and 104 is a second layer. 105 is a charge transport layer. In the present invention, the subbing layer 102 may be omitted.

<Support>
The support is preferably one that has conductivity (conductive support), such as a support made of metal (alloy) such as aluminum, iron, copper, gold, stainless steel, or nickel, or a support with a conductive film on the surface. Examples include metal and insulating supports provided with . Examples of the insulating support include supports made of plastic such as polyester resin, polycarbonate resin, and polyimide resin, glass, and paper. Examples of conductive films include thin films of metals such as aluminum, chromium, silver, and gold, thin films of conductive materials such as indium oxide, tin oxide, and zinc oxide, and thin films of conductive ink containing silver nanowires. It will be done.

The shape is preferably cylindrical. Further, the surface of the support may be subjected to electrochemical treatment such as anodic oxidation, blasting treatment, cutting treatment, or the like.

Moreover, examples of the shape of the support include a cylindrical shape and a film shape. Among these, a cylindrical aluminum support is excellent in terms of mechanical strength, electrophotographic properties, and cost. Although the tube may be used as a support as it is, physical treatments such as cutting, honing, and blasting, or anodizing or anodizing treatment may be applied to the surface of the tube to improve electrical characteristics and suppress interference fringes. A material that has been subjected to a chemical treatment using an acid or the like may be used as the support.

<Conductive layer>
The conductive layer is a layer that may be provided if necessary.
The conductive layer is arranged on the conductive support and between the conductive support and the photosensitive layer, more specifically, the conductive support, the conductive layer, the undercoat layer, and the photosensitive layer are arranged in this order. This is a good layer.
By providing the conductive layer, it is possible to hide scratches and irregularities on the surface of the conductive support, and to control the reflection of light on the surface of the support.
The conductive layer contains conductive particles and resin.

Examples of the material of the conductive particles include metal oxides, metals, and carbon black.
Examples of metal oxides include zinc oxide, aluminum oxide, indium oxide, silicon oxide, zirconium oxide, tin oxide, titanium oxide, strontium titanate, magnesium oxide, antimony oxide, and bismuth oxide.
Examples of metals include aluminum, nickel, iron, nichrome, copper, zinc, and silver.
Among the above-mentioned materials for the conductive particles, metal oxides are preferred, and titanium oxide, tin oxide, and zinc oxide are particularly preferred.
Regarding the metal oxide, the surface of the metal oxide may be treated with a silane coupling agent or the like, or may be doped with an element itself such as phosphorus or aluminum or an oxide thereof.
Further, the conductive particles may have a laminated structure including a core material and a coating layer covering the core material. Examples of the core material include titanium oxide, barium sulfate, and zinc oxide. Examples of the coating layer include metal oxides such as tin oxide.
The coating layer and the surface treated with the silane coupling agent are much thicker than the latter.
Further, when using a metal oxide as the conductive particles, the volume average particle size thereof is preferably 1 nm or more and 500 nm or less, more preferably 3 nm or more and 400 nm or less.

Examples of the resin include polyester resin, polycarbonate resin, polyvinyl acetal resin, acrylic resin, silicone resin, epoxy resin, melamine resin, polyurethane resin, phenol resin, and alkyd resin.
Furthermore, the conductive layer may contain silicone oil, resin particles, a masking agent such as titanium oxide, and the like.

The conductive layer can be obtained by providing a coating film of a conductive layer coating solution containing each of the above-mentioned materials and a solvent on a support, and drying the coating film.

Examples of the solvent used in the coating solution include alcohol solvents, sulfoxide solvents, ketone solvents, ether solvents, ester solvents, and aromatic hydrocarbon solvents.

Dispersion methods for dispersing conductive particles in the conductive layer coating solution include methods using a paint shaker, a sand mill, a ball mill, and a liquid collision type high-speed dispersion machine.

The average thickness of the conductive layer is preferably 0.1 μm or more and 50 μm or less, particularly preferably 3 μm or more and 40 μm or less.

<Undercoat layer>
An undercoat layer having a barrier function or an adhesive function may be provided on the support or the conductive layer, if necessary. The undercoat layer is obtained by dissolving a resin in a solvent to prepare an undercoat layer coating solution, forming a coating film of the undercoat layer coating solution, and drying it. The undercoat layer contains resin and a substance that improves electrical properties. Let me explain each one.

The undercoat layer contains resin. Alternatively, the resin may be used to obtain the undercoat layer as a cured film obtained by polymerizing a composition containing a monomer having a polymerizable functional group in the coating solution (curing by polymerization of the monomer). .

As resins, polyester resin, polycarbonate resin, polyvinyl acetal resin, acrylic resin, epoxy resin, melamine resin, polyurethane resin, phenol resin, polyvinylphenol resin, alkyd resin, polyvinyl alcohol resin, polyethylene oxide resin, polypropylene oxide resin, polyamide resin, Examples include polyamic acid resin, polyimide resin, polyamideimide resin, and cellulose resin.

Polymerizable functional groups possessed by monomers having polymerizable functional groups include isocyanate groups, blocked isocyanate groups, methylol groups, alkylated methylol groups, epoxy groups, metal alkoxide groups, hydroxyl groups, amino groups, carboxyl groups, thiol groups, and carboxyl groups. Examples include acid anhydride groups and carbon-carbon double bond groups.

Further, the undercoat layer contains an electron transport substance, a metal oxide, a metal, etc. for the purpose of improving electrical properties. Among these, it is preferable to use electron transport substances and metal oxides.
Examples of electron transport substances include quinone compounds, imide compounds, benzimidazole compounds, cyclopentadienylidene compounds, fluorenone compounds, xanthone compounds, benzophenone compounds, cyanovinyl compounds, halogenated aryl compounds, silole compounds, boron-containing compounds, etc. . An undercoat layer may be formed as a cured film by using an electron transporting material having a polymerizable functional group as the electron transporting material and copolymerizing it with the above-mentioned monomer having a polymerizable functional group.
Examples of metal oxides include indium tin oxide, tin oxide, indium oxide, titanium oxide, zinc oxide, aluminum oxide, strontium titanate, and silicon dioxide. Examples of metals include gold, silver, and aluminum.

The metal oxide contained in the undercoat layer may be used after surface treatment using a surface treatment agent such as a silane coupling agent.
A general method is used to surface treat the metal oxide. Examples include a dry method and a wet method.
In the dry method, a metal oxide is stirred in a high-speed mixer such as a Henschel mixer, and an alcohol aqueous solution, an organic solvent solution, or an aqueous solution containing a surface treatment agent is added, and the mixture is uniformly dispersed. It is used for drying.
In addition, in the wet method, the metal oxide and surface treatment agent are stirred in a solvent or dispersed in a sand mill using glass beads, etc. After dispersion, the solvent is removed by filtration or distillation under reduced pressure. be exposed. After removing the solvent, it is preferable to further bake at 100° C. or higher.

The undercoat layer may further contain additives, for example, metal powder such as aluminum, conductive substances such as carbon black, metal chelate compounds, organometallic compounds, and other known materials. can.

The undercoat layer can be formed by preparing an undercoat layer coating solution containing each of the above materials and a solvent, forming this coating on a support or conductive layer, and drying and/or curing. can.

Examples of the solvent used in the coating solution for the undercoat layer include organic solvents such as alcohols, sulfoxides, ketones, ethers, esters, aliphatic halogenated hydrocarbons, and aromatic compounds. In the present invention, it is preferable to use alcohol-based or ketone-based solvents.

Dispersion methods for preparing the coating solution for the undercoat layer include methods using a homogenizer, an ultrasonic disperser, a ball mill, a sand mill, a roll mill, a vibration mill, an attritor, and a liquid impingement type high-speed disperser.

When using an undercoat layer, the average thickness is preferably 0.05 μm or more and 50 μm or less, more preferably 0.3 μm or more and 25 μm or less.

<First layer and second layer>
The electrophotographic photoreceptor of the present invention has a first layer containing a binder resin, a gallium phthalocyanine pigment, and a perinone compound, and a second layer containing a binder resin and a gallium phthalocyanine pigment.

In an electrophotographic image forming apparatus, in order to reproduce halftones of an image, a method of reproducing gradations by halftone processing using a screen pattern is generally adopted. However, there is a problem in that the reproducibility of halftone dots in highlight areas is unstable, and this is recognized as noise, resulting in worsening of graininess. One of the causes of such instability is uneven charging of the photoreceptor. Charging unevenness on a photoreceptor refers to microscopic unevenness in the charged potential within the surface of the photoreceptor due to some reason, resulting in uneven exposure potential within the surface during image exposure irradiation, resulting in unstable reproducibility of halftone dots and grainy This is a phenomenon that worsens.

Such microscopic unevenness in charging potential occurs significantly when the charge generation layer is used in a laminated structure. That is, an increase in the absolute amount of the charge-generating material in the layer causes in-plane unevenness in dark decay, resulting in uneven charging potential, leading to deterioration of graininess.

As a result of studies, the present inventors discovered that a binder resin, a gallium phthalocyanine pigment, and at least one member selected from the group consisting of a perinone compound represented by formula (1) and a perinone compound represented by formula (2) By using the first layer containing the perinone compound, the binder resin, and the second layer containing the gallium phthalocyanine pigment separately, it is possible to suppress in-plane dark attenuation unevenness and produce images with good graininess. was found to be obtained.

The inventors believe that the reason why uneven charging, that is, uneven dark decay can be suppressed by such a configuration, is as follows. One of the causes of worsening dark decay of a photoreceptor is injection of "thermally excited carriers" generated from the charge generation material in the charge generation layer into the charge transport layer. Organic pigments used as charge-generating materials have energy bands due to overlapping molecules. Since the crystallinity of organic pigments is not as high as that of inorganic pigments, they have bands consisting of multiple levels corresponding to the overlapping pattern of multiple molecules. Among these levels, there are levels that are excited by heat around room temperature, so thermally excited carriers are generated in the charge generation layer of the photoreceptor at room temperature even in an unexposed state. It is thought that these carriers are injected into the charge transport layer in response to the electric field during charging, thereby lowering the surface charging potential.

The amount of thermally excited carriers increases as the amount of charge-generating material in the layer increases, so when a stacked layer is used, the amount of dark decay becomes larger than when a single layer is used.

Furthermore, since the charge-generating material exists as a pigment dispersed in the film, an excessive amount of thermally excited carriers is distributed in the plane according to the distribution of the pigment in the film, and dark decay unevenness occurs in the plane according to the distribution. It is thought that this will occur.

In the present invention, dark decay can be suppressed by mixing a perinone compound into a film having a gallium phthalocyanine pigment as a charge-generating material. The present inventors believe that this is because it can interfere with the existing bands and promote recombination.

Furthermore, the ability to suppress dark decay unevenness changes depending on the placement and film thickness of the perinone compound and gallium phthalocyanine pigment. These preferred ranges are as follows.

(Suitable range of first layer)
The content of the perinone compound in the first layer is preferably 50% by mass or more and 1000% by mass or less based on the content of the gallium phthalocyanine pigment. If this content is less than 50% by mass, the effect of suppressing dark decay expected in the present invention cannot be obtained, and if it exceeds 1000% by mass, potential fluctuations will worsen. It is thought that when perinone is present in excess of the gallium phthalocyanine pigment, the potential fluctuation becomes worse because it inhibits the generation of not only thermally excited carriers but also carriers generated by exposure.

Further, when the content of the gallium phthalocyanine pigment in the first layer is 5% by mass or more and 50% by mass or less based on the total mass of the first layer, the effects of the present invention are enhanced. If it is less than 5% by mass, sufficient charge generation ability of the gallium phthalocyanine pigment itself cannot be obtained, and potential fluctuations are worsened by carriers retained in the film, making it unsuitable for long-term use. When the proportion of the gallium phthalocyanine pigment in the film exceeds 50% by mass, the effect of suppressing dark decay by perinone cannot be obtained, and graininess worsens due to worsening of dark decay.

Furthermore, the thickness of the first layer is preferably 2 μm or more and 20 μm or less. When the thickness of the first layer is thinner than 2 μm, dark attenuation due to local hole injection increases, resulting in worsening of graininess. Although the effects of the present invention can be highly obtained even if the film is thicker than 20 μm, if the film is thicker than this, problems occur in film formability.

(Suitable range of second layer)
The second layer may contain a perinone compound, but the content of the perinone compound is preferably 1% by mass or less based on the content of the gallium phthalocyanine pigment. When the content of the perinone compound exceeds 1% by mass, long-term potential fluctuations worsen. The reason for this is presumed to be that the presence of a large amount of perinone compounds at the layer interface between the charge transport layer and the charge generation layer inhibits the transfer of positive charges from the charge generation layer to the charge transport layer.

Further, the content of the gallium phthalocyanine pigment in the second layer is preferably 50% by mass or more and 75% by mass or less based on the total mass of the second layer. Within this range, graininess is improved. When the content of gallium phthalocyanine pigment is less than 50% by mass, sensitivity deteriorates. If it exceeds 75% by mass, the increase in dark decay caused by the second layer exceeds the dark decay suppressing effect of perinone supported in the first layer, resulting in worsening of graininess.

Further, the thickness of the second layer is preferably 0.1 μm or more and 0.5 μm or less. If it is thinner than 0.1 μm, film formability deteriorates. When the film thickness is thicker than 0.5 μm, dark decay deteriorates and the effect of improving graininess becomes weaker.

(Gallium phthalocyanine pigment)
The charge-generating substance contains a hydroxygallium phthalocyanine pigment or a chlorogallium phthalocyanine pigment (hereinafter, the two types are also simply referred to as "phthalocyanine pigment"). These may have an axial ligand or a substituent.

Hydroxygallium phthalocyanine pigments include hydroxygallium phthalocyanine crystals that have strong peaks at Bragg angles (2θ±0.2°) of 7.3°, 24.9°, and 28.1° in CuKα characteristic X-ray diffraction. and strong peaks at Bragg angles (2θ±0.2°) of 7.5°, 9.9°, 12.5°, 16.3°, 18.6°, 25.1° and 28.3°. Hydroxygallium phthalocyanine crystals having a crystal form and Bragg angle (2θ ± 0.2°) of 7.5°, 9.9°, 12.5°, 16.3°, 18.6°, 25.1 Hydroxygallium phthalocyanine crystals in the form of crystals having strong peaks at 28.3° and 28.3° are preferred.

Chlorogallium phthalocyanine is a crystalline form with strong peaks at Bragg angles (2θ±0.2°) of 7.4°, 16.6°, 25.5°, and 28.2° in CuKα characteristic X-ray diffraction. Chlorogallium phthalocyanine crystals, chlorogallium phthalocyanine crystals with strong peaks at Bragg angles (2θ ± 0.2°) of 6.8°, 17.3°, 23.6° and 26.9°, Chlorogallium in crystalline form with strong peaks at Bragg angles (2θ±0.2°) of 8.7°, 9.2°, 17.6°, 24.0°, 27.4° and 28.8° Phthalocyanine crystals are preferred.

式（１）中、Ｒ^１１～Ｒ^１８及び式（２）中、Ｒ^２１～Ｒ^２８は、それぞれ独立に、水素原子、ハロゲン原子、置換若しくは無置換のアルキル基、置換若しくは無置換のアリール基、置換若しくは無置換のアリールオキシ基、置換若しくは無置換のアルコキシカルボニル基を示す。Ｒ^１１～Ｒ^１４、Ｒ^１５～Ｒ^１８、Ｒ^２１～Ｒ^２４及びＲ^２５～Ｒ^２８の各群の中で隣り合う基同士は連結して共同して環を形成してもよい。 (Perinone compound)
The perinone compound in the present invention is at least one compound selected from the group consisting of perinone compound (1) and perinone compound (2). Perinone compound (1) is a compound represented by the following formula (1). Perinone compound (2) is a compound represented by the following formula (2).

In formula (1), R ¹¹ to R ¹⁸ and in formula (2), R ²¹ to R ²⁸ each independently represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group. , a substituted or unsubstituted aryloxy group, or a substituted or unsubstituted alkoxycarbonyl group. Adjacent groups in each group of R ¹¹ to R ¹⁴ , R ¹⁵ to R ¹⁸ , R ²¹ to R ²⁴ and R ²⁵ to R ²⁸ may be connected to each other to jointly form a ring.

The alkyl group is a straight-chain or branched alkyl whose main chain has 1 or more and 10 or less atoms.
In particular, from the viewpoint of suppressing graininess, a branched chain alkyl having 3 or more and 10 or less carbon atoms is preferable.

R ¹¹ to R ¹⁸ in formula (1) are preferably each independently a branched alkyl group having 3 to 10 carbon atoms, as shown by R ³¹ and R ³² in formula (3). Further, as shown in formula (6) of R ⁵¹ to R ⁵⁶ of formula (5), a methyl group, an ethyl group, or a propyl group is preferable.
R ²¹ to R ²⁸ in formula (2) are preferably each independently a branched alkyl group having 3 or more and 10 or less carbon atoms, as shown by R ⁴¹ and R ⁴² in formula (4). Furthermore, it is more preferable that R ⁶¹ to R ⁶⁶ in formula (6) each independently represent a methyl group, an ethyl group, or a propyl group.

In the above formulas (1) and (2),
Examples of substituents for the alkyl group include a halogen atom, an aryl group, and an alkoxycarbonyl group.
Examples of substituents on the aryl group include a halogen atom, an alkyl group, and an alkoxycarbonyl group. Aryl groups having 6 to 10 carbon atoms are preferred, and phenyl groups are particularly preferred.
Examples of substituents for the aryloxy group include a halogen atom, an alkyl group, and an alkoxycarbonyl group. An aryloxy group having 6 to 10 carbon atoms is preferred, and a phenyloxy group is particularly preferred.
Examples of substituents for the alkoxycarbonyl group include a halogen atom and an aryl group. An alkoxycarbonyl group having 1 to 10 carbon atoms is preferred, and a methoxycarbonyl group, an ethoxycarbonyl group and a propoxycarbonyl group are particularly preferred.
Adjacent groups in each group of R ¹¹ to R ¹⁴ , R ¹⁵ to R ¹⁸ , R ²¹ to R ²⁴ and R ²⁵ to R ²⁸ may be connected to each other to jointly form a ring. It is particularly preferable that the ring forms an aromatic ring, and the aromatic ring is preferably a naphthalene ring or an anthracene ring.

Specific examples (1-1) to (1-17) of perinone compound (1) and specific examples (2-1) to (2-17) of perinone compound (2) are shown below, but this embodiment is not limited to this.

The first layer and second layer according to the present invention are manufactured by the following method.
For the first layer, a coating solution for the first layer is prepared by dispersing a binder resin and/or a monomer for the binder resin, a gallium phthalocyanine pigment, and a perinone compound in a solvent, and a coating film coated with the coating solution is dried and /or obtained by curing. For the second layer, a coating solution for the second layer is prepared by dispersing a binder resin and/or a monomer for the binder resin and a gallium phthalocyanine pigment in a solvent, and a coating film coated with this is dried and/or Obtained by curing.

The coating solution may be prepared by adding only gallium phthalocyanine and a perinone compound to a solvent, dispersing the mixture, and then adding a binder resin and/or a monomer for the binder resin, or by adding gallium phthalocyanine, a perinone compound, a binder resin, and a monomer for the binder resin. Alternatively, the monomer for the binder resin may be added to a solvent and dispersed therein.

In the case of the above-mentioned dispersion, a media type dispersion machine such as a sand mill or a ball mill, a dispersion machine such as a liquid collision type dispersion machine or an ultrasonic dispersion machine can be used.

Examples of the binder resin used in the first layer and the second layer include polyvinyl butyral resin, polyvinyl acetal resin, polyarylate resin, polycarbonate resin, polyester resin, polyvinyl acetate resin, polysulfone resin, polystyrene resin, and phenoxy resin. , acrylic resin, phenoxy resin, polyacrylamide resin, polyvinylpyridine resin, urethane resin, agarose resin, cellulose resin, casein resin, polyvinyl alcohol resin, polyvinylpyrrolidone resin, vinylidene chloride resin, acrylonitrile copolymer and polyvinylbenzal resin, etc. Examples include resins (insulating resins). Also, organic photoconductive polymers such as poly-N-vinylcarbazole, polyvinylanthracene, polyvinylpyrene, etc. can also be used. Moreover, only one type of binder resin may be used, or two or more types may be used in combination as a mixture or a copolymer. Alternatively, the resin may be obtained as a cured film obtained by forming a coating solution into a coating (curing by polymerization of monomers) by polymerizing a composition containing a monomer having a polymerizable functional group in the coating solution. The binder resin-like monomer has a polymerizable functional group, and examples of the polymerizable functional group include an isocyanate group, a blocked isocyanate group, a methylol group, an alkylated methylol group, an epoxy group, a metal alkoxide group, a hydroxyl group, and an amino group. group, carboxyl group, thiol group, carboxylic acid anhydride group, carbon-carbon double bond group, etc.

The same binder resin may be used for the first layer and the second layer, but different resins are selected from the viewpoint of adhesion to the charge transport layer and prevention of elution of the charge generating material into the charge transport layer. That's good.

Examples of solvents used in the coating solution include toluene, xylene, tetralin, chlorobenzene, dichloromethane, chloroform, trichloroethylene, tetrachloroethylene, carbon tetrachloride, methyl acetate, ethyl acetate, propyl acetate, methyl formate, ethyl formate, acetone, methyl ethyl ketone, Cyclohexanone, diethyl ether, dipropyl ether, propylene glycol monomethyl ether, dioxane, methylal, tetrahydrofuran, water, methanol, ethanol, n-propanol, isopropanol, butanol, methyl cellosolve, methoxypropanol, dimethylformamide, dimethylacetamide, dimethyl sulfoxide, etc. Can be mentioned. Further, one or more solvents can be used alone or in combination.

<Charge transport layer>
For the charge transport layer, a charge transport layer coating solution is prepared by dissolving or dispersing a charge transport substance and, if necessary, a binder resin in a solvent, and a coating film of the charge transport layer coating solution is formed and dried. obtained by.

Examples of the charge transport substance include triarylamine compounds, hydrazone compounds, stilbene compounds, pyrazoline compounds, oxazole compounds, thiazole compounds, and triallylmethane compounds. Also included are polymers having groups derived from these compounds in their main chains or side chains. Among these, triarylamine compounds, styryl compounds, or benzidine compounds are preferable as the charge transporting substance, and triarylamine compounds are particularly preferable. Furthermore, one or more charge transport substances can be used alone or in combination.

Examples of the binder resin used in the charge transport layer include polyvinyl butyral resin, polyvinyl acetal resin, polyarylate resin, polycarbonate resin, polyester resin, polyvinyl acetate resin, polysulfone resin, polystyrene resin, phenoxy resin, polyvinyl acetate resin, Acrylic resin, phenoxy resin, polyacrylamide resin, polyamide resin, polyvinylpyridine resin, cellulose resin, urethane resin, epoxy resin, agarose resin, cellulose resin, casein resin, polyvinyl alcohol resin, polyvinylpyrrolidone resin, vinylidene chloride resin, acrylonitrile resin, etc. Examples include polymers and resins (insulating resins) such as polyvinylbenzal resin. Also, organic photoconductive polymers such as poly-N-vinylcarbazole, polyvinylanthracene, polyvinylpyrene, etc. can also be used. Among these, polycarbonate resins and polyarylate resins are preferred. Moreover, only one type of binder resin may be used, or two or more types may be used in combination as a mixture or a copolymer. The copolymerization form may be any form such as a block copolymer, random copolymer, or alternating copolymer. Moreover, the weight average molecular weight (Mw) of these molecules is preferably in the range of 10,000 to 300,000.

The content of the charge transport substance in the charge transport layer is preferably from 20% by mass to 80% by mass, more preferably from 30% by mass to 60% by mass, based on the total mass of the charge transport layer.
The thickness of the charge transport layer is preferably 5 μm or more and 40 μm or less.

<Protective layer>
A protective layer may be provided on the photosensitive layer, if necessary. The protective layer is obtained by dissolving a resin in an organic solvent to prepare a protective layer coating solution, forming a coating film of the protective layer coating solution, and drying it. The protective layer can also be formed by curing the coating film by heating, electron beams, ultraviolet rays, or the like.

Resins used for the protective layer include polyvinyl butyral resin, polyester resin, polycarbonate resin (polycarbonate Z resin, modified polycarbonate resin, etc.), nylon resin, polyimide resin, polyarylate resin, polyurethane resin, styrene-butadiene copolymer, styrene. - acrylic acid copolymers and styrene-acrylonitrile copolymers.

Further, in order to provide the protective layer with charge transport ability, the protective layer may be formed by curing monomers having charge transport ability using various polymerization reactions and crosslinking reactions. Specifically, it is preferable to form the protective layer by polymerizing or crosslinking and curing a charge transporting compound having a chain polymerizable functional group.

Further, the protective layer may contain conductive particles, ultraviolet absorbers, lubricating particles such as fluorine atom-containing resin particles, and the like. As the conductive particles, metal oxide particles such as tin oxide particles are preferred. The thickness of the protective layer is preferably 0.05 μm or more and 20 μm or less.

As a coating method for each layer, coating methods such as a dipping method, a spray coating method, a spinner coating method, a bead coating method, a blade coating method, and a beam coating method can be used. Among these, the dip coating method is preferred from the viewpoint of efficiency and productivity.

[Process cartridge and electrophotographic device]
FIG. 2 shows an example of a schematic configuration of an electrophotographic apparatus having a process cartridge equipped with an electrophotographic photoreceptor. In FIG. 2, reference numeral 1 denotes a cylindrical (drum-shaped) electrophotographic photoreceptor, which is rotated around a shaft 2 in the direction of the arrow at a predetermined circumferential speed (process speed).

The surface of the electrophotographic photoreceptor 1 is charged to a predetermined positive or negative potential by the charging means 3 during the rotation process. Next, the surface of the charged electrophotographic photoreceptor 1 is irradiated with exposure light 4 from an exposure means (not shown) to form an electrostatic latent image corresponding to target image information. The image exposure light 4 is intensity-modulated light corresponding to a time-series electric digital image signal of target image information, which is output from an exposure means such as slit exposure or laser beam scanning exposure, for example.

The electrostatic latent image formed on the surface of the electrophotographic photoreceptor 1 is developed with toner contained in the developing means 5 (regular development or reversal development), and a toner image is formed on the surface of the electrophotographic photoreceptor 1. be done. The toner image formed on the surface of the electrophotographic photoreceptor 1 is transferred onto a transfer material 7 by a transfer means 6. At this time, a bias voltage having a polarity opposite to the charge held by the toner is applied to the transfer means 6 from a bias power source (not shown). Further, when the transfer material 7 is paper, the transfer material 7 is taken out from a paper feed section (not shown) and is placed between the electrophotographic photoreceptor 1 and the transfer means 6 in synchronization with the rotation of the electrophotographic photoreceptor 1. will be delivered.

The transfer material 7 to which the toner image has been transferred from the electrophotographic photoreceptor 1 is separated from the surface of the electrophotographic photoreceptor 1 and then conveyed to the fixing means 8 where the toner image is fixed, thereby forming an image. Printed out as an object (print, copy) outside the electrophotographic device.

After the toner image has been transferred to the transfer material 7, the surface of the electrophotographic photoreceptor 1 is cleaned by the cleaning means 9 by removing deposits such as toner (untransferred toner). With the cleaner-less system that has been developed in recent years, it is also possible to directly remove the residual toner after transfer using a developing device or the like. Further, the surface of the electrophotographic photoreceptor 1 is subjected to static elimination treatment by pre-exposure light 10 from a pre-exposure means (not shown), and then used for repeated image formation. Note that if the charging means 3 is a contact charging means using a charging roller or the like, the pre-exposure means is not necessarily required.

In the present invention, a process cartridge is formed by housing a plurality of components, such as the electrophotographic photoreceptor 1, charging means 3, developing means 5, and cleaning means 9, in a container and integrally supporting them. . This process cartridge can be configured to be detachable from the main body of the electrophotographic apparatus. For example, at least one selected from the charging means 3, the developing means 5, and the cleaning means 9 is integrally supported with the electrophotographic photoreceptor 1 to form a cartridge. The process cartridge 11 can be detachably attached to the electrophotographic apparatus main body using a guide means 12 such as a rail of the electrophotographic apparatus main body.

When the electrophotographic apparatus is a copying machine or a printer, the exposure light 4 may be reflected light or transmitted light from a document. Alternatively, the light may be light emitted by reading a document with a sensor, converting it into a signal, and scanning a laser beam, driving an LED array, or driving a liquid crystal shutter array in accordance with the signal.

The electrophotographic photoreceptor 1 of the present invention can be widely applied to electrophotographic application fields such as laser beam printers, CRT printers, LED printers, FAXs, liquid crystal printers, and laser plate making.

The present invention will be explained in more detail below by giving specific examples. "Parts" described below mean "parts by mass." However, the present invention is not limited to these. The film thickness of each layer of the electrophotographic photoreceptors of Examples and Comparative Examples was determined by a method using an eddy current film thickness meter (Fischerscope, manufactured by Fischer Instruments Inc.) or a method using a spectral interference film thickness meter (C-13027-11). (manufactured by Hamamatsu Photonics) or by converting specific gravity from mass per unit area.

[Example 1]
[Example of photoconductor creation]
(Support)
As the support (conductive support), a machined cylindrical aluminum cylinder (JIS-A3003, aluminum alloy, outer diameter 30 mm, length 357.5 mm, wall thickness 0.7 mm) was used. Ultrasonic cleaning was performed in a cleaning solution containing pure water with a detergent (product name: Chemicol CT, manufactured by Joban Chemical Co., Ltd.), and then after rinsing off the cleaning solution, further ultrasonic cleaning was performed in pure water. , was degreased and used as a support.

(first layer)
23 parts of butyral resin (trade name: BM-1, manufactured by Sekisui Chemical Co., Ltd.) as a polyol resin and 23 parts of blocked isocyanate resin (trade name: TPA-B80E, 80% solution, manufactured by Asahi Kasei Corporation) were mixed with methyl ethyl ketone. : A solution was obtained by dissolving 1-butanol in 110 parts of a solvent mixed at a ratio of 35:65.
50 parts of a mixture of the perinone compound represented by the formula (1-1) and the perinone compound represented by the formula (2-1) in a ratio of 1:1 was added to the obtained mixture, and Bragg in CuKα characteristic X-ray diffraction was added. Crystal form with peaks at angles (2θ±0.2°) of 7.5°, 9.9°, 12.5°, 16.3°, 18.6°, 25.1° and 28.3° 5 parts of hydroxygallium phthalocyanine (described as HOGa-Pc in the table) crystals were added thereto, glass beads with a diameter of 0.8 mm were added, and the mixture was stirred in a paint shaker for 5 hours to obtain a coating solution for the first layer.
The obtained coating solution was applied onto the above support by dip coating to form a coating film, and the coating film was dried and cured at 160° C. for 35 minutes to form a first layer having a film thickness of 15.2 μm. .

(second layer)
Bragg angles (2θ±0.2°) of 7.5°, 9.9°, 12.5°, 16.3°, 18.6°, 25.1° and 28.3 in CuKα characteristic X-ray diffraction A crystalline hydroxygallium phthalocyanine crystal having a peak at ° was prepared. 10 parts of this hydroxygallium phthalocyanine crystal, 5 parts of polyvinyl butyral (trade name: Eslec BX-1, manufactured by Sekisui Chemical Co., Ltd.) and 250 parts of cyclohexanone were placed in a sand mill using glass beads with a diameter of 1 mm, and dispersed for 2 hours. Processed. Next, 250 parts of ethyl acetate was added to this to prepare a second layer coating solution.
This coating solution was applied onto the first layer by dip coating, and the resulting coating film was dried at 95° C. for 10 minutes to form a second layer having a thickness of 0.17 μm.

並びに、下記式（８）及び（９）で示される繰り返し構造単位を５／５のモル比で有している、重量平均分子量（Ｍｗ）が１００，０００であるポリエステル樹脂（Ｐ１）１０部を、

ジメトキシメタン４０部及びクロロベンゼン６０部の混合溶剤に溶解させることによって、電荷輸送層用塗布液を調製した。
この電荷輸送層用塗布液を、第二の層上に浸漬塗布し、得られた塗膜を４０分間１２０℃で乾燥させることによって、膜厚が１５μｍの電荷輸送層を形成した。 (charge transport layer)
Next, 8 parts of an amine compound (hole transport substance) represented by the following structural formula (7),

Also, 10 parts of a polyester resin (P1) having a weight average molecular weight (Mw) of 100,000 and having repeating structural units represented by the following formulas (8) and (9) at a molar ratio of 5/5. ,

A coating solution for a charge transport layer was prepared by dissolving it in a mixed solvent of 40 parts of dimethoxymethane and 60 parts of chlorobenzene.
This charge transport layer coating liquid was applied onto the second layer by dip coating, and the resulting coating film was dried at 120° C. for 40 minutes to form a charge transport layer having a thickness of 15 μm.

[Evaluation of photoreceptor]
The electrophotographic photoreceptor produced above was evaluated for graininess and potential fluctuation under a normal temperature and normal humidity environment (temperature 23° C., relative humidity 50%). The results are shown in Table 5.

(Evaluation of dark attenuation)
In this evaluation example, an experimental apparatus was prepared in which a charging roller to which a voltage obtained by superimposing a DC voltage and an AC voltage was applied was brought into contact with an electrophotographic photoreceptor as a charging means. Then, when uniformly charged to -900V, the surface potential (Vd0.1) 0.1 seconds after charging and the surface potential (Vd1.0) 1.0 seconds after charging were measured. The ratio of Vd1.0 to .1 (Vdd) was defined as dark decay. The larger the value of Vdd, the higher the dark decay suppression effect.
Judgment was made using the following evaluation criteria A to C based on the determined Vdd. Note that if the evaluation result is B or higher, it can be determined that the effects of the present invention have been obtained.
The evaluation results are shown in Table 5.
A: Vdd is 0.90 or more B: Vdd is 0.85 or more and less than 0.90 C: Vdd is less than 0.85

(Evaluation of graininess)
Graininess was evaluated at the same charging potential as the one at which the dark decay evaluation was performed. Under the same conditions as the charging potential setting used for the dark decay evaluation, the development contrast for the charging potential was adjusted so that the output results of all Examples were halftone images of the same density, and analog output was performed without exposure. Five points within the plane of the output image were observed using an optical microscope, and halftone density unevenness was sensory evaluated using the following level.
Ranks A, B, C, and D are levels at which the effects of the invention are obtained in terms of graininess, and among them, rank A is judged to be an excellent level. On the other hand, rank E is a level at which the effects of the invention are not obtained.
A: No halftone density unevenness was observed at all five observation points.
B: Halftone density unevenness is slightly visible at some of the five observation points.
C: Halftone density unevenness is slightly visible at all five observation points.
D: Halftone density unevenness is clearly visible at some of the five observation points, but at a level that is not noticeable.
E: Halftone density unevenness is clearly visible at all five observation points.

(Evaluation of potential fluctuation during repeated use)
In this evaluation example, the electrophotographic photoreceptor was attached to a multifunction device imageRUNNER ADVANCE C5255 (registered trademark) manufactured by Canon Inc. and evaluated.
Specifically, the above evaluation apparatus was installed in an environment of normal temperature and normal humidity (23° C./50% RH). The produced electrophotographic photoreceptor was attached to a process cartridge, and the process cartridge was attached to a cartridge station of a copying machine and evaluated.
A developing cartridge equipped with an electrophotographic photoreceptor was attached to the above-mentioned evaluation apparatus, and the photoreceptor was repeatedly used by passing 10,000 sheets. Character images in a single color with a printing rate of 1% were repeatedly formed on 10,000 sheets of A4 size plain paper.
The initial bright area potential at this time is compared with the bright area potential after 10,000 images have been repeatedly formed, and this is taken as the value of potential fluctuation (ΔVl). After passing 10,000 sheets, the cartridge was left for 5 minutes, the developing cartridge was replaced with a potential measuring device, and the bright area potential (Vlb) and dark area potential (Vdb) after repeated use were measured.
The difference between the bright area potential and the initial bright area potential after repeated use is the amount of bright area potential variation (ΔVl=|Vlb|-|Vla|), and the difference between the dark area potential and the initial dark area potential after repeated use is the dark area potential variation. It was determined as the amount (ΔVd=|Vdb|−|Vda|) and evaluated according to the following evaluation rank. In the present invention, ranks A, B, C, and D are levels that pose no problem in actual use as potential fluctuations, and among them, rank A is judged to be an excellent level. On the other hand, rank E is considered to be at a level where there are harmful effects in actual use.
A: When the change in bright potential and dark potential is within 5V B: When the change in bright potential and dark potential is greater than 5V and within 10V C: When the change in bright potential and dark potential is greater than 10V and within 20V Case D: When the change in bright area potential and dark area potential is greater than 20V and within 30V E: When the change in bright area potential and dark area potential is greater than 30V

[Examples 2 to 12]
A photoreceptor was produced in the same manner as in Example 1, except that the material composition of the first layer was made as shown in Table 1, and the material composition of the second layer was made as shown in Table 2. The evaluation was carried out in the same way. The evaluation results are shown in Table 5.

[Example 13]
In Example 1, the hydroxygallium phthalocyanine pigments (described as HOGa-Pc in Tables 1 and 2) of the first layer and the second layer were mixed with a Bragg angle (2θ±0.2°) in CuKα characteristic X-ray diffraction. Examples except that the pigment was changed to a crystalline chlorogallium phthalocyanine pigment (described as ClGa-Pc in Tables 1 and 2) having strong peaks at 7.4°, 16.6°, 25.5°, and 28.2°. A photoreceptor was prepared in the same manner as in Example 1, and evaluated in the same manner as in Example 1. The evaluation results are shown in Table 5.

[Example 14]
In Example 1, the hydroxygallium phthalocyanine pigment of the second layer was used at Bragg angles (2θ±0.2°) of 7.4°, 16.6°, 25.5°, and 28.0° in CuKα characteristic X-ray diffraction. A photoreceptor was prepared in the same manner as in Example 1, except that a crystalline chlorogallium phthalocyanine pigment having a strong peak at 2° was used, and evaluation was performed in the same manner as in Example 1. The evaluation results are shown in Table 5.

[Example 15]
The same procedure as in Example 1 was carried out except that the perinone compound in the first layer was changed to a mixture of a perinone compound represented by formula (1-8) and a perinone compound represented by formula (2-8) at a ratio of 1:1. A photoreceptor was prepared in the same manner as in Example 1, and evaluated in the same manner as in Example 1. The evaluation results are shown in Table 5.

[Example 16]
The same procedure was carried out as in Example 1 except that the perinone compound in the first layer was changed to a mixture of a perinone compound represented by formula (1-12) and a perinone compound represented by formula (2-12) at a ratio of 1:1. A photoreceptor was prepared in the same manner as in Example 1, and evaluated in the same manner as in Example 1. The evaluation results are shown in Table 5.

[Example 17]
The same procedure was carried out as in Example 1 except that the perinone compound in the first layer was changed to a mixture of a perinone compound represented by formula (1-13) and a perinone compound represented by formula (2-13) at a ratio of 1:1. A photoreceptor was prepared in the same manner as in Example 1, and evaluated in the same manner as in Example 1. The evaluation results are shown in Table 5.

[Example 18]
In Example 1, a photoreceptor was prepared and evaluated in the same manner as in Example 1, except that the configuration of the first layer was changed as follows.

(first layer)
50 parts of a mixture of the perinone compound represented by formula (1-1) and the perinone compound represented by formula (2-1) in a ratio of 1:1, polyvinyl butyral (trade name: Eslec BX-1, Sekisui Chemical Co., Ltd.) (manufactured by Kogyo Co., Ltd.) 45 parts, Bragg angle (2θ ± 0.2°) of 7.5°, 9.9°, 12.5°, 16.3°, 18.6° in CuKα characteristic X-ray diffraction Glass beads having a diameter of 0.8 mm were added to 5 parts of hydroxygallium phthalocyanine crystals having peaks at , 25.1° and 28.3° and 150 parts of cyclohexanone, and the mixture was stirred in a paint shaker for 4 hours. Next, 150 parts of ethyl acetate was added to this to prepare a first layer coating solution.
This coating solution was applied onto a support by dip coating, and the resulting coating film was dried at 95° C. for 20 minutes to form a first layer having a thickness of 5.2 μm. The evaluation results are shown in Table 5.

[Example 19]
In Example 1, a photoreceptor was prepared and evaluated in the same manner as in Example 1, except that the configuration of the first layer was changed as follows.

(first layer)
50 parts of a mixture of the perinone compound represented by formula (1-1) and the perinone compound represented by formula (2-1) in a ratio of 1:1, copolymerized nylon resin (trade name: Amilan CM8000, Toray (trade name: Amilan CM8000), Co., Ltd.) 50 parts, Bragg angles (2θ ± 0.2°) of 7.5°, 9.9°, 12.5°, 16.3°, 18.6°, 25 in CuKα characteristic X-ray diffraction. 5 parts of hydroxygallium phthalocyanine crystals having peaks at 1° and 28.3° were dispersed in a mixed solution of 330 parts of methanol and 170 parts of butanol, and glass beads with a diameter of 0.8 mm were added to the solution. The mixture was stirred in a paint shaker for 4 hours to prepare a coating solution for the first layer.
This coating solution was applied to a support by dip coating, and the resulting coating film was heated at 100° C. for 20 minutes to form a first layer having a thickness of 5.0 μm. The evaluation results are shown in Table 5.

[Comparative example 1]
In Example 1, a photoreceptor was produced in the same manner as in Example 1, except that the material composition of the first layer was made as shown in Table 3, and the material composition of the second layer was made as shown in Table 4. and evaluated it. The evaluation results are shown in Table 5.

[Comparative example 2]
A photoreceptor was prepared in the same manner as in Comparative Example 1, except that the perinone compound in the first layer was changed to a perylene pigment represented by formula (10), and the material composition was changed to the one shown in Table 3. and evaluated it. The evaluation results are shown in Table 5.

[Comparative example 3]
In Comparative Example 1, the photoreceptor was prepared in the same manner as in Comparative Example 1, except that the perinone compound in the first layer was changed to an anthrone pigment represented by formula (11), and the material composition was changed to the one shown in Table 3. Created and evaluated. The evaluation results are shown in Table 5.

[Comparative example 4]
In Example 1, the hydroxygallium phthalocyanine pigments of the first layer and the second layer had Bragg angles (2θ±0.2°) of 9.0°, 14.2°, and 23.9 in CuKα characteristic X-ray diffraction. A photoreceptor was prepared and evaluated in the same manner as in Example 1, except that the pigment was changed to a crystalline oxytitanium phthalocyanine pigment (described as TiO-Pc in Tables 3 and 4) that has strong peaks at 27.1° and 27.1°. Ta. The evaluation results are shown in Table 5.

[Comparative example 5]
In Comparative Example 4, a photoreceptor was prepared and evaluated in the same manner as in Comparative Example 4, except that the perinone compound in the first layer was changed to a perylene pigment represented by formula (10). The evaluation results are shown in Table 5.

[Comparative example 6]
In Comparative Example 4, a photoreceptor was prepared and evaluated in the same manner as in Comparative Example 4, except that the perinone compound in the first layer was changed to an anthrone pigment represented by formula (11). The evaluation results are shown in Table 5.

[Comparative Example 7]
In Example 1, a photoreceptor was produced and evaluated in the same manner as in Example 1, except that the configurations of the first layer and the second layer were changed as follows. The evaluation results are shown in Table 5.

(first layer)
Dispersed in a mixed liquid of 50 parts of perylene pigment represented by formula (11), 50 parts of copolymerized nylon resin (trade name: Amilan CM8000, manufactured by Toray Industries, Inc.), 330 parts of methanol and 170 parts of butanol, and in the liquid, Glass beads with a diameter of 0.8 mm were added and stirred for 4 hours using a paint shaker to prepare a coating solution for the first layer.
This coating solution was applied to a support by dip coating, and the resulting coating film was heated at 100° C. for 20 minutes to form a first layer having a thickness of 5.4 μm.

(second layer)
10 parts of crystalline oxytitanium phthalocyanine pigment having strong peaks at Bragg angles (2θ±0.2°) of 9.0°, 14.2°, 23.9° and 27.1° in CuKα characteristic X-ray diffraction , 5 parts of polyvinyl butyral (trade name: S-LEC BX-1, manufactured by Sekisui Chemical Co., Ltd.) and 250 parts of cyclohexanone were added with glass beads having a diameter of 0.8 mm and stirred for 4 hours in a paint shaker. Next, 250 parts of ethyl acetate was added to this to prepare a second layer coating solution.
This coating liquid was applied onto the first layer by dip coating, and the resulting coating film was dried at 95° C. for 10 minutes to form a second layer having a thickness of 0.29 μm.

（式（１）中、Ｒ^１１～Ｒ^１８及び式（２）中、Ｒ^２１～Ｒ^２８は、それぞれ独立に、水素原子、ハロゲン原子、置換若しくは無置換のアルキル基、置換若しくは無置換のアリール基、置換若しくは無置換のアリールオキシ基、置換若しくは無置換のアルコキシカルボニル基を示す。Ｒ^１１～Ｒ^１４、Ｒ^１５～Ｒ^１８、Ｒ^２１～Ｒ^２４及びＲ^２５～Ｒ^２８の各群の中で隣り合う基同士は連結して共同して環を形成してもよい。）
［構成２］
前記第一の層中の前記ペリノン化合物の含有量が、前記第一の層中のガリウムフタロシアニン顔料の含有量に対して５０質量％以上１０００質量％以下であり、
前記第二の層が前記ペリノン化合物を含有しない、あるいは、前記第二の層が前記ペリノン化合物を含有し、かつ前記第二の層中の前記ペリノン化合物の含有量が前記第二の層中の前記ガリウムフタロシアニン顔料の含有量に対して１質量％以下である、
構成１に記載の電子写真感光体。
［構成３］
前記第一の層中の前記ガリウムフタロシアニン顔料の含有量が、前記第一の層の全質量に対して５質量％以上５０質量％以下であり、
前記第二の層中の前記ガリウムフタロシアニン顔料の含有量が、前記第二の層の全質量に対して５０質量％以上７５質量％以下である、
請求項１又は２に記載の電子写真感光体。
［構成４］
前記第一の層の膜厚が、２μｍ以上２０μｍ以下であり、前記第二の層の膜厚が、０．１μｍ以上０．５μｍ以下である構成１～３のいずれか一の構成に記載の電子写真感光体。
［構成５］
前記ガリウムフタロシアニン顔料が、クロロガリウムフタロシアニン顔料及び
ヒドロキシガリウムフタロシアニン顔料からなる群から選択される少なくとも一種である構成１～４のいずれか一の構成に記載の電子写真感光体。
［構成６］
前記第一の層が、前記ペリノン化合物として下記式（３）で表されるペリノン化合物及び下記式（４）で表されるペリノン化合物からなる群より選択される少なくとも一種のペリノン化合物で示される化合物を含有する構成１～５のいずれか一の構成に記載の電子写真感光体。

（式（３）中、Ｒ^３１及びＲ^３２、並びに式（４）中のＲ^４１及びＲ^４２は、それぞれ独立に、炭素数が３以上１０以下の分岐したアルキル基を示す。）
［構成７］
前記第一の層が、前記ペリノン化合物として下記式（５）で示されるペリノン化合物及び下記式（６）で示されるペリノン化合物からなる群より選択される少なくとも一種のペリノン化合物で示される化合物を含有する構成１～６のいずれか一の構成に記載の電子写真感光体。

（式（５）中のＲ^５１～Ｒ^５６、及び式（６）中のＲ^６１～Ｒ^６６はそれぞれ独立に、メチル基、エチル基、又はプロピル基を示す。
［構成８］
前記第一の層が、前記ペリノン化合物及び前記ガリウムフタロシアニン顔料を
含む塗布液の塗膜を乾燥及び／又は硬化させることによって形成された層である
構成１～７のいずれか一の構成に記載の電子写真感光体。
［構成９］
構成１～８のいずれか一の構成に記載の電子写真感光体と、帯電手段、現像手段、及びクリーニング手段からなる群より選択される少なくとも１つの手段と、を一体に支持し、電子写真装置の本体に着脱自在であるプロセスカートリッジ。
［構成１０］
構成１～８のいずれか一の構成に記載の電子写真感光体、並びに、帯電手段、露光手段、現像手段、及び転写手段を有する電子写真装置。
［方法１］
支持体、第一の層、第二の層及び電荷輸送層をこの順に有する電子写真感光体を製造する電子写真感光体の製造方法であって、
該製造方法が、
結着樹脂及び／又は結着樹脂用モノマー、ガリウムフタロシアニン顔料、並びに、下記式（１）で示される化合物及び下記式（２）で示される化合物からなる群より選択される少なくとも１種のペリノン化合物を含有する第一の層用塗布液を調製する工程、
該第一の層用塗布液の塗膜を前記支持体上に形成し、該第一の層用塗布液の該塗膜を乾燥及び／又は硬化させることによって前記支持体上に前記第一の層を形成する工程、
結着樹脂及び／又は結着樹脂用モノマー、並びに、ガリウムフタロシアニン顔料を含有する第二の層用塗布液を調製する工程、
該第二の層用塗布液の塗膜を前記第一の層上に形成し、該第二の層用塗布液の該塗膜を乾燥及び／又は硬化させることによって該第一の層上に該第二の層を形成する工程、並びに、
該第二の層上に前記電荷輸送層を形成する工程
を有することを特徴とする電子写真感光体の製造方法。

（式（１）中、Ｒ^１１～Ｒ^１８、は、及び、式（２）中、Ｒ^２１～Ｒ^２８は、それぞれ独立に、水素原子、ハロゲン原子、置換若しくは無置換のアルキル基、置換若しくは無置換のアリール基、置換若しくは無置換のアリールオキシ基、置換若しくは無置換のアルコキシカルボニル基を示す。Ｒ^１１～Ｒ^１４、Ｒ^１５～Ｒ^１８、Ｒ^２１～Ｒ^２４及びＲ^２５～Ｒ^２８の各群の中で隣り合う基同士は連結して共同して環を形成してもよい。） The disclosure of this embodiment includes the following configuration and method.
[Configuration 1]
An electrophotographic photoreceptor comprising a support, a first layer, a second layer, and a charge transport layer in this order,
The first layer includes a binder resin, a gallium phthalocyanine pigment, and at least one type of perinone compound selected from the group consisting of a perinone compound represented by the following formula (1) and a perinone compound represented by the following formula (2). Contains a perinone compound,
An electrophotographic photoreceptor, wherein the second layer contains a binder resin and a gallium phthalocyanine pigment.

(In formula (1), R ¹¹ to R ¹⁸ and in formula (2), R ²¹ to R ²⁸ are each independently a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, substituted or unsubstituted aryloxy group, substituted or unsubstituted alkoxycarbonyl group.In each group of ^{R 11} to R ¹⁴ , R ¹⁵ to R ¹⁸ , R ²¹ to R ²⁴ and R ²⁵ to R ²⁸ Adjacent groups may be linked together to form a ring.)
[Configuration 2]
The content of the perinone compound in the first layer is 50% by mass or more and 1000% by mass or less with respect to the content of the gallium phthalocyanine pigment in the first layer,
The second layer does not contain the perinone compound, or the second layer contains the perinone compound, and the content of the perinone compound in the second layer is lower than that in the second layer. The content of the gallium phthalocyanine pigment is 1% by mass or less,
The electrophotographic photoreceptor according to configuration 1.
[Configuration 3]
The content of the gallium phthalocyanine pigment in the first layer is 5% by mass or more and 50% by mass or less based on the total mass of the first layer,
The content of the gallium phthalocyanine pigment in the second layer is 50% by mass or more and 75% by mass or less based on the total mass of the second layer.
The electrophotographic photoreceptor according to claim 1 or 2.
[Configuration 4]
According to any one of configurations 1 to 3, the first layer has a thickness of 2 μm or more and 20 μm or less, and the second layer has a thickness of 0.1 μm or more and 0.5 μm or less. Electrophotographic photoreceptor.
[Configuration 5]
The electrophotographic photoreceptor according to any one of configurations 1 to 4, wherein the gallium phthalocyanine pigment is at least one selected from the group consisting of chlorogallium phthalocyanine pigments and hydroxygallium phthalocyanine pigments.
[Configuration 6]
The first layer is a compound represented by at least one perinone compound selected from the group consisting of a perinone compound represented by the following formula (3) and a perinone compound represented by the following formula (4) as the perinone compound. The electrophotographic photoreceptor according to any one of configurations 1 to 5, comprising:

(R ³¹ and R ³² in formula (3), and R ⁴¹ and R ⁴² in formula (4) each independently represent a branched alkyl group having 3 or more and 10 or less carbon atoms.)
[Configuration 7]
The first layer contains, as the perinone compound, at least one perinone compound selected from the group consisting of a perinone compound represented by the following formula (5) and a perinone compound represented by the following formula (6). The electrophotographic photoreceptor according to any one of configurations 1 to 6.

(R ⁵¹ to R ⁵⁶ in formula (5) and R ⁶¹ to R ⁶⁶ in formula (6) each independently represent a methyl group, an ethyl group, or a propyl group.
[Configuration 8]
According to any one of configurations 1 to 7, the first layer is a layer formed by drying and/or curing a coating film of a coating solution containing the perinone compound and the gallium phthalocyanine pigment. Electrophotographic photoreceptor.
[Configuration 9]
An electrophotographic apparatus, which integrally supports the electrophotographic photoreceptor according to any one of structures 1 to 8 and at least one means selected from the group consisting of charging means, developing means, and cleaning means, A process cartridge that can be attached to and detached from the main body.
[Configuration 10]
An electrophotographic apparatus comprising the electrophotographic photoreceptor according to any one of structures 1 to 8, a charging means, an exposure means, a developing means, and a transfer means.
[Method 1]
A method for producing an electrophotographic photoreceptor comprising a support, a first layer, a second layer, and a charge transport layer in this order, the method comprising:
The manufacturing method includes:
A binder resin and/or a monomer for a binder resin, a gallium phthalocyanine pigment, and at least one perinone compound selected from the group consisting of a compound represented by the following formula (1) and a compound represented by the following formula (2). a step of preparing a first layer coating solution containing;
A coating film of the first layer coating liquid is formed on the support, and the coating film of the first layer coating liquid is dried and/or cured to form a coating film of the first layer coating liquid on the support. a step of forming a layer;
preparing a second layer coating solution containing a binder resin and/or a monomer for the binder resin, and a gallium phthalocyanine pigment;
A coating film of the coating liquid for the second layer is formed on the first layer, and the coating film of the coating liquid for the second layer is dried and/or cured to form a coating film on the first layer. forming the second layer, and
A method for manufacturing an electrophotographic photoreceptor, comprising the step of forming the charge transport layer on the second layer.

(In formula (1), R ¹¹ to R ¹⁸ are, and in formula (2), R ²¹ to R ²⁸ are each independently a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkyl group, It represents ^an unsubstituted aryl group, ^{a substituted or} unsubstituted aryloxy group, ^a substituted or ^{unsubstituted} alkoxycarbonyl ^{group .} Adjacent groups within each group may be linked together to form a ring.)

101: Support 102: Undercoat layer 103: First layer 104: Second layer 105: Charge transport layer 1: Electrophotographic photoreceptor 2: Shaft 3: Charging means 4: Image exposure light 5: Developing means 6: Transfer means 7: Transfer material 8: Image fixing means 9: Cleaning means 10: Pre-exposure light 11: Process cartridge 12: Guide means

Claims (11)

An electrophotographic photoreceptor comprising a support, a first layer, a second layer, and a charge transport layer in this order,
The first layer includes a binder resin, a gallium phthalocyanine pigment, and at least one type of perinone compound selected from the group consisting of a perinone compound represented by the following formula (1) and a perinone compound represented by the following formula (2). Contains a perinone compound,
The second layer contains a binder resin and a gallium phthalocyanine pigment.
An electrophotographic photoreceptor characterized by:

(In formula (1), R ¹¹ to R ¹⁸ and in formula (2), R ²¹ to R ²⁸ are each independently a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, substituted or unsubstituted aryloxy group, substituted or unsubstituted alkoxycarbonyl group.In each group of ^{R 11} to R ¹⁴ , R ¹⁵ to R ¹⁸ , R ²¹ to R ²⁴ and R ²⁵ to R ²⁸ Adjacent groups may be linked together to form a ring.) The content of the perinone compound in the first layer is 50% by mass or more and 1000% by mass or less with respect to the content of the gallium phthalocyanine pigment in the first layer,
The second layer does not contain the perinone compound, or the second layer contains the perinone compound, and the content of the perinone compound in the second layer is lower than that in the second layer. The content of the gallium phthalocyanine pigment is 1% by mass or less,
The electrophotographic photoreceptor according to claim 1. The content of the gallium phthalocyanine pigment in the first layer is 5% by mass or more and 50% by mass or less based on the total mass of the first layer,
The content of the gallium phthalocyanine pigment in the second layer is 50% by mass or more and 75% by mass or less based on the total mass of the second layer.
The electrophotographic photoreceptor according to claim 1. The thickness of the first layer is 2 μm or more and 20 μm or less,
The thickness of the second layer is 0.1 μm or more and 0.5 μm or less,
The electrophotographic photoreceptor according to claim 1. The electrophotographic photoreceptor according to claim 1, wherein the gallium phthalocyanine pigment is at least one selected from the group consisting of chlorogallium phthalocyanine pigments and hydroxygallium phthalocyanine pigments. The first layer is represented by at least one perinone compound selected from the group consisting of a perinone compound represented by the following formula (3) and a perinone compound represented by the following formula (4), as the perinone compound. The electrophotographic photoreceptor according to claim 1, containing a compound.

(R ³¹ and R ³² in formula (3), and R ⁴¹ and R ⁴² in formula (4) each independently represent a branched alkyl group having 3 or more and 10 or less carbon atoms.) The first layer contains, as the perinone compound, at least one perinone compound selected from the group consisting of a perinone compound represented by the following formula (5) and a perinone compound represented by the following formula (6). The electrophotographic photoreceptor according to claim 1, comprising:

(R ⁵¹ to R ⁵⁶ in formula (5) and R ⁶¹ to R ⁶⁶ in formula (6) each independently represent a methyl group, an ethyl group, or a propyl group.) The electrophotographic photoreceptor according to claim 1, wherein the first layer is a layer formed by drying and/or curing a coating film of a coating solution containing the perinone compound and the gallium phthalocyanine pigment. The electrophotographic photoreceptor according to any one of claims 1 to 8 and at least one means selected from the group consisting of charging means, developing means, and cleaning means are integrally supported, and A process cartridge that can be attached to and detached from the main body. An electrophotographic apparatus comprising the electrophotographic photoreceptor according to any one of claims 1 to 8, charging means, exposure means, developing means, and transfer means. A method for producing an electrophotographic photoreceptor comprising a support, a first layer, a second layer, and a charge transport layer in this order, the method comprising:
The manufacturing method includes:
A binder resin and/or a monomer for a binder resin, a gallium phthalocyanine pigment, and at least one perinone compound selected from the group consisting of a compound represented by the following formula (1) and a compound represented by the following formula (2). a step of preparing a first layer coating solution containing;
A coating film of the first layer coating solution is formed on the support, and the coating film of the first layer coating solution is dried and/or cured to form a coating film of the first layer coating solution on the support. a step of forming a layer;
preparing a second layer coating solution containing a binder resin and/or a monomer for the binder resin, and a gallium phthalocyanine pigment;
A coating film of the coating liquid for the second layer is formed on the first layer, and the coating film of the coating liquid for the second layer is dried and/or cured to form a coating film on the first layer. forming the second layer, and
A method for manufacturing an electrophotographic photoreceptor, comprising the step of forming the charge transport layer on the second layer.

(In formula (1), R ¹¹ to R ¹⁸ are, and in formula (2), R ²¹ to R ²⁸ are each independently a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkyl group, It represents ^an unsubstituted aryl group, ^{a substituted or} unsubstituted aryloxy group, ^a substituted or ^{unsubstituted} alkoxycarbonyl ^{group .} Adjacent groups within each group may be linked together to form a ring.)

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