JP2019095679A - Process cartridge and electrophotographic device - Google Patents

Abstract

To provide a process cartridge that achieves improvement in developing property based on toner, and causes no falling of an image quality due to fogging over a long period.SOLUTION: A process cartridge has: an electrification member; an electrophotographic photoreceptor that is contact-electrified by the electrification member; a developing member that forms a toner image developed by toner on the electrophotographic photoreceptor; and a transfer member that transfers the toner image on the electrophotographic photoreceptor to a transfer material. The toner contains: a toner particle that has binder resin and a charge control agent; and an external additive. The charge control agent has azo group chromium complex, and a content of the external additive is equal to or more than 1.7 mass% with respect to a content of the toner particle. The electrophotographic photoreceptor has a front surface layer, and Martens hardness of the front surface layer is equal to or more than 245 N/mm.SELECTED DRAWING: None

Description

  The present invention relates to a process cartridge and an electrophotographic apparatus.

In the electrophotographic process, in recent years, demands for higher recording speed and higher image quality have been increasing. Correspondingly, there is known a method using a toner charge control agent having excellent charge control performance, specifically, a toner containing a charge control agent of an azo group-containing chromium complex as a toner (Patent Document 1 1, 2). By using the charge control agent, high-quality images can be stably obtained over a long period of time without causing fog even in high-speed recording and regardless of the use environment.
However, when the toners described in Patent Documents 1 and 2 are used, although the fog is improved, they are not sufficient, and the demand for stable high image quality in long-term use, which is required in recent years, has not been reached.
In order to obtain long-term stable developability, an improvement can be achieved by adding a large amount of external additive, but in this case contamination of the electrophotographic photosensitive member with the external additive occurs, and likewise in long-term use. It is difficult to achieve stable high image quality requirements.

JP 2008-52306 A JP, 2010-120854, A

  An object of the present invention is to provide a process cartridge which improves the developability with toner and does not cause deterioration in image quality due to fog over a long period of time.

The above object is achieved by the present invention described below. That is, the process cartridge according to the present invention comprises a charging member, an electrophotographic photosensitive member contact-charged by the charging member, a developing member for developing a toner image on the electrophotographic photosensitive member to form a toner image, A process cartridge comprising: a transfer member for transferring the toner image on an electrophotographic photosensitive member to a transfer material, wherein the toner comprises toner particles having a binder resin and a charge control agent, and an external additive. The charge control agent has an azo group-containing chromium complex, and the content of the external additive is 1.7% by mass or more based on the content of the toner particles, and the electrophotographic photosensitive member has a surface layer And the Martens hardness of the surface layer is 245 N / mm ² or more.

  According to the present invention, it is possible to provide a process cartridge which does not cause deterioration in image quality due to fog over a long period of time.

FIG. 1 is a schematic configuration diagram of an example of an electrophotographic apparatus.

Hereinafter, the present invention will be described in detail by way of preferred embodiments. The present invention comprises a charging member, an electrophotographic photosensitive member contact-charged by the charging member, a developing member for developing a toner image on the electrophotographic photosensitive member to form a toner image, and the electrophotographic photosensitive member. A transfer member for transferring the toner image to a transfer material, wherein the toner comprises toner particles having a binder resin and a charge control agent, and an external additive, the charge control agent Has an azo group-containing chromium complex, the content of the external additive is 1.7% by mass or more based on the content of the toner particles, and the electrophotographic photosensitive member has a surface layer, The process cartridge is characterized in that the Martens hardness of the surface layer is 245 N / mm ² or more.

  The inventors of the present invention have found that, although a charge control agent having an azo group-containing chromium complex is effective as a toner for obtaining high developability, it has not been sufficient considering long-term use required in recent years. In order to cope with this, by containing the external additive at 1.7% by mass or more with respect to the content of toner particles, the triboelectric charge imparting ability was improved, and an attempt was made to maintain the developability for a long time. As a result, although stable developability over a long period of time can be easily obtained, in this case the detachment of the external additive from the toner tends to increase, and the external additive of the toner contaminates the surface of the electrophotographic photosensitive member, I have a problem with fog. Although an attempt was made to firmly fix the external additive in order to prevent the detachment of the external additive from the toner, in this case the external additive was embedded in the toner particles, and rather a decrease in the developability was observed.

Therefore, the present inventors paid attention to the Martens hardness of the surface layer of the electrophotographic photosensitive member as a method of preventing the contamination by the external additive released from the toner. And, it was found that when the Martens hardness of the surface of the electrophotographic photosensitive member is 245 N / mm ² or more, the problem of fog does not occur for a long time. The present inventors speculate about this as follows.

  Focusing on the transfer step of the electrophotographic process, when the toner gets on the electrophotographic photosensitive member in the developing step and then is transferred onto the transfer belt or paper, rubbing occurs between the electrophotographic photosensitive member and the toner. Then, at the time of this rubbing, the external additive is detached from the toner although this is slight. The released external additive is collected by the cleaning member or other equivalent scraping member. However, in the case of a toner in which the amount of external additive is 1.7% by mass or more with respect to the content of toner particles, accumulation of the separated external additive proceeds on the surface of the electrophotographic photosensitive member for long-term stability . As a result, it has been found that, in long-term use, contamination of the electrophotographic photosensitive member with the external additive is caused to reduce the charge imparting ability to the toner.

  Therefore, the present inventors have considered that the external additive is fixed to the toner particles so that the external additive is not detached from the toner when rubbing occurs between the electrophotographic photosensitive member and the toner at the time of transfer. That is, by making the electrophotographic photosensitive member high in hardness, it is an idea that the external additive is more firmly fixed to the toner at the time of rubbing as compared with the conventional electrophotographic photosensitive member.

As a result of the investigation, it was found that, by setting the Martens hardness of the electrophotographic photosensitive member to 245 N / mm ² or more, the detachment of the external additive is extremely difficult to occur when the toner and the electrophotographic photosensitive member rub in the transfer step. . As a result, it was confirmed that the external additive was firmly fixed to the toner, and stable developability could be secured for a long period of time, and no image defect such as fogging was caused.

  As described above, it is possible to contain the external additive having the azo group-containing chromium complex at 1.7% by mass or more with respect to the content of the toner particles, and to make the surface of the electrophotographic photosensitive member high in hardness The synergetic effect of the electrophotographic photosensitive member is exhibited. This makes it possible to achieve the effects of the present invention.

The surface layer of the electrophotographic photosensitive member according to the present invention contains a resin, which is a polyester resin having a structure represented by the general formula (I) and the general formula (II), and a general formula (III) It is at least one selected from polycarbonate resins having the structure shown.
(In the general formula (I), X ¹ represents a single bond, an oxygen atom, a divalent alkylidene group or a divalent cycloalkylidene group. R ^{11 to} R ¹⁸ each independently represent a hydrogen atom or an alkyl group .)
(In the general formula (II), X ² represents a divalent group.)
(In the general formula (III), X ³ represents a single bond, an oxygen atom, a divalent alkylidene group or a divalent cycloalkylidene group. R ^{21 to} R ²⁸ each independently represent a hydrogen atom or an alkyl group. .)
The structure represented by the general formula (I) of the polyester resin preferably has a structure represented by the general formula (I-1).
(In the general formula (I-1), R ^{31 to} R ³⁴ each independently represent a hydrogen atom or a methyl group.)
The structure represented by the general formula (III) above of the polycarbonate resin preferably has a structure represented by the general formula (III-1).
(In the general formula (III-1), R ^{41 to} R ⁴⁴ each independently represent a hydrogen atom or a methyl group.)

  These bisphenol structures are preferable because they can increase the Martens hardness because the benzene ring has a rigid structure.

Further, the structure represented by the general formula (I-1) in the polyester resin is a structure represented by the formula (I-1-1), the formula (1-1-2) and the formula (I-1-3) It is more preferred to have at least one structure selected.
The structure represented by the general formula (III-1) in the polycarbonate resin is selected from the structures represented by the formulas (III-1-1), (III-1-2) and (III-1-3) More preferably, it has at least one structure.

  In this case, by substituting a biphenylene group used as a bisphenol structure with a methyl group, the polarity of the resin of the surface layer of the photoreceptor is reduced, and the resin polarity of the surface layer of the electrophotographic photoreceptor is reduced. Therefore, while enhancing the Martens hardness, as an auxiliary effect, the interaction with the polar group of the toner is weakened, and the effect of further suppressing the adherence of the toner to the photosensitive member surface layer is easily exhibited.

The polyester resin is further selected from Formula (I-2-1), Formula (I-2-2), Formula (I-2-3), Formula (I-2-4) and Formula (I-2-5). It is more preferable to have at least one structure selected from the structures shown in).
The polycarbonate resin is further selected from Formula (III-2-1), Formula (III-2-2), Formula (III-2-3), Formula (III-2-4) and Formula (III-2-5). It is more preferable to have at least one structure selected from the structures shown in).

  In the polyester resin, the proportion of the structure represented by the general formula (I-1) in the structure represented by the general formula (I) is preferably 20 mol% or more. Moreover, it is preferable that the ratio of the structure shown by General formula (III-1) to the structure shown by General formula (III) in said polycarbonate resin is 20 mol% or more.

  The surface layer more preferably contains silica particles having a volume average particle size of 40 nm or more and 200 nm or less. By containing silica particles, the Martens hardness can be increased, and minute irregularities on the surface can be formed, so that an effect of enabling control of the surface adhesion by the irregular surface can be obtained as an auxiliary effect. Examples of silica particles having a volume average particle size of 40 nm or more and 200 nm or less include synthetic silica. Examples of synthetic silica include dry silica particles and wet silica particles. It is preferable that content of a silica particle is 1 to 10% as mass ratio with respect to resin in the said surface layer.

Examples of the dry silica particles include silica particles by a combustion method obtained by burning a silane compound, and silica particles by a deflagration method obtained by explosively burning metal silicon powder.
As wet silica particles, wet silica particles obtained by neutralization reaction of sodium silicate and mineral acid, colloidal silica particles obtained by making acidic silicic acid alkaline and polymerizing, sol-gel method obtained by hydrolysis of organic silane compounds Silica particles are mentioned.
Among them, silica particles by a combustion method are preferable in terms of electrical characteristics. In the case of using wet silica particles, silica is preferable in which impurities such as alkali are reduced by purification or the like.

  When the volume average particle diameter is 40 nm or more, the dispersion in the polyester resin or the polycarbonate resin is difficult to progress, and the surface has a minute unevenness while increasing the Martens hardness. When the volume average particle diameter is 200 nm or less, the unevenness does not become too large, and the toner of the electrophotographic photosensitive member is less likely to be contaminated due to the slip through.

In the present invention, the method of measuring the volume average particle size of the silica particles is as follows.
The silica particles are separated from the layer, 100 primary particles of the silica particles are observed at 100,000 times by SEM (scanning microscope), and the longest diameter and the shortest diameter of each primary particle are measured. Measure the equivalent sphere diameter. The 50% diameter (D50v) in the cumulative frequency of the obtained sphere equivalent diameter is determined, and this is taken as the volume average particle diameter of the silica particles.
With respect to the particle size distribution of silica particles, the volume distribution cumulative value of a half diameter or less of the volume average particle diameter is 10 volume% or less, and the volume distribution cumulative value of a double diameter or more of the volume average particle diameter is 10 volume% or less The particle size distribution of

In the structure represented by the general formula (II), it is more rigid that the polyester resin contains the structures represented by the formulas (II-1) to (II-3), and the surface has a high Martens hardness. It is easy to form a layer and is preferable. Among them, it is more preferable to have a structure represented by Formula (II-1).

[Electrophotographic photosensitive member]
The electrophotographic photosensitive member according to the present invention has a surface layer. Furthermore, it has a support and a photosensitive layer. The photosensitive layer of the electrophotographic photosensitive member is mainly classified into (1) laminated type photosensitive layer and (2) single layer type photosensitive layer. (1) The laminate type photosensitive layer has a charge generation layer containing a charge generation substance and a charge transport layer containing a charge transport substance. (2) The single-layer type photosensitive layer has a photosensitive layer containing both the charge generating substance and the charge transporting substance. In the present invention, when the protective layer is not provided, (1) in the case of the laminated type photosensitive layer, the charge transport layer containing the charge transport substance is the surface layer, and (2) in the case of the single layer type photosensitive layer The photosensitive layer containing the transport substance is the surface layer.

As a method of producing an electrophotographic photosensitive member, there may be mentioned a method of preparing a coating solution for each layer to be described later, applying the solution in the order of desired layers and drying it. At this time, examples of the coating method of the coating liquid include dip coating, spray coating, ink jet coating, roll coating, die coating, blade coating, curtain coating, wire bar coating, ring coating and the like. Among these, dip coating is preferable from the viewpoint of efficiency and productivity.
Hereinafter, the support and each layer will be described.

<Support>
In the present invention, the electrophotographic photosensitive member has a support. In the present invention, the support is preferably a conductive support having conductivity. Moreover, as a shape of a support body, cylindrical shape, belt shape, a sheet shape, etc. are mentioned. Among them, a cylindrical support is preferable. In addition, the surface of the support may be subjected to electrochemical treatment such as anodization, blast treatment, cutting treatment and the like.
As a material of a support body, metal, resin, glass etc. are preferable.
Examples of the metal include aluminum, iron, nickel, copper, gold, stainless steel and alloys thereof. Among them, an aluminum support using aluminum is preferable.
In addition, the resin or glass may be provided with conductivity by a process such as mixing or coating of a conductive material.

<Conductive layer>
In the present invention, a conductive layer may be provided on the support. By providing the conductive layer, it is possible to conceal scratches and irregularities on the surface of the support and to control the reflection of light on the surface of the support.
The conductive layer preferably contains conductive particles and a resin.

Examples of the material of the conductive particles include metal oxides, metals, carbon black and the like.
Examples of metal oxides include zinc oxide, aluminum oxide, indium oxide, silicon oxide, zirconium oxide, tin oxide, titanium oxide, magnesium oxide, antimony oxide, bismuth oxide and the like. Examples of the metal include aluminum, nickel, iron, nichrome, copper, zinc, silver and the like.
Among these, it is preferable to use a metal oxide as the conductive particles, and in particular, it is more preferable to use titanium oxide, tin oxide, or zinc oxide.
When a metal oxide is used as the conductive particles, the surface of the metal oxide may be treated with a silane coupling agent or the metal oxide may be doped with an element such as phosphorus or aluminum or an oxide thereof.
In addition, the conductive particles may have a laminated structure including core material particles and a coating layer that covers the particles. The core particles include titanium oxide, barium sulfate, zinc oxide and the like. The covering layer may, for example, be a metal oxide such as tin oxide.
When a metal oxide is used as the conductive particles, the volume average particle diameter is preferably 1 nm or more and 500 nm or less, and 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, alkyd resin and the like.
In addition, the conductive layer may further contain a masking agent such as silicone oil, resin particles, titanium oxide and the like.

  The average film thickness of the conductive layer is preferably 1 μm or more and 50 μm or less, and particularly preferably 3 μm or more and 40 μm or less.

  The conductive layer can be formed by preparing a coating solution for a conductive layer containing the above-described respective materials and a solvent, forming the coating film, and drying it. Examples of the solvent used for the coating solution include alcohol solvents, sulfoxide solvents, ketone solvents, ether solvents, ester solvents, aromatic hydrocarbon solvents and the like. As a dispersion method for dispersing conductive particles in the coating liquid for conductive layer, a method using a paint shaker, a sand mill, a ball mill, or a liquid collision type high speed disperser can be mentioned.

<Subbing layer>
In the present invention, an undercoat layer may be provided on the support or the conductive layer. By providing the undercoat layer, the adhesion function between the layers can be enhanced and the charge injection blocking function can be imparted.
The undercoat layer preferably contains a resin. Alternatively, the undercoat layer may be formed as a cured film by polymerizing a composition containing a monomer having a polymerizable functional group.

  As resin, polyester resin, polycarbonate resin, polyvinyl acetal resin, acrylic resin, epoxy resin, melamine resin, polyurethane resin, phenol resin, polyvinyl phenol resin, alkyd resin, polyvinyl alcohol resin, polyethylene oxide resin, polypropylene oxide resin, polyamide resin And polyamide acid resin, polyimide resin, polyamide imide resin, cellulose resin and the like.

  As a polymerizable functional group which a monomer having a polymerizable functional group has, an isocyanate group, a blocked isocyanate group, a methylol group, an alkylated methylol group, an epoxy group, a metal alkoxide group, a hydroxyl group, an amino group, a carboxyl group, a thiol group, A carboxylic anhydride group, a carbon-carbon double bond group, etc. are mentioned.

The undercoat layer may further contain an electron transport material, a metal oxide, a metal, a conductive polymer, and the like for the purpose of enhancing the electrical properties. Among these, electron transport substances and metal oxides are preferably used.
Electron transport materials include quinone compounds, imide compounds, benzimidazole compounds, cyclopentadienylidene compounds, fluorenone compounds, xanthone compounds, benzophenone compounds, cyanovinyl compounds, halogenated aryl compounds, silole compounds, boron compounds and the like. . The undercoat layer may be formed as a cured film by copolymerizing with the above-described monomer having a polymerizable functional group, using an electron transport material having a polymerizable functional group as the electron transporting substance.
Examples of metal oxides include indium tin oxide, tin oxide, indium oxide, titanium oxide, zinc oxide, aluminum oxide, silicon dioxide and the like. Examples of the metal include gold, silver and aluminum.
The undercoat layer may further contain an additive.

  The average film thickness of the undercoat layer is preferably 0.1 μm to 50 μm, more preferably 0.2 μm to 40 μm, and particularly preferably 0.3 μm to 30 μm.

  The undercoat layer can be formed by preparing a coating solution for undercoat layer containing the above-described respective materials and a solvent, forming the coating film, and drying and / or curing. Examples of the solvent used for the coating solution include alcohol solvents, ketone solvents, ether solvents, ester solvents, aromatic hydrocarbon solvents and the like.

<Photosensitive layer>
The photosensitive layer of the electrophotographic photosensitive member is mainly classified into (1) laminated type photosensitive layer and (2) single layer type photosensitive layer. (1) The laminated photosensitive layer has a charge generating layer containing a charge generating substance and a charge transporting layer containing a charge transporting substance. (2) The single-layer type photosensitive layer has a photosensitive layer containing both the charge generating substance and the charge transporting substance.

(1) Stacked Photosensitive Layer The stacked photosensitive layer has a charge generation layer and a charge transport layer.

(1-1) Charge Generating Layer The charge generating layer preferably contains a charge generating substance and a resin.

Examples of the charge generating material include azo pigments, perylene pigments, polycyclic quinone pigments, indigo pigments, and phthalocyanine pigments. Among these, azo pigments and phthalocyanine pigments are preferable. Among the phthalocyanine pigments, oxytitanium phthalocyanine pigments, chlorogallium phthalocyanine pigments and hydroxygallium phthalocyanine pigments are preferable.
The content of the charge generation material in the charge generation layer is preferably 40% by mass to 85% by mass, and more preferably 60% by mass to 80% by mass, with respect to the total mass of the charge generation layer. preferable.

  As resin, polyester resin, polycarbonate resin, polyvinyl acetal resin, polyvinyl butyral resin, acrylic resin, silicone resin, epoxy resin, epoxy resin, melamine resin, polyurethane resin, phenol resin, polyvinyl alcohol resin, cellulose resin, polystyrene resin, polyvinyl acetate resin And polyvinyl chloride resin. Among these, polyvinyl butyral resin is more preferable.

  The charge generation layer may further contain an additive such as an antioxidant and an ultraviolet light absorber. Specifically, hindered phenol compounds, hindered amine compounds, sulfur compounds, phosphorus compounds, benzophenone compounds and the like can be mentioned.

  The average film thickness of the charge generation layer is preferably 0.1 μm or more and 1 μm or less, and more preferably 0.15 μm or more and 0.4 μm or less.

  The charge generation layer can be formed by preparing a coating solution for charge generation layer containing the above-mentioned respective materials and a solvent, forming this coating film, and drying it. Examples of the solvent used for the coating solution include alcohol solvents, sulfoxide solvents, ketone solvents, ether solvents, ester solvents, aromatic hydrocarbon solvents and the like.

(1-2) Charge Transport Layer The charge transport layer contains a charge transport substance and a resin.

Examples of the charge transport material include polycyclic aromatic compounds, heterocyclic compounds, hydrazone compounds, styryl compounds, enamine compounds, benzidine compounds, triarylamine compounds, and resins having a group derived from these materials. Be Among these, triarylamine compounds and benzidine compounds are preferable. Among these, triarylamine compounds or benzidine compounds are preferable from the viewpoint of potential stability during repeated use. Also, the charge transport material may contain a plurality of types together. Hereinafter, specific examples of the charge transport material are shown.

  The content of the charge transport material in the charge transport layer is preferably 20% by mass to 60% by mass, and more preferably 30% by mass to 50% by mass, with respect to the total mass of the charge transport layer. preferable.

  When the charge transport layer is a surface layer, the resin includes the polyester resin or polycarbonate resin described above. When the protective layer is provided on the photosensitive layer, examples of the resin included in the charge transport layer include polyester resin, polycarbonate resin, acrylic resin, and polystyrene resin. Among these, polycarbonate resin and polyester resin are preferable. As the polyester resin, a polyarylate resin is particularly preferable.

  The content ratio (mass ratio) of the charge transport substance to the resin is preferably 4:10 to 20:10, and more preferably 5:10 to 10:10. The charge transport layer can be formed by forming a coating of a charge transport layer coating solution prepared by dissolving a charge transport substance and a binder resin in a solvent, and drying the coating.

  The charge transport layer may also contain additives such as an antioxidant, an ultraviolet light absorber, a plasticizer, a leveling agent, a slipperiness imparting agent, and an abrasion resistance improver. Specifically, hindered phenol compounds, hindered amine compounds, sulfur compounds, phosphorus compounds, benzophenone compounds, siloxane modified resins, silicone oils, fluorine resin particles, polystyrene resin particles, polyethylene resin particles, silica particles, alumina particles, boron nitride particles Etc.

  The average film thickness of the charge transport layer is preferably 5 μm or more and 50 μm or less, more preferably 8 μm or more and 40 μm or less, and particularly preferably 10 μm or more and 30 μm or less.

  The charge transport layer can be formed by preparing a coating solution for charge transport layer containing the above-described respective materials and a solvent, forming this coating film, and drying it. Examples of the solvent used for the coating solution include alcohol solvents, ketone solvents, ether solvents, ester solvents, and aromatic hydrocarbon solvents. Among these solvents, ether solvents or aromatic hydrocarbon solvents are preferable.

(2) Single-Layer Type Photosensitive Layer A single-layer type photosensitive layer is formed by preparing a coating solution for a photosensitive layer containing a charge generating substance, charge transporting substance, resin and solvent, forming this coating film, and drying it. can do. The charge generating substance, the charge transporting substance, and the resin are the same as the examples of the material in the above-mentioned “(1) laminated type photosensitive layer”. The average film thickness of the single-layer type photosensitive layer is preferably 10 μm or more and 45 μm or less.

<Protective layer>
In the present invention, a protective layer may be provided on the photosensitive layer as long as the effects of the present invention are not impaired. By providing the protective layer, the durability can be improved. When providing a protective layer, a protective layer becomes a surface layer.

It is preferable that the protective layer as the surface layer has the polyester resin or polycarbonate resin described above, and further contains conductive particles and / or a charge transport material.
The conductive particles include particles of metal oxides such as titanium oxide, zinc oxide, tin oxide and indium oxide.
Examples of the charge transport material include polycyclic aromatic compounds, heterocyclic compounds, hydrazone compounds, styryl compounds, enamine compounds, benzidine compounds, triarylamine compounds, and resins having a group derived from these materials. Among these, triarylamine compounds and benzidine compounds are preferable.

  Examples of the above-described polyester resin or resins which may be contained other than polycarbonate resin include other polycarbonate resins, other polyester resins, acrylic resins, phenoxy resins, polystyrene resins, phenol resins, melamine resins, epoxy resins, etc. . Among them, other polycarbonate resins, other polyester resins and acrylic resins are preferable.

  In addition, the protective layer may be formed as a cured film by polymerizing a composition containing a monomer having a polymerizable functional group. The reaction at that time may, for example, be a thermal polymerization reaction, a photopolymerization reaction or a radiation polymerization reaction. As a polymerizable functional group which the monomer which has a polymerizable functional group has, an acryl group, methacryl group, etc. are mentioned. As a monomer having a polymerizable functional group, a material having a charge transporting ability may be used.

  The protective layer may contain additives such as an antioxidant, an ultraviolet light absorber, a plasticizer, a leveling agent, a slipperiness imparting agent, and an abrasion resistance improver. Specifically, hindered phenol compounds, hindered amine compounds, sulfur compounds, phosphorus compounds, benzophenone compounds, siloxane modified resins, silicone oils, fluorine resin particles, polystyrene resin particles, polyethylene resin particles, silica particles, alumina particles, boron nitride particles Etc.

  The average film thickness of the protective layer is preferably 0.5 μm to 10 μm, and more preferably 1 μm to 7 μm.

  The protective layer can be formed by preparing a coating solution for a protective layer containing the above-described respective materials and a solvent, forming this coating, and drying and / or curing. Examples of the solvent used for the coating solution include alcohol solvents, ketone solvents, ether solvents, sulfoxide solvents, ester solvents, and aromatic hydrocarbon solvents.

[toner]
The toner according to the present invention comprises toner particles having a binder resin and a charge control agent, and an external additive, the charge control agent having an azo group-containing chromium complex, and the addition amount of the external additive is The content is 1.7% by mass or more based on the content of the toner particles.

  The binder resin may, for example, be a thermoplastic binder resin, and specifically, a homopolymer or copolymer (styrene-based resin) of styrenes such as styrene, parachlorostyrene, α-methylstyrene and the like. Methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, lauryl methacrylate, methacryl Homopolymers or copolymers (vinyl-based resins) of esters having a vinyl group such as 2-ethylhexyl acid; homopolymers or copolymers (vinyl-based resins) of vinyl nitriles such as acrylonitrile or methacrylonitrile; Vinyl ethers such as vinyl methyl ether and vinyl isobutyl ether Polymer or copolymer (vinyl resin); homopolymer or copolymer (vinyl resin) of vinyl ketones such as vinyl methyl ketone, vinyl ethyl ketone, vinyl isopropenyl ketone, etc .; ethylene, propylene, butadiene, isoprene, etc. Homopolymers or copolymers (olefin resins) of the olefins of the above; epoxy resins, polyester resins, polyurethane resins, polyamide resins, cellulose resins, non-vinyl condensation resins such as polyether resins, and non-vinyl condensation systems thereof The graft polymer of resin and a vinyl-type monomer, etc. are mentioned. These resins may be used alone or in combination of two or more. Among these, it is preferable to use a styrene-acrylic copolymer as a binder resin because durability and storage stability are improved.

  As a charge control agent, although it has an azo group-containing chromium complex, other charge control agents may be used in combination as long as the effects of the present invention are not inhibited. The charge control agent used in combination may be a known one without particular limitation, but a resin (charge control resin) having a charge control substance can be used. The charge control resin is, for example, a sulfur-containing polymer. As a monomer having a sulfur element for producing a sulfur-containing polymer, styrenesulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid, 2-methacrylamido-2-methylpropanesulfonic acid, vinylsulfonic acid, Methacrylic sulfonic acid etc. are mentioned.

  The addition amount of the charge control agent is determined according to the type of binder resin, the presence or absence of other additives, and the toner production method including the dispersion method, and is not uniquely limited. However, when internally added, it is preferably in the range of 0.1 to 10.0 parts by mass, more preferably 0.1 to 5.0 parts by mass with respect to 100 parts by mass of the binder resin. Used. In the case of external addition, the amount is preferably 0.005 parts by mass or more and 1.000 parts by mass or less, and more preferably 0.010 parts by mass or more and 0.300 parts by mass or less with respect to 100 parts by mass of the toner.

  The toner of the present invention may contain a colorant. As a coloring agent, for example, carbon black, chrome yellow, Hansa yellow, benzidine yellow, Sureren yellow, quinoline yellow, permanent orange GTR, pyrazolone orange, Vulcan orange, watch young red, permanent red, permanent carmine 3B, brilliant carmine 6B, Various pigments such as Dupont oil red, pyrazolone red, lysole red, rhodamine B lake, lake red C, rose bengal, aniline blue, ultramarine blue, chalco oil blue, methylene blue chloride, phthalocyanine blue, phthalocyanine green, phthalocyanine green, malachite green oxalate Acridine type, xanthene type, azo type, benzoquinone type, azine type, anthraquinone type, dioxazine , Thiazine, azomethine, indigo, thioindigo, phthalocyanine, aniline black, polymethine, triphenylmethane dyes, diphenylmethane dyes, thiazine, thiazole type, various dyes such as xanthene; and the like. These colorants may be used alone or in combination of two or more.

Also, conventionally known magnetic materials may be used. Examples of magnetic materials contained in the toner include iron oxides such as magnetite, maghemite and ferrite, and other metal oxides such as iron oxides, metals such as Fe, Co and Ni, or these metals and Al, Co, Cu, Examples thereof include alloys with metals such as Pb, Mg, Ni, Sn, Zn, Sb, Be, Bi, Cd, Ca, Mn, Se, Ti, W, and V, and mixtures thereof. Specifically, iron trioxide (Fe ₃ O ₄ ), iron trioxide (γ-Fe ₂ O ₃ ), iron zinc oxide (ZnFe ₂ O ₄ ), iron yttrium oxide (Y ₃ Fe ₅ O ₁₂ ), iron oxide cadmium (CdFe ₂ O _4), iron oxide gadolinium _{(Gd 3 Fe 5 O 12)} , oxidized iron-copper (CuFe ₂ O _4), oxidation Tetsunamari _(PbFe 12 _{O 19),} iron oxide nickel (NiFe ₂ O ₄ ), Iron oxide neodymium oxide (NdFe ₂ O ₃ ), barium iron oxide (BaFe ₁₂ O ₁₉ ), iron magnesium oxide (MgFe ₂ O ₄ ), iron manganese oxide (MnFe ₂ O ₄ ), lanthanum iron oxide (LaFeO ₃ ), Iron powder (Fe), cobalt powder (Co), nickel powder (Ni) and the like can be mentioned.

  In the present invention, a mold release agent can also be contained as needed. The releasing agent usable in the toner according to the present invention is, for example, aliphatic hydrocarbon waxes such as low molecular weight polyethylene, low molecular weight polypropylene, microcrystalline wax, paraffin wax; aliphatic hydrocarbon waxes such as oxidized polyethylene wax Oxides or block copolymers thereof; waxes having a fatty acid ester as a main component, such as carnauba wax, sazole wax, montanic acid ester wax; some or all of fatty acid esters such as deacidified carnauba wax Deoxidized; saturated straight-chain fatty acids such as palmitic acid, stearic acid, montanic acid; unsaturated fatty acids such as brushic acid, eleostearic acid, valinaric acid; stearyl alcohol, aralkyl alcohol, behenyl alcohol, carnauvir Alcohol, Seri Alcohols, saturated alcohols such as melysyl alcohol; polyhydric alcohols such as sorbitol; fatty acid amides such as linoleic acid amide, oleic acid amide, lauric acid amide; methylenebisstearic acid amide, ethylene biscapric acid amide, ethylene bis Saturated fatty acid bisamides such as lauric acid amide, hexamethylene bis-stearic acid amide; ethylene bis oleic acid amide, hexamethylene bis oleic acid amide, N, N'-dioleyl adipic acid amide, N, N'-dioleyl sebacic acid Unsaturated fatty acid amides such as amide; aromatic bisamides such as m-xylene bis-stearic acid amide, N, N'-distearyl isophthalic acid amide; calcium stearate, calcium furinate, zinc stearate, magnesium stearate Aliphatic metal salts such as aluminum (generally referred to as metal soaps); waxes grafted with aliphatic hydrocarbon waxes using vinyl monomers such as styrene and acrylic acid; and behenic acid monoglycerides, etc. Partially esterified fatty acid and polyhydric alcohol; methyl ester compound having a hydroxyl group obtained by hydrogenation of vegetable oil and the like; long-chain alkyl alcohol having 12 or more carbon atoms or long-chain alkyl carboxylic acid; These release agents may be used alone or in combination of two or more.

  As the external additive, inorganic fine powders such as silica, titanium oxide and alumina can be used. As the silica, for example, both a so-called dry method or dry silica called fumed silica produced by vapor phase oxidation of silicon halide, and so-called wet silica produced from water glass or the like can be used. As the number average primary particle diameter of the external additive, it is preferable to add an inorganic fine powder of 4 nm or more and 60 nm or less, more preferably 6 nm or more and 40 nm or less. The inorganic fine powder is added to improve the fluidity of the toner and to uniformly charge the toner particles, but the inorganic fine powder is subjected to a treatment such as hydrophobization to adjust the charge amount of the toner, to improve the environmental stability, etc. It is also a preferable form to impart the function of

  As described above, the additive amount of the external additive is essentially 1.7% by mass with respect to the content of toner particles. However, since the addition of less than 5.0 parts by mass does not inhibit the fixability, it is preferably less than 5.0 parts by mass.

  In addition, other additives such as polytetrafluoroethylene powder, zinc stearate powder, lubricant powder such as polyvinylidene fluoride powder, or cerium oxide powder, carbonized within a range that does not substantially adversely affect the toner of the present invention Polishing agents such as boron powder, strontium titanate powder, or flowability-imparting agents such as titanium oxide powder, aluminum oxide powder, etc., anti-caking agent, organic fine particles of reverse polarity, and inorganic fine particles as a developability improver It can also be used. These additives can also be used after the surface is hydrophobized.

  The toner of the present invention can be produced by any known method, but from the viewpoint of maintaining the cleaning property, a pulverizing method capable of controlling the surface shape, and an emulsion polymerization method are preferable.

  In the case of manufacturing by a pulverizing method, for example, a binder resin, a colorant, an ester compound, a low melting point substance, components necessary as a toner such as a charge control agent, and other additives etc. Mix well. Thereafter, the toner material is dispersed or dissolved by melt-kneading using a heat kneader such as a heating roll, a kneader or an extruder, cooled and solidified, crushed, classified, and optionally subjected to surface treatment to obtain toner particles. be able to. The order of classification and surface treatment may be first. In the classification step, it is preferable to use a multi-division classifier in view of production efficiency.

  The pulverizing step can be carried out by a method using a known pulverizing apparatus such as a mechanical impact type or jet type. Further, in order to obtain the toner having the preferable degree of circularity of the present invention, it is preferable to apply heat to further pulverize, or to perform processing for applying a mechanical impact as a support. In addition, a hot water bath method in which finely pulverized (sorted if necessary) toner particles are dispersed in hot water, a method of passing in a hot air stream, or the like may be used. Examples of means for applying mechanical impact force include a method using a mechanical impact crusher such as Kryptron system manufactured by Kawasaki Heavy Industries, Ltd. or a turbo mill manufactured by Turbo Kogyo Co., Ltd. Also, there is a method of pressing the toner on the inside of the casing by centrifugal force by blades rotating at high speed, and applying mechanical impact force to the toner by force such as compression force and frictional force. As an apparatus using this method, an apparatus such as a mechanofusion system manufactured by Hosokawa Micron Corporation or a hybridization system manufactured by Nara Machinery Co., Ltd. may be mentioned.

  In the case of production by emulsion polymerization, the following two steps are included. First, a resin particle dispersion liquid in which resin particles are dispersed, a colorant dispersion liquid in which a colorant is dispersed, and a release agent dispersion liquid in which a release agent is dispersed are mixed. Thereby, the step of aggregating the resin particles, the coloring agent, and the releasing agent to form aggregated particles to prepare an aggregated particle dispersion (hereinafter, also referred to as "aggregation step"). In the second step, the aggregated particles are heated and fused to form toner particles (hereinafter, may be referred to as "fusion step").

  In the aggregation step, the resin particle dispersion liquid, the colorant dispersion liquid, and the resin particles dispersed in the release agent dispersion liquid, the colorant and the release agent are aggregated to form aggregated particles. Ru. The aggregated particles are formed by hetero aggregation or the like. For example, the balance of the polarity and amount of the ionic surfactant contained in the dispersion to be added and the dispersion to be added is shifted in advance, and an ionic interface of such polarity and amount as to compensate for the deviation of the balance. It is formed by adding an activator.

  In the aggregation step, an ionic surfactant having a polarity different from that of the aggregated particles, and a compound having a charge of a monovalent or more monovalent metal or the like are added for the purpose of stabilization of the aggregated particles and control of particle size / size distribution. Cohesive particles are formed thereby. Further, by changing the pH, aggregation can be controlled and the particle size of the particles can be adjusted. Further, as a method of obtaining agglomerated particles having a narrower particle size distribution, an aggregating agent may be added.

  As the aggregating agent, a compound having a charge of one or more valences is preferable. Specifically, in addition to water-soluble surfactants such as ionic surfactants and nonionic surfactants, acids such as hydrochloric acid, sulfuric acid, nitric acid, acetic acid, oxalic acid, magnesium chloride, sodium chloride, aluminum sulfate Metal salts of inorganic acids such as calcium sulfate, ammonium sulfate, aluminum nitrate, silver nitrate, copper sulfate, sodium carbonate, etc., aliphatic acids such as sodium nitrate, potassium formate, sodium oxalate, sodium phthalate, potassium salicylate, aromatic acids Examples thereof include metal salts, metal salts of phenols such as sodium phenolate, metal salts of amino acids, aliphatic amines such as triethanolamine hydrochloride and aniline hydrochloride, and inorganic acid salts of aromatic amines.

  The addition amount of these aggregating agents varies depending on the valence of the charge, but each of them is a small amount, and in the case of about 3 parts by mass or less, in the case of one per 100 parts by mass of binder resin fine particles. Is about 1 part by mass or less, and in the case of trivalent, it is about 0.5 parts by mass or less. Since the amount of the aggregating agent is preferably small, a compound having a high valence is preferable.

  In the present invention, between the aggregation step and the fusion step, a fine particle dispersion liquid in which fine particles are dispersed is added to and mixed with the agglomerated particle dispersion liquid, and the fine particles are attached to the agglomerated particles to form adhered particles. A process (adhesion process) can also be provided. By providing the adhesion step, a pseudo shell structure can be formed, exposure of the toner surface of internal additives such as a coloring agent and a release agent can be reduced, and the life of the toner can be improved. In addition, at the time of fusion in the fusion step, the particle size distribution can be maintained and the fluctuation thereof can be suppressed. Furthermore, in some cases it may be unnecessary to add a surfactant or a stabilizer such as a base or an acid to increase the stability at the time of fusion, and the amount of addition can be suppressed even when it is not necessary to reduce cost. This is advantageous in that the quality can be improved. By using this method, it is possible to easily control the toner shape by adjusting the temperature, the number of agitation, the pH and the like in the fusion step.

  Further, it is preferable to use, as a dispersant, surfactants such as anionic surfactants, cationic surfactants, nonionic surfactants and the like in the above-mentioned respective dispersions. Among these, it is more preferable to use an anionic surfactant which has a strong dispersing power and is excellent in dispersing the binder resin fine particles, the colorant and the like.

  The content of the surfactant in each dispersion is generally small. Specifically, it is preferably in the range of 0.01% by mass or more and 10.0% by mass or less, and more preferably 0.05% by mass or more and 5.0% by mass or less with respect to 100% by mass of the dispersion medium. preferable. When the content is 0.01% by mass or more, the dispersion of the respective dispersions such as the binder resin fine particle dispersion, the colorant dispersion, the release agent dispersion and the like is stabilized and aggregation does not occur. Therefore, problems such as the release of specific particles due to the difference in stability between the particles at the time of aggregation do not occur. If it is 10.0 mass% or less, the particle size distribution of particles does not become too wide, and control of particle diameter is easy.

  The aggregated particles thus formed are heat-treated to a temperature above the glass transition temperature of the resin to fuse the aggregated particles, obtain a toner particle-containing liquid (toner particle dispersion), and cool it. Next, the obtained toner particle-containing liquid is treated by centrifugation or suction filtration to separate toner particles and washed with ion-exchanged water 1 to 3 times. At that time, the washing effect can be further enhanced by adjusting the pH. Thereafter, the toner particles are separated by filtration, washed with ion-exchanged water 1 to 3 times, and dried to obtain a toner.

[Process cartridge, electrophotographic apparatus]
The process cartridge according to the present invention is characterized by integrally supporting the electrophotographic photosensitive member described above, a charging member, a developing member, and a transfer member, and being detachable from the electrophotographic apparatus main body.

  An electrophotographic apparatus according to the present invention is characterized by including the electrophotographic photosensitive member, the charging unit, the exposure unit, the developing unit, and the transfer unit described above.

FIG. 1 shows an example of a schematic configuration of an electrophotographic apparatus having a process cartridge provided with an electrophotographic photosensitive member.
A cylindrical electrophotographic photosensitive member 1 is rotationally driven around an axis 2 in the direction of the arrow at a predetermined peripheral speed. The surface of the electrophotographic photosensitive member 1 is charged by the charging unit 3 to a predetermined positive or negative potential. Although the roller charging system using a roller type charging member is shown in the drawing, a charging system such as a corona charging system, a proximity charging system, or an injection charging system may be employed. Exposure light 4 is irradiated from the exposure means (not shown) on the charged surface of the electrophotographic photosensitive member 1 to form an electrostatic latent image corresponding to the target image information. The electrostatic latent image formed on the surface of the electrophotographic photosensitive member 1 is developed by the toner contained in the developing means 5, and a toner image is formed on the surface of the electrophotographic photosensitive member 1. The toner image formed on the surface of the electrophotographic photosensitive member 1 is transferred to the transfer material 7 by the transfer means 6. The transfer material 7 to which the toner image has been transferred is conveyed to the fixing means 8, subjected to the fixing process of the toner image, and printed out of the electrophotographic apparatus. The electrophotographic apparatus may have a cleaning means 9 for removing deposits such as toner remaining on the surface of the electrophotographic photosensitive member 1 after transfer. In addition, a so-called cleaner-less system may be used in which the attached matter is removed by a developing means or the like without separately providing a cleaning means. The electrophotographic apparatus may have a diselectrification mechanism for diselectrifying the surface of the electrophotographic photosensitive member 1 with pre-exposure light 10 from a pre-exposure means (not shown). Further, in order to attach and detach the process cartridge 11 according to the present invention to the electrophotographic apparatus main body, a guide means 12 such as a rail may be provided.

  The electrophotographic photosensitive member according to the present invention can be used for a laser beam printer, an LED printer, a copying machine, a facsimile, a composite machine of these, and the like.

  Hereinafter, the present invention will be described in more detail using examples and comparative examples. The present invention is not limited at all by the following examples unless the gist is exceeded. In the following description of the examples, "part" is on a mass basis unless otherwise noted.

[Production example of polyester resin]
<Polyester resin (1)>
41.3 g of a dicarboxylic acid halide represented by the following formula:
12.2 g of dicarboxylic acid halide represented by the following formula
Was dissolved in dichloromethane to prepare an acid halide solution. Also, separately, 24.2 g of diol represented by the following formula,
27 g of diol represented by the following formula
Was dissolved in a 10% aqueous solution of sodium hydroxide, tributylbenzylammonium chloride was added as a polymerization catalyst, and the mixture was stirred to prepare a diol compound solution.
Next, the acid halide solution was added to the diol compound solution while stirring to initiate polymerization. The polymerization was carried out for 3 hours with stirring while maintaining the reaction temperature at 25 ° C. or less.
During the polymerization reaction, p-tert-butylphenol was added as a polymerization modifier. Thereafter, the polymerization reaction was terminated by the addition of acetic acid, and washing with water was repeated until the aqueous phase became neutral.
After washing, the dichloromethane solution was dropped into methanol under stirring to precipitate a polymer, and the polymer was dried under vacuum to obtain a polyester resin (1).

  The obtained polyester resin (1) has 50 mol% of the structure represented by the formula (I-1-1) and the structure represented by the formula (I-2-1) as a structure represented by the general formula (I) It had 50 mol%. Moreover, it was a polyester resin which has 70 mol% of structures shown by Formula (II-1), and 30 mol% of structures shown by Formula (II-2) as a structure shown by General formula (II).

<Polyester resin (2) to (15)>
The polyester resin (1) was produced in the same manner as the polyester resin (1) except that the types and amounts of the dicarboxylic acid halide and the diol used were changed in the production example of the polyester resin (1). Table 1 shows the structure and ratio of the produced polyester resin.

[Production Example of Polycarbonate Resin]
<Polycarbonate resin (1)>
24.2 g of a diol represented by the following formula in 1100 ml of a 5% by mass aqueous solution of sodium hydroxide,
27.0 g of diol represented by the following formula
And 0.1 g of hydrosulfite were dissolved. To this was added 500 ml of methylene chloride, and while stirring and maintaining at 15 ° C., 60 g of phosgene was then blown in over 60 minutes.
After completion of the phosgene bubbling, 1 g of p-tertiary butyl phenol was added as a molecular weight modifier and the mixture was stirred to emulsify the reaction liquid. After emulsification, 0.3 ml of triethylamine was added, and the mixture was stirred at 23 ° C. for 1 hour for polymerization.
After completion of the polymerization, the reaction solution was separated into an aqueous phase and an organic phase, the organic phase was neutralized with phosphoric acid, and water washing was repeated until the conductivity of the washing solution (water phase) became 10 μS / cm or less. The obtained polymer solution was added dropwise to warm water maintained at 45 ° C., and the solvent was removed by evaporation to obtain a white powdery precipitate. The resulting precipitate was filtered and dried at 110 ° C. for 24 hours to obtain polycarbonate resin (1). The obtained polycarbonate resin (1) has 50 mol% of the structure represented by the formula (III-1-1) and the structure represented by the formula (III-2-1) as a structure represented by the general formula (III) It was a polycarbonate resin having 50 mol%.

<Polycarbonate resin (2) to (10)>
It manufactured similarly to polycarbonate resin (1) except having changed the kind and quantity of diol to be used in the manufacture example of polycarbonate resin (1). Table 2 shows the structure and ratio of the produced polycarbonate resin.

[Production example of electrophotographic photosensitive member]
<Electrophotographic photosensitive member (1)>
An aluminum cylinder having a diameter of 24 mm and a length of 257 mm was used as a support (conductive support).

(Conductive layer)
Next, 100 parts of zinc oxide particles (specific surface area: 15 m 2 / g, average particle size: 70 nm, powder resistance: 3.7 × 10 5 Ω · cm) were stirred and mixed with 500 parts of toluene.
To this, 1.5 parts of N- (2-aminoethyl) -3-aminopropyltrimethoxysilane as a silane coupling agent was added and stirred for 6 hours.
Then, toluene was distilled off under reduced pressure and the residue was heated at 140 ° C. for 6 hours for drying to obtain zinc oxide particles surface-treated with a silane coupling agent.

Next, 15 parts of butyral resin (trade name: BM-1, manufactured by Sekisui Chemical Co., Ltd.) as a polyol resin and blocked isocyanate (trade name: Desmodur BL 3175/1, manufactured by Sumika Bayer Urethane Co., Ltd.) We prepared 15 copies. These were dissolved in a mixed solvent of 73.5 parts of methyl ethyl ketone / 73.5 parts of 1-butanol.
To this solution were added 81 parts of zinc oxide particles surface-treated with the above-mentioned silane coupling agent, 0.8 parts of 2,3,4-trihydroxybenzophenone, and 0.81 parts of zinc octylate. This was placed in a sand mill using glass beads with a diameter of 0.8 mm, and dispersed for 3 hours under an atmosphere of 23 ± 3 ° C.
After the dispersion treatment, 5 parts of silicone oil (trade name: SH28PA, manufactured by Toray Dow Corning Silicone Co., Ltd.) 0.01 part and silicone resin particles (trade name: Tospearl 145, manufactured by GE Toshiba Silicone Co., Ltd.) .6 copies were added. Then, the coating liquid for electrically conductive layers was prepared by stirring.
The coating solution for a conductive layer was dip-coated on the support, and the obtained coating film was dried at 150 ° C. for 30 minutes and thermally cured to form a conductive layer having a thickness of 30 μm.

(Undercoat layer)
Next, 8.5 parts of a compound represented by the following formula as a charge transporting substance,
15 parts of blocked isocyanate compounds (trade name: SBN-70D, manufactured by Asahi Kasei Chemicals Corporation) were prepared. In addition, as the resin, 0.97 parts of polyvinyl alcohol resin (trade name: KS-5Z, manufactured by Sekisui Chemical Co., Ltd.) and 0.15 parts of zinc hexanoate (II) as a catalyst were prepared. These were dissolved in a mixed solvent of 88 parts of 1-methoxy-2-propanol and 88 parts of tetrahydrofuran.
Silica slurry having an average primary particle diameter of 9-15 nm dispersed in isopropyl alcohol in this solution (Product name: IPA-ST-UP, manufactured by Nissan Chemical Industries, Ltd., solid content concentration: 15% by mass, viscosity: 9 mPa · 1.8 parts of s) was added through a nylon screen mesh sheet and stirred for 1 hour. Then, it pressure-filtered using the filter and prepared the coating liquid for undercoat.
The undercoat layer coating solution is dip-coated on the conductive layer, and the obtained coating film is heated at 170 ° C. for 20 minutes to cure (polymerize), whereby the film thickness is 0.7 μm or less on the conductive layer. A pull layer was formed.

(Charge generation layer)
Next, 2 parts of polyvinyl butyral (trade name: SLEC BX-1, manufactured by Sekisui Chemical Co., Ltd.) was dissolved in 100 parts of cyclohexanone.
To this solution was added 4 parts of hydroxygallium phthalocyanine crystal (charge generating substance) having a strong peak at 7.4 ° and 28.1 ° of Bragg angle 2θ ± 0.2 ° in CuKα characteristic X-ray diffraction. .
This was placed in a sand mill using glass beads with a diameter of 1 mm, and dispersed for 1 hour in an atmosphere of 23 ± 3 ° C. After the dispersion treatment, 100 parts of ethyl acetate was added thereto to prepare a coating solution for charge generation layer.
The coating solution for charge generation layer was dip-coated on the undercoat layer, and the obtained coating film was dried at 90 ° C. for 10 minutes to form a charge generation layer having a thickness of 0.20 μm.

(Charge transport layer)
Next, 7.2 parts of a compound represented by the formula (CTM-1), 0.8 parts of a compound represented by the formula (CTM-2), and 10 parts of a polyester resin (1) synthesized in the polyester resin production example are prepared. did. These were dissolved in a mixed solution of 33 parts of dimethoxymethane, 15 parts of ortho-xylene and 25 parts of methyl benzoate to prepare a charge transport layer coating solution.
The charge transport layer coating solution is dip-coated on the charge generation layer to form a coating film, and the obtained coating film is dried at 130 ° C. for 30 minutes to form a charge transport layer having a thickness of 22 μm (surface Layer).
Thus, an electrophotographic photosensitive member (1) having a support, a conductive layer, an undercoat layer, a charge generation layer and a charge transport layer in this order was produced.

(Martens hardness of surface layer of electrophotographic photosensitive member)
The Martens hardness of the surface layer of the electrophotographic photosensitive member can be measured by using a microhardness measurement apparatus (trade name: Picodenter HM500, manufactured by Fisher Instruments Inc.). Under an environment of a temperature of 25 ° C. and a relative humidity of 50%, an indenter of square pyramidal diamond can be applied to the measurement site, and measurement can be performed under the condition of indentation speed of the following formula (1).
dF / dt = 0.1 mN / 10 s (1)
Here, F represents force and t represents time. In the evaluation of the surface layer of the electrophotographic photosensitive member, the hardness when the indenter is pressed in with a force of 7 mN is extracted from the measurement result to obtain the Martens hardness.
The measurement result of the above-mentioned Martens hardness is displayed as "evaluation 1" in an example.
The Martens hardness of the surface layer of the electrophotographic photosensitive member was measured by the method described above. The Martens hardness of the surface layer of the electrophotographic photosensitive member (1) was 275 N / mm ² .

<Electrophotographic photosensitive members (2) to (14), (20) to (29), (34)>
The electrophotographic photosensitive member (1) was manufactured in the same manner as the electrophotographic photosensitive member (1) except that the type of polyester resin or polycarbonate resin was changed as shown in Table 3. Table 3 shows the details of the produced electrophotographic photosensitive member and the evaluation results.

<Electrophotographic photosensitive member (15)>
A support, a conductive layer, an undercoat layer, a charge generation layer and a charge transport layer are provided in this order by the same procedure as the electrophotographic photosensitive member (1) except that the method of producing the charge transport layer is changed as follows. An electrophotographic photosensitive member (15) was produced. Table 3 shows the details of the produced electrophotographic photosensitive member and the evaluation results.

(Charge transport layer of electrophotographic photoreceptor (15))
Add 0.1 parts of silica particles (trade name: OX50, manufactured by Nippon Aerosil Co., Ltd.) to a solution of 9.9 parts of cyclopentanone, disperse it using an ultrasonic disperser for 2 hours, and disperse silica dispersion 10 I got a department.
7.2 parts of a compound represented by the formula (CTM-1), 0.8 parts of a compound represented by the formula (CTM-3), and 10 parts of the polyester resin (2) synthesized in the production example of polyester resin, dimethoxymethane 40 The mixture was dissolved in a mixed solution of 50 parts of cyclopentanone and 50 parts of cyclopentanone. To this, 10 parts of silica dispersion was added to prepare a charge transport layer coating solution.
The charge transport layer coating solution is dip-coated on the charge generation layer to form a coating film, and the obtained coating film is dried at 130 ° C. for 30 minutes to form a charge transport layer having a thickness of 22 μm (surface Layer).

<Electrophotographic photosensitive members (16) to (19), (30) to (33), (35)>
The electrophotographic photosensitive member (15) was manufactured in the same manner as the electrophotographic photosensitive member (15) except that the type of polyester resin or polycarbonate resin, the type of silica particles, the particle diameter and the number of parts were changed as shown in Table 3. Table 3 shows the details of the produced electrophotographic photosensitive member and the evaluation results.

The silica particles used in Table 3 will be described.
OX50: Fumed silica not treated with surface (trade name: OX50, manufactured by Nippon Aerosil Co., Ltd.)
N2N: Wet-treated silica not surface-treated (trade name: N2N, manufactured by Ube Eximo Co., Ltd.)

[Production example of toner]
<Production 1 of Charge Control Agent>
By adding 60 ml of water, 17 g of 37% hydrochloric acid and 15 g of 4-chloro-2-aminophenol to a 250 ml three-necked flask at room temperature and stirring over 0.5 hours, 4-chloro is obtained. Dissolve -2-aminophenol in hydrochloric acid and lower the temperature of this aqueous solution to 5 ° C, then add 11 g of 35% strength sodium nitrite solution, so that the temperature of this system does not exceed 5 ° C, The diazo salt solution was obtained as a reaction liquid by making it react for 2 hours, hold | maintaining the temperature of the said system in the range of 0-5 degreeC.

On the other hand, 2-naphthol is sodium hydroxide by charging 50 ml of water, 18 g of 25% strength sodium hydroxide solution and 8 g of 2-naphthol in a 500 ml three-necked flask and stirring for 0.5 hours. A naphthol solution dissolved in an aqueous solution was obtained.
After lowering the temperature of the obtained naphthol solution to 20 ° C., the diazo salt solution was added dropwise while controlling the temperature of the system not to exceed 25 ° C. Thereafter, while controlling the temperature of the system to be in the range of 20 ± 5 ° C., the coupling reaction of the diazo salt derived from 4-chloro-2-aminophenol and 2-naphthol was performed over 5 hours. Thus, a suspension containing an azo compound as a reaction solution (hereinafter, also referred to as “raw material azo compound suspension (1)”) was obtained.

To the obtained raw material azo compound suspension (1), 95.5 g of a 10% aqueous solution of sodium chromium salicylate having a concentration of 10% as a complexing agent was dropped. Next, 1 g of benzyltriethyl ammonium chloride as a specific additive compound and 1 g of sodium carbonate as an inorganic weak alkali compound were added. Thereafter, the temperature of the system is raised to 100 ° C., complex formation reaction is carried out over 10 hours under the condition of 100 ° C. reaction temperature, then the temperature of the system is lowered to 60 ° C., and the obtained reaction solution is filtered. The reaction product was recovered by The reaction product was washed with water to obtain a wet cake, which was dried at a temperature of 80 ° C. As a result, 17.5 g of a charge control agent (hereinafter, referred to as "charge control agent (A)") composed of an azo chromium complex represented by the following chemical formula (A) was obtained.

<Production 2 of charge control agent>
In Production Example 1 of Charge Control Agent, the obtained wet cake was placed in an acidic aqueous solution consisting of 125 g of water and 37% hydrochloric acid, and ion exchange treatment was carried out at a temperature of 55 ° C. for 1 hour. Thereafter, it was filtered, washed with water and dried under conditions of 80 ° C. As a result, a charge control agent (hereinafter referred to as “the charge control agent comprising a mixture of 30% by mass of the azo-based chromium complex represented by the chemical formula (A) and 70% by mass of the azo-based chromium complex represented by the following chemical formula (B) 17.0 g of a charge control agent (B) was obtained.

<Production of charge control agent 3>
At room temperature, 60 ml of water, 17 g of 37% hydrochloric acid, and 11.6 g of 4,6-dinitro-2-aminophenol are charged in a 250 ml three-necked flask and stirred for 0.5 hours, The temperature of this aqueous solution was lowered to 5 ° C. Thereafter, 11 g of sodium nitrite solution having a concentration of 35% is added while cooling so that the temperature of the system is 15 ° C. or less, and the reaction is carried out under the conditions of 10 ° C. for 4 hours to obtain a diazo salt suspension as a reaction liquid. Obtained.

On the other hand, 50 ml of water, 18 g of 25% strength sodium hydroxide solution and 14.5 g of 3-hydroxy-2-naphthanilide were charged in a 500 ml three-necked flask and stirred for 0.5 hours. Thus, a naphthanilide solution in which 3-hydroxy-2-naphthanilide was dissolved in an aqueous sodium hydroxide solution was obtained.
After the temperature of the obtained naphthanilide solution was lowered to 20 ° C., the diazo salt suspension was added dropwise while controlling the temperature of the system not to exceed 30 ° C. Thereafter, while controlling the temperature of the system to be within the range of 25 ± 5 ° C., the diazo salt derived from 4,6-dinitro-2-aminophenol and 3-hydroxy-2-naphthanilide are taken over 5 hours. The coupling reaction was performed. Thus, a suspension containing an azo compound as a reaction solution (hereinafter, also referred to as “raw material azo compound suspension (2)”) was obtained.

To the obtained raw material azo compound suspension (2), 95.5 g of a 10% aqueous solution of sodium chromate having a concentration of 10% as a complexing agent was dropped. Next, 5 ml of N, N-dimethylformiamide (DMF) as a strong polar solvent and 1 g of sodium carbonate as an inorganic weak alkali compound were added. Thereafter, the temperature of the system is raised to 100 ° C., complex formation reaction is performed over 12 hours under the condition of 100 ° C. reaction temperature, then the temperature of the system is lowered to 60 ° C., and the obtained reaction solution is filtered. The reaction product was recovered by The reaction product was washed with water to obtain a wet cake, which was dried at a temperature of 80 ° C. As a result, 26.0 g of a charge control agent (hereinafter, also referred to as "charge control agent (C)") composed of an azo-based chromium complex represented by the following chemical formula (C) was obtained.

<Production of charge control agent 4>
In Example 3, the obtained wet cake was placed in an inorganic ammonium aqueous solution consisting of 125 g of water, 26 g of ethanol and 19.5 g of ammonium chloride, and ion exchange treatment was performed at a temperature of 80 ° C. for 1 hour. Thereafter, a charge control agent comprising an azo-based chromium complex represented by the following chemical formula (D) by filtering, washing with water and drying at conditions of 90 ° C. (hereinafter, “charge control agent (D) "I got it." I got 25.5 g.

<Production of Toner 1>
1 part by mass of charge control agent (A), 100 parts by mass of styrene acrylic resin, 8 parts by mass of carbon black "Mogal L" (manufactured by Cabot), and 6 parts by mass of low molecular weight polypropylene "660P" (manufactured by Sanyo Chemical Industries, Ltd.) The parts were mixed by means of a Henschel mixer. The styrene acrylic resin used is a styrene acrylic resin (styrene: butyl acrylate: methyl methacrylate = 70: 20: 5 (mass ratio)). The resulting mixture is melt-kneaded using a twin-screw extruder, cooled, and then crushed using a jet mill and classified using a cyclone classifier to obtain a median diameter on a volume basis of 7.5 μm. Colored particles were obtained.
Then, 1.7 parts by mass of hydrophobic silica having a number average primary particle diameter of 12 nm and a degree of hydrophobicity of 67 is added to 100 parts by mass of the obtained colored particles and mixed using a Henschel mixer , Toner 1 was obtained.

<Production of Toner 2>
Toner 2 was obtained in the same manner as toner 1 except that the amount of hydrophobic silica added was changed to 2.6 parts by mass.

<Production of Toner 3>
(Preparation of Colorant Dispersion)
50 parts by mass of carbon black (BET 60 m ² / g), 3 parts by mass of an ionic surfactant (Neogen RK, Dai-ichi Kogyo Seiyaku Co., Ltd.), and 400 parts by mass of ion exchange water are mixed to obtain a homogenizer (manufactured by IKA: Ultratarax) ) To obtain a colorant dispersion.

(Preparation of resin fine particle dispersion)
7 parts by mass of a nonionic surfactant (manufactured by Sanyo Chemical Industries, Ltd .: Novonyl) and 10 parts by mass of an anionic surfactant (manufactured by Daiichi Kogyo Seiyaku Co., Ltd .: Neogen RK) are dissolved in 520 parts by mass of ion exchanged water An agent solution was prepared. A solution prepared by previously mixing, dissolving, and adjusting the surfactant solution, 280 parts by mass of styrene, 100 parts by mass of n-butyl acrylate, 7 parts by mass of acrylic acid, and 15 parts by mass of charge control agent (A) is charged into a flask. Emulsified. While slowly mixing for 10 minutes, 70 parts by mass of ion exchanged water in which 3 parts by mass of ammonium persulfate was dissolved was further added. After sufficient nitrogen substitution, while stirring the flask, the contents were heated to 70 ° C. in an oil bath, and the emulsion polymerization was continued for 6 hours.
Thereafter, the reaction solution was cooled to room temperature to obtain a resin fine particle dispersion having a weight average particle diameter (D4) of 150 nm and a glass transition temperature of 57.0 ° C.
A Microtrac particle size distribution measuring device (manufactured by Nikkiso Co., Ltd.) was used to measure the weight average particle diameter. In the measurement by this microtrack particle size distribution measuring device, the measurement was performed under the conditions of measurement range = 0.12 to 704 m, measurement time = 30 seconds, and medium = ion exchange water.

(Preparation of mold release agent dispersion)
As a mold release agent, 200 parts by mass of behenyl behenate, 3 parts by mass of an anionic surfactant (manufactured by Takemoto Yushi Co., Ltd .: Pionin A-45-D), and 700 parts by mass of ion exchange water were mixed. Thereafter, the mixture was dispersed using a homogenizer (manufactured by IKA: Ultra-Turrax), and dispersion treatment was performed using a pressure discharge type homogenizer to obtain a release agent dispersion (1).

(Manufacturing of toner particles)
-300 parts by mass of resin particle dispersion-200 parts by mass of colorant dispersion-100 parts by mass of release agent dispersion-Cationic surfactant (Kao Co., Ltd .: Sanizol B50) 3 parts by mass-Ion exchanged water 500 parts by mass Each component was mixed and dispersed in a round bottom stainless steel flask using a homogenizer (manufactured by IKA, Ultra-Turrax T50). Thereafter, the pH was adjusted, and the mixture was heated to 50 ° C. with a heating oil bath while heating, and held at 50 ° C. for 30 minutes to form aggregated particles. 30 parts of a resin particle dispersion was added to the aggregated particle liquid, and the mixture was further heated and stirred at 50 ° C. for 3 hours.
Then, 6 parts of sodium dodecylbenzene sulfonate (Daiichi Kogyo Co., Ltd .: Neogen SC), which is an anionic surfactant, is added to the dispersion, heated to 95 ° C., and held for 9 hours to fuse the aggregated particles. I did. Thereafter, it was cooled to 50 ° C. at a descending rate of 0.3 ° C./min, filtered, sufficiently washed with ion exchanged water, and then filtered through a 400 mesh sieve to obtain fused particles. The obtained fused particles were dried by a vacuum drier to obtain toner particles.
To 100 parts by mass of the obtained toner particles, 1.7 parts by mass of hydrophobic silica (Cabot Co., Ltd .: TS720, number average primary particle size 12 nm), 1.7 parts by mass, titanium oxide fine particles surface-treated with isobutyltrimethoxysilane (BET: 80 m 2 / g) 0.2 parts by weight were added. Thereafter, they were mixed by a Henschel mixer to obtain toner 3 having a weight average particle diameter (D4) of 7.6 μm.

<Production of Toner 4>
Toner 4 was obtained in the same manner as in the manufacture of toner 3 except that the amount of hydrophobic silica added was changed to 2.6 parts by mass.

<Production of Toner 5>
In preparation of Toner 3, the release agent in preparation of the release agent dispersion was changed to pentaerythritol behenic acid, and in preparation of the resin fine particle dispersion, the charge control agent was changed to the charge control agent (B) The toner 5 was obtained in the same manner as in the production of the toner 3.

<Production of Toner 6>
In the production of Toner 3, the toner was changed to paraffin wax in the preparation of the dispersion of the release agent, and toner was prepared in the preparation of the dispersion of fine resin particles, except that the charge control agent was changed to the charge control agent (C) Toner 6 was obtained in the same manner as in the preparation of 3.

<Production of Toner 7>
Toner 7 was obtained in the same manner as in the manufacture of toner 3 except that the charge control agent in the preparation of the resin fine particle dispersion was changed to the charge control agent (D) in the preparation of toner 3.

<Manufacture of Toner 8>
Toner 7 was obtained in the same manner as in the preparation of toner 3 except that the charge control agent in the preparation of the resin fine particle dispersion was changed to the charge control agent (B) in the preparation of toner 3.

The manufactured toner is shown in Table 4.

Example 1
The processing speed of commercially available LBP-3100 (manufactured by Canon Inc.) was modified to 150 mm / s and used as an evaluation machine. Further, the product toner was removed from the commercially available black toner cartridge, the inside of the cartridge was cleaned by air blowing, and 80 g of the toner (1) was filled. Thereafter, the electrophotographic photosensitive member mounted on the product was removed, and the electrophotographic photosensitive member (1) was mounted.
In the endurance test, A4 size CLC paper (manufactured by Canon Inc., weighing 80 g / m ² ) was used as a transfer material. A durability test is conducted by stopping 1 minute each time 2 sheets are printed at a printing rate of 1% under normal temperature and humidity conditions (N / N: temperature 23.5 ° C., humidity 60% RH), and after printing 16000 sheets After leaving for 6 days, the first image sample was subjected to fog evaluation.

(Evaluation of fog)
The measurement of fog was performed using REFLECT METER MODELTC-6DS manufactured by Tokyo Denshoku Co., Ltd. The reflectance of the transfer paper before white image formation was also measured after being left for 6 days in the same manner. The filter used was a green filter.
From the reflectance before and after the white image output, fog was calculated using the following equation.
Fog (reflectance) (%) = reflectance of transfer paper (%)-reflectance of white image (%)
The judgment criteria for fogging are as follows. If it is C or more, there is no problem in practical use.
A: less than 1.0% B: 1.0% or more and less than 3.0% C: 3.0% or more and less than 5.0% D: 5.0% or more Evaluation of fog is evaluated as 2 and electrophotographic photosensitive Table 5 shows the combinations of body and toner.

[Examples 2 to 33, Comparative Examples 1 and 2]
The same procedure as in Example 1 was repeated except that the electrophotographic photosensitive member and the toner used in Example 1 were changed as shown in Table 5. The results of the evaluation carried out in the same manner as in Example 1 are shown in Table 5.

DESCRIPTION OF SYMBOLS 1 electrophotographic photosensitive member 2 axis 3 Charging means 4 Exposure light 5 Development means 6 Transfer means 7 Transfer material 8 Fixing means 9 Cleaning means 10 Pre-exposure light 11 Process cartridge 12 Guide means

Claims (13)

A charging member, an electrophotographic photosensitive member contact-charged by the charging member, a developing member for developing a toner image on the electrophotographic photosensitive member to form a toner image, and the toner image on the electrophotographic photosensitive member A transfer member for transferring to a transfer material;
The toner contains toner particles having a binder resin and a charge control agent, and an external additive,
The charge control agent has an azo group-containing chromium complex,
The content of the external additive is 1.7% by mass or more based on the content of the toner particles,
The electrophotographic photosensitive member has a surface layer,
A process cartridge wherein the Martens hardness of the surface layer is 245 N / mm ² or more. The surface layer of the electrophotographic photosensitive member contains a resin,
At least one selected from polyester resins having a structure represented by the general formula (I) and a structure represented by the general formula (II), and a polycarbonate resin having a structure represented by the general formula (III) The process cartridge according to claim 1, wherein
(In the general formula (I), X ¹ represents a single bond, an oxygen atom, an alkylidene group or a cycloalkylidene group. R ^{11 to} R ¹⁸ each independently represent a hydrogen atom or an alkyl group.)
(In the general formula (II), X ² represents a divalent group.)
(In the general formula (III), X ³ represents a single bond, an oxygen atom, an alkylidene group or a cycloalkylidene group. R ^{21 to} R ²⁸ each independently represent a hydrogen atom or an alkyl group.) The resin contained in the surface layer of the electrophotographic photosensitive member is a polyester resin having a structure represented by the general formula (I) and a structure represented by the general formula (II), and is represented by the general formula (I) The process cartridge according to claim 2, wherein the shown structure has a structure shown by the general formula (I-1).
(In the general formula (I-1), R ^{31 to} R ³⁴ each independently represent a hydrogen atom or a methyl group.) From the structure represented by the formula (I-1-1), the formula (I-1-2) and the formula (I-1-3) in the polyester resin, the structure represented by the general formula (I-1) The process cartridge according to claim 3, having at least one selected structure.
The polyester resin is further selected from Formula (I-2-1), Formula (I-2-2), Formula (I-2-3), Formula (I-2-4) and Formula (I-2-5). The process cartridge according to claim 3 or 4, wherein the process cartridge has at least one structure selected from the structures shown in the above.
The process cartridge according to any one of claims 3 to 5, wherein the structure represented by the general formula (II) in the polyester resin has a structure represented by the formula (II-1).
  The polyester resin according to any one of claims 3 to 6, wherein the proportion of the structure represented by the general formula (I-1) in the structure represented by the general formula (I) is 20 mol% or more. Process cartridge described in. The resin contained in the surface layer of the electrophotographic photosensitive member is a polycarbonate resin having the structure represented by the general formula (III), and the structure represented by the general formula (III) is represented by the general formula (III-) The process cartridge according to claim 2 having a structure shown in 1).
(In the general formula (III-1), R ^{41 to} R ⁴⁴ each independently represent a hydrogen atom or a methyl group.) From the structures represented by the formula (III-1-1), the formula (III-1-2) and the formula (III-1-3) in the polycarbonate resin, the structure represented by the general formula (III-1) The process cartridge according to claim 8, having at least one selected structure.
The polycarbonate resin is further selected from Formula (III-2-1), Formula (III-2-2), Formula (III-2-3), Formula (III-2-4) and Formula (III-2-5). The process cartridge according to claim 8 or 9, wherein the process cartridge has at least one structure selected from the structures shown in).
  The composition according to any one of claims 8 to 10, wherein the proportion of the structure represented by the formula (III-1) in the structure represented by the general formula (III) in the polycarbonate resin is 20 mol% or more. Process cartridge.   The process cartridge according to any one of claims 1 to 11, wherein the surface layer of the electrophotographic photosensitive member contains silica particles having a volume average particle diameter of 40 nm or more and 200 nm or less.   An electrophotographic apparatus comprising the process cartridge according to any one of claims 1 to 12.