JP2023161161A - Electrophotographic device and process cartridge - Google Patents

Abstract

To reduce a change in image density in repeated printing.SOLUTION: An electrophotographic photoreceptor includes: a charge transport material; a polycarbonate resin having a structural unit indicated by a formula (1) or a polyester resin having a structural unit indicated by a formula (2); and a surface layer containing a styrene-(meth)acrylate resin, the polycarbonate resin, or the polyester resin each having a siloxane moiety. A toner has a non-crystalline polyester resin, the crystalline polyester resin, and a toner particle containing an inorganic fine particle, and the inorganic fine particle fixed by surface treatment with hot air is present on a surface of the toner particle.SELECTED DRAWING: Figure 2

Description

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

In recent years, electrophotographic devices such as copiers and laser beam printers have been desired to increase the number of printable sheets, improve image quality, and support various paper types.

The electrophotographic process involves forming an electrostatic latent image on the surface of an electrophotographic photoreceptor, developing the electrostatic latent image with toner to form a toner image, and transferring the toner image to a transfer material such as paper. A common process is to fix a toner image on paper using heat or pressure to obtain a printed image. Furthermore, a method is known in which toner remaining on the surface of an electrophotographic photoreceptor without being transferred to a transfer material is removed by a cleaning means having a cleaning blade.

Organic photoreceptors are often used as electrophotographic photoreceptors used in electrophotographic devices.

In an electrophotographic process, toner, a charging member, a transfer member, a cleaning blade, paper, and the like come into contact with the surface of an electrophotographic photoreceptor. Electrophotographic photoreceptors are required to have durability against mechanical deterioration and electrical deterioration due to contact stress with these contacting members. Additionally, as improvements are made to toner, transfer means, cleaning means, etc. in order to accommodate various paper types, the contact stress between these and the electrophotographic photoreceptor may increase. is required to be more durable.

Patent Document 1 describes a technique in which a resin having a biphenyl structure in the molecule is contained in the surface layer of an electrophotographic photoreceptor in order to improve the durability of the electrophotographic photoreceptor against mechanical deterioration and electrical deterioration. There is.

Further, Patent Document 2 discloses a technique in which toner particles contain an amorphous polyester resin and a crystalline polyester resin as a toner with improved low-temperature fixing performance in order to be compatible with various paper types.

Japanese Patent Application Publication No. 2018-049148 Japanese Patent Application Publication No. 2011-123352

According to studies by the present inventors, in an electrophotographic apparatus using the electrophotographic photoreceptor described in Patent Document 1, although the durability against mechanical deterioration of the electrophotographic photoreceptor is improved, toner slips through during the cleaning process. Contamination of the charging member may occur. In addition, image defects or changes in image density during repeated printing may occur. Furthermore, in the electrophotographic apparatus using the toner described in Patent Document 2, there are cases where a change in image density occurs during repeated printing, and there is room for further study.

An object of the present invention is to provide an electrophotographic apparatus and a process cartridge in which the change in image density during repeated printing is small.

The present invention
electrophotographic photoreceptor,
Charging means for charging the surface of the electrophotographic photoreceptor;
image exposure means for irradiating the charged surface of the electrophotographic photoreceptor with image exposure light to form an electrostatic latent image on the surface of the electrophotographic photoreceptor;
a developing means having a toner and for developing the electrostatic latent image formed on the surface of the electrophotographic photoreceptor with the toner to form a toner image on the surface of the electrophotographic photoreceptor;
a transfer means for transferring the toner image formed on the surface of the electrophotographic photoreceptor to a transfer material; and
a cleaning means having a cleaning blade and for removing toner remaining on the surface of the electrophotographic photoreceptor by bringing the cleaning blade into contact with the surface of the electrophotographic photoreceptor;
In an electrophotographic device having
The electrophotographic photoreceptor is
charge transport material,
At least one binder resin selected from the group consisting of a polycarbonate resin having a structural unit represented by the following formula (1) and a polyester resin having a structural unit represented by the following formula (2), and
A siloxane moiety-containing resin selected from the group consisting of a styrene-(meth)acrylate resin having a siloxane moiety, a polycarbonate resin having a siloxane moiety, and a polyester resin having a siloxane moiety;
has a surface layer containing
The toner has toner particles containing an amorphous polyester resin, a crystalline polyester resin, and inorganic fine particles,
The inorganic fine particles fixed by surface treatment with hot air are present on the surface of the toner particles.
This is an electrophotographic device characterized by the following.

(In formula (1), R ¹ to R ⁴ each independently represent a hydrogen atom or a methyl group.)

(In formula (2), R ¹¹ to R ¹⁴ each independently represent a hydrogen atom or a methyl group. Y ¹ is a m-phenylene group, a p-phenylene group, or two p-phenylene groups. (Indicates a divalent group formed by bonding through an oxygen atom.)
Moreover, the present invention
A process cartridge removably attachable to the main body of an electrophotographic apparatus,
The process cartridge is
electrophotographic photoreceptor,
Charging means for charging the surface of the electrophotographic photoreceptor;
a developing means having a toner and for developing an electrostatic latent image formed on the surface of the electrophotographic photoreceptor with the toner to form a toner image on the surface of the electrophotographic photoreceptor;
a cleaning means having a cleaning blade and for removing toner remaining on the surface of the electrophotographic photoreceptor by bringing the cleaning blade into contact with the surface of the electrophotographic photoreceptor;
has
The electrophotographic photoreceptor is
charge transport material,
at least one binder resin selected from the group consisting of a polycarbonate resin having a structural unit represented by the above formula (1) and a polyester resin having a structural unit represented by the above formula (2), and
A siloxane moiety-containing resin selected from the group consisting of a styrene-(meth)acrylate resin having a siloxane moiety, a polycarbonate resin having a siloxane moiety, and a polyester resin having a siloxane moiety;
has a surface layer containing
The toner has toner particles containing an amorphous polyester resin, a crystalline polyester resin, and inorganic fine particles,
The inorganic fine particles fixed by surface treatment with hot air are present on the surface of the toner particles.
This process cartridge is characterized by:

According to the present invention, it is possible to provide an electrophotographic apparatus and a process cartridge in which the change in image density during repeated printing is small.

FIG. 2 is a diagram showing an example of a surface treatment device using hot air. 1 is a diagram illustrating an example of an electrophotographic apparatus.

The electrophotographic apparatus of the present invention includes:
electrophotographic photoreceptor,
charging means for charging the surface of the electrophotographic photoreceptor;
image exposure means for irradiating the charged surface of the electrophotographic photoreceptor with image exposure light to form an electrostatic latent image on the surface of the electrophotographic photoreceptor;
a developing means having a toner and for developing the electrostatic latent image formed on the surface of the electrophotographic photoreceptor with the toner to form a toner image on the surface of the electrophotographic photoreceptor;
a transfer means for transferring the toner image formed on the surface of the electrophotographic photoreceptor to a transfer material; and
a cleaning means having a cleaning blade and for removing toner remaining on the surface of the electrophotographic photoreceptor by bringing the cleaning blade into contact with the surface of the electrophotographic photoreceptor;
In an electrophotographic device having
The electrophotographic photoreceptor is
a charge transport material;
At least one binder resin selected from the group consisting of a polycarbonate resin having a structural unit represented by the following formula (1) and a polyester resin having a structural unit represented by the following formula (2), and
A siloxane moiety-containing resin selected from the group consisting of a styrene-(meth)acrylate resin having a siloxane moiety, a polycarbonate resin having a siloxane moiety, and a polyester resin having a siloxane moiety;
has a surface layer containing
The toner has toner particles containing an amorphous polyester resin, a crystalline polyester resin, and inorganic fine particles,
The inorganic fine particles fixed by surface treatment with hot air are present on the surface of the toner particles.
It is characterized by

(In formula (1), R ¹ to R ⁴ each independently represent a hydrogen atom or a methyl group.)

(In formula (2), R ¹¹ to R ¹⁴ each independently represent a hydrogen atom or a methyl group. Y ¹ is a m-phenylene group, a p-phenylene group, or two p-phenylene groups. (Indicates a divalent group formed by bonding through an oxygen atom.)
Furthermore, the process cartridge of the present invention includes:
A process cartridge removably attachable to the main body of an electrophotographic apparatus,
The process cartridge is
electrophotographic photoreceptor,
Charging means for charging the surface of the electrophotographic photoreceptor;
a developing means having a toner and for developing an electrostatic latent image formed on the surface of the electrophotographic photoreceptor with the toner to form a toner image on the surface of the electrophotographic photoreceptor;
a cleaning means having a cleaning blade and for removing toner remaining on the surface of the electrophotographic photoreceptor by bringing the cleaning blade into contact with the surface of the electrophotographic photoreceptor;
has
The electrophotographic photoreceptor is
charge transport material,
at least one binder resin selected from the group consisting of a polycarbonate resin having a structural unit represented by the above formula (1) and a polyester resin having a structural unit represented by the above formula (2), and
A siloxane moiety-containing resin selected from the group consisting of a styrene-(meth)acrylate resin having a siloxane moiety, a polycarbonate resin having a siloxane moiety, and a polyester resin having a siloxane moiety;
has a surface layer containing
The toner has toner particles containing an amorphous polyester resin, a crystalline polyester resin, and inorganic fine particles,
The inorganic fine particles fixed by surface treatment with hot air are present on the surface of the toner particles.
It is characterized by

The structural unit represented by the above formula (1) and the structural unit represented by the above formula (2) have a biphenyl structure.

By incorporating the above-mentioned binder resin having a biphenyl structure into the surface layer of the electrophotographic photoreceptor, the durability of the electrophotographic photoreceptor can be improved.

Further, by incorporating the above-mentioned siloxane moiety-containing resin into the surface layer of the electrophotographic photoreceptor, it is possible to reduce friction between the cleaning blade and the toner that come into contact with the surface of the electrophotographic photoreceptor. Therefore, contamination of the charging member due to toner slipping through during the cleaning process is suppressed, and image defects and changes in image density during repeated printing are suppressed. Further, the above-mentioned siloxane moiety-containing resin has good compatibility with the above-mentioned binder resin having a biphenyl structure, and can suppress a decrease in sensitivity of the electrophotographic photoreceptor due to repeated printing.

By incorporating amorphous polyester resin, crystalline polyester resin, and inorganic fine particles into the toner particles of the toner, and fixing the inorganic fine particles by surface treatment with hot air, the charging stability of the toner is improved, and the image quality during repeated printing is improved. Changes in concentration are suppressed.

[Electrophotographic photoreceptor]
As a method for producing an electrophotographic photoreceptor, there is a method of preparing a coating solution for each layer as described below, applying the coating solution to the desired layers in order to form a coating film, and drying and/or curing the coating film. Can be mentioned. Examples of methods for applying the coating liquid include dip coating, spray coating, inkjet coating, roll coating, die coating, blade coating, curtain coating, wire bar coating, and ring coating. Among these, dip coating is preferred from the viewpoint of efficiency and productivity.

The support and each layer will be explained below.

<Support>
Electrophotographic photoreceptors generally have a support. The support is preferably one having electrical conductivity (conductive support). Further, the shape of the support includes a cylindrical shape, a belt shape, a sheet shape, and the like. Among these, cylindrical supports are preferred. Further, the surface of the support may be subjected to electrochemical treatment such as anodization, blasting treatment, cutting treatment, or the like.

Examples of the material of the support include metal, resin, and glass. Examples of metals include aluminum, iron, nickel, copper, gold, stainless steel, and alloys thereof. Among these, aluminum supports made of aluminum or aluminum alloys are preferred.

Further, conductivity may be imparted to the resin support or glass support by mixing and/or coating with a conductive material.

<Conductive layer>
A conductive layer may be provided between the support and the photosensitive layer (charge generation layer). By providing a conductive layer, it is possible to hide 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 resin.

Examples of the material for 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 metals include aluminum, nickel, iron, nichrome (an alloy of nickel and chromium), copper, zinc, and silver. Among these, metal oxides are preferred, and titanium oxide, tin oxide, and zinc oxide are more preferred.

When using metal oxide particles as conductive particles, the surface of the metal oxide particles may be treated with a silane coupling agent, or the metal oxide particles may be doped with elements such as phosphorus or aluminum or their oxides. Good too.

The conductive particles may have a laminated structure including core particles and a coating layer covering the core particles. Examples of the material of the core particles include titanium oxide, barium sulfate, zinc oxide, and the like. Examples of the material for the coating layer include metal oxides such as tin oxide.

When using metal oxide particles as the conductive particles, the volume average particle diameter of the metal oxide particles 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.

The conductive layer may further contain a masking agent such as silicone oil, resin particles, titanium oxide particles, and the like.

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

The conductive layer is formed by preparing a conductive layer coating solution containing each of the above-mentioned materials and a solvent, applying the conductive layer coating solution to form a coating film, and drying and/or curing the coating film. be able to.

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

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

<Undercoat layer>
An undercoat layer may be provided between the support or conductive layer and the photosensitive layer (charge generation layer). By providing an undercoat layer, it is possible to enhance the adhesion function between layers and provide a charge injection blocking function.

It is preferable that the undercoat layer contains resin. Further, the undercoat layer may be a cured film obtained by polymerizing a composition containing a monomer having a polymerizable functional group.

Examples of resins include 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, and polyamide resin. , polyamic acid resin, polyimide resin, polyamideimide resin, cellulose resin and the like.

Examples of the polymerizable functional group of the monomer having a 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, an amino group, a carboxyl group, a thiol group, Examples include carboxylic acid anhydride groups and carbon-carbon double bond groups.

The undercoat layer may further contain an electron transport material, metal oxide particles, metal particles, conductive polymer, etc. for the purpose of improving electrical properties. Among these, electron transport substances and metal oxide particles are preferred.

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 electron transporting monomer having a polymerizable functional group is used as the electron transporting substance, and by polymerizing it or copolymerizing it with another monomer having a polymerizable functional group, an undercoat layer can be formed as a cured film. may be formed.

Examples of the material of the metal oxide particles include tin oxide, indium oxide, titanium oxide, zinc oxide, aluminum oxide, silicon dioxide, strontium titanate, and calcium titanate. The surface of the metal oxide particles may be treated with a silane coupling agent or the like, or the metal oxide particles may be doped with elements such as phosphorus, aluminum, niobium, or oxides thereof.

Moreover, the undercoat layer may further contain other additives.

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

The undercoat layer is prepared by preparing an undercoat layer coating solution containing each of the above-mentioned materials and a solvent, applying the undercoat layer coating solution to form a coating film, and drying and/or curing the coating film. can be formed with.

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

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

(1) Laminated photosensitive layer The laminated photosensitive layer has a charge generation layer and a charge transport layer.

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

Examples of the charge generating substance include azo pigments, perylene pigments, polycyclic quinone pigments, indigo pigments, and phthalocyanine pigments. Among these, azo pigments and phthalocyanine pigments are preferred. Among the phthalocyanine pigments, oxytitanium phthalocyanine pigments, chlorogallium phthalocyanine pigments, and hydroxygallium phthalocyanine pigments are preferred.

The content of the charge generating substance in the charge generating layer is preferably 40% by mass or more and 85% by mass or less, more preferably 60% by mass or more and 80% by mass or less, based on the total mass of the charge generating layer. preferable.

The charge generation layer may further contain additives such as antioxidants and ultraviolet absorbers. Examples of additives include hindered phenol compounds, hindered amine compounds, sulfur compounds, phosphorus compounds, and benzophenone compounds.

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

The charge generation layer can be formed by preparing a charge generation layer coating solution containing each of the above-mentioned materials and a solvent, applying the charge generation layer coating solution to form a coating film, and drying the coating film. I can do it.

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

Examples of the charge transport substance include polycyclic aromatic compounds, heterocyclic compounds, hydrazone compounds, styryl compounds, enamine compounds, benzidine compounds, triarylamine compounds, and resins having groups derived from these substances. Among these, from the viewpoint of improving memory, it is preferable to contain at least one compound selected from the group consisting of the compound represented by the following formula (7) and the compound represented by the following formula (8) as a charge transport substance. preferable.

The content of the charge transport substance in the charge transport layer is preferably 25% by mass or more and 70% by mass or less, more preferably 30% by mass or more and 55% by mass or less, based on the total mass of the charge transport layer. preferable.

Examples of the resin include polyester resin and polycarbonate resin. As the polyester resin, polyarylate resin is preferable.

The content ratio of the charge transport substance and resin in the charge transport layer (charge transport substance:resin, mass ratio) is preferably 4:10 to 20:10, and preferably 5:10 to 12:10. More preferred.

The charge transport layer may further contain additives such as antioxidants, ultraviolet absorbers, plasticizers, and leveling agents. Specific examples include hindered phenol compounds, hindered amine compounds, sulfur compounds, phosphorus compounds, benzophenone compounds, fluororesin particles, polystyrene resin particles, polyethylene resin particles, silica particles, alumina particles, and boron nitride particles.

The thickness of the charge transport layer is preferably 3 μm or more and 50 μm or less, more preferably 5 μm or more and 50 μm or less.

The charge transport layer can be formed by preparing a charge transport layer coating solution containing each of the above-mentioned materials and a solvent, applying the charge transport layer coating solution to form a coating film, and drying the coating film. I can do it. Examples of the solvent used in the charge transport layer coating solution include alcohol solvents, ketone solvents, ether solvents, ester solvents, and aromatic hydrocarbon solvents. Among these, ether solvents and aromatic hydrocarbon solvents are preferred. Furthermore, it is particularly preferable to combine a low boiling point solvent and a high boiling point solvent from among orthoxylene, toluene, tetrahydrofuran, methylal, methyl benzoate, and cyclopentanone.

(2) Single-layer photosensitive layer A single-layer photosensitive layer is prepared by preparing a coating solution for a single-layer photosensitive layer containing a charge-generating substance, a charge-transporting substance, a resin, and a solvent. It can be formed by coating to form a coating film and drying the coating film. As the charge generating substance, the charge transporting substance, and the resin, the same materials as in the above "(1) Laminated photosensitive layer" can be mentioned.

<Surface layer>
In the present invention, the surface layer of the electrophotographic photoreceptor is as described above.
charge transport material,
at least one binder resin selected from the group consisting of a polycarbonate resin having a structural unit represented by the above formula (1) and a polyester resin having a structural unit represented by the above formula (2), and
A siloxane moiety-containing resin selected from the group consisting of a styrene-(meth)acrylate resin having a siloxane moiety, a polycarbonate resin having a siloxane moiety, and a polyester resin having a siloxane moiety;
Contains.

That is, since the surface layer of the electrophotographic photoreceptor according to the present invention contains a charge transporting substance, when the photosensitive layer is a laminated type photoreceptor, the charge transport layer is the surface layer of the electrophotographic photoreceptor, and the photosensitive layer When is a single-layer type photosensitive layer, the single-layer type photosensitive layer is the surface layer of the electrophotographic photoreceptor.

Specific examples of the structural unit represented by the above formula (1) are shown below.

Specific examples of the structural unit represented by the above formula (2) are shown below.

It is preferable that the polycarbonate resin having a structural unit represented by the above formula (1) further has a structural unit represented by the following formula (3). The molar ratio ((1):(3), copolymerization ratio) of the structural unit represented by the above formula (1) and the structural unit represented by the following formula (3) is determined by the durability of the electrophotographic photoreceptor and the solvent of the resin. From the viewpoint of solubility in , the ratio is preferably 5:5 to 1:9. The copolymerization form may be any form such as block copolymerization, random copolymerization, or alternating copolymerization.

It is more preferable that the polyester resin having a structural unit represented by the above formula (2) further has a structural unit represented by the following formula (4). The molar ratio ((2):(4), copolymerization ratio) of the structural unit represented by the above formula (2) and the structural unit represented by the following formula (4) is determined by the durability of the electrophotographic photoreceptor and the solvent of the resin. From the viewpoint of solubility in , the ratio is preferably 5:5 to 1:9. The copolymerization form may be any form such as block copolymerization, random copolymerization, or alternating copolymerization.

(In formula (3), R ⁵ to R ^{8 each} independently represent a hydrogen atom or a methyl group. Indicates a methylene group, a cyclohexylidene group, or an oxygen atom having a monovalent group as a substituent.)

(In formula (4), R ¹⁵ to R ¹⁸ each independently represent a hydrogen atom or a methyl ^group . ^Y2 represents a methylene group, a cyclohexylidene group, or an oxygen atom having a monovalent group as a substituent. (Indicates a divalent group bonded via a
Specific examples of the structural unit represented by the above formula (3) are shown below.

Specific examples of the structural unit represented by the above formula (4) are shown below.

Polycarbonate resins and polyester resins can be synthesized by known methods such as the phosgene method and the method described in JP-A-2007-047655.

The weight average molecular weight of the polycarbonate resin and polyester resin is preferably 20,000 or more and 300,000 or less, and 30,000 or more and 200,000 or less, from the viewpoint of the durability of the electrophotographic photoreceptor and the coating properties of the coating liquid. It is more preferable that

The siloxane site-containing resin preferably has a structure represented by the following formula (5) and/or a structural unit represented by the following formula (6) as the siloxane site.

(In formula (5), a and b indicate the average number of repeats of the structure in parentheses. a is 10 or more and 100 or less. b is 1 or more and 10 or less.)

(In formula (6), c, d, and e each independently indicate the average value of the number of repeats of the structure in parentheses. c and e each independently range from 1 to 10. d is (10 or more and 100 or less)
Specific examples of the monovalent group having the structure represented by the above formula (5) are shown below.

Specific examples of the structural unit represented by the above formula (6) are shown below.

The styrene-(meth)acrylate resin having a siloxane moiety is preferably a resin having a structural unit having a siloxane structure and a (meth)acrylate structure represented by the above formula (5), and a structural unit having a styrene structure. .

The styrene (meth)acrylate resin having a siloxane moiety can be synthesized by a known method such as the method described in JP-A-58-167606 or the method described in JP-A-62-75462. .

Specific examples of styrene-(meth)acrylate resins having siloxane moieties are shown below.

A polycarbonate resin having a siloxane moiety and a polyester resin having a siloxane moiety have a siloxane structure represented by the above formula (5) at the end and/or a structural unit represented by the above formula (6) in the main chain. It is preferable. Moreover, it is preferable that the polycarbonate resin having a siloxane moiety has a structural unit represented by the above formula (3). The polyester resin having a siloxane moiety preferably has a structural unit represented by the above formula (4).

A polycarbonate resin having a siloxane structure and a polyester resin having a siloxane structure can be synthesized by a known method such as the method described in JP-A-2007-199688.

Specific examples of polycarbonate resins and polyester resins having siloxane moieties are shown below.

The weight average molecular weight of the siloxane moiety-containing resin is preferably 10,000 or more and 120,000 or less. The weight average molecular weight is a polystyrene equivalent weight average molecular weight measured by the method described in JP-A-2007-79555.

The copolymerization ratio of the siloxane moiety-containing resin can be confirmed by a conversion method using the peak area ratio of hydrogen atoms determined by ¹ H-NMR measurement of the resin.

The content of the siloxane site-containing resin in the surface layer is preferably 0.1% by mass or more and 5.0% by mass or less based on the binder resin of the surface layer. If it is 0.1% by mass or more, the cleaning stability effect is excellent, and if it is 5.0% by mass or less, it is excellent in the effect of suppressing changes in image density during repeated printing.

[toner]
In the present invention, the toner has toner particles containing a crystalline polyester resin, an amorphous polyester resin, and inorganic fine particles, and the inorganic fine particles are fixed to the surface of the toner particles by surface treatment with hot air. By adopting such a configuration, detachment of the inorganic fine particles from the toner particles can be suppressed, and changes in image density during repeated printing can be suppressed.

Examples of the inorganic fine particles that are fixed to the surface of the toner particles include silica fine particles, titanium oxide fine particles, and aluminum oxide fine particles. The inorganic fine particles are preferably hydrophobized with a silane compound, silicone oil, a mixture thereof, or the like.

As the inorganic fine particles for improving the fluidity of the toner, inorganic fine particles having a specific surface area of 50 m ² /g or more and 400 m ² /g or less are preferable. In order to stabilize the durability of the toner, the inorganic fine particles preferably have a specific surface area of 10 m ² /g or more and 50 m ² /g or less. In order to simultaneously improve the fluidity and stabilize the durability of the toner, inorganic fine particles having a specific surface area within the above range may be used in combination.

The amount of inorganic fine particles fixed to the surface of the toner particles is preferably 0.1 parts by mass or more and 10.0 parts by mass or less, based on 100 parts by mass of the toner particles.

The toner particles contain an amorphous polyester resin as a binder resin. Amorphous polyester resins are preferable from the viewpoints of low-temperature fixability and chargeability control of the toner.

Monomers used in the production of polyester resin include polyhydric alcohols (dihydric or trihydric or higher hydric alcohols), polyhydric carboxylic acids (divalent or trivalent or higher hydric carboxylic acids), their acid anhydrides, and their acid anhydrides. and lower alkyl esters.

Examples of dihydric alcohols include ethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, diethylene glycol, triethylene glycol, 1,5-pentanediol, 1,6 -hexanediol, neopentyl glycol, 2-ethyl-1,3-hexanediol, hydrogenated bisphenol A, bisphenol and its derivatives.

Trivalent or higher alcohol components include sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4-butanetriol, 1 , 2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxymethylbenzene, etc. It will be done. Among these, glycerol, trimethylolpropane, and pentaerythritol are preferred.

Only one type of dihydric alcohol and trihydric or higher alcohol can be used, or two or more types can be used in combination.

Divalent carboxylic acid components include maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, malonic acid, n- Dodecenylsuccinic acid, isododecenylsuccinic acid, n-dodecylsuccinic acid, isododecylsuccinic acid, n-octenylsuccinic acid, n-octylsuccinic acid, isooctenylsuccinic acid, isooctylsuccinic acid, anhydrides of these acids, these Examples include lower alkyl esters. Among these, maleic acid, fumaric acid, terephthalic acid, n-dodecenylsuccinic acid and the like are preferred.

Examples of trivalent or higher carboxylic acids, their acid anhydrides, and their lower alkyl esters include 1,2,4-benzenetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, and 1,2,4-naphthalenetricarboxylic acid. , 1,2,4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methyl-2-methylenecarboxypropane, 1,2,4-cyclohexanetricarboxylic acid, tetra( (methylenecarboxyl)methane, 1,2,7,8-octane tetracarboxylic acid, pyromellitic acid, empol trimer acid, acid anhydrides thereof, lower alkyl esters thereof, and the like. Among these, trimellitic acid (1,2,4-benzenetricarboxylic acid) and trimellitic acid derivatives are preferred because they are inexpensive and easy to control the reaction.

Only one kind of divalent carboxylic acid and trivalent or higher carboxylic acid can be used, or two or more kinds can be used in combination.

The polyester resin may be a hybrid resin containing a polyester portion as a main component. Examples of the hybrid resin include hybrid resins having a polyester part and a vinyl polymer part. A method for producing a hybrid resin includes a method of polymerizing a monomer capable of reacting with a vinyl polymer or polyester (a monomer capable of forming a polyester or a monomer capable of forming a vinyl polymer) in the presence of the vinyl polymer or polyester.

Among the monomers that can constitute the polyester resin, those that can react with the vinyl polymer include unsaturated dicarboxylic acids such as phthalic acid, maleic acid, citraconic acid, and itaconic acid, and their anhydrides. Among the monomers that can constitute the vinyl polymer, those that can react with polyester include those having a carboxy group or hydroxyl group, acrylic esters, methacrylic esters, and the like.

The toner particles may contain a resin other than the amorphous polyester resin. Resins other than amorphous polyester resin include phenol resin, natural resin-modified phenol resin, natural resin-modified maleic resin, acrylic resin, methacrylic resin, polyvinyl acetate resin, silicone resin, polyurethane resin, polyamide resin, furan resin, and epoxy. Examples include resins, xylene resins, polyvinyl butyral resins, terpene resins, coumaroindene resins, and petroleum-based resins.

As the amorphous polyester resin, a low molecular weight amorphous polyester resin L and a high molecular weight amorphous polyester resin H may be used in combination. The mixing ratio (H/L, mass ratio) of high molecular weight amorphous polyester resin H and low molecular weight amorphous polyester resin L is 10/90 or more from the viewpoint of low temperature fixability and hot offset resistance of the toner. It is preferable that it is 60/40 or less.

The peak molecular weight of the high molecular weight amorphous polyester resin H is preferably 10,000 or more and 20,000 or less from the viewpoint of hot offset resistance of the toner. The acid value of the high molecular weight amorphous polyester resin H is preferably 2 mgKOH/g or more and 20 mgKOH/g or less from the viewpoint of charging stability of the toner in a high temperature and high humidity environment.

The peak molecular weight of the low molecular weight amorphous polyester resin L is preferably 3,000 or more and 7,000 or less from the viewpoint of low-temperature fixability of the toner. The acid value of the low molecular weight amorphous polyester resin is preferably 10 mgKOH/g or less from the viewpoint of charging stability of the toner in a high temperature and high humidity environment.

The toner particles contain crystalline polyester resin. By containing the crystalline polyester resin in the toner particles, it becomes easier to plasticize the polyester resin as the binder resin of the toner particles, and the low-temperature fixability of the toner can be improved.

Crystalline polyester resins are obtained by subjecting aliphatic diols and aliphatic dicarboxylic acids to a polycondensation reaction. It is preferable that the aliphatic diol and the aliphatic dicarboxylic acid each have 6 or more and 12 or less carbon atoms.

As the aliphatic diol, a chain aliphatic diol is preferred, and a linear aliphatic diol is more preferred. Examples of aliphatic diols include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, dipropylene glycol, 1,4-butanediol, 1,4-butadiene glycol, and trimethylene glycol. , tetramethylene glycol, pentamethylene glycol, hexamethylene glycol, octamethylene glycol, nonamethylene glycol, decamethylene glycol, neopentyl glycol, and the like. Among these, linear aliphatic diols such as ethylene glycol, diethylene glycol, 1,4-butanediol, and 1,6-hexanediol, and α,ω-diols are preferred.

Of the alcohol component, 50% by mass or more is preferably an aliphatic diol having 6 or more and 12 or less carbon atoms, and more preferably 70% by mass or more is an aliphatic diol having 6 or more and 12 or less carbon atoms.

Polyhydric alcohols other than aliphatic diols can also be used. Examples of dihydric alcohols among polyhydric alcohols include aromatic alcohols such as polyoxyethylenated bisphenol A and polyoxypropylenated bisphenol A, and 1,4-cyclohexanedimethanol. Among polyhydric alcohols, trivalent or higher polyhydric alcohols include aromatic alcohols such as 1,3,5-trihydroxymethylbenzene, pentaerythritol, dipentaerythritol, tripentaerythritol, and 1,2,4-butane. Examples include aliphatic alcohols such as triol, 1,2,5-pentanetriol, glycerin, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, and trimethylolpropane.

A monohydric alcohol may be used to the extent that the properties of the crystalline polyester resin are not impaired. Examples of the monohydric alcohol include n-butanol, isobutanol, sec-butanol, n-hexanol, n-octanol, lauryl alcohol, 2-ethylhexanol, decanol, cyclohexanol, benzyl alcohol, and dodecyl alcohol.

As the aliphatic dicarboxylic acid, a chain aliphatic dicarboxylic acid is preferable, and a linear aliphatic dicarboxylic acid is more preferable. Aliphatic dicarboxylic acids include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, superic acid, glutaconic acid, azelaic acid, sebacic acid, nonanedicarboxylic acid, decanedicarboxylic acid, undecanedicarboxylic acid, and dodecane. Examples include dicarboxylic acid, maleic acid, fumaric acid, mesaconic acid, citraconic acid, itaconic acid, and the like. Also included are those obtained by hydrolyzing these acid anhydrides and lower alkyl esters.

Of the carboxylic acid components, 50% by mass or more is preferably dicarboxylic acid having 6 to 12 carbon atoms, and more preferably 70% by mass or more is dicarboxylic acid having 6 to 12 carbon atoms.

Polyhydric carboxylic acids other than aliphatic dicarboxylic acids can also be used. Divalent carboxylic acids among polyhydric carboxylic acids include aromatic carboxylic acids such as isophthalic acid and terephthalic acid, aliphatic carboxylic acids such as n-dodecylsuccinic acid and n-dodecenylsuccinic acid, and cyclohexanedicarboxylic acid. Examples include alicyclic carboxylic acids. Also included are acid anhydrides and lower alkyl esters thereof. In addition, among the polyvalent carboxylic acids, polyvalent carboxylic acids having a valence of 3 or more include 1,2,4-benzenetricarboxylic acid (trimellitic acid), 2,5,7-naphthalenetricarboxylic acid, 1,2,4- Aromatic carboxylic acids such as naphthalenetricarboxylic acid and pyromellitic acid, 1,2,4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, and 1,3-dicarboxyl-2-methyl-2-methylenecarboxylic acid. Examples include aliphatic carboxylic acids such as propane. Also included are derivatives of these acid anhydrides, lower alkyl esters, and the like.

A monovalent carboxylic acid may be used to the extent that the properties of the crystalline polyester resin are not impaired. Monovalent carboxylic acids include benzoic acid, naphthalenecarboxylic acid, salicylic acid, 4-methylbenzoic acid, 3-methylbenzoic acid, phenoxyacetic acid, biphenylcarboxylic acid, acetic acid, propionic acid, butyric acid, octanoic acid, decanoic acid, and dodecane. acid, stearic acid, etc.

The crystalline polyester resin can be manufactured by a known polyester resin synthesis method. For example, a crystalline polyester resin can be produced by subjecting a carboxylic acid and an alcohol to an esterification reaction or transesterification reaction, followed by a polycondensation reaction under reduced pressure or by introducing nitrogen gas. The esterification reaction or transesterification reaction can also be carried out using an esterification or transesterification catalyst such as sulfuric acid, titanium butoxide, dibutyltin oxide, manganese acetate, or magnesium acetate. The polycondensation reaction can also be carried out using a catalyst such as titanium butoxide, dibutyltin oxide, tin acetate, zinc acetate, tin disulfide, antimony trioxide, germanium dioxide, or the like. The polymerization temperature and the amount of catalyst are not particularly limited.

In esterification, transesterification, and polycondensation reactions, all monomers may be added at once in order to increase the strength of the crystalline polyester resin produced. Furthermore, in order to reduce the amount of low molecular weight components contained in the crystalline polyester resin to be produced, a divalent monomer may be reacted first, and then a trivalent or higher monomer may be added and reacted.

The content of the crystalline polyester resin in the toner particles is preferably 1.0 parts by mass or more and 15 parts by mass or less, based on 100 parts by mass of the amorphous polyester resin in the toner particles. If the amount is 1.0 parts by mass or more, an excellent plasticizing effect can be obtained and excellent low-temperature fixing properties can be obtained. When the amount is 15 parts by mass or less, adsorption of moisture to the toner is suppressed, so excellent color stability can be obtained.

The acid value of the crystalline polyester resin is preferably 2 mgKOH/g or more and 20 mgKOH/g or less from the viewpoint of suppressing moisture adsorption to the toner.

Preferably, the toner particles contain wax. Examples of waxes include the following:

Hydrocarbon waxes such as low molecular weight polyethylene, low molecular weight polypropylene, alkylene copolymers, microcrystalline wax, paraffin wax, Fischer-Tropsch wax, oxides of hydrocarbon waxes such as oxidized polyethylene wax, or block copolymers thereof Waxes mainly composed of fatty acid esters such as carnauba wax, waxes that have partially or fully deoxidized fatty acid esters such as deoxidized carnauba wax, and saturated straight chain fatty acids such as palmitic acid, stearic acid, and montanic acid. unsaturated fatty acids such as brassicic acid, eleostearic acid, and valinaric acid; saturated alcohols such as stearyl alcohol, aralkyl alcohol, behenyl alcohol, carnaubil alcohol, seryl alcohol, and mericyl alcohol; and polyhydric alcohols such as sorbitol. and esters of fatty acids such as palmitic acid, stearic acid, behenic acid, and montanic acid with alcohols such as stearyl alcohol, aralkyl alcohol, behenyl alcohol, carnaubil alcohol, seryl alcohol, and mericyl alcohol, linoleic acid amide, and oleic acid. Fatty acid amides such as amide, lauric acid amide, saturated fatty acid bisamides such as methylene bis stearic acid amide, ethylene bis capric acid amide, ethylene bis lauric acid amide, hexamethylene bis stearic acid amide, ethylene bis oleic acid amide, hexamethylene Unsaturated fatty acid amides such as bisoleic acid amide, N,N'-dioleyladipic acid amide, N,N'-dioleylsebacic acid amide, m-xylene bisstearic acid amide, N,N'-distearylisophthal Aromatic bisamides such as acid amides, aliphatic metal salts (generally called metal soaps) such as calcium stearate, calcium laurate, zinc stearate, and magnesium stearate, and aliphatic hydrocarbon waxes such as styrene and Wax grafted with vinyl monomers such as acrylic acid, partial esterification products of fatty acids and polyhydric alcohols such as behenic acid monoglyceride, and methyl ester compounds with hydroxyl groups obtained by hydrogenation of vegetable oils and fats. .

Among waxes, hydrocarbon waxes such as paraffin wax and Fischer-Tropsch wax are preferred from the viewpoint of improving the low-temperature fixability of the toner and suppressing the wrapping of paper around the fixing member during fixing.

The content of wax in the toner particles is preferably 0.5 parts by mass or more and 20 parts by mass or less based on 100 parts by mass of the amorphous polyester resin. From the perspective of achieving both toner storage stability and high-temperature offset performance, the maximum endothermic peak that exists in the temperature range of 30°C or higher and 200°C or lower in the endothermic curve during temperature rise measured by a differential scanning calorimeter (DSC) is A wax having a peak temperature of 50°C or higher and 110°C or lower is preferred.

The toner particles preferably contain a wax dispersant in order to improve blocking resistance and hot offset resistance.

As the wax dispersant, a polyolefin graft-modified with a styrene-acrylic polymer is preferred. The styrene acrylic polymer preferably has a unit derived from cycloalkyl (meth)acrylate. Examples of polyolefins include hydrocarbon waxes such as polyethylene, polypropylene, alkylene copolymers, microcrystalline waxes, paraffin waxes, and Fischer-Tropsch waxes. A polyolefin having a peak temperature of the largest thermal peak measured using a differential scanning calorimeter (DSC) of 70° C. or higher and 90° C. or lower is preferred.

As the unit derived from cycloalkyl (meth)acrylate, a unit having a saturated alicyclic hydrocarbon group is preferable. Saturated alicyclic hydrocarbon groups include cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, t-butylcyclohexyl group, cycloheptyl group, cyclooctyl group, tricyclodecanyl group, decahydro-2-naphthyl group, Examples include tricyclo[5.2.1.02,6]decane-8-yl group, pentacyclopentadecanyl group, isobornyl group, adamantyl group, dicyclopentanyl group, and tricyclopentanyl group. The saturated alicyclic hydrocarbon group may have an alkyl group, a halogen atom, a carboxy group, a carbonyl group, a hydroxy group, etc. as a substituent.

The weight average molecular weight of the wax dispersant is preferably 5,000 or more and 70,000 or less. When the weight average molecular weight is 5,000 or more, the wax dispersant tends to remain in the toner particles, and even if the toner is left under high temperature and high humidity, the elution of wax to the surface of the toner is suppressed, and the blocking resistance of the toner is reduced. Improves sex. When the weight average molecular weight is 70,000 or less, wax dispersed in toner particles during fixing can quickly migrate to the surface of the molten toner, improving releasability during fixing and improving high-temperature offset resistance.

Toner particles typically contain a colorant. As the coloring agent, the following may be mentioned.

Examples of the black colorant include carbon black, and a color toned to black using a yellow colorant, a magenta colorant, and a cyan colorant.

Examples of pigments among magenta colorants include the following. C. I. Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 30, 31, 32, 37, 38, 39, 40, 41, 48:2, 48:3, 48:4, 49, 50, 51, 52, 53, 54, 55, 57:1, 58, 60, 63, 64, 68,81:1,83,87,88,89,90,112,114,122,123,146,147,150,163,184,202,206,207,209,238,269,282,C ．． I. Pigment Violet 19, C. I. Bat Red 1, 2, 10, 13, 15, 23, 29, 35.

Examples of dyes among magenta colorants include the following. C. I. Solvent Red 1, 3, 8, 23, 24, 25, 27, 30, 49, 81, 82, 83, 84, 100, 109, 121, C.I. I. Dispersed Red 9, C. I. Solvent Violet 8, 13, 14, 21, 27, C.I. I. Oil-soluble dyes such as Disper Violet 1, C.I. I. Basic Red 1, 2, 9, 12, 13, 14, 15, 17, 18, 22, 23, 24, 27, 29, 32, 34, 35, 36, 37, 38, 39, 40, C. I. Basic dyes such as Basic Violet 1, 3, 7, 10, 14, 15, 21, 25, 26, 27, 28.

Examples of pigments among cyan colorants include the following. C. I. Pigment Blue 2, 3, 15:2, 15:3, 15:4, 16, 17, C. I. Bat Blue 6, C. I. Acid Blue 45, a copper phthalocyanine pigment in which the phthalocyanine skeleton is substituted with 1 to 5 phthalimidomethyl groups.

Among the cyan colorants, C.I. I. Solvent Blue 70 is mentioned.

Examples of pigments among yellow colorants include the following. C. I. Pigment Yellow 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, 15, 16, 17, 23, 62, 65, 73, 74, 83, 93, 94, 95, 97, 109, 110, 111, 120, 127, 128, 129, 147, 151, 154, 155, 168, 174, 175, 176, 180, 181, 185, and C. I. Bat yellow 1, 3, 20.

Among the yellow colorants, C.I. I. Solvent Yellow 162 is mentioned.

As the coloring agent, a pigment may be used alone, or a dye and a pigment may be used in combination. When a dye and a pigment are used in combination, the clarity tends to improve, which is preferable from the viewpoint of the image quality of a full-color image.

The content of the colorant in the toner particles is preferably 0.1 parts by mass or more and 30 parts by mass or less based on 100 parts by mass of the amorphous polyester resin.

The toner may contain a charge control agent. As the charge control agent, metal compounds of aromatic carboxylic acids are preferred from the viewpoints of being colorless or nearly colorless, charging the toner quickly, and stably maintaining the amount of charge.

Examples of negative charge control agents include salicylic acid metal compounds, naphthoic acid metal compounds, dicarboxylic acid metal compounds, polymer compounds with sulfonic acid or carboxylic acid in the side chain, and sulfonate or sulfonic acid ester compounds in the side chain. Examples include polymeric compounds, polymeric compounds having carboxylates or carboxylic acid esters in their side chains, boron compounds, urea compounds, silicon compounds, calixarene, and the like.

The charge control agent may be added internally or externally to the toner particles.

The content of the charge control agent in the toner is preferably 0.2 parts by mass or more and 10 parts by mass or less, based on 100 parts by mass of the amorphous polyester resin in the toner particles.

In the toner according to the present invention, inorganic fine particles are fixed to the surface of the toner particles, but external additives may be further added.

As the external additive, inorganic fine particles such as silica fine particles, titanium oxide fine particles, and aluminum oxide fine particles are preferable. The inorganic fine particles are preferably hydrophobized with a silane compound, silicone oil, a mixture thereof, or the like.

As the inorganic fine particles for improving the fluidity of the toner, inorganic fine particles having a specific surface area of 50 m ² /g or more and 400 m ² /g or less are preferable. As the inorganic fine particles for stabilizing the durability of the toner, inorganic fine particles having a specific surface area of 10 m ² /g or more and 50 m ² /g or less are preferable. In order to simultaneously improve the fluidity and stabilize the durability of the toner, two or more types of inorganic fine particles having a specific surface area within the above range may be used in combination.

The content of the external additive in the toner is preferably 0.1 parts by mass or more and 10.0 parts by mass or less based on 100 parts by mass of toner particles.

A known mixer such as a Henschel mixer can be used to mix the toner particles and the external additive.

As a method for manufacturing the toner, a manufacturing method including a step of performing surface treatment with hot air is preferred. The inorganic fine particles can be fixed to the surface of the toner particles by surface treatment with hot air. A method for producing toner using a pulverization method will be described below.

In the raw material mixing step, toner raw materials such as amorphous polyester resin, crystalline polyester resin, wax, wax dispersant, colorant, charge control agent, and the like are weighed and mixed. Mixing devices include Henschel mixer (manufactured by Nippon Coke Co., Ltd.), Super Mixer (manufactured by Kawata Co., Ltd.), Ribocorn (manufactured by Okawara Seisakusho Co., Ltd.), Nauta Mixer, Turbulizer, Cyclomix (manufactured by Hosokawa Micron Co., Ltd.), Spiral Pin Mixer (manufactured by Hosokawa Micron Co., Ltd.) (manufactured by Taiheiyo Kiko Co., Ltd.) and Loedige mixer (manufactured by Matsubo Co., Ltd.).

Next, the mixed raw materials are melt-kneaded to disperse colorants, wax, etc. into the amorphous polyester resin. Examples of the melt-kneading device include batch-type kneaders such as pressure kneaders and Banbury mixers, and continuous-type kneaders. The melt-kneading equipment includes a TEM extruder (manufactured by Toshiba Machinery Co., Ltd.), a TEX twin-screw kneader (manufactured by Japan Steel Works, Ltd.), a PCM kneader (manufactured by Ikegai Iron Works Co., Ltd.), a Kneedex (manufactured by Mitsui Mining Co., Ltd.), Examples include a KTK twin-screw extruder (manufactured by Kobe Steel, Ltd.), a twin-screw extruder (manufactured by K.C.K.), and a co-kneader (manufactured by Busu Corporation). A resin composition obtained by melt-kneading toner raw materials is rolled with two rolls or the like and cooled with water or the like.

Next, the cooled resin composition is pulverized to a desired particle size. In the pulverization process, after coarse pulverization is performed using crushers such as crushers, hammer mills, and feather mills, Kryptron System (manufactured by Kawasaki Heavy Industries), Super Rotor (manufactured by Nissin Engineering), Turbo Mill (manufactured by Turbo Industries), etc. Toner particles can be obtained by pulverizing with an air jet type pulverizer.

The toner particles are classified into toner particles having a desired particle size in a classification step. Examples of classifiers include Turboplex, Faculty, TSP, and TTSP separators (manufactured by Hosokawa Micron Corporation) using a centrifugal force classification method, and Elbow Jet (manufactured by Nittetsu Mining Co., Ltd.) using an inertial classification method.

It is preferable to disperse inorganic fine particles on the surface of the toner particles before surface treatment with hot air, and in this state, to fix the inorganic fine particles to the surface of the toner particles by surface treatment with hot air. As a method for dispersing inorganic fine particles on the surface of toner particles, a kneading machine such as a Henschel mixer can be used.

A surface treatment apparatus using hot air will be explained using FIG. 1. In the apparatus shown in FIG. 1, a mixture of toner particles and inorganic fine particles supplied quantitatively by a raw material quantitative supply means 1 is supplied to an inlet installed on a vertical line of the raw material supply means by compressed gas adjusted by a compressed gas adjustment means 2. It is led to tube 3. The mixture that has passed through the introduction pipe is uniformly dispersed by a conical protruding member 4 provided at the center of the raw material supply means, and is led to a radially extending supply pipe 5 extending in eight directions to a processing chamber 6 where heat treatment is performed. guided by. The flow of the mixture supplied to the processing chamber is regulated by a regulating means 9 provided within the processing chamber for regulating the flow of the mixture. The mixture supplied to the processing chamber is heat-treated while swirling within the processing chamber, and then cooled. Hot air for heat-treating the supplied mixture is supplied from the hot air supply means 7, distributed by the distribution member 12, and introduced into the processing chamber by swirling the hot air in a spiral manner by the swirling member 13 for swirling the hot air. be done. The rotating member 13 for rotating the hot air has a plurality of blades, and the rotation of the hot air can be controlled by changing the number and angle of the blades. The temperature of the hot air supplied into the processing chamber at the outlet of the hot air supply means 7 is preferably 100°C or more and 300°C or less, more preferably 130°C or more and 170°C or less. When the temperature at the outlet 11 of the hot air supply means is within the above range, fusion and coalescence of the toner particles is suppressed, and it becomes easier to uniformly surface-treat the toner particles.

The heat-treated toner particles whose surfaces have been heat-treated are cooled by cold air supplied from the cold air supply means 8. The temperature supplied from the cold air supply means 8 is preferably -20°C or more and 30°C or less. If the temperature of the cold air is within the above range, the heat-treated toner particles can be efficiently cooled, and the fusion and coalescence of the heat-treated toner particles can be suppressed without interfering with uniform surface treatment of the mixture. be able to. The absolute moisture content of the cold air is preferably 0.5 g/m ³ or more and 15.0 g/m ³ or less.

The cooled heat-treated toner particles are then collected by a collection means 10 at the lower end of the processing chamber. A blower (not shown) is provided at the tip of the collecting means, and the material is sucked and transported by the blower (not shown). The particle supply port 14 is provided so that the swirling direction of the supplied mixture and the swirling direction of the hot air are the same, and the recovery means 10 of the surface treatment apparatus maintains the swirling direction of the swirled particles. It is provided at the outer periphery of the processing chamber. The cold air supplied from the cold air supply means 8 is configured to be supplied horizontally and tangentially from the outer periphery of the apparatus to the inner periphery of the processing chamber. The swirling direction of the toner particles supplied from the particle supply port, the swirling direction of the cold air supplied from the cold air supply means, and the swirling direction of the hot air supplied from the hot air supply means are all the same direction. Therefore, turbulence does not occur in the processing chamber, the swirling flow inside the device is strengthened, a strong centrifugal force is applied to the toner particles, and the dispersibility of the toner particles is improved, so coalescence of the toner particles is suppressed and the shape It is possible to obtain toner particles with uniform properties.

A sieving step may be performed to remove coarse aggregates of additives and coarse particles formed during the heat treatment step. Examples of sieving devices include sieving machines such as Ultrasonic (manufactured by Koei Sangyo Co., Ltd.), Resona Sieve, Gyro Shifter (Tokuju Kogyo Co., Ltd.), Turbo Screener (manufactured by Turbo Kogyo Co., Ltd.), Hi-Bolter (manufactured by Toyo Hitech Co., Ltd.), and the above-mentioned sieving devices. Examples include the classifier mentioned in the classification process.

The toner may be used as a one-component developer, or may be mixed with a magnetic carrier and used as a two-component developer.

[Electrophotographic device]
The outline of the electrophotographic apparatus will be explained using FIG. 2. The electrophotographic apparatus shown in FIG. 2 includes four image forming units (first, second, third, and fourth image forming units) 21Y provided corresponding to four colors: yellow, magenta, cyan, and black; It is an electrophotographic full-color printer with 21M, 21C, and 21Bk.

The electrophotographic apparatus can form a four-color full-color image on a transfer material P (recording paper, plastic film, cloth, etc.) according to image signals from the following devices connected to the main body of the electrophotographic apparatus. Examples of such devices include a document reading device (not shown), a host device such as a personal computer, and an external device such as a digital camera.

The electrophotographic apparatus includes cylindrical electrophotographic photoreceptors 22Y, 22M, 22C, and 22Bk as image carriers in first to fourth image forming sections 21Y, 21M, 21C, and 21Bk. The toner images formed on the surfaces of these electrophotographic photoreceptors are transferred onto the surface of an intermediate transfer belt 28 serving as an intermediate transfer member. Then, the toner image on the surface of the intermediate transfer belt 28 is transferred onto the transfer material P.

Note that the electrophotographic apparatus may be a single-color device configured with only one image forming section, or may be an apparatus having image forming sections for two or more colors, preferably four or more colors. Further, an apparatus may be used in which one image forming section includes developing sections for a plurality of colors.

A plurality of components included in the image forming section may be integrated into a unit to form a process cartridge. By using a process cartridge, it can be configured to be detachable from the main body of an electrophotographic apparatus such as a copying machine or a laser beam printer.

The configuration and operation of the electrophotographic apparatus will be described in more detail. In the following description, elements commonly provided in each of the four image forming units 21Y, 21M, 21C, and 21Bk are given the same reference numerals with subscripts Y, M, C, and Bk. If there is no need to specifically explain them separately, the suffixes Y, M, C, and Bk added to the symbols to indicate that they are elements provided for one of the colors are omitted, and the suffixes Y, M, C, and Bk are omitted. Explain.

The image forming section 21 is provided with a cylindrical electrophotographic photoreceptor 22 as an image carrier. The electrophotographic photoreceptor 22 is rotationally driven in the direction of the arrow in the figure. Arranged around the electrophotographic photoreceptor 22 are a charging roller 23 as a charging means, a developing device 24 as a developing means, a primary transfer roller 25 as a primary transfer means, and a cleaning device 26 as a cleaning means. The cleaning device 26 has a cleaning blade. An image exposure device 7 serving as image exposure means is arranged above the electrophotographic photoreceptor 22 in the drawing. Further, an intermediate transfer belt 28 serving as an intermediate transfer body is arranged opposite to the electrophotographic photoreceptor 22 of each image forming section 21. The intermediate transfer belt 28 is wound around a drive roller 29, a secondary transfer opposing roller 30, and a driven roller 31, and is rotated in the direction of the arrow in the figure by the driving force transmitted to the drive roller 29. Intermediate transfer belt 28 contacts electrophotographic photoreceptor 22 at a position where primary transfer roller 25 and electrophotographic photoreceptor 2 face each other, forming a primary transfer portion (primary transfer nip). Further, a secondary transfer roller 32 as a secondary transfer means is provided at a position facing the secondary transfer opposing roller 30 with the intermediate transfer belt 28 interposed therebetween. The secondary transfer roller 32 contacts the intermediate transfer belt 28 at a position facing the secondary transfer opposing roller 30 to form a secondary transfer portion (secondary transfer nip).

The electrophotographic apparatus has a full-color image forming mode using all of the first to fourth image forming sections 21Y, 21M, 21C, and 21Bk, and a black monochrome image forming mode using only the fourth image forming section 21Bk. be able to. First, the image forming operation in full color image forming mode will be explained.

<Charging>
When the image forming operation starts, the surfaces of the electrophotographic photoreceptors 22Y, 22M, 22C, and 22Bk rotating in each image forming section 21Y, 21M, 21C, and 21Bk are uniformly charged by charging rollers 23Y, 23M, 23C, and 23Bk. Ru. At this time, a charging bias is applied to the charging rollers 23Y, 23M, 23C, and 23Bk from a charging bias power source. Note that the charging means may be corona charging.

As the charging means, either a non-contact charging method or a contact charging method can be used. The corona charging method, which is a non-contact charging method, has a relatively large output and is suitable for high-speed processes. The contact charging method is widely used because it has excellent charging uniformity and is small in size.

In the contact charging method, a charging roller is used as a charging member, which includes a conductive elastic layer provided on the outer periphery of a conductive support (core metal), and a resistance layer coated on the outer periphery of the conductive elastic layer. Then, this charging roller is rotatably arranged in contact with the surface of the electrophotographic photoreceptor, and a voltage is applied to the core metal to cause a minute electrical discharge near the contact nip between the charging roller and the electrophotographic photoreceptor. This is a method of charging the surface of an electrophotographic photoreceptor. The contact charging method includes a DC charging method in which only a DC voltage is applied to the core metal, and an AC+DC charging method in which an AC voltage is superimposed on the DC voltage to create an oscillating voltage. Furthermore, the charging member does not necessarily need to be in contact with the surface of the electrophotographic photoreceptor. As long as a dischargeable region determined by the gap voltage and the corrected Paschen curve is secured between the charging member and the electrophotographic photoreceptor, the charging member and the electrophotographic photoreceptor may be disposed close to each other in a non-contact manner with a gap of, for example, several tens of μm. Although this proximity charging is non-contact, it is functionally classified as contact charging.

The charging roller used for contact charging becomes contaminated with toner components when image formation is repeated, and its performance may change. A cleaning member may be provided to suppress this. As the cleaning member, for example, a cleaning roller having a foamed sponge or a brush provided on the outer periphery of a roller-shaped core metal is used, and the toner component is removed while the cleaning roller is brought into contact with the surface of the charging roller and rotated.

The electrophotographic photoreceptor 22 and the charging device (the charging roller 3 and the cleaning member excluding the charging bias power source) can be integrated into a unit as a process cartridge and configured to be detachable from the electrophotographic apparatus. Thereby, it can be easily replaced when the electrophotographic photoreceptor 22 reaches the end of its life, or when a prescribed number of images have been formed.

<Image exposure>
Next, image exposure is emitted from the image exposure devices 27Y, 27M, 27C, and 27Bk in accordance with image signals of separated colors corresponding to the respective image forming sections. As a result, each electrophotographic photoreceptor 22Y, 22M, 22C, and 22Bk is exposed according to the image information of the corresponding separated color, and an electrostatic image (latent image) is formed thereon according to the image signal. .

In image exposure, information read by a document reading device or electronic data generated by an information device such as a personal computer is converted into a signal, and the image is irradiated from the image exposure device 7 in accordance with this signal. As the image exposure means, scanning light of a laser beam, light irradiated by driving an LED array or a liquid crystal shutter array can be used.

For example, a laser beam scanner composed of a semiconductor laser, a polygon mirror, an fθ lens, etc. can be used. A laser beam scanner scans and exposes the surface of an electrophotographic photoreceptor with laser light that is modulated in accordance with an image signal input from a host processor such as an image reading device. The laser beam scanner can accommodate image signals subjected to digital image processing, such as pseudo-intermediate superprocessing. The amount of light for image exposure can be arbitrarily selected depending on the type of semiconductor laser, applied bias, mirror reflectance, and image signal, and can be designed depending on the electrophotographic photoreceptor used. The wavelength of image exposure can be selected depending on the type of semiconductor laser, and is selected depending on the electrophotographic photoreceptor used.

<developing>
The electrostatic images formed on the respective electrophotographic photoreceptors 22Y, 22M, 22C, and 22Bk are developed as toner images by toner contained in the respective developing devices 24Y, 24M, 24C, and 24Bk. For example, when a reversal development method is employed, toner from the developing device 24 adheres to exposed areas (bright area potential areas) on the electrophotographic photoreceptor 22.

The developing device includes a developer container, a developer stirring and conveying member, a developer carrier, and a developer layer thickness regulating member. As the developer, either magnetic or non-magnetic, one-component or two-component developer can be used. Two-component development is preferred because it provides stable images over a long period of time.

Magnetic carriers include iron powder with an oxidized surface, unoxidized iron powder, metal particles such as iron, lithium, calcium, magnesium, nickel, copper, zinc, cobalt, manganese, and rare earths, their alloy particles, and oxide particles. , a magnetic material such as ferrite, a magnetic material-dispersed resin carrier in which a magnetic material is dispersed in a binder resin, etc. can be used.

As the magnetic core particles (carrier core particles), known magnetic particles such as magnetite particles, ferrite particles, magnetic material-dispersed resin particles, and resin-filled porous magnetic particles can be used. Among these, magnetic material-dispersed resin particles are preferable from the viewpoint of extending the service life, since they can reduce the specific gravity of the magnetic carrier.

By lowering the specific gravity of the magnetic carrier, the load on the toner in the developing device is reduced, and it is possible to prevent toner components from adhering to the surface of the magnetic carrier. Furthermore, since the load between the carriers is reduced, peeling, chipping, and scraping of the coating resin layer can be suppressed. Furthermore, dot reproducibility can be improved, and high-definition images can be obtained.

As a specific method for manufacturing the magnetic material-dispersed resin particles, the following method may be mentioned. For example, submicron magnetic substances such as iron powder, magnetite particles, and ferrite particles are kneaded to be dispersed in a thermoplastic resin, pulverized to the desired carrier particle size, and thermally or mechanically shaped into spherical particles as necessary. It can be obtained by subjecting it to a chemical treatment. It is also possible to manufacture the magnetic material by dispersing the magnetic material in a monomer and polymerizing the monomer to form a resin.

Examples of the resin in this case include resins such as vinyl resin, polyester, epoxy resin, phenol resin, urea resin, polyurethane, polyimide, cellulose resin, silicone resin, acrylic resin, and polyether. The resin may be one type or a mixture of two or more types. In particular, phenol resin is preferred in that it increases the strength of the magnetic core particles. The true density and specific resistance can be adjusted by adjusting the amount of magnetic material. Specifically, in the case of magnetic particles, it is preferable to add 70 to 95% by mass based on the mass of the magnetic carrier.

The magnetic core particles must have a 50% particle diameter (D50) based on volume distribution of 20 μm or more and 80 μm or less to uniformly coat the coating resin, prevent carrier adhesion, and improve the density of the developer magnetic brush to obtain high-quality images. It is preferable to moderate the

The specific resistance of the magnetic core particles is such that good developability can be obtained when the specific resistance value at an electric field strength of 1000 (V/cm) is 1.0 x 10 ⁵ or more and 1.0 x 10 ¹⁴ Ωcm or less. Therefore, it is preferable.

Methods for coating the surface of the magnetic core particles with the coating resin composition include, but are not particularly limited to, coating methods such as dipping, spraying, brushing, dry coating, and fluidized bed coating. Among these, in order to take advantage of the unevenness that is a characteristic of the surface of porous magnetic core particles, the dipping method is more preferable from the viewpoint of improving developability, since it allows the ratio of thin and thick parts of the coating layer to be controlled. The reason why the developability is improved is considered as follows. This is because the uneven shape of the magnetic core particles allows the coating resin composition layer to have both a thin film portion and a thick film portion, so that the locally existing thin film portion acts as a charge relaxation effect.

The same method as in the filling step is used to prepare the coating resin composition solution for coating. Methods for suppressing granulation during the coating process include adjusting the resin concentration in the coating resin composition solution, the temperature inside the coating equipment, the temperature and degree of vacuum when removing the solvent, and the number of resin coating processes. It will be done.

The resin of the coating resin composition used for the coating layer is not particularly limited, but a vinyl resin that is a copolymer of a vinyl monomer having a cyclic hydrocarbon group in its molecular structure and another vinyl monomer is preferred. . By coating the vinyl resin, it is possible to suppress a decrease in the amount of charge under a high temperature and high humidity environment.

The reason why coating with the vinyl resin suppresses a decrease in the amount of charge under a high temperature and high humidity environment is considered as follows. When coating the surfaces of the filled core particles with the vinyl resin, a coating step is performed in which the vinyl resin dissolved in an organic solvent is mixed with the filled core particles and the solvent is removed. In this process, the solvent is removed while the cyclic hydrocarbon groups are oriented on the surface of the coating resin layer, and the highly hydrophobic cyclic hydrocarbon groups are oriented on the surface of the completed magnetic carrier. This is because a coating resin layer is formed.

Specific examples of the cyclic hydrocarbon group include cyclic hydrocarbon groups having 3 to 10 carbon atoms, such as cyclohexyl group, cyclopentyl group, adamantyl group, cyclopropyl group, cyclobutyl group, cycloheptyl group, and cyclooctyl group. , cyclononyl group, cyclodecyl group, isobonyl group, norbornyl group, boronyl group, etc. Among these, cyclohexyl group, cyclopentyl group, and adamantyl group are preferred, and cyclohexyl group is particularly preferred from the viewpoint of structural stability and high adhesion to the filled core particles.

Further, in order to adjust the glass transition temperature (Tg), other monomers may be further included as constituent components of the vinyl resin.

As other monomers used as constituent components of the vinyl resin, known monomers can be used, and examples include the following monomers. Examples include styrene, ethylene, propylene, butylene, butadiene, vinyl chloride, vinylidene chloride, vinyl acetate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, vinyl methyl ether, vinyl ethyl ether, and vinyl methyl ketone.

Further, the coating resin composition may contain conductive particles or charge controllable particles or materials. Examples of conductive particles include carbon black, magnetite, graphite, zinc oxide, and tin oxide. Among these, suitably using the filler effect of carbon black allows the surface tension of the coating resin composition to work suitably, which is preferable from the viewpoint of improving the coatability of the coating resin composition.

The reason why the coating properties of the coating resin composition can be improved by suitably using the filler effect of carbon black is derived from the primary particle size and cohesiveness of carbon black. That is, carbon black exhibits a large specific surface area due to its small primary particle diameter. On the other hand, carbon black has a high cohesive property, so it exists as large particles as aggregated particles. Depending on the primary particle size and aggregation property, the particles can significantly deviate from the relationship between particle size and specific surface area. That is, this is because the particle size is such that the surface tension of the coating resin composition acts, and the contact point is large due to the size of the specific surface area, so the surface tension of the coating resin composition acts easily.

The amount of conductive particles added is preferably 0.1 parts by mass or more and 10.0 parts by mass or less, based on 100 parts by mass of the coating resin, in order to adjust the resistance of the magnetic carrier. Examples of particles having charge control properties include particles of organometallic complexes, particles of organometallic salts, particles of chelate compounds, particles of monoazo metal complexes, particles of acetylacetone metal complexes, particles of hydroxycarboxylic acid metal complexes, and particles of polycarboxylic acid metals. Complex particles, polyol metal complex particles, polymethyl methacrylate resin particles, polystyrene resin particles, melamine resin particles, phenolic resin particles, nylon resin particles, silica particles, titanium oxide particles, alumina particles, etc. Can be mentioned. In order to adjust the amount of triboelectric charge, it is preferable that the amount of the particles having charge controllability added be 0.5 parts by mass or more and 50.0 parts by mass or less, based on 100 parts by mass of the coating resin.

The toner concentration in the two-component developer is preferably 2% by mass or more and 15% by mass or less, more preferably 4% by mass or more and 13% by mass or less.

<Primary transfer>
The toner images formed on the electrophotographic photoreceptors 22Y, 22M, 22C, and 22Bk are sequentially transferred onto the intermediate transfer belt 28 at each primary transfer portion (primary transfer nip) so that they overlap on the intermediate transfer belt 28. Transferred (primary transfer). At this time, a primary transfer bias having a polarity opposite to the normal charging polarity of the toner is applied to the primary transfer rollers 25Y, 25M, 25C, and 25Bk from a primary transfer bias power source. In this way, a multiple toner image in which toner images of four colors are superimposed is formed on the intermediate transfer belt 28.

The primary transfer means is composed of the primary transfer roller 25 and intermediate transfer belt 28 shown in FIG. The primary transfer roller 25 is composed of a metal core and a conductive layer formed in a cylindrical shape on the outer peripheral surface of the metal core. Both ends of the primary transfer roller 25 are urged toward the electrophotographic photoreceptor 2 by pressing members (not shown) such as springs. Thereby, the conductive layer of the primary transfer roller 5 is pressed against the surface of the electrophotographic photoreceptor 22 via the intermediate transfer belt 28 with a predetermined pressing force. Further, a primary transfer bias power source (not shown) as primary transfer bias output means is connected to the core bar. A primary transfer portion is formed between the electrophotographic photoreceptor 2 and the primary transfer roller 25 . An intermediate transfer belt 28 is sandwiched between the primary transfer section. The primary transfer roller 25 contacts the inner peripheral surface of the intermediate transfer belt 28 and rotates as the intermediate transfer belt 28 moves. During image formation, a primary transfer bias voltage is applied to the primary transfer roller 25 by a primary transfer bias power source, which has a polarity opposite to the normal charging polarity of the toner (in one example, negative polarity) (in one example, positive polarity). . Then, an electric field is formed between the primary transfer roller 5 and the electrophotographic photoreceptor 22 in a direction that moves the toner of the first polarity from the electrophotographic photoreceptor 2 toward the intermediate transfer belt 28 . As a result, the toner image on the electrophotographic photoreceptor 22 is transferred (primary transfer) to the surface of the intermediate transfer belt 28.

The primary transfer roller 25 may be a sponge roller or a metal roller. The sponge roller is designed with an appropriate electrical resistance value in order to appropriately apply the bias to the toner. When using a metal roller, instead of designing the electrical resistance value of the sponge, the position of the roller may be shifted from the position facing the drum (the position shown in FIG. 2).

The intermediate transfer belt 28 as an intermediate transfer member includes at least a base layer (substrate), and may be a laminate including a plurality of layers, including a surface layer (surface layer). The base layer is a semiconductive film made of resin containing a conductive filler.

The resin material for the base layer of an intermediate transfer belt composed of a single layer or an intermediate transfer belt composed of multiple layers includes crystals such as polyphenylene sulfide (PPS), polyetherimide (PEI), and polyether ether ketone (PEEK). Examples include thermoplastic resins. In particular, polyether ether ketone (PEEK) is suitable for the intermediate transfer belt because it is required to not elongate even under long-term tension load and to not wear its surface against rubbing by a cleaning blade. Furthermore, two or more of these resins may be selected and mixed as necessary.

At least one type of conductive filler such as carbon black or metal fine particles is blended into the resin material for the purpose of imparting conductivity to the base layer. Among these, carbon black is preferred from the viewpoint of mechanical properties. Carbon black has various names depending on its manufacturing method and raw materials. Specifically, these include Ketjen black, furnace black, acetylene black, thermal black, and gas black.

<cleaning>
Toner remaining on the surfaces of the electrophotographic photoreceptors 22Y, 22M, 22C, and 22Bk after the primary transfer (primary transfer residual toner) is collected by cleaning devices 26Y, 26M, 26C, and 26Bk. Separately, electric cleaning may be performed by performing a static elimination process using pre-exposure light from a pre-exposure means (not shown).

<Secondary transfer>
On the other hand, in accordance with the movement and timing of the toner image on the intermediate transfer belt 28, the transfer material P accommodated in a transfer material storage cassette (not shown) is moved to a secondary transfer portion (secondary transfer nip) by a supply roller 33 or the like. ). Then, the multiple toner images on the intermediate transfer belt 28 are collectively transferred (secondary transfer) onto the transfer material P at a secondary transfer portion (secondary transfer nip). At this time, a secondary transfer bias having a polarity opposite to the normal charging polarity of the toner is applied to the secondary transfer roller 32 from the secondary transfer bias power source. Note that toner remaining on the intermediate transfer belt 28 without being transferred to the transfer material P in the secondary transfer portion (secondary transfer nip) (secondary transfer residual toner) is collected by the intermediate transfer belt cleaner 35.

<Station>
The transfer material P onto which the toner image has been transferred is conveyed by a conveying member or the like to a fixing device 34 as a fixing means. By being heated and pressurized by the fixing device 34, the toners on the transfer material P are melted, mixed, and fixed to the transfer material P, forming a full-color permanent image. Thereafter, the transfer material P is discharged outside the machine.

[Process cartridge]
The process cartridge according to the present invention is a process cartridge that can be attached to and detached from the main body of an electrophotographic apparatus. It has the above-mentioned electrophotographic photoreceptor, a charging means, a developing means having toner, and a cleaning means having a cleaning blade.

[Toner manufacturing example]
(Manufacturing example 1)
An example of producing a toner using amorphous polyester resin L, amorphous polyester resin H, and crystalline polyester resin C will be shown below.

<Amorphous polyester resin L>
The following materials were weighed and put into a reaction tank equipped with a cooling tube, a stirrer, a nitrogen introduction tube, and a thermocouple.
・Polyoxypropylene (2.2)-2,2-bis(4-hydroxyphenyl)propane: 72.0 parts by mass (0.20 mol, 100.0 mol% based on the total number of moles of polyhydric alcohol)
- Terephthalic acid: 28.0 parts by mass (0.17 mol, 100.0 mol% based on the total number of moles of polycarboxylic acids)
- Tin 2-ethylhexanoate (esterification catalyst): 0.5 parts by mass Next, after purging the inside of the flask with nitrogen gas, the temperature was gradually raised while stirring, and for 4 hours while stirring at a temperature of 200 ° C. Made it react. Furthermore, the pressure inside the reaction tank was lowered to 8.3 kPa and maintained for 1 hour, then cooled to 180° C. and returned to atmospheric pressure.
- Trimellitic anhydride: 3 parts by mass (0.01 mol, 4.0 mol% based on the total number of moles of polycarboxylic acids)
- tert-butylcatechol (polymerization inhibitor): 0.1 part by mass After that, the above materials were added, the pressure inside the reaction tank was lowered to 8.3 kPa, and the reaction was allowed to proceed for 1 hour while maintaining the temperature at 180°C. After confirming that the softening point measured according to ASTM D36-86 reached 90°C, the temperature was lowered to stop the reaction, and amorphous polyester resin L was obtained.

<Amorphous polyester resin H>
The following materials were weighed and put into a reaction tank equipped with a cooling tube, a stirrer, a nitrogen introduction tube, and a thermocouple.
・Polyoxypropylene (2.2)-2,2-bis(4-hydroxyphenyl)propane: 72.3 parts by mass (0.20 mol, 100.0 mol% based on the total number of moles of polyhydric alcohol)
・Terephthalic acid: 18.3 parts by mass (0.11 mol, 65.0 mol% based on the total number of moles of polycarboxylic acids)
・Fumaric acid: 2.9 parts by mass (0.03 mol, 15.0 mol% based on the total number of moles of polycarboxylic acids)
- Tin 2-ethylhexanoate (esterification catalyst): 0.5 parts by mass Next, after purging the inside of the flask with nitrogen gas, the temperature was gradually raised while stirring, and while stirring at a temperature of 200 ° C. Allowed time to react. Furthermore, the pressure inside the reaction tank was lowered to 8.3 kPa and maintained for 1 hour, then cooled to 180°C and returned to atmospheric pressure.
- Trimellitic anhydride: 6.5 parts by mass (0.03 mol, 20.0 mol% based on the total number of moles of polycarboxylic acids)
- tert-butylcatechol (polymerization inhibitor): 0.1 part by mass After that, the above materials were added, the pressure inside the reaction tank was lowered to 8.3 kPa, and the reaction was allowed to proceed for 15 hours while maintaining the temperature at 160°C. After confirming that the softening point measured according to ASTM D36-86 reached 137°C, the temperature was lowered to stop the reaction, and amorphous polyester resin H was obtained.

<Crystalline polyester resin C>
The following materials were weighed and put into a reaction tank equipped with a cooling tube, a stirrer, a nitrogen introduction tube, and a thermocouple.
・1,6-hexanediol: 34.5 parts by mass (0.29 mol, 100.0 mol% based on the total number of moles of polyhydric alcohol)
- Dodecanedioic acid: 65.5 parts by mass (0.28 mol, 100.0 mol% based on the total number of moles of polycarboxylic acids)
- Tin 2-ethylhexanoate: 0.5 parts by mass After purging the inside of the flask with nitrogen gas, the temperature was gradually raised while stirring, and the mixture was reacted at a temperature of 140° C. for 3 hours while stirring. Next, the above materials were added, the pressure inside the reaction tank was lowered to 8.3 kPa, and the reaction was carried out for 4 hours while maintaining the temperature at 200°C.

Furthermore, after gradually releasing the pressure in the reaction tank and returning it to normal pressure, one or more aliphatic compounds selected from the group shown in Table 2 were added in an amount of 7.0 mol per 100.0 mol% of the raw material monomer. % and reacted at 200° C. for 2 hours under normal pressure. Thereafter, the pressure inside the reaction tank was reduced to 5 kPa or lower again, and the reaction was carried out at 200° C. for 3 hours to obtain a crystalline polyester resin C. The SP value (SP1) of crystalline polyester resin C was 11.3.

<Manufacture of toner particles>
The following materials were mixed using a Henschel mixer (Model FM-75, manufactured by Mitsui Mining Co., Ltd.) at a rotation speed of 20 s-1 and a rotation time of 5 minutes. (manufactured by). The barrel temperature during kneading was set so that the outlet temperature of the kneaded product was 115°C. The outlet temperature of the kneaded material was directly measured using a handy type thermometer (HA-200E) manufactured by Anritsu Keiki Co., Ltd.
・Amorphous polyester resin L 50 parts by mass ・Amorphous polyester resin H 50 parts by mass ・Crystalline polyester resin C 5 parts by mass ・Wax dispersant 5 parts by mass ・Fischer-Tropsch wax (hydrocarbon wax, peak of maximum endothermic peak) Temperature: 90°C) 5 parts by mass・C. I. Pigment Blue 15:3 7 parts by mass 3,5-di-t-butylsalicylic acid aluminum compound (Bontron E88 manufactured by Orient Chemical Industry Co., Ltd.) 0.3 parts by mass The obtained kneaded product was cooled and milled in a hammer mill to a thickness of 1 mm or less. The mixture was coarsely ground to obtain a coarsely ground product. The obtained coarse material was pulverized using a mechanical pulverizer (T-250, manufactured by Turbo Kogyo Co., Ltd.). Furthermore, classification was performed using Faculty F-300 (manufactured by Hosokawa Micron Corporation) to obtain toner particles 1. The operating conditions were a classification rotor rotation speed of 130 s ⁻¹ and a dispersion rotor rotation speed of 120 s ⁻¹ .

100 parts by mass of the obtained toner particles were surface-treated with 3.0 parts by mass of hydrophobic silica fine particles (BET: 25 m ² /g) surface-treated with 4% by mass of hexamethyldisilazane and 16 parts by mass of isobutyltrimethoxysilane. 0.2 parts by mass of titanium oxide fine particles (BET: 180 m ² /g) were added and mixed with a Henschel mixer (FM-75 type, manufactured by Mitsui Mining Co., Ltd.) at a rotation speed of 30 s-1 and a rotation time of 10 minutes. did. Then, heat treatment was performed using the surface treatment apparatus shown in FIG. The operating conditions were feed rate = 5 kg/hour, hot air temperature = 150°C, hot air flow rate = 6 m ³ /min, cold air temperature = -5°C, cold air flow rate = 4 m ³ /min, blower air volume = 20 m ³ /min, The injection air flow rate was 1 m ³ /min.

To 100 parts by mass of the heat-treated particles of the obtained toner, 1.0 part by mass of hydrophobic silica (BET: 200 m ² /g) and 1 part of titanium oxide fine particles surface-treated with isobutyltrimethoxysilane (BET: 80 m ² /g) were added. The toner of Production Example 1 was produced by mixing 0 parts by mass with a Henschel mixer (model FM-75, manufactured by Mitsui Mining Co., Ltd.) at a rotation speed of 30 s ^-1 and a rotation time of 10 minutes.

(Manufacturing example 2)
A toner of Production Example 2 was produced in the same manner as Production Example 1 except that the surface treatment with hot air was not performed.

[Example of manufacturing magnetic carrier]
(Manufacturing example 1)
<Manufacture of magnetic particles A>
While blowing nitrogen gas at 20 L/min into a reaction tank having a gas blowing pipe, 26.7 L of a ferrous sulfate aqueous solution containing 1.5 mol/L of Fe ²⁺ and 3 sodium silicate containing 0.2 mol/L of Si ⁴⁺ were added. 1.0 L of No. aqueous solution was added to 22.3 L of 3.4 mol/L sodium hydroxide aqueous solution, and the temperature was raised to pH 6.8 and temperature to 90°C. Add another 1.2 L of 3.5 mol/L aqueous sodium hydroxide solution, adjust the pH to 8.5, continue stirring, change the gas to air, and aerate at 100 L/min for 90 minutes. The resulting particles were neutralized to pH 7 using dilute sulfuric acid, and the resulting particles were washed with water, filtered, dried, and pulverized to obtain magnetic particles A having a number average particle size of 0.30 μm.

The obtained magnetic particles A and a silane coupling agent (3-glycidoxypropylmethyldimethoxysilane) (1.2 parts by mass per 100 parts by mass of the magnetite fine particles) were introduced into a container. Then, the magnetic particles A were surface-treated by high-speed mixing and stirring at 100° C. for 1 hour in the container.

<Manufacture of magnetic particles B>
1.2 parts by mass of a silane coupling agent (3-(2-aminoethylamino)propyltrimethoxysilane) was mixed with magnetic particles A based on 100 parts by mass of spherical hematite particles with a number average particle size of 0.40 μm. The surface was treated in the same way.

<Manufacturing example of magnetic carrier core>
- 10.0 parts by mass of phenol - 15.0 parts by mass of formaldehyde solution (37% by mass aqueous solution of formaldehyde) - 90.0 parts by mass of surface-treated magnetic particles A - 10.0 parts by mass of surface-treated magnetic particles B - 25 parts by mass Mass % Aqueous ammonia 3.5 parts by mass/Water 15.0 parts by mass The above materials were introduced into a reaction vessel and mixed well at a temperature of 40°C. Thereafter, while stirring, the mixture was heated to 85°C at an average temperature increase rate of 1.5°C/min, maintained at 85°C, and cured by polymerization reaction for 3 hours. The peripheral speed of the stirring blade at this time was 1.96 m/sec.

After the polymerization reaction, the mixture was cooled to 30° C. and water was added. The precipitate obtained by removing the supernatant liquid was washed with water and further air-dried. The obtained air-dried material was dried at 180° C. for 5 hours under reduced pressure (5 mmHg or less) to obtain a magnetic carrier core (50% particle size (D50) based on volume distribution: 35.5 μm), which is a magnetic material-dispersed resin particle. I got it.

<Preparation of coating resin solution>
・50 parts by mass of a solution obtained by polymerizing cyclohexyl methacrylate monomer, methyl methacrylate macromonomer, and methyl methacrylate macromonomer ・46 parts by mass of toluene ・1.0 parts by mass of carbon black #25 (manufactured by Mitsubishi Chemical Corporation) ・Melamine-formaldehyde condensate Eposter S6 (manufactured by Nippon Shokubai Co., Ltd.) was dispersed in a paint shaker for 1 hour to prepare a resin solution.

<Example of manufacturing magnetic carrier>
The above-mentioned coating resin solution was added to 100 parts by mass of the magnetic carrier core in a planetary motion mixer (Nauta mixer VN model manufactured by Hosokawa Micron) maintained at a temperature of 60° C. under reduced pressure (1.5 kPa). , was added so that the solid content of the resin component was 2.0 parts by mass. As for the charging method, 1/3 of the resin solution was charged, and the solvent removal and coating operations were performed for 20 minutes. Next, 1/3 of the resin solution was added, and solvent removal and coating operations were performed for 20 minutes, and then 1/3 of the resin solution was added, and solvent removal and coating operations were performed for 20 minutes.

Thereafter, the magnetic carrier coated with the coating resin composition is transferred to a mixer (drum mixer UD-AT type manufactured by Sugiyama Heavy Industries, Ltd.) having a spiral blade in a rotatable mixing container. The mixture was heat-treated at a temperature of 120° C. for 2 hours in a nitrogen atmosphere while stirring the mixing container at 10 revolutions per minute. The magnetic carrier of Production Example 1 was produced by separating the obtained magnetic carrier 1 into low-magnetic products by magnetic separation, passing it through a sieve with an opening of 150 μm, and classifying it with an air classifier.

[Example of manufacturing electrophotographic photoreceptor]
(Manufacturing example 1)
An aluminum cylinder with a diameter of 30 mm and a length of 346 mm is used as a support, and a coating liquid consisting of the following materials is dip-coated onto the support in the order of a conductive layer, an undercoat layer, a charge generation layer, and a charge transport layer. A photographic photoreceptor was manufactured.

As a coating liquid for the conductive layer, 10 parts of tin oxide (SnO ₂ ) coated barium sulfate, 2 parts of titanium oxide, 6 parts of phenol resin, 0.001 part of silicone oil, 4 parts of methanol, and 16 parts of methoxypropanol were added to a glass plate with a diameter of 1 mm. A conductive layer coating solution was prepared by performing a dispersion treatment for 2 hours using a bead-containing sand mill device. A conductive layer coating solution was applied onto a support by dip coating to form a coating film, and the coating film was thermally cured at 140° C. for 30 minutes to form a conductive layer with a thickness of 15 μm.

Next, a coating solution for an undercoat layer was prepared by dissolving 5 parts of N-methoxymethylated nylon and 1 part of copolymerized nylon in a mixed solvent of 65 parts of methanol and 30 parts of n-butanol. The coating solution for undercoat layer was applied onto the conductive layer by dip coating to form an undercoat layer having a thickness of 0.6 μm.

Next, 20 parts of hydroxygallium phthalocyanine crystal (charge generating substance) of a crystal form having strong peaks at 7.4° and 28.2° of Bragg angle 2θ±0.2° in CuKα characteristic X-ray diffraction, and the following formula ( A) 0.2 part of a calixarene compound represented by

10 parts of polyvinyl butyral resin (trade name: S-LEC BX-1, manufactured by Sekisui Chemical Co., Ltd.) and 600 parts of cyclohexanone were placed in a sand mill using glass beads with a diameter of 1 mm, and dispersed for 4 hours. Thereafter, 600 parts of ethyl acetate was added to prepare a charge generation layer coating solution. A charge generation layer coating solution was applied onto the undercoat layer by dip coating to form a coating film, and the coating film was dried at 80° C. for 15 minutes to form a charge generation layer having a thickness of 0.19 μm.

Next, 10 parts of the compound represented by the above formula (8) (charge transport substance) and 70 parts of the compound represented by the following formula (10) (charge transport substance)

1 part of resin (C) shown in Table 3 as the siloxane moiety-containing resin, a structural unit represented by the above formula (1-4) and a structural unit represented by the above formula (3-5) ((1-4)/(3 -5)=2/8 (molar ratio)) was dissolved in 360 parts of o-xylene, 160 parts of methyl benzoate, and 270 parts of dimethoxymethane to prepare a charge transport layer. A coating solution was prepared. A charge transport layer coating solution was applied onto the charge generation layer by dip coating to form a coating film, and the coating film was dried at 120° C. for 60 minutes to form a charge transport layer having a thickness of 20 μm.

In this way, the electrophotographic photoreceptor of Production Example 1, which has a support, a conductive layer, an undercoat layer, a charge generation layer, and a charge transport layer in this order, and the charge transport layer is the surface layer of the electrophotographic photoreceptor, is produced. Manufactured.

(Manufacturing examples 2 to 8)
Electrophotographic photoreceptors of Production Examples 2 to 8 were produced in the same manner as Production Example 1, except that the binder resin, siloxane moiety-containing resin, and charge transport material in the charge transport layer were changed as shown in Table 3.

[Example 1]
As the electrophotographic device for evaluation, a modified copying machine (trade name: iRC3380) manufactured by Canon Inc. was used. As the electrophotographic photoreceptor, the electrophotographic photoreceptor of Production Example 1 was used. Further, a two-component developer was used as the developer, the toner of Production Example 1 was used as the toner of the two-component developer, and the magnetic carrier of Production Example 1 was used as the carrier. Toner and magnetic carrier were put into a V-type mixer (V-10 type: Tokuju Seisakusho Co., Ltd.) so that the toner concentration in the two-component developer was 9% by mass, and the rotation time was 5 minutes at 0.5 s ^-1 . A developer (two-component developer) was obtained by mixing under the following conditions.

Evaluation was performed by outputting 50,000 images (horizontal A4 paper, 5% print ratio, intermittent feeding of 2 sheets) under normal temperature and normal humidity (23° C./50% RH) environment. During paper passing, the same charging conditions, exposure conditions, development conditions, and transfer conditions as for the first paper were used.

Using an X-Rite color reflection densitometer (500 series, manufactured by X-Rite), the 50,000th halftone image was compared with the first halftone image and evaluated using the following evaluation criteria. Ta. The evaluation results are shown in Table 4.

(Image evaluation criteria)
A: Good, B: Image density slightly decreased, C: Image density decreased, D: Image density decreased and streak-like image defects occurred [Examples 2 to 6, Comparative Examples 1 and 2]
Evaluation was performed in the same manner as in Example 1, except that the electrophotographic photoreceptor and developer in Example 1 were changed as shown in Table 4. The evaluation results are shown in Table 4.

The disclosure of this embodiment includes the following configurations.
(Configuration 1)
electrophotographic photoreceptor,
Charging means for charging the surface of the electrophotographic photoreceptor;
image exposure means for irradiating the charged surface of the electrophotographic photoreceptor with image exposure light to form an electrostatic latent image on the surface of the electrophotographic photoreceptor;
a developing means having a toner and for developing the electrostatic latent image formed on the surface of the electrophotographic photoreceptor with the toner to form a toner image on the surface of the electrophotographic photoreceptor;
a transfer means for transferring the toner image formed on the surface of the electrophotographic photoreceptor to a transfer material; and
a cleaning means having a cleaning blade and for removing toner remaining on the surface of the electrophotographic photoreceptor by bringing the cleaning blade into contact with the surface of the electrophotographic photoreceptor;
An electrophotographic device having
The electrophotographic photoreceptor is
charge transport material,
at least one binder resin selected from the group consisting of a polycarbonate resin having a structural unit represented by the above formula (1) and a polyester resin having a structural unit represented by the above formula (2), and
A siloxane moiety-containing resin selected from the group consisting of a styrene-(meth)acrylate resin having a siloxane moiety, a polycarbonate resin having a siloxane moiety, and a polyester resin having a siloxane moiety;
has a surface layer containing
The toner has toner particles containing an amorphous polyester resin, a crystalline polyester resin, and inorganic fine particles,
The inorganic fine particles fixed by surface treatment with hot air are present on the surface of the toner particles.
An electrophotographic device characterized by:
(Configuration 2)
A polycarbonate resin having a structural unit represented by the above formula (1) has a structural unit represented by the above formula (1) and a structure represented by the above formula (3),
A polyester resin having a structural unit represented by the above formula (2) has a structural unit represented by the above formula (2) and a structural unit represented by the above formula (4),
The electrophotographic apparatus according to configuration 1.
(Configuration 3)
The electrophotographic device according to configuration 1 or 2, wherein the siloxane moiety-containing resin has a structure represented by the above formula (5) as the siloxane moiety.
(Configuration 4)
The electrophotographic device according to any one of configurations 1 to 3, wherein the siloxane moiety-containing resin has a structural unit represented by the above formula (6) as the siloxane moiety.
(Configuration 5)
Any of configurations 1 to 4, wherein the surface layer contains as the charge transport substance at least one compound selected from the group consisting of the compound represented by the above formula (7) and the compound represented by the above formula (8). The electrophotographic apparatus according to configuration (1).
(Configuration 6)
A process cartridge removably attachable to the main body of an electrophotographic apparatus,
The process cartridge is
electrophotographic photoreceptor,
Charging means for charging the surface of the electrophotographic photoreceptor;
a developing means having a toner and for developing an electrostatic latent image formed on the surface of the electrophotographic photoreceptor with the toner to form a toner image on the surface of the electrophotographic photoreceptor;
a cleaning means having a cleaning blade and for removing toner remaining on the surface of the electrophotographic photoreceptor by bringing the cleaning blade into contact with the surface of the electrophotographic photoreceptor;
has
The electrophotographic photoreceptor is
charge transport material,
at least one binder resin selected from the group consisting of a polycarbonate resin having a structural unit represented by the above formula (1) and a polyester resin having a structural unit represented by the above formula (2), and
A siloxane moiety-containing resin selected from the group consisting of a styrene-(meth)acrylate resin having a siloxane moiety, a polycarbonate resin having a siloxane moiety, and a polyester resin having a siloxane moiety;
has a surface layer containing
The toner has toner particles containing an amorphous polyester resin, a crystalline polyester resin, and inorganic fine particles,
The inorganic fine particles fixed by surface treatment with hot air are present on the surface of the toner particles.
A process cartridge characterized by:

1 Raw material quantitative supply means 2 Compressed air adjustment means 3 Introductory pipe 4 Protruding member 5 Supply pipe 6 Processing chamber 7 Hot air supply means 8 Cold air supply means 9 Regulation means 10 Recovery means 11 Hot air supply means outlet 12 Distribution member 13 Rotating member 14 Particles Supply port 21, 21Y, 21М, 21C, 21Bk Image forming section 22, 22Y, 22М, 22C, 22Bk Electrophotographic photoreceptor 23, 23Y, 23М, 23C, 23Bk Charging roller 24, 24Y, 24М, 24C, 24Bk Developing device 25 , 25Y, 25М, 25C, 25Bk Primary transfer roller 26, 26Y, 26М, 26C, 26Bk Cleaning device 27, 27Y, 27М, 27C, 27Bk Image exposure device 28 Intermediate transfer belt 29 Drive roller 30 Secondary transfer opposing roller 31 Driven roller 32 Secondary transfer roller 33 Supply roller 34 Fixing device 35 Intermediate transfer belt cleaner P Transfer material

Claims (6)

electrophotographic photoreceptor,
Charging means for charging the surface of the electrophotographic photoreceptor;
image exposure means for irradiating the charged surface of the electrophotographic photoreceptor with image exposure light to form an electrostatic latent image on the surface of the electrophotographic photoreceptor;
a developing means having a toner and for developing the electrostatic latent image formed on the surface of the electrophotographic photoreceptor with the toner to form a toner image on the surface of the electrophotographic photoreceptor;
a transfer means for transferring the toner image formed on the surface of the electrophotographic photoreceptor to a transfer material; and
a cleaning means having a cleaning blade and for removing toner remaining on the surface of the electrophotographic photoreceptor by bringing the cleaning blade into contact with the surface of the electrophotographic photoreceptor;
An electrophotographic device having
The electrophotographic photoreceptor is
charge transport material,
At least one binder resin selected from the group consisting of a polycarbonate resin having a structural unit represented by the following formula (1) and a polyester resin having a structural unit represented by the following formula (2), and
A siloxane moiety-containing resin selected from the group consisting of a styrene-(meth)acrylate resin having a siloxane moiety, a polycarbonate resin having a siloxane moiety, and a polyester resin having a siloxane moiety;
has a surface layer containing
The toner has toner particles containing an amorphous polyester resin, a crystalline polyester resin, and inorganic fine particles,
The inorganic fine particles fixed by surface treatment with hot air are present on the surface of the toner particles.
An electrophotographic device characterized by:

(In formula (1), R ¹ to R ⁴ each independently represent a hydrogen atom or a methyl group.)

(In formula (2), R ¹¹ to R ¹⁴ each independently represent a hydrogen atom or a methyl group. Y ¹ is a m-phenylene group, a p-phenylene group, or two p-phenylene groups. (Indicates a divalent group formed by bonding through an oxygen atom.) A polycarbonate resin having a structural unit represented by the formula (1) above has a structural unit represented by the formula (1) and a structure represented by the following formula (3),
A polyester resin having a structural unit represented by the formula (2) above has a structural unit represented by the formula (2) and a structural unit represented by the following formula (4),
An electrophotographic apparatus according to claim 1.

(In formula (3), R ⁵ to R ^{8 each} independently represent a hydrogen atom or a methyl group. Indicates a methylene group, a cyclohexylidene group, or an oxygen atom having a monovalent group as a substituent.)

(In formula (4), R ¹⁵ to R ¹⁸ each independently represent a hydrogen atom or a methyl ^group . ^Y2 represents a methylene group, a cyclohexylidene group, or an oxygen atom having a monovalent group as a substituent. (Indicates a divalent group bonded via a The electrophotographic apparatus according to claim 1 or 2, wherein the siloxane moiety-containing resin has a structure represented by the following formula (5) as the siloxane moiety.

(In formula (5), a and b each independently indicate the average value of the number of repeats of the structure in parentheses. a is 10 or more and 100 or less. b is 1 or more and 10 or less.) The electrophotographic apparatus according to claim 1 or 2, wherein the siloxane moiety-containing resin has a structural unit represented by the following formula (6) as the siloxane moiety.

(In formula (6), c, d, and e each independently indicate the average value of the number of repeats of the structure in parentheses. c and e each independently range from 1 to 10. d is (10 or more and 100 or less) 3. The surface layer according to claim 1 or 2, wherein the surface layer contains at least one compound selected from the group consisting of a compound represented by the following formula (7) and a compound represented by the following formula (8) as the charge transport substance. The electrophotographic device described.

A process cartridge removably attachable to the main body of an electrophotographic apparatus,
The process cartridge is
electrophotographic photoreceptor,
Charging means for charging the surface of the electrophotographic photoreceptor;
a developing means having a toner and for developing an electrostatic latent image formed on the surface of the electrophotographic photoreceptor with the toner to form a toner image on the surface of the electrophotographic photoreceptor;
a cleaning means having a cleaning blade and for removing toner remaining on the surface of the electrophotographic photoreceptor by bringing the cleaning blade into contact with the surface of the electrophotographic photoreceptor;
has
The electrophotographic photoreceptor is
charge transport material,
At least one binder resin selected from the group consisting of a polycarbonate resin having a structural unit represented by the following formula (1) and a polyester resin having a structural unit represented by the following formula (2), and
A siloxane moiety-containing resin selected from the group consisting of a styrene-(meth)acrylate resin having a siloxane moiety, a polycarbonate resin having a siloxane moiety, and a polyester resin having a siloxane moiety;
has a surface layer containing
The toner has toner particles containing an amorphous polyester resin, a crystalline polyester resin, and inorganic fine particles,
The inorganic fine particles fixed by surface treatment with hot air are present on the surface of the toner particles.
A process cartridge characterized by:

(In formula (1), R ¹ to R ⁴ each independently represent a hydrogen atom or a methyl group.)

(In formula (2), R ¹¹ to R ¹⁴ each independently represent a hydrogen atom or a methyl group. Y ¹ is a m-phenylene group, a p-phenylene group, or two p-phenylene groups. (Indicates a divalent group formed by bonding through an oxygen atom.)

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