JP2011123366A - Electrophotographic photoreceptor and electrophotographic apparatus using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor reducing a potential increase after exposure, image blurring and image deletion when images are repeatedly formed in high temperature and high humidity environment, and to provide an electrophotographic apparatus and an electrophotographic method using the electrophotographic photoreceptor. <P>SOLUTION: The electrophotographic photoreceptor has a protective layer 39 on the surface of a photosensitive layer 33 formed on a conductive support 31, wherein the protective layer contains fluorocarbon resin fine particles and a compound expressed by general formula (1), and the fluorocarbon resin fine particles are included in a proportion of 20% or more and 60% or less by a volume fraction in the protective layer. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an electrophotographic photosensitive member, and an electrophotographic apparatus and an electrophotographic method using the electrophotographic photosensitive member.

  In recent years, there has been a remarkable development in information processing systems using electrophotography. In particular, laser printers and digital copying machines that record information using light after converting information into digital signals have significantly improved print quality and reliability. Furthermore, they have been applied to laser printers or digital copiers capable of full-color printing by merging with high-speed technology. From such a background, it is particularly important to achieve both high image quality and high durability as functions of the electrophotographic photosensitive member.

In order to realize such a function of the electrophotographic photosensitive member, an organic photosensitive material is generally widely used for the photosensitive layer for reasons such as cost, productivity and safety.
However, electrophotographic photoreceptors using organic photosensitive materials are prone to film scraping due to repeated use, and as the photosensitive layer is scraped, the charging potential of the photoreceptor decreases and the photosensitivity deteriorates. There is a strong tendency to promote background contamination, image density reduction, or image quality degradation due to scratches on the surface. In addition to this, there has been a strong demand for higher durability of the electrophotographic photosensitive member due to circumstances such as a reduction in the diameter of the photosensitive member accompanying the recent increase in the speed of the electrophotographic apparatus or the reduction in the size of the apparatus.

  On the other hand, in recent years, with a demand for higher image quality in the market, a small-diameter and spherical toner has attracted attention. However, such a small-diameter and spherical toner makes it difficult to clean on the electrophotographic photosensitive member and easily causes poor cleaning, which causes image deterioration due to toner filming or fusion. There is.

  For the purpose of imparting surface releasability to such problems, the surface friction coefficient of the electrophotographic photosensitive member can be initially reduced by incorporating fluororesin fine particles as a lubricant in the surface layer of the electrophotographic photosensitive member. The technology to make it known is known. However, it is difficult to ensure sufficient surface releasability by repeated use even with such a technique.

  Therefore, in Patent Document 1, for example, a protective layer containing fluororesin fine particles as a solid lubricant is formed on the outermost surface layer of the photosensitive layer, and the protective layer has at least a volume fraction of 20% to 60% fluororesin fine particles, An electrophotographic photoreceptor containing an amine compound having a specific structure has been proposed. According to such a proposal, the resistance of the outermost surface is reduced by an oxidizing gas such as ozone or NOx adsorbed on the surface of the protective layer at the time of image formation, so that the durability is increased and the residual potential is increased or the charge is decreased. Therefore, it is possible to stably obtain a high-quality image even when used repeatedly for a long time. However, the ability to prevent image blur and image flow during repeated image formation under high temperature and high humidity is insufficient.

  Further, for example, in Patent Document 2, a protective layer containing fluororesin fine particles is formed on the outermost surface layer of the photosensitive layer, and the fluororesin fine particles and hexabenzoyloxy having a volume fraction of 20% to 60% at least in the protective layer. An electrophotographic photoreceptor containing phenylene has been proposed. According to such a proposal, high durability and high image quality can be realized. However, as in Patent Document 1, image blur and image flow during repeated image formation under high temperature and high humidity cannot be sufficiently prevented.

  Furthermore, in Patent Document 3, the charge transport layer contains a charge transport material, a binder resin, and a specific diamine compound as an antioxidant, and the content of the diamine compound with respect to the charge transport material is 0.5 to 10% by weight. A multilayer electrophotographic photosensitive member has been proposed in which the content of the binder resin with respect to 100 parts by weight of the charge transport material is 120 to 300 parts by weight. According to such a proposal, it is said that a laminated electrophotographic photosensitive member having high sensitivity and excellent wear resistance and little sensitivity deterioration with respect to long-term use can be realized, but a diamine compound is used for the charge transport layer. Since it is contained, the post-exposure potential increase during repeated use is relatively large, and the post-exposure potential increase amount is particularly large under high temperature and high humidity.

  The present invention has been made in view of the above-described problems in the prior art, and includes an electrophotographic photoreceptor that reduces post-exposure potential increase, image blurring, and image flow during repeated image formation under high temperature and high humidity, and the electrophotographic photosensitive member. An object is to provide an electrophotographic apparatus and an electrophotographic method using the electrophotographic photosensitive member.

  In order to solve the above problems, an electrophotographic photosensitive member according to the present invention, and an electrophotographic apparatus and an electrophotographic method using the electrophotographic photosensitive member are specifically described in the following technologies (A) to (I). Characteristic.

(A): an electrophotographic photosensitive member having a protective layer on the surface of a photosensitive layer formed on a conductive support, wherein the protective layer is represented by fluororesin fine particles and the following general formula (1) Wherein the fluororesin fine particles are contained in the protective layer in a volume fraction of 20% or more and 60% or less.

[In the general formula (1), A and B are groups selected from the following (i) and (ii), which may be the same or different.
(I) _-CH 2 X
_(Ii) -CH 2 _CH 2 Y
However, X and Y each represent an aromatic residue that may have a substituent, a cycloalkyl group that may have a substituent, or a heterocycloalkyl group that may have a substituent. ]

(B): The electrophotographic photosensitive member according to (A), wherein the compound represented by the general formula (1) is an amine compound represented by the following chemical formula (2).

(C): The electrophotographic photosensitive member according to (A), wherein the compound represented by the general formula (1) is an amine compound represented by the following chemical formula (3).

  With the configuration described in (A) to (C) above, it is possible to reduce image blur and image flow during repeated image formation under high temperature and high humidity.

(D): a charging step for charging the surface of the electrophotographic photosensitive member according to any one of (A) to (C), and an exposure step for forming an electrostatic latent image on the electrophotographic photosensitive member. An electrophotographic method comprising: a developing step of developing the electrostatic latent image to form a toner image; and a transferring step of transferring the toner image onto a recording material.

  With the configuration described in (D) above, it is possible to reduce image blur and image flow during repeated image formation under high temperature and high humidity.

(E): a fluororesin in which the fluororesin fine particles exposed on the surface of the electrophotographic photosensitive member are rubbed and deformed and extended by a fluororesin fine particle deformation / extension member provided in contact with the surface of the electrophotographic photoconductor The electrophotographic method according to (D) above, further comprising a fine particle deformation and extension step.

  With the configuration described in (E) above, image blur and image flow during repeated image formation under high temperature and high humidity are reduced, and toner image transferability is excellent and cleaning properties are good.

(F): The electrophotographic photosensitive member according to any one of (A) to (C) above, charging means for charging the electrophotographic photosensitive member, and an electrostatic latent image on the electrophotographic photosensitive member. Exposure means for forming, developing means for developing the electrostatic latent image to form a toner image, and transfer means for transferring the toner image onto a recording material. An electrophotographic apparatus comprising an LD or an LED for forming a latent image.

  With the configuration described in (F) above, it is possible to reduce image blur and image flow during repeated image formation under high temperature and high humidity.

(G): The developing unit forms one or more toner images, and the transfer unit includes a primary transfer unit, an intermediate transfer member, and a secondary transfer unit, and the primary transfer unit includes: The toner image developed on the electrophotographic photosensitive member is primarily transferred onto the intermediate transfer member, and the secondary transfer unit secondarily transfers the toner image on the intermediate transfer member onto a recording material, and the development. When the means forms two or more toner images, the primary transfer unit performs primary transfer so that the two or more toner images are stacked on the intermediate transfer member, and the secondary transfer unit includes the recording material. The electrophotographic apparatus according to (F), wherein two or more toner images laminated on the intermediate transfer member are secondarily transferred at once.

  With the configuration described in (G) above, it is possible to reduce image blur and image flow during repeated image formation under high temperature and high humidity, and further reduce color misregistration and density unevenness.

(H): a fluororesin fine particle deformation / extension member provided in contact with the electrophotographic photoreceptor, the fluororesin fine particle deformation / extension member sliding the fluororesin fine particles exposed on the surface of the electrophotographic photoreceptor. The electrophotographic apparatus according to (F) or (G), wherein the electrophotographic apparatus is deformed and stretched by rubbing.

  With the configuration described in (H) above, image blur and image flow during repeated image formation under high temperature and high humidity are reduced, and further, toner image transferability is excellent and cleaning properties are good.

(I): The electrophotographic photosensitive member according to any one of (A) to (C) above, one or more selected from a charging unit, an exposure unit, a developing unit, a cleaning unit, and a transfer unit, Is a process cartridge characterized in that it is configured integrally and is detachable from the main body of the electrophotographic apparatus.

  With the configuration described in (I) above, image blur and image flow during repeated image formation under high temperature and high humidity are reduced, and further, the electrophotographic apparatus can be reduced in size, and can be easily attached and removed as an electrophotographic unit. It can be.

  According to the present invention, an electrophotographic photosensitive member with reduced post-exposure potential increase, image blur and image flow during repeated image formation under high temperature and high humidity, and an electrophotographic apparatus and an electrophotographic device using the electrophotographic photosensitive member. A method can be provided.

1 is a schematic view showing an example of a layer configuration of an electrophotographic photoreceptor according to the present invention. It is the schematic which shows another example of the layer structure of the electrophotographic photoreceptor which concerns on this invention. It is the schematic which shows another example of the layer structure of the electrophotographic photoreceptor which concerns on this invention. 1 is a schematic diagram illustrating an example of a configuration of an electrophotographic apparatus according to the present invention. It is the schematic which shows another example of a structure of the electrophotographic apparatus which concerns on this invention. It is the schematic which shows an example of a structure of the process cartridge which concerns on this invention.

[Electrophotographic photoconductor]
The electrophotographic photosensitive member according to the present invention is an electrophotographic photosensitive member having a protective layer on the surface of a photosensitive layer formed on a conductive support, and the protective layer includes fluororesin fine particles and the following general formula ( 1), wherein the fluororesin fine particles are contained in the protective layer in a volume fraction of 20% or more and 60% or less.

[In the general formula (1), A and B are groups selected from the following (i) and (ii), which may be the same or different.
(I) _-CH 2 X
_(Ii) -CH 2 _CH 2 Y
However, X and Y each represent an aromatic residue that may have a substituent, a cycloalkyl group that may have a substituent, or a heterocycloalkyl group that may have a substituent. ]

Next, the electrophotographic photoreceptor according to the present invention will be described in more detail.
Although the embodiments described below are preferred embodiments of the present invention, various technically preferable limitations are attached thereto, but the scope of the present invention is intended to limit the present invention in the following description. Unless otherwise described, the present invention is not limited to these embodiments.

  In order to achieve high durability and a low surface friction coefficient of an electrophotographic photoreceptor (hereinafter also simply referred to as a photoreceptor), fluororesin fine particles are added to the outermost surface layer of the photoreceptor (that is, a protective layer described later in detail). Although it is known that the inclusion is effective, in order to stably maintain the low surface friction coefficient, fluororesin fine particles having a volume fraction of 20% or more are required in the outermost surface layer. Normally, when a layer having such a structure is formed, the interaction between the fluororesin fine particles is increased, making it difficult to finely disperse the fluororesin fine particles in the dispersion liquid. Secondary agglomerated particles (secondary particles) increase. If such secondary particles are too large in the coating film, the surface of the coating film becomes rough, resulting in poor cleaning and disorder of the toner image. In addition, the laser light is scattered on the aggregates, and the exposure latent image is disturbed and the potential contrast is insufficient to cause an abnormal image.

  On the other hand, when the particles are uniformly dispersed to the primary particles, the above-mentioned problems are solved, but on the other hand, the portion where the fluororesin fine particles are exposed on the surface of the coating is reduced, resulting in the toner and the fluororesin. The contact area with the fine particles is reduced, and the effect of reducing the surface friction coefficient of the photoreceptor becomes insufficient.

As a result of intensive studies, the present inventors need to localize the fluororesin fine particles within a certain range and cover a certain area of the coating film surface in consideration of toner cleaning properties. Found that there is.
That is, the fluororesin fine particles having a secondary particle size of 0.3 to 4 μm are most preferably in a state where the surface of the photoreceptor is covered by 12 to 33% by area ratio (covering area ratio). It has been found that in order to cover the surface of the photoreceptor by 12 to 33% in terms of the coverage area ratio, the protective layer of the photoreceptor needs to contain 20 to 60% fluororesin fine particles by volume fraction.

  However, in such a photoconductor having a high concentration of secondary particles of fluororesin fine particles in the outermost surface layer, the chargeability may be reduced depending on the use conditions, which may cause problems such as memory effect (afterimage). In addition, an oxidizing gas such as ozone or NOx is easily adsorbed, and in some cases, the resistance of the outermost surface is lowered, which may cause problems such as image flow. In order to reduce these image defects, the amine compound described in Patent Document 1 is effective. However, the ability to prevent image blur and image flow is insufficient during repeated image formation at high temperature and high humidity. It was.

  Therefore, as a result of further investigation, there is a problem of image blur and image flow even in repeated image formation under high temperature and high humidity by including a compound having a specific structure represented by the following general formula (1) in the protective layer. It was found that can be solved. The reason for this has not been clarified at this time, but it effectively suppresses the generation of radical substances that easily accumulate in the structure of the substituted amino group contained in the structure of the heterogeneous particles, and suppresses the adsorption of oxidizing gases, etc. It is presumed that

In the general formula (1), A and B are groups selected from the following (i) and (ii), and may be the same or different.
(I) _-CH 2 X
_(Ii) -CH 2 _CH 2 Y
However, X and Y each represent an aromatic residue that may have a substituent, a cycloalkyl group that may have a substituent, or a heterocycloalkyl group that may have a substituent.

  The amount of the compound represented by the general formula (1) is preferably 0.01 to 50% by weight with respect to the binder resin described later. If it is less than 0.01% by weight, the resistance to the oxidizing gas is insufficient, and if it exceeds 50% by weight, the film strength is lowered and the wear resistance is deteriorated.

  In the compound represented by the general formula (1), the amine compounds (2) to (10) represented by the following chemical formulas (2) to (10) are preferable because they have excellent resistance to the oxidizing gas. In particular, the amine compound (2) or the amine compound (3) is preferable.

Further, the electrophotographic photoreceptor according to the present invention will be described with reference to the drawings.
In FIG. 1, a photosensitive layer 33 mainly composed of a charge generation material and a charge transport material is provided on a conductive support 31, and a protective layer 39 is further provided on the surface of the photosensitive layer. In this case, the protective layer 39 contains fluororesin fine particles and the compound represented by the general formula (1).

  FIG. 2 shows a structure in which a charge generation layer 35 mainly composed of a charge generation material and a charge transport layer 37 mainly composed of a charge transport material are laminated on a conductive support 31. A protective layer 39 is provided on the transport layer. In this case, the protective layer 39 contains fluororesin fine particles and the compound represented by the general formula (1).

  In FIG. 3, an undercoat layer 41, a charge generation layer 35, a charge transport layer 37, and a protective layer 39 are sequentially provided on a conductive support 31. In this case, the protective layer 39 contains fluororesin fine particles and the compound represented by the general formula (1).

(Conductive support)
Examples of the conductive support 31 include those having a volume resistance of 10 ¹⁰ Ω · cm or less, for example, metals such as aluminum, nickel, chromium, nichrome, copper, gold, silver, platinum, tin oxide, indium oxide, etc. The metal oxide of the above is coated with film or cylindrical plastic or paper by vapor deposition or sputtering, or a plate made of aluminum, aluminum alloy, nickel, stainless steel or the like and extruded by drawing or drawing. After pipe formation, surface treatment pipes such as cutting, superfinishing, and polishing can be used. An endless nickel belt, an endless stainless steel belt, or the like can also be used as the conductive support 31.

  In addition to this, the conductive support dispersed in the present invention can also be used as the conductive support 31 in the present invention in which conductive powder is dispersed in an appropriate binder resin and coated to provide a conductive layer. Examples of the conductive powder include carbon black and acetylene black; metal powder such as aluminum, nickel, iron, nichrome, copper, zinc and silver; metal oxide powder such as conductive tin oxide and ITO.

  The binder resin used at the same time is polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer. , Polyvinyl acetate, polyvinylidene chloride, polyarylate resin, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly-N-vinyl carbazole, acrylic resin, silicone resin, epoxy resin, Thermoplastic, thermosetting resins, and photocurable resins such as melamine resin, urethane resin, phenol resin, and alkyd resin can be used. Such a conductive layer can be provided by dispersing and applying these conductive powder and binder resin in a suitable solvent such as tetrahydrofuran, methyl ethyl ketone, or toluene.

  Furthermore, it is electrically conductive by a heat-shrinkable tube in which the conductive powder is contained in a material such as polyvinyl chloride, polypropylene, polyester, polystyrene, polyvinylidene chloride, polyethylene, chlorinated rubber, Teflon (registered trademark) on a suitable cylindrical substrate. Those provided with a conductive layer can also be used favorably as the conductive support 31 of the present invention.

(Photosensitive layer)
Next, the photosensitive layer will be described. The photosensitive layer may be a single layer or a laminate, but for convenience of explanation, first, a case of a laminate composed of the charge generation layer 35 and the charge transport layer 37 will be described.

<Charge generation layer>
The charge generation layer 35 is a layer mainly composed of a charge generation material. A known charge generation material can be used for the charge generation layer 35, and representative examples thereof include monoazo pigments, disazo pigments, trisazo pigments, perylene pigments, perinone pigments, quinacridone pigments, and quinone condensed polycycles. Examples thereof include compounds, squalic acid dyes, phthalocyanine pigments, naphthalocyanine pigments, and azulenium salt dyes. These charge generation materials may be used alone or in combination of two or more.

  In the charge generation layer 35, a charge generation material is dispersed in a suitable solvent together with a binder resin as necessary using a ball mill, an attritor, a sand mill, an ultrasonic wave, etc., and this is applied onto the conductive support 31. It is formed by drying.

As the binder resin used for the charge generation layer 35 as necessary, polyamide, polyurethane, epoxy resin, polyketone, polycarbonate, silicone resin, acrylic resin, polyvinyl butyral, polyvinyl formal, polyvinyl ketone, polystyrene, polysulfone, poly-N -Vinylcarbazole, polyacrylamide, polyvinyl benzal, polyester, phenoxy resin, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyphenylene oxide, polyamide, polyvinyl pyridine, cellulose resin, casein, polyvinyl alcohol, polyvinyl pyrrolidone, etc. Can be mentioned.
The amount of the binder resin is suitably 0 to 500 parts by weight, preferably 10 to 300 parts by weight with respect to 100 parts by weight of the charge generating material. The binder resin may be added before or after dispersion.

  As the solvent used here, isopropanol, acetone, methyl ethyl ketone, cyclohexanone, tetrahydrofuran, ethyl cellosolve, ethyl acetate, methyl acetate, cyclohexane, toluene, xylene, ligroin and other ketone solvents, ester solvents, ether solvents are preferable. used. These may be used alone or in combination of two or more.

The charge generation layer 35 is mainly composed of a charge generation material, a solvent, and a binder resin, and may include additives such as a sensitizer, a dispersant, a surfactant, and silicone oil. good.
As a coating method for the coating solution, a dip coating method, spray coating, beat coating, nozzle coating, spinner coating, ring coating, or the like can be used.
The thickness of the charge generation layer 35 is suitably about 0.01 to 5 μm, preferably 0.1 to 2 μm.

<Charge transport layer>
The charge transport layer 37 can be formed by dissolving or dispersing a charge transport material and a binder resin in a suitable solvent, and applying and drying the solution on the charge generation layer 35. Further, if necessary, two or more kinds of plasticizers, leveling agents, antioxidants and the like can be added.

Charge transport materials include hole transport materials and electron transport materials.
Examples of the electron transporting material include chloroanil, bromoanil, tetracyanoethylene, tetracyanoquinodimethane, 2,4,7-trinitro-9-fluorenone, 2,4,5,7-tetranitro-9-fluorenone, 2,4 , 5,7-tetranitroxanthone, 2,4,8-trinitrothioxanthone, 2,6,8-trinitro-4H-indeno [1,2-b] thiophen-4-one, 1,3,7-tri Examples thereof include electron-accepting substances such as nitrodibenzothiophene-5,5-dioxide and benzoquinone derivatives.
Examples of the hole transport material include poly-N-vinylcarbazole and derivatives thereof, poly-γ-carbazolylethyl glutamate and derivatives thereof, pyrene-formaldehyde condensates and derivatives thereof, polyvinylpyrene, polyvinylphenanthrene, polysilane, oxazole derivatives, Oxadiazole derivatives, imidazole derivatives, monoarylamine derivatives, diarylamine derivatives, triarylamine derivatives, stilbene derivatives, α-phenylstilbene derivatives, benzidine derivatives, diarylmethane derivatives, triarylmethane derivatives, 9-styrylanthracene derivatives, pyrazolines Derivatives, divinylbenzene derivatives, hydrazone derivatives, indene derivatives, butadiene derivatives, pyrene derivatives, bisstilbene derivatives, enamine derivatives, etc. Other known materials may be used.
These charge transport materials may be used alone or in combination of two or more.

  As the binder resin, polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, Polyvinylidene chloride, polyarylate resin, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly-N-vinyl carbazole, acrylic resin, silicone resin, epoxy resin, melamine resin, urethane resin And thermoplastic and thermosetting resins such as phenol resins and alkyd resins.

The amount of the charge transport material is appropriately 20 to 300 parts by weight, preferably 40 to 150 parts by weight, based on 100 parts by weight of the binder resin.
The thickness of the charge transport layer 37 is preferably 25 μm or less from the viewpoint of resolution and responsiveness. The lower limit varies depending on the system to be used (particularly charging potential), but is preferably 5 μm or more.

  As the solvent used here, tetrahydrofuran, toluene, cyclohexanone, cyclopentanone, methyl ethyl ketone, acetone or the like is used. These may be used alone or in combination of two or more.

  As a coating method of the coating liquid obtained as described above, conventional coating methods such as dip coating, spray coating, beat coating, nozzle coating, spinner coating, ring coating, and the like can be used.

<Single layer photosensitive layer>
Next, the case where the photosensitive layer has a single layer structure, that is, the photosensitive layer 33 will be described.
A photosensitive layer 33 in which the above-described charge generation material and charge transport material are dispersed in a binder resin can be used. The photosensitive layer 33 can be formed by dissolving or dispersing a charge generating substance, a charge transporting substance and a binder resin in a suitable solvent, and applying and drying them. Moreover, a plasticizer, a leveling agent, antioxidant, etc. can also be added as needed.
As the binder resin, in addition to the binder resin previously mentioned in the charge transport layer 37, the binder resin mentioned in the charge generation layer 35 may be mixed and used.
The amount of the charge generating material is preferably 5 to 40 parts by weight, and the amount of the charge transporting material is preferably 0 to 190 parts by weight, and more preferably 50 to 150 parts by weight with respect to 100 parts by weight of the binder resin.
The photosensitive layer 33 is formed by dip coating, spray coating, bead coating, or the like by applying a coating solution in which a charge generating material and a binder resin are dispersed together with a charge transport material using a solvent such as tetrahydrofuran, dioxane, dichloroethane, and cyclohexane. It can be formed by coating with a ring coat or the like. The film thickness of the photosensitive layer 33 is suitably about 5 to 25 μm.

<Underlayer>
In the electrophotographic photoreceptor of the present invention, an undercoat layer 41 can be provided between the conductive support 31 and the photosensitive layer. The undercoat layer 41 generally contains a resin as a main component. However, considering that the photosensitive layer is coated with a solvent on these resins, the undercoat layer 41 is a resin having a high solvent resistance with respect to a general organic solvent. Is desirable. Examples of such resins include water-soluble resins such as polyvinyl alcohol, casein, and sodium polyacrylate, alcohol-soluble resins such as copolymer nylon and methoxymethylated nylon, polyurethane, melamine resin, phenol resin, alkyd-melamine resin, and epoxy. Examples thereof include a curable resin that forms a three-dimensional network structure such as a resin.

The undercoat layer 41 may be added with fine powder pigments of metal oxides exemplified by titanium oxide, silica, alumina, zirconium oxide, tin oxide, indium oxide, etc. in order to prevent moire and reduce residual potential. .
These undercoat layers 41 can be formed using an appropriate solvent and coating method as in the above-described photosensitive layer.
Furthermore, in the present invention, a silane coupling agent, a titanium coupling agent, a chromium coupling agent, or the like can be used as the undercoat layer 41.
In addition, in the present invention, the undercoat layer 41 has an anodization of Al ₂ O ₃ , an organic material such as polyparaxylylene (parylene), SiO ₂ , SnO ₂ , TiO ₂ , ITO, CeO. What provided ₂ etc. inorganic substances by the vacuum thin film preparation method can also be used satisfactorily.
In addition, known ones can be used.
The thickness of the undercoat layer is suitably from 0.3 to 10 μm.

《Protective layer》
In the electrophotographic photoreceptor of the present invention, a protective layer 39 is provided on the photosensitive layer for the purpose of protecting the photosensitive layer and maintaining a low surface friction coefficient. At this time, as shown in FIGS. 1, 2, and 3, the protective layer 39 is provided on the outermost surface layer of the electrophotographic photosensitive member.

  The binder resin used for the protective layer 39 is ABS resin, ACS resin, olefin-vinyl monomer copolymer, chlorinated polyether, aryl resin, phenol resin, polyacetal, polyamide, polyamideimide, polyacrylate, polyallylsulfone. , Polybutylene, polybutylene terephthalate, polycarbonate, polyethersulfone, polyethylene, polyethylene terephthalate, polyimide, acrylic resin, polymethylbenten, polypropylene, polyphenylene oxide, polysulfone, polystyrene, polyarylate, AS resin, butadiene-styrene copolymer, polyurethane , Resins such as polyvinyl chloride, polyvinylidene chloride, and epoxy resin. From the viewpoint of dispersibility of fluororesin fine particles, residual potential, and coating film defects, polycarbonate or polyarylate is particularly effective and useful.

  Examples of fluororesin fine particles that can be used in the present invention include tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer resin fine particles (PFA), tetrafluoroethylene resin fine particles (PTFE), perfluoroalkoxy resin fine particles, and three fluorocarbons. Chlorinated ethylene chloride resin fine particles, hexafluoroethylene propylene resin fine particles, vinyl fluoride resin fine particles, vinylidene fluoride resin fine particles, fluorinated ethylene dichloride resin fine particles and copolymers thereof, and the like. One kind or two or more kinds are appropriately selected, and tetrafluoroethylene resin fine particles and perfluoroalkoxy resin fine particles are particularly preferable.

  The particle size can be 0.1 to 10 μm, preferably 0.05 to 2.0 μm, and the particle size can be adjusted by a dispersion treatment described later as required.

The size of the secondary particle diameter of the fluororesin fine particles in the protective layer 39 is preferably 0.3 to 4 μm, and more preferably the size of the secondary particles is 0.3 to 1.5 μm.
If the secondary particle diameter exceeds 4 μm, the toner contact surface may be insufficient, or an abnormal image may be caused by scattering of laser light. When the secondary particle diameter is less than 0.3 μm, the effect of reducing the surface friction coefficient of the electrophotographic photosensitive member becomes insufficient.

  Moreover, it is necessary to coat | cover the surface in 12 to 33% of range by area ratio. When the surface coverage is less than 12% in area ratio, the low surface friction coefficient when viewed microscopically becomes insufficient, and when the area ratio exceeds 33%, the transmittance of laser light is significantly reduced, It becomes difficult to form an electrostatic latent image.

  Furthermore, in order to maintain a low surface friction coefficient even after repeated use, it is preferable that the fluororesin fine particles are present in a volume fraction of 20% to 60%. As a result, a necessary and sufficient amount of fluororesin fine particles continues to be extended even on a photoconductor having a significantly reduced amount of wear due to a low friction coefficient, so that a low surface friction coefficient and high durability are exhibited. If the volume fraction is less than 20%, the surface area of the protective layer 39 can secure the above-mentioned coverage, but when the inside of the protective layer 39 is exposed to the surface due to wear, the low surface friction coefficient is not expressed. End up. On the other hand, if the volume fraction exceeds 60%, the amount of the binder resin is reduced, so that the mechanical strength of the coating film is remarkably lowered and the life of the photoreceptor is reduced.

  As the solvent to be used, all solvents used in the charge transport layer 37 such as tetrahydrofuran, toluene, cyclohexanone, cyclopentanone, methyl ethyl ketone, and acetone can be used. However, a solvent having a high viscosity is preferable at the time of dispersion, but a solvent having high volatility is preferable at the time of coating. When there is no solvent satisfying these conditions, it is possible to use a mixture of two or more solvents having respective physical properties, which may have a great effect on the dispersibility of the fluororesin fine particles. A mixed solvent of tetrahydrofuran, cyclohexanone, and cyclopentanone is particularly preferable.

  The fluororesin fine particles can be dispersed together with at least an organic solvent using a conventional method such as an attritor, a sand mill, a vibration mill, or an ultrasonic wave. Among these, dispersion by a ball mill or a vibration mill in which impurities from the outside are little mixed is more preferable from the viewpoint of dispersibility. As the material of the media used, all media such as zirconia, alumina, and agate that have been used in the past can be used. However, zirconia is particularly preferable from the viewpoint of the effect on the dispersibility of the fluororesin fine particles. More preferred. In some cases, dispersibility may be further increased by combining these dispersion methods.

Further, a dispersant may be added to the resin for the purpose of controlling the dispersibility of the fluororesin fine particles. As such a dispersant, a fluorine-based surfactant, a graft polymer, a block polymer, a coupling agent, and the like can be used. In the present invention, a known material can be used as the fluorosurfactant.
For example, as a copolymer containing (1) a (meth) acrylate having a fluoroalkyl group described in paragraph No. [0017] of JP-A-07-068398, for example, JP-A-60-212410 and JP-A No. A block copolymer comprising a fluorine-free vinyl monomer and a fluorine-containing vinyl monomer described in JP-A-60-228588, and (2) a fluorine-based graft polymer, for example, described in JP-A-60-187721 Examples thereof include a comb-type graft polymer obtained by copolymerizing a methacrylate macromonomer having polymethyl methacrylate in the side chain and a (meth) acrylate having a fluoroalkyl group. These fluororesins are commercially available as paint additives.
As the fluorine-containing block copolymer, Modiper F series (for example, F100, F110, F200, commercially available from Nippon Oil & Fats Co., Ltd.) as a block copolymer comprising a fluoroalkyl group-containing polymer segment and an acrylic polymer segment. F210, F2020).
The fluorine-based graft polymer is commercially available from Toa Gosei Co., Ltd. under the names Aron GF-150 and GF-300.
These fluorosurfactants may be used alone or as a crosslinked resin component.

  Further, a filler may be added to the protective layer 39 of the photoreceptor for the purpose of improving the wear resistance. As the filler, there are an organic filler and an inorganic filler. From the viewpoint of the hardness of the filler, the use of the inorganic filler is advantageous for improving the wear resistance. Examples of such inorganic filler materials include metal powders such as copper, tin, aluminum, and indium, silica, tin oxide, zinc oxide, titanium oxide, alumina, zirconium oxide, indium oxide, antimony oxide, bismuth oxide, calcium oxide, Examples thereof include metal oxides such as tin oxide doped with antimony and indium oxide doped with tin, metal fluorides such as tin fluoride, calcium fluoride, and aluminum fluoride, and inorganic materials such as potassium titanate and boron nitride.

  These fillers can be surface-treated with at least one surface treatment agent, and it is preferable to do so from the viewpoint of dispersibility of the filler. Decreasing the dispersibility of the filler not only increases the residual potential, but also decreases the transparency of the coating, causes defects in the coating, and decreases the wear resistance. It can develop into a big problem.

  As the surface treatment agent, all conventionally used surface treatment agents can be used, but a surface treatment agent capable of maintaining the insulating properties of the filler is preferable. For example, a titanate coupling agent, an aluminum coupling agent, a zircoaluminate coupling agent, a higher fatty acid, or a mixture treatment of these with a silane coupling agent is more preferable from the viewpoint of filler dispersibility and image blurring. . The treatment with the silane coupling agent is strongly influenced by image blur, but the influence may be suppressed by performing a mixing treatment of the surface treatment agent and the silane coupling agent.

  The surface treatment amount varies depending on the average primary particle size of the filler used, but is preferably 3 to 30 wt%, more preferably 5 to 20 wt%. If the surface treatment amount is less than this, the filler dispersion effect cannot be obtained, and if it is too much, the residual potential is significantly increased.

  In addition, the addition of the charge transporting material (low molecular charge transporting material or high molecular charge transporting material) mentioned in the charge transporting layer 37 to the protective layer 39 is effective and useful for reducing the residual potential and improving the image quality. .

  As a method for forming the protective layer 39, conventional methods such as dip coating, spray coating, beat coating, nozzle coating, spinner coating, ring coating and the like can be used. More preferred. Furthermore, it is possible to apply the required film thickness of the protective layer 39 at a time to form the protective layer 39, but it is more preferable that the protective layer 39 is formed in multiple layers by applying two or more layers. More preferable from the viewpoint of the uniformity of the fluororesin fine particles. The thickness of the protective layer 39 can be set freely. However, when the thickness of the protective layer 39 is significantly increased, the image quality tends to be slightly deteriorated. Therefore, it is preferable to set the thickness to the minimum necessary.

[Electrophotographic method, electrophotographic apparatus]
Next, the electrophotographic method and the electrophotographic apparatus of the present invention will be described in detail with reference to the drawings.
FIG. 4 is a schematic diagram for explaining the electrophotographic method and the electrophotographic apparatus of the present invention, and the following examples also belong to the category of the present invention.

In FIG. 4, an electrophotographic photoreceptor 1 is the above-described electrophotographic photoreceptor according to the present invention.
The photosensitive member 1 has a drum shape, but may be a sheet shape or an endless belt shape.

  A charging charger 3 as a charging means, a pre-transfer charger 7, a transfer charger 10 constituting a part of the transfer means, a separation charger 11 constituting a part of the transfer means, and a pre-cleaning charger 13 include corotron, scorotron, solid charging A device (solid state charger), a charging roller, or the like is used, and all known means can be used.

  As the transfer means, the above charger can be generally used. However, as shown in FIG. 4, a combination of the transfer charger 10 and the separation charger 11 is effective.

  Further, the light source such as the image exposure unit 5 serving as an exposure unit and the neutralization lamp 2 serving as a neutralization unit includes a fluorescent lamp, a tungsten lamp, a halogen lamp, a mercury lamp, a sodium lamp, a light emitting diode (LED), a semiconductor laser (LD), Although light emitting materials such as electroluminescence (EL) in general can be used, a light emitting diode (LED) and a semiconductor laser (LD) are preferable. Various types of filters such as a sharp cut filter, a band pass filter, a near infrared cut filter, a dichroic filter, an interference filter, and a color temperature conversion filter can be used to irradiate only light in a desired wavelength range.

  In addition to the steps shown in FIG. 4, the light source or the like provides a process such as a transfer process, a static elimination process, a cleaning process, or a pre-exposure using light irradiation, so that the photoreceptor 1 is irradiated with light.

The toner (toner image) developed on the photosensitive member 1 by the developing unit 6 as a developing means is transferred to a transfer paper (recording material) 9, but not all is transferred. Toner remaining on the top is also generated. Such toner is removed from the photoreceptor by cleaning means, for example, fur brush 14 and blade 15. Cleaning may be performed only with a cleaning brush, and a known brush such as a fur brush or a mag fur brush is used as the cleaning brush.
The transferred unfixed toner image is conveyed to a fixing device 8 as fixing means while being held on the transfer paper 9, and is fixed to the transfer paper 9 by heat and pressure. The fixing device 9 is not limited to heat and pressure, and all known and conventional means can be used.

  Further, 4 is an eraser (static elimination), and 12 is a separation claw for preventing the transfer paper from entering the cleaning portion.

When the electrophotographic photoreceptor 1 is positively (negatively) charged and image exposure is performed, a positive (negative) electrostatic latent image is formed on the surface of the photoreceptor 1. A positive image can be obtained by developing this with negative (positive) toner (electrodetection fine particles), and a negative image can be obtained by developing with positive (negative) toner.
A known method is applied to the developing unit, and a known method is also used for the charge eliminating unit.

  FIG. 5 shows another example of the electrophotographic method according to the present invention. The electrophotographic photosensitive member 21 is the above-described electrophotographic photosensitive member according to the present invention. The electrophotographic photosensitive member 21 is driven by driving rollers 22a and 22b, and is charged by a charger 23 as a charging unit, and image exposure and developing unit by a light source 24 as an exposure unit. Development (not shown), transfer using a charger 25 as a transfer means, exposure before cleaning with a light source 26, cleaning with a brush 27 as a cleaning means, and static elimination with a light source 28 as a static elimination means. In FIG. 5, light exposure for pre-cleaning exposure is performed on the photosensitive member 21 (of course, in this case, the conductive support is translucent) from the conductive support side.

  The above illustrated electrophotographic process is illustrative of an embodiment of the present invention, and of course other embodiments are possible. For example, in FIG. 5, the pre-cleaning exposure is performed from the conductive support side, but this may be performed from the photosensitive layer side, or image exposure and neutralization light irradiation may be performed from the conductive support side. . On the other hand, the light irradiation process is illustrated as image exposure, pre-cleaning exposure, and static elimination exposure. In addition, a pre-transfer exposure, a pre-exposure of image exposure, and other known light irradiation processes are provided to light the photosensitive member. Irradiation can also be performed.

The electrophotographic apparatus preferably has a fluororesin fine particle deformation / extension member that contacts and rubs at least the surface of the electrophotographic photosensitive member.
As the fluororesin fine particle deformation / extension member, a contact member for the purpose of rubbing the exposed portion of the fluororesin fine particles may be provided, a contact charging member such as a charging roller, a cleaning member such as a cleaning blade or a cleaning brush, A mechanism for applying pressure to a member generally used in an electrophotographic apparatus such as a transfer member such as a transfer belt or an intermediate transfer belt may be provided. Here, a case where the surface of the photoreceptor is rubbed with a cleaning blade will be described as an example. The cleaning blade is preferable because it has a great effect of rubbing almost the entire surface while pressing the surface of the photosensitive member with a substantially uniform pressure to uniformly attach the fluororesin fine particles to the surface.

As a result, the effect of lowering the friction coefficient is remarkably increased, and the cleaning property and wear resistance are remarkably increased. Although this effect is not clearly understood, the following mechanism is conceivable.
When the fluororesin fine particle deformation / extension member rubs the outermost surface layer (protective layer 39) where the fluororesin fine particles are exposed, the exposed portions of the fluororesin fine particles extend in the rubbing direction (deform and extend). Further, the surface of the photoreceptor without the fluororesin fine particles is also coated. At this time, as the outermost surface layer of the electrophotographic photosensitive member of the present invention, the fluororesin fine particles are present in a suitable range, so that the surface on which the fluororesin fine particles are not present can be obtained without increasing the content of the fluororesin fine particles. Since it can be coated over the entire area, a low friction coefficient can be expressed almost uniformly over the entire surface of the photoreceptor. In addition, even if the outermost layer wears out, the inner fluororesin fine particles are precipitated, so it is possible to maintain a surface with a low coefficient of friction over a long period of time, and to achieve a high level of cleaning and wear resistance. Can be maintained.

When coating fluororesin fine particles with a cleaning blade, various conditions of the cleaning blade include a blade contact angle of 10 to 30 degrees, a contact pressure of 0.3 to 4 g / mm, and a rubber hardness of urethane rubber used as the blade of 60 to 70 degrees. Rebound resilience, 30 to 70%, Young's modulus of 30 to 60 kgf / cm ² , thickness of 1.5 to 3.0 mm, free length of 7 to 12 mm, blade edge biting into the photoreceptor in a range of 0.2 to 2 mm Is preferred.

  Further, although not shown in the above-described electrophotographic apparatus, the developing unit forms one or more toner images, the transfer unit includes a primary transfer unit, an intermediate transfer member (such as an intermediate transfer belt), A secondary transfer portion, wherein the primary transfer portion primarily transfers the toner image developed on the electrophotographic photosensitive member onto the intermediate transfer member, and the secondary transfer portion is located on the intermediate transfer member. When a toner image is secondarily transferred onto a recording material, and the developing unit forms two or more toner images, the primary transfer unit stacks the two or more toner images on the intermediate transfer member. The secondary transfer unit may perform secondary transfer of the two or more toner images stacked on the intermediate transfer member on the recording material in a lump. That is, such a configuration is a so-called intermediate transfer type electrophotographic apparatus, and can be realized by applying a known and commonly used intermediate transfer apparatus to the above-described electrophotographic apparatus. Here, the two or more toner images can be realized as full-color images, for example, by using toner images of four colors of YMCK.

The electrophotographic apparatus as described above may be fixedly incorporated in a copying apparatus, a facsimile, or a printer, but may be incorporated in these apparatuses in the form of a process cartridge.
There are many shapes and the like of the process cartridge, but a general example is shown in FIG. The process cartridge shown in FIG. 6 incorporates the above-described electrophotographic photosensitive member according to the present invention, and further includes a charging charger 17 as a charging means, a developing roller 20 as a developing means, and a cleaning brush 18 as a cleaning means. One device (component). In addition, the process cartridge may include other means such as an exposure unit, a transfer unit, and a charge removal unit. In this embodiment, light emitted from an exposure means (not shown) enters the process cartridge from the image exposure unit 19 and exposes the electrophotographic photosensitive member 16.

〔toner〕
Next, an example of a toner by a polymerization method that is preferably used in the electrophotographic apparatus will be described. Needless to say, the following example is a preferred embodiment, and the toner used in the present invention is not limited to the toner produced by the polymerization method, but produced by other known methods such as a pulverization method. It may be toner.

The polymerized toner suitably used in the present invention is obtained by dissolving or dispersing at least a polymer having a site capable of reacting with a compound having an active hydrogen group, a polyester, a colorant, and a release agent in an organic solvent. The toner material liquid is obtained by crosslinking and / or elongation reaction in an aqueous solvent.
In the following, a constituent material and a manufacturing method of a polymerized toner (hereinafter sometimes simply referred to as toner) will be described.

(Modified polyester)
The toner used in the present invention contains a modified polyester (i) that is a polymer as a binder resin.
The modified polyester (i) refers to a polyester resin in which a linking group other than an ester bond is present, or a resin component having a different structure in the polyester resin bonded through a covalent bond or an ionic bond.
Specifically, the polyester terminal is modified by introducing a functional group such as a carboxylic acid group or an isocyanate group that reacts with a hydroxyl group into the polyester terminal and further reacting with an active hydrogen-containing compound.

  Examples of the modified polyester (i) include urea-modified polyester obtained by a reaction between a polyester prepolymer (A) having an isocyanate group and amines (B).

  As the polyester prepolymer (A) having an isocyanate group, a polyester having a polycondensate of a polyhydric alcohol (PO) and a polyvalent carboxylic acid (PC) and having an active hydrogen group is further added to a polyvalent isocyanate compound (PIC). And those reacted with.

  Examples of the active hydrogen group possessed by the polyester include a hydroxyl group (alcoholic hydroxyl group and phenolic hydroxyl group), an amino group, a carboxyl group, a mercapto group, and the like. Among these, an alcoholic hydroxyl group is preferable.

The urea-modified polyester is produced as follows.
Examples of the polyhydric alcohol compound (PO) include dihydric alcohol (DIO) and trihydric or higher polyhydric alcohol (TO). (DIO) alone or a mixture of (DIO) and a small amount of (TO) preferable.

Examples of the dihydric alcohol (DIO) include alkylene glycol (ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, etc.); alkylene ether glycol (diethylene glycol) , Triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, etc.); alicyclic diols (1,4-cyclohexanedimethanol, hydrogenated bisphenol A, etc.); bisphenols (bisphenol A, bisphenol) F, bisphenol S, etc.); alkylene oxide (ethylene oxide, propylene oxide, butylene oxide, etc.) adduct of the above alicyclic diol; Alkylene oxide bisphenol (ethylene oxide, propylene oxide, butylene oxide, etc.), etc. adducts.
Of these, preferred are alkylene glycols having 2 to 12 carbon atoms or alkylene oxide adducts of bisphenols, and particularly preferred are alkylene oxide adducts of bisphenols and alkylene glycols having 2 to 12 carbon atoms. It is a combined use.

  The trihydric or higher polyhydric alcohol (TO) includes 3 to 8 or higher polyhydric aliphatic alcohols (glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol, etc.); trihydric or higher phenols (Trisphenol PA, phenol novolak, cresol novolak, etc.); and alkylene oxide adducts of the above trivalent or higher polyphenols.

  Examples of the polyvalent carboxylic acid (PC) include divalent carboxylic acid (DIC) and trivalent or higher polyvalent carboxylic acid (TC). (DIC) alone or (DIC) and a small amount of (TC) Mixtures are preferred.

Divalent carboxylic acids (DIC) include alkylene dicarboxylic acids (succinic acid, adipic acid, sebacic acid, etc.); alkenylene dicarboxylic acids (maleic acid, fumaric acid, etc.); aromatic dicarboxylic acids (phthalic acid, isophthalic acid, terephthalic acid) And naphthalenedicarboxylic acid).
Among these, preferred are alkenylene dicarboxylic acids having 4 to 20 carbon atoms or aromatic dicarboxylic acids having 8 to 20 carbon atoms.

Examples of the trivalent or higher polyvalent carboxylic acid (TC) include aromatic polycarboxylic acids having 9 to 20 carbon atoms (such as trimellitic acid and pyromellitic acid).
In addition, as polyhydric carboxylic acid (PC), you may make it react with polyhydric alcohol (PO) using the above-mentioned acid anhydride or lower alkyl ester (Methyl ester, ethyl ester, isopropyl ester, etc.).

The ratio of the polyhydric alcohol (PO) to the polycarboxylic acid (PC) is usually 2/1 to 1/1, preferably as the equivalent ratio [OH] / [COOH] of the hydroxyl group [OH] and the carboxyl group [COOH]. Is 1.5 / 1 to 1/1, more preferably 1.3 / 1 to 1.02 / 1.
Examples of the polyvalent isocyanate compound (PIC) include aliphatic polyisocyanates (tetramethylene diisocyanate, hexamethylene diisocyanate, 2,6-diisocyanatomethylcaproate, etc.); alicyclic polyisocyanates (isophorone diisocyanate, cyclohexylmethane diisocyanate, etc.) Aromatic diisocyanates (tolylene diisocyanate, diphenylmethane diisocyanate, etc.); araliphatic diisocyanates (α, α, α ′, α′-tetramethylxylylene diisocyanate, etc.); isocyanates; Those blocked with caprolactam or the like; and combinations of two or more of these.

The ratio of the polyvalent isocyanate compound (PIC) is usually 5/1 to 1/1, preferably as an equivalent ratio [NCO] / [OH] of the isocyanate group [NCO] and the hydroxyl group [OH] of the polyester having a hydroxyl group. 4/1 to 1.2 / 1, more preferably 2.5 / 1 to 1.5 / 1.
If [NCO] / [OH] exceeds 5, low-temperature fixability deteriorates, which is not preferable. When the molar ratio of [NCO] is less than 1, when a urea-modified polyester is used, the urea content in the ester becomes low and the hot offset resistance deteriorates, which is not preferable.

The content of the polyvalent isocyanate compound (PIC) component in the polyester prepolymer (A) having an isocyanate group is usually 0.5 to 40% by mass, preferably 1 to 30% by mass, more preferably 2 to 20% by mass. %.
If it is less than 0.5% by mass, the hot offset resistance is deteriorated and it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability. On the other hand, if it exceeds 40% by mass, the low-temperature fixability is deteriorated.

The number of isocyanate groups contained per molecule in the polyester prepolymer (A) having an isocyanate group is usually 1 or more, preferably 1.5 to 3 on average, more preferably 1.8 to 2 on average. Five.
When the number is less than 1 per molecule, the molecular weight of the urea-modified polyester is lowered, and the hot offset resistance is deteriorated, which is not preferable.

  Next, as amines (B) to be reacted with the polyester prepolymer (A), a divalent amine compound (B1), a trivalent or higher polyvalent amine compound (B2), an amino alcohol (B3), an amino mercaptan (B4) ), Amino acid (B5), and amino acid block of B1 to B5 (B6).

  Examples of the divalent amine compound (B1) include aromatic diamines (phenylenediamine, diethyltoluenediamine, 4,4′-diaminodiphenylmethane, etc.); alicyclic diamines (4,4′-diamino-3,3′-dimethyldicyclohexyl). Methane, diamine cyclohexane, isophorone diamine, etc.); and aliphatic diamines (ethylene diamine, tetramethylene diamine, hexamethylene diamine, etc.) and the like.

  Examples of the trivalent or higher polyvalent amine compound (B2) include diethylenetriamine and triethylenetetramine.

  Examples of amino alcohol (B3) include ethanolamine and hydroxyethylaniline.

  Examples of amino mercaptan (B4) include aminoethyl mercaptan and aminopropyl mercaptan.

  Examples of the amino acid (B5) include aminopropionic acid and aminocaproic acid.

  Examples of the compound (B6) obtained by blocking the amino group of B1 to B5 include ketimine compounds and oxazolidine compounds obtained from the amines of B1 to B5 and ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.).

  Among these amines (B), B1 or a mixture of B1 and a small amount of B2 is preferable.

The ratio of amines (B) is equivalent to the equivalent ratio [NCO] / [NHx] of isocyanate groups [NCO] in the polyester prepolymer (A) having isocyanate groups and amino groups [NHx] in amines (B). Is usually 1/2 to 2/1, preferably 1.5 / 1 to 1 / 1.5, more preferably 1.2 / 1 to 1 / 1.2.
When [NCO] / [NHx] is more than 2 or less than 1/2, the molecular weight of the urea-modified polyester is lowered, and the hot offset resistance is deteriorated.

The urea-modified polyester may contain a urethane bond together with a urea bond.
The molar ratio of the urea bond content to the urethane bond content is usually 100/0 to 10/90, preferably 80/20 to 20/80, and more preferably 60/40 to 30/70.
If the molar ratio of the urea bond is less than 10%, the hot offset resistance deteriorates, which is not preferable.

  The modified polyester (i) used in the present invention is produced by a one-shot method or a prepolymer method.

The mass average molecular weight of the modified polyester (i) is usually 10,000 or more, preferably 20,000 to 10,000,000, and more preferably 30,000 to 1,000,000.
The peak molecular weight at this time is preferably 1000 to 10000, and if it is less than 1000, the elongation reaction is difficult, the elasticity of the toner is small, and as a result, the hot offset resistance is deteriorated. On the other hand, if it exceeds 10,000, various problems in production (productivity, etc.) may occur due to a decrease in fixability and particle formation or pulverization.

The number average molecular weight of the modified polyester (i) is not particularly limited when the unmodified polyester (ii) described later is used, and may be a number average molecular weight that can be easily obtained to obtain the mass average molecular weight.
(I) When used alone, the number average molecular weight is usually 20000 or less, preferably 1000 to 10000, and more preferably 2000 to 8000. Exceeding 20000 is not preferable because low-temperature fixability and gloss when used in a full-color apparatus deteriorate.

In the crosslinking and / or extension reaction between the polyester prepolymer (A) and the amines (B) to obtain the modified polyester (i), a reaction terminator is used as necessary to adjust the molecular weight of the resulting urea-modified polyester. be able to.
Examples of the reaction terminator include monoamines (diethylamine, dibutylamine, butylamine, laurylamine, etc.), and those obtained by blocking them (ketimine compounds).

(Unmodified polyester)
In the present invention, not only the modified polyester (i) is used alone, but also the unmodified polyester (ii) can be contained as a binder resin component together with the (i).
By using (ii) in combination, the low-temperature fixability and the gloss when used in a full-color device are improved, which is preferable to single use.

Examples of (ii) include polycondensates of polyhydric alcohol (PO) and polyvalent carboxylic acid (PC) similar to the polyester component of (i) above, and preferred ones are also the same as (i). .
(Ii) is not limited to unmodified polyester, but may be modified with a chemical bond other than a urea bond, and may be modified with a urethane bond, for example.

It is preferable that (i) and (ii) are at least partially compatible with each other in terms of low-temperature fixability and hot offset resistance.
Accordingly, the polyester component (i) and (ii) preferably have similar compositions.

When (ii) is contained, the mass ratio of (i) to (ii) is usually 5/95 to 80/20, preferably 5/95 to 30/70, more preferably 5/95 to 25/75, Particularly preferred is 7/93 to 20/80.
If the mass ratio of (i) is less than 5%, the hot offset resistance is deteriorated, and it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability.

The peak molecular weight of (ii) is usually 1000 to 10,000, preferably 2000 to 8000, and more preferably 2000 to 5000.
If it is less than 1000, the heat resistant storage stability is deteriorated, and if it exceeds 10,000, the low temperature fixability is deteriorated.

The hydroxyl value of (ii) is preferably 5 or more, more preferably 10 to 120, and particularly preferably 20 to 80.
If it is less than 5, it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability.
The acid value of (ii) is preferably 1 to 5, more preferably 2 to 4.
Since a high acid value wax is used for the wax, the binder is easy to match with the toner used for the two-component developer because the low acid value binder leads to charging and high volume resistance.

The glass transition point (Tg) of the binder resin is usually 35 to 70 ° C, preferably 55 to 65 ° C.
If it is less than 35 ° C., the heat-resistant storage stability of the toner deteriorates, which is not preferable, and if it exceeds 70 ° C., the low-temperature fixability becomes insufficient.

Since the urea-modified polyester is likely to be present on the surface of the obtained toner base particles, the toner of the present invention tends to have good heat storage stability even when the glass transition point is low, as compared with known polyester-based toners. Show.
In addition, as the colorant, charge control agent, and release agent used here, known materials are appropriately selected and used.

  Next, a toner manufacturing method will be described. Here, although a preferable manufacturing method is shown, it is not limited to this.

(Toner production method)
1) A toner material solution is prepared by dispersing a colorant, unmodified polyester, a polyester prepolymer having an isocyanate group, and a release agent in an organic solvent.

The organic solvent is preferably volatile with a boiling point of less than 100 ° C. from the viewpoint of easy removal after toner base particle formation.
Specifically, toluene, xylene, benzene, 1,2-dichloroethane, 1,1,2-trichloroethane, trichloroethylene, chloroform, methyl acetate, ethyl acetate, methyl ethyl ketone, methyl isobutyl ketone, etc. are used alone or in combination of two or more. be able to.
Particularly preferred are aromatic solvents such as toluene and xylene; halogenated hydrocarbons such as methylene chloride, 1,2-dichloroethane, chloroform and carbon tetrachloride.
The usage-amount of an organic solvent is 0-300 mass parts normally with respect to 100 mass parts of polyester prepolymers, Preferably it is 0-100 mass parts, More preferably, it is 25-70 mass parts.

2) The toner material liquid is emulsified in an aqueous medium in the presence of a surfactant and resin fine particles.
The aqueous medium may be water alone or an organic solvent such as alcohol (methanol, isopropyl alcohol, ethylene glycol, etc.), dimethylformamide, tetrahydrofuran, cellosolves (methyl cellosolve, etc.), lower ketones (acetone, methyl ethyl ketone, etc.). It may be included.

The amount of the aqueous medium used relative to 100 parts by mass of the toner material liquid is usually 50 to 2000 parts by mass, preferably 100 to 1000 parts by mass.
If the amount is less than 50 parts by mass, the dispersion state of the toner material liquid is poor, and toner particles having a predetermined particle diameter cannot be obtained. Since it is not economical when it exceeds 20000 mass parts, it is not preferable.
Further, in order to improve the dispersion in the aqueous medium, a dispersant such as a surfactant and resin fine particles is appropriately added.

  As surfactants, anionic surfactants such as alkylbenzene sulfonates, α-olefin sulfonates, phosphate esters, alkylamine salts, amino alcohol fatty acid derivatives, polyamine fatty acid derivatives, amine salt types such as imidazoline, Quaternary ammonium salt type cationic surfactants such as alkyltrimethylammonium salt, dialkyldimethylammonium salt, alkyldimethylbenzylammonium salt, pyridinium salt, alkylisoquinolinium salt, benzethonium chloride, fatty acid amide derivative, polyhydric alcohol Nonionic surfactants such as derivatives, for example, amphoteric surfactants such as alanine, dodecyldi (aminoethyl) glycine, di (octylaminoethyl) glycine and N-alkyl-N, N-dimethylammonium betaine And the like.

Further, by using a surfactant having a fluoroalkyl group, the effect can be obtained in a very small amount.
Preferred anionic surfactants having a fluoroalkyl group include fluoroalkyl carboxylic acids having 2 to 10 carbon atoms and metal salts thereof, disodium perfluorooctanesulfonyl glutamate, 3- [ω-fluoroalkyl (C6-C11 ) Oxy] -1-alkyl (C3-C4) sodium sulfonate, 3- [ω-fluoroalkanoyl (C6-C8) -N-ethylamino] -1-propanesulfonic acid sodium, fluoroalkyl (C11-C20) carvone Acids and metal salts, perfluoroalkylcarboxylic acids (C7 to C13) and metal salts thereof, perfluoroalkyl (C4 to C12) sulfonic acids and metal salts thereof, perfluorooctanesulfonic acid diethanolamide, N-propyl-N- ( 2-Hydroxyethyl) Perful Olooctanesulfonamide, perfluoroalkyl (C6-C10) sulfonamidopropyltrimethylammonium salt, perfluoroalkyl (C6-C10) -N-ethylsulfonylglycine salt, monoperfluoroalkyl (C6-C16) ethyl phosphate, etc. Can be mentioned.

  Product names include Surflon S-111, S-112, S-113 (Asahi Glass Co., Ltd.), Florard FC-93, FC-95, FC-98, FC-129 (Sumitomo 3M Co., Ltd.), Unidyne DS-101. DS-102 (manufactured by Daikin Industries, Ltd.), Megafac F-110, F-120, F-113, F-191, F-812, F-833 (manufactured by Dainippon Ink, Inc.) 103, 104, 105, 112, 123A, 123B, 306A, 501, 201, 204 (manufactured by Tochem Products), and Fgentent F-100, F150 (manufactured by Neos).

  In addition, examples of the cationic surfactant include aliphatic quaternary ammonium salts such as aliphatic primary, secondary or secondary amine acids having a fluoroalkyl group, and perfluoroalkyl (C6-C10) sulfonamidopropyltrimethylammonium salts. , Benzalkonium salt, benzethonium chloride, pyridinium salt, imidazolinium salt, trade names include Surflon S-121 (manufactured by Asahi Glass), Florard FC-135 (manufactured by Sumitomo 3M), Unidyne DS-202 (Daikin Industries) Manufactured), MegaFuck F-150, F-824 (Dainippon Ink Co., Ltd.), Xtop EF-132 (Tochem Products), Footgent F-300 (Neos), and the like.

  As the resin fine particles, any resin can be used as long as it can form an aqueous dispersion, and it may be a thermoplastic resin or a thermosetting resin.

Examples thereof include vinyl resins, polyurethane resins, epoxy resins, polyester resins, polyamide resins, polyimide resins, silicon resins, phenol resins, melamine resins, urea resins, aniline resins, ionomer resins, and polycarbonate resins.
As the resin, two or more of the above resins may be used in combination.
Among these, a vinyl resin, a polyurethane resin, an epoxy resin, a polyester resin, or a combination thereof is preferable because an aqueous dispersion of fine spherical resin particles is easily obtained.

  For example, vinyl resins are polymers obtained by homopolymerization or copolymerization of vinyl monomers, such as styrene- (meth) acrylic acid ester copolymers, styrene-butadiene copolymers, (meth) acrylic acid-acrylic acid esters. Examples thereof include resins such as a polymer, a styrene-acrylonitrile copolymer, a styrene-maleic anhydride copolymer, and a styrene- (meth) acrylic acid copolymer.

  The average particle size of the resin fine particles is 5 to 200 nm, preferably 20 to 300 nm.

  In addition, inorganic compound dispersants such as tricalcium phosphate, calcium carbonate, titanium oxide, colloidal silica, and hydroxyapatite can also be used.

As a dispersant that can be used in combination with the above resin fine particles and inorganic compound dispersant, the dispersed droplets may be stabilized by a polymer protective colloid.
For example, acrylic acid, methacrylic acid, α-cyanoacrylic acid, α-cyanomethacrylic acid, itaconic acid, crotonic acid, fumaric acid, maleic acid or maleic anhydride and other (meth) acrylic monomers containing hydroxyl groups Bodies such as acrylic acid-β-hydroxyethyl, methacrylic acid-β-hydroxyethyl, acrylic acid-β-hydroxypropyl, methacrylic acid-β-hydroxypropyl, acrylic acid-γ-hydroxypropyl, methacrylic acid-γ-hydroxy Propyl, acrylic acid-3-chloro-2-hydroxypropyl, methacrylic acid-3-chloro-2-hydroxypropyl, diethylene glycol monoacrylate, diethylene glycol monomethacrylate, glycerol monoacrylate, glycerol monomethacrylate Luric acid esters, N-methylol acrylamide, N-methylol methacrylamide, etc., vinyl alcohol or ethers with vinyl alcohol, such as vinyl methyl ether, vinyl ethyl ether, vinyl propyl ether, or compounds containing vinyl alcohol and a carboxyl group Esters such as vinyl acetate, vinyl propionate, vinyl butyrate, acrylamide, methacrylamide, diacetone acrylamide or their methylol compounds, acid chlorides such as acrylic acid chloride, methacrylic acid chloride, vinyl pyridine, vinyl pyrrolidone, vinyl Nitrogen compounds such as imidazole and ethyleneimine, or homopolymers or copolymers such as those having a heterocyclic ring thereof, polyoxyethylene, poly Xoxypropylene, polyoxyethylene alkylamine, polyoxypropylene alkylamine, polyoxyethylene alkylamide, polyoxypropylene alkylamide, polyoxyethylene nonylphenyl ether, polyoxyethylene lauryl phenyl ether, polyoxyethylene stearyl phenyl ester, polyoxy Polyoxyethylenes such as ethylene nonylphenyl ester, celluloses such as methyl cellulose, hydroxyethyl cellulose, and hydroxypropyl cellulose can be used.

The dispersion method is not particularly limited, and known equipment such as a low-speed shear method, a high-speed shear method, a friction method, a high-pressure jet method, and an ultrasonic wave can be applied.
Among these, the high-speed shearing method is preferable in order to make the particle size of the dispersion 2 to 20 μm.
When a high-speed shearing disperser is used, the rotational speed is not particularly limited, but is usually 1000 to 30000 rpm, preferably 5000 to 20000 rpm.
The dispersion time is not particularly limited, but in the case of a batch method, it is usually 0.1 to 5 minutes.
The temperature during dispersion is usually 0 to 150 ° C. (under pressure), preferably 40 to 98 ° C.

3) At the same time as the preparation of the emulsion, the amines (B) are added to cause a reaction with the polyester prepolymer (A) having an isocyanate group.

This reaction involves molecular chain crosslinking and / or elongation.
The reaction time is selected depending on the reactivity between the isocyanate group structure of the polyester prepolymer (A) and the amines (B), but is usually 10 minutes to 40 hours, preferably 2 to 24 hours.
The reaction temperature is generally 0 to 150 ° C, preferably 40 to 98 ° C.
Moreover, a well-known catalyst can be used as needed.
Specific examples include dibutyltin laurate and dioctyltin laurate.

4) After completion of the reaction, the organic solvent is removed from the emulsified dispersion (reactant), washed and dried to obtain toner base particles.

In order to remove the organic solvent, the temperature of the entire system is gradually raised in a laminar stirring state, and after giving strong stirring in a certain temperature range, the solvent base is removed to produce spindle-shaped toner base particles. .
Further, when an acid such as calcium phosphate salt or an alkali-soluble material is used as the dispersion stabilizer, the calcium phosphate salt is dissolved from the toner base particles by a method such as dissolving the calcium phosphate salt with an acid such as hydrochloric acid and washing with water. Remove.
It can also be removed by operations such as enzymatic degradation.

5) A charge control agent is injected into the toner base particles obtained above, and then inorganic fine particles such as silica fine particles and titanium oxide fine particles are externally added to obtain a toner.
The injection of the charge control agent and the external addition of the inorganic fine particles are performed by a known method using a mixer or the like.
The same inorganic fine particles as those described above can be used.
Thereby, a toner having a small particle size and a sharp particle size distribution can be easily obtained.
Furthermore, by giving strong agitation in the process of removing the organic solvent, the shape between the true spherical shape and the rugby ball shape can be controlled, and the surface morphology is also controlled between the smooth shape and the umeboshi shape. be able to.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated, this invention is not restrict | limited by an Example. All parts are parts by weight.

In the present invention, the volume ratio of the fluororesin fine particles in the protective layer is calculated as a numerical value obtained by dividing the weight part by the density. The density is a measured value based on the underwater substitution method described in JIS K-7112 “Method for measuring density and specific gravity of plastic”. The density of the outermost surface layer material excluding the fluororesin fine particles used in the present invention is 1.18 ± 0.00. 03 (g / cm ³ ). The density of PFA and PTFE used as the fluororesin fine particles was 2.15 (g / cm ³ ) as a literature value.

Example 1
A mixture having the following composition was placed in a ball mill pot and ball milled for 72 hours using φ10 mm alumina balls.

・ Titanium oxide 50 parts (CR-60: Ishihara Sangyo)
・ Alkyd resin 15 parts (Beckolite M6401-50 manufactured by Dainippon Ink & Chemicals, Inc .; solid content 50 wt%)
Melamine resin 8.3 parts (Super Becamine L-121-60 manufactured by Dainippon Ink and Chemicals, solid content: 60 wt%)
・ Methyl ethyl ketone 31.7 parts (manufactured by Kanto Chemical)

  To this milling solution, 105 parts of methyl ethyl ketone (manufactured by Kanto Chemical Co., Inc.) was added, and ball milling was further performed for 2 hours to prepare an undercoat layer coating solution. This coating solution was dip coated on an aluminum drum having a diameter of 30 mm, a length of 340 mm, and a thickness of 0.75 mm, and dried at 130 ° C. for 20 minutes to form an undercoat layer having a thickness of 3.5 μm.

  Subsequently, a mixture of 3 parts of an azo pigment (compound represented by the following chemical formula 11; manufactured by Ricoh) and 80 parts of cyclohexanone (manufactured by Kanto Kagaku) was placed in a ball mill pot and balled for 60 hours using a YTZ ball of φ5 mm. After milling, 78.4 parts of cyclohexanone was further added and ball milled for 2 hours, and then 60 parts of a polyvinyl butyral resin (hydroxyl group 33 mol%, butyral group 64 mol%) / cyclohexanone solution having a solid content concentration of 2 wt% and methyl ethyl ketone 88.9 parts were added. In addition, a charge generation layer coating solution was prepared. This coating solution was dip-coated on the undercoat layer and dried at 130 ° C. for 20 minutes to form a charge generation layer having a thickness of 0.2 μm.

  Next, a charge transport layer coating solution having the following composition was prepared, and this coating solution was dip coated on the charge generation layer and dried at 125 ° C. for 20 minutes to form a charge transport layer having a thickness of 22 μm.

Charge transport material (compound represented by the following chemical formula 12) (Ricoh) 7 parts Polycarbonate resin (TS-2050, Teijin Chemicals) 100 parts Silicone oil (KF-50, Shin-Etsu Chemical) 0.002 parts・ Tetrahydrofuran (Kanto Chemical) 77.4 parts

Further, a protective layer coating solution having the following composition is circulated on the charge transport layer in a high-speed liquid collision dispersion device (device name: Ultimateizer HJP-25005; manufactured by Sugino Machine Co., Ltd.) for 30 minutes under a pressure of 100 MPa. Spray coating [spray gun: manufactured by Peacecon PC308 Olympus, air pressure: 1.5 kgf / cm ² , drum-spray gun nozzle distance: 50 mm, nozzle opening: 3/8 rotation, spray Gun transfer speed: 7 mm / s, drum rotation speed: 120 rpm, coating frequency: 3 times], dried at 130 ° C. for 60 minutes to form a protective layer of about 5 μm, and electrophotographic photoreceptor 1 was produced.

Protective layer coating solution / perfluoroalkoxy resin particles: 5.5 parts (MPE-056, manufactured by Mitsui Fluorochemicals)
-Dispersing aid (solid content: 0.3 part): 1.0 part (Modiper F210, manufactured by NOF Corporation)
-Amine compound 2 (the above chemical formula 2; paragraph [0046]): 0.4 part-Charge transport material (the above chemical formula 12): 1 part (manufactured by Ricoh)
Polycarbonate resin: 3 parts (TS-2050, manufactured by Teijin Chemicals)
Tetrahydrofuran: 200 parts (manufactured by Kanto Chemical)
・ Cyclopentanone: 60 parts (manufactured by Nippon Zeon)

  Moreover, the amine compound 2 represented by the chemical formula 2 was prepared by the following synthesis scheme.

Example 2
An electrophotographic photoreceptor 2 was produced in the same manner as in Example 1 except that the protective layer coating solution was changed to the following composition.

Protective layer coating solution / perfluoroalkoxy resin particles: 3.3 parts (MPE-056, manufactured by Mitsui Fluorochemicals)
-Dispersing aid (solid content: 0.3 part): 1.0 part (Modiper F210, manufactured by NOF Corporation)
-Amine compound 2 (Chemical formula 2; Paragraph [0046]): 0.4 parts-Charge transport material (Chemical formula 12): 2 parts (manufactured by Ricoh)
Polycarbonate resin: 4 parts (TS-2050, manufactured by Teijin Chemicals)
Tetrahydrofuran: 200 parts (manufactured by Kanto Chemical)
・ Cyclopentanone: 60 parts (manufactured by Nippon Zeon)

Example 3
An electrophotographic photosensitive member 3 was produced in the same manner as in Example 1 except that the protective layer coating solution was changed to the following composition.

Protective layer coating solution / perfluoroalkoxy resin particles: 7.4 parts (MPE-056, manufactured by Mitsui Fluorochemicals)
-Dispersing aid (solid content: 0.3 part): 1.0 part (Modiper F210, manufactured by NOF Corporation)
-Amine compound 2 (the above chemical formula 2; paragraph [0046]): 0.4 part-Charge transport material (the above chemical formula 12): 0.6 part (manufactured by Ricoh)
Polycarbonate resin: 1.7 parts (TS-2050, manufactured by Teijin Chemicals)
Tetrahydrofuran: 200 parts (manufactured by Kanto Chemical)
・ Cyclopentanone: 60 parts (manufactured by Nippon Zeon)

Example 4
An electrophotographic photosensitive member 4 was produced in the same manner as in Example 1, except that the perfluoroalkoxy resin particles were changed to tetrafluoroethylene resin particles (made by Lubron L-2 Daikin) in Example 1.

Example 5
An electrophotographic photoreceptor 5 was produced in exactly the same manner as in Example 4, except that the amine compound was changed to the amine compound 3 represented by the chemical formula 3 (paragraph [0047]) in Example 4.

Example 6
An electrophotographic photosensitive member 6 was produced in the same manner as in Example 1, except that the amine compound was changed to the amine compound 4 represented by the chemical formula 4 (paragraph [0048]) in Example 1.

Example 7
An electrophotographic photoreceptor 7 was produced in exactly the same manner as in Example 1, except that the amine compound was changed to the amine compound 6 represented by the chemical formula 6 (paragraph [0050]) in Example 1.

Comparative Example 1
A comparative electrophotographic photosensitive member 1 was produced in the same manner as in Example 1 except that the protective layer coating solution was changed to the following composition in Example 1.

Protective layer coating solution / perfluoroalkoxy resin particles: 3.0 parts (MPE-056, manufactured by Mitsui Fluorochemicals)
-Dispersing aid (solid content: 0.3 part): 1.0 part (Modiper F210, manufactured by NOF Corporation)
-Amine compound 2 (the above chemical formula 2; paragraph [0046]): 0.4 parts-Charge transport material (the above chemical formula 12): 1.7 parts (manufactured by Ricoh)
Polycarbonate resin: 5 parts (TS-2050, manufactured by Teijin Chemicals)
Tetrahydrofuran: 200 parts (manufactured by Kanto Chemical)
・ Cyclopentanone: 60 parts (manufactured by Nippon Zeon)

Comparative Example 2
A comparative electrophotographic photoreceptor 2 was produced in the same manner as in Example 1, except that the protective layer coating solution was changed to the following composition in Example 1.

Protective layer coating solution / perfluoroalkoxy resin particles: 7.8 parts (MPE-056, manufactured by Mitsui Fluorochemicals)
-Dispersing aid (solid content: 0.3 part): 1.0 part (Modiper F210, manufactured by NOF Corporation)
・ Amine compound 2 (Chemical formula 2; Paragraph [0046]): 0.4 part Charge transport material (Chemical formula 12): 0.5 part (manufactured by Ricoh)
Polycarbonate resin: 1.4 parts (TS-2050, manufactured by Teijin Chemicals)
Tetrahydrofuran: 200 parts (manufactured by Kanto Chemical)
・ Cyclopentanone: 60 parts (manufactured by Nippon Zeon)

Comparative Example 3
Except that the amine compound 2 (amine compound represented by the chemical formula 2) was changed to the amine compound 13 (amine compound represented by the following chemical formula 13) in the protective layer coating solution of the first example, the same as in the first example. Thus, a comparative electrophotographic photosensitive member 3 was produced.

Comparative Example 4
A comparative electrophotographic photosensitive member 4 was produced in the same manner as in Example 1, except that the amine compound 2 (amine compound represented by the chemical formula 2) was removed from the protective layer coating solution of Example 1.

Comparative Example 5
A comparative electrophotographic photoreceptor 5 was produced in the same manner as in Example 1 except that the perfluoroalkoxy resin particles (MPE-056; manufactured by Mitsui Fluorochemicals) were removed from the protective layer coating solution of Example 1. .

Comparative Example 6
Except for the protective layer coating solution of Example 1, perfluoroalkoxy resin particles (MPE-056; manufactured by Mitsui Fluorochemical) and amine compound 2 (amine compound represented by the above chemical formula 2) were completely the same as Example 1. Similarly, a comparative electrophotographic photosensitive member 6 was produced.

Toner production example 1
1) Preparation of monomer composition-Styrene monomer 61.9 parts-n-butyl methacrylate 26.5 parts-Polystyrene 4.4 parts-3,5-di-tert-butylsalicylic acid zinc salt 1.8 parts-Carbon Black 5.4 parts

  The above polymerizable monomer mixture was dispersed and mixed with a ball mill for 24 hours to prepare a monomer composition.

2) 2% polyvinyl alcohol aqueous solution in a flask equipped with granulation, polymerization stirrer, thermometer, inert gas inlet tube and porous glass tube with a pore diameter of 110,000 kg, pore volume of 0.42 cc / g, 10φ × 50 mm 400 ml was taken and stirred at room temperature while feeding nitrogen gas to replace oxygen in the reaction vessel with nitrogen.

  Next, 1.56 g of azobisisobutylnitrile was added to 113 g of the monomer composition of 1) above, dissolved by stirring, passed through a porous glass tube using a pump, added into an aqueous polyvinyl alcohol solution, and after addition was completed. A mixture of polyvinyl alcohol and the monomer composition was circulated at a rate of about 120 ml / min for 2 hours using the pump and the porous glass tube, and then the internal temperature was set to 70 ° C. and polymerized for 8 hours.

  After cooling to room temperature and allowing to stand overnight, the supernatant was removed, water was added, the mixture was stirred for 1 hour, filtered, dried at 45 ° C. for 48 hours in a circulating air dryer, and sieved with a mesh opening of 75 μm to obtain a toner. It was. When the particle diameter of this toner was measured with a Coulter counter, the average particle diameter was 8.5 μm, and the particles in the range of 5 to 10 μm were 95% of the total, and the particle size distribution was extremely narrow. To 100 parts of this toner, 0.7 part of hydrophobic silica and 0.3 part of hydrophobic titanium oxide were mixed with a Henschel mixer to obtain [Toner 1].

  The suspension containing the toner particles obtained in Toner Production Example 1 is passed through an imaging unit detection zone on a flat plate, the particle image is optically detected by a CCD camera, and the perimeter of an equivalent circle having the same projected area is obtained. The average circularity, which is a value obtained by dividing by the perimeter of real particles, was evaluated. This value can be measured as an average circularity by a flow type particle image analyzer FPIA-2000. As a specific measurement method, as a dispersant in 100 to 150 ml of water from which impure solids have been removed in advance. A surfactant, preferably alkylbenzene sulfonate, is added in an amount of 0.1 to 0.5 ml, and a sample to be measured is further added in an amount of about 0.1 to 0.5 g. It is obtained by performing dispersion treatment for ˜3 minutes and measuring the shape and distribution of the toner with the above apparatus at a dispersion concentration of 3000 to 10,000 / μl. As a result of the examination so far, it has been found that a toner having 0.960 or more is effective for forming a high-definition image having a reproducibility with an appropriate density. 980 to 1.000. The circularity of the toner produced in Toner Production Example 1 was 0.98.

Evaluation Example 1
The photoreceptors of Examples 1 to 7 and Comparative Examples 1 to 6 thus prepared were mounted on a black station of a Ricoh laser printer IPSIO SP C220 (without the lubricant application means) and exposed with a laser beam having a wavelength of 655 nm. Then, [Toner 1] was loaded into the black developing unit, and the black image was evaluated.

  Further, the post-exposure potential VL at the time of laser beam overall exposure was measured using a potential measurement unit with a surface potential meter attached after removing the developing roller of the black development unit.

  The charging roller conditions are set so that the charging potential VD of the photosensitive member is close to 600 (-V), the developing bias Vb is set to 450 (-V), and the gray halftone image is printed normally. It was confirmed. The post-exposure potential VL is preferably “post-exposure potential VL−development bias Vb> 200 V”. When the post-exposure potential VL> 250 (−V), a halftone image with a low density is obtained.

  Next, after re-installing the black development unit and performing repeated printing of 30,000 sheets in A4 vertical size at room temperature and normal humidity to evaluate the image quality (afterimage, thin line blurring, etc.), charging potential VD, after exposure The potential VL was measured. Subsequently, after continuous printing of 10,000 sheets while further evaluating the image quality in an environment of 30 ° C. and 90% RH, the charged potential VD and the post-exposure potential VL were measured. In addition, the fine line scraping was evaluated from the fine line reproducibility by printing a 1-dot oblique line.

Evaluation example 2 (secondary particle diameter, covering area ratio)
About 10 arbitrary observation points on the surface of the obtained electrophotographic photoreceptors 1 to 7 and comparative electrophotographic photoreceptors 1 to 3, the surface of the sampled coating film was photographed by 4000 times with FE-SEM, and obtained. Using the image processing software (IMAGEProPlus), the coverage area ratio of the obtained SEM photograph was calculated from the number of fluororesin fine particles and the average diameter and area of each fluororesin fine particle.

Evaluation example 3 (surface friction coefficient)
For the obtained electrophotographic photosensitive members 1 to 7 and comparative electrophotographic photosensitive members 1 to 5, the Euler belt method disclosed in Japanese Patent Laid-Open No. 9-166919 is used (Type 6000 / T / The surface friction coefficient for A4 paper / 30 mm width (cut in the direction of the slit) was evaluated. The surface friction coefficient was the maximum static friction coefficient determined using the tension when the transfer paper to which a load of 100 g was applied started to move.

  Evaluation results of the above evaluation examples 1 to 3, the volume ratio of the fluororesin fine particles in the protective layer and the amount of abrasion of the protective layer of the electrophotographic photosensitive member measured by an eddy current film thickness meter MMS (manufactured by Fischer Instruments) Is shown in Table 1.

  From the evaluation results of Table 1, even when spherical toner is used, the protective layer of the electrophotographic photoreceptor contains fluororesin fine particles having a volume fraction of 20% to 60% and contains a specific amine compound. As a result, it has become possible to maintain a highly stable low surface friction coefficient. At the same time, the amount of wear was suppressed and it was confirmed that the wear resistance was improved. Further, it was confirmed that even after printing 30,000 sheets at room temperature and normal humidity, the increase in the post-exposure potential was small, and no fine line blur or afterimage was observed, and a high-quality image was stably obtained. In addition, image blurring, filming, and background stains were not generated even after the additional printing of 10,000 sheets at 30 ° C. and 90%. On the other hand, in an electrophotographic photoreceptor that does not contain fluororesin fine particles having a volume fraction of 20% or more and 60% or less in the protective layer, or an electrophotographic photoreceptor that does not contain a specific amine compound, cleaning failure or afterimage occurs. Was causing. In Comparative Example 6, since the VL was high from the beginning and thin line blurring occurred, repeated printing was not evaluated.

31 Conductive Support 33 Photosensitive Layer 35 Charge Generation Layer 37 Charge Transport Layer 39 Protective Layer

JP 2005-107471 A JP 2007-156091 A JP 2009-42564 A

Claims (9)

An electrophotographic photosensitive member having a protective layer on the surface of a photosensitive layer formed on a conductive support,
The protective layer contains fluororesin fine particles and a compound represented by the following general formula (1),
The electrophotographic photoreceptor, wherein the fluororesin fine particles are contained in the protective layer in a volume fraction of 20% to 60%.

[In the general formula (1), A and B are groups selected from the following (i) and (ii), which may be the same or different.
(I) _-CH 2 X
_(Ii) -CH 2 _CH 2 Y
However, X and Y each represent an aromatic residue that may have a substituent, a cycloalkyl group that may have a substituent, or a heterocycloalkyl group that may have a substituent. ] The electrophotographic photoreceptor according to claim 1, wherein the compound represented by the general formula (1) is an amine compound represented by the following chemical formula (2).

The electrophotographic photoreceptor according to claim 1, wherein the compound represented by the general formula (1) is an amine compound represented by the following chemical formula (3).

A charging step for charging the surface of the electrophotographic photosensitive member according to any one of claims 1 to 3,
An exposure step of forming an electrostatic latent image on the electrophotographic photoreceptor;
A developing step of developing the electrostatic latent image to form a toner image;
And a transfer step of transferring the toner image onto a recording material.   A fluororesin fine particle deformation / extension step in which the fluororesin fine particle deformation / extension member provided in contact with the surface of the electrophotographic photoconductor is rubbed to deform and extend the fluororesin fine particles exposed on the surface of the electrophotographic photoconductor. The electrophotographic method according to claim 4, comprising: The electrophotographic photosensitive member according to any one of claims 1 to 3,
Charging means for charging the electrophotographic photosensitive member;
Exposure means for forming an electrostatic latent image on the electrophotographic photoreceptor;
Developing means for developing the electrostatic latent image to form a toner image;
Transfer means for transferring the toner image onto a recording material,
The electrophotographic apparatus according to claim 1, wherein the exposure unit includes an LD or an LED that forms the electrostatic latent image. The developing unit forms one or more toner images,
The transfer means includes a primary transfer portion, an intermediate transfer member, and a secondary transfer portion,
The primary transfer unit primarily transfers the toner image developed on the electrophotographic photosensitive member onto the intermediate transfer member,
The secondary transfer unit secondarily transfers the toner image on the intermediate transfer member onto a recording material,
When the developing unit forms two or more toner images,
The primary transfer unit performs primary transfer so that the two or more toner images are laminated on the intermediate transfer member,
The electrophotographic apparatus according to claim 6, wherein the secondary transfer unit collectively transfers two or more toner images stacked on the intermediate transfer member onto the recording material. A fluororesin fine particle deformation extending member provided in contact with the electrophotographic photosensitive member;
8. The electrophotographic apparatus according to claim 6, wherein the fluororesin fine particle deformation / extension member slides and deforms and expands the fluororesin fine particles exposed on the surface of the electrophotographic photosensitive member.   An electrophotographic photosensitive member according to any one of claims 1 to 3, and at least one selected from a charging unit, an exposure unit, a developing unit, a cleaning unit, and a transfer unit, are configured integrally. A process cartridge which is detachable from a photographic apparatus main body.

Images