JP6364873B2 - Electrophotographic photosensitive member, electrophotographic photosensitive member cartridge, and image forming apparatus - Google Patents

Description

  The present invention relates to an electrophotographic photosensitive member, an electrophotographic photosensitive member cartridge, and an image forming apparatus. In particular, the present invention relates to an electrophotographic photosensitive member, an electrophotographic photosensitive member cartridge, and an image forming apparatus that are excellent in wear resistance and are particularly excellent in terms of continuous cleaning and sounding.

  The electrophotographic technique is widely used in the fields of copiers, various printers, printing presses and the like because of its excellent immediacy and high quality images. As an electrophotographic photosensitive member that is the core of the electrophotographic technology, an electrophotographic photosensitive member using an organic photoconductive material having advantages such as non-pollution, easy film formation, and easy manufacture (hereinafter simply referred to as “ Also referred to as “photoreceptor”).

  As an electrophotographic photoreceptor using an organic photoconductive material, a so-called dispersion type single-layer photoreceptor in which a photoconductive fine powder is dispersed in a binder resin, a charge generation layer and a charge transport layer are laminated. Multilayer photoreceptors are known. Multilayer photoconductors provide highly efficient charge generating materials and wide and highly safe photoconductors. Also, photoconductors can be easily formed by coating, have high productivity, and are advantageous in terms of cost. This is the mainstream of photoconductors for the reasons described above, and has been developed and put into practical use.

  On the other hand, single-layer photoconductors are slightly inferior to multilayer photoconductors in terms of electrical characteristics and have a somewhat lower degree of freedom in material selection, but can generate charges near the surface of the photoconductor. Further, since the image is not blurred even if the film is thick, there is an advantage that high printing durability can be achieved by increasing the film thickness. In addition, the single-layer type photosensitive member requires fewer coating steps, is advantageous for interference fringes and tube defects derived from a conductive substrate (support), and can use an inexpensive substrate such as a non-cutting tube. For this reason, there is an advantage that the cost can be reduced.

  An electrophotographic photosensitive member using an organic photoconductive material has the above-mentioned advantages, but does not satisfy all the characteristics required for an electrophotographic photosensitive member, and in particular, it is repeatedly used in a copying machine or a printer. However, there is a problem that the photosensitive layer gradually deteriorates. Therefore, it is desired that the damage due to repeated use is small, the sensitivity is high, the residual potential is low, and the electrical characteristics are stable. These characteristics greatly depend on the charge generation material, the charge transport material, and the binder resin. As the charge generation material, a phthalocyanine pigment or an azo pigment is mainly used because it needs to have sensitivity to a light source for light input. Various charge transport materials are known, but amine compounds are widely used because they exhibit a very low residual potential (see, for example, Patent Document 1). Also, as the binder resin used in the photosensitive layer, particularly the charge transport layer, a polycarbonate resin or a polyarylate resin is preferably used (see, for example, Patent Documents 2 and 3).

  In particular, in recent years, the outermost layer of the electrophotographic photoreceptor is required to have durability against electrical and mechanical fatigue by processes such as charging, development, transfer, and cleaning. Specifically, durability against scratches and abrasion due to rubbing and durability against chemical degradation caused by ozone, nitrogen oxides, and the like are required. Furthermore, in recent years, the demand for characteristics for cleaning residual toner has been increased with the reduction in toner particle size and the change in material, and a high level of cleaning characteristics has been demanded of the photoreceptor. Further, in order to improve the cleaning, the contact pressure with the cleaning blade also tends to increase, and in order to suppress the occurrence of blade turning and noise caused by this, it is required to improve the surface slipperiness. .

  As means for solving the electrical and mechanical durability, for example, it is disclosed that a curable resin is contained in a surface layer as a binder resin (see, for example, Patent Document 4). However, this method improves the mechanical durability of the photoreceptor surface, but tends to be weak with respect to electrical fatigue. Specifically, adhesion of ozone and nitrogen oxides to the surface layer causes image blurring, deterioration of toner consumption caused by deterioration of charging characteristics of the photoreceptor, and deterioration of blade noise due to increase of the coefficient of friction of the photoreceptor surface. There are problems such as. In order to improve such deterioration due to electrical surface degradation, it is one improvement means that the surface of the photoreceptor is appropriately ground and the surface of the photoreceptor is always kept fresh.

  In addition, it has been proposed to reduce the friction coefficient of the surface by adding a lubricant such as silicone oil to the surface layer for the sound of the blade. However, if silicone oil is simply added, most of it bleeds out to the surface, and it is difficult to hold it inside the photoreceptor. Therefore, in order to continuously improve the slipperiness of the surface, a phase separation structure is created inside the photosensitive layer, and a function of retaining oil is given to some layers to realize a sustained slipperiness. Is shown (see Patent Document 5).

JP 2006-208474 A JP 2011-002783 A JP 2011-170041 A Japanese Patent Laid-Open No. 05-053358 JP 2012-208268 A

  However, according to the study by the present inventors, in the inventions described in Patent Documents 4 and 5, abrasion resistance, cleaning resistance, filming resistance, and rubbing noise in the machine in the electrophotographic process (hereinafter referred to as the following) It was difficult to continuously satisfy all the problems of sounding. If it is possible to provide a photoreceptor that can solve all of the above problems with a simpler layer structure for forming the surface protective layer, it is advantageous in terms of productivity and cost.

  The present inventors use a charge transport layer as the outermost layer, use a resin having a specific polyarylate resin and a polysiloxane component as a binder resin of the charge transport layer, and contain silicone particles in the charge transport layer. Thus, it has been found that an electrophotographic photoreceptor can be provided that is capable of continuous cleaning and filming resistance and that can continuously suppress noise. That is, the gist of the present invention resides in the following six points.

<1> In an electrophotographic photoreceptor having an undercoat layer, a charge generation layer, and a charge transport layer on a conductive support, the charge transport layer is an outermost layer, and the outermost layer is a resin having a polysiloxane component. , Polyarylate resin, and silicone particles , wherein the silicone particles are three-dimensional
An electrophotographic photoreceptor, characterized in that it is a polysiloxane having a structure crosslinked in a network structure .
<2> The content of the silicone particles is 5 to 5 with respect to 100 parts by mass of the total binder resin.
The electrophotographic photosensitive member according to <1>, wherein the electrophotographic photosensitive member is 0 part by mass.

< 3 > The electrophotographic photosensitive member according to <1> or < 2>, wherein the polyarylate resin is a polyarylate resin having a structural unit represented by the following general formula [A].

(In the formula [A], Ar ^{3 to} Ar ⁶ each independently represent an arylene group which may have a substituent, z represents a single bond, an oxygen atom, a sulfur atom, or an alkylene group. S is 0. And represents an integer of 2 or less, and y represents a single bond, an oxygen atom, a sulfur atom, or an alkylene group.
< 4 > The electrophotographic photosensitive member according to any one of <1> to < 3 >, a charging unit for charging the electrophotographic photosensitive member, and exposing the charged electrophotographic photosensitive member to form an electrostatic latent image. An electrophotographic apparatus comprising: at least one of an exposing section for developing, a developing section for developing an electrostatic latent image formed on the electrophotographic photosensitive member, and a cleaning section for cleaning the electrophotographic photosensitive member. Photoconductor cartridge.

< 5 > The electrophotographic photosensitive member according to any one of <1> to < 3 >, a charging unit for charging the electrophotographic photosensitive member, and exposing the charged electrophotographic photosensitive member to form an electrostatic latent image. An image forming apparatus comprising: an exposure unit; and a developing unit that develops an electrostatic latent image formed on the electrophotographic photosensitive member.

  The electrophotographic photoreceptor of the present invention can continuously improve the cleaning property, filming resistance, and sound by using a charge transport layer as an outermost layer and using a specific binder resin for the charge transport layer. It is possible to provide an electrophotographic process cartridge including the electrophotographic photosensitive member and an image forming apparatus including the electrophotographic photosensitive member.

1 is a schematic diagram illustrating a main configuration of an embodiment of an image forming apparatus of the present invention.

Hereinafter, the embodiments of the present invention will be described in detail. However, the present invention is not limited to the following descriptions, and can be appropriately modified and implemented without departing from the gist of the present invention.
[Electrophotographic photoreceptor]
Hereinafter, the electrophotographic photoreceptor of the present invention will be described in detail.

≪Conductive support≫
As the conductive support used for the photoreceptor, for example, metal materials such as aluminum, aluminum alloy, stainless steel, copper, and nickel, and conductive powders such as metal, carbon, and tin oxide are added to impart conductivity. A resin material, a resin, glass, paper, or the like on which a conductive material such as aluminum, nickel, or ITO (indium tin oxide) is deposited or applied on the surface is mainly used. As a form, a drum shape, a sheet shape, a belt shape or the like is used. A conductive material having an appropriate resistance value may be applied to a conductive support of a metal material in order to control conductivity, surface properties, etc., or to cover defects.

When a metal material such as an aluminum alloy is used as the conductive support, it may be used after an anodized film is applied. When an anodized film is applied, it is desirable to perform a sealing treatment by a known method. The average film thickness of the anodized film is preferably 20 μm or less, and particularly preferably 7 μm or less.
The support surface may be smooth, or may be roughened by using a special cutting method or polishing. Further, it may be roughened by mixing particles having an appropriate particle diameter with the material constituting the support. In order to reduce the cost, it is possible to use the drawing tube as it is without cutting. In particular, when using a non-cutting aluminum substrate such as drawing, impact processing, ironing, etc., it is preferable because the treatment eliminates dirt, foreign matter, and other foreign matters, small scratches, etc., and a uniform and clean substrate can be obtained. .

<< Underlayer >>
An undercoat layer is provided between the conductive support and the photosensitive layer described later. When a conductive layer is provided on the conductive support, an undercoat layer is provided on the conductive layer. As the undercoat layer, a material in which metal oxide particles or the like are dispersed in a resin is used. These may be used alone or in combination with particles of several resins, metal oxides and the like.

  An undercoat layer may be provided between the conductive support and the photosensitive layer described later for improving adhesion and blocking properties. As the undercoat layer, a resin, a resin in which particles such as a metal oxide are dispersed, or the like is used. Examples of the metal oxide particles include metal oxide particles containing one metal element such as titanium oxide, aluminum oxide, silicon oxide, zirconium oxide, zinc oxide, iron oxide, calcium titanate, strontium titanate, titanate. Examples thereof include metal oxide particles containing a plurality of metal elements such as barium. One kind of these particles may be used alone, or a plurality of kinds of particles may be mixed and used. Among these metal oxide particles, titanium oxide and aluminum oxide are preferable, and titanium oxide is particularly preferable. The surface of the titanium oxide particles may be treated with an inorganic substance such as tin oxide, aluminum oxide, antimony oxide, zirconium oxide, or silicon oxide, or an organic substance such as stearic acid, polyol, or silicone. As the crystal form of the titanium oxide particles, any of rutile, anatase, brookite, and amorphous can be used. Moreover, the thing of a several crystal state may be contained.

In addition, various particle sizes of the metal oxide particles can be used. Among these, from the viewpoint of characteristics and liquid stability, the average primary particle size is usually 1 nm or more, preferably 10 nm or more, and usually 100 nm or less. Preferably it is 50 nm or less.
The undercoat layer is preferably formed in a form in which metal oxide particles are dispersed in a binder resin. As binder resin used for the undercoat layer, epoxy resin, polyethylene resin, polypropylene resin, acrylic resin, methacrylic resin, polyamide resin, vinyl chloride resin, vinyl chloride resin, vinyl acetate resin, phenol resin, polycarbonate resin, polyurethane resin, Polyimide resin, vinylidene chloride resin, polyvinyl acetal resin, vinyl chloride-vinyl acetate copolymer, polyvinyl alcohol resin, polyurethane resin, polyacrylic acid resin, polyacrylamide resin, polyvinyl pyrrolidone resin, polyvinyl pyridine resin, water-soluble polyarylate resin, Cellulose ester resins such as nitrocellulose, cellulose ether resins, casein, gelatin, polyglutamic acid, starch, starch acetate, amino starch, zirconium clean Compounds, organic zirconium compounds such as zirconium alkoxide compounds, titanyl chelate compounds, organic titanyl compounds such as titanyl alkoxide compound, a known binder resin such as a silane coupling agent and the like. These may be used alone or in combination of two or more in any combination and ratio. Moreover, you may use with the hardening | curing form with the hardening | curing agent. Among these, alcohol-soluble copolymerized polyamides, modified polyamides, and the like are preferable because they exhibit good dispersibility and coatability.

  The use ratio of the inorganic particles to the binder resin used in the undercoat layer can be arbitrarily selected, but is usually in the range of 10% by mass or more and 500% by mass or less from the viewpoint of the stability of the dispersion and coating properties. Is preferably used. The thickness of the undercoat layer can be selected arbitrarily, but is usually preferably in the range of 0.1 μm or more and 20 μm or less from the viewpoint of improving the photoreceptor characteristics and applicability.

≪Photosensitive layer≫
As the photosensitive layer, a stacking type photosensitive layer in which a charge generation layer and a charge transport layer are stacked in this order from the conductive support side, and conversely, a charge transport layer and a charge generation layer are stacked in this order from the conductive support side. In the present invention, a normal lamination type photosensitive layer in which the outermost layer of the photoreceptor is a charge transport layer is preferable.

≪Charge generation layer≫
The charge generation layer contains a charge generation material, and usually contains a binder resin and other components used as necessary. Such a charge generation layer is prepared by, for example, preparing a coating solution by dissolving or dispersing fine particles of a charge generation material and a binder resin in a solvent or a dispersion medium. It can be obtained by coating and drying on the top (on the undercoat layer when an undercoat layer is provided) and on the charge transport layer in the case of a reverse laminated type photosensitive layer.

<Charge generating material>
The charge generating material may be used alone or in a mixed state with several dyes and pigments. Examples of the charge generation material include inorganic photoconductive materials such as selenium and its alloys, cadmium sulfide, and organic photoconductive materials such as organic pigments. Organic photoconductive materials are preferred, and organic photoconductive materials are particularly preferable. Pigments are preferred. Examples of organic pigments include phthalocyanine pigments, azo pigments, dithioketopyrrolopyrrole pigments, squalene (squarylium) pigments, quinacridone pigments, indigo pigments, perylene pigments, polycyclic quinone pigments, anthanthrone pigments, and benzimidazole pigments. . Among these, phthalocyanine pigments or azo pigments are particularly preferred as dyes used in the mixed state from the viewpoint of photosensitivity. When organic pigments are used as the charge generating substance, usually, fine particles of these organic pigments are used in the form of a dispersion layer bound with various binder resins.

  When a phthalocyanine pigment is used as the charge generating material, specifically, metal-free phthalocyanine and metal-containing phthalocyanine are used. Specific examples of metal-containing phthalocyanines include metals such as copper, indium, gallium, tin, titanium, zinc, vanadium, silicon, germanium, or their oxides, halides, hydroxides, alkoxides, and the like. Various crystal forms of phthalocyanines are used. In particular, titanyl phthalocyanines (also known as oxytitanium phthalocyanine) such as A type (also known as β type), B type (also known as α type), D type (also known as Y type), vanadyl phthalocyanine, chloroindium phthalocyanine, which are highly sensitive crystal types Chlorogallium phthalocyanine such as type II, hydroxygallium phthalocyanine such as type V, μ-oxo-gallium phthalocyanine dimer such as type G and I, and μ-oxo-aluminum phthalocyanine dimer such as type II are suitable. is there.

  Among these phthalocyanines, A type (β type), B type (α type), D type (Y type) oxytitanium phthalocyanine, II type chlorogallium phthalocyanine, V type hydroxygallium phthalocyanine, G type μ-oxo- Gallium phthalocyanine dimer and the like are particularly preferable. In particular, oxytitanium phthalocyanine preferably has a clear diffraction peak mainly at a Bragg angle (2θ ± 0.2 °) of 27.2 ° in a powder X-ray diffraction spectrum by CuKα characteristic X-ray.

Further, the oxytitanium phthalocyanine preferably has a clear diffraction peak at a Bragg angle (2θ ± 0.2 °) of 9.0 ° to 9.7 ° in a powder X-ray diffraction spectrum by CuKα characteristic X-ray. In view of the characteristics of the electrophotographic photosensitive member, main diffraction peaks at 9.6 °, 24.1 °, 27.2 °, or 9.5 °, 9.7 °, 24.1 °, and 27.2 ° are obtained. From the viewpoint of stability at the time of dispersion, it preferably has no peak at around 26.2 °. Among the oxytitanium phthalocyanines mentioned above, 7.3 °, 9.6 °, 11.6 °, 14.2 °, 18.0 °, 24.1 ° and 27.2 °, or 7.3 °, More preferably, it has main diffraction peaks at 9.5 °, 9.7 °, 11.6 °, 14.2 °, 18.0 °, 24.2 ° and 27.2 °.

  When a metal-free phthalocyanine compound or a metal-containing phthalocyanine compound is used as the charge generation material, a highly sensitive photoreceptor can be obtained with respect to a laser beam having a relatively long wavelength, for example, a laser beam having a wavelength around 780 nm. Further, when an azo pigment such as monoazo, diazo, or trisazo is used, white light, laser light having a wavelength around 660 nm, or laser light having a relatively short wavelength (for example, a wavelength in the range of 380 nm to 500 nm). It is possible to obtain a photoreceptor having sufficient sensitivity to the laser beam).

  The phthalocyanine compound may be a single compound or several mixed or mixed crystal states. As the mixed state in the phthalocyanine compound or crystal state here, those obtained by mixing the respective constituent elements later may be used, or the mixed state in the production / treatment process of the phthalocyanine compound such as synthesis, pigmentation, crystallization, etc. It may be the one that gave rise to. As such treatment, acid paste treatment, grinding treatment, solvent treatment and the like are known. In order to generate a mixed crystal state, as described in JP-A-10-48859, two types of crystals are mixed, mechanically ground and made amorphous, and then converted into a specific crystal state by solvent treatment. The method of doing is mentioned.

  On the other hand, when an azo pigment is used as the charge generating material, various known azo pigments can be used as long as they have sensitivity to a light source for light input. Trisazo pigments are preferably used. Examples of preferred azo pigments are shown below.

  When the organic pigments exemplified above are used as the charge generation material, one kind may be used alone, or two or more kinds of pigments may be mixed and used. In this case, it is preferable to use a combination of two or more kinds of charge generating materials having spectral sensitivity characteristics in different spectral regions of the visible region and the near red region. Among them, a disazo pigment, a trisazo pigment and a phthalocyanine pigment are preferably used in combination. More preferred.

<Binder resin for charge generation layer>
Examples of binder resins used in the charge generation layer include polyvinyl butyral resins, polyvinyl formal resins, polyvinyl acetal resins such as partially acetalized polyvinyl butyral resins in which a part of butyral is modified with formal, acetal, or the like, polyarylate Resin, polycarbonate resin, polyarylate resin, modified ether-based polyarylate resin, phenoxy resin, polyvinyl chloride resin, polyvinylidene chloride resin, polyvinyl acetate resin, polystyrene resin, acrylic resin, methacrylic resin, polyacrylamide resin, polyamide resin, Polyvinylpyridine resin, cellulosic resin, polyurethane resin, epoxy resin, silicone resin, polyvinyl alcohol resin, polyvinylpyrrolidone resin, casein, vinyl chloride-vinyl acetate Copolymer, hydroxy-modified vinyl chloride-vinyl acetate copolymer, carboxyl-modified vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate-maleic anhydride copolymer, etc. , Styrene-butadiene copolymer, vinylidene chloride-acrylonitrile copolymer, styrene-alkyd resin, silicon-alkyd resin, phenol-formaldehyde resin and other insulating resins, poly-N-vinylcarbazole, polyvinylanthracene, polyvinylperylene, etc. These organic photoconductive polymers can be selected and used, but are not limited to these polymers. These binder resins may be used alone or in combination of two or more.

  In the charge generation layer, the blending ratio (mass) of the binder resin and the charge generation material is in the range of 10 to 1000 parts by weight, preferably 30 to 500 parts by weight with respect to 100 parts by weight of the binder resin. If the ratio is too high, the stability of the coating solution may be reduced due to aggregation of the charge generation material. On the other hand, if the ratio of the charge generating substance is too low, the sensitivity as a photoreceptor may be reduced.

  Specifically, the charge generation layer is prepared by dispersing the above-mentioned binder resin in an organic solvent and dispersing a charge generation material to prepare a coating solution, which is then applied on a conductive support (if an undercoat layer is provided, an undercoat layer). It is formed by coating. As a method for dispersing the charge generation material, a known dispersion method such as a ball mill dispersion method, an attritor dispersion method, or a sand mill dispersion method can be used. In this case, it is effective to refine the particles to a particle size of 0.5 μm or less, preferably 0.3 μm or less, more preferably 0.15 μm or less. The film thickness is usually 0.1 μm to 10 μm, preferably 0.15 μm to 0.6 μm.

≪Charge transport layer≫
The charge transport layer is the outermost layer and contains a resin having a polysiloxane component, a polyarylate resin, and silicone particles. The polyarylate resin is preferably used as a binder resin in order to ensure film strength. In the case of a charge transport layer, it can be obtained by applying and drying a coating solution obtained by dissolving or dispersing a charge transport material and various binder resins in a solvent.

<Resin having a polysiloxane component>
The resin having a polysiloxane component used in the present invention may be any resin as long as the resin has a polysiloxane component as a partial structure. Examples of the resin component constituting the resin having a polysiloxane component include vinyl compounds such as butadiene resin, styrene resin, vinyl acetate resin, vinyl chloride resin, acrylate ester resin, methacrylate ester resin, vinyl alcohol resin, and ethyl vinyl ether. Polymers and copolymers, polyvinyl butyral resin, polyvinyl formal resin, partially modified polyvinyl acetal, polycarbonate resin, polyarylate resin, polyarylate resin, polyamide resin, polyurethane resin, cellulose ester resin, phenoxy resin, silicone resin, silicone Alkyd resins, poly-N-vinylcarbazole resins, and resins obtained by copolymerizing a plurality of these resins are used. Among these, polycarbonate resin and polyarylate resin are preferable from the viewpoint of mechanical strength.

As the configuration of the resin having a polysiloxane component, the configuration of a resin having a known polysiloxane can be used. For example, when the resin component is A and the polysiloxane component is B, the following configuration is exemplified.
1. A block copolymer having a polysiloxane component at one end as in AB
2. A block copolymer having polysiloxane components at both ends as in B-A-B
3. A block copolymer having a resin component on both sides of a polysiloxane component, such as ABA
4). A block copolymer in which the polysiloxane component is branched from the main chain resin, such as AA (-B) -A
Furthermore, it is possible to use a resin in which one of these or a plurality of configurations is combined. Among these, from the viewpoint of reducing the surface free energy of the photoreceptor, a resin having a polysiloxane component at least at one end, that is, a resin having a polysiloxane component at one end (Example 1 above), or both ends It is preferable to use a resin having a polysiloxane component (Example 2 above).

<Polycarbonate resin or polyarylate resin having a polysiloxane structure in at least a part of the polymer terminal and the repeating structure>
[1-1. Polycarbonate resin and polyarylate resin having polysiloxane structure at least at part of polymer terminal]
(1-1-1. Bisphenol component and polymer terminal structure)
The polycarbonate resin and polyarylate resin having a polysiloxane structure at the polymer terminal contained in the outermost layer of the electrophotographic photosensitive member of the present invention have a bisphenol component represented by the following general formula (1), and the polymer It will not specifically limit if it is a polycarbonate resin and polyarylate resin which have a structure represented by following General formula (2) in at least one part of a terminal.

In general formula (1), R ^{1 to} R ⁸ are each independently hydrogen, an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 3 to 10 carbon atoms, a halogen, a halogenated alkyl group, an alkoxy group, or a nitro group. Or the aryl group which may have a substituent is represented.
X is

A single bond, lactone, or fluorene is shown, and R ^{9 to} R ¹⁵ may each independently have a hydrogen atom, an alkyl group having 1 to 10 carbon atoms that may have a substituent, or a substituent. A good alkenyl group having 3 to 10 carbon atoms, a halogen, an alkoxyl group, and an aryl group having 6 to 20 carbon atoms which may have a substituent, and Z is a bond carbon and 3 to 20 carbon atoms. Represents a substituted or unsubstituted cycloalkylidene group, a represents an integer of 0 or more and 4 or less, l represents an integer of 1 or more and 6 or less, and m represents an integer of 2 or more and 20 or less.

It is more preferable that R ⁹ and R ¹⁰ are each independently an alkyl group having 2 or less carbon atoms, and it is particularly preferable that R ⁹ is a hydrogen atom and R ¹⁰ is a methyl group.

In the general formula (2), W represents a single bond, O, CO, COO, NH, NHCO, S, SO, SO ₂ , and Y represents a divalent organic containing at least one of aliphatic and aromatic. R ^{16 to} R ¹⁸ are siloxane groups, at least one of which is represented by the following general formula (3), the rest being an alkyl group having 1 to 10 carbon atoms, and an alkenyl group having 3 to 10 carbon atoms. , A halogen, a halogenated alkyl group, an alkoxyl group, and an aryl group which may have a substituent.

In General Formula (3), R ^{19 to} R ²¹ represent an alkyl group or an aryl group, and n represents an integer of 1 to 500.
Although the polysiloxane structure which the polycarbonate resin and polyarylate resin used for this invention have at least one part of a polymer terminal is shown below, arbitrary things can be used unless the effect of this invention is impaired remarkably.

(1-1-2. Dicarboxylic acid component of polyarylate resin)
The dicarboxylic acid component which is a dicarboxylic acid residue in the polyarylate resin contained in the present invention is represented by the following general formula (4).

In General Formula (4), Ar ¹ and Ar ² each independently represent an arylene group which may have a substituent, and X ² represents a single bond, an oxygen atom, a sulfur atom, or the following General Formula (5). Or a group represented by the following general formula (6), wherein k represents an integer of 0 or more.

R ²² and R ²³ in the general formula (5) each independently represent a hydrogen atom, an alkyl group, or an aryl group, and R ²² and R ²³ may be bonded to form a ring.
—O—R ²⁴ —O— Formula (6)
R ²⁴ in the general formula (6) is an alkylene group, an arylene group, or a group represented by the following general formula (7).

—R ²⁵ —Ar ³ —R ²⁶ — General formula (7)
R ²⁵ and R ²⁶ in the general formula (7) each independently represent an alkylene group, and Ar ³ represents an arylene group.
Examples of the dicarboxylic acid residue contained in the general formula (4) include structures represented by the following general formulas [I] to [VI]. Here, k is an integer of 0 or more, but an integer of 0 to 5 is preferable from the viewpoint of electrical characteristics and scratch resistance, and more preferably 0 or 1.

From the viewpoint of film resistance, k is preferably 1 and X ² is an oxygen atom, the following general formula (8)
It is represented by

Ar ¹² and Ar ¹³ in the general formula (8) are as described above, and preferably a phenylene group having no substituent.
Specific examples of the preferred dicarboxylic acid residue represented by the general formula (8) include diphenyl ether-2,2′-dicarboxylic acid residue, diphenyl ether-2,3′-dicarboxylic acid residue, diphenyl ether-2,4 ′. -Dicarboxylic acid residue, diphenyl ether-3,3'-dicarboxylic acid residue, diphenyl ether-3,4'-dicarboxylic acid residue, diphenyl ether-4,4'-dicarboxylic acid residue and the like. Among these, considering the simplicity of production of the dicarboxylic acid component, diphenyl ether-2,2′-dicarboxylic acid residue, diphenyl ether-2,4′-dicarboxylic acid residue, diphenyl ether-4,4′-dicarboxylic acid Residues are more preferred, and diphenyl ether-4,4′-dicarboxylic acid residues are particularly preferred.

Specific examples of the dicarboxylic acid residues other than those represented by the general formula (8) include phthalic acid residues, isophthalic acid residues, terephthalic acid residues, toluene-2,5-dicarboxylic acid residues, p Xylene-2,5-dicarboxylic acid residue, naphthalene-1,4-dicarboxylic acid residue, naphthalene-2,3-dicarboxylic acid residue, naphthalene-2,6-dicarboxylic acid residue, biphenyl-2,2 '-Dicarboxylic acid residue, biphenyl-4,4'-dicarboxylic acid residue can be mentioned, preferably phthalic acid residue, isophthalic acid residue, terephthalic acid residue, naphthalene-1,4-dicarboxylic acid residue Naphthalene-2,6-dicarboxylic acid residue, biphenyl-2,2′-dicarboxylic acid residue, biphenyl-4,4′-dicarboxylic acid residue, particularly preferably isophthalic acid residue, terephthalic acid residue. Base It is also possible to use a combination of a plurality of these dicarboxylic acid residues.

  The polyarylate resin may be a resin containing another dicarboxylic acid component and enclosing the general formula (4) in a part of the structure. Specific examples of other dicarboxylic acid residues include adipic acid residues, suberic acid residues, sebacic acid residues, pyridine-2,3-dicarboxylic acid residues, pyridine-2,4-dicarboxylic acid residues, pyridine -2,5-dicarboxylic acid residue, pyridine-2,6-dicarboxylic acid residue, pyridine-3,4-dicarboxylic acid residue, pyridine-3,5-dicarboxylic acid residue, preferably, These are adipic acid residues and sebacic acid residues, and a plurality of these dicarboxylic acid residues can be used in combination.

  In addition, when it has the dicarboxylic acid residue represented by General formula (4) and the other dicarboxylic acid residue mentioned above, the dicarboxylic acid residue represented by General formula (4) is 70 as the number of repeating units. % Or more is preferable, 80% or more is more preferable, and 90% or more is particularly preferable. Most preferably, when having only the dicarboxylic acid residue represented by the general formula (4), that is, the dicarboxylic acid residue (4) represented by the general formula (4) is 100% as the number of repeating units. This is the case.

  Moreover, when it has the dicarboxylic acid residue represented by General formula (8) and the other dicarboxylic acid residue mentioned above, the dicarboxylic acid residue represented by General formula (8) is usually as the number of repeating units. From the viewpoint of film resistance, it is preferably 70% or more, more preferably 80% or more, and particularly preferably 90% or more. Most preferably, it has only the dicarboxylic acid residue represented by the general formula (8), that is, the dicarboxylic acid residue represented by the general formula (8) is 100% as the number of repeating units. is there.

[1-2. Polycarbonate resin or polyarylate resin having a polysiloxane structure in at least a part of the repeating structural unit]
(1-2-1. Bisphenol component having a polysiloxane structure)
The polycarbonate resin and polyarylate resin having a polysiloxane structure in the repeating structural unit of the diol component contained in the outermost layer of the electrophotographic photoreceptor of the present invention are represented by the following general formula (9) or the following general formula (10). If it is the polycarbonate resin and polyarylate resin which have the diol component made, it will not specifically limit.

In general formula (9), R < ²⁷ > -R < ³⁰ > respectively independently represents the alkyl group which may have a substituent, the aryl group which may have a substituent, or the said General formula (3). , P and q each independently represents an integer of 0 to 500.

In general formula (10), R ^{31 to} R ³⁷ each independently represents an alkyl group or an aryl group which may have a substituent, and R ^* represents an alkyl group which may have a substituent, The aryl group which may have a substituent or the said General formula (2) is represented. f to j each independently represents an integer of 0 to 500. In the present invention, the proportion (mol%) of the amount of the bisphenol component represented by the general formula (10) contained in one molecule of polycarbonate or polyarylate is not particularly limited as long as the effect of the present invention is not significantly affected. Although the upper limit is usually 30 mol% or less, preferably 20 mol% or less, more preferably 10 mol% or less, particularly preferably 5 mol% or less, while the lower limit is usually 0.001 mol% or more. Preferably, it is 0.01 mol% or more, More preferably, it is 0.05 mol% or more. Further, the mass ratio (wt%) of the bisphenol component represented by the general formula (10) contained in one molecule of polycarbonate or polyarylate is not particularly limited as long as it does not significantly affect the effect of the present invention, The upper limit is usually 30 wt% or less, preferably 20 wt% or less, more preferably 10 wt% or less, while the lower limit is usually 0.01 wt% or more, preferably 0.05 wt% or more. And more preferably 0.1 wt%.

(1-2-2. Other ingredients)
Another bisphenol component contained as a copolymerization component separately from the bisphenol component (1-2-1.) Is a bisphenol represented by the general formula (1) described in (1-1-1.). The components are preferably used as well.
Further, the polycarbonate resin or polyarylate resin having a polysiloxane structure in the repeating structural unit contained in the present invention may have a polysiloxane structure at the polymer terminal, and the structure is the above (1-1). -1)) is represented in the same manner as the general formula (2).

In addition, as the dicarboxylic acid component of the polyarylate resin having a polysiloxane structure in the repeating structural unit contained in the present invention, the dicarboxylic acid component described in (1-1-2.) Is preferably used.
Among polycarbonate resins and polyarylate resins having a polysiloxane structure in at least a part of the polymer ends and repeating structures mentioned in [1-1] and [1-2], cleaning properties and filming resistance From the viewpoint, those represented by the following general formula (11) are particularly preferred, and those represented by the following general formula (12) are most preferred.

In the above formula (11) and (12), ^{X 1} is the same as X described above ^{(1-1-1), R 1 R 1} ~R 10 is described above (1-1-1) is the same as that of the ~R ^10.
[1-3. Content of polycarbonate resin or polyarylate resin having polysiloxane structure in at least part of polymer terminal and repeating structure]
In the present invention, from the viewpoint of obtaining sufficient surface slipperiness of the photoreceptor surface, the content of the polycarbonate resin or polyarylate resin having a polysiloxane structure at the polymer terminal is 100 parts by mass of the binder resin contained in the photosensitive layer. On the other hand, the upper limit is usually 100 parts by mass or less, preferably 50 parts by mass or less, more preferably 25 parts or less, while the lower limit is usually 2 parts by mass or more, preferably 4 parts by mass. As mentioned above, More preferably, it is 10 mass parts or more. It depends on the content of polysiloxane contained in the polycarbonate resin or polyarylate resin having a polysiloxane structure at the polymer terminal shown below.

[1-4. Ratio of polysiloxane structure in polycarbonate resin or polyarylate resin having polysiloxane structure in at least part of polymer terminal and repeating structure]
The upper limit of the proportion of the polysiloxane structure contained in the polycarbonate resin or polyarylate resin having a polysiloxane structure in at least a part of the polymer terminal and the repeating structure is usually 10% by mass or less, preferably 7% by mass. On the other hand, the lower limit is usually 2% by mass or more, preferably 4% by mass or more.

  The viscosity-average molecular weight of the resin having a polysiloxane component is arbitrary as long as the effects of the present invention are not significantly impaired. From the viewpoint of wear resistance, it is preferably 20,000 or more, more preferably 30,000 or more, The upper limit is preferably 100,000 or less, more preferably 90,000 or less, from the viewpoints of solubility in a solvent and productivity. If the value of the viscosity average molecular weight is too small, the mechanical strength of the polyarylate resin may be insufficient, and if it is too large, the viscosity of the coating solution for forming the photosensitive layer may be too high and the productivity may decrease. There is. In addition, a viscosity average molecular weight can be measured by the method as described in an Example using an Ubbelohde type capillary viscometer etc., for example.

  The compounding ratio (mass) of the resin having the polysiloxane component and the other binder resin in the total binder resin in the charge transport layer is usually 5 parts by mass of the resin having the polysiloxane component with respect to 100 parts by mass of the total binder resin. As mentioned above, from the viewpoint of surface slipperiness, it is preferably 20 parts by mass or more. From the viewpoint of wear resistance and surface mechanical properties, it is usually 90 parts by mass or less, preferably 50 parts by mass or less.

<Polyarylate resin>
The polyarylate resin preferably includes, for example, a repeating structure represented by the following general formula [A], and can be produced by, for example, a divalent hydroxyaryl component and a dicarboxylic acid component by a known method.

In the formula [A], Ar ^{3 to} Ar ⁶ each independently represent an arylene group which may have a substituent, and z represents a single bond, an oxygen atom, a sulfur atom, or an alkylene group. s represents an integer of 0 or more and 2 or less. y represents a single bond, an oxygen atom, a sulfur atom, or an alkylene group. In the above formula [A], Ar ^{3 to} Ar ⁶ each independently represent an arylene group that may have a substituent. As carbon number which an arylene group has, it is 6 or more normally, and the upper limit is 20 or less normally, Preferably it is 10 or less, More preferably, it is 6. If the number of carbon atoms is too large, the production cost increases and the electrical characteristics may deteriorate.

Specific examples of Ar ^{3 to} Ar ⁶ include 1,2-phenylene group, 1,3-phenylene group, 1,4-phenylene group, naphthylene group, anthrylene group, phenanthrylene group, and the like. Among these, the arylene group is preferably a 1,4-phenylene group from the viewpoint of electrical characteristics. An arylene group may be used individually by 1 type, and may be used 2 or more types by arbitrary ratios and combinations.

Moreover, examples of the substituent for Ar ^{3 to} Ar ⁶ include an alkyl group, an aryl group, a halogen group, and an alkoxy group. Among them, considering the mechanical properties as a binder resin for the photosensitive layer and the solubility in the coating solution for forming the photosensitive layer, the alkyl group is preferably a methyl group, an ethyl group, a propyl group, or an isopropyl group, and is preferably an aryl group. Is preferably a phenyl group or a naphthyl group, a halogen group is preferably a fluorine atom, a chlorine atom, a bromine atom or an iodine atom, and an alkoxy group is preferably a methoxy group, an ethoxy group, a propoxy group or a butoxy group. In addition, when a substituent is an alkyl group, carbon number of the alkyl group is usually 1 or more, and usually 10 or less, preferably 8 or less, more preferably 2 or less.

More specifically, Ar ⁵ and Ar ⁶ each independently preferably has a substituent number of 0 or more and 2 or less, more preferably has a substituent from the viewpoint of adhesion, and among these, substitution from the viewpoint of wear resistance. It is particularly preferable that the number of groups is one. Moreover, as a substituent, an alkyl group is preferable and a methyl group is particularly preferable.
On the other hand, Ar ³ and Ar ⁴ each independently preferably have 0 or more and 2 or less substituents, and more preferably have no substituents from the viewpoint of wear resistance.

In the above formula [A], y is a single bond, an oxygen atom, a sulfur atom, or an alkylene group. As the alkylene group, —CH ₂ —, —CH (CH ₃ ) —, —C (CH ₃ ) ₂ —, and cyclohexylene are preferable, and —CH ₂ —, —CH (CH ₃ ) —, — are more preferable. C (CH ₃ ) ₂ — and cyclohexylene are preferable, and —CH ₂ — and —CH (CH ₃ ) — are particularly preferable.

In the formula [A], z is a single bond, an oxygen atom, a sulfur atom, or an alkylene group, and among them, z is preferably an oxygen atom. In this case, s is preferably 0 or 1, and most preferably 1.
Specific examples of the preferred dicarboxylic acid residue when s is 1 include diphenyl ether-2
, 2'-dicarboxylic acid residue, diphenyl ether-2,3'-dicarboxylic acid residue, diphenyl ether-2,4'-dicarboxylic acid residue, diphenyl ether-3,3'-dicarboxylic acid residue, diphenyl ether-3,4 Examples include a '-dicarboxylic acid residue, diphenyl ether-4,4'-dicarboxylic acid residue, and the like. Among these, considering the simplicity of production of the dicarboxylic acid component, diphenyl ether-2,2′-dicarboxylic acid residue, diphenyl ether-2,4′-dicarboxylic acid residue, diphenyl ether-4,4′-dicarboxylic acid Residues are more preferred, and diphenyl ether-4,4′-dicarboxylic acid residues are particularly preferred.

Specific examples of the dicarboxylic acid residue when s is 0 include phthalic acid residue, isophthalic acid residue, terephthalic acid residue, toluene-2,5-dicarboxylic acid residue, p-xylene-2,5- Dicarboxylic acid residue, naphthalene-1,4-dicarboxylic acid residue, naphthalene-2,3-dicarboxylic acid residue, naphthalene-2,6-dicarboxylic acid residue, biphenyl-2,2′-dicarboxylic acid residue, Biphenyl-4,4′-dicarboxylic acid residue may be mentioned, preferably phthalic acid residue, isophthalic acid residue, terephthalic acid residue, naphthalene-1,4-dicarboxylic acid residue, naphthalene-2,6- Dicarboxylic acid residues, biphenyl-2,2′-dicarboxylic acid residues, biphenyl-4,4′-dicarboxylic acid residues, particularly preferably isophthalic acid residues and terephthalic acid residues. It is also possible to use a combination of a plurality of rubonic acid residues. Preferable specific examples include polyarylate resins having structural units represented by the following formulas (13) and (14). In formulas (13) and (14), the ratio of the isophthalic acid residue to the terephthalic acid residue is usually 50:50, but can be arbitrarily changed. In that case, the higher the ratio of terephthalic acid residues, the better from the viewpoint of electrical characteristics.

  The viscosity average molecular weight of the polyarylate resin is preferably 30,000 or more, more preferably 50,000 or more, from the viewpoint of wear resistance and surface mechanical properties, and the upper limit thereof is solubility in a solvent, and From the viewpoint of productivity, it is preferably 100,000 or less, more preferably 90,000 or less. In addition, a viscosity average molecular weight can be measured by the method as described in an Example using an Ubbelohde type capillary viscometer etc., for example.

  The compounding ratio (mass) of the polyarylate resin and other binder resin in the total binder resin in the charge transport layer is such that the polyarylate resin is usually 10 parts by mass or more with respect to 100 parts by mass of the total binder resin, wear resistance, And from a viewpoint of surface mechanical properties, Preferably it is 50 mass parts or more. The lower limit is usually 95 parts by mass or less, and preferably 80 parts by mass or less from the viewpoint of surface slipperiness.

<Silicone particles>
Silicone particles used in the present invention include spherical powders obtained by coating the surface of a spherical silicone rubber powder with a silicone resin, such as KMP-600, KMP-601, KMP-602, KMP-605, X-52-7030 (Shin-Etsu Chemical Co., Ltd.). And a polyorganosilsesquioxane cured powder having a structure in which a siloxane bond is cross-linked in a three-dimensional network represented by (RSiO _3/2 ) n, such as KMP-590. , KMP-701, X-52-854, X-52-1621 (manufactured by Shin-Etsu Chemical Co., Ltd., trade name) and the like. Among these, the entire particle is made of a silicone resin crosslinked in a three-dimensional network structure, for example, a polysiloxane having a structure in which the siloxane bond is crosslinked in a three-dimensional network represented by (RSiO _3/2 ) n. The organosilsesquioxane cured product is particularly preferable from the viewpoint that it does not expand or dissolve in many organic solvents.

Moreover, in this invention, it is preferable that the average particle diameter of the silicone rubber particle or the silicone rubber particle which coat | covered the surface with the silicone resin is 10 micrometers or less. This is because if the thickness exceeds 10 μm, the unevenness of the surface of the photoreceptor becomes too large, which may cause the cleaning property to deteriorate.
The blending ratio (mass) of the total binder resin and silicone particles in the charge transport layer is usually 5 parts by mass or more for silicone particles with respect to 100 parts by mass of the binder resin, preferably 20 masses from the viewpoint of maintaining surface slipperiness. Or more. From the viewpoint of maintaining the properties of the binder resin, it is usually 100 parts by mass or less, preferably 50 parts by mass or less.

  The content of the resin having a polysiloxane component, the polyarylate resin, and the silicone particles is such that the resin having the polysiloxane component is added to the resin having the polysiloxane component with respect to 100 parts by mass of the polyarylate resin, and the viewpoint of improving the dispersibility of the silicone particles. From the viewpoint of usually 10 parts by mass or more, preferably 20 parts by mass or more, ensuring abrasion resistance and improving surface mechanical properties, usually 100 parts by mass or less, preferably 40 parts by mass or less. From the viewpoint of sustaining, it is usually 5 parts by mass or more, preferably 20 parts by mass or more, and from the viewpoint of maintaining the properties of the binder resin, it is usually 100 parts by mass or less.

  When a resin having a polysiloxane component is used as a binder resin as in the present invention, when silicone particles described later are dispersed in the coating solution for the photosensitive layer, the affinity with the binder resin is increased and the dispersibility is improved. The effect can be expected. Further, the good dispersion state is reflected in the dried coating film, and a photosensitive layer in which silicone particles are uniformly dispersed can be formed. That is, in the present invention, the use of a resin having a polysiloxane component as a binder resin for the charge transport layer improves the slipperiness of the surface of the photoreceptor, reduces friction with the cleaning blade, and disperses silicone particles. It also has the role of an agent.

<Other binder resins>
Other binder resins that may be used include, for example, polymers of vinyl compounds such as butadiene resins, styrene resins, vinyl acetate resins, vinyl chloride resins, acrylic ester resins, methacrylic ester resins, vinyl alcohol resins, ethyl vinyl ethers, and the like. Copolymer, polyvinyl butyral resin, polyvinyl formal resin, partially modified polyvinyl acetal, polycarbonate resin, polyarylate resin, polyarylate resin, polyamide resin, polyurethane resin, cellulose ester resin, phenoxy resin, silicone resin, silicon-alkyd resin, poly -N-vinylcarbazole resin and the like. These resins may be modified with a silicon reagent or the like. Of the binder resins, polycarbonate resins and polyarylate resins are particularly preferable. These can also be used by crosslinking with an appropriate curing agent by heat, light or the like. Two or more kinds of binder resins can be blended and used.

<Charge transport material>
The charge transport material is not particularly limited, and any material can be used. Examples of known charge transport materials include aromatic nitro compounds such as 2,4,7-trinitrofluorenone, cyano compounds such as tetracyanoquinodimethane, electron withdrawing materials such as quinone compounds such as diphenoquinone, and carbazole derivatives. , Indole derivatives, imidazole derivatives, oxazole derivatives, pyrazole derivatives, thiadiazole derivatives, heterocyclic compounds such as benzofuran derivatives, aniline derivatives, hydrazone derivatives, aromatic amine derivatives, stilbene derivatives, butadiene derivatives, enamine derivatives, and a plurality of these compounds Examples thereof include an electron-donating substance such as a polymer in which a species is bonded or a polymer having a group composed of these compounds in the main chain or side chain. Among these, carbazole derivatives, aromatic amine derivatives, stilbene derivatives, butadiene derivatives, enamine derivatives, and those in which a plurality of these compounds are bonded are preferable. Any one of these charge transport materials may be used alone, or two or more thereof may be used in any combination. The ratio of the charge transport material is usually 10% by mass or more with respect to the binder resin, and preferably 30% by mass or more from the viewpoint of the light attenuation characteristics of the electrophotographic photosensitive member, and the high-speed response of the electrophotographic photosensitive member. In view of the above, it is more preferably 40% by mass or more, and particularly preferably 50% by mass or more. From the viewpoint of printing durability, it is preferably 130% by mass or less, more preferably 100% by mass or less, and particularly preferably 80% by mass or less.

  Preferred specific examples of the charge transport material are shown below. In the following compounds, R may be the same or different. Specifically, a hydrogen atom, an alkyl group, an alkoxy group, a phenyl group, an arylalkyl and the like are preferable. Particularly preferred is a methyl group, an ethyl group or a benzyl group. N is an integer of 0 or more and 2 or less. The following examples are specific examples of the charge transport material, and other charge transport materials are not limited to the following.

<Method for forming each layer>
Each layer constituting the above-described photoreceptor is formed by dip coating, spray coating, nozzle coating, bar coating, roll coating, blade coating on a conductive support obtained by dissolving or dispersing a substance to be contained in a solvent. It is formed by repeating a coating / drying step sequentially for each layer by a known method such as coating.

There are no particular restrictions on the solvent or dispersion medium used in the preparation of the coating solution, but specific examples include alcohols such as methanol, ethanol, propanol and 2-methoxyethanol, tetrahydrofuran, 1,4-dioxane, dimethoxyethane and the like. Ethers, esters such as methyl formate and ethyl acetate, acetone, methyl ethyl ketone, cyclohexanone, ketones such as 4-methoxy-4-methyl-2-pentanone, aromatic hydrocarbons such as benzene, toluene, xylene, dichloromethane, Chlorinated hydrocarbons such as chloroform, 1,2-dichloroethane, 1,1,2-trichloroethane, 1,1,1-trichloroethane, tetrachloroethane, 1,2-dichloropropane, trichloroethylene, n-butylamine, isopropanolamine, Diethyla Emissions, triethanolamine, ethylenediamine, nitrogen-containing compounds such as triethylenediamine, acetonitrile, N- methylpyrrolidone, N, N- dimethylformamide, aprotic polar solvents such as dimethyl sulfoxide and the like. Moreover, these may be used individually by 1 type and may use 2 or more types together by arbitrary combinations and kinds.

The amount of the solvent or dispersion medium used is not particularly limited, but considering the purpose of each layer and the properties of the selected solvent / dispersion medium, it is appropriate so that the physical properties such as solid content concentration and viscosity of the coating liquid are within a desired range. It is preferable to adjust.
For example, in the case of a charge transport layer, the solid content concentration of the coating solution is usually 5% by mass or more, preferably 10% by mass or more, and usually 40% by mass or less, preferably 35% by mass or less. In addition, the viscosity of the coating solution is usually 10 mPa · s or higher, preferably 50 mPa · s or higher, and usually 500 mPa · s or lower, preferably 400 mPa · s or lower, at the temperature during use. In the case of the charge generation layer, the solid content concentration of the coating solution is usually 0.1% by mass or more, preferably 1% by mass or more, and usually 15% by mass or less, preferably 10% by mass or less. In addition, the viscosity of the coating solution is usually 0.01 mPa · s or higher, preferably 0.1 mPa · s or higher, and usually 20 mPa · s or lower, preferably 10 mPa · s or lower, at the temperature during use.

  Each layer constituting these photoconductors is formed by applying the coating solution obtained by the above-described method on a support using a known coating method, repeating the coating and drying steps for each layer, and sequentially coating the layers. The Examples of the coating method include a dip coating method, a spray coating method, a spinner coating method, a bead coating method, a wire bar coating method, a blade coating method, a roller coating method, an air knife coating method, and a curtain coating method. Other known coating methods can also be used.

The coating solution is preferably dried by touching at room temperature, followed by heating or drying in a temperature range of usually 30 ° C. or more and 200 ° C. or less for 1 minute to 2 hours, while still or blowing. Further, the heating temperature may be constant, or heating may be performed while changing the temperature during drying.
<Toner>
When an image is formed using the electrophotographic photosensitive member of the present invention, a toner as a developer is used to develop a latent image. By using the toner as described above, the image forming apparatus of the present invention can form a high-quality image.

<Toner circularity>
The shape of the toner is such that the shape of each particle contained in the particle group constituting the toner is closer to each other, and the closer to a sphere, the less the localization of the charge amount in the toner particles and the more developability. It tends to be uniform, which is preferable for improving image quality. In particular, if the toner has a shape close to a perfect sphere, the contact area with the electrophotographic photosensitive member may be reduced, the toner transfer rate may be increased, and the toner consumption may be reduced. . On the other hand, it is difficult to manufacture a perfect spherical toner, and the cost of the toner increases. Therefore, it is sufficient that the toner is close to a sphere under a certain condition, and it is not necessary to be a perfect sphere.

  Therefore, specifically, the toner has an average circularity measured by a flow type particle image analyzer of usually 0.940 or more, preferably 0.945 or more, more preferably 0.950 or more, and still more preferably 0. .955 or more, particularly preferably 0.960 or more. The upper limit of the average circularity is not limited as long as it is 1.000 or less, but is preferably 0.998 or less, more preferably 0.995 or less from the viewpoint of ease of production.

<Toner type>
The toner is not limited as long as it has the above average circularity. Various types of toner are usually obtained depending on the production method, and any toner can be used.
Hereinafter, the toner manufacturing method and the type of toner will be described.

The toner may be produced by any conventionally known method, for example, a toner produced by a polymerization method, a melt suspension method, or the like. Furthermore, a so-called pulverized toner is formed into a sphere by treatment with heat or the like. However, a toner produced by a so-called polymerization method that generates toner particles in an aqueous medium is preferable.
As a method for producing a toner by a so-called polymerization method, a direct toner is used by using a suspension polymerization method described in JP-B-36-10231, JP-A-59-53856, and JP-A-59-61842. And a direct polymerization in the presence of a water-soluble polar polymerization initiator using a water-based organic solvent that is soluble in the monomer and insoluble in the resulting polymer, or directly in the presence of a water-soluble polar polymerization initiator to produce a toner. The toner can be produced using an emulsion polymerization method represented by a soap-free polymerization method. Examples of the polymerization toner include suspension polymerization toner and emulsion polymerization aggregation toner.

<Toner and others>
The charging characteristics of the toner may be negatively charged or positively charged, and can be set according to the method of the image forming apparatus used. The charging characteristics of the toner can be adjusted by the selection and composition ratio of toner base particle components such as a charge control agent, the selection and composition ratio of externally added fine particles, and the like.

  The toner can be used as a one-component developer or can be mixed with a carrier and used as a two-component developer. When used as a two-component developer, the carrier that is mixed with the toner to form the developer may be, for example, a known magnetic substance such as an iron powder-based, ferrite-based, or magnetite-based carrier, or a resin on the surface thereof. A coated one or a magnetic resin carrier can be used. As the carrier coating resin, for example, generally known styrene resins, acrylic resins, styrene acrylic copolymer resins, silicone resins, modified silicone resins, fluorine resins, and the like can be used. Is not to be done.

  The average particle diameter of the carrier is not particularly limited, but those having an average particle diameter of 10 to 200 μm are preferable. These carriers are preferably used at a ratio of 5 to 100 parts by mass with respect to 1 part by mass of the toner. It should be noted that the formation of a full-color image by electrophotography can be carried out in a conventional manner using magenta, cyan, and yellow color toners and, if necessary, black toner.

<Cartridge, image forming apparatus>
Next, a drum cartridge and an image forming apparatus using the electrophotographic photosensitive member of the present invention will be described with reference to FIG.
In FIG. 1, reference numeral 1 denotes a drum-shaped photoconductor, which is driven to rotate about a shaft 2 in the direction of an arrow at a predetermined peripheral speed. The photosensitive member 1 is uniformly charged with a predetermined positive or negative potential on the surface thereof by the charging unit 3 during the rotation process, and then exposure for forming a latent image is performed by the image exposure unit in the exposure unit 4. The formed electrostatic latent image is then developed with toner by the developing means 5, and the toner developed image is sequentially transferred to a transfer body (paper or the like) 7 fed from the paper feeding unit by the corona transfer means 6. . The image-transferred transfer body is then sent to the fixing unit 8 where the image is fixed and printed out of the apparatus. The surface of the photoconductor 1 after the image transfer is cleaned by the cleaning unit 9 to remove the transfer residual toner, and is neutralized by the neutralizing unit 10 for the next image formation.

In using the electrophotographic photoreceptor of the present invention, as a charger, in addition to a corona charger such as corotron and scorotron shown in FIG. 1, a directly charged member to which voltage is applied is brought into contact with the surface of the photoreceptor. Direct charging means for charging may be used. Examples of the direct charging means include a contact charger such as a charging roller and a charging brush. As the direct charging means, any one that involves air discharge or injection charging that does not involve air discharge is possible. Moreover, as a voltage applied at the time of charging, it is possible to use only a direct current voltage or to superimpose an alternating current on a direct current.

For the exposure, a halogen lamp, a fluorescent lamp, a laser (semiconductor, He—Ne), LED, a photoreceptor internal exposure system, or the like is used. As the digital electrophotographic system, it is preferable to use a laser, LED, optical shutter array, or the like. . As the wavelength, in addition to 780 nm monochromatic light, it is possible to use monochromatic light in the 600 to 700 nm region and slightly shorter wavelength.
In the development process, a dry development method such as cascade development, one-component insulating toner development, one-component conductive toner development, two-component magnetic brush development, or the like is used. As the toner, in addition to the pulverized toner, chemical toners such as suspension granulation, suspension polymerization, and emulsion polymerization aggregation can be used. In particular, in the case of chemical toners, those having a small particle diameter of about 4 to 8 μm are used, and those having a shape close to a sphere, and those outside the potato-like sphere can also be used. The polymerized toner is excellent in charging uniformity and transferability, and is preferably used for high image quality.

For the transfer process, electrostatic transfer methods such as corona transfer, roller transfer, and belt transfer, pressure transfer methods, and adhesive transfer methods are used. For fixing, heat roller fixing, flash fixing, oven fixing, pressure fixing, IH fixing, belt fixing, IHF fixing, etc. are used. These fixing methods may be used alone or in combination with a plurality of fixing methods. May be.
For cleaning, brush cleaner, magnetic brush cleaner, electrostatic brush cleaner, magnetic roller cleaner, blade cleaner, etc. are used.

In many cases, the static elimination step is omitted, but when used, a fluorescent lamp, LED, or the like is used, and an exposure energy that is three times or more of the exposure light is often used as the intensity.
In addition to these processes, a pre-exposure process and an auxiliary charging process may be included.
In the present invention, a plurality of components such as the drum-shaped photosensitive member 1, the charging unit 3, the developing unit 5, and the cleaning unit 9 are integrally coupled as a drum cartridge, and the drum cartridge is copied. It may be configured to be detachable from the main body of an electrophotographic apparatus such as a machine or a laser beam printer. For example, at least one of the charging unit 3, the developing unit 5, and the cleaning unit 9 can be integrally supported together with the drum-shaped photoreceptor 1 to form a cartridge.

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist.
[Production Example 1] (Method for producing resin (X) having a polysiloxane structure)
Sodium hydroxide (5.03 g) and H ₂ O (238 ml) were weighed in a 300 mL beaker and dissolved with stirring. 2,3,5-trimethylphenol (0.17 g), 1,1-bis (4-hydroxy-3, methylphenyl) ethane (12.37 g), polysiloxane represented by the following general formula (1-1) A derivative (average degree of polymerization n of polysiloxane n = 32) (2.93 g) and benzyltriethylammonium chloride (0.14 g) were added in this order and dissolved by stirring, and then this aqueous alkaline solution was transferred to a 1 L reaction vessel.

Separately, a mixed solution of diphenyl ether-4,4′-dicarboxylic acid chloride (15.52 g) and dichloromethane (139 mL) was transferred into the dropping funnel. While maintaining the external temperature of the reaction vessel at 20 ° C. and stirring the alkaline aqueous solution in the reaction vessel, the dichloromethane solution was dropped from the dropping funnel over 1 hour. After further stirring for 1 hour, dichloromethane (197 mL) was added and stirring was continued for 3 hours. Thereafter, stirring was stopped and the mixture was allowed to stand for 30 minutes, and then the organic layer was separated. This organic layer was washed twice with 0.1 N aqueous sodium hydroxide solution (238 mL), then washed twice with 0.1 N hydrochloric acid (238 mL), and further demineralized water (238 mL). Was washed twice. Dilution was performed by adding 345 ml of methylene chloride, and the precipitate obtained by pouring into isopropanol (2700 ml) was removed by filtration and dried to obtain a resin (X) having the desired polysiloxane structure. The obtained resin (X) had a viscosity average molecular weight of 49,600. Furthermore, the content of the polysiloxane structure in the polymer was 5.7% by mass as measured by H ¹ -NMR. The structural formula of the obtained resin (X) having a polysiloxane structure is shown below.

[Production Example 2] (Production Method of Resin (Y) Having Polysiloxane Structure)
2- (1). Production of bisphenol Z oligomer
-1,1-bis (4-hydroxy-phenyl) cyclohexane (= bisphenol Z) 100 parts-Sodium hydroxide 78 parts-Water 1490 parts-Methylene chloride 641 parts The said mixture was prepared to the reactor with a stirrer, and was stirred. The reaction was performed by blowing 73 parts of phosgene into this. After completion of the reaction, only the methylene chloride solution containing the polycarbonate oligomer was collected. The analysis results of the resulting oligomeric methylene chloride solution were as follows. Oligomer concentration (Note 1) 18.8% by mass
Terminal chloroformate group concentration (Note 2) 0.47 N Terminal phenolic hydroxyl group concentration (Note 3) 0.01 N (Note 1) Evaporated to dryness and measured.
(Note 2) Aniline hydrochloride obtained by reacting with aniline was subjected to neutralization titration with a 0.1 N aqueous sodium hydroxide solution.
(Note 3) Color development was measured colorimetrically at 546 nm when dissolved in methylene chloride, titanium tetrachloride and acetic acid solutions.

2- (2). Polymerization of polycarbonate-Bisphenol Z oligomer solution obtained in 2- (1) 224 mL
・ Methylene chloride 222mL
-Polysiloxane derivative represented by general formula (1-1) (average degree of polymerization of polysiloxane n = 37) 6.89 g
An aqueous solution prepared by dissolving 8.22 g of sodium hydroxide in 667 mL of water and 2.0 mL of a 2 wt% triethylamine aqueous solution were charged into a 2 L polymerization tank equipped with a stirrer and stirred at 10 ° C., and interfacial polymerization was performed for 4 hours. Subsequently, 274 mL of methylene chloride was added to dilute, and after stirring for 30 minutes, the reaction solution was separated. A methylene chloride solution containing a polycarbonate resin was washed three times with a 0.1N hydrochloric acid aqueous solution, and then washed twice with demineralized water. The precipitate obtained by pouring the washed methylene chloride solution into 5 times (volume) of methanol was taken out by filtration and dried to obtain the desired terminal polysiloxane polycarbonate. This resin is referred to as Resin X.

  In the above formula, A has the following structure.

When the viscosity average molecular weight of this resin was measured according to the following measurement method of viscosity average molecular weight, the viscosity average molecular weight was 43,000. Furthermore, the siloxane content was 12.1% by mass as measured by H ¹ -NMR.
<Measurement method of viscosity average molecular weight>
A sample was dissolved in methylene chloride to prepare a solution having a concentration C of 6.00 g / L. Using an Ubbelohde capillary viscometer with a solvent (methylene chloride) flow time t ₀ of 136.21 seconds, 20.
The flow time t of the sample solution was measured in a constant temperature water bath set at 0 ° C. The viscosity average molecular weight _Mv was calculated according to the following formula.

a = 0.438 × η _sp +1
b = 100 × η _sp / C
η _sp = t / t ₀ −1
C = 6.00 (g / L)
η = b / a
M _v = 3207 × η ^1.205
<Manufacture of developing toner>
Preparation of wax / long chain polymerizable monomer dispersion A1
Paraffin wax (Nippon Seiki Co., Ltd. HNP-9, surface tension 23.5 mN / m, melting point 82 ° C., heat of fusion 220 J / g, melting peak half width 8.2 ° C., crystallization peak half width 13.0 ° C.) 27 Parts (540 g), stearyl acrylate (manufactured by Tokyo Chemical Industry Co., Ltd.) 2.8 parts, 20 mass% sodium dodecylbenzenesulfonate aqueous solution (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., Neogen S20A, hereinafter abbreviated as “20% DBS aqueous solution” as appropriate) 1.9 parts and 68.3 parts of demineralized water were heated to 90 ° C. and stirred with a homomixer (Mark II f model, manufactured by Tokushu Kika Kogyo Co., Ltd.) at a rotation speed of 8000 rpm for 10 minutes. Subsequently, this dispersion was heated to 90 ° C., and circulation emulsification was started under a pressure condition of about 25 MPa using a homogenizer (manufactured by Gorin, 15-M-8PA type). The volume average particle size was dispersed to 250 nm while measuring with “Microtrack UPA”) to prepare a wax / long-chain polymerizable monomer dispersion A1 (emulsion solid content concentration = 30.2 mass%). .

-Preparation of silicone wax dispersion A2
27 parts (540 g) of alkyl-modified silicone wax (melting point: 72 ° C.), 1.9 parts of 20% DBS aqueous solution and 71.1 parts of demineralized water are placed in a 3 L stainless steel container and heated to 90 ° C. to homomixer (Special Machine Industries) The product was stirred for 10 minutes at a rotational speed of 8000 rpm using a Mark II f model manufactured by the company. Next, this dispersion was heated to 99 ° C., and circulation emulsification was started under a pressure condition of about 45 MPa using a homogenizer (manufactured by Gorin Co., Ltd., 15-M-8PA type). A silicone wax dispersion A2 (emulsion solid content concentration = 27.4% by mass) was prepared by dispersing until the particle diameter reached 240 nm.

-Preparation of polymer primary particle dispersion A1
A reactor equipped with a stirrer (three blades), a heating / cooling device, a concentrating device, and a raw material / auxiliary charging device (with an internal volume of 21 liters, an inner diameter of 250 mm, and a height of 420 mm) was mixed with The monomer dispersion A1 was charged with 35.6 parts by mass (712.12 g) and 259 parts of demineralized water, and the temperature was raised to 90 ° C. in a nitrogen stream while stirring at 103 rpm. Thereafter, a mixture of the following monomers and an aqueous emulsifier solution was added over 5 hours from the start of polymerization. The time at which the mixture of the monomers and the aqueous emulsifier solution was started to be dropped was set as the polymerization start, and the following initiator aqueous solution was added over 4.5 hours from 30 minutes after the start of the polymerization. The aqueous agent solution was added over 2 hours, and the mixture was further maintained for 1 hour while maintaining the rotation speed of 103 rpm and the internal temperature of 90 ° C.
[Monomers]
Styrene 76.8 parts (1535.0 g)
Butyl acrylate 23.2 parts Acrylic acid 1.5 parts Trichlorobromomethane 1.0 part Hexanediol diacrylate 0.7 part [Emulsifier aqueous solution]
20% DBS aqueous solution 1.0 part
67.1 parts of demineralized water [initiator aqueous solution]
8% hydrogen peroxide aqueous solution 15.5 parts 8% L (+)-ascorbic acid aqueous solution 15.5 parts [additional initiator aqueous solution]
8% L (+)-ascorbic acid aqueous solution 14.2 parts After the completion of the polymerization reaction, the mixture was cooled to obtain a milky white primary polymer particle dispersion A1. The volume average particle diameter measured by Microtrac UPA was 280 nm, and the solid content concentration was 21.1% by mass.

-Preparation of polymer primary particle dispersion A2
Silicone wax dispersion A2 was placed in a reactor equipped with a stirrer (three blades), a heating / cooling device, a concentrating device, and a raw material / auxiliary charging device (inner volume 21 liters, inner diameter 250 mm, height 420 mm). .6 parts by mass (472.3 g), 20% DBS aqueous solution 1.5 parts by mass, and 324 parts of demineralized water were heated to 90 ° C. under a nitrogen stream, and 8% peroxidation was performed while stirring at 103 rpm. 3.2 parts of an aqueous hydrogen solution and 3.2 parts of an 8% L (+)-ascorbic acid aqueous solution were added all at once. 5 minutes later, polymerization of the following mixture of monomers and emulsifier aqueous solution was started (from the time when 3.2 parts of 8% hydrogen peroxide aqueous solution and 3.2 parts of 8% L (+)-ascorbic acid aqueous solution were added all at once. After 5 minutes, the following initiator aqueous solution was added over 6 hours from the start of polymerization, and the mixture was further maintained for 1 hour while maintaining the rotation speed at 103 rpm and the internal temperature of 90 ° C.
[Monomers]
92.5 parts of styrene (1850.0 g)
Butyl acrylate 7.5 parts Acrylic acid 1.5 parts Trichlorobromomethane 0.6 parts [Emulsifier aqueous solution]
20% DBS aqueous solution 1.5 parts Demineralized water 66.2 parts [Initiator aqueous solution]
8% aqueous hydrogen peroxide solution 18.9 parts 8% L (+)-ascorbic acid aqueous solution 18.9 parts After completion of the polymerization reaction, the mixture was cooled to obtain a milky-white polymer primary particle dispersion A2. The volume average particle diameter measured by Microtrac UPA was 290 nm, and the solid content concentration was 19.0% by mass.

-Preparation of colorant dispersion A
Carbon black (Mitsubishi Chemical Co., Ltd.) manufactured by a furnace method with an ultraviolet capacity of 0.02 in a toluene extract and a true density of 1.8 g / cm ^{3 in} a 300 L internal vessel equipped with a stirrer (propeller blade) Mitsubishi Carbon Black MA100S, 20 parts (40 kg), 20% DBS aqueous solution, 1 part, nonionic surfactant (manufactured by Kao Corporation, Emulgen 120), 4 parts, ion-exchanged water with an electric conductivity of 2 μS / cm, 75 parts And predispersed to obtain a pigment premix solution. The conductivity was measured using a conductivity meter (a personal SC meter model SC72 and a detector SC72SN-11 manufactured by Yokogawa Electric Corporation). The volume cumulative 50% diameter Dv ₅₀ of the carbon black in the dispersion after the premix was about 90 μm. The premix solution was supplied as a raw material slurry to a wet bead mill and subjected to one-pass dispersion. In addition, the inner diameter of the stator was 75 mmφ, the separator diameter was 60 mmφ, the distance between the separator and the disk was 15 mm, and zirconia beads having a diameter of 50 μm (true density 6.0 g / cm ³ ) were used as a dispersion medium. Since the effective internal volume of the stator is about 0.5 liters and the media filling volume is 0.35 liters, the media filling rate is 70%. The rotation speed of the rotor is constant (the peripheral speed of the rotor tip is about 11 m / sec), and the premix slurry is continuously supplied from the supply port by a non-pulsating metering pump at a supply rate of about 50 liters / hr, and from the discharge port. By continuously discharging, a black colorant dispersion A was obtained. The volume average particle diameter measured by Microtrac UPA was 150 nm, and the solid content concentration was 24.2% by mass.

-Production of developing mother particles A Polymer primary particle dispersion A1 95 parts as solids (998.2 g as solids)
Polymer primary particle dispersion A2 5 parts colorant fine particle dispersion A as solid content 6 parts 20% DBS aqueous solution as colorant solid content 0.1 part as solid content Using the above components, the toner was prepared according to the following procedure. Manufactured. Polymer primary particle dispersions A1 and 20 were added to a mixer (volume 12 liter, inner diameter 208 mm, height 355 mm) equipped with a stirrer (double helical blade), heating / cooling device, concentrating device, and raw material / auxiliary charging device. % DBS aqueous solution was charged and mixed uniformly at an internal temperature of 12 ° C. and 40 rpm for 5 minutes. Subsequently, the stirring rotation speed was increased to 250 rpm at an internal temperature of 12 ° C., and 0.52 part of FeSO ₄ .7H ₂ O as a 5% aqueous solution of ferrous sulfate was added over 5 minutes. Was added uniformly over 5 minutes at an internal temperature of 12 ° C. while maintaining 250 rpm, and a 0.5% aqueous solution of aluminum sulfate was added dropwise under the same conditions (the solid content with respect to the resin solid content was 0.00). 10 parts). Thereafter, the temperature was raised to 53 ° C. over 75 minutes at 250 rpm, and then raised to 56 ° C. over 170 minutes.

  Here, when the particle size was measured with a precision particle size distribution measuring apparatus (multisizer III: manufactured by Beckman Coulter, Inc .; hereinafter abbreviated as “multisizer” as appropriate) with an aperture diameter of 100 μm, the 50% volume diameter was 6. It was 7 μm. Thereafter, the polymer primary particle dispersion A2 was added at 250 rpm over 3 minutes and held for 60 minutes, and the rotation speed was reduced to 168 rpm and immediately 20% DBS aqueous solution (6 parts as solid content) was taken over 10 minutes. Added. Further, the internal temperature was raised to 90 ° C. over 30 minutes while maintaining 168 rpm and held for 60 minutes (hereinafter, this step may be referred to as a fusion step).

  Thereafter, the slurry obtained by cooling to 30 ° C. over 20 minutes was extracted, and suction filtration was performed with an aspirator using 5 types C (No5C manufactured by Toyo Roshi Kaisha, Ltd.) filter paper. The cake remaining on the filter paper is transferred to a stainless steel container having an internal volume of 10 L equipped with a stirrer (propeller blade), added with 8 kg of ion-exchanged water having an electric conductivity of 1 μS / cm, and uniformly dispersed by stirring at 50 rpm. Stirred for 30 minutes. Thereafter, suction filtration is again performed with an aspirator using filter paper of type 5 C (No. 5C manufactured by Toyo Roshi Kaisha, Ltd.), and the solid matter remaining on the filter paper is again equipped with a stirrer (propeller blade) and has an electric conductivity of 1 μS / cm. It was transferred to a 10 L container with 8 kg of ion-exchanged water, and evenly dispersed by stirring at 50 rpm and kept stirring for 30 minutes. When this process was repeated 5 times, the electrical conductivity of the filtrate was 2 μS / cm. The conductivity was measured using a conductivity meter (a personal SC meter model SC72 and a detector SC72SN-11 manufactured by Yokogawa Electric Corporation). The cake obtained here was spread on a stainless steel pad so as to have a height of about 20 mm, and dried in a blow dryer set at 40 ° C. for 48 hours to obtain developing mother particles A.

-Production of developing toner A In a Henschel mixer with an internal volume of 10 L (diameter: 230 mm, height: 240 mm) equipped with a stirrer (Z / A ₀ blade) and a deflector oriented perpendicularly to the wall surface from above, the developing mother particles A part (1,000 g) of A was added, followed by 0.5 part of silica fine particles having a volume average primary particle size of 0.04 μm hydrophobized with silicone oil, and volume average primary particles hydrophobized with silicone oil. Toner A for development was obtained by adding 2.0 parts of silica fine particles having a diameter of 0.012 μm, stirring and mixing at 3000 rpm for 10 minutes, and sieving through 150 mesh. The volume average particle diameter of Toner A measured with Multisizer II is 7.05 μm, Dv / D
n was 1.14, and the average circularity measured by FPIA2000 was 0.963.

<Manufacture of photosensitive drum>
[Example 1]
In accordance with the following procedure, a photosensitive drum which is one form of the electrophotographic photosensitive member was produced. The undercoat layer dispersion was produced as follows. That is, a rutile type titanium oxide having an average primary particle size of 40 nm (“TTO55N” manufactured by Ishihara Sangyo Co., Ltd.) and 3% by mass of methyldimethoxysilane (“TSL8117” manufactured by Toshiba Silicone Co., Ltd.) with respect to the titanium oxide were flowed at high speed. In a mixed solvent of methanol / 1-propanol in a mixed solvent of methanol / 1-propanol, which was introduced into a mixing kneader (“SMG300” manufactured by Kawata Co., Ltd.) and mixed at a high rotational speed of 34.5 m / sec. Then, a dispersion slurry of hydrophobized titanium oxide was obtained by dispersing with a ball mill. The dispersion slurry, a mixed solvent of methanol / 1-propanol / toluene, and ε-caprolactam / bis (4-amino-3-methylcyclohexyl) methane / hexamethylenediamine / decamethylenedicarboxylic acid / octadecamethylenedicarboxylic acid The copolyamide pellets having a composition molar ratio of 60% / 15% / 5% / 15% / 5% are stirred and mixed while heating to dissolve the polyamide pellets, and then subjected to ultrasonic dispersion treatment. Therefore, the mass ratio of methanol / 1-propanol / toluene is 7/1/2 and the hydrophobically treated titanium oxide / copolymerized polyamide is contained at a mass ratio of 3/1. A layer dispersion was obtained. The coating liquid for forming the undercoat layer thus obtained was dip-coated on an aluminum cylinder having an outer diameter of 24 mm, a length of 257 mm, and a wall thickness of 0.75 mm whose surface was cut, and the film thickness after drying was as follows. An undercoat layer was formed so as to have a thickness of 2.0 μm.

Next, 10 parts by mass of the phthalocyanine compound was added to 4-methoxy-4-methylpentanone-2.
In addition to 150 parts by mass, the mixture was pulverized and dispersed in a sand grind mill for 1 hour. In addition, 5 wt% of polyvinyl butyral (manufactured by Denki Kagaku Kogyo Co., Ltd., trade name: Denkabutyral # 6000C) 5 wt% 1,2-dimethoxyethane solution and phenoxy resin (Union Carbide, trade name: PKHH) 1 , 100 parts of 2-dimethoxyethane solution was mixed to prepare a binder solution. 100 parts by mass of the binder solution and 1,2-dimethoxyethane were added to 160 parts by mass of the pigment dispersion prepared previously to finally prepare a coating solution for a charge generation layer having a solid content concentration of 4.0%. The dispersion thus obtained was applied on the cylinder on which the undercoat layer was formed so that the film thickness after drying was 0.4 μm to provide a charge generation layer.

Next, a mixture composed of a group of geometric isomer compounds having a structure represented by the following formula [I] as a main component, which is shown in Example 1 of JP-A-2002-80432 as a charge transport material, is used.
0 part by mass, polyarylate A (PAR-A, viscosity average molecular weight 41, consisting of the following repeating structure)
000) 75 parts by mass, 25 parts by mass of the resin X having a polysiloxane structure produced in Production Example 1 and 25 silicone particles having a structure crosslinked to a three-dimensional network structure (trade name: KMP-701, manufactured by Shin-Etsu Chemical Co., Ltd.) The charge transport layer is formed by mixing 4 parts by mass of an antioxidant represented by the following structural formula (I) with 640 parts by mass of a mixed solvent of tetrahydrofuran and toluene (80% by mass of tetrahydrofuran, 20% by mass of toluene). A coating solution was prepared.

This charge transport layer forming coating solution is dip-coated on the above-described charge generation layer so that the film thickness after drying is 15 μm, and dried at 125 ° C. for 20 minutes to form a charge transport layer. Drum DE1 was produced.
[Example 2]
Photosensitive drum DE2 was prepared in the same manner as in Example 1 except that the silicone particle KMP-701 used in the charge transport layer coating solution used in Example 1 was changed to 10 parts by mass.

[Example 3]
Photosensitive drum in the same manner as in Example 1 except that 50 parts by mass of polyarylate A used in the coating solution for charge transport layer used in Example 1 and 50 parts by mass of resin X having a polysiloxane structure were used. Created DE3.
[Example 4]
Photoreceptor drum DE4 in the same manner as in Example 1 except that resin Y having a polysiloxane structure was used instead of resin X having a polysiloxane structure used in the coating solution for charge transport layer used in Example 1. It was created.

[Example 5]
Example except that polyarylate B (PAR-B, viscosity average molecular weight 32,000) having the following repeating structure was used instead of polyarylate A used in the coating solution for charge transport layer used in Example 1. In the same manner as in Example 1, a photosensitive drum DE5 was prepared.

[ Reference Example 6]
Silicone particles used in the charge transport layer coating solution used in Example 1 Instead of KMP-701, silicone particles having a spherical silicone rubber powder surface coated with a silicone resin (trade name: KMP-600, manufactured by Shin-Etsu Chemical Co., Ltd.) The photosensitive drum DE6 was prepared in the same manner as in Example 1 except that (2) was used.

[Comparative Example 1]
A photosensitive drum DC1 was prepared in the same manner as in Example 1 except that the silicone particles used in the coating solution for charge transport layer used in Example 1 were not used.
[Comparative Example 2]
A photosensitive drum DC2 was prepared in the same manner as in Example 1 except that the resin X having a polysiloxane structure used in the coating solution for the charge transport layer used in Example 1 was not used.

[Comparative Example 3]
Similar to Example 1 except that acrylic particles (manufactured by Soken Chemical Co., Ltd., trade name: MP300) were used instead of the silicone particles KMP-701 used in the coating solution for charge transport layer used in Example 1. Thus, a photosensitive drum DC3 was prepared.
[Comparative Example 4]
Other than using Polyarylate A instead of Polyarylate A used in the charge transport layer coating solution used in Example 1, and using Resin Y having a polysiloxane structure instead of Resin X having a polysiloxane structure Produced a photosensitive drum DC4 in the same manner as in Example 1.

<Image evaluation method and slipperiness evaluation method>
The photoconductors prepared in Examples 1 to 5 , Reference Example 6 and Comparative Examples 1 to 4, and the developing toner A are mounted on a black drum cartridge of a color printer (HP Color LaserJet CP2025dn), and the cartridge is mounted on the printer. Attached to. The printer is modified so that the value of the current flowing to the motor that drives the photosensitive member can be measured. Cyan, magenta, and yellow cartridges were not loaded with toner, and the wiper blade and charging roller, which are members that contact the photoconductor, were removed so that the rotational torque was negligible compared to the black cartridge. . By measuring the current value (hereinafter referred to as torque current) flowing to the motor that drives the photoconductor in this way, the slipperiness of the photoconductor to be evaluated was evaluated. The smaller the torque current value, the better the slipperiness.

2,000 sheets of text documents having a printing area of about 5% were formed under the conditions of a temperature of 25 ° C. and a humidity of 50%. Table 2 shows the results of FL, cleaning, sounding, and torque current values at the initial stage and after printing 2,000 sheets.

Claims (5)

In an electrophotographic photoreceptor having an undercoat layer, a charge generation layer, and a charge transport layer on a conductive support, the charge transport layer is an outermost layer, and the outermost layer is a resin having a polysiloxane component, polyarylate Resin and silicone particles , the silicone particles having a three-dimensional network structure.
An electrophotographic photoreceptor, characterized in that it is a polysiloxane having a structure that is cross-linked . The electrophotographic photosensitive member according to claim 1, wherein the content of the silicone particles is 5 to 50 parts by mass with respect to 100 parts by mass of the total binder resin. The polyarylate resin, characterized by having a structural unit represented by the following general formula [A], an electrophotographic photosensitive member according to claim 1 or 2.
Formula [A]

(In the formula [A], Ar ^{3 to} Ar ⁶ each independently represent an arylene group which may have a substituent, z represents a single bond, an oxygen atom, a sulfur atom, or an alkylene group. S is 0. And represents an integer of 2 or less, and y represents a single bond, an oxygen atom, a sulfur atom, or an alkylene group. The electrophotographic photosensitive member according to any one of claims 1 to 3 , a charging unit for charging the electrophotographic photosensitive member, an exposure unit for exposing the charged electrophotographic photosensitive member to form an electrostatic latent image, An electrophotographic photosensitive member cartridge comprising: a developing unit that develops an electrostatic latent image formed on the electrophotographic photosensitive member; and a cleaning unit that cleans the electrophotographic photosensitive member. The electrophotographic photosensitive member according to any one of claims 1 to 3 , a charging unit for charging the electrophotographic photosensitive member, an exposure unit for exposing the charged electrophotographic photosensitive member to form an electrostatic latent image, And an image forming apparatus comprising: a developing unit that develops the electrostatic latent image formed on the electrophotographic photosensitive member.

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