JP2011150011A - Electrophotographic photoreceptor and image forming apparatus using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor having a uniform intermediate layer, capable of preventing the occurrence of defects in image and uneven coating even after its use for a long time, and achieving long service life and satisfactory characteristics of image, and to provide an image forming apparatus with the same. <P>SOLUTION: This electrophotographic photoreceptor 10 includes the intermediate layer 14 between an electrical conductive support and a photosensitive layer, and the intermediate layer contains at least a silicate compound like an inorganic layer. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

The present invention relates to an electrophotographic photosensitive member having an intermediate layer containing an inorganic layered silicate compound (flat silicate) and an image forming apparatus having the same.
More specifically, the present invention comprises an intermediate layer containing smectite, in particular, synthetic smectite (flat silicate), and has a long life with no image defects even when used for a long time and a uniform intermediate layer without coating unevenness. The present invention relates to an electrophotographic photoreceptor capable of realizing the provided good image characteristics and an image forming apparatus provided with the same.

2. Description of the Related Art An electrophotographic image forming apparatus (also referred to as “electrophotographic apparatus”) that forms an image using electrophotographic technology is widely used in copying machines, printers, facsimile machines, and the like.
A photoreceptor used in an electrophotographic process is configured by laminating a photosensitive layer containing a photoconductive material on a conductive support.

Conventionally, a photoconductor (also referred to as “inorganic photoconductor”) having a photosensitive layer mainly composed of an inorganic photoconductive material has been widely used. However, it is resistant to heat resistance, storage stability, human body and environment. It has defects in any of the aspects of toxicity, sensitivity, durability, occurrence of image defects, productivity, manufacturing cost, etc., and satisfactory products are not obtained in all points.
On the other hand, research and development of a photoreceptor (also referred to as “organic photoreceptor”) having a photosensitive layer mainly composed of an organic photoconductive material has progressed, and now it occupies the mainstream of photoreceptors.

  Organic photoreceptors have some problems in sensitivity, durability, and environmental stability, but have many advantages over inorganic photoreceptors in terms of toxicity, manufacturing cost, and freedom of material design. Have. For example, an organic photoreceptor can form a photosensitive layer by an easy and inexpensive method typified by a dip coating method.

  As an organic photoconductor, a charge generation material and a charge transport material (also referred to as “charge transfer material”) are dispersed on a conductive support in a binder resin (also referred to as “binder resin” or “binder resin”). A single-layer type photosensitive layer, a charge generation layer in which a charge generation material is dispersed in a binder resin on a conductive support, and a charge transport layer in which a charge transport material is dispersed in a binder resin in this order, Alternatively, a laminated photosensitive layer or a reverse laminated photosensitive layer formed in the reverse order has been proposed. Among these, the function-separated type photoconductor having a laminated type photosensitive layer and a reverse laminated type photosensitive layer is excellent in electrophotographic characteristics and durability, has a high degree of freedom in material selection, and can be designed in various ways. Widely used.

  When the photosensitive layer is applied and formed directly on the conductive support in the production of an organic photoreceptor, the photosensitive layer is easily affected by the surface of the conductive support, and it is difficult to form a uniform and uniform film. For this reason, there has been a problem that film thickness unevenness occurs and causes various image defects and density unevenness.

  In addition, in an organic photoreceptor having a laminated photosensitive layer, since the conductive support and the charge generation layer are in direct contact with each other, when an electric field is applied by charging, a charge is generated in a part of the charge generation material. However, when the charge generating substance is present nearby, the potential is locally lowered, and there is a problem that fogging or the like occurs on the white paper or the gray portion in the reversal development.

As a countermeasure against the above problems, it is known that it is effective to provide a resin layer called an intermediate layer (also referred to as “undercoat layer”) between the conductive support and the photosensitive layer.
For example, a layer obtained by applying and drying an alcohol-soluble polyamide resin as an intermediate layer has been proposed (see, for example, JP-A-52-25638: Patent Document 1).

  However, even if such an intermediate layer is provided, good electrical characteristics and image quality can be obtained in a normal environment, but these alcohol-soluble resins have a large resistance change due to the environment such as temperature and humidity. In addition, there is a problem that defects such as black spots, memory, and density unevenness occur on the image.

Therefore, a layer containing titanium oxide has been proposed as an intermediate layer (see, for example, JP-A-56-52757: Patent Document 2).
For the purpose of improving image characteristics, a technique using surface-treated titanium oxide is known in order to improve the dispersibility of titanium oxide in the intermediate layer coating solution.
In addition to titanium oxide, alumina, silica and the like have been used as the inorganic fine particles used for the intermediate layer.

In addition, the inorganic fine particles are generally granular, but are also known as needles or discs. Among them, inorganic layered silicate compounds are known as inorganic fine particles that are not granular, and are applied in the paint and cosmetic fields. Examples of electrophotographic photosensitive members in which such inorganic layered silicate compounds are added to the photosensitive layer (Patent Documents 3 and 4), and examples of electrophotographic photosensitive members added to the surface protective layer (Patent Document 5). )
However, these are examples when used for the surface layer of an electrophotographic photosensitive member, and application to an intermediate layer has not yet been studied.

JP-A-52-25638 JP-A-56-52757 JP-A-7-152166 Japanese Patent Laid-Open No. 9-54446 JP 2007-64998 A

Thus, when it is intended to suppress the injection of charges from the conductive support by the intermediate layer and prevent image defects due to a local potential decrease, the thicker the intermediate layer, the greater the effect.
In addition, the conductive support is usually machined, but attempts have been made to use an uncut support from the viewpoint of cost reduction. In this case, the influence of the unevenness of the support is excluded. The intermediate layer needs to be thicker for smoothing.

However, when thickly applied by dip coating, dripping occurs and it is difficult to apply uniformly.
On the other hand, a solvent having a high evaporation rate has been used. However, there is a problem that a uniform coating film cannot be formed even if the same photosensitive member has a different drying rate depending on the air blowing position.

  In addition, the optimization of the coating liquid properties for realizing a uniform coating film has been conventionally performed by delicate adjustment by the three of resin, fine particles, and solvent, and the adjustment range has been narrow and difficult. In addition, the oxide fine particles were liable to settle when left standing, and the storage stability of the coating solution, so-called pot life, was short.

  As a result of intensive studies in order to solve the above problems, the present inventor has found that these problems can be solved by using a flat silicate for the intermediate layer, and has completed the present invention.

  Thus, according to the present invention, there is provided an intermediate layer between the conductive support and the photosensitive layer, and the intermediate layer contains at least the inorganic layered silicate compound. Is provided.

In addition, according to the present invention, there is provided the electrophotographic photosensitive member, wherein the inorganic layered silicate compound is smectite.
In addition, according to the present invention, there is provided the electrophotographic photosensitive member, wherein the inorganic layered silicate compound is a synthetic smectite.

In addition, according to the present invention, there is provided the electrophotographic photosensitive member, wherein the inorganic layered silicate compound is a flat silicate.
According to the invention, the inorganic layered silicate compound has a number average particle diameter of 0.1 μm to
The electrophotographic photosensitive member is a powder having 2 μm.

In addition, according to the present invention, there is provided the electrophotographic photosensitive member, wherein the inorganic layered silicate compound is contained in an amount of 50% by weight to 200% by weight with respect to the binder resin.
Further, according to the present invention, there is provided the electrophotographic photosensitive member, wherein the intermediate layer has a thickness of 10 μm to 20 μm.
The present invention also provides the electrophotographic photosensitive member, wherein the intermediate layer has at least a two-layer structure.
In addition, according to the present invention, the electrophotographic photosensitive member is described in which the electrophotographic photosensitive member is constituted by a non-cutting support.

  Further, according to the present invention, the electrophotographic photosensitive member described above, a charging unit that charges the electrophotographic photosensitive member, and an exposing unit that exposes the charged electrophotographic photosensitive member to form an electrostatic latent image; An image comprising: a developing unit that develops and visualizes the electrostatic latent image formed by exposure; and a transfer unit that transfers the image visualized by the development onto a recording medium. A forming apparatus is provided.

The inorganic layered silicate compound (flat silicate) used in the present invention has a large thickening effect even in a small amount, and the viscosity of the coating solution can be easily adjusted. In particular, an intermediate layer of a uniform thick coating film, which has been difficult in the past, can be easily manufactured. Moreover, the selection range of the coating method is wide because of easy viscosity adjustment. Moreover, since it has the characteristic that it does not settle even if it leaves still, a coating liquid can be used stably for a long period of time.
The inorganic layered silicate compound (flat silicate) contained in the intermediate layer of the electrophotographic photosensitive member according to the present invention has a large thickening effect even in a small amount, and the viscosity of the coating solution can be easily adjusted. By providing, it is possible to realize good image characteristics without uneven coating, and when manufacturing a photoreceptor using an inexpensive uncut raw material as a material, by laminating the intermediate layer on a conductive support, It is possible to provide an electrophotographic photosensitive member capable of realizing good image characteristics without uneven coating due to the unevenness of the film and an image forming apparatus including the same.

Further, according to the present invention, since a thick intermediate layer can be formed, an uncut support, that is, an inexpensive blank tube is used as a conductive support without using a cut conductive support as a material. However, it is possible to provide a photoconductor capable of realizing a uniform coating film free from uneven coating due to the unevenness of the raw tube and realizing good image characteristics.
In addition, the coating liquid for coating and forming the intermediate layer of the photoreceptor of the present invention can maintain a desired dispersion state for a long period of time, and can form a coating film without coating unevenness even after long-term storage. it can.

FIG. 2 is a schematic cross-sectional view showing a configuration of a main part of the electrophotographic photosensitive member of the present invention. FIG. 2 is a schematic cross-sectional view showing a configuration of a main part of the electrophotographic photosensitive member of the present invention. FIG. 3 is a schematic cross-sectional view showing a configuration of a main part of the electrophotographic photosensitive member of the present invention. 1 is a schematic side view illustrating a configuration of an image forming apparatus of the present invention.

The electrophotographic photoreceptor of the present invention comprises an intermediate layer between the conductive support and the photosensitive layer, and contains at least an inorganic layered silicate compound (flat silicate) in the intermediate layer.
The inorganic silicate compound (flat silicate) used in the present invention means a layered silicate containing alkali, alkaline earth metal, aluminum, and the like, and includes kaolin mineral, mica clay mineral, and smectite.

Kaolin minerals include kaolinite, dickite, nacrite, halloysite and serpentine.
Examples of the mica clay mineral include pyrophyllite, talc, muscovite, swellable synthetic fluorine mica, sericite, and chlorite.

  Examples of the smectite include smectite, vermiculite, swellable synthetic fluorine vermiculite, and montmorillonite group minerals.

Among these, smectite is preferable. There are two types of smectites: natural smectites and synthetic smectites.
Examples of natural smectites include montmorillonite and beidellite, which are obtained as clays called bentonite and acid clay.

However, a synthetic product is most preferably used because of its excellent transparency. Specific examples of synthetic smectites include hydrophilic lucentite (trade name) SWN and SWF manufactured by Corp Chemical Co., Ltd. Examples thereof include Lucentite (trade name) SAN, SEN and SPN modified to be oily.
These inorganic layered silicate compounds are preferably powders having a number average particle size of 0.1 μm to 2 μm.

The intermediate layer of the photoreceptor of the present invention contains at least a plate-like silicate and a binder resin, and may contain additives such as an antioxidant and a conductive agent as necessary.
Moreover, you may add the conventional oxide fine particle in the range which does not prevent the effect of flat silicate.

As the resin used for the intermediate layer, for example, phenol resin, polyurethane, polyamide, polyimide, polyamideimide, polyamic acid, polyvinyl acetal, epoxy resin, acrylic resin, melamine resin or polyester is preferable. These resins may be used alone or in combination of two or more. These resins have good adhesion to the support, improve the dispersibility of the oxide fine particles, and have good solvent resistance after film formation.
Of these resins, a polyamide resin is particularly preferable. A leveling agent may be added to the intermediate layer in order to enhance surface properties.
Examples of such commercially available polyamide resins include trade name: Ultramid 1c (manufactured by BASF), trade name: Amilan CM8000 (manufactured by Toray Industries, Inc.), and the like.

The thickness of the intermediate layer is 0.5 μm to 30 μm, preferably 10 μm to 20 μm.
The intermediate layer of the present invention smoothes the unevenness of the conductive support or scatters the reflected light, and free carriers from the conductive support prevent injection. When the free carrier reaches the photosensitive layer, the charging ability of the photosensitive member is lowered, and the image characteristics are greatly affected. When the thickness of the intermediate layer is increased, the effect of preventing free carriers is improved, but the resistance becomes too large and the sensitivity is lowered. Therefore, there is a method of functionally separating a thick intermediate layer with high conductivity for smoothing the surface of the support and a high resistance thin film intermediate layer that blocks free carriers. Thus, the surface of the support can be smoothed while effectively suppressing free carrier injection.

  The intermediate layer is prepared by dissolving or dispersing tabular silicate particles, a binder resin and, if necessary, an additive in an organic solvent to prepare a coating solution for forming an intermediate layer, and this coating solution is applied to the surface of the conductive support. It can be formed by drying and removing the organic solvent.

Specifically, a coating solution for forming an intermediate layer can be prepared by dissolving a binder resin in an organic solvent, and adding and dispersing the plate-like silicate particles of the present invention in the resulting solution.
In order to disperse the titanium oxide particles in the solution, treatment may be performed using a ball mill, a sand mill, a roll mill, a paint shaker, an attritor, an ultrasonic disperser, or the like.

  The content of the flat silicate in the intermediate layer is preferably 20 to 1000 parts by weight, more preferably 50 to 500 parts by weight, and further 50 to 200 parts by weight with respect to 100 parts by weight of the binder resin. And is particularly preferably 50 to 100 parts by weight.

  When the content of the flat silicate in the intermediate layer is within the above range, the balance between the effect of adjusting the viscosity of the coating solution by the flat silicate and the electrical characteristics can be improved.

  Examples of the organic solvent include lower alcohols such as methanol, ethanol, n-propyl alcohol, isopropyl alcohol, n-butanol, tert-butanol and sec-butanol. Among these, methanol and ethanol are particularly preferable in terms of the solubility of the polyamide resin and the coating property of the prepared coating solution.

  In the coating solution for forming the intermediate layer, the lower alcohol solvent is preferably 30 to 100% by weight, more preferably 40 to 100% by weight, and 50 to 100% by weight in all the solvents. Particularly preferred.

In preparation of the coating solution for forming the intermediate layer, toluene, methylene chloride, cyclohexanone, tetrahydrofuran or the like may be used in combination as a cosolvent for adjusting the solvent evaporation rate.
The amount of the co-solvent used is suitably about 5 to 30% by weight of the organic solvent.

  The coating method for the intermediate layer forming coating solution may be appropriately selected in consideration of the physical properties and productivity of the coating solution, for example, dip coating method, spray method, nozzle method, bar coating method, Examples thereof include a roll coating method, a blade method, a ring method, and a dip coating method.

  Among these coating methods, the dip coating method is a method of forming a layer on the surface of the substrate by immersing the substrate in a coating tank filled with a coating solution and then pulling it up at a constant speed or a speed that changes sequentially. Since it is relatively simple and excellent in terms of productivity and cost, it can be suitably used for the production of a photoreceptor. In order to stabilize the dispersibility of the coating liquid, the apparatus used for the dip coating method may be provided with a coating liquid dispersing apparatus represented by an ultrasonic generator.

  From the above, the intermediate layer of the photoreceptor of the present invention is preferably formed by a coating method using a coating solution in which flat silicate particles and a binder resin are dissolved or dispersed in a solvent comprising a lower alcohol.

Although it will not specifically limit if the temperature in the drying process of a coating film is the temperature which can remove the used organic solvent, 50-140 degreeC is suitable and 80-130 degreeC is especially preferable.
When the drying temperature is less than 50 ° C., the drying time may be long. On the other hand, if the drying temperature exceeds 140 ° C., the electrical characteristics during repeated use of the photoreceptor may deteriorate and the resulting image may deteriorate.
The temperature conditions in the production of such a photosensitive layer are common not only in the intermediate layer but also in the formation of layers such as a photosensitive layer described later and other processes.

Next, the configuration of the photoreceptor of the present invention will be specifically described.
1 to 3 are schematic cross-sectional views each showing a configuration of a main part of the photoreceptor of the present invention.
In the photoreceptor 10 of FIG. 1, an intermediate layer 14, a charge generation layer 12, and a charge transport layer 11 are formed in this order on a conductive support 15.

  In the photoconductor 20 of FIG. 2, an intermediate layer 24, a second intermediate layer 23, a charge generation layer 22, and a charge transport layer 21 are formed in this order on a conductive support 25.

  In the photoconductor 26 of FIG. 3, an intermediate layer 29, a charge generation layer 28, and a charge transport layer 27 are formed in this order on a conductive support 30.

  The photosensitive layer of the photoreceptor of the present invention includes at least an intermediate layer of the present invention, a stacked photosensitive layer in which a charge generation layer containing a charge generation material and a charge transport layer containing a charge transport material are laminated in this order, As in 2, a second intermediate layer may be further provided between the intermediate layer and the charge generation layer.

The structure other than the intermediate layer in the photoreceptor of the present invention will be described.
[Conductive supports 15, 25, 30]
The constituent material of the conductive support is not particularly limited as long as it has a function as an electrode and a function as a support member of the multilayer photoreceptor (photoreceptor) 1 and is a material used in this field.

  Specifically, metallic materials such as aluminum, aluminum alloys, copper, zinc, stainless steel, and titanium: supports made of polymer materials such as polyethylene terephthalate, polyamide, polyester, polyoxymethylene, polystyrene, hard paper, glass, etc. Examples include those obtained by laminating a metal foil on the surface, those obtained by vapor-depositing a metal material, and those obtained by evaporating or applying a layer of a conductive compound such as a conductive polymer, tin oxide, or indium oxide.

  The shape of the conductive support is not limited to a cylindrical shape (drum shape) as shown in FIG. 4, and may be a sheet shape, a columnar shape, an endless belt shape, or the like. In the case of a cylindrical shape, there is a drawing tube by the porthole method.

  If necessary, the surface of the conductive support is subjected to irregular reflection treatment such as anodizing film treatment, surface treatment with chemicals, hot water, coloring treatment, and surface roughening within a range that does not affect the image quality. However, if the intermediate layer of the present invention is applied thickly, the effects of surface irregularities and reflections can be eliminated, so that the treatment does not have to be performed.

  The irregular reflection treatment is particularly effective when the photoreceptor according to the present invention is used in an electrophotographic process using a laser as an exposure light source. That is, in the electrophotographic process using a laser as an exposure light source, the wavelength of the laser beam is uniform, so the laser beam reflected on the surface of the photoconductor and the laser beam reflected inside the photoconductor cause interference, Interference fringes due to this interference may appear in the image and cause image defects. Therefore, by performing irregular reflection processing on the surface of the conductive support, it is possible to prevent image defects due to interference of laser light having a uniform wavelength.

[Charge generation layers 12, 22, 28]
The charge generation layer contains a charge generation material that generates charges by absorbing light such as semiconductor laser light.

  Substances effective as a charge generating substance include azo pigments such as monoazo pigments, bisazo pigments and trisazo pigments; indigo pigments such as indigo and thioindigo; perylene pigments such as peryleneimide and perylene anhydride; anthraquinone and Polycyclic quinone pigments such as pyrenequinone; metal phthalocyanines such as oxotitanium phthalocyanine and phthalocyanine pigments such as metal-free phthalocyanine; organic photoconductive materials such as squarylium dyes, pyrylium salts, thiopyrylium salts, triphenylmethane dyes; and selenium Inorganic photoconductive materials such as amorphous silicon and the like can be used, and materials having sensitivity in the exposure wavelength region can be appropriately selected and used. These charge generation materials can be used alone or in combination of two or more.

  In order to improve the function of the charge generating substance, it is represented by triphenylmethane dyes represented by methyl violet, crystal violet, knight blue and victoria blue, erythrosine, rhodamine B, rhodamine 3R, acridine orange and frappeosin. Sensitizing dyes such as acridine dyes, thiazine dyes typified by methylene blue and methylene green, oxazine dyes typified by capri blue and meldra blue, cyanine dyes, styryl dyes, pyrylium salt dyes or thiopyrylium salt dyes They can be used in combination.

  The ratio of use of the sensitizing dye is not particularly limited, but is preferably 10 parts by weight or less, particularly preferably 0.5 to 2.0 parts by weight with respect to 100 parts by weight of the charge generating material.

The charge generation layer may contain a binder resin for the purpose of improving the binding property.
As the binder resin, a resin having a binding property used in this field can be used, and a binder resin having excellent compatibility with the charge generation material is preferable.

  Specifically, polyester resin, polystyrene resin, polyurethane resin, phenol resin, alkyd resin, melamine resin, epoxy resin, silicone resin, acrylic resin, methacrylic resin, polycarbonate resin, polyarylate resin, phenoxy resin, polyvinyl butyral resin, polyvinyl Formal resins, copolymer resins containing two or more of the repeating units constituting these resins, and the like can be mentioned. Examples of the copolymer resin include insulating resins such as vinyl chloride-vinyl acetate copolymer resin, vinyl chloride-vinyl acetate-maleic anhydride copolymer resin, and acrylonitrile-styrene copolymer resin. The binder resin is not limited to these, and a resin generally used in this field can be used as the binder resin. These binder resins can be used alone or in combination of two or more.

  The use ratio of the binder resin is not particularly limited, but is about 0.5 to 2.0 parts by weight with respect to 1 part by weight of the charge generation material.

  The charge generation layer is selected from hole transport materials, electron transport materials, antioxidants, ultraviolet absorbers, dispersion stabilizers, sensitizers, leveling agents, plasticizers, fine particles of inorganic compounds or organic compounds, as necessary. An appropriate amount of one or more of them may be included.

The charge generation layer can be formed by a known dry method and wet method.
Examples of the dry method include a method of vacuum-depositing a charge generating material on an intermediate surface formed on a conductive support.

  As a wet method, for example, a charge generation material and, if necessary, a binder resin are dissolved or dispersed in an appropriate organic solvent to prepare a coating solution for forming a charge generation layer, and this coating solution is formed on a conductive support. The method of apply | coating to the surface of the intermediate | middle layer made and then drying and removing an organic solvent is mentioned.

  Examples of the solvent used in the charge generation layer coating solution include halogenated hydrocarbons such as dichloromethane and dichloroethane; ketones such as acetone, methyl ethyl ketone and cyclohexanone; esters such as ethyl acetate and butyl acetate; tetrahydrofuran (THF) , Ethers such as dioxane; alkyl ethers of ethylene glycol such as 1,2-dimethoxyethane; aromatic hydrocarbons such as benzene, toluene and xylene; N, N-dimethylformamide, N, N-dimethylacetamide, etc. Examples include aprotic polar solvents. Among these solvents, non-halogen organic solvents are preferably used in consideration of the global environment. These solvents can be used alone or in combination of two or more.

  Prior to dissolving or dispersing the charge generation material in the solvent, the charge generation material may be previously pulverized by a pulverizer. Examples of the pulverizer used for the pulverization treatment include a ball mill, a sand mill, an attritor, a vibration mill, and an ultrasonic disperser.

Dispersers such as paint shakers, ball mills, and sand mills can be used to dissolve or disperse the charge generating material in the solvent. At this time, it is preferable to appropriately set the dispersion condition so that impurities are generated from the container and the members constituting the disperser due to wear and the like and are not mixed into the coating liquid.
Other steps and conditions are in accordance with the formation of the intermediate layer.

The thickness of the charge generation layer is not particularly limited, but is preferably 0.05 to 5 μm, particularly preferably 0.1 to 1 μm.
If the thickness of the charge generation layer is less than 0.05 μm, the light absorption efficiency is lowered, and the sensitivity of the photoreceptor may be lowered. On the other hand, if the thickness of the charge generation layer exceeds 5 μm, the charge transfer inside the charge generation layer becomes a rate-determining step in the process of erasing the charge on the surface of the photosensitive layer, which may reduce the sensitivity of the photoreceptor.

[Charge transport layers 11, 21, 27]
The charge transport layer has a function of transporting charges generated in the charge generation layer to the surface of the photoreceptor.
The charge transport layer contains at least a charge transport material and a binder resin.

As the charge transport material, high molecular compounds such as polyvinyl carbazole, polyvinyl pyrene, and polyacenaphthylene, or low molecular compounds such as various pyrazoline derivatives, oxazole derivatives, hydrazone derivatives, stilbene derivatives, and arylamine derivatives can be used.
Binder resins include polymers and copolymers of vinyl compounds such as styrene, vinyl acetate, vinyl chloride, acrylic ester, methacrylic ester, vinyl alcohol, ethyl vinyl ether, polyvinyl acetal, polycarbonate, polyester, polyamide, polyurethane, cellulose Examples include ether, phenoxy resin, silicon resin, and epoxy resin.

  As the binder resin, a transparent resin that does not absorb the light from the exposure light source of the image forming apparatus can be used among the resins having binding properties used in this field, and a resin similar to that contained in the charge generation layer can be used. One kind can be used alone or two or more kinds can be used in combination.

Among these, polystyrene, polycarbonate, polyarylate, and polyphenylene oxide are preferable because they have a volume resistance of 10 ¹³ Ω or more, excellent electrical insulation, and excellent film formability, potential characteristics, and the like, and polycarbonate is particularly preferable. .

The use ratio of the binder resin is not particularly limited, but is about 50 to 300 parts by weight with respect to 100 parts by weight of the charge transport material.

  The charge transport layer is selected from a hole transport material, an electron transport material, an antioxidant, an ultraviolet absorber, a dispersion stabilizer, a sensitizer, a leveling agent, a plasticizer, an inorganic compound, or an organic compound as necessary. An appropriate amount of one or more of them may be included.

Similarly to the charge generation layer, the charge transport layer can be formed by preparing a coating solution for forming a charge transport layer and using a wet method, particularly a dip coating method.
As the solvent used for the preparation of the coating solution for forming the charge transport layer, it is possible to use one kind of the same solvents as those used for the preparation of the coating solution for forming the charge generation layer alone or in combination of two or more kinds. it can.

  Specifically, alcohols such as methanol, ethanol, isopropanol and butanol; aliphatic hydrocarbons such as n-hexane, octane and cyclohexane; aromatic hydrocarbons such as benzene, toluene and xylene; dichloromethane, dichloroethane and carbon tetrachloride Halogenated hydrocarbons such as chlorobenzene; ethers such as dimethyl ether, diethyl ether, tetrahydrofuran, dioxane, dioxolane, propylene glycol monomethyl ether, ethylene glycol dimethyl ether, and diethylene glycol dimethyl ether; ketones such as acetone, methyl ethyl ketone, and cyclohexanone; ethyl acetate, acetic acid Esters such as methyl; dimethylformaldehyde, dimethylformamide, dimethylsulfoxide, etc. Among these, it is particularly preferable to use tetrahydrofuran and 1,3-dioxolane alone.

Other steps and conditions are in accordance with the formation of the intermediate layer and the charge generation layer.
Although the film thickness of a charge transport layer is not specifically limited, 5-40 micrometers is preferable and 10-30 micrometers is especially preferable.
When the thickness of the charge transport layer is less than 5 μm, the charge holding ability on the surface of the photoreceptor is lowered, and the contrast of the output image may be lowered. On the other hand, if the thickness of the charge transport layer exceeds 40 μm, the productivity of the photoreceptor may be lowered.

  The image forming apparatus of the present invention includes a photosensitive member of the present invention, a charging unit that charges the electrophotographic photosensitive member, an exposure unit that exposes the charged electrophotographic photosensitive member to form an electrostatic latent image, The image forming apparatus includes a developing unit that develops and visualizes the electrostatic latent image formed by the exposure, and a transfer unit that transfers the image visualized by the development onto a recording medium.

The image forming apparatus of the present invention and the operation thereof will be described with reference to the drawings, but are not limited to the following description.
FIG. 4 is a schematic side view showing the configuration of the image forming apparatus of the present invention.

  An image forming apparatus (laser printer) 100 in FIG. 4 includes a photoreceptor 1 of the present invention, an exposure unit (semiconductor laser) 31, a charging unit (charging unit) 32, a developing unit (developing unit) 33, and a transfer unit. The image forming apparatus includes a (transfer charger) 34, a conveyance belt (not shown), a fixing unit (fixing unit) 35, and a cleaning unit (cleaner) 36. Reference numeral 51 indicates a transfer sheet.

  The photosensitive member 1 is rotatably supported by the main body of the image forming apparatus 100 (not shown), and is driven to rotate in the direction of the arrow 41 around the rotation axis 44 by a driving unit (not shown). The drive means includes, for example, an electric motor and a reduction gear, and transmits the driving force to a conductive support constituting the core of the photoconductor 1 to drive the photoconductor 1 to rotate at a predetermined peripheral speed. . The charger 32, the exposure unit 31, the developing unit 33, the transfer charger 34, and the cleaner 36 are arranged in this order from the upstream side in the rotation direction of the photosensitive member 1 indicated by an arrow 41 along the outer peripheral surface of the photosensitive member 1. It is provided toward the downstream side.

The charger 32 is a charging unit that uniformly charges the outer peripheral surface of the photoreceptor 1 to a predetermined potential.
The exposure means 31 includes a blue semiconductor laser as a light source, and is irradiated with a laser beam emitted from the light source to the surface of the photosensitive member 1 between the charger 32 and the developer 33, thereby charging the photosensitive member. The outer peripheral surface of the body 1 is exposed according to image information. The light is repeatedly scanned in the main scanning direction in the direction in which the rotation axis 44 of the photoconductor 1 extends, and these are imaged to form an electrostatic latent image on the surface of the photoconductor 1 in sequence. That is, the charge amount of the photoreceptor 1 uniformly charged by the charger 32 is different depending on whether the laser beam is irradiated or not, and an electrostatic latent image is formed.

  The developing unit 33 is a developing unit that develops an electrostatic latent image formed on the surface of the photoconductor 1 by exposure with a developer (toner), and is provided facing the photoconductor 1. A developing roller 33a for supplying toner to the toner, and a casing 33b for supporting the developing roller 33a so as to be rotatable about a rotation axis parallel to the rotation axis 44 of the photosensitive member 1 and containing a developer containing toner in the internal space thereof. Prepare.

  The transfer charger 34 supplies a toner image, which is a visible image formed on the outer peripheral surface of the photoreceptor 1 by development, between the photoreceptor 1 and the transfer charger 34 from the direction of the arrow 42 by a conveying unit (not shown). It is a transfer means to transfer on the transfer paper 51 which is a recording medium. The transfer charger 34 is, for example, a non-contact type transfer unit that includes a charging unit and transfers the toner image onto the transfer paper 51 by giving the transfer paper 51 a charge having a polarity opposite to that of the toner.

  The cleaner 36 is a cleaning unit that removes and collects toner remaining on the outer peripheral surface of the photoconductor 1 after the transfer operation by the transfer charger 34, and a cleaning blade 36 a that peels off the toner remaining on the outer peripheral surface of the photoconductor 1; A recovery casing 36b for storing the toner separated by the cleaning blade 36a. The cleaner 36 is provided together with a static elimination lamp (not shown).

Further, the image forming apparatus 100 is provided with a fixing device 35 as fixing means for fixing the transferred image on the downstream side where the transfer paper 51 that has passed between the photoreceptor 1 and the transfer charger 34 is conveyed. It is done. The fixing device 35 includes a heating roller 35a having a heating unit (not shown), and a pressure roller 35b that is provided facing the heating roller 35a and is pressed by the heating roller 35a to form a contact portion.
Reference numeral 37 denotes a separating unit that separates the transfer paper and the photosensitive member, and reference numeral 38 denotes a casing that houses each unit of the image forming apparatus.

The image forming operation by the electrophotographic apparatus 100 is performed as follows.
First, when the photosensitive member 1 is rotationally driven in the direction of the arrow 41 by the driving unit, the photosensitive member 1 is provided by the charger 32 provided on the upstream side in the rotational direction of the photosensitive member 1 with respect to the light imaging point by the exposure unit 31. Is uniformly charged to a predetermined negative potential.
Next, light corresponding to image information is irradiated from the exposure unit 32 to the surface of the photoreceptor 1. In this exposure, the surface charge of the portion irradiated with light is removed by this exposure, and a difference occurs between the surface potential of the portion irradiated with light and the surface potential of the portion not irradiated with light. A latent image is formed.

Toner is supplied to the surface of the photosensitive member 1 on which the electrostatic latent image is formed from a developing device 33 provided on the downstream side in the rotation direction of the photosensitive member 1 with respect to the light image formation point by the exposure means 33, and the electrostatic latent image Is developed to form a toner image.
In synchronization with the exposure of the photoreceptor 1, the transfer paper 51 is supplied between the photoreceptor 1 and the transfer charger 34. The transfer charger 34 applies a charge having a polarity opposite to that of the toner to the supplied transfer paper 51, and the toner image formed on the surface of the photoreceptor 1 is transferred onto the transfer paper 51.

  The transfer paper 51 onto which the toner image has been transferred is conveyed to the fixing device 35 by the conveying means, and is heated and pressurized when passing through the contact portion between the heating roller 35a and the pressure roller 35b of the fixing device 35, and the toner The image is fixed on the transfer paper 51 and becomes a robust image. The transfer paper 51 on which the image is formed in this manner is discharged to the outside of the electrophotographic apparatus 100 by the conveying means.

  On the other hand, the toner remaining on the surface of the photoreceptor 1 even after the transfer of the toner image by the transfer charger 34 is separated from the surface of the photoreceptor 1 by the cleaner 36 and collected. The charge on the surface of the photoreceptor 1 from which the toner has been removed in this manner is removed by the light from the static elimination lamp, and the electrostatic latent image on the surface of the photoreceptor 1 disappears. Thereafter, the photosensitive member 1 is further driven to rotate, and a series of operations starting from charging is repeated to form images continuously.

  The present invention will be specifically described below with reference to production examples, examples and comparative examples, but the present invention is not limited to these production examples and examples.

Example 1
Production of Photoreceptor Shown in FIG. 1 8 parts by weight of a plate-like silicate, Lucentite SPN (manufactured by Corp Chemical) and a commercially available polyamide resin (trade name: Ultramid 1c, BASF, 8 weight) The coating solution was added to 84 parts by weight of methyl alcohol and dispersed for 8 hours with a paint shaker to prepare a coating solution for forming an intermediate layer (3 kg), and the viscosity was 20 mPa · s.

  The obtained coating solution for forming an intermediate layer is filled in a coating tank, and an aluminum drum-like support having a diameter of 30 mm and a total length of 340 mm is immersed as a conductive support, and then pulled up and dried naturally to form an intermediate layer having a thickness of 10 μm. Formed.

Next, titanyl phthalocyanine (manufactured by Permachem Asia Co., Ltd.) having an X-ray diffraction spectrum in which the Bragg angle (2θ ± 0.2 °) with respect to X-rays of CuKα 1.541 と し て as a charge generating substance shows a main peak at 27.3 °. ) 1 part by weight and 1 part by weight of butyral resin (trade name: # 6000-C, manufactured by Denki Kagaku Kogyo Co., Ltd.) as a binder resin were mixed with 98 parts by weight of methyl ethyl ketone, and dispersed for 8 hours with a paint shaker to generate charges. A layer forming coating solution (3 kg) was prepared.
The titanyl phthalocyanine having an X-ray diffraction spectrum showing a main peak at 27.3 ° used in this example is a so-called Y-type titanyl phthalocyanine, and can be purchased from, for example, Permachem Asia.

The obtained coating solution for forming a charge generation layer was applied to the surface of the intermediate layer previously provided by the same method as that for forming the intermediate layer, and then naturally dried to form a charge generation layer having a thickness of 0.4 μm.
The following structure as a charge transport material:

を有するトリフェニルアミン化合物１００重量部、バインダ樹脂としてポリカーボネート樹脂（商品名：ＰＣＺ−４００、三菱ガス化学株式会社製）１５０重量部およびシリコンオイル０.０２重量部を混合し、テトラヒドロフランを溶剤として固形分２５重量％の電荷輸送層形成用塗布液（３ｋｇ）を調製した。

100 parts by weight of a triphenylamine compound having 150 parts by weight, polycarbonate resin (trade name: PCZ-400, manufactured by Mitsubishi Gas Chemical Co., Ltd.) 150 parts by weight and silicon oil 0.02 parts by weight are mixed, and tetrahydrofuran is used as a solvent to form a solid A coating solution (3 kg) for forming a charge transport layer having a weight of 25% by weight was prepared.

The obtained charge transport layer forming coating solution was applied to the surface of the charge generation layer previously provided in the same manner as in the intermediate layer formation, and dried at 130 ° C. for 1 hour to form a charge transport layer having a thickness of 25 μm. Formed.
In this way, the photoreceptor shown in FIG. 1 was produced.

Example 2
The coating solution for forming the intermediate layer obtained in the same manner as in Example 1 was filled in the coating tank, and an aluminum drum-shaped support having a diameter of 30 mm and a total length of 340 mm was immersed as a conductive support, and then the lifting speed was increased. The electrophotographic photosensitive member of Example 2 was produced in the same manner as in Example 1 except that it was naturally dried to form an intermediate layer having a thickness of 20 μm.

Example 3
An electrophotographic photosensitive member of Example 3 was produced in the same manner as in Example 1 except that 8 parts by weight of the trade name Lucentite SEN (manufactured by Co-op Chemical) was used as the flat silicate.

Example 4
The product name Lucentite SAN (manufactured by Corp Chemical Co.), 8 parts by weight, which is a flat silicate, and a commercially available polyamide resin (trade name: Ultramid 1c, manufactured by BASF, 8 parts by weight, tetrahydrofuran 42 parts by weight, methyl In addition to 42 parts by weight of alcohol, an intermediate layer-forming coating solution (3 kg) was prepared by dispersing for 8 hours with a paint shaker, and the viscosity was 100 mPa · s.

Example 5
Production of the photoreceptor shown in FIG. 2 Product name Lucentite SPN (manufactured by Co-op Chemical) 8 parts by weight, conductive titanium oxide FT-1000 (manufactured by Ishihara Sangyo) 8 parts by weight and a commercially available polyamide resin (Product name: Ultramid 1c, manufactured by BASF, 8 parts by weight was added to 76 parts by weight of methyl alcohol and dispersed for 8 hours with a paint shaker to prepare a coating solution for forming an intermediate layer (3 kg). The viscosity was 150 mPa · s.

  The obtained coating solution for forming an intermediate layer is filled in a coating tank, and an aluminum drum-like support having a diameter of 30 mm and a total length of 340 mm is immersed as a conductive support, and then pulled up and dried naturally to form an intermediate layer having a thickness of 10 μm. Formed.

Next, as a polyamide resin, in addition to 8 parts by weight of alcohol-soluble copolymer nylon (trade name: Amilan CM8000, manufactured by Toray Industries, Inc.) and 92 parts by weight of methyl alcohol, a dispersion process is performed for 8 hours using a paint shaker, and the second intermediate layer. A forming coating solution (3 kg) was prepared.
A second intermediate layer shown in FIG. 3 having a thickness of 1 μm was formed by dip coating on the intermediate layer.
Thereafter, an electrophotographic photoreceptor of Example 5 was produced in the same manner as Example 1.

Example 6
An electrophotographic photoreceptor of Example 6 was produced in the same manner as in Example 1 except that the thickness of the intermediate layer was 1 μm.

Example 7
An electrophotographic photoreceptor shown in FIG. 1 was produced in the same manner as in Example 1 except that the surface of the aluminum conductive support was used without being cut.

Comparative Example 1
In preparation of the intermediate layer forming coating solution, alumina-treated titanium oxide particles (trade name: TTO-55A, manufactured by Ishihara Sangyo Co., Ltd., rutile type crystal, average primary particle diameter of 35 nm) are used as titanium oxide particles instead of flat silicate. The electrophotographic photoreceptor shown in FIG. 1 was produced in the same manner as in Example 1 except that it was used. The viscosity of the coating solution for forming an intermediate layer was 11 mPa · s.

Comparative Example 2
The electrophotographic photosensitive member shown in FIG. 3 was produced in the same manner as in Comparative Example 1 except that the thickness of the second intermediate layer was 1 μm.

Comparative Example 3
An electrophotographic photoreceptor shown in FIG. 3 was produced in the same manner as in Comparative Example 2 except that the surface of the aluminum conductive support was used without being cut.

Comparative Example 4
As a commercially available thickener, 1 part by weight of a trade name Metroze 65SH4000 (manufactured by Shin-Etsu Chemical Co., Ltd.), 8 parts by weight of conductive titanium oxide FT-1000 (manufactured by Ishihara Sangyo Co., Ltd.) and a commercially available polyamide resin (trade name: Ultramid) 1c (manufactured by BASF) was added to 83 parts by weight of methyl alcohol and dispersed for 8 hours with a paint shaker to prepare a coating solution for forming an intermediate layer (3 kg). The viscosity was 200 mPa · s.
In this state, dip coating is difficult due to high viscosity, so 42 parts by weight of methyl alcohol was added to adjust the viscosity to 20 mPa · s.

The obtained coating solution for forming an intermediate layer is filled in a coating tank, and an aluminum drum-shaped support body having a diameter of 30 mm and a total length of 340 mm is immersed as a conductive support body, and then pulled up and naturally dried to a film thickness of 10 μm. An intermediate layer was formed.
Thereafter, a charge generation layer and a charge transport layer were formed in the same manner as in Example 1 to produce the electrophotographic photoreceptor shown in FIG.
In addition, it was found that the coating liquid for forming the intermediate layer was very poor in stability because titanium oxide was precipitated in 2 days after the production.

The electrical characteristics and image characteristics of the photoreceptors of Examples 1 to 7 and Comparative Examples 1 to 4 manufactured as described above were evaluated.
Further, the coating property and coating solution stability of the coating solution for forming an intermediate layer used in the production of each photoreceptor were evaluated.

<Film thickness>
Using an eddy current film thickness meter (trade name: Fischerscope MMS-3AM, manufactured by Fischer Instruments Co., Ltd.), 2 cm from the upper end of the coating, 2 cm from the center, and 2 cm from the lower end were measured in the axial direction of the photoreceptor. The film thickness at the center was taken as the film thickness of the photoreceptor.

<Applicability>
The applicability was evaluated from the film thicknesses at the upper end and the lower end according to the following criteria.
G (good): Good Thickness difference is 2 μm or less B (bad): Bad Thickness difference is larger than 2 μm

<Electrical characteristics>
The light attenuation characteristics of each of the photoreceptors of Examples 1 to 7 and Comparative Examples 1 to 4 were measured.
Each photoconductor was mounted on a commercially available digital copying machine (manufactured by Sharp Corporation, model: AR-450S) equipped with a corona discharge charger as charging means for the photoconductor.

  After confirming the initial image, in order to measure the surface potential of the photoconductor in the image forming process, the developing unit is removed from the digital copying machine, and a surface potential meter (Model: MODEL344 manufactured by Trek Japan Co., Ltd.) is used instead. Installation, initial electrical properties and electrical durability were measured.

The surface of the photoreceptor when this digital copying machine is not exposed to laser light in a normal temperature / normal humidity (N / N) environment at a temperature of 25 ° C. and a relative humidity of 50%. The potential was measured as a charging potential V0 (−V), and the surface potential of the photosensitive member when exposed by laser light was measured as an exposure potential VL (−V).
Further, the surface potential of the photoconductor immediately after being exposed to the laser beam was measured as a residual potential Vr (−V). These measurement results were used as evaluation indexes for initial electrical characteristics.

<Image evaluation>
Next, the surface electrometer is removed from the digital copying machine, and the developing unit is attached again. For each photoconductor, the density of uneven density in the halftone image is adjusted to 80 gradations of 255 gradations by modulating the pulse width of the semiconductor laser. The presence or absence was observed. The criteria for determining density unevenness are as follows.
G (good): There is no density unevenness in the halftone image by visual inspection. Good picture.
NB (not bad): There is density unevenness in the halftone image visually. There is no problem in actual use.
B (bad): There is density unevenness in the halftone image visually. A level that causes problems in actual use.

  Next, a character test chart (ISO 19752) was printed (image formation) on 100,000 sheets of recording paper in an N / N environment.

  After image formation for 100,000 sheets was completed and image evaluation was performed in the same manner as in the initial stage, the developing device was removed from the digital copying machine, and a surface potential meter was attached again, and the charging potential V0 ( V) and exposure potential VL (V) were measured respectively.

Further, the surface potential of the photoconductor immediately after being exposed to the laser beam in the same manner as in the initial stage was measured as a residual potential Vr (−V).
It was evaluated that the smaller the potential fluctuation ΔVL (| V0−VL |), the better the stability of the electrical characteristics, and at the same time, the density and sharpness of the obtained character image were evaluated by visual observation.

The electrical characteristics were evaluated according to the following criteria.
VG (very good): very good ΔVL less than 30V.
G (good): Good ΔVL 30V or more and less than 65V.
NB (not bad): No problem in use ΔVL 65V or more and less than 80V.
B (bad): Bad ΔVL 80 V or more.

<Coating solution stability>
The viscosities of the coating solutions for forming the intermediate layer used in the production of the respective photoreceptors of Examples 1 to 7 and Comparative Examples 1 to 4 were measured using an E-type viscometer (manufactured by Toki Sangyo, RE-125L). The viscosity change value was determined immediately after preparation and after standing at room temperature for 90 days.

The coating solution stability of the coating solution for forming an intermediate layer was evaluated according to the following criteria.
VG (very good): very good Viscosity change value less than 1.
G (good): Good Viscosity change value 1 or more and less than 5.
NB (not bad): No change in viscosity Viscosity change value of 5 or more and less than 20.
B (bad): Bad Viscosity change value of 20 or more.

<Comprehensive evaluation>
The above applicability, coating solution stability, initial image characteristics, electrical characteristics, and post-use image characteristics were comprehensively evaluated.
G (good): Good All B (bad) None B (bad): Bad Even one item has B (bad)

Table 1 shows the results obtained in the above evaluation.

From the evaluation results in the above table, the following was found.
Conventionally, the intermediate layer has a thickness of about 1 μm (Comparative Example 2). This intermediate layer improves electrical characteristics by preventing the injection of charges from the conductive support, and prevents reflection of laser light on the surface of the conductive support. It is possible to prevent moiré from occurring.

However, if a non-cut conductive support is used instead of a cut conductive support due to cost reduction requirements, the reflected light on the support surface cannot be suppressed with an intermediate layer of only 1 μm, resulting in moiré. is doing. (Comparative Example 3)
Therefore, when the film thickness of the intermediate layer is increased to 10 μm, moire images can be prevented, but the wet coating solution drips until it dries, and the coating film becomes non-uniform. This also affects the image density. (Comparative Example 1)
In order to improve the dripping of the coating solution, a conventionally known thickener was used together with titanium oxide as in Comparative Example 4, but the coating solution could not be optimized and a uniform coating film could not be realized. It was.

On the other hand, the electrophotographic photosensitive member (Example 1) using the flat silicate of the present invention can be applied uniformly without causing dripping even at a film thickness of 10 μm. Even on a non-cutting support, it is possible to realize a good image with no moire. (Example 7)
This shows that the coating liquid which does not sag due to the thickening effect of the coating liquid by the plate-like silicate can be realized.

Further, it is possible to make the intermediate layer thicker (Example 2). It is also possible to make the intermediate layer into two layers (Example 5).
Moreover, the coating solution for forming an intermediate layer of the present invention is excellent in storage stability despite being high in viscosity, and maintains a good dispersed state even after standing for 90 days.

Also, the electrical characteristics show the same performance as that of the prior art.
From the above, the electrophotographic photosensitive member of the present invention can provide an electrophotographic photosensitive member capable of realizing good image characteristics without coating unevenness and an image forming apparatus including the same.

  Further, the coating solution used for coating and forming the intermediate layer of the photoreceptor of the present invention can maintain a desired dispersion state for a long period of time.

  The inorganic layered silicate compound (tabular silicate) contained in the intermediate layer of the electrophotographic photoreceptor according to the present invention has a large thickening effect even in a small amount, facilitates the adjustment of the viscosity of the coating solution, and is excellent without coating unevenness. It is possible to realize image characteristics, and when manufacturing a photoreceptor using an inexpensive uncut tube as a material, by laminating the intermediate layer on a conductive support, there is no uneven coating due to the unevenness of the tube. Image characteristics can be realized.

1 Stacked type photoconductor (photoconductor)
10, 20, 26 Electrophotographic photosensitive member 11, 21, 27 Charge transport layer 12, 22, 28 Charge generation layer 23 Second intermediate layer 14, 24, 29 Intermediate layer 15, 25, 30 Conductive support 31 Exposure means (exposure means) Semiconductor laser)
32 Charging means (charger)
33 Developing means (developer)
33a Developing roller 33b Casing 34 Transfer means (transfer charger)
35 Fixing means (fixing device)
35a Heating roller 35b Pressure roller 36 Cleaning means (cleaner)
36a Cleaning blade 36b Recovery casing 37 Separating means 38 Housing (casing)
41, 42 Arrow 44 Rotating axis 51 Transfer paper 100 Electrophotographic apparatus (laser printer)

Claims (10)

  An electrophotographic photoreceptor comprising an intermediate layer between a conductive support and a photosensitive layer, wherein the intermediate layer contains at least an inorganic layered silicate compound.   The electrophotographic photosensitive member according to claim 1, wherein the inorganic layered silicate compound is smectite.   The electrophotographic photosensitive member according to claim 1, wherein the inorganic layered silicate compound is a synthetic smectite.   The electrophotographic photosensitive member according to claim 1, wherein the inorganic layered silicate compound is a plate-like silicate.   The electrophotographic photosensitive member according to claim 1, wherein the inorganic layered silicate compound is a powder having a number average particle diameter of 0.1 μm to 2 μm.   The electrophotographic photosensitive member according to claim 1, wherein the inorganic layered silicate compound is contained in an amount of 50 wt% to 200 wt% with respect to the binder resin.   The electrophotographic photosensitive member according to claim 1, wherein the intermediate layer has a thickness of 10 μm to 20 μm.   The electrophotographic photosensitive member according to claim 1, wherein the intermediate layer has at least a two-layer structure.   The electrophotographic photosensitive member according to claim 1, wherein the electrophotographic photosensitive member is constituted by a non-cutting support.   9. The electrophotographic photosensitive member according to claim 1; a charging unit that charges the electrophotographic photosensitive member; and the charged electrophotographic photosensitive member is exposed to form an electrostatic latent image. An exposure unit, a development unit that develops and visualizes the electrostatic latent image formed by the exposure, and a transfer unit that transfers the image visualized by the development onto a recording medium. An image forming apparatus.

Images