JP2001290294A - Electrophotographic photoreceptor, electrophotographic method, electrophotographic device and process cartridge for electrophotographic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor which is electrostatically stable, has high surface lubricity and is less liable to wear even after repeated use, an electrophotographic method, an electrophotographic device and a process cartridge for the device. SOLUTION: The electrophotographic photoreceptor has a layer containing a fatty acid of the formula CmH2m+1COOH (where (m) is an integer of 10-31) or the formula HOOC(CH2)nCOOH (where (n) is an integer of 10-32). The electrophotographic device has the photoreceptor and also has at least an electrifying means, an imagewise exposing means, a developing means, a transferring means, a cleaning means and a de-electrifying means around the photoreceptor. The process cartridge has the photoreceptor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photosensitive member (in the present invention, it may be simply referred to as a photosensitive member),
The present invention relates to an electrophotographic method, an electrophotographic apparatus, and a process cartridge for an electrophotographic apparatus. More specifically, an electrophotographic photoreceptor that is electrostatically stable even when repeatedly used, has high surface lubricity and is hardly worn, and using this photoreceptor The present invention relates to an electrophotographic method, an electrophotographic apparatus, and a process cartridge for an electrophotographic apparatus capable of obtaining a stable image with few abnormal images.

[0002]

2. Description of the Related Art In recent years, there has been a remarkable progress in the development of information processing systems using an electrophotographic system. In particular, optical printers that convert information into digital signals and record information with light have significantly improved print quality and reliability. This digital recording technique is applied not only to printers but also to ordinary copying machines, and so-called digital copying machines have been developed. Further, since a copier equipped with this digital recording technology is added to a conventional analog copier with various information processing functions, its demand is expected to increase further in the future. On the other hand, in the Carlson process and similar processes, the electrophotographic photoreceptor that is repeatedly used has excellent electrostatic characteristics such as sensitivity, accepting potential, potential holding property, potential stability, residual potential, and spectral characteristics. Is required. In recent years, high resolution has been desired in terms of image quality, and for this reason, a thinner photoreceptor film thickness has been required. It has become.

[0003] The applicant of the present invention has previously described an electrophotographic photoreceptor in which a photosensitive layer containing at least a charge generating substance and a charge transporting substance in the same or different layers is provided on a conductive support. , A pH buffer having both an acid having a pKa of 7.0 or less and a conjugate base thereof, whereby an electrophotographic photosensitive material having electrostatic stability is maintained. (Japanese Unexamined Patent Publication No. 07-191)
No. 477). However, the pH buffer used here is inferior in compatibility with the resin for the charge transport layer, and when added in a large amount, has a drawback of separation and crystallization in the layer. It is also known that the outermost surface layer of the photoreceptor contains abrasion-resistant particles, for example, metal oxide particles, for improving the abrasion resistance. However, when metal oxide particles are contained, the residual potential increases, or the chargeability decreases,
There is a drawback that electrostatic fatigue is significantly increased. Further, it has been proposed that a fatty acid metal salt be contained in the surface layer of the photoreceptor (Japanese Patent No. 2746299 and Japanese Patent Application Laid-Open No.
181299). This intends the effect of the fatty acid portion as a lubricant. However, the effect of the abrasion resistance is small using only the fatty acid metal salt, and a hard material such as a metal oxide is required to improve the abrasion resistance. However, the use of fatty acid metal salts and metal oxides has the disadvantage of increasing the residual potential.

[0004]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional disadvantages, and provides an electrophotographic photosensitive member which is electrostatically stable even after repeated use, has a high surface lubricity and is hardly worn.
An object of the present invention is to provide an electrophotographic method, an electrophotographic apparatus, and a process cartridge for an electrophotographic apparatus capable of obtaining a stable image with less abnormal images using the photoconductor.

[0005]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, by forming a layer containing a long-chain fatty acid on an electroconductive support,
An electrophotographic photoreceptor that is electrostatically stable even after repeated use, has high surface lubricity, and is hardly worn away. By using this photoreceptor, it is possible to obtain a stable image with less abnormal images. It has been found that an electrophotographic method, an electrophotographic apparatus, and a process cartridge for an electrophotographic apparatus can be obtained, and the present invention has been completed based on this finding. That is, according to the present invention, conductive on a support, at least the following general formula (1) or the electrophotographic photosensitive member, characterized in that to form a layer containing a fatty acid represented by (2), C _m H _{2m + 1} COOH (1) (m represents an integer of 10 to 31) HOOC (CH ₂ ) _n COOH (2) (n represents an integer of 10 to 32) At least charging, image exposure, development,
An electrophotographic method for repeatedly performing transfer, cleaning and static elimination, wherein the electrophotographic photoreceptor is used, wherein at least a charging unit, an image exposing unit, a developing unit, and a transfer unit are provided on the electrophotographic photoreceptor. An electrophotographic apparatus having a cleaning unit and a static elimination unit, wherein the electrophotographic apparatus includes the electrophotographic photosensitive member, and a process cartridge for the electrophotographic apparatus having at least the electrophotographic photosensitive member, Provided is a process cartridge for an electrophotographic apparatus, which is provided with an electrophotographic photosensitive member.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, first, at least a fatty acid represented by the following general formula (1) or (2) (hereinafter, sometimes referred to as a long-chain fatty acid) is contained on an electrically conductive support. An electrophotographic photoreceptor characterized by having a layer formed thereon. C _m H _{2m + 1} COOH (1) (m represents an integer of 10 to 31.) HOOC (CH ₂ ) _n COOH (2) (n represents an integer of 10 to 32.)

The electrophotographic photosensitive member of the present invention will be described with reference to the drawings. FIG. 1 is a schematic sectional view showing the electrophotographic photosensitive member of the present invention. This electrophotographic photoreceptor comprises a conductive support 1 on which a single-layer photosensitive layer 2 mainly composed of a charge generating substance and a charge transporting substance is provided. This single-layer photosensitive layer 2
The long-chain fatty acid is contained therein. FIG. 2 is a schematic sectional view showing another electrophotographic photosensitive member of the present invention. This electrophotographic photoreceptor has a configuration in which a charge generation layer 2 ′ mainly composed of a charge generation substance and a charge transport layer 2 ″ mainly composed of a charge transport substance are laminated on a conductive support 1. The long-chain fatty acid is contained in the charge transport layer 2 ″. FIG. 3 is a schematic sectional view showing another electrophotographic photosensitive member of the present invention. This electrophotographic photoreceptor comprises a conductive support 1 on which a single-layer photosensitive layer 2 mainly composed of a charge generating substance and a charge transporting substance is provided, and a protective layer 3 is provided thereon. The protective layer 3 contains the long-chain fatty acid. FIG. 4 is a schematic sectional view showing still another electrophotographic photosensitive member of the present invention. This electrophotographic photoreceptor has a configuration in which a charge generation layer 2 ′ mainly composed of a charge generation substance and a charge transport layer 2 ″ mainly composed of a charge transport substance are laminated on a conductive support 1. And the protective layer 3 is provided thereon.The charge transport layer 2 "and / or the protective layer 3 contain the long-chain fatty acid. FIG. 5 is a schematic sectional view showing still another electrophotographic photoreceptor of the present invention. This electrophotographic photoreceptor is obtained by reversing the charge generation layer 2 ′ and the charge transport layer 2 ″ in the electrophotographic photoreceptor in FIG. 4. The charge transport layer 2 ″ and / or
Alternatively, the long-chain fatty acid is contained in the protective layer 3. These photographic photoreceptors may be provided with an undercoat layer below the photosensitive layer.

Here, a case where a long-chain fatty acid is contained in the protective layer 3 will be described. As the conductive support 1, one having a conductivity of 10 ¹⁰ Ω · cm or less,
For example, aluminum, nickel, chromium, nichrome,
Copper, gold, silver, metals such as platinum, tin oxide, metal oxides such as indium oxide, by vapor deposition or sputtering, coated on film or cylindrical plastic, paper or aluminum, aluminum alloy, nickel,
A plate made of stainless steel or the like, or a tube or the like that has been subjected to surface treatment such as cutting, superfinishing, or polishing after being formed into a tube by a method such as extrusion or drawing can be used. Further, an endless nickel belt and an endless stainless belt disclosed in JP-A-52-36016 can also be used. In addition, those obtained by dispersing a conductive powder in a suitable binder resin on the above support and applying the same can also be used as the conductive support 1 of the present invention.

As the conductive powder, carbon black, acetylene black or aluminum, nickel,
Metal powders such as iron, nichrome, copper, zinc, and silver, and metal oxide powders such as conductive tin oxide and ITO may be used. Examples of the binder resin used include polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, and polyacetic acid. Vinyl, polyvinylidene chloride, polyarylate resin, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly-N-vinyl carbazole, acrylic resin, silicone resin, epoxy resin, melamine resin And a thermoplastic resin such as a urethane resin, a phenol resin, and an alkyd resin, a thermosetting resin, or a photocurable resin.

Such a conductive layer can be provided by dispersing the conductive powder and the binder resin in an appropriate solvent, for example, tetrahydrofuran, dichloromethane, methyl ethyl ketone, toluene, or the like, and applying the dispersion. In addition, a heat-shrinkable tube in which the above-mentioned conductive powder is contained in a material such as polyvinyl chloride, polypropylene, polyester, polystyrene, polyvinylidene chloride, polyethylene, chloride rubber, and Teflon (registered trademark) on a suitable cylindrical substrate. A conductive layer provided with a conductive layer is also suitable as the conductive support 1 of the present invention.

Next, the photosensitive layer will be described. The charge generating layer 2 'is formed by dispersing a charge generating material together with a binder resin as necessary in a suitable solvent using a ball mill, an attritor, a sand mill, ultrasonic waves, or the like.
It is formed by coating on top and drying. As the binder resin used as necessary, polyamide, polyurethane, epoxy resin, polyketone, polycarbonate, silicone resin, acrylic resin, polyvinyl butyral, polyvinyl formal, polyvinyl ketone, polystyrene, poly-N-vinyl carbazole, polyacrylamide, Examples include polyvinyl benzal, polyester, phenoxy resin, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyphenylene oxide, polyamide, polyvinyl pyridine, cellulose resin, casein, polyvinyl alcohol, polyvinyl pyrrolidone, and the like.
Above all, polyvinyl acetal represented by polyvinyl butyral is preferable. The amount of the binder resin is 0 to 500 parts, preferably 10 to 300 parts, based on 100 parts of the charge generating substance on a weight basis.

The charge generating material used in the charge generating layer 2 'includes monoazo pigments, disazo pigments, trisazo pigments, perylene pigments, perinone pigments, quinacridone pigments, quinone condensed polycyclic compounds, squaric acid dyes, Examples include phthalocyanine-based pigments, na-based condensed polycyclic compounds, squaric acid-based dyes, phthalocyanine-based pigments, naphthalocyanine-based pigments, and azurenium salt-based dyes.

The solvents used herein include isopropanol, acetone, methyl ethyl ketone, cyclohexanone, tetrahydrofuran, dioxane, ethyl cellosolve, ethyl acetate, methyl acetate, dichloromethane, dichloroethane, monochlorobenzene, cyclohexane,
Toluene, xylene, ligroin and the like can be mentioned, with ketone solvents, ester solvents and ether solvents being particularly preferred. As a method of applying the coating liquid, a method such as a dip coating method, a spray coat, a beat coat, a nozzle coat, a spinner coat, and a ring coat can be adopted. The thickness of the charge generation layer 2 ′ is usually 0.01 to 5 μm.
m, and preferably 0.1 to 2 μm.

The charge transporting layer 2 "can be formed by dissolving or dispersing the charge transporting substance and the binder resin in a suitable solvent, applying this on the charge generating layer and drying it. Additives, leveling agents, antioxidants, etc. The charge transport materials include hole transport materials and charge transport materials, such as poly-N-vinyl carbazole and its derivatives. , Poly-γ
-Carbazolylethyl glutamate and its derivatives, pyrene-formaldehyde condensate and its derivatives, polyvinylpyrene, polyvinylphenanthrene, polysilane,
Oxazole derivative, oxadiazole derivative, imidazole derivative, monoarylamine derivative, diarylamine derivative, triarylamine derivative, stilbene derivative, α-phenylstilbene derivative, benzidine derivative, diarylmethane derivative, triarylmethane derivative, 9-styrylanthracene Known substances such as derivatives, pyrazoline derivatives, divinylbenzene derivatives, hydrazone derivatives, indene derivatives, butadiene derivatives, pyrene derivatives and the like, bisstilbene derivatives, enamine derivatives and the like can be mentioned. These charge transport materials may be used alone or in combination of two or more.

Examples of the charge transport material include chloranil, bromoanil, tetracyanoethylene, tetracyanoquinodimethane, 2,4,7-trinitro-9-fluorenone, 2,4,5,7-tetranitro-9-fluorenone. 2,4,5,7-tetranitroxanthone,
2,4,8-trinitrothioxanthone, 2,6,8-
Examples thereof include electron accepting substances such as trinitro-4H-indeno [1,2-b] thiophen-4-one, 1,3,7-trinitrodibenzothiophene-5,5-dioxide, and benzoquinone derivatives.

Examples of the binder resin include polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, and polystyrene. Vinyl acetate, polyvinylidene chloride, polyalate, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly-N-vinyl carbazole, acrylic resin, silicone resin, epoxy resin, melamine resin, urethane Thermoplastic resins or thermosetting resins such as resins, phenolic resins and alkyd resins are exemplified. The amount of the charge transporting substance is usually 20 to 300 based on 100 parts by weight of the binder resin.
Parts, preferably 40 to 150 parts. In order to obtain high resolution, the thickness of the charge transport layer 2 ″ is 5 to 20
It is preferable that the thickness be about μm. Examples of the solvent used here include tetrahydrofuran, dioxane, toluene, dichloromethane, monochlorobenzene, dichloroethane, cyclohexanone, methyl ethyl ketone, acetone and the like.

In the photoreceptor of the present invention, a plasticizer or a leveling agent may be added to the charge transport layer 2 ". The plasticizer is used as a plasticizer for general resins such as dibutyl phthalate and dioctyl phthalate. Can be used, and the amount used is 0 to binder resin on a weight basis.
About 30% is appropriate. Examples of the leveling agent include silicone oils such as dimethyl silicone oil and methyl phenyl silicone oil, and polymers or oligomers having a perfluoroalkyl group in a side chain. On the other hand, 0
1% is appropriate.

Next, the protective layer 3 will be described. The main component of the protective layer 3 is a binder resin, and the same binder resin as that used in the charge transport layer 2 'is used. In addition, the protective layer 3 may contain a charge transport material.
The protective layer 3 contains a long-chain fatty acid which is a feature of the present invention. The long-chain fatty acid may be simultaneously contained in the charge transport layer 2 ″. Here, the long-chain fatty acid refers to a fatty acid represented by the following general formula (1) or (2): C _m H _{2m +1} COOH (1) (m represents an integer of 10 to 31) HOOC (CH ₂ ) _n COOH (2) (n represents an integer of 10 to 32) As represented by the formula (1) or (2), it has a relatively large molecular weight because it makes it difficult to move in the photoreceptor. Further, it is preferably a weak acid, preferably non-volatile, soluble in the solvent used for the coating liquid, and low in water absorption (solubility in water).

Examples of such long-chain fatty acids include n-undecylenic acid, lauric acid, n-tridecylenic acid, myristic acid, n-pentadecylenic acid, palmitic acid, margaric acid, stearic acid, n-nonadesilenic acid, arachidic acid, n-Henaicosanoic acid, behenic acid, n-tricosanoic acid, ligonoceric acid, n-pentacosanoic acid, cerotic acid, n-heptacosanoic acid, montanic acid, n-nonacosanoic acid, melisic acid, n-hentriacontanic acid, n- Dotriacontanic acid, dodecane diacid, tridecane diacid, tetradecane diacid, pentadecane diacid, hexadecane 2
Acid, heptadecane diacid, octadecane diacid, nonadecane diacid, eicosane diacid, tricosan diacid, tetracosane diacid, hexacosane diacid, triacontan diacid, tetratricontan diacid, and the like. Stearic acid is a particularly suitable long-chain fatty acid in view of its compatibility with and its effect as an acid. Then, it is desirable that the material has high purity, particularly, the purity is 95% or more. The content of this long-chain fatty acid is usually 0.1 to 40%, preferably 0.5 to 40% based on the weight of the protective layer 3.
30%. If the content of the long-chain fatty acid is less than 0.1%, the effect of improving the electrostatic properties is low, and if it exceeds 40%, the compatibility with the resin is deteriorated and a uniform film may not be obtained.

The protective layer 3 may contain, as wear-resistant particles, fluororesins such as polytetrafluoroethylene, silicone resins, organic polymer particles, and metal oxide particles. Examples of the metal oxide include titanium oxide, aluminum oxide, silicon oxide, tin oxide, iron oxide, and zirconium oxide. The particle size of these particles is preferably 0.5 μm or less to prevent light scattering. The amount of addition
In order to ensure electrostatic stability, the content is 0.1 to 30% based on the total solid content in the protective layer 3 on a weight basis.

The binder resin used for the protective layer 3 includes
ABS resin, ACS resin, olefin-vinyl monomer copolymer, chlorinated polyether, allyl resin, phenol resin, polyacetal, polyamide, polyamideimide, polyacrylate, polyallylsulfone, polybutylene, polybutylene terephthalate, polycarbonate, polyethersulfone , Polyethylene, polyethylene terephthalate, polyimide, acrylic resin, polymethylbenthene, polypropylene, polyphenylene oxide, polysulfone, polystyrene, AS resin, butadiene-styrene copolymer, polyurethane, polyvinyl chloride, polyvinylidene chloride, epoxy resin, etc. Can be. As a method for forming the protective layer 3, a normal coating method is adopted, and when the solvent dissolves the lower layer, a spray coating method is preferable. The thickness of the protective layer 3 is 0.1 to
About 10 μm is appropriate.

The case where the long-chain fatty acid is contained in the charge transport layer 2 ′ is not particularly different from the case where the long-chain fatty acid is contained in the protective layer 3. However, the content of long-chain fatty acids is 0.1 to 15
% Is preferable. Long chain fatty acid content is 15%
If the ratio exceeds the above range, the adhesion between the electrode and the photoreceptor deteriorates.

Next, the present invention provides an electrophotographic method for repeating at least charging, image exposure, development, transfer, cleaning and charge elimination on an electrophotographic photosensitive member, wherein the electrophotographic photosensitive member is used. An electrophotographic apparatus having at least a charging unit, an image exposing unit, a developing unit, a transferring unit, a cleaning unit, and a discharging unit, which is provided with the electrophotographic photosensitive member described above. An electrophotographic apparatus is provided. An electrophotographic method and an electrophotographic apparatus according to the present invention will be described with reference to the drawings. FIG. 6 is a schematic view showing the electrophotographic method and the electrophotographic apparatus of the present invention. As the photoconductor 4, the above-described electrophotographic photoconductor of the present invention is used. The photoconductor 4 has a drum shape, but may have a sheet shape or an endless belt shape. Charging charger 5, pre-transfer charger 6, transfer charger 7, separation charger 8,
Known means such as a corotron, a scorotron, a solid state charger (solid state charger), and a charging roller are used for the pre-cleaning charger 9. As the transfer means, the above-described charger can be generally used, but as shown in the figure, a combination of the transfer charger 7 and the separation charger 8 is effective. The light source such as the image exposure unit 10 and the static elimination lamp 11 includes a fluorescent lamp,
A general light emitting material such as a tungsten lamp, a halogen lamp, a mercury lamp, a sodium lamp, a light emitting diode (LED), a semiconductor laser (LD), and an electroluminescence (EL) can be used. And in order to irradiate only the light of the desired wavelength range, a sharp cut filter,
Various filters such as a band-pass filter, a near-infrared cut filter, a dichroic filter, an interference filter, and a color temperature conversion filter can also be used.
Such a light source or the like irradiates the photoreceptor with light through a process such as a transfer process using light irradiation, a charge removal process, a cleaning process, or a pre-exposure process in addition to the process shown in FIG. Here, the toner developed on the photoconductor 4 by the developing unit 12 is transferred to the transfer paper 13, but not all of the toner is transferred, and some toner remains on the photoconductor 4. This residual toner is removed from the photoconductor 4 by the fur brush 14 and the cleaning brush 15. Cleaning may be performed only with the cleaning brush 15. Known brushes such as a fur brush and a mag fur brush are used as the cleaning brush.

When a positive (negative) charge is applied to the electrophotographic photosensitive member and image exposure is performed, a positive (negative) electrostatic latent image is formed on the surface of the photosensitive member. This is called negative (positive) polarity toner (electrostatic fine particles)
And a positive (negative) polarity toner, a negative image can be obtained. A well-known method is applied to such a developing unit, and a well-known method is also used for the static elimination unit.

FIG. 7 is a schematic view showing another electrophotographic method and electrophotographic apparatus of the present invention. As the photoconductor 4, the above-described electrophotographic photoconductor of the present invention is used. The photoconductor 4 is
Driven by the drive rollers 19a and 19b, charging by the charging charger 5, image exposure by the image exposure source 20, development (not shown), transfer using the transfer charger 7, exposure before cleaning by the exposure source 21 before cleaning, cleaning brush 15 , And static elimination is repeatedly performed by the static elimination light source 22. In the photoreceptor shown in FIG. 5, the photoreceptor 4 (in this case, the support is translucent) is irradiated with light for pre-cleaning exposure from the support side.

The electrophotographic method and the electrophotographic apparatus illustrated above are one embodiment of the present invention, and other embodiments can be adopted. For example, in FIG. 7, the pre-cleaning exposure is performed from the support side, but this may be performed from the photosensitive layer side.
Irradiation with static elimination light may be performed from the support side. In the light irradiation step, image exposure, pre-cleaning exposure, and charge removal exposure are illustrated, but in addition, pre-transfer exposure, pre-exposure of image exposure and other known light irradiation steps are provided, and the photosensitive member is exposed to light. Irradiation can also be performed.

The present invention further provides a process cartridge for an electrophotographic apparatus having at least an electrophotographic photosensitive member, wherein the process cartridge for an electrophotographic apparatus is provided with the above electrophotographic photosensitive member. is there. The image forming means described so far includes a copying apparatus,
It may be fixed and incorporated in a facsimile or a printer, or may be incorporated in these devices in the form of a process cartridge and made detachable.
A process cartridge is one device (part) that includes a photoconductor, and further includes a charging unit, an exposure unit, a developing unit, a transfer unit, a cleaning unit, and a discharging unit. FIG.
1 is a schematic view showing an example of a process cartridge for an electrophotographic apparatus according to the present invention. As the photoconductor 4, the above-described electrophotographic photoconductor of the present invention is used. There are many types of process cartridges and the like, but the one shown in FIG. 8 is an example of a general process cartridge.

[0028]

(Undercoat layer coating liquid)

 Titanium dioxide powder 15 parts Alkyd resin liquid 4.5 parts (solid content 3 parts) Melamine liquid 2.5 parts (solid content 1.6 parts) 2-butanone 67 parts [Coating liquid for charge generating layer] titanyl phthalocyanine powder 5 parts Polyvinyl butyral 1 part Tetrahydrofuran 90 parts [Coating solution for charge transport layer] Polycarbonate 10 parts Charge transport material of the following structural formula 8 parts

Embedded image Tetrahydrofuran 80 parts Silicon oil 0.0004 parts The thickness of the undercoat layer was about 3.5 μm, the thickness of the charge generation layer was about 0.5 μm, and the thickness of the charge transport layer was about 13 μm.
A protective layer solution having the following composition was applied thereon to form a protective layer, thereby producing an electrophotographic photosensitive member. [Protective layer coating solution] 25 parts of polycarbonate 25 parts of a charge transport material having the following structural formula

Embedded image Aluminum oxide powder 10 parts Tetrahydrofuran 250 parts Stearic acid 10 parts

Example 2 An electrophotographic photosensitive member was produced in the same manner as in Example 1, except that the composition of the protective layer in Example 1 was changed as follows. [Protective layer coating solution] 25 parts of polycarbonate 25 parts of a charge transport material having the following structural formula

Embedded image Titanium oxide (TTO55N manufactured by Ishihara Sangyo Co., Ltd.) 5 parts Tetrahydrofuran 250 parts Stearic acid 10 parts

Comparative Example 1 An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that stearic acid was not used.

Example 3 An electrophotographic photosensitive member was produced in the same manner as in Example 1, except that the protective layer was not formed and the composition of the charge transport layer was as follows. [Charge transport layer coating solution] Polycarbonate 25 parts Charge transport material of the following structural formula 25 parts

Embedded image Trahydrofuran 250 parts Stearic acid 5 parts

Comparative Example 2 An electrophotographic photosensitive member was prepared in the same manner as in Example 3, except that stearic acid was not used for the charge transport layer.

[Evaluation] In order to examine the sensitivity of the laminated electrophotographic photosensitive member thus produced, the photosensitive member was subjected to -6 kv in a dark place using an electrostatic copying paper tester (manufactured by Kawaguchi Electric Works). Was charged (potential Vm (V)) for 20 seconds, and further left in a dark place for 20 seconds, and then the surface potential V ₀ (V) was measured. Then, 780n
m monochromatic light was irradiated onto the surface of the photoreceptor at an amount of 5 μW / cm ^2, and the exposure E1 / 2 (uJ / cm ² ) from -800 volts until the potential became １ ／ was calculated. Furthermore, the potential [residual potential V ₃₀ (V)] 30 seconds after the exposure was measured. Further, the amount of white light and the amount of charge were adjusted so that a current of 0.29 μA / cm ² flows while the photoconductor was maintained at -800 V, and the photoconductor was fatigued continuously for 15 minutes. Table 1 shows the results.

[Table 1]

Table 1 shows that Comparative Example 1 in which stearic acid was not added had a higher residual potential, while Example 1 in which stearic acid was added had a lower residual potential.
Further, even when the protective layer was not formed, as shown in Example 3, it was found that the addition of stearic acid to the charge transport layer reduced the residual potential as compared with Comparative Example 2. Further, as seen in Examples 1 and 2, it is clear that the provision of the protective layer containing the metal oxide improves the abrasion resistance, and the thickness of the charge transport layer and the protective layer is improved. Was set to 20 μm or less, a high-resolution image could be obtained. The stearic acid used had a purity of 95% or more. This purity is 95
%, The chargeability is inferior.

[0035]

According to the present invention, an electrophotographic photosensitive member which is electrostatically stable even when repeatedly used, has a high surface lubricity and is hardly worn, and has few abnormal images using the photosensitive member,
Moreover, an electrophotographic method that can obtain a stable image,
An electrophotographic apparatus and a process cartridge for the electrophotographic apparatus are provided, and greatly contribute to the design and manufacturing fields of a copying apparatus, a facsimile, a printer, and the like.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing an electrophotographic photoreceptor of the present invention.

FIG. 2 is a schematic sectional view showing another electrophotographic photosensitive member of the present invention.

FIG. 3 is a schematic sectional view showing another electrophotographic photosensitive member of the present invention.

FIG. 4 is a schematic sectional view showing still another electrophotographic photosensitive member of the present invention.

FIG. 5 is a schematic sectional view showing still another electrophotographic photosensitive member of the present invention.

FIG. 6 is a schematic view showing an electrophotographic method and an electrophotographic apparatus of the present invention.

FIG. 7 is a schematic view showing another electrophotographic method and an electrophotographic apparatus according to the present invention.

FIG. 8 is a schematic view illustrating an example of a process cartridge for an electrophotographic apparatus according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Conductive support 2 Photosensitive layer 2 'Charge generation layer 2 "Charge transport layer 3 Protective layer 4 Photoconductor 5 Charging charger 6 Charger before transfer 7 Transfer charger 8 Separation charger 9 Charger before cleaning 10 Image exposure part 11 Static removal lamp 12 Development Unit 13 Transfer paper 14 Fur brush 15 Cleaning brush 16 Eraser 17 Registration roller 18 Separation claw 19a Drive roller 19b Drive roller 20 Image exposure source 21 Exposure source before cleaning 22 Static elimination light source 23 Developing roller

Claims (13)

[Claims] 1. An electrophotographic photoreceptor comprising a layer containing at least a fatty acid represented by the following general formula (1) or (2) formed on an electroconductive support. C _m H _{2m + 1} COOH (1) (m represents an integer of 10 to 31.) HOOC (CH ₂ ) _n COOH (2) (n represents an integer of 10 to 32.) 2. The electrophotographic photosensitive member according to claim 1, wherein the fatty acid-containing layer is a charge transport layer in an electrophotographic photosensitive member having at least a photosensitive layer comprising a charge generation layer and a charge transport layer. 3. The electrophotographic photoreceptor according to claim 1, wherein the fatty acid-containing layer is a protective layer in an electrophotographic photoreceptor having at least a protective layer formed on a photosensitive layer. 4. The electrophotographic photoreceptor according to claim 3, wherein the protective layer contains a metal oxide and a charge transport material. 5. The electrophotographic photoreceptor according to claim 1, wherein said fatty acid is stearic acid. 6. The electrophotographic photoreceptor according to claim 5, wherein the stearic acid has a purity of 95% or more. 7. The electrophotographic photoreceptor according to claim 4, wherein said metal oxide is titanium oxide or aluminum oxide. 8. The electrophotographic photosensitive member according to claim 1, wherein the content of the fatty acid is 0.1 to 30% by weight based on the protective layer. 9. The electrophotographic photosensitive member according to claim 4, wherein the content of said metal oxide is 5 to 30% by weight based on the protective layer. 10. The electrophotographic photosensitive member according to claim 1, wherein said photosensitive layer has a thickness of 20 μm or less. 11. An electrophotographic photosensitive member comprising:
An electrophotographic method in which image exposure, development, transfer, cleaning, and charge elimination are repeatedly performed, wherein the electrophotographic photoreceptor according to claim 1 is used. 12. An electrophotographic apparatus comprising an electrophotographic photoreceptor having at least a charging unit, an image exposing unit, a developing unit, a transferring unit, a cleaning unit and a discharging unit. An electrophotographic apparatus comprising an electrophotographic photosensitive member. 13. A process cartridge for an electrophotographic apparatus having at least an electrophotographic photosensitive member, wherein the process cartridge has at least an electrophotographic photosensitive member.
A process cartridge for an electrophotographic apparatus, comprising the electrophotographic photosensitive member according to any one of claims 10 to 10.