JP4763728B2 - Electrophotographic photosensitive member, electrophotographic method, electrophotographic apparatus, process cartridge for electrophotographic apparatus, long-chain alkyl group-containing bisphenol compound and polymer using the same - Google Patents

Description

  The present invention relates to an electrophotographic photosensitive member, an electrophotographic method, an electrophotographic apparatus, and a process cartridge for an electrophotographic apparatus. More specifically, the invention maintains excellent image quality, and has excellent durability without potential fluctuation even when used repeatedly. The present invention relates to a high-sensitivity electrophotographic photosensitive member, an electrophotographic method using the electrophotographic photosensitive member, an electrophotographic apparatus having the electrophotographic photosensitive member, and a process cartridge used in the electrophotographic apparatus. The present invention also relates to a novel bisphenol compound containing a long-chain alkyl group and a polymer using the same.

  In general, in electrophotographic image formation, the surface of an electrophotographic photosensitive member (hereinafter sometimes referred to simply as a photosensitive member) is first charged in a dark place, for example, by corona discharge, and then image-exposed, and only the exposed portion is exposed. An electrostatic latent image is obtained by selectively dissipating electric charge, and the latent image portion is developed with a toner composed of a colorant such as a dye or a pigment and a polymer material, and the toner image is transferred onto a transfer material. It is carried out by a so-called Carlson process in which an image is formed by fixing, and toner remaining on the photoreceptor after transfer is cleaned and discharged for repeated use over a long period of time.

  Conventionally, inorganic photoconductors and organic photoconductors are generally known as photoconductors of the above-described photoreceptor. Photoconductors using organic photoconductors are usually more sensitive to photosensitive wavelength range, film formability, flexibility, film transparency, mass productivity, toxicity and cost compared to photoconductors using inorganic photoconductors. Since there are advantages in terms of surface and the like, an organic photoconductor is used in most photoconductors.

  In addition, a photoreceptor that is repeatedly used in an electrophotographic system and a similar system has excellent electrostatic characteristics such as sensitivity, receptive potential, potential retention, potential stability, residual potential, and spectral sensitivity characteristics. In addition to being present, properties such as printing durability, abrasion resistance, and moisture resistance during repeated use are also required to be good.

  In recent years, the development of information processing system machines using electrophotographic methods has been remarkable, especially in printers using digital recording methods that record information by light by converting information into digital signals, the print quality, Significant improvement in reliability.

  This digital recording system is applied not only to printers but also to ordinary copying machines, and so-called digital copying machines have been developed. In addition, since this digital copying machine is provided with various information processing functions, its demand is expected to increase further in the future.

  Currently, electrophotographic photoreceptors used in these systems generally have a so-called function in which a charge generation layer is formed directly on an electroconductive support or via an intermediate layer, and a charge transport layer is provided thereon. Separable laminated photoconductors are the mainstream. Furthermore, a surface protective layer is formed on the outermost surface of the photoreceptor in order to improve mechanical or chemical durability.

  In this function-separated laminated photoconductor, when a photoconductor whose surface is charged is exposed, light passes through the charge transport layer and is absorbed by the charge generation material in the charge generation layer. The charge generating material absorbs this light and generates charge carriers. The generated charge carriers are injected into the charge transport layer and move along the electric field generated by charging to neutralize the surface charge of the photoreceptor. As a result, an electrostatic latent image is formed on the surface of the photoreceptor.

  Therefore, the function-separated layered photoreceptor cannot mainly prevent the charge generation material having absorption from the near infrared portion to the visible portion and the absorption light of the charge generation material, that is, from the visible portion (yellow light region) to the ultraviolet portion. A combination with a charge transport material having absorption is often used.

  As a light source adapted to such a digital recording method, for example, a small and inexpensive semiconductor laser (LD) or light emitting diode (LED) with high reliability is often used. The oscillation wavelength region of the LD that is most often used at present is in the near infrared light region near 780 to 800 nm. The emission wavelength of a typical LED is 740 nm.

  The beam spot diameter is about 60 to 150 μm. For this reason, the current electrophotographic apparatus has a resolution of about 300 to 600 dpi, which is not sufficient as a high-resolution photographic tone. In order to narrow this down to a dot diameter of about 30 μm equivalent to 1200 dpi or a dot diameter of about 15 μm equivalent to 2400 dpi, an ultra-high precision optical component or a large optical member is required, which can be put into practical use in terms of cost and space. It wasn't. In order to solve this problem, it is considered effective to shorten the wavelength of the light source. JP-A-5-19598 proposes an electrophotographic apparatus using a short wavelength laser.

On the other hand, recently, purple to blue short wavelength LDs and LEDs having an oscillation wavelength of 400 to 450 nm have been developed and listed as writing light sources corresponding to this digital recording system. For example, when a short wavelength LD whose oscillation wavelength is approximately half that of a conventional near-infrared region LD is used as a writing light source, the spot diameter of the laser beam on the photoreceptor is expressed as shown in the following formula (A). Theoretically it can be made quite small. Therefore, they are very advantageous for increasing the writing density or resolution of the latent image.
(Where d is the spot diameter on the photoreceptor, λ is the wavelength of the laser light, f is the focal length of the fθ lens, and D is the lens diameter.)

  In addition, this short wavelength LD and LED have advantages such as compactness of the electrophotographic apparatus including the optical system and speeding up of the electrophotographic system. Therefore, high sensitivity corresponding to the LD or LED oscillation light source of about 400 to 450 nm. There is a demand for highly stable electrophotographic photoreceptors.

  As described above, the mainstream of the electrophotographic photosensitive member is a function separation type laminated photosensitive member. In the case of this layer structure, the charge transport layer is usually located above the charge generation layer, so that high sensitivity can be achieved by efficiently sending short wavelength LD, which is writing light, and LED irradiation light through the charge transport layer to the charge generation layer. There is a need. That is, it becomes important that the charge transport layer does not absorb these lights. A typical charge transport layer is a solid solution film of about 10 to 30 μm in which a low molecular charge transport material is molecularly dispersed in a binder resin. As the binder resin, a bisphenol-based polycarbonate resin or a copolymer of it and other resins is used in most electrophotographic photoreceptors. Since this bisphenol-based polycarbonate resin does not have spectral absorption in the wavelength range of 390 to 460 nm, it does not hinder writing light transmission.

  On the other hand, as a conventional charge transport material, 1,1-bis (p-diethylaminophenyl) -4,4-diphenyl-1,3-butadiene (Japanese Patent Laid-Open No. 62-30255), 5 -[4- (N, N-di-p-tolylamino) benzylidene] -5H-dibenzo [a, b] cycloheptene (JP-A 63-225660), pyrene-1-aldehyde 1,1-diphenylhydrazone ( However, these charge transport materials have absorption in the wavelength range of 390 to 460 nm, and the short wavelength LD and LED writing light are absorbed near the surface of the charge transport layer. As a result, the charge generation layer cannot be reached, and the sensitivity is not shown in principle.

  Furthermore, in Japanese Patent Application Laid-Open Nos. 55-67778 and 9-190054, when light in the wavelength region absorbed by the charge transport layer is used, the chargeability is decreased and the residual potential is increased in repeated use. As described, the light absorption of the charge transport material adversely affects repeated fatigue as well as sensitivity reduction.

  An electrophotographic apparatus using an LD having an oscillation wavelength of 400 to 500 nm as a light source is disclosed in Japanese Patent Laid-Open No. 9-240051. The layer structure of the electrophotographic photosensitive member used in this electrophotographic apparatus is a layer structure in which a charge transport layer and a charge generation layer are sequentially laminated on a conductive support for the purpose of high resolution. However, in the case of this photoreceptor layer structure, a fragile and thin charge generation layer is formed on the outermost surface, so that it becomes susceptible to mechanical and chemical hazards due to charging, development, transfer and cleaning means, and it is used repeatedly. This is not practical because the photoconductor deteriorates significantly due to the above. At the same time, an electrophotographic photosensitive member having a single layer structure is also disclosed, but this has a problem that it is difficult to realize the high sensitivity of the constituent material design of the photosensitive member and the function separation type laminated photosensitive member.

  Furthermore, electrophotographic printers and electrophotographic copiers that use electrophotographic methods are now becoming faster, smaller, and higher in image quality. As a result, the diameter of the photoconductor is reduced and the usage conditions in the electrophotographic process are increasing. It is getting stricter.

  In particular, a rubber blade is used in the installation and cleaning section of the charging roller around the photoconductor, and in order to perform sufficient cleaning, the rubber hardness and contact pressure must be increased. Is promoted, and potential fluctuations and sensitivity fluctuations occur, resulting in inconveniences such as a color balance of an abnormal image and a color image being lost and a problem in color reproducibility. In addition, when used for a long time, the ozone generated during charging may cause oxidative deterioration of the binder resin and charge transport material, and ionic compounds generated during charging, such as nitrate ions, sulfate ions, ammonium ions, organic acid compounds, and the like. The image quality deterioration due to accumulation on the body surface is a problem.

  For these reasons, it has become important to further improve the durability of the photoreceptor and improve the properties of the surface layer.

  Under these circumstances, the surface energy has been reduced by adding fluorine resin such as polytetrafluoroethylene, silicon resin such as polydimethylsiloxane to the photosensitive layer, etc. Has been tried.

  This measure is intended to improve the durability of the photoreceptor and reduce the amount of ionic compounds adhering to the surface layer of the photoreceptor. For example, a photosensitive resin surface layer containing fine particles of fluororesin (Japanese Patent Laid-Open No. 4-368953) or a siloxane copolymer polycarbonate as a binder resin is added to the photosensitive material surface layer to impart lubricity to the photosensitive material surface layer. Thus, there has been proposed a device that improves the cleaning property and prevents the occurrence of filming of hygroscopic substances such as toner and paper dust (Japanese Patent Laid-Open No. 5-113670).

  In addition, attempts have been made to prevent image quality degradation by forming a protective layer on the surface of the photoreceptor. For example, there has been proposed a method for improving the wear resistance of a photoreceptor surface layer by incorporating fillers such as silica gel and tin oxide into various resins into the photoreceptor surface layer (Japanese Patent Application Laid-Open No. 57-30843). JP-A-1-205171, JP-A-3-155558, JP-A-7-333881, JP-A-8-1587, JP-A-8-123053, JP-A-8-146541, JP-A-8 It has also been proposed to provide a surface protective layer composed of a crosslinked polysiloxane composed of a co-hydrolysis condensate of trifunctional alkoxysilane and tetrafunctional alkoxysilane (Japanese Patent Publication No. 5-046940).

  However, fluororesins such as polytetrafluoroethylene have extremely poor solubility in general-purpose solvents, and optically uniform dispersion is difficult, and when added to the resin, the fluororesin is not compatible. In addition, the resin particles agglomerate to give light scattering, and in many cases, the added resin particles bleed on the surface of the photoreceptor. Also, when polysiloxane is added, there is also a drawback that the tendency to bleed is strong and the effect is not permanent.

  When the protective layer is formed of polysiloxane, polysiloxane is generally a polymer having an excellent insulating property, and therefore, there is a disadvantage that the charge transporting property of the photoreceptor is hindered. Further, when the resin containing the filler is used as a protective layer, the surface hardness is improved, but generally the surface energy becomes high, the cleaning property becomes poor and the particles aggregate to cause light scattering. There was a problem.

  Further, according to these methods, there is a problem that the bright portion potential increases during long-term continuous repeated use, and image degradation such as a decrease in image density and a decrease in image resolution occurs.

  The present invention solves such conventional drawbacks and problems, and even when an ordinary writing light source having an oscillation wavelength range of about 780 to 800 nm is used, and particularly, an writing light source having an oscillation wavelength range of 400 to 450 nm. High-sensitivity electrophotographic photosensitive member that maintains excellent image quality even when it is used and does not fluctuate in potential even with repeated use, electrophotographic method using this electrophotographic photosensitive member, An object of the present invention is to provide an electrophotographic apparatus having a photographic photosensitive member and a process cartridge used in the electrophotographic apparatus. Another object of the present invention is to provide a novel bisphenol compound containing a long-chain alkyl group and a water repellent polymer using the same.

  In order to solve the above-mentioned problems, the present inventors have made extensive studies by paying attention to the photosensitive layer, particularly the surface portion. As a result, the photosensitive layer contains a polyurethane resin, a polyester resin or a polycarbonate resin having a specific structural unit. In addition, by forming a charge transport layer or a protective layer of a laminated photosensitive layer, it is possible to use a commonly used writing light source having an oscillation wavelength range of about 780 to 800 nm, particularly an oscillation of 400 to 450 nm. Even when an LD or LED writing light source in the wavelength range is used, a high-sensitivity electrophotographic photosensitive member that maintains excellent image quality and has no potential fluctuation even when used repeatedly. The electrophotographic method used, the electrophotographic apparatus having the electrophotographic photosensitive member, and the process cartridge used in the electrophotographic apparatus. Out, it has led to the completion of the present invention based on this finding.

That is, according to the present invention, a photosensitive layer containing a polyurethane resin, a polyester resin or a polycarbonate resin having at least a structural unit represented by the following general formula (1) is provided on a conductive support. An electrophotographic photoreceptor is provided.
[Wherein R ¹ and R ² represent a halogen atom, an unsubstituted or substituted alkyl group having 1 to 6 carbon atoms, an unsubstituted or substituted alkoxy group having 1 to 6 carbon atoms, or an unsubstituted or substituted aryl group (R ¹ R ² may be the same or different when there are a plurality of R ^{2 s} ), R ³ is an unsubstituted or substituted alkyl group having 1 to 6 carbon atoms, or a general formula — (CH ₂ ) _m represents an alkyl group represented by CH ₃ , a and b each represent an integer of 0 to 4, and n and m each represent an integer of 8 to 27. ]

  According to the invention, the photosensitive layer comprises a charge generating layer and a charge transport layer material containing a charge generating material, and a polyurethane resin, a polyester resin or a polycarbonate resin having the structural unit represented by the general formula (1). There is provided the above electrophotographic photosensitive member, comprising at least two charge transport layers contained therein, wherein a charge generation layer and a charge transport layer are provided on the conductive support in this order. The charge transport layer contains a polyurethane resin, a polyester resin, or a polycarbonate resin having a charge transport material and at least the structural unit represented by the general formula (1) on the first charge transport layer containing the charge transport material. The electrophotographic photosensitive member is characterized in that it has a laminated structure in which second charge transport layers are sequentially provided, and in particular, these charge transport layers are 390 to 460 n. An electrophotographic photosensitive member, characterized by transmitting monochromatic light of a wavelength area is provided. Further, a photosensitive layer is provided on the conductive support, and a protective layer containing a polyurethane resin, a polyester resin or a polycarbonate resin having at least the structural unit represented by the general formula (1) is provided thereon. A featured electrophotographic photoreceptor is provided.

  In addition, according to the present invention, there is provided an electrophotographic method characterized by performing charging, image exposure, development and transfer using the electrophotographic photosensitive member, and a writing light source of 400 to 450 nm, particularly in image exposure. There is provided an electrophotographic method using a semiconductor laser or a light emitting diode having an oscillation wavelength in a range.

  In addition, according to the present invention, there is provided an electrophotographic apparatus comprising the above-described electrophotographic photosensitive member and provided with a charging unit, an image exposing unit, a developing unit, and a transferring unit. An electrophotographic apparatus is provided in which the embedded light source is a semiconductor laser or a light emitting diode having an oscillation wavelength in the range of 400 to 450 nm.

  According to the present invention, the electrophotographic photosensitive member is integrally formed with at least one means selected from a charging means, an image exposure means, a developing means, a transfer means, and a cleaning means. And a process cartridge for an electrophotographic apparatus, characterized in that the writing light source in the image exposure means is a semiconductor laser or light emitting diode having an oscillation wavelength in the range of 400 to 450 nm. A process cartridge for an electrophotographic apparatus is provided.

Moreover, according to this invention, the long-chain alkyl group containing bisphenol compound represented by following General formula (2) is provided.
[Wherein R ¹ and R ² represent a halogen atom, an unsubstituted or substituted alkyl group having 1 to 6 carbon atoms, an unsubstituted or substituted alkoxy group having 1 to 6 carbon atoms, or an unsubstituted or substituted aryl group (R ¹ When a plurality of R ² are present, they may be the same or different), a and b each represent an integer of 0 to 4, and n represents an integer of 9 to 15. ]

Furthermore, according to this invention, the polymer characterized by having a structural unit represented by following General formula (3) is provided.

[Wherein R ¹ and R ² represent a halogen atom, an unsubstituted or substituted alkyl group having 1 to 6 carbon atoms, an unsubstituted or substituted alkoxy group having 1 to 6 carbon atoms, or an unsubstituted or substituted aryl group (R ¹ When a plurality of R ² are present, they may be the same or different), a and b each represent an integer of 0 to 4, and n represents an integer of 9 to 15. ]

  According to the present invention, a high-sensitivity electrophotographic photosensitive member that maintains excellent image quality and does not fluctuate in potential even when used repeatedly, an electrophotographic method using the electrophotographic photosensitive member, and the electronic An electrophotographic apparatus having a photographic photosensitive member and a process cartridge for use in the electrophotographic apparatus are provided. Further, according to the present invention, a blue semiconductor laser or a light emitting diode has high sensitivity even in an oscillation wavelength range of 400 to 450 nm. An electrophotographic photosensitive member having excellent mechanical durability and high image quality, an electrophotographic method using the electrophotographic photosensitive member, an electrophotographic apparatus having the electrophotographic photosensitive member, and a process cartridge used in the electrophotographic apparatus. Provided. The present invention makes a great contribution in the field of designing and producing machines and instruments used in electrophotographic processes such as electrophotographic printers and electrophotographic copying machines.

  Hereinafter, the present invention will be described in more detail. The present invention is characterized in that a photosensitive layer or a charge transport layer, or a second charge transport layer or a protective layer containing a polyurethane resin, a polyester resin or a polycarbonate resin having a specific structural unit is provided. An electrophotographic photoreceptor is provided.

The polyurethane resin, polyester resin, or polycarbonate resin used here is a resin having at least a structural unit represented by the following general formula (1). Hereinafter, these resins may be collectively referred to as “the present resin”.
[Wherein R ¹ and R ² represent a halogen atom, an unsubstituted or substituted alkyl group having 1 to 6 carbon atoms, an unsubstituted or substituted alkoxy group having 1 to 6 carbon atoms, or an unsubstituted or substituted aryl group (R ¹ R ² may be the same or different when there are a plurality of R ^{2 s} ), R ³ is an unsubstituted or substituted alkyl group having 1 to 6 carbon atoms, or a general formula — (CH ₂ ) _m represents an alkyl group represented by CH ₃ , a and b each represent an integer of 0 to 4, and n and m each represent an integer of 8 to 27. ]

Examples of the halogen atom represented by R ¹ and R ² include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

Examples of the unsubstituted or substituted alkyl group having 1 to 6 carbon atoms represented by R ¹ and R ² include a linear, branched, or cyclic alkyl group, and these alkyl groups include a fluorine atom, a cyano group, and a phenyl group. A phenyl group substituted with a group, a halogen atom, or a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms may be contained.

  Specifically, methyl group, ethyl group, n-propyl group, i-propyl group, t-butyl group, s-butyl group, n-butyl group, i-butyl group, trifluoromethyl group, 2-cyanoethyl group Benzyl group, 4-chlorobenzyl group, 4-methylbenzyl group, cyclopentyl group, cyclohexyl group and the like.

The unsubstituted or substituted alkoxy group having 1 to 6 carbon atoms represented by R ¹ and R ² is obtained by changing the above alkyl group to an alkoxy group, and includes a methoxy group, an ethoxy group, an n-propoxy group, i- Propoxy group, n-butoxy group, i-butoxy group, s-butoxy group, t-butoxy group, 2-hydroxyethoxy group, 2-cyanoethoxy group, benzyloxy group, 4-methylbenzyloxy group, trifluoromethoxy group Etc.

The unsubstituted or substituted aryl group represented by R ¹ and R ² represents a group including a heterocyclic group, and includes a phenyl group, a naphthyl group, a biphenylyl group, a terphenylyl group, a pyrenyl group, a fluorenyl group, 9,9-dimethyl- 2-fluorenyl group, azulenyl group, anthryl group, triphenylenyl group, chrycenyl group, fluorenylidenephenyl group, 5H-dibenzo [a, d] cycloheptenylidenephenyl group, thienyl group, benzothienyl group, furyl group, benzofuranyl group , A carbazolyl group, a pyridinyl group, a pyrrolidyl group, an oxazolyl group, and the like, and these groups optionally have the above alkyl group, alkoxy group or halogen atom as a substituent.

In addition, the C1-C6 unsubstituted or substituted alkyl group represented by R < ³ > is synonymous with the above.

The polyurethane resin, polyester resin or polycarbonate resin having the structural unit represented by the general formula (1) may have a group represented by the following general formula (4).
[Wherein, X ₁ represents an iminocarbonyloxy group, an oxycarbonyl group or an oxycarbonyloxy group, and X represents an unsubstituted or substituted aliphatic hydrocarbon divalent group having 2 to 20 carbon atoms, an unsubstituted or substituted alicyclic group. Divalent hydrocarbon group, unsubstituted or substituted aromatic hydrocarbon divalent group having 6 to 20 carbon atoms, divalent group to which these divalent groups are bonded, the following formula (i), (ii) or (iii)


[Wherein R ⁴ , R ⁵ , R ⁶ and R ⁷ represent a halogen atom, an unsubstituted or substituted alkyl group having 1 to 6 carbon atoms or an unsubstituted or substituted aryl group (R ⁴ , R ⁵ , R ⁶ , When a plurality of R ⁷ are present, they may be the same or different), c and d are integers of 0 to 4, e and f are integers of 0 to 3, Y Is a single bond, a linear alkylene group having 2 to 12 carbon atoms, an unsubstituted or substituted branched alkylene group having 3 to 12 carbon atoms, one or more alkylene groups having 1 to 10 carbon atoms and one or more oxygen atoms. A divalent group composed of an atom and a sulfur atom, —O—, —S—, —SO—, —SO ₂ —, —CO—, —COO— or the following formulas (iv) to (xiii)










(In the formula, Z ¹ represents an unsubstituted or substituted aliphatic hydrocarbon divalent group or an unsubstituted or substituted arylene group having 2 to 20 carbon atoms, and Z ² represents an unsubstituted or substituted aliphatic carbonized group having 2 to 20 carbon atoms. R ⁸ represents a hydrogen divalent group or an unsubstituted or substituted arylene group, and R ⁸ represents a halogen atom, an unsubstituted or substituted alkyl group having 1 to 6 carbon atoms, an unsubstituted or substituted alkoxy group having 1 to 6 carbon atoms, an unsubstituted or R ⁹ and R ¹⁰ are each a hydrogen atom, a halogen atom, an unsubstituted or substituted alkyl group having 1 to 6 carbon atoms, an unsubstituted or substituted alkoxy group having 1 to 6 carbon atoms, or an unsubstituted or substituted aryl group. R ⁹ and R ¹⁰ may be bonded to form a carbocyclic ring having 5 to 12 carbon atoms, and R ¹¹ , R ¹² , R ¹³ and R ¹⁴ are a hydrogen atom, a halogen atom and a carbon number of 1 No substitution or placement of ~ 6 Alkyl group, an unsubstituted or substituted alkoxy group or an unsubstituted or substituted aryl group having 1 to 6 carbon atoms, R ¹⁵ is a halogen atom, an unsubstituted or substituted alkyl group having 1 to 6 carbon atoms, carbon atoms 1-6 An unsubstituted or substituted alkoxy group or an unsubstituted or substituted aryl group, R ¹⁶ and R ¹⁷ represent a single bond or an alkylene group having 1 to 4 carbon atoms, and R ¹⁸ and R ¹⁹ have 1 to 6 carbon atoms. An unsubstituted or substituted alkyl group or an unsubstituted or substituted aryl group, g is an integer of 0-4, h is 1 or 2, i is an integer of 0-4, j is an integer of 0-20, k is 0-0 1 represents an integer of 2000). ]

  Specific examples of the unsubstituted or substituted aliphatic hydrocarbon divalent group represented by X and the unsubstituted or substituted alicyclic hydrocarbon divalent group include ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, and polytetramethylene ether. Glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, 1,5-hexane Diol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, neopentyl glycol 2-ethyl-1,6-hexanediol, 2-methyl-1,3-propanediol, 2- Til-1,3-propanediol, 2,2-dimethyl-1,3-propanediol, 1,3-cyclohexanediol, 1,4-cyclohexanediol, cyclohexane-1,4-dimethanol, 2,2-bis (4-hydroxycyclohexyl) propane, xylylenediol, 1,4-bis (2-hydroxyethyl) benzene, 1,4-bis (3-hydroxypropyl) benzene, 1,4-bis (4-hydroxybutyl) ) Divalent groups obtained by removing two hydroxy groups from diols such as benzene, 1,4-bis (5-hydroxypentyl) benzene, 1,4-bis (6-hydroxyhexyl) benzene and isophoronediol Can be mentioned.

  Examples of the unsubstituted or substituted aromatic hydrocarbon divalent group represented by X include the divalent groups derived from the above unsubstituted or substituted aryl group. The unsubstituted or substituted alkylene group includes the above unsubstituted group. Or the bivalent group induced | guided | derived from a substituted alkyl group can be mentioned.

There is no particular limitation on the divalent group composed of one or more C1-C10 alkylene group represented by Y and one or more oxygen atom and sulfur atom. For example, as a specific example, OCH ₂ CH ₂ O , OCH ₂ CH ₂ OCH ₂ CH ₂ O, OCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ O, OCH ₂ CH ₂ CH ₂ O, OCH ₂ CH ₂ CH ₂ CH ₂ O, OCH ₂ CH ₂ CH ₂ CH ₂ CH ₂ CH ₂ O, OCH ₂ CH ₂ CH ₂ CH ₂ CH ₂ CH ₂ CH ₂ CH ₂ O, CH ₂ O, CH ₂ CH ₂ O, CHEtOCHEtO, CHCH ₃ O, SCH ₂ OCH ₂ S, CH ₂ OCH ₂ , OCH ₂ OCH ₂ O, SCH ₂ CH ₂ OCH ₂ OCH ₂ CH ₂ S, OCH ₂ CHCH ₃ OCH ₂ CHCH ₃ O, SCH ₂ S, SCH ₂ CH ₂ S, SCH ₂ CH ₂ CH ₂ S, SCH ₂ CH ₂ CH ₂ CH ₂ S, SCH ₂ CH ₂ CH ₂ CH ₂ CH ₂ CH ₂ S, SCH ₂ CH ₂ SCH ₂ CH ₂ S, SCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ S and the like.

  Examples of the substituent for modifying the branched alkylene group having 3 to 12 carbon atoms include an unsubstituted or substituted aryl group and a halogen atom.

In the case where Z ¹ and Z ² are unsubstituted or substituted divalent hydrocarbon radicals, the diol in the case where X is an aliphatic hydrocarbon divalent radical or an alicyclic hydrocarbon divalent radical A divalent group excluding a hydroxy group can be mentioned.

Examples of the case where Z ¹ and Z ² are unsubstituted or substituted arylene groups include divalent groups derived from the unsubstituted or substituted aryl groups.

  Preferred examples when X is an aromatic hydrocarbon divalent group include bis (4-hydroxyphenyl) methane, bis (2-methyl-4-hydroxyphenyl) methane, and bis (3-methyl-4-hydroxy). Phenyl) methane, 1,1-bis <4-hydroxyphenyl) ethane, 1,2-bis (4-hydroxyphenyl) ethane, bis (4-hydroxyphenyl) phenylmethane, bis (4-hydroxyphenyl) diphenylmethane, 1 , 1-bis (4-hydroxyphenyl) -1-phenylethane, 1,3-bis (4-hydroxyphenyl) -1,1-dimethylpropane, 2,2-bis (4-hydroxyphenyl) propane, 2- (4-hydroxyphenyl) -2- (3-hydroxyphenyl) propane, 1,1-bis (4-hydroxyphenyl) -2-methylpropane, 2,2-bis (4-hydroxyphenyl) butane, 1,1-bis (4-hydroxyphenyl) -3-methylbutane, 2,2-bis (4-hydroxyphenyl) pentane, 2 , 2-bis (4-hydroxyphenyl) -4-methylpentane, 2,2-bis (4-hydroxyphenyl) hexane, 4,4-bis (4-hydroxyphenyl) heptane, 2,2-bis (4-hydroxyphenyl) nonane, bis (3,5-dimethyl-4-hydroxyphenyl) methane, 2,2-bis (3-methyl-4-hydroxyphenyl) propane, 2,2-bis (3-isopropyl- 4-hydroxyphenyl) propane, 2,2-bis (3-sec-butyl-4-hydroxyphenyl) propane, 2,2-bis (3-tert-butyl-4) Hydroxyphenyl) propane, 2,2-bis (3-cyclohexyl-4-hydroxyphenyl) propane, 2,2-bis (3-allyl-4-hydroxyphenyl) propane, 2,2-bis (3-phenyl-4) -Hydroxyphenyl) propane, 2,2-bis (3,5-dimethyl-4-hydroxyphenyl) propane, 2,2-bis (3-chloro-4-hydroxyphenyl) propane, 2,2-bis (3 5-dichloro-4-hydroxyphenyl) propane, 2,2-bis (3-bromo-4-hydroxyphenyl) propane, 2,2-bis (3,5-dibromo-4-hydroxyphenyl) propane, 2,2 -Bis (4-hydroxyphenyl) hexafluoropropane, 1,1-bis (4-hydroxyphenyl) cyclopentane, 1,1-bis (4-hydroxyphenyl) cyclohexane, 1,1-bis (3-methyl-4-hydroxyphenyl) cyclohexane, 1,1-bis (3,5-dimethyl-4-hydroxyphenyl) cyclohexane, 1,1-bis ( 3,5-dichloro-4-hydroxyphenyl) cyclohexane, 1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane, 1,1-bis (4-hydroxyphenyl) cycloheptane, 2, 2-bis (4-hydroxyphenyl) norbornane, 2,2-bis (4-hydroxyphenyl) adamantane, 4,4′-dihydroxydiphenyl ether, 4,4′-dihydroxy-3,3′-dimethyldiphenyl ether, ethylene glycol bis (4-Hydroxyphenyl) ether, 1,3-bis (4-H Loxyphenoxy) benzene, 1,4-bis (3-hydroxyphenoxy) benzene, 4,4′-dihydroxydiphenyl sulfide, 3,3′-dimethyl-4,4′-dihydroxydiphenyl sulfide, 3,3 ′, 5, 5′-tetramethyl-4,4′-dihydroxydiphenyl sulfide, 4,4′-dihydroxydiphenyl sulfoxide, 3,3′-dimethyl-4,4′-dihydroxydiphenyl sulfoxide, 4,4′-dihydroxydiphenyl sulfone, 3 , 3′-dimethyl-4,4′-dihydroxydiphenylsulfone, 3,3′-diphenyl-4,4′-dihydroxydiphenylsulfone, 3,3′-dichloro-4,4′-dihydroxydiphenylsulfone, bis (4 -Hydroxyphenyl) ketone, bis (3-methyl-4-hydroxyphenyl) T, 3,3,3 ′, 3′-tetramethyl-6,6′-dihydroxyspiro (bis) indane, 3,3 ′, 4,4′-tetrahydro-4,4,4 ′, 4′-tetra Methyl-2,2′-spirobi (2H-1-benzopyran) -7,7′-diol, trans-2,3-bis (4-hydroxyphenyl) -2-butene, 9,9-bis (4- Hydroxyphenyl) fluorene, 9,9-bis (4-hydroxyphenyl) xanthene, 1,6-bis (4-hydroxyphenyl) -1,6-hexanedione, α, α, α ′, α′-tetramethyl- α, α′-bis (4-hydroxyphenyl) -p-xylene, α, α, α ′, α′-tetramethyl-α, α′-bis (4-hydroxyphenyl) -m-xylene, 2,6 -Dihydroxydibenzo-p-dioxin, 2,6-dihydroxy Anthrene, 2,7-dihydroxyphenoxathiin, 9,10-dimethyl-2,7-dihydroxyphenazine, 3,6-dihydroxydibenzofuran, 3,6-dihydroxydibenzothiophene, 4,4′-dihydroxybiphenyl, 1,4 -Dihydroxynaphthalene, 2,7-dihydroxypyrene, hydroquinone, resorcin, 4-hydroxyphenyl-4-hydroxybenzoate, ethylene glycol-bis (4-hydroxybenzoate), diethylene glycol-bis (4-hydroxybenzoate), triethylene glycol- Bis (4-hydroxybenzoate), p-phenylene-bis (4-hydroxybenzoate), 1,6-bis (4-hydroxybenzoyloxy) -1H, 1H, 6H, 6H-perfluorohex 1,4-bis (4-hydroxybenzoyloxy) -1H, 1H, 4H, 4H-perfluorobutane, diols such as 1,3-bis (4-hydroxyphenyl) tetramethyldisiloxane, etc. And a divalent group in which two are removed.

  In the present specification, specific examples of the substituents having the same expression have the same definitions as those given above.

  The polyurethane resin used in the present invention is a resin having the structural unit represented by the general formula (1), and is produced by a known method such as polyaddition of diol and diisocyanate or polycondensation of diamine and bischloroformate. (Polymer Society, edited by Kyoritsu Shuppan Co., Ltd., “New Polymer Experimental Science 3, Synthesis and Reaction of Polymers (2) Synthesis of Condensed Polymers”, P117-119, P229-233).

  Specifically, it is produced mainly by a reaction between a diol represented by the general formula HO-A-OH [A represents a divalent group in the general formula (1)] and a diisocyanate. Known conditions can also be adopted for the reaction temperature, solvent, catalyst, molecular weight regulator and the like.

  In the polymerization reaction of diol and diisocyanate, it is desirable to use a terminal terminator as a molecular weight regulator in order to regulate the molecular weight. Therefore, a substituent attributed to the terminal terminator may be bonded to the terminal portion of the polyurethane resin used in the present invention.

  Examples of the terminal terminator used include known monovalent aromatic hydroxy compounds, haloformate derivatives of monovalent aromatic hydroxy compounds, monovalent carboxylic acids, and halide derivatives of monovalent carboxylic acids. These end capping agents may be used alone or in combination.

  Preferable terminal terminators include monovalent aromatic hydroxy compounds such as phenol, p-tert-butylphenol, p-cumylphenol, and phenyl chloroformate.

  The polyurethane resin thus obtained is used after removing impurities such as the catalyst and antioxidant used during the polymerization, unreacted diol and terminal stopper, or inorganic salts generated during the polymerization. .

  The polyester resin used in the present invention is a resin having a structural unit represented by the above general formula (1), and is a nucleophilic acyl substitution polymerization of a diol (including bisphenol) and a dicarboxylic acid derivative, a dicarboxylate salt and an aliphatic group. It can be produced by nucleophilic aliphatic hydrocarbon group substitution polymerization with hydrocarbon dihalide (edited by the Society of Polymer Science, Kyoritsu Shuppan Co., Ltd.) Synthesis of Polymers ”, P49-54, P77-95). Known conditions can also be adopted for the reaction temperature, solvent, catalyst, molecular weight regulator and the like.

  In the polymerization reaction of a diol and a dicarboxylic acid derivative, it is desirable to use a terminal terminator as a molecular weight regulator in order to regulate the molecular weight. Therefore, a substituent derived from the end terminator may be bonded to the terminal portion of the polyester resin used in the present invention.

  The polycarbonate resin used in the present invention is a resin having a structural unit represented by the above general formula (1), and can be produced by a polymerization reaction of bisphenol and a carbonic acid derivative (editor Honichi Kiyoichi, Nikkan Kogyo Shimbun) "Polycarbonate resin handbook").

  Transesterification method with bisaryl carbonate using at least one diol, solution polymerization method or interfacial polymerization method between diol and carbonyl compound such as phosgene, method using bischloroformate derived from diol, etc. Can be manufactured. Moreover, in order to adjust mechanical characteristics, a copolymer polycarbonate resin can also be used. Known conditions can also be adopted for the reaction temperature, solvent, catalyst, molecular weight regulator and the like.

  In the polymerization reaction of a diol and a dicarboxylic acid derivative, it is desirable to use a terminal terminator as a molecular weight regulator in order to regulate the molecular weight. Therefore, a substituent attributed to the terminal terminator may be bonded to the terminal portion of the polycarbonate resin used in the present invention.

  The molecular weight of the polyurethane resin, polyester resin or polycarbonate resin used in the electrophotographic photosensitive member of the present invention is 1000 to 1000000 in terms of polystyrene equivalent weight average molecular weight, and preferably 2000 to 500000. If the molecular weight is less than 1000, the mechanical strength becomes small and cracks occur during film formation, resulting in poor practicality. If the molecular weight exceeds 1000000, the solubility in a general solvent becomes poor or the viscosity of the solution increases. As a result, the coating becomes difficult and practically inconvenient.

  In order to improve mechanical properties, etc., a small amount of a branching agent can be added at the time of polymerization. Examples of the branching agent include an aromatic hydroxyl group, a haloformate group, a carboxylic acid group, a carboxylic acid halide group, or an active halogen atom. And compounds having 3 or more reactive groups selected from the above (may be the same or different). These branching agents may be used alone or in combination.

  The present invention is an electrophotographic photoreceptor in which a photosensitive layer containing at least the polyurethane resin, the polyester resin, or the polycarbonate resin (the resin) is formed on a conductive support. The present resin functions as a binder resin, and it is preferable that the photosensitive layer and the charge transporting layer be present at a position farthest from the conductive support. That is, when these resins are contained in the outermost layer of the photoreceptor, the effect of reducing the surface energy is exhibited.

  That is, the present resin is derived from the fact that one long-chain alkyl group always exists in the molecular structure of the structural unit. In general, it is known that those having a long-chain alkyl group in the molecule have a small critical surface tension like siloxane resins. For this reason, when the resin is used for the outermost layer, the surface frictional resistance of the photoreceptor is reduced, and high durability can be achieved. At the same time, it has the effect of reducing the amount of the ionic compound that is considered to be the cause of image quality deterioration, and the effect of maintaining high image quality over a long period of time is also achieved.

  The present resin used in the present invention has an advantage that the number of long chains of the long chain alkyl group can be selected widely, so that the degree of freedom in synthesis is high and the desired surface properties can be easily adjusted. However, usually, when the long chain alkyl group in the above general formula (1), n and m are 7 or less, the critical surface force is not sufficiently reduced, and when n and m are 28 or more, the crystallinity of the monomer In the present invention, those having n and m of 8 to 27 are employed.

  As described above, since the resin used in the present invention has an excellent function of reducing the surface energy of the photoreceptor, it is suitable as a binder for the photosensitive layer and the charge transporting layer, and also on the conductive support. Alternatively, it can also be used for the protective layer of a laminated electrophotographic photoreceptor in which a protective layer is sequentially provided on the charge transport layer.

  In the polyurethane resin, polyester resin or polycarbonate resin having the structural unit represented by the general formula (1), the content of the structural unit of the general formula (1) is 1 mol% or more, preferably 5 mol% or more. Preferably it is 20 mol% or more. If this ratio is less than 1 mol%, the critical surface tension becomes excessive, and the effect is not substantially exhibited.

  Thus, since the resin used in the present invention has an excellent function of reducing the surface energy of the photoreceptor, it is suitable as a binder for the photosensitive layer, the charge transport layer, and the protective layer.

  In the present invention, by including the resin in the photosensitive layer, the charge transport layer or the protective layer, the surface energy is reduced and desired characteristics such as maintaining high image quality can be obtained. Fillers can be included to adjust the properties. In the present invention, the resin and filler are simultaneously contained in the photosensitive layer, the charge transport layer or the protective layer, thereby further improving the wear resistance and maintaining high image quality. It is possible to obtain a highly sensitive electrophotographic photoreceptor having no durability.

  Fillers include titanium oxide, tin oxide, zinc oxide, zirconium oxide, indium oxide, silicon nitride, calcium oxide, barium sulfate, silica, colloidal silica, alumina, carbon black, fluorine resin fine powder, polysiloxane resin fine powder. , Polyethylene resin fine powders, graft copolymers having a core-shell structure, and the like.

  These fillers may be surface-treated with an inorganic substance or an organic substance in order to improve dispersibility. Generally, there are those treated with a silane coupling agent or treated with a fluorinated silane coupling agent as a water repellent treatment, and those treated with a higher fatty acid, and as inorganic treatment, the filler surface is treated with alumina, zirconia, tin oxide, silica. The thing which was done is mentioned.

  The filler content is usually 5 to 50%, preferably 10 to 40% on a weight basis with respect to the layer containing the filler. If it is less than 5%, the wearability may not be sufficiently improved, and if it exceeds 50%, the transparency of the entire photosensitive layer may be impaired.

  The average particle size of the filler is usually 0.05 to 1.0 μm, preferably 0.05 to 0.8 μm. If the thickness is less than 0.05 μm, improvement in wear resistance cannot be expected. If the thickness exceeds 1.0 μm, irregularities on the surface containing the filler increase, and the filler may damage the cleaning blade, resulting in poor cleaning. Absent.

  In the present invention, a charge transport material may be added to impart a charge transport function to the photosensitive layer or the charge transport layer, and the charge transport layer materials may be used alone or in combination of two or more.

  Among these charge transport materials, examples of the hole transport material include oxazole derivatives, oxadiazole derivatives (described in JP-A Nos. 52-139065 and 52-139066), imidazole derivatives, triphenylamine derivatives (Japanese Patent Laid-Open No. No. 3-285960), benzidine derivatives (described in JP-B-58-32372), α-phenylstilbene derivatives (described in JP-A-57-73075), hydrazone derivatives (JP-A-55-154955). No. 55-15694, No. 55-52063, No. 56-81850), triphenylmethane derivatives (described in Japanese Patent Publication No. 5-10983), anthracene derivatives (Japanese Unexamined Patent Publication No. 51-51). No. 94829), styryl derivatives (Japanese Patent Laid-Open No. 56-29245, ibid.) 8-198043 Patent described in JP), described in JP-carbazole derivatives (JP-58-58552), described in JP-pyrene derivatives (JP-A-2-94812) and the like.

  Examples of the polymer hole transport material include poly-N-carbazole derivatives, poly-γ-carbazolylethyl glutamate derivatives, pyrene-formaldehyde condensate derivatives, polyvinylpyrene, polyvinylphenanthrene, oxazole derivatives, imidazole derivatives, acetophenone derivatives. (Described in JP-A-7-325409), distyrylbenzene derivative, diphenethylbenzene derivative (described in JP-A-9-127713), a-phenylstilbene derivative (described in JP-A-9-297419), Butadiene derivatives (described in JP-A-9-80783), hydroxylated butadiene (described in JP-A-9-80784), diphenylcyclohexane derivatives (described in JP-A-9-80772), distyryltriphenylamine derivatives JP-A-9-222740), diphenyl distyrylbenzene derivatives (described in JP-A-9-265197 and 9-265201), stilbene derivatives (described in JP-A-9-212877), m- Phenylenediamine derivatives (described in JP-A-9-304956 and JP-A-9-304957), resorcin derivatives (described in JP-A-9-329907), triarylamine derivatives (JP-A 64-9964, JP 7-199503, JP-A-8-176293, JP-A-8-208820, JP-A-8-253568, JP-A-8-269446, JP-A-3-221522, JP-A-4-11627, JP-A-4-11627. 183719, JP-A-4-124163, JP-A-4-320420, JP-A-4-316543. And JP-A-5-310904, JP-A-7-56374, JP-A-8-62864, US Pat. Nos. 5,428,090 and 5,486,439).

  Among the charge transport materials, examples of the electron transport material include diphenoquinone derivatives, benzoquine derivatives, malononitrile derivatives, thiopyran derivatives, tetracyanoethylene derivatives, fluorenone derivatives such as 3,4,5,7-tetranitro-9-fluorenone, and dinitrobenzene derivatives. , Dinitroanthracene derivatives, dinitroacridine derivatives, nitroanthraquinone derivatives, dinitroanthraquino derivatives, succinic anhydride derivatives, maleic anhydride derivatives, dibromomaleic anhydride derivatives, and the like.

  The content of these charge transport materials is 0.2 to 3 parts by weight, preferably 0.4 to 1.5 parts by weight, with respect to 1 part by weight of the present resin.

  The electrophotographic photosensitive member of the present invention, the electrophotographic method using the electrophotographic photosensitive member, the electrophotographic apparatus having the electrophotographic photosensitive member, and the writing light source in the process cartridge used in the electrophotographic apparatus are conventionally used 780. A semiconductor laser (LD) having an oscillation wavelength around ˜800 nm, a typical light emitting diode (LED) having an oscillation wavelength at 740 nm, or the like is used. In addition, a semiconductor laser (LD) or a light emitting diode (LED) having an oscillation wavelength in the range of 400 to 450 nm that can support a digital recording method capable of increasing the writing density and resolution is used. Although the oscillation peak wavelength fluctuates to the longer or shorter wavelength side by several nm depending on the temperature environment, production lot, etc., the charge transport layer of the electrophotographic photosensitive member of the present invention is 390 to 460 nm. It is preferable that the light within the range is sufficiently transmitted. Also, since these LDs have a very narrow light intensity wavelength distribution, the charge transport layer does not need to transmit light in the entire wavelength range of 390 to 460 nm, and it is sufficient that at least one desired monochromatic light can be transmitted in this region. In this case, the transmittance of irradiation light is preferably 50% or more, and more preferably 90% or more.

The charge transport layer is actually not flat or smooth due to the shape of the photoconductor, such as a drum or sheet, or due to manufacturing problems, so there is a considerable decrease in the amount of light due to scattering or reflection of writing light. . The transmittance referred to in the present invention is simply the ratio of the light obtained by subtracting the scattered or reflected light inside the charge transport layer, that is, the light incident on the surface of the charge transport layer and the light emerging from the opposite surface. means. For example, FIG. 1 shows a schematic diagram of the transmission spectrum of the charge transport layer. From FIG. 1, the transmittance for light of wavelength λ2 (nm) within the wavelength range of 390 to 460 nm can be obtained from the following formula (B).
(In the formula, T ₁ represents the transmittance for light having a wavelength λ ₁ shorter than the wavelength λ ₂ in the 390 to 460 nm wavelength region, and similarly T ₂ represents the transmittance for wavelength λ _2. )

  The contact angle with respect to pure water on the surface of the electrophotographic photoreceptor of the present invention is preferably 85 ° or more. More preferably, it is 95 ° or more. That is, due to the development of water repellency derived from the long-chain alkyl group of the present resin, the surface energy of the photoreceptor is reduced when the contact angle with respect to pure water is 85 ° or more. When the contact angle with respect to pure water on the surface of the photoreceptor is less than 85 °, it is likely that the charged product or the fallen matter resulting from the toner or paper adheres to the surface repeatedly by the electrophotographic process, resulting in poor cleaning or a decrease in surface resistance. It tends to cause deterioration of the latent image (image flow). On the other hand, if the contact angle with respect to the pure is too large, the adhesion to the photosensitive member will be insufficient, so 140 ° or less is preferable.

  When a conventionally known binder resin having a low surface energy unit is used, the contact angle with respect to pure water may initially show a value of 100 ° or more on the surface of the photoreceptor due to the surface orientation of the resin. However, as the outermost layer is scraped due to mechanical wear or the like, the contact angle usually decreases significantly. For example, even when a siloxane copolymer polycarbonate known as a low surface energy binder resin is used as a binder resin, the contact angle after depletion is usually 85 ° or less. In order to maintain a low surface energy state after depletion, it is necessary to have many low surface energy units as a bulk of the photosensitive layer.

  The contact angle of the photosensitive layer with respect to the pure water of the photosensitive layer is defined as the contact angle of the surface where the photoreceptor is depleted by 1 μm in the actual machine. Since the contact angle is constant after the photoreceptor is worn down to near 1 μm instead of the outermost surface, the value at the place where 1 ± 0.3 μm is worn may be measured. In order to measure this, it is practical to load a photoconductor in a practical copier and to wear it by performing a live-action test.

  However, as a way to wear, for example, in a 20 ° C., 50% RH environment, about 1000 revolutions with a Taber abrasion tester (manufactured by Toyo Seiki Co., Ltd.) under the conditions of a load of 1000 g, a wear wheel CS-5, and a rotation speed of 60 rpm. The surface may be shaved. The contact angle for pure water can be measured by a droplet method using a contact angle meter CA-W type (manufactured by Kyowa Interface Chemical Co., Ltd.). As in the present invention, the contact angle with pure water at a position 1 ± 0.3 μm away from the outermost surface of the electrophotographic photosensitive member is preferably 85 ° or more and 140 ° or less. More preferably, it is 95 ° or more.

  The sliding angle with respect to pure water on the surface of the electrophotographic photoreceptor of the present invention is preferably 65 ° or less. Here, the sliding angle has the same definition as the physical property conventionally expressed as the falling angle. Conventionally, physical properties of the electrophotographic photosensitive member for reducing the surface energy include a friction coefficient, a water contact angle, and the like. However, even if the surface has a low coefficient of friction and high water repellency, it cannot always be said that it is effective for enhancing the durability of the photoreceptor. Therefore, it was found that by measuring the critical angle at which water droplets begin to slide from the substrate surface, that is, the falling angle, it becomes a model that prevents the ionic compound produced during charging from accumulating on the photoreceptor.

  This sliding angle is provided as a function attached to the contact angle measuring device and can be easily measured. Further, the sliding angle is a critical angle at which water starts to slide, and therefore the value varies depending on the weight of the water to be deposited. The heavier (that is, the larger the volume), the smaller the sliding angle. For this reason, the water to be deposited must always have the same weight. In this invention, it defines with the measured value at the time of measuring the volume of water as 15-20 microliters.

  As a result of actual measurement, it was confirmed that image flow was likely to occur in the actual machine evaluation test when the sliding angle was larger than 65 °. Also, it is expected that the smaller the sliding angle, the less likely it is to get dirt from the outside. However, if the sliding angle is less than 5 °, the surface is too slippery to form toner dots from the latent image on the surface of the electrophotographic photosensitive member. It was found that there was an error in the reproducibility of the image and this was a problem. Therefore, the sliding angle with respect to pure water on the surface of the electrophotographic photoreceptor is preferably 5 ° to 65 °, more preferably 5 ° to 35 °. This is obtained from the result of more strictly selecting the image evaluation result judged to be excellent.

  The present invention has clarified the relationship between the sliding angle on the surface of the photoreceptor and the image flow for the photoreceptor provided with the photosensitive layer containing the main body resin. However, this relationship is not limited to any material, and can be widely applied to the development of a photoreceptor so that it can be easily analogized. If necessary, as a model of external contaminants, the type of solvent is not limited to water, and evaluation can be carried out in place of alcohol-based solvents or general-purpose organic solvents to obtain development guidelines. At that time, naturally, the volume of various solvents to be deposited is not limited to 15 to 20 μl.

  The electrophotographic photosensitive member of the present invention is shown in FIGS. FIG. 2 is a schematic cross-sectional view of one electrophotographic photosensitive member of the present invention. The electrophotographic photoreceptor shown in FIG. 2 is a single-layer photoreceptor, in which a photosensitive layer 2 ′ in which a charge generating material 3 is dispersed in a charge transport medium 4 is formed on a conductive support 1. .

  This resin is used as a binder resin (binder) in a charge transport medium. In this case, other general-purpose binders can be used in combination for improving the dispersibility of the photosensitive member-forming coating solution and improving the strength of the photosensitive layer. Moreover, a filler can also be contained as needed.

  Examples of the substance having charge transporting ability used for the charge transporting medium 4 include the hole transporting substance and the electron transporting substance. The charge generation material 3 (charge generation material made of an inorganic or organic pigment) generates a charge carrier. In this case, the charge transport medium 4 mainly has a function of receiving and transporting charge carriers generated by the charge generating material 3. In this electrophotographic photosensitive member, the basic condition is that the charge generation material 3 and the resin of the present invention do not overlap in the absorption wavelength region mainly in the visible region.

  This is because in order to efficiently generate charge carriers in the charge generating material 3, it is necessary to transmit light to the surface of the charge generating material.

  FIG. 3 is a schematic sectional view of another electrophotographic photosensitive member of the present invention. The electrophotographic photosensitive member shown in FIG. 3 is a photosensitive layer 2 ″ comprising a laminate of a charge generation layer 5 mainly composed of a charge generation material 3 on a conductive support 1 and a charge transport layer 4 having a charge transport medium. Is formed. Examples of the substance having charge transporting ability used for the charge transporting medium 4 include the hole transporting substance and the electron transporting substance.

  This resin is used as a binder resin (binder) in a charge transport medium. In this case as well, other general-purpose binders can be used in combination for the same purpose as described above. Moreover, a filler can also be contained as needed.

  In this electrophotographic photosensitive member, the light transmitted through the charge transport layer 4 reaches the charge generation layer 5, and charge carriers are generated in the region. On the other hand, the charge transport layer 4 receives charge carrier injection and transports the charge carriers. The charge carriers necessary for light attenuation are generated by the charge generating material, and the charge carriers are transported by the charge transport layer 4.

  FIG. 4 is a schematic cross-sectional view of still another electrophotographic photosensitive member of the present invention. The electrophotographic photoreceptor shown in FIG. 4 is obtained by forming a second charge transport layer 4-2 on a charge transport layer 4-1. In the second charge transport layer 4-2, the present resin can be used as a binder resin, and other general-purpose binders can be used in combination for the same purpose as described above. Moreover, a filler can also be contained as needed.

  FIG. 5 is a schematic sectional view of still another electrophotographic photosensitive member of the present invention. The electrophotographic photoreceptor shown in FIG. 5 is obtained by reversing the stacking order of the charge generation layer 5 of FIG. 3 and the charge transport layer 4 containing the resin as a binder resin. The mechanism of charge carrier generation and transport is the same as described above. In this case, the protective layer 6 containing the present resin is formed on the charge generation layer 5. The protective layer 6 can contain a filler and other resins.

  In the electrophotographic photoreceptors shown in FIGS. 2 to 5, between the conductive support 1 and the photosensitive layers 2 ′ to 2 ″ ″, chargeability is improved, adhesion is improved, or laser writing light is interfered. An undercoat layer (not shown) may be formed for the purpose of preventing moire images by light.

The conductive support 1 in the present invention has a volume resistance of 10 ¹⁰ Ω or less, for example, aluminum, nickel, chromium, nichrome, copper, silver, gold, platinum, iron or other metal or tin oxide, oxidation After oxide or indium is deposited or sputtered on a film, cylindrical plastic, paper, etc., or a plate made of aluminum, aluminum alloy, nickel, stainless steel, etc. It is composed of a tube surface-treated by cutting, superfinishing, polishing or the like.

  In the present invention, the charge transport layer can be used in combination with a binder resin other than the present resin for the purpose of adjusting mechanical durability and the like. The charge transport layer of the present invention preferably transmits monochromatic light in the wavelength range of 390 to 460 nm. Therefore, the binder resin that can be used in combination is preferably one that transmits light in this wavelength range. For example, specifically polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polychlorinated Vinylidene, polyarylate, phenoxy resin, polycarbonate resin, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly-N-vinyl carbazole, acrylic resin, silicone resin, epoxy resin, melamine resin, urethane resin, phenol Examples thereof include thermoplastic or thermosetting resins such as resins and alkyd resins.

  In the present invention, the charge transport layer may contain a plasticizer or a leveling agent. As the plasticizer, those used as plasticizers for general resins such as halogenated paraffin, dimethylnaphthalene, dibutyl phthalate, dioctyl phthalate can be used as they are, and the amount used is 0 to 30% by weight based on the resin. The degree is appropriate. As the leveling agent, silicone oils such as dimethyl silicone oil and methylphenyl silicone oil, polymers or oligomers having a perfluoroalkyl group in the side chain are used, and the amount used is 0 to 1 with respect to the resin. Weight percent is appropriate.

  As a coating method for forming the charge transport layer, a dipping method, a spray coating method, a ring coating method, a roll coater method, a gravure coating method, a nozzle coating method, a screen printing method and the like are employed.

  The film thickness of the charge transport layers 4 and 4-1 is preferably about 3 to 50 μm. The thickness of the charge transport layer 4-2 is preferably 0.15 to 10 μm, more preferably 0.5 to 5 μm.

  Examples of the charge generation material 3 contained in the charge generation layer in the present invention include inorganic materials such as selenium, selenium-tellurium, cadmium sulfide, cadmium sulfide-selenium, and α-silicon, for example, CI Pigment Blue 25 (color index). CI 21180), CI Pigment Red 41 (CI 21200), CI Acid Red 52 (CI 45100), CI Basic Red 3 (CI 45210), an azo pigment having a carbazole skeleton (described in JP-A-53-95033), a distyrylbenzene skeleton Azo pigments having a triphenylamine skeleton (described in Japanese Patent Laid-Open No. 53-132347), azo pigments having a dibenzothiophene skeleton (Japanese Patent Laid-Open No. 54-21728) Gazette Description), azo pigments having an oxadiazole skeleton (described in JP-A-54-12742), azo pigments having a fluorenone skeleton (described in JP-A-54-22834), azo pigments having a bis-stilbene skeleton (Described in JP-A No. 54-17733), azo pigments having a distyryl oxadiazole skeleton (described in JP-A No. 54-2129), azo pigments having a distyryl carbazole skeleton (Japanese Unexamined Patent Publication No. 54-129) Azo pigments such as C.I. Pigment Blue 16 (CI 74100), indigo pigments such as C. I.But Brown 5 (CI 73410), C. I.But Die (CI 73030), and Argo Scarlet. B (manufactured by Bayer), Indenceence Scarlet R (Ba Organic materials such as perylene pigments such as Yell). These charge generation materials may be used alone or in combination of two or more.

Among these charge generating materials, those combined with a phthalocyanine pigment, in particular, can obtain an electrophotographic photoreceptor having high sensitivity and high durability. As the phthalocyanine pigment, the following general formula (5)
And a compound having a phthalocyanine skeleton represented by the formula:

  Here, M is a metal or non-metal (hydrogen). M (central metal) is H, Li, Be, Na, Mg, Al, Si, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Y , Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, In, Sn, Sb, Ba, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg, TI, La, Ce , Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Th, Pa, U, Np, Am, etc., simple substance or oxide, chloride, fluoride, water It is composed of two or more elements such as oxides and bromides, but is not limited to these elements.

  The charge generation material having the phthalocyanine skeleton may have the basic skeleton represented by the general formula (5), and may have a multimeric structure such as a dimer or trimer, or a higher order polymer. It may have a structure. In the basic skeleton, various substituents may be present.

  Among such phthalocyanines, oxotitanium phthalocyanine having TiO as the central metal M and metal-free phthalocyanine having H are particularly preferable in terms of photoreceptor characteristics.

  These phthalocyanines are also known to have various crystal systems, such as α, β, γ, m, y type in the case of oxotitanium phthalocyanine, α, β, γ, etc. in the case of copper phthalocyanine. It has a polycrystal system of

  Even in phthalocyanine having the same central metal, various characteristics change as the crystal system changes. Among them, it has been reported that the characteristics of the photoreceptor also change with such a crystal system change (Electrophotographic Society Journal, Vol. 29, No. 14 (1990)). For this reason, each phthalocyanine has an optimum crystal system in terms of the characteristics of the photoreceptor, and in particular for oxotitanium phthalocyanine, a Y-type crystal system is preferable.

  Further, these charge generation materials may be used by mixing two or more charge generation materials having a phthalocyanine skeleton.

  The charge generation layer can be provided by a casting method in which a binder resin is added or dissolved or dispersed in a charge generation material and a suitable solvent, if necessary, and coated and dried.

  Any conventionally known binder resin having good insulating properties can be used as the binder resin, and there is no particular limitation. For example, polyethylene, polyvinyl butyral, polyvinyl formal, polystyrene resin, phenoxy resin, polypropylene, acrylic resin, methacrylic resin, vinyl chloride resin, vinyl acetate resin, epoxy resin, polyurethane resin, phenol resin, polyester resin, alkyd resin, polycarbonate resin, Polyamide resins, silicone resins, melamine resins and other addition polymerization resins, polyaddition resins, polycondensation resins, and copolymer resins containing two or more of these resin repeating units, such as vinyl chloride-vinyl acetate In addition to insulating resins such as copolymers, styrene-acrylic copolymers, vinyl chloride-vinyl acetate-maleic anhydride copolymer resins, high molecular organic semiconductors such as poly-N-vinylcarbazole can be used. These binders can be used alone or as a mixture of two or more.

  The amount of the binder resin is suitably 0 to 5 parts by weight, preferably 0.1 to 3 parts by weight with respect to 1 part by weight of the charge generating material.

  Examples of the solvent used for preparing the dispersion or solution of the charge generation layer include N, N-dimethylformamide, toluene, xylene, monochlorobenzene, 1,2-dichloroethane, 1,1,1-trichloroethane, Examples include dichloromethane, 1,1,2-trichloroethane, trichloroethylene, tetrahydrofuran, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, ethyl acetate, butyl acetate, and dioxane.

  Examples of the dispersion method for the charge generation layer dispersion include a method using a ball mill, an ultrasonic wave, a homomixer, an attritor, and a sand mill. Examples of the application means include a dipping coating method, a blade coating method, and a spray coating method. A construction method, a beat coat method, etc. are mentioned.

  When the charge generating material is dispersed to form a photosensitive layer, the charge generating material preferably has an average particle diameter of 2 μm or less, preferably 1 μm or less in order to improve dispersibility in the layer. However, if the above particle size is too small, it tends to aggregate, and the resistance of the layer increases, the crystal defects increase, the sensitivity and repeatability decrease, or there is a limit in miniaturization, so the average particle size The lower limit of the diameter is preferably 0.01 μm. The film thickness of the charge generation layer is suitably about 0.01 to 5 μm, preferably 0.1 to 2 μm.

  As a method of forming the charge generation layer 5 on the conductive support 1, there is a method of forming by a vacuum thin film manufacturing method in addition to a method of forming by the casting method from the solution dispersion system. A vacuum deposition method, a glow discharge decomposition method, an ion plating method, a sputtering method, a reactive sputtering method, a CVD method, or the like is adopted as a method using a vacuum thin film manufacturing method.

  If any of these methods is further required, the charge generation layer 5 is formed by performing surface finishing, film thickness adjustment or the like by a method such as buffing.

  For example, in order to produce the electrophotographic photosensitive member shown in FIG. 2, fine particles of the charge generating material 3 are added to a solution obtained by dissolving a charge transporting material, the present resin, and, if necessary, another binder in combination. May also be dispersed together, coated on the conductive support 1, and dried to form the photosensitive layer 2 '.

  The thickness of the photosensitive layer 2 ′ is usually 3 to 100 μm, preferably 5 to 40 μm.

  The amount of the present resin in the photosensitive layer 2 ′ is 40 to 90% by weight, preferably 40 to 80%. The amount of the charge generating material 3 in the photosensitive layer 2 ′ is 0.1 by weight. -50%, preferably 1-20%.

  A charge transport material can be mixed and used in the photosensitive layer 2 ′ of the electrophotographic photoreceptor.

  In order to produce the electrophotographic photosensitive member shown in FIG. 3, the charge generating layer 5 is provided on the conductive support 1, and the resin or the like is further formed thereon together with a charge transporting material (hole transporting material or electron transporting material). The charge transport layer 4 may be formed by using a binder in combination and applying a solution obtained by dispersing filler fine particles in this solution, if necessary, followed by drying.

  The thickness of the charge generation layer 5 is usually 0.01 to 5 μm, preferably 0.1 to 2 μm, and the thickness of the charge transport layer 4 is usually 3 to 50 μm, preferably 5 to 40 μm. It is.

  When the charge generation layer 5 is of a type in which the charge generation layer material fine particles 3 are dispersed in a binder, the ratio of the charge generation material particles 3 to the charge generation layer 5 is usually on a weight basis. , 10 to 100%, preferably 50 to 100%.

  Further, the amount of the present resin in the charge transport layer 4 is 40 to 90% on a weight basis.

  In order to produce the electrophotographic photosensitive member shown in FIG. 4, the first charge transport layer 4-1 is provided on the conductive support 1, and the resin or other binder together with the charge transport material is further provided thereon. The second charge transport layer 4-2 is formed by dissolving, applying, and drying together. Further, the second charge transport layer 6 may be formed by applying and drying a solution in which fine particles of filler are dispersed if necessary.

  The thickness of the first charge transport layer 4-1 is usually 3 to 50 μm, preferably 5 to 40 μm, and the thickness of the second charge transport layer 4-2 is usually 0.15 to 10 μm. The thickness is preferably 1 to 10 μm.

  The amount of the present resin in the second charge transport layer 4-2 is usually 40 to 100%, preferably 40 to 90% on a weight basis.

  In order to produce the electrophotographic photosensitive member shown in FIG. 5, the charge generation layer 5 may be formed after the charge transport layer 4 is formed on the conductive support 1. The quantity ratio between the charge generation layer and the charge transport layer is as described in FIG. By forming the protective layer 6 containing the present resin on the charge generation layer 5 thus obtained, the electrophotographic photosensitive member shown in FIG. 5 can be produced.

  Further, the protective layer 6 may contain filler fine particles and other resins as necessary. As these filler fine particles and other resins, those used in the photosensitive layer can be used in the same manner as the filler fine particles, and other binder resins used in the charge transport layer can be used in the same manner.

  The thickness of the protective layer 6 is usually 0.15 to 10 μm, preferably 1 to 10 μm.

  The amount of the present resin shown in the protective layer 6 is usually 40 to 100%, preferably 40 to 90% on a weight basis.

  In all the above cases, when forming the filler-containing layer, the dispersion solvent to be used includes ketones such as methyl ethyl ketone, acetone, methyl isobutyl ketone, cyclohexanone, ethers such as dioxane, tetrahydrofuran, ethyl cellosolve, toluene, xylene, etc. Aromatics, halogens such as chlorobenzene and dichloromethane, and esters such as ethyl acetate and butyl acetate can be mentioned, and they are dispersed and pulverized using a ball mill, sand mill, vibration mill or the like. As the coating method, a dipping method, a spray coating method, a ring coating method, a roll coater method, a gravure coating method, a nozzle coating method, a screen printing method, or the like is employed.

  In all the electrophotographic photoreceptors of the present invention, an undercoat layer can be formed between the conductive support and the photosensitive layer. This undercoat layer is formed for the purpose of improving adhesiveness and preventing moire, improving the coatability of the upper layer and reducing residual potential.

  The undercoat layer is generally composed mainly of a resin. However, since the resin is coated on the photosensitive layer using a solvent, the resin may be a resin having high resistance to general organic solvents. desirable.

  Examples of such resins include water-soluble resins such as polyvinyl alcohol, casein, and sodium polyacrylate, alcohol-soluble resins such as copolymer nylon and methoxymethylated nylon, polyurethane, melamine resins, alkyd-melamine resins, and epoxy resins. Examples thereof include a curable resin that forms a three-dimensional network structure.

  In order to prevent moiré, optimize resistance, etc., add fine powders such as metal oxides such as titanium oxide, silica, alumina, zirconium oxide, tin oxide, and indium oxide, metal sulfide, and metal nitride. Also good.

  This undercoat layer can be formed using an appropriate solvent and coating method, as in the case of the photosensitive layer.

  Furthermore, it is also useful to use a silane coupling agent, a titanium coupling agent, a chromium coupling agent, or the like as the undercoat layer, for example, a metal oxide layer formed by a sol-gel method or the like.

In addition, for the undercoat layer, an anodized layer of Al ₂ O ₃ , an organic material such as polyparaxylylene (parylene), or an inorganic material such as SiO, SnO ₂ , TiO ₂ , ITO, or CeO ₂ is vacuumed. What was formed by the thin film preparation method can also be used conveniently.

  The thickness of the undercoat layer is usually from 0.01 to 20 μm, preferably from 0.05 to 15 μm, more preferably from 0.05 to 5 μm.

  Further, in the photosensitive layer, for the purpose of improving the charging property, a phenol compound, a hydroquinone compound, a hindered phenol compound, a hindered amine compound, a compound in which a hindered amine and a hindered phenol are present in the same molecule, and the like are added. I can do it.

  Further, in the electrophotographic photoreceptor of the present invention, an antioxidant can be used for the purpose of preventing the decrease in sensitivity and the increase in residual potential, in order to improve the environmental resistance. The antioxidant may be added to any layer containing an organic substance, but good results can be obtained by adding it to a layer containing a charge transport material.

  Antioxidants include 2,6-di-t-butyl-p-cresol, butylated hydroxyanisole, 2,6-di-t-butyl-4-ethylphenol, stearyl-β- (3,5-di- Monophenolic compounds such as -t-butyl-4-hydroxyphenyl) propionate, 2,2'-methylene-bis- (4-methyl-6-t-butylphenol), 2,2'-methylene-bis- (4 -Ethyl-6-t-butylphenol), 4,4'-thiobis- (3-methyl-6-t-butylphenol), 4,4'-butylidenebis- (3-methyl-6-t-butylphenol), etc. 1,1,3-tris- (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 1,3,5-trimethyl-2,4,6-tris (3,5 − -T-butyl-4-hydroxybenzyl) benzene, tetrakis- [methylene-3- (3 ', 5'-di-t-butyl-4'-hydroxyphenyl) propionate] methane, bis [3,3' -Bis (4′-hydroxy-3′-t-butylphenyl) butyric acid] polymer phenolic compounds such as cricol ester, tocopherols, N-phenyl-N′-isopropyl-p-phenylenediamine N, N′-di-sec-butyl-p-phenylenediamine, N-phenyl-N-sec-butyl-p-phenylenediamine, N, N′-di-isopropyl-p-phenylenediamine, N, N ′ -Paraphenylenediamines such as dimethyl-N, N'-di-t-butyl-p-phenylenediamine, 2,5-di-t-octylhydroquinone, 2,6-dido Hydroquinones such as decylhydroquinone, 2-dodecylhydroquinone, 2-dodecyl-5-chlorohydroquinone, 2-t-octyl-5-methylhydroquinone, 2- (2-octadecenyl) -5-methylhydroquinone, dilauryl-3,3 Organic sulfur compounds such as' -thiodipropionate, distearyl-3,3'-thiodipropionate, ditetradecyl-3,3'-thiodipropionate, triphenylphosphine, tri (nonylphenyl) phosphine, tri (di And organic phosphorus compounds such as nonylphenyl) phosphine, tricresylphosphine, and tri (2,4-dibutylphenoxy) phosphine.

  These compounds are known as antioxidants such as rubbers, plastics, fats and oils, and commercially available products can be easily obtained.

  The addition amount of the antioxidant in the present invention is usually 0.01 to 100 parts, preferably 0.1 to 30 parts with respect to 100 parts of the charge transport material on a weight basis.

  Next, the present invention provides an electrophotographic method characterized in that charging, image exposure, and transfer are performed using the above electrophotographic photosensitive member. The present invention also provides an electrophotographic apparatus having the above-described electrophotographic photosensitive member, and having a charging unit, an image exposure unit, and a transfer unit. Further, the electrophotographic photosensitive member described above and at least one means selected from a charging means, an image exposure means, a developing means, a transfer means, and a cleaning means are integrally formed to be detachable from the main body of the electrophotographic apparatus. A process cartridge for an electrophotographic apparatus is provided.

  The electrophotographic method, electrophotographic apparatus, and process cartridge for an electrophotographic apparatus will be described with reference to the drawings.

  FIG. 6 is a schematic view of an electrophotographic apparatus and a process cartridge for the electrophotographic apparatus of the present invention.

  Here, 7 represents the electrophotographic photosensitive member of the present invention, and the photosensitive member 7 represents a drum shape, but may be a sheet shape or an endless belt shape.

  For the charging charger 8, the pre-transfer charger 9, the transfer charger 10, the separation charger 11, and the pre-cleaning charger 12, known means such as a corotron, a scorotron, a solid state charger (solid state charger), and a charging roller are used.

  As the transfer means, the above charger can be generally used. However, as shown in FIG. 6, a transfer charger 10 and a separation charger 11 provided together are effective.

  The light sources such as the image exposure unit 13 and the charge removal lamp 14 are all luminescent materials such as fluorescent lamps, tungsten lamps, halogen lamps, mercury lamps, sodium lamps, light emitting diodes (LEDs), semiconductor lasers (LD), and electroluminescence (EL). In particular, an LD or LED having an oscillation wavelength in the range of 400 to 450 nm is preferably used for the image exposure unit 13. At this time, the beam diameter of the image exposure unit and the writing light source is preferably 10 to 30 μm in order to achieve a high resolution equivalent to 1200 to 2400 dpi.

  Various types of filters such as a sharp cut filter, a band pass filter, a near infrared cut filter, a dichroic filter, an interference filter, and a color temperature conversion filter can be used to irradiate only light in a desired wavelength range.

  Such a light source or the like irradiates the photosensitive member with light by providing a transfer process, a static elimination process, a cleaning process, or a pre-exposure process in combination with light irradiation in addition to the process shown in FIG.

  The toner developed on the photoconductor 7 by the developing unit 15 is transferred to the transfer paper 16, but not all is transferred, and the toner remains on the photoconductor 7. This residual toner is removed from the photoreceptor by the fur brush 17 and the cleaning brush 18.

  This cleaning may be performed only with the cleaning brush 18, and a known brush such as a fur brush or a mag fur brush is used as the cleaning brush.

  When the electrophotographic photosensitive member is positively (negatively) charged and image exposure is performed, a positive (negative) electrostatic latent image is formed on the surface of the photosensitive member. If this is developed with toner of negative (positive) polarity (electrodetection fine particles), a positive image can be obtained, and if developed with toner of positive (negative) polarity, a negative image can be obtained.

  A known method can be applied to the developing unit, and a known method is also used for the charge eliminating unit.

  FIG. 7 is a schematic view of another electrophotographic apparatus of the present invention. The photoconductor 21 is a photoconductor of the present invention, and is driven by driving rollers 22a and 22b. The photoconductor 21 is charged by a charger 23, image exposure by a light source 24, development (not shown), transfer using a charger 25, and a light source 26. The pre-cleaning exposure by, cleaning by the brush 27, and static elimination by the light source 28 are repeated. In FIG. 7, the photoconductor 21 (in this case, the support is translucent) is irradiated with pre-cleaning exposure light from the support side.

  The electrophotographic method and the electrophotographic apparatus illustrated above exemplify the embodiments of the present invention, and other embodiments are possible. 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, and image exposure and neutralization light irradiation may be performed from the support side. In addition, the light irradiation process is illustrated as image exposure, pre-cleaning exposure, and static elimination exposure. In addition, the pre-transfer exposure, pre-exposure of image exposure, and other known light irradiation processes are provided to irradiate the photosensitive member with light. It can also be done.

  The image forming means performed in this way may be fixedly incorporated in a copying apparatus, facsimile, or printer, but may be incorporated in these apparatuses in the form of a process cartridge. A process cartridge is a device and a part that includes a photosensitive member and includes a charging unit, an exposure unit, a developing unit, a transfer unit, a cleaning unit, and a charge eliminating unit.

  There are many examples of the shape of the process cartridge. Here, one example is shown in FIG. This process cartridge comprises the electrophotographic photosensitive member 29 of the present invention, a charging charger 30, a cleaning brush 31, an image exposure unit 32, and a developing roller 33.

The long-term alkyl group-containing bisphenol compound represented by the general formula (2) of the present invention is a novel compound having two long-chain alkyl groups in the molecule and a pair of chain lengths on the left and right. This novel compound is synthesized from twice the amount of phenol and a long-chain alkyl ketone in the presence of concentrated hydrochloric acid or hydrogen chloride. This synthesis method itself is known, for example, Journal of Chemical Society of Japan, 1982, No. 8, p 1363.
Or

  The above synthesis is carried out in one step, but its reactivity is low, so the reaction temperature, reaction time, catalyst, etc. need to be optimized as necessary. For example, the reaction temperature is 20 to 110 ° C., preferably 50 to 80 ° C. When a catalyst is used, 3-mercaptopropionic acid or the like is used.

  The novel bisphenol compound thus obtained has excellent light resistance and is useful as a light stabilizer. Moreover, this compound is useful not only as a monomer but also as a raw material for a water-repellent polymer. Furthermore, since this compound has two long-chain alkyl groups in the molecule, it not only has good water repellency, but the long-chain alkyl groups are symmetrical and molecularly balanced. It has good thermal stability. In this compound, when n is 8 or less, the water repellency is inferior, and when n is 16 or more, the melting point is too low.

  Moreover, the polymer which has a structural unit represented by General formula (3) of this invention has a novel frame | skeleton as a structural unit. This polymer has two long-chain alkyl groups symmetrically in the molecule, and has a higher water repellency than conventional long-chain alkyl group-containing polymers. As described above, various polymers (polyurethane resin, polycarbonate resin, polyester resin, etc.) can be synthesized from the bisphenol compound represented by the general formula (2) by a conventionally known method. This polymer can be synthesized with a polymer having the desired physical properties (water repellency, water slidability, etc.) by selecting a copolymer species, and since this polymer does not have surface orientation like a silicone system, Sustained effect is recognized, and it can be expected not only as a binder resin for photoreceptors but also for a wide range of applications and uses.

  The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. All parts are parts by weight.

Production Example 1 (Production of a compound represented by the general formula (2))
19 parts of phenol, 20 parts of 14-heptacosanone, 13 parts of concentrated hydrochloric acid and 0.01 part of 3-mercaptopropionic acid were placed in a stirred reaction vessel and reacted at 80 ° C. for 20 hours. After the reaction, the reaction mixture was cooled, water and acetic acid were added, and the organic layer was extracted. The organic layer was washed 3 times with water and finally dried over anhydrous magnesium sulfate. The filtrate was concentrated, and column chromatography with silica gel was performed using a toluene / ethyl acetate (5/1) mixed solvent, followed by recrystallization purification with toluene, and the bisphenol compound represented by the following structural formula (k) was converted into 22 Got a part.

The melting point of this compound was 114.5 to 115.0 ° C., and the results of elemental analysis were as follows, which agreed with the value calculated from the structural formula.
C% H%
Actual value 82.77 11.64
Calculated value 82.92 11.42

Production Examples 2 and 3 (Production of the compound represented by the general formula (2))
Further, 14-heptacosanone was replaced with 11-heneicosanone and 17-tritriacontanone to synthesize corresponding bisphenol compounds.

Production Example 4 (Production of polycarbonate resin)
Bisphenol represented by the structural formula (k) and bisphenol Z are equimolar, 4-tert-butylphenol as a molecular weight regulator is placed in a stirred reaction vessel, and sodium hydroxide and sodium hydrosulfite are added to water under a nitrogen stream. The liquid dissolved in was added and dissolved by stirring. Then, it cooled to 20 degreeC and added the liquid which melt | dissolved the bis (trichloromethyl) carbonate which is a trimer of phosgene in the dichloromethane, and made it react, forming an emulsion. Thereafter, the mixture was stirred at room temperature for 15 minutes, 0.01 part of triethylamine was added as a catalyst, and the mixture was stirred at room temperature for 120 minutes. Thereafter, 200 parts of dichloromethane was added to separate the organic layer. The organic layer was washed with a 3% aqueous sodium hydroxide solution and a 2% aqueous hydrochloric acid solution in this order, and finally with water. This organic layer was dropped into a large amount of methanol to precipitate a white polycarbonate resin, thereby obtaining a polycarbonate resin (resin No. 1) represented by the following structural formula.

When the molecular weight of this polycarbonate resin was measured by gel permeation chromatography, the polystyrene-reduced molecular weight was 77500 in terms of number average molecular weight and 198,700 in terms of weight average molecular weight. Moreover, the glass transition temperature calculated | required from the differential scanning calorimetry was 46.1 degreeC. The results of elemental analysis were as follows and agreed with the values calculated from the structural formula.
C% H%
Actual value 80.07 9.36
Calculated value 80.05 9.11

Production Example 5 (Production of polycarbonate resin)
Bisphenol and bisphenol Z represented by the following structural formula (m) are equimolar, 4-tert-butylphenol as a molecular weight regulator is placed in a stirred reaction vessel, and sodium hydroxide and sodium hydrosulfite are added to water under a nitrogen stream. The liquid dissolved in was added and dissolved by stirring. Then, it cooled to 20 degreeC and added the liquid which melt | dissolved the bis (trichloromethyl) carbonate which is a trimer of phosgene in the dichloromethane, and made it react, forming an emulsion. Thereafter, the mixture was stirred at room temperature for 15 minutes, 0.01 part of triethylamine was added as a catalyst, and the mixture was stirred at room temperature for 120 minutes. Thereafter, 200 parts of dichloromethane was added to separate the organic layer. The organic layer was washed with a 3% aqueous sodium hydroxide solution and a 2% aqueous hydrochloric acid solution in this order, and finally with water. This organic layer was dropped into a large amount of methanol to precipitate a white polycarbonate resin, thereby obtaining a polycarbonate resin (resin No. 2) represented by the following structural formula.

When the molecular weight of this polycarbonate resin was measured by gel permeation chromatography, the polystyrene-reduced molecular weight was 44700 in terms of number average molecular weight and 116300 in terms of weight average molecular weight. Moreover, the glass transition temperature calculated | required from the differential scanning calorimetry was 71.3 degreeC. The results of elemental analysis were as follows and agreed with the values calculated from the structural formula.
C% H%
Actual value 78.59 8.02
Calculated value 78.74 7.87

Production Example 6 (Production of polyurethane resin)
Under a nitrogen stream, 4,4′-decylidenebisphenol was dissolved in 25 ml of dried 1,3-dimethyl-2-imidazolidinone at 60 to 65 ° C. Next, a solution prepared by dissolving 4,4′-diphenylmethane diisocyanate in 10 ml of dried 1,3-dimethyl-2-imidazolidinone was added dropwise over 15 minutes. Then, it heated at 95-100 degreeC and stirred for 2 hours. After adding 0.05 g of dibutyltin laurate as a catalyst and further stirring for 2 hours, 0.08 part of phenol was added and stirred for 30 minutes. Subsequently, after cooling to room temperature, the reaction solution was dropped into 460 ml of methanol. The resulting precipitate was collected by filtration and washed with methanol. This was subjected to tetrahydrofuran dissolution-methanol precipitation twice to obtain a polyurethane resin (resin No. 3) represented by the following structural formula.

When the molecular weight of this polyurethane resin was measured by gel permeation chromatography, the polystyrene-reduced molecular weight was 10790 in terms of number average molecular weight and 12,900 in terms of weight average molecular weight. The results of elemental analysis were as follows and agreed with the values calculated from the structural formula.
C% H% N%
Actual value 77.21 7.05 4.72
Calculated value 77.06 6.99 4.86

Production Example 7 (Production of polyester resin)
A solution in which terephthalic acid chloride is dissolved in 60 ml of dehydrated chloroform, dissolved in 80 ml of 2% aqueous sodium hydroxide solution in a reaction vessel equipped with a stirrer and then water-cooled and vigorously stirred in a nitrogen stream. And a polymerization reaction was carried out at 20 ° C. for 3 hours. Thereafter, the organic phase is taken out, washed four times with 350 g of water, dropped into acetone, taken out of the polymer, further dissolved in tetrahydrofuran, filtered, dropped into methanol and purified by reprecipitation three times. A polyarylate resin (resin No. 4) represented by the following structural formula was obtained.

When the molecular weight of this polyarylate resin was measured by gel permeation chromatography, the molecular weight in terms of polystyrene was 15400 in terms of number average molecular weight and 26900 in terms of weight average molecular weight. The results of elemental analysis were as follows and agreed with the values calculated from the structural formula.
C% H%
Actual value 78.80 7.03
Calculated value 78.92 7.06

Production Example 8 (Production of polycarbonate resin)
4,4′-Decylidenebisphenol and 4-t-butylphenol as a quantity regulator are placed in a reaction vessel equipped with a stirrer, added to a solution of sodium hydroxide and sodium hydrosulfite dissolved in water under a nitrogen stream, and stirred. And dissolved. Then, it cooled to 20 degreeC and added the liquid which melt | dissolved the bis (trichloromethyl) carbonate which is a trimer of phosgene in the dichloromethane, and made it react, forming an emulsion. After stirring for 15 minutes, 0.01 g of triethylamine was added as a catalyst, and the reaction was stirred at room temperature for 120 minutes. Subsequently, 200 g of dichloromethane was added to separate the organic phase. This organic phase was washed with a 3% aqueous sodium hydroxide solution and a 2% aqueous hydrochloric acid solution in that order, and finally with water. This organic phase was dropped into a large amount of methanol to precipitate a white resin to obtain a polycarbonate resin (resin No. 5) represented by the following structural formula.

When the molecular weight of this polycarbonate resin was measured by gel permeation chromatography, the molecular weight in terms of polystyrene was 65300 in terms of number average molecular weight and 141000 in terms of weight average molecular weight. The results of elemental analysis were as follows and agreed with the values calculated from the structural formula.
C% H%
Actual value 78.55 8.19
Calculated value 78.38 8.01

( Reference Example 4 )
By coating and drying an undercoat layer coating solution, a charge generation layer coating solution, and a charge transport layer coating solution in the following composition on a φ30 mm aluminum drum in sequence, an undercoat layer of 3.5 μm A 0.2 μm charge generation layer and a 30 ± 1 μm charge transport layer were formed to prepare an electrophotographic photosensitive member.

[Coating liquid for undercoat layer]
Alkyd resin (beccosol, 1307-60-EL,
Dainippon Ink & Chemicals, Inc.) 6 parts Melamine resin (Super Becamine G-821-60,
Dainippon Ink & Chemicals, Inc.) 4 parts Titanium oxide 40 parts Methyl ethyl ketone 50 parts

[Coating liquid for charge generation layer]
Oxotitanium phthalocyanine pigment 3 parts Polyvinyl butyral (UCC: XYHL) 2 parts Tetrahydrofuran 95 parts

[Coating liquid for charge transport layer]
7 parts of charge transport material represented by the following structural formula (a) 10 parts of polyurethane resin (resin No. 3) obtained in Production Example 6

150 parts of methylene chloride

( Reference Example 5 )
By coating and drying an undercoat layer coating solution, a charge generation layer coating solution, and a charge transport layer coating solution in the following composition on a φ30 mm aluminum drum in sequence, an undercoat layer of 3.5 μm A 0.2 μm charge generation layer and a 30 ± 1 μm charge transport layer were formed to prepare an electrophotographic photosensitive member.

[Coating liquid for undercoat layer]
Alkyd resin (beccosol, 1307-60-EL,
Dainippon Ink & Chemicals, Inc.) 6 parts Melamine resin (Super Becamine G-821-60,
Dainippon Ink & Chemicals, Inc.) 4 parts Titanium oxide 40 parts Methyl ethyl ketone 50 parts

[Coating liquid for charge generation layer]
Oxotitanium phthalocyanine pigment 3 parts Polyvinyl butyral (UCC: XYHL) 2 parts Tetrahydrofuran 95 parts

[Coating liquid for charge transport layer]
7 parts of charge transport material represented by the structural formula (a) 10 parts of polyarylate resin (resin No. 4) obtained in Production Example 7 150 parts of methylene chloride

( Reference Example 6 )
By coating and drying an undercoat layer coating solution, a charge generation layer coating solution, and a charge transport layer coating solution in the following composition on a φ30 mm aluminum drum in sequence, an undercoat layer of 3.5 μm A 0.2 μm charge generation layer and a 30 ± 1 μm charge transport layer were formed to prepare an electrophotographic photosensitive member.

[Coating liquid for undercoat layer]
Alkyd resin (beccosol, 1307-60-EL,
Dainippon Ink & Chemicals, Inc.) 6 parts Melamine resin (Super Becamine G-821-60,
Dainippon Ink & Chemicals, Inc.) 4 parts Titanium oxide 40 parts Methyl ethyl ketone 50 parts

[Coating liquid for charge generation layer]
Oxotitanium phthalocyanine pigment 3 parts Polyvinyl butyral (UCC: XYHL) 2 parts Tetrahydrofuran 95 parts

[Coating liquid for charge transport layer]
7 parts of the charge transport material represented by the structural formula (a) 10 parts of the polycarbonate resin (resin No. 5) obtained in Production Example 8 150 parts of methylene chloride

(Comparative Example 1)
An electrophotographic photosensitive member was produced in the same manner as in Reference Example 4 except that the charge transport layer coating solution in Reference Example 4 was changed to the following.
[Coating liquid for charge transport layer]
Charge transport material represented by the structural formula (a) 7 parts Bisphenol Z-type polycarbonate (PCX-5, manufactured by Teijin Chemicals Ltd.) 10 parts Methylene chloride 150 parts

[Evaluation]
After the electrophotographic photoreceptors of Examples and Comparative Examples thus prepared were used for mounting, they were mounted on a Ricoh copier Imagio MF200, charged, and then irradiated with light through an original drawing to be electrostatically charged. A latent image was formed, developed using a dry developer, and the obtained image (toner image) was electrostatically transferred onto plain paper, and an image evaluation test was performed on the basis of 50,000 sheets to be fixed.

  When the electrophotographic photosensitive member of Example was used, a good transfer image was obtained even after 50,000 sheets, whereas when the electrophotographic photosensitive member of Comparative Example 1 was used, the image quality was improved after 50,000 sheets. A decrease was observed. Similarly, when the electrophotographic photosensitive member of the example was used and a wet developer was used as the developer, a clear transferred image was obtained.

  As described above, according to the electrophotographic method using the electrophotographic photosensitive member of the present invention, excellent image quality is maintained as compared with the conventional one using the electrophotographic photosensitive member, and the potential for repeated use is also increased. It was found that the product was highly sensitive with high durability and no fluctuation.

( Reference Example 7 )
A mixture having the following composition was placed in a ball mill pot, and an alumina ball having a diameter of 10 m was used and ball milled for 48 hours to prepare an undercoat layer coating solution. This coating solution was applied on an aluminum plate support and then dried at 130 ° C. for 20 minutes to form an undercoat layer having a thickness of about 4 μm. Next, a mixture having the following composition was pulverized and mixed in a ball mill, and the obtained dispersion was applied onto the undercoat layer with a doctor blade at a wet gap of about 35 μm and naturally dried to form a charge generation layer. Further, a charge transport layer coating liquid having the following composition is applied onto the charge generation layer with a doctor blade and dried at 80 ° C. for 2 minutes and then at 130 ° C. for 20 minutes to form a charge transport layer having a thickness of about 25 μm. A photoconductor was prepared.

[Coating liquid for undercoat layer]
Oil-free alkyd resin (Dainippon Ink Chemical Co., Ltd .: Beckolite M6401) 1.5 parts Melamine resin (Dainippon Chemical Co., Ltd .: Super Becamine G-821) 1 part Titanium dioxide (Ishihara Sangyo Co., Ltd .: Taipei CR-EL 5 parts 2-butanone 22.5 parts

[Coating liquid for charge generation layer]
Bisazo compound represented by the following structural formula (b) 7.5 parts Polyester resin [Toyobo Co., Ltd .: Byron 200] 2.5 parts Tetrahydrofuran 500 parts

[Coating liquid for charge transport layer]
7 parts of charge transport material represented by the following structural formula (c) 10 parts of polyurethane resin (resin No. 3) obtained in Production Example 6 100 parts of tetrahydrofuran

( Reference Example 8 )
In the same manner as in Reference Example 7 , an undercoat layer and a charge generation layer were sequentially formed on an aluminum plate support. Next, a first charge transport layer coating solution having the following composition was applied onto the charge generation layer with a doctor blade, dried at 80 ° C. for 2 minutes, and then at 130 ° C. for 20 minutes to give a first charge having a thickness of about 20 μm. A transport layer was formed. Further, a second charge transport layer coating solution having the following composition was applied onto the first charge transport layer with a doctor blade, dried at 80 ° C. for 2 minutes, and then at 130 ° C. for 20 minutes to form a second charge having a thickness of about 5 μm. A charge transport layer was formed to prepare a photoreceptor.

[Coating liquid for first charge transport layer]
Charge transport material represented by the following structural formula (d) 7 parts Polycarbonate resin [manufactured by Teijin: Panlite C-1400] 10 parts Tetrahydrofuran 100 parts

[Coating liquid for second charge transport layer]
Charge transport material represented by the structural formula (d) 3 parts Resin No. Polycarbonate resin having the same repeating unit as 5 (weight average molecular weight: 237700) 5 parts Tetrahydrofuran 40 parts Cyclohexane 140 parts

( Reference Example 9 )
As in Reference Example 8 , an undercoat layer, a charge generation layer, and a first charge transport layer were sequentially formed on an aluminum plate support. Next, a coating solution for the second charge transport layer having the following composition was applied onto the first charge transport layer with a doctor blade, dried at 80 ° C. for 2 minutes, and then at 130 ° C. for 20 minutes to give a second about 5 μm thick second solution. A charge transport layer was formed to prepare a photoreceptor.

[Coating liquid for second charge transport layer]
Charge transport material represented by the following structural formula (e) 3 parts Polyarylate resin (resin No. 4) obtained in Production Example 7 5 parts Titanium oxide fine particles (manufactured by Ishihara Sangyo Co., Ltd .: CR97) 2 parts Tetrahydrofuran 40 parts Cyclohexane 140 parts

(Example 7)
In the same manner as in Reference Example 7 , an undercoat layer was formed on an aluminum plate support, and then a mixture having the following composition was pulverized and mixed in a ball mill, and the resulting dispersion was placed on the undercoat layer with a wet gap of about 35 μm. Was applied with a doctor blade and naturally dried to form a charge generation layer. Further, a coating solution for the first charge transport layer having the following composition is applied onto the charge generation layer with a doctor blade, dried at 80 ° C. for 2 minutes, and then at 130 ° C. for 20 minutes, and the first charge transport layer having a thickness of about 20 μm. A layer was formed. Next, a coating solution for the second charge transport layer having the following composition was applied onto the first charge transport layer with a doctor blade, dried at 80 ° C. for 2 minutes, and then at 130 ° C. for 20 minutes to give a second about 5 μm thick second solution. A charge transport layer was formed to prepare a photoreceptor.

[Coating liquid for charge generation layer]
Y-type oxotitanium phthalocyanine 1.5 parts Polyester resin [Toyobo Co., Ltd .: Byron 200] 1 part Dichloromethane 100 parts

[Coating liquid for first charge transport layer]
Charge transport material represented by the structural formula (e) 7 parts Polycarbonate resin [manufactured by Teijin: Panlite C-1400] 10 parts Tetrahydrofuran 100 parts

[Coating liquid for second charge transport layer]
Charge transport material represented by the structural formula (e) 3 parts Polycarbonate resin represented by the following structural formula (f) (weight average molecular weight: 116300) 5 parts Titanium oxide fine particles (manufactured by Ishihara Sangyo Co., Ltd .: CR97) 2 parts Tetrahydrofuran 40 parts cyclohexane 140 parts

(Reference Example 1)
A photoconductor was produced in the same manner as in Reference Example 7 except that the charge transport material of Reference Example 7 was changed to a butadiene compound represented by the following structural formula (g).

(Reference Example 2)
A photoconductor was produced in the same manner as in Example 7 except that the charge transport material of Example 7 was changed to the butadiene compound represented by the structural formula (g).

The charge transport layer film alone was formed in the same manner on the polyester film using the charge transport layer coating liquids of Example 7, Reference Examples 1-2 and Reference Examples 7-9 . The charge transport layer film was peeled off from the polyester film, the transmission spectrum of the obtained charge transport layer film was measured with a spectrophotometer, and the transmittance at each wavelength was determined from the above formula (B). The results are shown in Table 1.

The obtained electrophotographic photosensitive member was measured for spectral sensitivity in a short wavelength LD of 400 to 450 nm and an LED oscillation wavelength range with EPA-8100 (manufactured by Kawaguchi Electric Manufacturing Co., Ltd.). A xenon lamp was used as a light source, and spectroscopy was performed using a monochromator (Nikon Corp.). First, the photosensitive member is charged to −800 (V) or more by corona discharge, and then the charging is stopped, exposure is performed with each monochromatic light, and the time required for the surface potential to be from −800 (V) to −100 (V). The exposure dose (μJ / cm ² ) was calculated from the irradiation light intensity (μW / cm ² ) at each wavelength. The light attenuation potential difference 700 (V) at this time was divided by the exposure amount, and the obtained value was defined as a spectral sensitivity value (V · cm ² / μJ). However, since the potential decrease due to dark decay is included when light decays, the dark decay amount of each photoconductor is measured before the photosensitivity measurement, and each spectral sensitivity value is corrected using this value. The results are also shown in Table 1.

From Table 1, the electrophotographic photoreceptors of Reference Examples 1 and 2 provided with a charge transport layer that does not transmit monochromatic light of 400 to 450 nm in the oscillation wavelength region of the short wavelength LD or LED may not exhibit sensitivity in this region. Recognize. On the other hand, the charge transport layers of Example 7 and Reference Examples 7 to 9 all show good light transmission characteristics in this region, and it can be seen that the electrophotographic photosensitive member has high sensitivity.

(Comparative Example 2)
Resin No. used in the charge transport layer coating solution of Reference Example 7 A photoconductor was prepared in the same manner as in Reference Example 7 except that the polyurethane resin No. 3 (weight average molecular weight: 12900) was changed to a polycarbonate resin [Panlite C-1400, manufactured by Teijin Ltd.].

(Comparative Example 3)
Resin No. used in the coating solution for the second charge transport layer of Reference Example 9 was used. A photoconductor was prepared in the same manner as in Reference Example 9 except that the polyester resin No. 4 was changed to a siloxane copolymer polycarbonate resin (weight average molecular weight: 157800) represented by the following structural formula (h).

The electrophotographic photosensitive member prepared in Example 7, Reference Examples 7 to 9 and Comparative Examples 2 to 3 was used with a wearer wheel CS-5 in a Taber abrasion tester (manufactured by Toyo Seiki Co., Ltd.), and the rotational speed was 1 kg. The sample was abraded 1000 times under the condition of 60 rpm, and the weight difference between the photoreceptor sample before and after the abrasion test was defined as the abrasion amount (mg). The results are shown in Table 2. The change in contact angle with pure water before and after the Taber abrasion test on the surface of the photoreceptor was measured. The contact angle for pure water was measured by a droplet method using a contact angle meter CA-W type (manufactured by Kyowa Interface Science Co., Ltd.). The results are shown in Table 2. The sliding angle was measured with the contact angle meter at a pure water volume of 17 μl. The static friction coefficient of the photoreceptor surface was also measured using an automatic friction coefficient measuring instrument. The results are also shown in Table 2.

From Table 2, it can be seen that the electrophotographic photoreceptor of the present invention (Example 7 ) and Reference Examples 7 to 9 have a smaller wear amount than Comparative Examples 2 and 3. In particular, the abrasion resistance is remarkably improved by containing a filler in the photosensitive layer as in Example 7 and Reference Example 9 . The electrophotographic photoreceptor of the present invention maintains water repellency such that the contact angle with respect to pure water is 90 ° or more, not only in the initial stage but also after wear. On the other hand, the electrophotographic photoreceptor of Comparative Example 3 is inferior in water repellency after wear.

  As described above, the electrophotographic photoreceptor of the present invention is very excellent in mechanical durability and maintains water repellency for a long time. Further, it can be seen that the photoconductors of the examples are in a low surface energy state because the sliding angle is smaller than that of the comparative examples and the coefficient of static friction is low.

( Reference Examples 10 to 11 and Reference Example 3)
The undercoat layer coating solution, charge generation layer coating solution, and charge transport layer coating solution used in Reference Example 7 on an aluminum cylinder were sequentially applied and dried. Reference Example 10 was performed in the same manner as Reference Example 7. A multilayer photosensitive drum was prepared. The photosensitive drums of Reference Examples 11 and 3 were prepared in the same manner as in Reference Example 10 except that the photosensitive layer coating solution was changed to that in Reference Example 9 or Reference Example 1.

  The above-described electrophotographic photosensitive drum is mounted on the electrophotographic apparatus shown in FIG. 6 (however, the image exposure light source is an LD having a light emission at 405 nm (image writing by a polygon mirror)), and the photosensitivity immediately before development is performed. A surface potentiometer probe was inserted so that the body surface potential could be measured. Ten thousand sheets were printed continuously, and the surface potential of the image exposure part and the image non-exposure part at that time was measured initially and after 10,000 sheets. The results are shown in Table 3.

( Reference Example 12 )
An undercoat layer coating solution, a charge generation layer coating solution, and a charge transport layer coating solution having the following composition are applied and dried in order on an electroformed nickel belt, and the film thickness is about 6 μm. A laminated photoreceptor having a charge generation layer of about 0.3 μm, a first charge transport layer of 24 μm, and a second charge transport layer of 4 μm was prepared.

[Coating liquid for undercoat layer]
Titanium dioxide (TA-300) 5 parts Copolymer polyamide resin (Toray: CM-8000) 4 parts Methanol 50 parts Isopropanol 20 parts

[Coating liquid for charge generation layer]
Y-type oxotitanium phthalocyanine pigment powder 4 parts Polyvinyl butyral 2 parts Cyclohexanone 50 parts Tetrahydrofuran 100 parts

[Coating liquid for first charge transport layer]
Charge transport material represented by the structural formula (e) 7 parts Polycarbonate resin [manufactured by Teijin: Panlite C-1400] 10 parts Tetrahydrofuran 150 parts

[Coating liquid for second charge transport layer]
0.45 part of charge transport material represented by the structural formula (e) 0.75 part of a polycarbonate resin represented by the following structural formula (i)
(Weight average molecular weight: 198700)
Titanium oxide fine particles (Ishihara Sangyo Co., Ltd .: CR97) 0.3 parts Dichloromethane 45 parts

  The electrophotographic photosensitive belt thus produced is attached to the electrophotographic process shown in FIG. 7 (but no exposure before cleaning), and the image exposure light source is a 450 nm semiconductor laser (image writing by a polygon mirror). A surface potential meter probe was inserted so that the surface potential of the photoreceptor immediately before development could be measured. 8000 sheets were printed continuously, and the surface potential of the image exposure part and the image non-exposure part at that time was measured initially and after 8,000 sheets. The results are shown in Table 4.

( Reference Example 13 )
The aluminum cylinder surface was anodized and then sealed. On top of this, the following charge generation layer coating solution and charge transport layer coating solution are sequentially applied and dried to form a 0.2 μm thick charge generation layer, a 20 μm first charge transport layer, and a 5 μm first charge transport layer. A two-charge transport layer was formed to produce an electrophotographic photoreceptor.

[Coating liquid for charge generation layer]
τ-type metal-free phthalocyanine pigment powder 3 parts Bisazo compound represented by the structural formula (b) 3 parts Polyvinyl butyral resin (BM-S) 1 part Cyclohexanone 250 parts Methyl ethyl ketone 50 parts

[Coating liquid for first charge transport layer]
Charge transport material represented by the structural formula (e) 7 parts Polycarbonate resin [manufactured by Teijin: Panlite C-1400] 10 parts Tetrahydrofuran 150 parts

[Coating liquid for second charge transport layer]
7 parts of charge transport material represented by the structural formula (e) 10 parts of polycarbonate resin represented by the following structural formula (j)
(Weight average molecular weight: 183700)
Alumina fine particles (Alumina-C manufactured by Nippon Aloezil) 4 parts Dichloromethane 80 parts

  The electrophotographic photosensitive member thus produced was mounted on the electrophotographic process cartridge shown in FIG. 8 and then mounted on the image forming apparatus. However, a surface electrometer probe was inserted so that the image exposure light source was a semiconductor laser having an oscillation wavelength of 435 nm (image writing by a polygon mirror) so that the surface potential of the photoconductor immediately before development could be measured. Five thousand sheets were printed continuously, and the surface potentials of the image exposed part and the image non-exposed part at that time were measured initially and after 5,000 sheets. The results are shown in Table 5.

Further, the electrophotographic photosensitive member of Reference Examples 10 to 13 , an optical system in which a charging roller as a charging unit, a semiconductor laser having an oscillation wavelength of 405 nm as a light source as an image exposure unit, and a beam diameter can be adjusted by an aperture, and two-component development as a developing unit An isolated dot obtained with a beam diameter of 30 μm was formed on the photosensitive member by an imaging experiment machine equipped with a unit and a pattern generator, transferred to an adhesive tape, read by a CCD camera, and image analysis was performed. The initial charging potential of the photoconductor was 600V, and magnetic toner having an average particle diameter of 6 μm was used. When the shape and reproducibility of the isolated dots were evaluated visually, the dots were formed and reproduced with good contrast in any of the photoreceptors of Reference Examples 10 to 13 .

It is a schematic diagram of the transmission spectrum of a charge transport layer. 1 is a schematic cross-sectional view of one electrophotographic photosensitive member of the present invention. It is a schematic sectional drawing of the other electrophotographic photoreceptor of this invention. It is a schematic sectional drawing of the other electrophotographic photoreceptor of this invention. 2 is a schematic cross-sectional view of still another electrophotographic photosensitive member of the present invention. FIG. 1 is a schematic view of an electrophotographic apparatus and a process cartridge for an electrophotographic apparatus according to the present invention. It is the schematic of the other electrophotographic apparatus of this invention. FIG. 2 is a schematic diagram illustrating an example of a process cartridge for an electrophotographic apparatus according to the present invention.

Explanation of symbols

1 Conductive Support 2 ′, 2 ″, 2 ′ ″, 2 ″ ″ Photosensitive Layer 3 Charge Generating Material 4 Charge Transport Layer (or Charge Transport Medium)
4-1 First Charge Transport Layer 4-2 Second Charge Transport Layer 5 Charge Generation Layer 6 Protective Layer 7 Electrophotographic Photoreceptor 8 Charge Charger 9 Pre-Transfer Charger 10 Transfer Charger 11 Separation Charge 12 Charger Before Cleaning 13 Image Exposure Portion 14 Static elimination lamp 15 Development unit 16 Transfer paper 17 Fur brush 18 Cleaning brush 21 Electrophotographic photosensitive member 22, 22a, 22b, driving roller 23 Charger 24, 26, 28 Light source 29 Electrophotographic photosensitive member 30 Charging charger 31 Cleaning brush 32 Image exposure unit 33 Developing roller

Claims (20)

On a conductive support, a photosensitive layer containing at least represented by the following structural formula (f) Lupolen polycarbonate resin, copolymerization ratio of the polycarbonate resin represented by the structural formula (f) n: m is An electrophotographic photoreceptor having a ratio of 0.5: 0.5 .
Said photosensitive layer comprises at least two layers of a charge transport layer containing a reportage polycarbonate resin represented by the structural formula as a charge generating layer and a charge transport material containing a charge-generating material (f), and the charge generation layer 2. The electrophotographic photosensitive member according to claim 1, wherein the charge transport layer and the charge transport layer are provided on the conductive support in this order. The charge transport layer, on the first charge transport layer containing a charge-transporting material, the second charge transport layer containing a charge-transporting substance represented by at least the formula (f) Lupolen polycarbonate resin The electrophotographic photosensitive member according to claim 2, wherein the electrophotographic photosensitive member has a laminated structure in which are sequentially provided.   4. The electrophotographic photosensitive member according to claim 2, wherein the charge transport layer transmits monochromatic light in a wavelength range of 390 to 460 nm.   5. The electrophotographic photosensitive member according to claim 4, wherein the charge transport layer exhibits a transmittance of 50% or more for monochromatic light in a wavelength range of 390 to 460 nm. On a conductive support a photosensitive layer, further an electrophotographic characterized in that a protective layer containing at least represented by the structural formula (f) of claim 1 Lupo polycarbonate resin thereon Photoconductor. The electrophotographic photosensitive member according to any one of claims 1 to 6, characterized in that the layer containing the represented by structural formula (f) Lupolen polycarbonate resin and further contain a filler.   Filler is titanium oxide, tin oxide, zinc oxide, zirconium oxide, indium oxide, silicon nitride, calcium oxide, barium sulfate, silica, colloidal silica, alumina, carbon black, fluorine resin fine powder, polysiloxane resin fine powder, 8. The electrophotographic photosensitive member according to claim 7, wherein the electrophotographic photosensitive member is at least one selected from polyethylene resin fine powder and a graft copolymer having a core-shell structure.   9. The electrophotographic photosensitive member according to claim 1, wherein a contact angle with respect to pure water on the surface of the electrophotographic photosensitive member is 85 ° or more and 140 ° or less.   10. The contact angle of the photosensitive layer to pure water at a position 1 ± 0.3 μm away from the outermost surface of the electrophotographic photosensitive member toward the support is 85 ° or more and 140 ° or less. An electrophotographic photoreceptor according to any one of the above.   The electrophotographic photosensitive member according to any one of claims 1 to 10, wherein a sliding angle with respect to pure water on the surface of the electrophotographic photosensitive member is 5 ° or more and 65 ° or less.   An electrophotographic method, wherein charging, image exposure, development and transfer are performed using the electrophotographic photosensitive member according to claim 1.   13. The electrophotographic method according to claim 12, wherein the beam spot diameter of the writing light source in image exposure is 10 to 30 [mu] m.   14. The electrophotographic method according to claim 12, wherein a semiconductor laser or a light emitting diode having an oscillation wavelength in the range of 400 to 450 nm is used as a writing light source in image exposure.   An electrophotographic apparatus comprising the electrophotographic photosensitive member according to claim 1, and further comprising a charging unit, an image exposing unit, a developing unit, and a transfer unit.   16. The electrophotographic apparatus according to claim 15, wherein the beam spot diameter of the writing light source in the image exposure means is 10 to 30 [mu] m.   17. The electrophotographic apparatus according to claim 15, wherein the writing light source in the image exposure means is a semiconductor laser or a light emitting diode having an oscillation wavelength in the range of 400 to 450 nm.   An electrophotographic photosensitive member according to any one of claims 1 to 11, and at least one means selected from a charging means, an image exposure means, a developing means, a transfer means, and a cleaning means, are integrally formed to form an electrophotographic A process cartridge for an electrophotographic apparatus, which is detachable from an apparatus main body.   19. The process cartridge for an electrophotographic apparatus according to claim 18, wherein the beam spot diameter of the writing light source in the image exposure means is 10 to 30 [mu] m. 20. The process cartridge for an electrophotographic apparatus according to claim 18, wherein the writing light source in the image exposure means is a semiconductor laser or a light emitting diode having an oscillation wavelength in the range of 400 to 450 nm.