JP2011107462A - Electrophotographic photoreceptor, process cartridge, and electrophotographic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor in which electric potential change is prevented when used for a short time even after the electrophotographic photoreceptor is repeatedly used for a long time. <P>SOLUTION: There is provided an electrophotographic photoreceptor, wherein an intermediate layer includes: a fullerene derivative with a metal oxide particle, organic resin, and hydroxy group. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an electrophotographic photosensitive member, and a process cartridge and an electrophotographic apparatus having the electrophotographic photosensitive member.

  In recent years, an electrophotographic photosensitive member having an intermediate layer containing an inorganic compound and a photosensitive layer containing a charge generating material and a charge transporting material provided on the intermediate layer as an electrophotographic photosensitive member used in an electrophotographic apparatus. (Organic electrophotographic photoreceptor) is used.

  The potential characteristics (chargeability and sensitivity) of the electrophotographic photosensitive member depend on the types of materials used for the intermediate layer and the photosensitive layer. In particular, metal oxides, organic compounds, and binder resins used for the intermediate layer are materials that greatly influence the potential characteristics of the electrophotographic photosensitive member. Therefore, it has been found that the potential characteristics of the electrophotographic photosensitive member can be improved by the structure and combination of the above materials.

With the recent increase in the speed of electrophotographic devices (higher process speed), it is of course possible to improve the potential characteristics such as improved charging properties and higher sensitivity. It is also an issue to further suppress changes in sex and sensitivity. Specifically, it is a problem to further suppress potential fluctuations (change in chargeability, change in sensitivity) from the viewpoints of (1) and (2) below.
(1) Repeated use over a long period from the start of use of the electrophotographic photosensitive member to the end of the life of the electrophotographic photosensitive member, and
(2) Repetitive use for a short period of time (for example, from the start of image output to the first continuous output of about 1000 sheets) in a relatively short period of time From the viewpoint of (1) above, potential fluctuations may occur depending on the configuration of the electrophotographic photosensitive member. In some cases, the potential becomes large (the potential characteristic is greatly deteriorated). In such a case, even if the electrophotographic photosensitive member is left after repeated use for a long period of time, it does not return to the potential characteristics at the start of use, and it can be said that the recoverability is small.

  On the other hand, if the potential fluctuation is large from the viewpoint of (2) above, for example, the color of the output first sheet image and the 1000th sheet may change. However, such a short-term potential fluctuation can be easily recovered in a relatively short time to the potential characteristics at the start of use by leaving the electrophotographic photosensitive member.

  Then, it is considered that accumulation of potential fluctuations that cannot be recovered in a short time even if left in the above (2) leads to potential fluctuations in the above (1).

  For an electrophotographic photoreceptor, it is important to suppress potential fluctuations in the above points (1) and (2) and to always output a stable image. What is particularly problematic is the potential fluctuation from the viewpoint of the above (2), and it is strongly required that the change in color is small in any situation.

  That is, the potential fluctuation in the above (2) is suppressed at the very initial stage of use of the electrophotographic photosensitive member, or the potential fluctuation in the above (2) is observed even after the electrophotographic photosensitive member is repeatedly used for a long time. It is required to be suppressed.

  In response to such a requirement, Patent Document 1 discloses a technique for suppressing potential fluctuation by providing an acceptor compound (organic compound) to a metal oxide as a material constituting an intermediate layer of an electrophotographic photosensitive member. Has been. Patent Document 2 discloses a technique for suppressing potential fluctuation by arranging a dye (organic compound) having light absorption between 450 and 950 nm on the surface of a metal oxide. However, neither is paying attention to the potential fluctuation in the viewpoint of (2).

  Patent Document 3 discloses an intermediate layer composed of a mixed system of an organometallic compound such as an organozirconium compound, an electron accepting compound (organic compound), and a binder resin. It is unclear as to the potential fluctuation in the viewpoint.

JP 2006-030700 A JP 2004-219904 A JP 09-197701 A

  In the electrophotographic photoreceptors disclosed in Patent Documents 1 to 3, the potential fluctuation (above (2)) when used for a short period of time was small at the very early stage of use of the electrophotographic photoreceptor. However, when these electrophotographic photoreceptors are repeatedly used for a long time (above (1)) and then are used again for a short period, the potential fluctuation (above (2)) is seen. It became clear that there was a phenomenon that it was larger than that.

  In addition, even if the amount of potential fluctuation in repeated use over a long period is large or small, if you look at the amount of potential fluctuation when used for a short period after that, it is larger than the amount of potential fluctuation when used for a short period after the initial measurement. I also found out that

  An object of the present invention is to provide an electrophotographic photosensitive member in which potential fluctuations when used for a short period even after repeated use for a long period are suppressed.

  Another object of the present invention is to provide a process cartridge and an electrophotographic apparatus having the electrophotographic photosensitive member.

The present invention relates to an electrophotographic photoreceptor having a support, an intermediate layer provided on the support, and a photosensitive layer provided on the intermediate layer.
The intermediate layer contains metal oxide particles, an organic resin, and a fullerene derivative having a hydroxy group.

  According to the present invention, it is possible to provide an electrophotographic photosensitive member in which potential fluctuations when used for a short period even after repeated use for a long period are suppressed.

  Further, according to the present invention, a process cartridge and an electrophotographic apparatus having the electrophotographic photosensitive member can be provided.

1 is a diagram illustrating an example of a schematic configuration of an electrophotographic apparatus including a process cartridge having the electrophotographic photosensitive member of the present invention.

  The present invention is characterized in that the intermediate layer of the electrophotographic photoreceptor contains metal oxide particles, an organic resin, and a fullerene derivative having a hydroxy group (—OH).

  Although the details of the reason that the potential fluctuation is improved when the fullerene derivative having a hydroxy group is contained in the intermediate layer for a long period of time and then used for a short period of time have not been fully elucidated, the present inventors Guesses as follows.

  That is, the present inventors presume that the fullerene derivative having a hydroxy group interacts with the metal oxide particles, thereby easily receiving electrons. For example, it is presumed that electrons are attracted from metal oxide particles to facilitate the transfer of electrons between the metal oxide particles. Furthermore, it is speculated that it also supports the reception of electrons from the photosensitive layer (charge generation layer).

Examples of the fullerene derivative having a hydroxy group used in the present invention include fullerenol (C ₆₀ ) (trade name) manufactured by Honjo Chemical Co., Ltd., nano spectra D100 (trade name) manufactured by Frontier Carbon Co., Ltd., and ATR (trade name). C ₆₀ (OH) ₆ water-soluble fullerenes, C ₆₀ (OH) _22-26 water-soluble fullerenes, C ₆₀ (OH) ₂₄ water-soluble fullerenes, etc. manufactured by Co., Ltd. are mentioned, but the present invention is limited to these. is not.

Among these, fullerenol (C ₆₀ ) and nano spectra D100 are preferable, and fullerenol (C ₆₀ ) is more preferable.

  Moreover, in this invention, it is preferable that an intermediate | middle layer contains 0.05 to 4.00 mass% of fullerene derivatives which have a hydroxy group with respect to metal oxide particle. If it is 0.05 mass% or more, the effect of suppressing the fluctuation | variation of the charge by interaction with a metal oxide particle will become large. If it is 4.00 mass% or less, it is thought that the interaction between fullerene derivatives can be suppressed, and as a result, the said effect becomes large.

  Moreover, in this invention, it is preferable that an intermediate | middle layer contains 10 mass% or more and 50 mass% or less of organic resin with respect to metal oxide particle. If it is 10 mass% or less, it becomes difficult to produce a crack in the surface of an intermediate | middle layer, and electric potential stability increases. If it is 50 mass% or less, the distance between the metal oxide particles interacting with the fullerene derivative in the intermediate layer is reduced, and the degree of electron flow increases, so that the effect of suppressing potential fluctuation is increased.

  In the present invention, the metal oxide particles contained in the intermediate layer include particles such as titanium oxide, zinc oxide, tin oxide, zirconium oxide, and aluminum oxide. The metal oxide particles may be particles in which the surface of the metal oxide is treated with a surface treatment agent such as a silane coupling agent. Among the metal oxide particles, zinc oxide particles are preferable because they have a large effect of suppressing fluctuations in charging.

  In the present invention, examples of the organic resin contained in the intermediate layer include acrylic resins, allyl resins, alkyd resins, ethyl cellulose resins, ethylene-acrylic acid copolymers, epoxy resins, casein resins, silicone resins, gelatin resins, and phenols. Resin, butyral resin, polyacrylate resin, polyacetal resin, polyamideimide resin, polyamide resin, polyallyl ether resin, polyimide resin, polyurethane resin, polyester resin, polyethylene resin, polycarbonate resin, polystyrene resin, polysulfone resin, polyvinyl alcohol resin, polybutadiene Examples thereof include resins and polypropylene resins. Among these, a polyamide resin and a polyurethane resin are preferable because they have a great effect of suppressing fluctuations in charging.

  The electrophotographic photoreceptor of the present invention is an electrophotographic photoreceptor having a support, an intermediate layer provided on the support, and a photosensitive layer provided on the intermediate layer. Preferably, an electrophotographic photosensitive member having a multilayer type photosensitive layer having a charge generation layer provided on the intermediate layer and a charge transport layer provided on the charge generation layer as the photosensitive layer.

  As a support body, what is necessary is just to have electroconductivity (electroconductive support body), For example, metal (alloy-made) support bodies, such as aluminum, aluminum alloy, and stainless steel, can be used. Moreover, the said metal support body and plastic support body which have a layer in which aluminum, an aluminum alloy, an indium oxide tin oxide alloy etc. were formed into a film by vacuum deposition can also be used. Also, use is made of a support in which conductive particles such as carbon black, tin oxide particles, titanium oxide particles, and silver particles are impregnated into plastic or paper together with an appropriate binder resin, or a plastic support having a conductive binder resin is used. You can also In addition, examples of the shape of the support include a cylindrical shape and a belt shape, and a cylindrical shape is preferable.

  Further, the surface of the support may be subjected to a cutting process, a roughening process, or an alumite process for the purpose of preventing interference fringes due to scattering of laser light.

  Between the support and the photosensitive layer (charge generation layer, charge transport layer) or the intermediate layer of the present invention, there is a conductive layer for the purpose of preventing interference fringes due to scattering of laser light and covering scratches on the support. It may be provided. The conductive layer can be formed by dispersing carbon black and conductive particles in a binder resin. The thickness of the conductive layer is preferably 5 to 40 μm, more preferably 10 to 30 μm.

  The intermediate layer is provided between the support or conductive layer and the photosensitive layer (charge generation layer, charge transport layer).

  In the present invention, the intermediate layer coating solution for forming the intermediate layer may be an intermediate layer coating solution obtained by dispersing metal oxide particles and a fullerene derivative having a hydroxy group together with an organic resin and a solvent. Alternatively, an intermediate layer coating solution obtained by adding a solution obtained by dissolving an organic resin to a dispersion obtained by dispersing metal oxide particles and a fullerene derivative having a hydroxy group together with a solvent, and further dispersing the solution. Good. The intermediate layer of the electrophotographic photoreceptor of the present invention can be formed by applying a coating solution obtained by these methods and drying it. Examples of the dispersion method include a method using a homogenizer, an ultrasonic disperser, a ball mill, a sand mill, a roll mill, a vibration mill, an attritor, and a liquid collision type high-speed disperser.

  The solvent used in the intermediate layer coating solution is preferably selected from the viewpoints of the organic resin used and dispersion stability. Examples of the organic solvent include alcohols, sulfoxides, ketones, ethers, esters, aliphatic halogenated hydrocarbons, and aromatic compounds.

  The intermediate layer of the electrophotographic photoreceptor of the present invention may contain organic resin fine particles and a leveling agent as necessary.

  The thickness of the intermediate layer is preferably 0.5 to 20 μm, more preferably 0.6 to 5 μm, from the viewpoint of suppressing fluctuations in charging.

  Examples of the charge generation material include azo pigments such as monoazo, disazo, and trisazo, phthalocyanine pigments such as metal phthalocyanine and nonmetal phthalocyanine, indigo pigments such as indigo and thioindigo, and perylene pigments such as perylene anhydride and perylene imide, , Anthraquinone, pyrenequinone, dibenzpyrenequinone and other polycyclic quinone pigments, squarylium dyes, pyrylium salts and thiapyrylium salts, triphenylmethane dyes, inorganic substances such as selenium, selenium-tellurium and amorphous silicon, and quinacridone pigments And cyanine dyes such as azulenium salt pigments, quinocyanine, anthanthrone pigments, pyranthrone pigments, xanthene dyes, quinoneimine dyes, styryl dyes, cadmium sulfide , And zinc oxide. These charge generation materials may be used alone or in combination of two or more.

  Among these charge generation materials, phthalocyanine pigments and azo pigments are preferable from the viewpoint of sensitivity, and phthalocyanine pigments are more preferable.

  Among phthalocyanine pigments, oxytitanium phthalocyanine, chlorogallium phthalocyanine, and hydroxygallium phthalocyanine exhibit excellent charge generation efficiency.

  Further, among the hydroxygallium phthalocyanines, from the viewpoint of potential characteristics, a crystal form having strong peaks at Bragg angles 2θ of 7.4 ° ± 0.3 ° and 28.2 ° ± 0.3 ° in CuKα characteristic X-ray diffraction The hydroxygallium phthalocyanine crystal is more preferable.

  In the present invention, X-ray diffraction was measured using CuKα rays under the following conditions.

Measuring instrument used: Fully automatic X-ray diffractometer MXP18, manufactured by Mac Science
X-ray tube: Cu
Tube voltage: 50 kV
Tube current: 300mA
Scan method: 2θ / θ scan Scan speed: 2 deg. / Min
Sampling interval: 0.020 deg.
Start angle (2θ): 5 deg.
Stop angle (2θ): 40 deg.
Divergence slit: 0.5 deg.
Scattering slit: 0.5 deg.
Receiving slit: 0.3 deg.
Curved monochromator used When the photosensitive layer is a laminated type, examples of the binder resin used for the charge generation layer include acrylic resin, allyl resin, alkyd resin, epoxy resin, diallyl phthalate resin, styrene-butadiene copolymer, butyral resin , Benzal resin, polyacrylate resin, polyacetal resin, polyamideimide resin, polyamide resin, polyallyl ether resin, polyarylate resin, polyimide resin, polyurethane resin, polyester resin, polyethylene resin, polycarbonate resin, polystyrene resin, polysulfone resin, polyvinyl acetal Examples thereof include resins, polybutadiene resins, polypropylene resins, methacryl resins, urea resins, vinyl chloride-vinyl acetate copolymers, vinyl acetate resins, and vinyl chloride resins. Among these, a butyral resin is particularly preferable. These may be used alone or in combination as a mixture or copolymer.

  The charge generation layer can be formed by applying a charge generation layer coating solution obtained by dispersing a charge generation material together with a binder resin and a solvent and drying the coating solution. Examples of the dispersion method include a method using a homogenizer, an ultrasonic disperser, a ball mill, a sand mill, a roll mill, a vibration mill, an attritor, and a liquid collision type high-speed disperser. The ratio of the charge generation material and the binder resin is preferably in the range of 0.3: 1 to 10: 1 by mass ratio.

  The solvent used in the charge generation layer coating solution is preferably selected from the solubility and dispersion stability of the binder resin and charge generation material used. Examples of the organic solvent include alcohols, sulfoxides, ketones, ethers, esters, aliphatic halogenated hydrocarbons, and aromatic compounds.

  The thickness of the charge generation layer is preferably 5 μm or less, and more preferably 0.1 μm or more and 2 μm or less. In addition, various sensitizers, antioxidants, ultraviolet absorbers, and plasticizers can be added to the charge generation layer as necessary.

  Examples of the charge transport material include triarylamine compounds, hydrazone compounds, styryl compounds, stilbene compounds, and butadiene compounds. Among these, a triarylamine compound is preferable from the viewpoint of high charge mobility.

  When the photosensitive layer is a laminated type, examples of the binder resin used for the charge transport layer include acrylic resin, acrylonitrile resin, allyl resin, alkyd resin, epoxy resin, silicone resin, phenol resin, phenoxy resin, and polyacrylamide resin. , Polyamideimide resin, polyamide resin, polyallyl ether resin, polyarylate resin, polyimide resin, polyurethane resin, polyester resin, polyethylene resin, polycarbonate resin, polysulfone resin, polyphenylene oxide resin, polybutadiene resin, polypropylene resin, methacrylic resin, etc. It is done. In particular, polyarylate resin and polycarbonate resin are preferable. These may be used alone or in combination as a mixture or copolymer.

  The charge transport layer can be formed by applying a charge transport layer coating solution obtained by dissolving a charge transport material and a binder resin in a solvent and drying it. The ratio of the charge transport material and the binder resin is preferably in the range of 0.3: 1 to 10: 1 by mass ratio. From the viewpoint of preventing cracks, the drying temperature is preferably 60 ° C. or higher and 150 ° C. or lower, and more preferably 80 ° C. or higher and 120 ° C. or lower. The drying time is preferably 10 minutes or more and 60 minutes or less.

  Examples of the solvent used in the charge transport layer coating solution include alcohols such as propanol and butanol (particularly alcohols having 3 or more carbon atoms), aromatic hydrocarbons such as anisole, toluene, xylene, and chlorobenzene, methylcyclohexane, and ethyl. Cyclohexane or the like is used.

  When the charge transport layer has a laminated structure, the charge transport layer on the surface side of the electrophotographic photosensitive member has a chain transporting functional group in order to increase the mechanical strength of the electrophotographic photosensitive member. It is preferable to form a layer obtained by curing by polymerizing and / or crosslinking. Examples of the chain polymerizable functional group include an acrylic group, an alkoxysilyl group, and an epoxy group. In order to polymerize and / or crosslink a charge transport material having a chain polymerizable functional group, heat, light, radiation (electron beam or the like) can be used.

  When the charge transport layer of the electrophotographic photoreceptor is one layer, the thickness of the charge transport layer is preferably 5 μm or more and 40 μm or less, and more preferably 8 μm or more and 30 μm or less.

  The thickness of the charge transport layer on the support side of the electrophotographic photosensitive member when the charge transport layer has a laminated structure is preferably 5 μm or more and 30 μm or less. For the charge transport layer on the surface side of the electrophotographic photosensitive member, It is preferable that they are 1 micrometer or more and 10 micrometers or less.

  In addition, an antioxidant, an ultraviolet absorber, a plasticizer, and the like can be added to the charge transport layer as necessary.

  A protective layer for the purpose of protecting the photosensitive layer may be provided on the photosensitive layer. The protective layer can be formed by applying a protective layer coating solution obtained by dissolving the various binder resins described above in a solvent and drying the coating solution. Moreover, you may form a protective layer by apply | coating the coating liquid for protective layers obtained by dissolving a resin monomer or an oligomer in a solvent, and hardening and / or drying this. For curing, light, heat, or radiation (such as an electron beam) can be used.

  The thickness of the protective layer is preferably 0.5 μm or more and 10 μm or less, and particularly preferably 1 μm or more and 7 μm or less. Moreover, electroconductive particle etc. can also be added to a protective layer as needed.

  When applying the coating liquid for each of the above layers, for example, a coating method such as a dip coating method (dip coating method), a spray coating method, a spinner coating method, a roller coating method, a Meyer bar coating method, a blade coating method, or the like should be used. Can do.

  Further, the outermost layer (surface layer) of the electrophotographic photosensitive member may contain a lubricant such as silicone oil, wax, polytetrafluoroethylene particles, silica particles, alumina particles, and boron nitride.

  FIG. 1 shows a schematic configuration of an electrophotographic apparatus provided with a process cartridge having the electrophotographic photosensitive member of the present invention.

  In FIG. 1, a cylindrical electrophotographic photosensitive member 1 of the present invention is rotationally driven with a predetermined peripheral speed (process speed) in the direction of an arrow about an axis 2. The surface of the electrophotographic photosensitive member 1 is uniformly charged with a predetermined positive or negative potential by a charging unit 3 (primary charging unit: charging roller or the like) during the rotation process. Next, exposure light 4 intensity-modulated in response to time-series electric digital image signals of target image information output from exposure means (not shown) such as slit exposure or laser beam scanning exposure, which is reflected light from the document. Receive. In this way, electrostatic latent images corresponding to target image information are sequentially formed on the surface of the electrophotographic photosensitive member 1.

  The electrostatic latent image formed on the surface of the electrophotographic photoreceptor 1 is then visualized by regular development or reversal development with charged particles (toner) contained in the developer in the developing means 5 to become a toner image. Next, the toner image formed and supported on the surface of the electrophotographic photosensitive member 1 is sequentially transferred onto the transfer material P by the transfer bias from the transfer unit 6 (transfer roller or the like). Here, the transfer material P is taken out from the transfer material supply means (not shown) in synchronism with the rotation of the electrophotographic photosensitive member 1 and is placed between the electrophotographic photosensitive member 1 and the transfer means 6 (contact portion). Be fed. Further, a bias voltage having a polarity opposite to the charge held in the toner is applied to the transfer means 6 from a bias power source (not shown).

  The transfer material P that has received the transfer of the toner image (in the case of the final transfer material (paper, film, etc.)) is separated from the surface of the electrophotographic photosensitive member and conveyed to the fixing means 8 to undergo the toner image fixing process. As a result, the image is printed out as an image formed product (print, copy). When the transfer material P is an intermediate transfer member or the like, it is printed after receiving a fixing process after a plurality of transfer processes.

  The surface of the electrophotographic photosensitive member 1 after the transfer of the toner image is cleaned by a cleaning means 7 (cleaning blade or the like) to remove deposits such as a transfer residual developer (transfer residual toner). In recent years, a cleanerless system has also been studied, and transfer residual toner can be directly collected by a developing device or the like. Further, the surface of the electrophotographic photoreceptor 1 is subjected to charge removal processing by pre-exposure light (not shown) from pre-exposure means (not shown), and then repeatedly used for image formation. As shown in FIG. 1, when the charging unit 3 is a contact charging unit using a charging roller or the like, pre-exposure is not necessarily required.

  In the present invention, among the above-described components such as the electrophotographic photosensitive member 1, the charging unit 3, the developing unit 5, and the cleaning unit 7, a plurality of components are housed in a container and integrally combined as a process cartridge. Also good. The process cartridge may be configured to be detachable from an electrophotographic apparatus main body such as a copying machine or a laser beam printer. For example, at least one of the charging unit 3, the developing unit 5 and the cleaning unit 7 is integrally supported together with the electrophotographic photosensitive member 1 to form a cartridge, and is detachable from the apparatus main body using a guide unit 10 such as a rail of the apparatus main body. A simple process cartridge 9.

  The exposure light 4 is reflected light or transmitted light from the original when the electrophotographic apparatus is a copying machine or a printer. Alternatively, the light is irradiated by scanning a laser beam, driving an LED array, driving a liquid crystal shutter array, or the like performed by reading a document with a sensor and converting the signal into a signal.

  The electrophotographic photosensitive member of the present invention can be applied not only to an electrophotographic copying machine but also to general electrophotographic apparatuses such as a laser beam printer, an LED printer, a FAX, and a liquid crystal shutter printer. Furthermore, the present invention can be widely applied to apparatuses such as a display, recording, light printing, plate making and facsimile using electrophotographic technology.

  Hereinafter, the present invention will be described in more detail with reference to specific examples. However, the present invention is not limited to these. In the examples, “part” means “part by mass”.

Example 1
50 parts of titanium oxide particles coated with tin oxide containing 10% antimony oxide, 25 parts of resol type phenol resin, 20 parts of methyl cellosolve, 5 parts of methanol and silicone oil (polydimethylsiloxane / polyoxyalkylene copolymer, average 0.002 parts of molecular weight 3000) were dispersed for 2 hours in a sand mill apparatus using glass beads having a diameter of 0.8 mm. Thereafter, 3.8 parts of spherical silicone resin powder (trade name: Tospearl 120 manufactured by Toshiba Silicone Co., Ltd.) were mixed and stirred for 5 hours to prepare a coating solution for a conductive layer. A conductive layer having a film thickness of 20 μm is obtained by dip-coating this conductive layer coating solution on an aluminum cylinder (a drawing tube having a diameter of 30 mm and a length of 357.5 mm) as a support and drying at 140 ° C. for 30 minutes. Formed.

  Next, an intermediate layer coating solution was prepared by the following method.

  The following materials were mixed and dispersed in a paint shaker for 15 hours using 60 parts of zirconia beads having a diameter of 0.3 mm to obtain an intermediate layer coating solution.

Metal oxide particles: Titanium oxide (trade name: TKP-101, manufactured by Teika Co., Ltd.) 4 parts Organic resin solution: N-methoxymethylated 6 nylon resin (trade name: Toresin EF-30T, manufactured by Nagase ChemteX, Methoxy (Methylation rate: 28 to 33% by mass) 10 parts dissolved in 90 parts of methanol and adjusted. 30.8 parts (of which, N-methoxymethylated 6 nylon resin is 3.08 parts, 77% by mass based on metal oxide particles)
Fullerene derivative having a hydroxy group: Fullerenol (C ₆₀ ) (Honjo Chemical Co., Ltd.) 0.0016 parts (0.04% by mass based on metal oxide particles)
Solvent: 14 parts of 1-butanol This intermediate layer coating solution was dip coated on the conductive layer and dried at 100 ° C. for 10 minutes to form an intermediate layer having a thickness of 1.2 μm.

  Next, 4 parts of a crystalline hydroxygallium phthalocyanine crystal having a strong peak at Bragg angles 2θ of 7.4 ° ± 0.3 ° and 28.2 ° ± 0.3 ° in CuKα characteristic X-ray diffraction and the following formula ( 0.04 parts of the compound represented by A)

Were added to a solution obtained by dissolving 2 parts of polyvinyl butyral resin (trade name: ESREC BX-1, manufactured by Sekisui Chemical Co., Ltd.) in 100 parts of cyclohexanone. Then, the dispersion | distribution process was carried out for 1 hour by the sand mill apparatus using the glass bead of diameter 1mm in 23 +/- 3 degreeC atmosphere, and the coating liquid for charge generation layers was prepared by adding 100 parts of ethyl acetate after a dispersion process. This charge generation layer coating solution was dip-coated on the intermediate layer and dried at 90 ° C. for 10 minutes to form a charge generation layer having a thickness of 0.21 μm.

  Next, 50 parts of an amine compound represented by the following formula (B),

50 parts of an amine compound represented by the following formula (C),

Then, 100 parts of polycarbonate resin (trade name: Iupilon Z400, manufactured by Mitsubishi Gas Chemical Co., Ltd.) was dissolved in a mixed solvent of 650 parts of chlorobenzene and 150 parts of methylal to prepare a coating solution for a charge transport layer. The charge transport layer coating solution, which has been allowed to stand for 1 day after the solution becomes uniform, is dip coated on the charge generation layer and dried at 110 ° C. for 60 minutes, whereby a first charge having a thickness of 18 μm is obtained. A transport layer was formed.

  Next, 45 parts of a compound having a structure represented by the following formula (D) (a charge transport material having an acrylic group which is a chain polymerizable functional group),

Then, 55 parts of n-propanol was dispersed and mixed with an ultrahigh pressure disperser to prepare a coating solution for the surface layer (second charge transport layer).

  This surface layer (second charge transport layer) coating solution is dip-coated on the first charge transport layer and dried for 5 minutes at 50 ° C. After drying, an electron beam is applied under the conditions of an acceleration voltage of 70 kV and an absorbed dose of 8000 Gy. Was irradiated and cured to form a surface layer (second charge transport layer). Subsequently, a heat treatment was performed for 3 minutes under the condition that the surface layer (second charge transport layer) was 120 ° C. The oxygen concentration from the electron beam irradiation to the heat treatment for 3 minutes was 20 ppm. Next, heat treatment was performed in the atmosphere for 30 minutes under the condition that the surface layer (second charge transport layer) was 100 ° C. to form a surface layer (second charge transport layer) having a thickness of 5 μm.

  Thus, an electrophotographic photosensitive member having a conductive layer, an intermediate layer, a charge generation layer, a first charge transport layer, and a surface layer (for the second charge transport layer) was produced.

(Examples 2 to 21)
In Example 1, except that the types and amounts of metal oxide particles, organic resin, and fullerene derivatives having a hydroxy group used for the preparation of the intermediate layer coating solution are as shown in Table 1, Similarly, an electrophotographic photosensitive member was produced.

“TKP-101” is a titanium oxide particle (trade name: TKP-101, crystallite diameter: 6 nm) manufactured by Teika Co., Ltd. “MZ-500” is zinc oxide particles (trade name: MZ-500, particle diameter: 20 to 30 nm) manufactured by Teika Co., Ltd. “FINEX-50” is zinc oxide particles (trade name: FINEX-50, average particle size: 20 nm) manufactured by Sakai Chemical Industry Co., Ltd. “Fullerenol C ₆₀ ” is a fullerene derivative having a hydroxy group (trade name: fullerenol (C ₆₀ )) manufactured by Honjo Chemical Co., Ltd. “Nano spectra D100” is a fullerene derivative having a hydroxy group (trade name: nano spectra D100) manufactured by Frontier Carbon Co., Ltd.

(Examples 22 to 23)
In Example 1, except that the metal oxide particles used in the preparation of the intermediate layer coating solution, the organic resin, and the type and amount of the fullerene derivative having a hydroxy group are shown in Table 2, Example 1 and Similarly, an electrophotographic photosensitive member was produced. In addition, as metal oxide particles, the surface of zinc oxide particles (trade name: MZ-500) manufactured by Teika Co., Ltd. or zinc oxide particles (trade name: FINEX-50) manufactured by Sakai Chemical Industry Co., Ltd. What gave the following silane coupling agent processes was used.

  That is, 50 parts of zinc oxide particles (trade name: MZ-500) manufactured by Teika Co., Ltd. or 50 parts of zinc oxide particles (trade name: FINEX-50) manufactured by Sakai Chemical Industry Co., Ltd., and Shinetsu as a silane coupling agent 1.5 parts of trimethoxyvinylsilane (trade name: KBM-1003) manufactured by Chemical Industry Co., Ltd. was mixed and stirred in 200 parts of toluene and reacted at room temperature for 5 hours. Thereafter, the solvent was distilled off, and vacuum drying was performed at 145 ° C. for 5 hours to obtain surface-treated zinc oxide particles.

  “MZ-500 / KBM-1003” is a trimethoxyvinylsilane (trade name: KBM-) manufactured by Shin-Etsu Chemical Co., Ltd. on the surface of zinc oxide particles (trade name: MZ-500) manufactured by Teika Co., Ltd. 1003) is subjected to a silane coupling agent treatment. "FINEX-50 / KBM-1003" is a trimethoxyvinylsilane (trade name: manufactured by Shin-Etsu Chemical Co., Ltd.) on the surface of zinc oxide particles (trade name: FINEX-50) manufactured by Sakai Chemical Industry Co., Ltd. KBM-1003) is treated with a silane coupling agent.

  The amount of the metal oxide particles used in Examples 22 and 23 shown in Table 2 in the amount of 4.12 parts is the total of trimethoxyvinylsilane and zinc oxide particles which are metal oxide particles. 12 parts and 4 parts of zinc oxide particles.

(Comparative Example 1)
In Example 13, an electrophotographic photoreceptor was produced in the same manner as in Example 13 except that the fullerene derivative having a hydroxy group was changed to a compound represented by the following structural formula (E-1).

(Comparative Example 2)
An electrophotographic photoreceptor was produced in the same manner as in Example 13 except that the fullerene derivative having a hydroxy group was changed to a compound represented by the following structural formula (E-2).

(Comparative Example 3)
An electrophotographic photoreceptor was produced in the same manner as in Example 17 except that the fullerene derivative having a hydroxy group was changed to the compound represented by the structural formula (E-1).

(Comparative Example 4)
An electrophotographic photoreceptor was produced in the same manner as in Example 17 except that the fullerene derivative having a hydroxy group was changed to the compound represented by the structural formula (E-2) in Example 17.

(Comparative Example 5)
An electrophotographic photoreceptor was produced in the same manner as in Example 17 except that the fullerene derivative having a hydroxy group was changed to a compound represented by the following structural formula (E-3).

(Comparative Example 6)
An electrophotographic photoreceptor was produced in the same manner as in Example 22 except that the fullerene derivative having a hydroxy group was changed to the compound represented by the structural formula (E-3) in Example 22.

(Comparative Example 7)
As shown below, the compound represented by the structural formula (E-3) was allowed to act on the zinc oxide particles that had been surface-treated with the silane coupling agent used in Example 22 to perform organic compound treatment.

  That is, 51.5 parts of zinc oxide particles surface-treated with a silane coupling agent and 1 part of the compound represented by the structural formula (E-3) were mixed in 200 parts of toluene and stirred at room temperature for 3 hours. Thereafter, the solvent was distilled off, and vacuum drying was carried out at 50 ° C. for 3 hours to obtain organic oxide-treated zinc oxide particles.

  In Example 22, the metal oxide particles were mixed with 4.2 parts of the above-described organic compound-treated zinc oxide particles (breakdown: 0.12 part of trimethoxyvinylsilane, 0.08 part of the compound represented by the above structural formula (E-3), The electrophotographic photosensitive member was produced in the same manner as in Example 22 except that the zinc oxide particles were changed to 4 parts) and the fullerene derivative having a hydroxy group was not used.

(Comparative Example 8)
As described below, the compound represented by the following structural formula (E-4) was allowed to act on the zinc oxide particles used in Example 17 to perform organic compound treatment.

  That is, 50 parts of zinc oxide particles (trade name: MZ-500) manufactured by Teika Co., Ltd. and 1 part of a compound represented by the following structural formula (E-4) were mixed in 200 parts of toluene, stirred, and room temperature. For 5 hours. Thereafter, the solvent was distilled off, and vacuum drying was carried out at 80 ° C. for 5 hours to obtain organic oxide-treated zinc oxide particles.

  In Example 17, the metal oxide particles were changed to 4.08 parts of the above-described organic compound-treated zinc oxide particles (breakdown: 0.08 parts of the compound represented by the following structural formula (E-4), 4 parts of zinc oxide particles). Then, an electrophotographic photosensitive member was produced in the same manner as in Example 17 except that the fullerene derivative having a hydroxy group was not used.

(Comparative Example 9)
In Example 13, an electrophotographic photosensitive member was produced in the same manner as in Example 13 except that the fullerene derivative having a hydroxy group was not used.

(Comparative Example 10)
An electrophotographic photosensitive member was produced in the same manner as in Example 17 except that the fullerene derivative having a hydroxy group was not used in Example 17.

  The amount of the metal oxide particles used in Comparative Example 6 described in Table 3 used in the amount of 4.12 parts is the total of trimethoxyvinylsilane and zinc oxide particles, which are metal oxide particles. Part, 4 parts of zinc oxide particles. The amount used of 4.2 parts of the metal oxide particles of Comparative Example 7 shown in Table 3 is trimethoxyvinylsilane, the compound represented by the structural formula (E-3) and zinc oxide particles which are metal oxide particles. The breakdown is 0.12 part of trimethoxyvinylsilane, 0.08 part of the compound represented by the structural formula (E-3), and 4 parts of zinc oxide particles. The usage amount 4.08 parts of the metal oxide particles of Comparative Example 8 described in Table 3 is the total of the compound represented by the structural formula (E-4) and the zinc oxide particles which are metal oxide particles, The breakdown is 0.08 part of the compound represented by the structural formula (E-4) and 4 parts of zinc oxide particles.

(Evaluation)
About the evaluation method of the electrophotographic photosensitive member of Examples 1-23 and Comparative Examples 1-10, it is as follows.

<Potential fluctuation>
As an evaluation device, Canon Co., Ltd. copier (trade name: GP405, process speed is 210 mm / sec, (primary) charging means is a rubber roller type contact charging (charging roller) in which an alternating current is superimposed on a direct current) The exposure means is laser image exposure, the development means is a one-component magnetic negative toner non-contact development system, the transfer means is a roller-type contact transfer system, the cleaning means is a cleaner with a rubber blade set in the counter direction, and the pre-exposure means uses a fuse lamp. Used pre-exposure). In this evaluation apparatus, the electrophotographic photoreceptors of Examples 1 to 23 and Comparative Examples 1 to 10 were installed.

  The evaluation apparatus was installed in an environment of temperature 23 ° C./humidity 5% RH. When the AC component of the charging roller is 1500 Vpp, 1500 Hz and the DC component is −850 V, the initial dark part potential (Vda) before the long-term durability test and the initial bright part potential (Vla) before the long-term durability test in 780 nm laser exposure irradiation are used. ) Was adjusted to −200 V in each electrophotographic photosensitive member.

  The surface potential of the electrophotographic photosensitive member was measured by removing the developing cartridge from the evaluation device and inserting a potential measuring device there. The potential measuring device is configured by arranging a potential measuring probe at the developing position of the developing cartridge, and the position of the potential measuring probe with respect to the electrophotographic photosensitive member is substantially the center in the axial direction of the drum-shaped electrophotographic photosensitive member. The gap from the surface of the electrophotographic photosensitive member was 3 mm.

  Next, the evaluation procedure was performed according to the following (1) and (2). The evaluations (1) and (2) below were carried out with the AC / DC components and exposure conditions set initially in each electrophotographic photoreceptor unchanged. Further, the electrophotographic photosensitive member was evaluated after leaving it to stand for 48 hours in order to adapt it to an environment of temperature 23 ° C./humidity 5% RH.

  (1) An electrophotographic photosensitive member and a potential measuring device are attached to the evaluation device, and a short-term durability test of 999 sheets is performed without passing paper prior to the long-term durability test. Vdb) and the light potential (Vlb) of the 999th sheet before the long-term durability test were measured. And the amount of fluctuation | variation with the initial dark part electric potential (Vda) before the said long-term durability test and the initial bright part electric potential (Vla) before a long-term durability test was confirmed. These were designated as ΔVd (ab) before the long-term durability test and ΔVl (ab) before the long-term durability test, respectively.

Initial dark part potential (Vda) before long-term durability test−999th dark part potential (Vdb) before long-term durability test = ΔVd (ab) before long-term durability test
Initial light portion potential (Vla) before long-term durability test−999th sheet light portion potential (Vlb) before long-term durability test = ΔVl (ab) before long-term durability test

  (2) Thereafter, the potential measuring device was removed, a developing cartridge was attached, and a long-term durability test was conducted by passing 50,000 sheets. After completion of the long-term durability test, the sample was left in the same environment (temperature 23 ° C./humidity 5% RH) for 24 hours. After being left, it was replaced with a potential measuring device, and the short-term durability test of 999 sheets after the long-term durability test was conducted in the same manner as in (1) without passing paper. The initial dark part potential (Vdc) after the long-term endurance test, the initial bright part potential (Vlc) after the long-term endurance test, the 999th dark part potential (Vdd) after the long-term endurance test, and the long-term endurance test The amount of fluctuation from the 999th bright portion potential (Vld) was confirmed. These were set as ΔVd (cd) after the long-term durability test and ΔVl (cd) after the long-term durability test, respectively.

Initial dark portion potential (Vdc) after long-term durability test−999th dark portion potential (Vdd) after long-term durability test = ΔVd (cd) after long-term durability test
Initial light portion potential (Vlc) after long-term durability test−999th light portion potential (Vld) after long-term durability test = ΔVl (cd) after long-term durability test
The sequence during the 50,000-sheet endurance test (long-term endurance test) was an intermittent mode (8 seconds / sheet) that stopped once for each sheet of A4 size paper at a 6% printing ratio.
The evaluation results are shown in Table 4.

DESCRIPTION OF SYMBOLS 1 Electrophotographic photoreceptor 2 Axis 3 Charging means 4 Exposure light 5 Developing means 6 Transfer means 7 Cleaning means 8 Fixing means 9 Process cartridge 10 Guide means P Transfer material

Claims (6)

In an electrophotographic photosensitive member having a support, an intermediate layer provided on the support, and a photosensitive layer provided on the intermediate layer,
The electrophotographic photoreceptor, wherein the intermediate layer contains metal oxide particles, an organic resin, and a fullerene derivative having a hydroxy group.   The electrophotographic photosensitive member according to claim 1, wherein the intermediate layer contains a fullerene derivative having a hydroxy group in an amount of 0.05% by mass to 4.00% by mass with respect to the metal oxide particles.   The electrophotographic photosensitive member according to claim 1, wherein the intermediate layer contains the organic resin in an amount of 10% by mass to 50% by mass with respect to the metal oxide particles.   The electrophotographic photosensitive member according to claim 1, wherein the metal oxide particles are zinc oxide particles.   An electrophotographic photosensitive member according to any one of claims 1 to 4 and at least one means selected from the group consisting of a charging means, a developing means, a transfer means and a cleaning means are integrally supported, and an electrophotographic A process cartridge which is detachable from the apparatus main body.   An electrophotographic apparatus comprising: the electrophotographic photosensitive member according to claim 1; and a charging unit, an exposing unit, a developing unit, and a transferring unit.