JP2009211046A - Image forming apparatus and process cartridge for image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus suppressing contamination of the environment and a charged body with a discharge product generated by a corona charger, and to provide a process cartridge for image forming apparatus. <P>SOLUTION: The image forming apparatus includes: a photoreceptor having a crosslinked surface layer 39; and a corona charger for charging the photoreceptor the charging grid surface of which includes a coat layer containing at least zeolite, a conductive agent and a binder resin. The photoreceptor is preferably a function separating type photoreceptor including a charge blocking layer, a moire prevention layer, a charge generation layer 35, a charge transport layer 37 and a crosslinked surface layer 39, which are provided in this order on a conductive support 31. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The present invention relates to an image forming apparatus used in a copying machine, a laser printer, a facsimile, and the like, and a process cartridge for the image forming apparatus.
Specifically, it has maintained extremely high mechanical durability and stable electrical characteristics in long-term use, and has achieved high reliability that does not cause abnormal images such as image blur due to discharge products generated from the corona charger. The present invention relates to an image forming apparatus and a process cartridge for the image forming apparatus.

  In general, an image forming apparatus irradiates a uniformly charged photoconductor with writing light modulated by image data to form an electrostatic latent image on the photoconductor, and this electrostatic latent image is formed. Toner is supplied to the photoreceptor by a developing unit, and a toner image is formed on the photoreceptor and developed. The image forming apparatus transfers the toner image on the photosensitive member to transfer paper (recording paper or intermediate transfer member) at the transfer portion, and then heats and pressurizes the toner transferred onto the transfer paper at the fixing portion to fix the toner image. An image forming process is performed in which toner remaining on the body surface is collected by a method such as scraping by a cleaning unit.

  Here, a corona charger is generally used as a means for charging the photosensitive member which is a member to be charged. Corona discharge is a sustained discharge caused by local air breakdown that occurs in a non-uniform electric field. In general, the structure is such that a small diameter wire is stretched in a shield case such as aluminum and a part of the shield case is deleted. Corona ions are released from the deleted region. As the voltage applied to the corona wire is increased, a strong local electric field is formed around the wire, causing partial breakdown of air and sustaining the discharge. This is corona discharge.

  The discharge mode of corona discharge greatly depends on the polarity of the applied voltage. In the case of normal corona discharge, a uniform discharge is formed on the corona wire surface. In the case of negative corona discharge, a discharge form in which streamer discharge is scattered is obtained. Positive corona discharge has good charging uniformity, but negative corona discharge causes discharge unevenness. In addition, the amount of ozone generated by discharge is about an order of magnitude greater in the negative corona than in the positive corona, and the load on the environment is also large.

Next, the corona charger and its features will be described by form.
(1) Corotron-type corona charger A configuration of a corotron-type corona charger and a charging method using the same is shown in FIG. The corotron-type corona charger has a structure in which a tungsten wire having a diameter of 50 to 100 μm is shielded with a metal about 1 cm apart. A high voltage of 5 to 10 kV is applied to the corona wire in a state where the opening surface is arranged to face the member to be charged, and positive or negative ions generated thereby are moved to the surface of the member to be charged and charged. As shown in FIG. 2 (a), the corotron type corona charger generates a certain amount of charge, and is not necessarily good at uniformly charging the surface of the object to be charged at a constant potential. It is particularly effective as a transfer charger intended to give a constant charge to the recording paper.

(2) Scorotron-type corona charger The scorotron-type corona charger has been devised in order to reduce the unevenness of the charged potential on the surface of the object to be charged. As shown in FIG. 1B, several wires or meshes are arranged as grid electrodes on the opening surface of the corotron. The opening surface of the scorotron charger is made to face the member to be charged, and a bias voltage is applied to the grid electrode.
FIG. 2B shows charging characteristics of the scorotron type corona charger. A feature of the scorotron type corona charger is that the charging potential is regulated by the voltage applied to the grid electrode even when the charging time is long, and the surface potential is saturated. This saturation value can be controlled by the grid applied voltage. The scorotron-type corona charger has a complicated structure and inferior charging efficiency as compared with the corotron-type, but is excellent in uniformity of charging potential and widely used. The grid electrode in the electrophotographic image forming apparatus is called a charging grid.

In particular, when a corona charger that performs negative corona discharge is used as the above-described charger, it is known that a substance in the air reacts by discharge to generate a substance called a discharge product. It contains ozone (O ₃ ) in which oxygen is oxidized and nitrogen oxides (NOx) such as nitrogen monoxide (NO) and nitrogen dioxide (NO ₂ ) in which nitrogen is oxidized by ozone. Ozone is a substance that feels odor at about 0.1 ppm and adversely affects the respiratory system. Among nitrogen oxides, nitrogen dioxide (NO ₂ ) has an adverse effect on human respiratory organs, but the daily average of hourly values is determined to be 0.04 to 0.06 ppm or less according to environmental standards. In addition, nitrogen oxides are converted into a substance called photochemical oxidant (Ox) by a photochemical reaction by ultraviolet rays, and the environmental standard is also set to 0.06 ppm or less for this substance. The amount of each discharge is several tens of ppm for ozone and several ppm for nitrogen oxides. At present, reducing the amount of discharge outside the image forming apparatus using a filter such as activated carbon reduces the burden on the environment. is doing.

  On the other hand, the discharge products generated from the corona charger may adversely affect the image quality. Specifically, density unevenness may occur immediately under the corona charger after being left for a long time. This occurs at the time of discharge during the image forming operation, and the discharge product adhering to the inner wall of the corona charger gradually contaminates the object to be charged while the device is stopped. A surface potential difference is generated in this portion, and as a result, image density unevenness occurs. This problem occurs more prominently in a low humidity environment of about 20% RH, and gradually recovers when placed in a normal temperature and normal humidity environment. It has been confirmed that the surface of the object to be charged reacts reversibly with the discharge product, and the potential difference is generated because the capacitance increases or the resistance decreases. Although occurrence has been confirmed in any of the photoreceptors, the occurrence is particularly remarkable in a photoreceptor provided with a crosslinked surface layer having high mechanical durability. FIG. 3 is a schematic diagram for explaining density unevenness directly under the corona charger.

  Further, the discharge product may cause a reduction in resolution such as image flow (or image flow, image blur, etc.). This depends on paper dust adhesion and the usage environment, but the main factor is the discharge product. In the current state of using a charging method with discharge, the image flow (or image flow, image blur) Etc.) has occurred. In reality, image flow (or image flow, image blur, etc.) is generated even in the injection charging method in which the amount of discharge products is small. The image flow caused by the above factors causes the photosensitive member to be polished to the minimum necessary to remove the causative substance, and if the polishing cannot be performed, the discharge product is volatilized by heating the photosensitive member to clean the surface of the photosensitive member. Although the state can be recovered, there are problems such as a reduction in the life of the photoreceptor, power and space, and control means. In addition, high durability photoconductors that have been developed in recent years have much less wear on the photoconductor, so that it is more difficult to remove causative substances of image flow (or image flow, image blur, etc.) than before. Compatibility between the mechanical durability and the suppression of the occurrence of abnormal images due to discharge products is a major issue in this field.

  When the cause of the occurrence of image flow (or image flow, image blur, etc.) is estimated, the discharge product first adheres to the photoconductor in the form of spots (stains) and then gradually diffuses. Even if the discharge product adheres, image flow (or image flow, image blur, etc.) does not occur in the initial stage, but if this is not removed, the adhesion area gradually increases and a hygroscopic low-resistance region is formed on the surface of the photoreceptor. Is done. In image flow (or image flow, image blur, etc.), the charge during image formation diffuses on or near the surface of the photoconductor, so that an electrostatic latent image that is faithful to the exposure pattern is not formed, and the edges are blurred and blurred This is an image phenomenon. That is, when an electrostatic latent image is formed, if the photosensitive member has a low resistance region, charge diffusion occurs there and the electrostatic latent image is disturbed. FIG. 4 is a schematic diagram for explaining image flow (or image flow, image blur, etc.).

FIG. 4 shows a state where charges are diffused. On the other hand, as the change in resistance value of the photosensitive member is smaller, the diffusion of charges can be suppressed. The margin is high and the reduction in resolution is small. When the change of the resistance value is large and the volume resistivity is 10 ¹² (Ω · cm) or less, a clear image flow occurs and the resolution is remarkably lowered. At this time, the potential shape does not become a rectangular wave potential shape, but becomes a dull potential shape, the charging potential decreases and the exposure portion potential increases, and the potential shape has a narrow potential contrast. These phenomena tend to worsen with the lapse of time of use of the photoreceptor and with an increase in humidity.

  Further, in an image forming apparatus using a scorotron charger that performs corona discharge, raindrop-like unevenness may occur in the output image. This is due to the presence of large unevenness in the charge amount in a small range in charging of the photosensitive member by the corona charger. This unevenness is caused by, for example, defective discharge due to local adhesion of the toner adhering to the charging wire, silica as its additive, or the discharge product, or a similar substance having high electric resistance adheres to the charging grid and is discharged. The generated charge does not flow through the grid and the amount of movement to the photoconductor increases, or the charged grid itself increases in electrostatic capacity, and the surface potential of the photoconductor rises locally above the voltage applied to the charge grid. It can be considered.

Various studies have been made on corona chargers so far. In Patent Document 1, a charging grid made of a stainless steel corona charger contains graphite particles, nickel particles, aluminum compound particles, and an organic resin binder. The electroconductive coating is applied, the corrosion by the discharge product of the control electrode is suppressed, and the generated discharge product is absorbed by the conductive film, thereby suppressing the contamination of the object to be charged. The fine particles in the film use the action of absorbing the discharge product, but the amount that can be absorbed is determined by the number of adsorption sites of the particles, so the adsorption sites are quickly buried when used over time. The effect is expected to fade. Further, in Patent Document 2, an opening is provided in a corona charger, and ozone diffusion is suppressed by forming an ozone adsorbing particle layer in a finely divided communication opening installed there. Zeolite and activated carbon are used for the ozone adsorption particles. According to this invention, it is possible to suppress the diffusion of ozone to some extent, but the diffusion to the charged body side cannot be sufficiently suppressed, that is, the charged object contamination cannot be sufficiently suppressed. The occurrence of abnormal images such as image blur was inevitable. Further, in Patent Document 3, in addition to the product removing means for adsorbing the discharge product attached to the surface of the member to be charged, the product adhesion preventing means for making it difficult to attach the discharge product to the surface of the member to be charged; At least one of a resistance reduction preventing means for preventing the discharge product adhering to the resistance from decreasing and a product generation preventing means for reducing the amount of discharge product generated in the vicinity of the surface of the member to be charged. Although there is an example in which an adsorbent such as zeolite is disposed between a charged object and a corona charger, another discharge product adsorbing means may be brought into contact with the charged object. It is essential and a plurality of members are required. Further, when the adsorbent is disposed between the charged body and the corona charger, it is expected that charging of the charged body becomes unstable. As described above, at present, high-quality image output that can be satisfied over a long period of time has not been realized.
JP 2005-227470 A Japanese Utility Model Publication No. 62-089660 JP 2003-43894 A

  The present invention has been made in view of the above-described problems of the prior art, and an image forming apparatus and an image forming apparatus process capable of suppressing contamination of an environment and a charged body due to discharge products generated by a corona charger. An object is to provide a cartridge.

  As a result of intensive studies to solve the above-mentioned problems, the present inventor has obtained a discharge product removal function in the charging grid, so that a discharge product generated from the corona charger over a long period of time without requiring a plurality of members. Can prevent air pollution and contamination of the charged body, reduce the environmental load, and at the same time, prevent the photoconductor from deteriorating, and can suppress the occurrence of abnormal images due to the discharge products generated by the corona charger. It has been found that a high-quality image output with very high reliability can be realized over a long period of time by using a highly durable photoconductor together, and the present invention has been achieved. That is, the present invention has been completed by the following constituent requirements.

(1) An image having a photoconductor having a crosslinked surface layer, and the surface of the charging grid of a corona charger for charging the photoconductor having a coat layer containing at least zeolite, a conductive agent and a binder resin. Forming equipment.
(2) The photoreceptor is a function-separated photoreceptor in which a charge blocking layer, a moire preventing layer, a charge generation layer, a charge transport layer, and a crosslinked surface layer are provided in this order on a conductive support. (1) The image forming apparatus according to (1).
(3) The image forming apparatus according to (1) or (2), wherein the conductive agent is indium tin oxide.
(4) The image forming apparatus according to any one of (1) to (3), wherein the binder resin is a phenol resin.
(5) The image forming apparatus according to any one of (1) to (4), wherein the phenol resin is a resol type.
(6) The image forming apparatus according to any one of (1) to (5), wherein the crosslinked surface layer is formed by photocuring.
(7) The image forming apparatus according to (6), wherein the photocuring is performed by ultraviolet rays.
(8) Any one of (1) to (7), wherein the crosslinked surface layer is formed using a coating liquid containing a polymerizable compound having no tri- or higher functional charge transporting structure. The image forming apparatus described in the item.
(9) Any one of (1) to (8), wherein the crosslinked surface layer is formed using a coating liquid containing a polymerizable compound having no pentafunctional or higher functional charge transport structure. The image forming apparatus described in the item.
(10) In any one of (1) to (9), the cross-linked surface layer is formed using a coating liquid containing a polymerizable compound having a mono- or higher functional charge transporting structure. The image forming apparatus described.
(11) In any one of (1) to (10), the cross-linked surface layer is formed using a coating solution containing a polymerizable compound having a bifunctional or higher functional charge transporting structure. The image forming apparatus described.
(12) A process cartridge for use in the image forming apparatus according to any one of (1) to (11), wherein the latent image forms an electrostatic latent image on the surface of the photosensitive member charged by at least a corona charger. An image forming unit, a developing unit that attaches toner to the electrostatic latent image formed by the latent image forming unit, a transfer unit that transfers the toner image formed by the developing unit to a transfer target, and the surface of the photoconductor after transfer A process cartridge for an image forming apparatus, wherein the process cartridge is made by combining one or more cleaning devices for removing toner remaining on the surface of the photosensitive member and the photosensitive member, and is detachable from the main body of the image forming apparatus.

  According to the present invention, conventional problems can be solved, extremely high mechanical durability and stable electrical characteristics can be maintained over a long period of use, and abnormalities such as image blur caused by discharge products generated by a corona charger Provided are an image forming apparatus and a process cartridge for an image forming apparatus that realize high reliability without generating an image.

First, the photoreceptor of the present invention will be described with reference to the drawings. FIG. 5 is a cross-sectional view showing the structure of the photoreceptor of the present invention. A photosensitive layer 33 and a crosslinked surface layer 39 are provided on a conductive support 31. FIG. 6 is a cross-sectional view showing another configuration example of the photoconductor of the present invention. A charge generation layer 35, a charge transport layer 37, and a cross-linked surface layer 39 are provided on a conductive support 31. FIG. 7 is a cross-sectional view showing still another configuration of the present invention, in which an intermediate layer 41, a charge generation layer 35, a charge transport layer 37 and a crosslinked surface layer 39 are provided on a conductive support 31.
FIG. 8 is a cross-sectional view showing another structural example of the photoconductor of the present invention. An intermediate layer 41, a charge generation layer 35, and a cross-linked surface layer 39 are provided on a conductive support 31.

Examples of the conductive support 31 include those having a volume resistance of 10 ¹⁰ Ω · cm or less, for example, metals such as aluminum, nickel, chromium, nichrome, copper, gold, silver, platinum, tin oxide, indium oxide, etc. The metal oxides of the above are coated with film or cylindrical plastic or paper by vapor deposition or sputtering, or a plate of aluminum, aluminum alloy, nickel, stainless steel, etc. and the like by extrusion, drawing, etc. After pipe formation, surface treatment pipes such as cutting, superfinishing, and polishing can be used. Endless nickel belts and endless stainless steel belts can also be used as the conductive support.

  In addition, the conductive support dispersed in a suitable binder resin on the support can be used as the conductive support of the present invention. Examples of the conductive powder include carbon black, acetylene black, metal powder such as aluminum, nickel, iron, nichrome, copper, zinc and silver, or metal oxide powder such as conductive tin oxide and ITO. It is done. The binder resin used at the same time is polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer. , Polyvinyl acetate, polyvinylidene chloride, polyarylate resin, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly-N-vinyl carbazole, acrylic resin, silicone resin, epoxy resin, Examples thereof include thermoplastic, thermosetting resins, and photocurable resins such as melamine resin, urethane resin, phenol resin, and alkyd resin. Such a conductive layer can be provided by dispersing and coating these conductive powder and binder resin in a suitable solvent such as tetrahydrofuran, dichloromethane, methyl ethyl ketone, and toluene.

  Furthermore, it is electrically conductive by a heat shrinkable tube in which the conductive powder is contained in a material such as polyvinyl chloride, polypropylene, polyester, polystyrene, polyvinylidene chloride, polyethylene, chlorinated rubber, Teflon (registered trademark) on a suitable cylindrical substrate. Those provided with a conductive layer can also be used favorably as the conductive support of the present invention.

  Of these, a cylindrical support made of aluminum, which can be easily subjected to the anodic oxide film treatment, can be most preferably used. As used herein, aluminum includes both pure aluminum and aluminum alloys. Specifically, JIS 1000 series, 3000 series, and 6000 series aluminum or aluminum alloy is most suitable. The anodized film is obtained by anodizing various metals and various alloys in an electrolyte solution. Among them, a film called anodized aluminum or an aluminum alloy that has been anodized in an electrolyte solution is used in the present invention. Is the most suitable. In particular, it is excellent in preventing point defects (black spots, background stains) that occur when used in reversal development (negative and positive development).

The anodizing treatment is performed in an acidic bath such as chromic acid, sulfuric acid, oxalic acid, phosphoric acid, boric acid, sulfamic acid. Of these, treatment with a sulfuric acid bath is most suitable. For example, sulfuric acid concentration: 10 to 20%, bath temperature: 5 to 25 ° C., current density: 1 to 4 A / dm ² , electrolytic voltage: 5 to 30 V, treatment time: treatment in the range of about 5 to 60 minutes However, the present invention is not limited to this. Since the anodic oxide film produced in this way is porous and has high insulation, the surface is very unstable. For this reason, there is a change with time after fabrication, and the physical property value of the anodized film is likely to change. In order to avoid this, it is preferable to further seal the anodized film. Examples of the sealing treatment include a method of immersing the anodized film in an aqueous solution containing nickel fluoride and nickel acetate, a method of immersing the anodized film in boiling water, and a method of treating with pressurized steam. Among these, the method of immersing in the aqueous solution containing nickel acetate is the most preferable. Subsequent to the sealing treatment, the anodic oxide film is washed. The main purpose of this is to remove excess metal salts and the like attached by the sealing treatment. If this remains excessively on the surface of the support (anodized film), it not only adversely affects the quality of the coating film formed on this surface, but also generally low resistance components remain, resulting in the occurrence of soiling. It can also be a cause. Cleaning may be performed with pure water only once, but usually, multistage cleaning is performed. At this time, it is preferable that the final cleaning liquid is as clean (deionized) as possible. Moreover, it is preferable to perform physical rubbing cleaning with a contact member in one of the multi-stage cleaning processes. The thickness of the anodized film formed as described above is preferably about 5 to 15 μm. If it is too thin, the barrier effect as an anodic oxide film is not sufficient, and if it is too thick, the time constant as an electrode becomes too large, resulting in the generation of residual potential and the response of the photoreceptor. There is a case.

  In the photoreceptor of the present invention, an intermediate layer can be provided between the conductive support and the photosensitive layer (charge generation layer). The intermediate layer generally contains a resin as a main component, but these resins are preferably resins having a high solvent resistance with respect to a general organic solvent in consideration of applying a photosensitive layer thereon with a solvent. . 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 resin, phenol resin, alkyd-melamine resin, and epoxy. Examples thereof include a curable resin that forms a three-dimensional network structure such as a resin. Further, fine powder pigments of metal oxides exemplified by titanium oxide, silica, alumina, zirconium oxide, tin oxide, indium oxide and the like may be added to the intermediate layer in order to prevent moire and reduce residual potential.

These intermediate layers can be formed by using an appropriate solvent and coating method like the above-mentioned photosensitive layer. Furthermore, a silane coupling agent, a titanium coupling agent, a chromium coupling agent, or the like can be used as the intermediate layer of the present invention. In addition, in the intermediate layer of the present invention, Al ₂ O ₃ is provided by anodic oxidation, organic matter such as polyparaxylylene (parylene), SiO ₂ , SnO ₂ , TiO ₂ , ITO, CeO _2, etc. Those provided with an inorganic material by a vacuum thin film forming method can also be used satisfactorily. In addition, known ones can be used. The thickness of the intermediate layer is suitably from 0 to 5 μm.

  The intermediate layer 41 has at least a function of preventing injection of reverse polarity charges induced on the electrode side to the photosensitive layer when the photosensitive member is charged, and a function of preventing moire generated when writing with coherent light such as laser light. It has two functions. A function separation type intermediate layer in which this function is separated into two or more layers is an effective means for the photoreceptor used in the present invention. The function separation type intermediate layer of the charge blocking layer and the moire preventing layer will be described below.

  The charge blocking layer is a layer having a function of preventing reverse polarity charges induced in the electrode (conductive support 31) during charging of the photoreceptor from being injected into the photosensitive layer from the support. In the case of negative charging, it has a function of preventing hole injection, and in the case of positive charging, it has a function of preventing electron injection. The charge blocking layer includes an anodized film typified by an aluminum oxide layer, an inorganic insulating layer typified by SiO, a layer formed from a glassy network of metal oxide, a layer made of polyphosphazene, an aminosilane reaction A layer made of a product, a layer made of an insulating binder resin, a layer made of a curable binder resin, and the like can be given. Among them, a layer composed of an insulating binder resin or a curable binder resin that can be formed by a wet coating method can be used favorably. Since the charge blocking layer is formed by laminating a moiré preventing layer and a photosensitive layer thereon, when these are provided by a wet coating method, the charge blocking layer must be composed of a material or a structure that does not attack the coating film by these coating solvents. Is essential.

Usable binder resins include thermoplastic resins such as polyamide, polyester, vinyl chloride-vinyl acetate copolymer, and thermosetting resins such as active hydrogen (—OH group, —NH ₂ group, —NH group, etc.). A thermosetting resin obtained by thermally polymerizing a compound containing a plurality of (hydrogen) and a compound containing a plurality of isocyanate groups and / or a compound containing a plurality of epoxy groups can also be used. In this case, examples of the compound containing a plurality of active hydrogens include acrylic resins containing active hydrogen such as polyvinyl butyral, phenoxy resin, phenol resin, polyamide, polyester, polyethylene glycol, polypropylene glycol, polybutylene glycol, and hydroxyethyl methacrylate groups. System resin and the like. Examples of the compound containing a plurality of isocyanate groups include tolylene diisocyanate, hexamethylene diisocyanate, diphenylmethane diisocyanate, and prepolymers thereof. Examples of the compound having a plurality of epoxy groups include bisphenol A type epoxy resin. can give. Among these, polyamide is most preferably used from the viewpoint of film formability, environmental stability, solvent resistance, and the like. Of these, N-methoxymethylated nylon is most preferred. The polyamide resin has a high effect of suppressing charge injection and has little influence on the residual potential. These polyamide resins are alcohol-soluble resins, are insoluble in ketone solvents, can form a uniform thin film even in dip coating, and have excellent coating properties. In particular, this intermediate layer needs to be a thin film in order to minimize the effect of the increase in residual potential, and the uniformity of the film thickness is required. Therefore, the coatability has an important meaning in image quality stability. ing.

  However, in general, alcohol-soluble resins are highly dependent on humidity, which increases resistance in low-humidity environments and increases residual potential.In high-humidity environments, resistance decreases, causing a decrease in charge and increasing environmental dependence. Was a big issue. However, N-methoxymethylated nylon exhibits high insulation properties, is very excellent in blocking the charge injected from the conductive support, has little effect on the residual potential, and is greatly environmentally dependent. Therefore, even when the use environment of the image forming apparatus is changed, it is possible to always maintain a stable image quality. In addition, when N-methoxymethylated nylon is used, the film thickness dependence of the residual potential is small, so that it is possible to reduce the influence on the residual potential and obtain a high scumming suppression effect.

  The substitution rate of the methoxymethyl group in N-methoxymethylated nylon is not particularly limited, but is preferably 15 mol% or more. The above effect by using N-methoxymethylated nylon is affected by the degree of methoxymethylation. When the substitution rate of the methoxymethyl group is lower than this, the humidity dependency increases or the alcohol solution is used. In some cases, the aging stability of the coating solution may be slightly reduced.

In addition, a thermosetting resin obtained by thermally polymerizing an oil-free alkyd resin and an amino resin such as a butylated melamine resin, a polyurethane having an unsaturated bond, a resin having an unsaturated bond such as an unsaturated polyester, and thioxanthone A photocurable resin such as a combination with a photopolymerization initiator such as a methyl compound or methylbenzyl formate can also be used as the binder resin.
In addition, a conductive polymer having a rectifying property or an acceptor (donor) resin / compound may be added in accordance with the charging polarity to provide a function of suppressing charge injection from the substrate.

  The film thickness of the charge blocking layer is 0.1 μm or more and less than 2.0 μm, preferably about 0.3 μm or more and less than 2.0 μm. When the charge blocking layer becomes thick, the residual potential increases remarkably at low temperatures and low humidity due to repeated charging and exposure, and when the film thickness is too thin, the blocking effect is reduced. Add chemicals, solvents, additives, curing accelerators, etc. necessary for curing (crosslinking), and apply to the substrate by conventional methods such as blade coating, dip coating, spray coating, beat coating, nozzle coating, etc. It is formed. After the coating, it is dried or cured by a curing process such as drying, heating, or light.

  The anti-moire layer is a layer having a function of preventing the generation of a moire image due to light interference inside the photosensitive layer when writing with coherent light such as laser light. Basically, it has a function of causing light scattering of the writing light. In order to exhibit such a function, it is effective that the anti-moire layer has a material having a large refractive index. In general, it comprises an inorganic pigment and a binder resin, and the inorganic pigment is dispersed in the binder resin. In particular, white pigments are effectively used among inorganic pigments, and for example, titanium oxide, calcium fluoride, calcium oxide, silicon oxide, magnesium oxide, aluminum oxide, and the like are favorably used. Among these, titanium oxide having a large hiding power can be most effectively used.

  Further, in the photoreceptor having the function separation type intermediate layer, the charge injection from the support 31 is prevented by the charge blocking layer. Therefore, in the moiré preventing layer, at least the charge charged on the photoreceptor surface has the same polarity. From the viewpoint of preventing residual potential, it is preferable to have a function of transferring the electric charge. For this reason, for example, in the case of a negatively charged type photoreceptor, it is desirable to impart electronic conductivity to the moire prevention layer, and the inorganic pigment to be used is one that has electronic conductivity, or one that is conductive. It is desirable. Alternatively, the use of an electron conductive material (for example, an acceptor) or the like for the moire preventing layer makes the effect of the present invention more remarkable.

As the binder resin, the same resin as the charge blocking layer can be used. However, in consideration of laminating the photosensitive layer 33 (charge generating layer 35, charge transporting layer 37) on the moire preventing layer, the photosensitive layer (charge generating layer) is used. It is important not to be affected by the coating solvent of the charge transport layer.
A thermosetting resin is preferably used as the binder resin. In particular, alkyd / melamine resin mixtures are best used. At this time, the mixing ratio of the alkyd / melamine resin is an important factor that determines the structure and characteristics of the moire prevention layer. A range in which the ratio (mass ratio) of both is 5/5 to 8/2 can be cited as a good range of the mixing ratio. If the melamine resin is richer than 5/5, volume shrinkage during thermosetting increases and coating film defects tend to occur, which tends to increase the residual potential of the photoreceptor, which is not desirable. If the alkyd resin is richer than 8/2, it is effective in reducing the residual potential of the photoconductor, but it is not desirable because the bulk resistance becomes too low and the soiling becomes worse.

  In the anti-moire layer, the volume ratio between the inorganic pigment and the binder resin determines an important characteristic. For this reason, it is important that the volume ratio of the inorganic pigment to the binder resin is in the range of 1/1 to 3/1. When the volume ratio of the two is less than 1/1, not only the moire prevention ability is lowered, but there is a case where the increase of the residual potential in repeated use becomes large. On the other hand, in the region where the volume ratio exceeds 3/1, not only the binding ability of the binder resin is inferior, but also the surface property of the coating film is deteriorated, which may adversely affect the film forming property of the upper photosensitive layer. This effect can be a serious problem when the photosensitive layer is a laminated type and a thin layer such as a charge generation layer is formed. When the volume ratio exceeds 3/1, there are cases where the binder resin cannot cover the surface of the inorganic pigment, and the direct contact with the charge generation material increases the probability of heat carrier generation, resulting in soiling. It may have an adverse effect on it.

  Furthermore, by using two types of titanium oxides having different average particle diameters for the moire prevention layer, it is possible to improve the concealing power to the conductive substrate and suppress moire and to cause a pin that causes an abnormal image. The hole can be eliminated. For this purpose, it is important that the ratio of the average particle diameters of the two types of titanium oxide used is within a certain range (0.2 <D2 / D1 ≦ 0.5). In the case of the particle size ratio outside the range specified in the present invention, that is, the ratio of the average particle size (D2) of the other titanium oxide (T2) to the average particle size (D1) of the titanium oxide (T1) having a large average particle size is If it is too small (0.2 ≧ D2 / D1), the activity on the surface of titanium oxide is increased, and the electrostatic stability of the photosensitive member is significantly impaired. Further, when the ratio of the average particle diameter of the other titanium oxide (T2) to the average particle diameter of one titanium oxide (T1) is too large (D2 / D1> 0.5), the hiding power to the conductive substrate is lowered. In addition, the suppression of moiré and abnormal images is reduced. The average particle size mentioned here is obtained from a particle size distribution measurement obtained when strong dispersion is performed in an aqueous system.

Further, the average particle size (D2) of titanium oxide (T2) having a smaller particle size is an important factor, and it is important that 0.05 μm <D2 <0.20 μm. When the thickness is 0.05 μm or less, the hiding power is reduced, and moire may be generated. On the other hand, when the thickness is 0.20 μm or more, the filling rate of the titanium oxide in the moire preventing layer is lowered, and the background dirt suppressing effect cannot be sufficiently exhibited.
The mixing ratio (mass ratio) of the two types of titanium oxide is also an important factor. When T2 / (T1 + T2) is smaller than 0.2, the filling rate of titanium oxide is not so large and the effect of suppressing scumming cannot be exhibited sufficiently. On the other hand, when it is larger than 0.8, the concealing power is reduced, and moire may be generated. Therefore, it is important that 0.2 ≦ T2 / (T1 + T2) ≦ 0.8.
The thickness of the moire preventing layer is 1 to 10 μm, preferably 2 to 5 μm. If the film thickness is less than 1 μm, the effect is small, and if it exceeds 10 μm, residual potential is accumulated, which is not desirable.

  The inorganic pigment is dispersed together with a solvent and a binder resin by a conventional method, for example, a ball mill, a sand mill, an attrier, etc., and if necessary, a chemical, a solvent, an additive, a curing accelerator, etc. necessary for curing (crosslinking) are added. In general, it is formed on the substrate by blade coating, dip coating, spray coating, beat coating, nozzle coating or the like. After the coating, it is dried or cured by a curing process such as drying, heating, or light.

  Next, the photosensitive layer will be described. The photosensitive layer may be a single layer photosensitive layer (FIG. 5) containing a charge generation material and a charge transport material, but a laminated type (FIGS. 6 and 7) composed of a charge generation layer and a charge transport layer is sensitive and durable. It shows excellent properties in performance and is used well. For convenience of explanation, the photosensitive layer having a laminated structure will be described first.

  The charge generation layer is a layer mainly composed of a charge generation material. The charge generation material is not particularly limited, and a known material can be used. Among them, titanyl phthalocyanine having a maximum diffraction peak at 27.2 ° as a diffraction peak (± 0.2 °) with a Bragg angle 2θ with respect to the characteristic X-ray (wavelength 1.542 mm) of CuKα can be used effectively. In particular, as a diffraction peak (± 0.2 °) at a Bragg angle 2θ with respect to the characteristic X-ray (wavelength 1.542 mm) of the crystal type and CuKα described in Japanese Patent Laid-Open No. 2001-19871, the maximum diffraction is at least 27.2 °. It has a peak, and further has main peaks at 9.4 °, 9.6 °, and 24.0 °, and has a peak at 7.3 ° as the lowest diffraction peak, and 7.3 °. A titanyl phthalocyanine crystal having no peak between the peak at 9.4 ° and a peak at 9.4 ° is preferably used, and a crystal having no peak at 26.3 ° can be used effectively. Further, it has the above crystal type, and has an average particle size of 0.25 μm or less at the time of crystal synthesis or by dispersion filtration treatment, and has no coarse particles (Japanese Patent Laid-Open Nos. 2004-83859 and 2004-2004). 78141) is most useful.

The charge generation layer is dispersed by using a ball mill, an attritor, a sand mill, an ultrasonic wave or the like in a suitable solvent together with a binder resin, if necessary, and this is applied onto a conductive support. It is formed by drying.
As the binder resin used for the charge generation layer as necessary, polyamide, polyurethane, epoxy resin, polyketone, polycarbonate, silicone resin, acrylic resin, polyvinyl butyral, polyvinyl formal, polyvinyl ketone, polystyrene, polysulfone, poly-N- Vinyl carbazole, polyacrylamide, polyvinyl benzal, polyester, phenoxy resin, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyphenylene oxide, polyamide, polyvinyl pyridine, cellulosic resin, casein, polyvinyl alcohol, polyvinyl pyrrolidone, etc. It is done. The amount of the binder resin is suitably 0 to 500 parts by mass, preferably 10 to 300 parts by mass with respect to 100 parts by mass of the charge generating material.

  Examples of the solvent used here include isopropanol, acetone, methyl ethyl ketone, cyclohexanone, tetrahydrofuran, dioxane, ethyl cellosolve, ethyl acetate, methyl acetate, dichloromethane, dichloroethane, monochlorobenzene, cyclohexane, toluene, xylene, ligroin and the like. As a coating method for the coating solution, a dip coating method, spray coating, beat coating, nozzle coating, spinner coating, ring coating, or the like can be used. The thickness of the charge generation layer is suitably about 0.01 to 5 μm, preferably 0.1 to 2 μm.

The charge transport layer can be formed by dissolving or dispersing a charge transport material and a binder resin in an appropriate solvent, and applying and drying the solution on the charge generation layer. Moreover, a plasticizer, a leveling agent, antioxidant, etc. can also be added as needed.
Charge transport materials include hole transport materials and electron transport materials. Examples of hole transport materials include poly-N-vinylcarbazole and derivatives thereof, poly-γ-carbazolylethyl glutamate and derivatives thereof, pyrene-formaldehyde condensates and derivatives thereof, polyvinylpyrene, polyvinylphenanthrene, polysilane, oxazole derivatives, Oxadiazole derivatives, imidazole derivatives, monoarylamine derivatives, diarylamine derivatives, triarylamine derivatives, stilbene derivatives, α-phenylstilbene derivatives, benzidine derivatives, diarylmethane derivatives, triarylmethane derivatives, 9-styrylanthracene derivatives, pyrazolines Derivatives, divinylbenzene derivatives, hydrazone derivatives, indene derivatives, butadiene derivatives, pyrene derivatives, etc., bisstilbene derivatives, enamine derivatives, etc. Other known materials may be mentioned. These charge transport materials may be used alone or in combination of two or more.

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

Binder resins include polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, poly Vinylidene chloride, polyarate, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly-N-vinylcarbazole, acrylic resin, silicone resin, epoxy resin, melamine resin, urethane resin, phenol resin And thermoplastic or thermosetting resins such as alkyd resins.
The amount of the charge transport material is appropriately 20 to 300 parts by mass, preferably 40 to 150 parts by mass with respect to 100 parts by mass of the binder resin. The thickness of the charge transport layer is preferably about 5 to 100 μm.

  Examples of the solvent used here include tetrahydrofuran, dioxane, toluene, dichloromethane, monochlorobenzene, dichloroethane, cyclohexanone, methyl ethyl ketone, and acetone. Among them, the use of a non-halogen solvent is desirable for the purpose of reducing the environmental load. Specifically, cyclic ethers such as tetrahydrofuran, dioxolane and dioxane, aromatic hydrocarbons such as toluene and xylene, and derivatives thereof are preferably used.

  In addition, a polymer charge transport material having a function as a charge transport material and a function of a binder resin is also preferably used for the charge transport layer. The charge transport layer composed of these polymer charge transport materials is excellent in wear resistance. As the polymer charge transport material, known materials can be used, and in particular, a polycarbonate containing a triarylamine structure in the main chain and / or side chain is preferably used. Among these, polymer charge transport materials represented by the formulas (I) to (X) are preferably used, and these are exemplified below and specific examples are shown.

(I) In the formula, R ₁ , R ₂ and R ₃ are each independently a substituted or unsubstituted alkyl group or a halogen atom, R ₄ is a hydrogen atom or a substituted or unsubstituted alkyl group, R ₅ and R ₆ are A substituted or unsubstituted aryl group, o, p, q are each independently an integer of 0-4, k, j represents a composition, 0.1 ≦ k ≦ 1, 0 ≦ j ≦ 0.9, n is It represents the number of repeating units and is an integer of 5 to 5000. X represents an aliphatic divalent group, a cycloaliphatic divalent group, or a divalent group represented by the following general formula. In the formula (I), two copolymer species are described in the form of an alternating copolymer, but a random copolymer may be used.

R ₁₀₁ and R ₁₀₂ each independently represents a substituted or unsubstituted alkyl group, aryl group or halogen atom. l and m are integers of 0 to 4, Y is a single bond, a linear, branched or cyclic alkylene group having 1 to 12 carbon atoms, —O—, —S—, —SO—, —SO ₂ —. , -CO-, -CO-O-Z-O-CO- (wherein Z represents an aliphatic divalent group) or
(A represents an integer of 1 to 20, b represents an integer of 1 to 2000, and R ₁₀₃ and R ₁₀₄ represent a substituted or unsubstituted alkyl group or aryl group). Here, R ₁₀₁ and R ₁₀₂ , and R ₁₀₃ and R ₁₀₄ may be the same or different. )

(II) In the formula, R ₇ and R ₈ represent a substituted or unsubstituted aryl group, and Ar ₁ , Ar ₂ , and Ar ₃ represent the same or different arylene groups. X, k, j and n are the same as in the case of formula (I). In the formula (II), two copolymer species are described in the form of an alternating copolymer, but a random copolymer may be used.

(III) In the formula, R ₉ and R ₁₀ represent a substituted or unsubstituted aryl group, and Ar ₄ , Ar ₅ and Ar ₆ represent the same or different arylene groups. X, k, j and n are the same as in the case of formula (I). In the formula (III), two copolymer species are described in the form of an alternating copolymer, but a random copolymer may be used.

(IV) In the formula, R ₁₁ and R ₁₂ are substituted or unsubstituted aryl groups, Ar ₇ , Ar ₈ and Ar ₉ are the same or different arylene groups, and p is an integer of 1 to 5. X, k, j and n are the same as in the case of formula (I). In the formula (IV), two copolymer species are described in the form of an alternating copolymer, but a random copolymer may be used.

(V) In the formula, R ₁₃ and R ₁₄ are substituted or unsubstituted aryl groups, Ar ₁₀ , Ar ₁₁ and Ar ₁₂ are the same or different arylene groups, X ₁ and X ₂ are substituted or unsubstituted ethylene groups, or A substituted or unsubstituted vinylene group is represented. X, k, j and n are the same as in the case of formula (I). In the formula (V), two copolymer species are described in the form of an alternating copolymer, but a random copolymer may be used.

(VI) _{wherein, R 15, R 16, R} 17, R 18 is a substituted or unsubstituted aryl _{group, Ar 13, Ar 14, Ar} 15, Ar 16 are identical or different arylene group, Y _1, Y _2, Y ₃ represents a single bond, a substituted or unsubstituted alkylene group, a substituted or unsubstituted cycloalkylene group, a substituted or unsubstituted alkylene ether group, an oxygen atom, a sulfur atom, or a vinylene group, which may be the same or different. Good. X, k, j and n are the same as in the case of formula (I). In the formula (VI), two copolymer species are described in the form of an alternating copolymer, but a random copolymer may be used.

In the formula (VII), R ₁₉ and R ₂₀ represent a hydrogen atom or a substituted or unsubstituted aryl group, and R ₁₉ and R ₂₀ may form a ring. Ar ₁₇ , Ar ₁₈ , Ar ₁₉ represent the same or different arylene groups. X, k, j and n are the same as in the case of formula (I). In the formula (VII), two copolymer species are described in the form of an alternating copolymer, but a random copolymer may be used.

(VIII) In the formula, R ₂₁ represents a substituted or unsubstituted aryl group, and Ar ₂₀ , Ar ₂₁ , Ar ₂₂ , and Ar ₂₃ represent the same or different arylene groups. X, k, j and n are the same as in the case of formula (I). In the formula (VIII), two copolymer species are described in the form of an alternating copolymer, but a random copolymer may be used.

In the formula (IX), R ₂₂ , R ₂₃ , R ₂₄ and R ₂₅ represent a substituted or unsubstituted aryl group, and Ar ₂₄ , Ar ₂₅ , Ar ₂₆ , Ar ₂₇ and Ar ₂₈ represent the same or different arylene groups. X, k, j and n are the same as in the case of formula (I). In the formula (IX), two copolymer species are described in the form of an alternating copolymer, but a random copolymer may be used.

In the formula (X), R ₂₆ and R ₂₇ represent a substituted or unsubstituted aryl group, and Ar ₂₉ , Ar ₃₀ and Ar ₃₁ represent the same or different arylene groups. X, k, j and n are the same as in the case of formula (I). In the formula (X), two copolymer species are described in the form of an alternating copolymer, but a random copolymer may be used.

Further, as the polymer charge transport material used in the charge transport layer, in addition to the polymer charge transport material described above, in the state of the monomer or oligomer having an electron donating group at the time of film formation of the charge transport layer, A polymer having a two-dimensional or three-dimensional crosslinked structure is finally included by carrying out a curing reaction or a crosslinking reaction.
Further, a charge transport layer having a crosslinked structure is also effectively used as the structure of the charge transport layer. Regarding the formation of a cross-linked structure, a reactive monomer having a plurality of cross-linkable functional groups in one molecule is used to cause a cross-linking reaction using light or thermal energy to form a three-dimensional network structure. is there. This network structure functions as a binder resin and exhibits high wear resistance.

Moreover, it is a very effective means to use a monomer having a charge transporting ability in whole or in part as the reactive monomer. By using such a monomer, a charge transport site is formed in the network structure, and the function as the charge transport layer can be sufficiently expressed. A reactive monomer having a triarylamine structure is effectively used as the monomer having charge transporting ability.
The charge transport layer having such a network structure has high wear resistance, but has a large volume shrinkage during the crosslinking reaction, and if it is too thick, cracks may occur. In such a case, the charge transport layer has a laminated structure, the lower layer (charge generation layer side) uses a low molecular dispersion polymer charge transport layer, and the upper layer (surface side) has a cross-linked structure. It may be formed.

A charge transport layer composed of a polymer having these electron donating groups or a polymer having a crosslinked structure is excellent in wear resistance. Usually, in the electrophotographic process, since the charging potential (unexposed portion potential) is constant, if the surface layer of the photoreceptor is worn by repeated use, the electric field strength applied to the photoreceptor increases accordingly. As the electric field strength increases, the occurrence frequency of scumming increases. Therefore, the high wear resistance of the photosensitive member is advantageous for scumming. The charge transport layer composed of a polymer having these electron donating groups is a polymer compound, so it has excellent film-forming properties and has a charge transport site compared to a charge transport layer composed of a low molecular weight dispersed polymer. It can be configured with high density and has excellent charge transport capability. For this reason, a photoreceptor having a charge transport layer using a polymer charge transport material can be expected to have a high response speed.
Examples of the other polymer having an electron donating group include a copolymer of a known monomer, a block polymer, a graft polymer, a star polymer, and, for example, JP-A-3-109406, JP-A-2000- It is also possible to use a crosslinked polymer having an electron donating group as disclosed in JP-A-206723 and JP-A No. 2001-34001.

  In the present invention, a plasticizer or a leveling agent may be added to the charge transport layer. As the plasticizer, those used as plasticizers for general resins such as dibutyl phthalate and dioctyl phthalate can be used as they are, and the amount used is suitably about 0 to 30% by mass with respect to the binder resin. 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 0 with respect to the binder resin. 1% by weight is appropriate.

  In the above description, the photosensitive layer has a laminated structure. However, in the present invention, the photosensitive layer may have a single layer structure. In order to make the photosensitive layer as a single layer, the photosensitive layer is constituted by providing a single layer containing at least the above-described charge generating substance and a binder resin. As the binder resin, the description of the charge generating layer and the charge transport layer is used. Those described in the above are used well. In addition, when a charge transport material is used in combination with the single-layer photosensitive layer, high photosensitivity, high carrier transport properties, and low residual potential are exhibited, and the single layer photosensitive layer can be used favorably. At this time, as the charge transport material to be used, either a hole transport material or an electron transport material is selected according to the polarity charged on the surface of the photoreceptor. Furthermore, since the above-described polymer charge transporting material also has the functions of a binder resin and a charge transporting material, it is favorably used for a single-layer photosensitive layer.

The crosslinked surface layer that can be used in the present invention is formed by polymerizing at least a polymerizable compound. From the viewpoint of mechanical durability, a polymerizable compound having three or more polymerizable functional groups in the molecule is preferably used. In other words, by polymerizing a polymerizable compound having three or more functional groups, a three-dimensional network structure is developed, a surface layer having a very high crosslink density and a high hardness and high elasticity is obtained, and is uniform and high in smoothness. Abrasion and scratch resistance are achieved. In particular, it is preferable to polymerize a polymerizable compound having five or more functional groups, which can further improve wear resistance and scratch resistance.
Thus, it is important to increase the crosslink density on the surface of the photoreceptor, that is, the number of crosslink bonds per unit volume. However, since a large number of bonds are instantaneously formed in the polymerization reaction, internal stress due to volume shrinkage occurs. Since this internal stress increases as the film thickness of the crosslinkable protective layer increases, if the entire cross-linked surface layer is cured, cracks and film peeling tend to occur. Even if this phenomenon does not appear initially, it may be likely to occur over time due to repeated use in the electrophotographic process and the influence of charging, development, transfer, cleaning hazards and thermal fluctuations.

  As a method for solving this problem, (1) a polymer component is introduced into the crosslinked layer and the crosslinked structure, (2) a large amount of monofunctional and bifunctional radically polymerizable monomers are used, and (3) a flexible group is introduced. Although the directionality which makes a cured resin layer soft, such as using the polyfunctional monomer which has, is mentioned, the crosslink density of a bridge | crosslinking layer becomes thin in any case, and remarkable wear resistance is not achieved. On the other hand, the photoreceptor of the present invention is preferably provided with a crosslinked surface layer having a high crosslinking density with a three-dimensional network structure developed on the photosensitive layer, preferably with a film thickness of 1 μm or more and 15 μm or less. No film peeling occurs and very high wear resistance is achieved. By making the film thickness of the cross-linked surface layer 2 μm or more and 10 μm or less, in addition to improving the margin for the above problem, it is possible to select a material with a high cross-linking density that leads to further improvement in wear resistance. It becomes.

  The reason why the photoconductor of the present invention can suppress cracking and film peeling is that the internal stress does not increase because the cross-linked surface layer can be made thin, and the internal stress of the cross-linked surface layer because the photosensitive layer or charge transport layer is provided in the lower layer. It depends on things that can be mitigated. For this reason, it is not necessary to contain a large amount of the polymer material in the cross-linked surface layer, and scratches and toner filming caused by the incompatibility caused by the reaction between the polymer material and the polymerizable composition that occur at this time are unlikely to occur. . Furthermore, in general, when polymerizing a thick film over the entire cross-linked surface layer by energy irradiation, energy transmission to the inside of the film is limited due to energy absorption of the antioxidant, and the polymerization reaction may not proceed sufficiently. In some cases, the antioxidant may trap the radicals generated by the polymerization reaction, or the polymerization may be suppressed such that the polymerization initiation reaction is suppressed. By injecting the agent, there is no polymerization inhibition or deterioration of the antioxidant due to energy irradiation, the curing reaction progresses uniformly to the inside, high wear resistance is maintained inside as well as the surface, and stable electrical characteristics Can be maintained for a long period of time. In addition, in the formation of the crosslinked surface layer of the present invention, in addition to the polymerizable compound, a charge transporting compound (with or without a polymerizable functional group does not matter, but has a polymerizable functional group from the viewpoint of mechanical durability). It is also possible to contain them. The charge transporting compound having a polymerizable functional group preferably has a smaller number of functional groups from the viewpoint of distortion of the cured resin structure and internal stress of the crosslinked surface layer. From the viewpoint of electrical characteristics, a monofunctional charge transporting compound is preferable. Although it can be used satisfactorily, a larger number of functional groups is preferable from the viewpoint of wear resistance, and a bifunctional or higher functional charge transporting compound can also be used favorably.

Next, the constituent material of the crosslinked surface layer coating solution of the present invention will be described.
Among the polymerizable compounds used in the present invention, examples of the polymerizable compound having no charge transport structure include hole transport structures such as triarylamine, hydrazone, pyrazoline, and carbazole, such as condensed polycyclic quinone, diphenoquinone, It refers to a monomer that does not have an electron transport structure such as an electron-withdrawing aromatic ring having a cyano group or a nitro group, and has a polymerizable functional group. The polymerizable functional group may be any group as long as it has a carbon-carbon double bond and can be polymerized. Examples of these polymerizable functional groups include 1-substituted ethylene functional groups and 1,1-substituted ethylene functional groups shown below.

(1) Examples of the 1-substituted ethylene functional group include functional groups represented by the following formulas.
CH ₂ = CH-X ₁ -... Formula 10
(However, in Formula 10, X ₁ represents an arylene group such as an optionally substituted phenylene group or naphthylene group, an optionally substituted alkenylene group, —CO— group, —COO— Group, —CON (R ₁₀ ) — group (R ₁₀ is an alkyl group such as hydrogen, methyl group or ethyl group, an aralkyl group such as benzyl group, naphthylmethyl group or phenethyl group, or an aryl group such as phenyl group or naphthyl group. Represents a -S- group.)
Specific examples of these functional groups include vinyl group, styryl group, 2-methyl-1,3-butadienyl group, vinylcarbonyl group, acryloyloxy group, acryloylamide group, vinylthioether group and the like.

(2) Examples of the 1,1-substituted ethylene functional group include functional groups represented by the following formulas.
CH ₂ = C (Y) -X ₂ -... Formula 11
(However, in Formula 11, Y is an alkyl group which may have a substituent, an aralkyl group which may have a substituent, a phenyl group which may have a substituent, a naphthyl group, etc. An aryl group, a halogen atom, a cyano group, an nitro group, an alkoxy group such as a methoxy group or an ethoxy group, a -COOR ₁₁ group (R ₁₁ is a hydrogen atom, an optionally substituted methyl group, an ethyl group, etc. An alkyl group, an optionally substituted benzyl, an aralkyl group such as a phenethyl group, an optionally substituted phenyl group, an aryl group such as a naphthyl group, or -CONR ₁₂ R ₁₃ (R ₁₂ and R ₁₃ represents a hydrogen atom, an optionally substituted alkyl group such as a methyl group or an ethyl group, an optionally substituted benzyl group, a naphthylmethyl group, or an aralkyl group such as a phenethyl group; Ma Is a phenyl group which may have a substituent, an aryl group such as phenyl or naphthyl, which may be the same or different from each other.) Further, X ₂ is and the same substituents as X ₁ in the formula 10 Represents a single bond or an alkylene group, provided that at least one of Y and X ₂ is an oxycarbonyl group, a cyano group, an alkenylene group, and an aromatic ring.)
Specific examples of these functional groups include an α-acryloyloxy chloride group, a methacryloyloxy group, an α-cyanoethylene group, an α-cyanoacryloyloxy group, an α-cyanophenylene group, and a methacryloylamino group.

In addition, examples of the substituent further substituted with the substituent for X ₁ , X ₂ , and Y include alkyl groups such as halogen atom, nitro group, cyano group, methyl group, and ethyl group, methoxy group, and ethoxy group. And an aryloxy group such as a phenoxy group, an aryl group such as a phenyl group and a naphthyl group, and an aralkyl group such as a benzyl group and a phenethyl group.

  Among these polymerizable functional groups, an acryloyloxy group and a methacryloyloxy group are particularly useful. For example, a compound having an acryloyloxy group includes a compound having a hydroxyl group in the molecule, acrylic acid (salt), and acrylic acid halide. It can be obtained by esterification or transesterification using an acrylic ester. A compound having a methacryloyloxy group can be obtained in the same manner. Moreover, the polymerizable functional groups in the monomer having two or more polymerizable functional groups may be the same or different.

Examples of the polymerizable compound having no charge transporting structure include the following compounds, but are not limited to these compounds.
For example, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, tetrahydrofurfuryl acrylate, 2-ethylhexyl carbitol acrylate, 3-methoxybutyl acrylate, benzyl acrylate, cyclohexyl acrylate, isoamyl acrylate, isobutyl acrylate, methoxy Triethylene glycol acrylate, phenoxytetraethylene glycol acrylate, cetyl acrylate, isostearyl acrylate, stearyl acrylate, styrene monomer, 1,3-butanediol diacrylate, 1,4-butanediol diacrylate, 1,4-butanediol dimethacrylate 1,6-hexanediol diacrylate, 1,6- Xanthdiol dimethacrylate, diethylene glycol diacrylate, neopentyl glycol diacrylate, bisphenol A-EO modified diacrylate, bisphenol F-EO modified diacrylate, neopentyl glycol diacrylate, trimethylolpropane triacrylate (TMPTA), trimethylolpropane tri Methacrylate, trimethylolpropane alkylene-modified triacrylate, trimethylolpropane ethyleneoxy-modified (hereinafter EO-modified) triacrylate, trimethylolpropane propyleneoxy-modified (hereinafter PO-modified) triacrylate, trimethylolpropane caprolactone-modified triacrylate, trimethylolpropane alkylene Modified trimethacrylate, pentaerythritol Acrylate, pentaerythritol tetraacrylate (PETTA), glycerol triacrylate, glycerol epichlorohydrin modified (hereinafter referred to as ECH modified) triacrylate, glycerol EO modified triacrylate, glycerol PO modified triacrylate, tris (acryloxyethyl) isocyanurate, di Pentaerythritol hexaacrylate (DPHA), dipentaerythritol caprolactone-modified hexaacrylate (DPCA), dipentaerythritol hydroxypentaacrylate, alkylated dipentaerythritol pentaacrylate, alkylated dipentaerythritol tetraacrylate, alkylated dipentaerythritol triacrylate, Dimethylolpropane tetraacrylate (DT MPTA), pentaerythritol ethoxytetraacrylate, phosphoric acid EO-modified triacrylate, 2,2,5,5, -tetrahydroxymethylcyclopentanone tetraacrylate, and the like. These may be used alone or in combination of two or more. There is no problem.

  Among the polymerizable compounds used in the present invention, the polymerizable compound having no charge transporting structure is based on the number of functional groups in the polymerizable compound in order to form a dense crosslinked bond in the crosslinked surface layer. The molecular weight ratio (molecular weight / number of functional groups) is preferably 250 or less. If this ratio is greater than 250, the cross-linked cross-linked surface layer tends to be soft and wear resistance tends to be somewhat lowered, and therefore has a modifying group such as EO, PO, caprolactone, etc. in the compounds exemplified above. It is not preferable to use a compound having an extremely long modifying group alone. Moreover, the component ratio of the polymeric compound which does not have the charge transportable structure used for a crosslinked surface layer is 20 mass% or more with respect to a crosslinked surface layer whole quantity, Preferably it is 30 mass% or more. If the polymerizable compound component is less than 20% by mass, the three-dimensional cross-linking density of the cross-linked surface layer is small, and there is a tendency that a drastic improvement in wear resistance cannot be expected as compared with the case of using a conventional thermoplastic binder resin. On the other hand, if it exceeds 80% by mass, the content of the charge transporting compound tends to decrease, and the electrical characteristics tend to deteriorate. The electrical characteristics and abrasion resistance required vary depending on the process used, and the thickness of the crosslinked surface layer of the photoconductor also varies accordingly. Is most preferred.

  As the charge transporting compound used in the cross-linked surface layer of the present invention, both those having no polymerizable functional group and those having a polymerizable functional group can be used favorably. In terms of electrical characteristics, it is preferred that no charge transporting compound is contained when irradiated with light energy. However, for the purpose of further enhancement of the mechanical durability and the like, the charge transporting compound having a polymerizable functional group is preferred. May be photocured simultaneously. As the charge transporting compound having no polymerizable functional group, the charge transporting material described in the charge transporting layer is preferably used. Further, those having a polymerizable functional group (Japanese Patent Laid-Open No. 2005-107401, Japanese Patent Laid-Open No. 2006-011014, Japanese Patent Laid-Open No. 2006-154969) are preferably used. For example, triarylamine, hydrazone, It has a hole transporting structure such as pyrazoline and carbazole, for example, an electron transporting structure such as condensed polycyclic quinone, diphenoquinone, an electron-withdrawing aromatic ring having a cyano group or a nitro group, and has a polymerizable functional group Refers to a compound. Examples of the polymerizable functional group include those described above for the polymerizable compound having no charge transporting structure, and acryloyloxy group and methacryloyloxy group are particularly useful. In addition, a triarylamine structure has a high effect as a charge transporting structure, and in particular, when a compound represented by the structure of the following general formula (1) or (2) is used, electrical characteristics such as sensitivity and residual potential Is well maintained.

{In General Formulas (1) and (2), R ₁ may have a hydrogen atom, a halogen atom, an alkyl group which may have a substituent, an aralkyl group which may have a substituent, or a substituent. Good aryl group, cyano group, nitro group, alkoxy group, —COOR ₇ (R ₇ has a hydrogen atom, an alkyl group which may have a substituent, an aralkyl group which may have a substituent, or a substituent. Aryl group), a carbonyl halide group or CONR ₈ R ₉ (R ₈ and R ₉ are a hydrogen atom, a halogen atom, an alkyl group which may have a substituent, an aralkyl group which may have a substituent) Or an aryl group which may have a substituent, which may be the same or different from each other), Ar ₁ and Ar ₂ each represent a substituted or unsubstituted arylene group, May be different. Ar ₃ and Ar ₄ represent a substituted or unsubstituted aryl group, and may be the same or different. X represents a single bond, a substituted or unsubstituted alkylene group, a substituted or unsubstituted cycloalkylene group, a substituted or unsubstituted alkylene ether group, an oxygen atom, a sulfur atom, or a vinylene group. Z represents a substituted or unsubstituted alkylene group, a substituted or unsubstituted alkylene ether divalent group, or an alkyleneoxycarbonyl divalent group. m and n represent an integer of 0 to 3. }

Specific examples of general formulas (1) and (2) are shown below.
In the general formulas (1) and (2), in the substituent of R ₁ , examples of the alkyl group include a methyl group, an ethyl group, a propyl group, and a butyl group, and examples of the aryl group include a phenyl group and a naphthyl group. The aralkyl group includes a benzyl group, a phenethyl group, and a naphthylmethyl group, and the alkoxy group includes a methoxy group, an ethoxy group, a propoxy group, and the like. These include a halogen atom, a nitro group, a cyano group, and a methyl group. Substituted with an alkyl group such as an ethyl group, an alkoxy group such as a methoxy group or an ethoxy group, an aryloxy group such as a phenoxy group, an aryl group such as a phenyl group or a naphthyl group, an aralkyl group such as a benzyl group or a phenethyl group, etc. May be.
Among the substituents for R ₁ , particularly preferred are a hydrogen atom and a methyl group.

Ar ₃ and Ar ₄ represent a substituted or unsubstituted aryl group. In the present invention, the aryl group includes a condensed polycyclic hydrocarbon group, a non-condensed cyclic hydrocarbon group, and a heterocyclic group.
The condensed polycyclic hydrocarbon group preferably has 18 or less carbon atoms forming a ring, for example, a pentanyl group, an indenyl group, a naphthyl group, an azulenyl group, a heptaenyl group, a biphenylenyl group, an as-indacenyl group. , S-indacenyl group, fluorenyl group, acenaphthylenyl group, preadenyl group, acenaphthenyl group, phenalenyl group, phenanthryl group, anthryl group, fluoranthenyl group, acephenanthrenyl group, aceanthrylenyl group, triphenylyl group, pyrenyl group , A chrycenyl group, a naphthacenyl group, and the like.
Examples of the non-fused cyclic hydrocarbon group include monovalent groups of monocyclic hydrocarbon compounds such as benzene, diphenyl ether, polyethylene diphenyl ether, diphenyl thioether and diphenyl sulfone, or biphenyl, polyphenyl, diphenylalkane, diphenylalkene, diphenylalkyne, Monovalent groups of non-condensed polycyclic hydrocarbon compounds such as triphenylmethane, distyrylbenzene, 1,1-diphenylcycloalkane, polyphenylalkane, and polyphenylalkene, or ring assemblies such as 9,9-diphenylfluorene And monovalent groups of hydrocarbon compounds.
Examples of the heterocyclic group include monovalent groups such as carbazole, dibenzofuran, dibenzothiophene, oxadiazole, and thiadiazole.

The aryl group represented by Ar ₃ or Ar ₄ may have a substituent as shown below, for example.
(1) Halogen atom, cyano group, nitro group and the like.
(2) Alkyl groups, preferably C ₁ -C _12, especially C ₁ -C ₈ , more preferably C ₁ -C ₄ linear or branched alkyl groups, and these alkyl groups further contain fluorine atoms , a hydroxyl group, a cyano group, an alkoxy group of C ₁ -C _4, a phenyl group or a halogen atom, which may have a phenyl group substituted by an alkoxy group C ₁ -C ₄ alkyl or C ₁ -C ₄ Good. Specifically, methyl group, ethyl group, n-butyl group, i-propyl group, t-butyl group, s-butyl group, n-propyl group, trifluoromethyl group, 2-hydroxyethyl group, 2-ethoxyethyl Group, 2-cyanoethyl group, 2-methoxyethyl group, benzyl group, 4-chlorobenzyl group, 4-methylbenzyl group, 4-phenylbenzyl group and the like.

(3) An alkoxy group (—OR ₂ ), and R ₂ represents the alkyl group defined in (2). Specifically, methoxy group, ethoxy group, n-propoxy group, i-propoxy group, t-butoxy group, n-butoxy group, s-butoxy group, i-butoxy group, 2-hydroxyethoxy group, benzyloxy group And a trifluoromethoxy group.
(4) An aryloxy group, and examples of the aryl group include a phenyl group and a naphthyl group. It may contain an alkoxy group having C ₁ -C _4, alkyl group, or a halogen atom C ₁ -C ₄ as a substituent. Specific examples include a phenoxy group, a 1-naphthyloxy group, a 2-naphthyloxy group, a 4-methoxyphenoxy group, and a 4-methylphenoxy group.
(5) Alkyl mercapto group or aryl mercapto group, and specific examples include methylthio group, ethylthio group, phenylthio group, p-methylphenylthio group and the like.

(6)
(In the formula, R ₃ and R ₄ each independently represents a hydrogen atom, an alkyl group defined in (2) above, or an aryl group. Examples of the aryl group include a phenyl group, a biphenyl group, and a naphthyl group. these C ₁ -C ₄ alkoxy groups, C ₁ -C good .R ₃ and R ₄ may contain as alkyl group or a halogen atom substituents ₄ may be linked to form a ring.)
Specifically, amino group, diethylamino group, N-methyl-N-phenylamino group, N, N-diphenylamino group, N, N-di (tolyl) amino group, dibenzylamino group, piperidino group, morpholino group And pyrrolidino group.

(7) An alkylenedioxy group or an alkylenedithio group such as a methylenedioxy group or a methylenedithio group.
(8) A substituted or unsubstituted styryl group, a substituted or unsubstituted β-phenylstyryl group, a diphenylaminophenyl group, a ditolylaminophenyl group, and the like.

The arylene group represented by Ar ₁ or Ar ₂ is a divalent group derived from the aryl group represented by Ar ₃ or Ar ₄ .
X represents a single bond, a substituted or unsubstituted alkylene group, a substituted or unsubstituted cycloalkylene group, a substituted or unsubstituted alkylene ether group, an oxygen atom, a sulfur atom, or a vinylene group.
The substituted or unsubstituted alkylene group is a C _{1 to} C ₁₂ , preferably C _{1 to} C ₈ , more preferably a C _{1 to} C ₄ linear or branched alkylene group, and these alkylene groups include a fluorine atom, a hydroxyl group, a cyano group, an alkoxy group of C ₁ -C _4, a phenyl group or a halogen atom, a phenyl group substituted with an alkyl group or a C ₁ -C ₄ alkoxy group C ₁ -C ₄ It may be. Specifically, methylene group, ethylene group, n-butylene group, i-propylene group, t-butylene group, s-butylene group, n-propylene group, trifluoromethylene group, 2-hydroxyethylene group, 2-ethoxyethylene. Group, 2-cyanoethylene group, 2-methoxyethylene group, benzylidene group, phenylethylene group, 4-chlorophenylethylene group, 4-methylphenylethylene group, 4-biphenylethylene group and the like.

The substituted or unsubstituted cycloalkylene group is a C _{5 to} C ₇ cyclic alkylene group, and these cyclic alkylene groups include a fluorine atom, a hydroxyl group, a C _{1 to} C ₄ alkyl group, and a C _{1 to} C ₄ alkyl group. It may have an alkoxy group. Specific examples include a cyclohexylidene group, a cyclohexylene group, and a 3,3-dimethylcyclohexylidene group.
The substituted or unsubstituted alkylene ether group represents ethyleneoxy, propyleneoxy, ethylene glycol, propylene glycol, diethylene glycol, tetraethylene glycol, tripropylene glycol, alkylene ether group alkylene group is hydroxyl group, methyl group, ethyl group, etc. You may have the substituent of.

The vinylene group is
R ₅ is hydrogen, an alkyl group (same as the alkyl group defined in (2) above), an aryl group (same as the aryl group represented by Ar ₃ or Ar ₄ above), a is 1 or 2 , B represents 1-3.

Z represents a substituted or unsubstituted alkylene group, a substituted or unsubstituted alkylene ether divalent group, or an alkyleneoxycarbonyl divalent group.
Examples of the substituted or unsubstituted alkylene group include the same alkylene groups as those described above for X.
Examples of the substituted or unsubstituted alkylene ether divalent group include the alkylene ether divalent group of X.
Examples of the alkyleneoxycarbonyl divalent group include a caprolactone divalent modifying group.

Further, the polymerizable compound having a charge transporting structure of the present invention is more preferably a compound having the structure of the following general formula (3).
(Wherein, o, p and q are each an integer of 0 or 1, Ra represents a hydrogen atom or a methyl group, Rb and Rc represent a substituent other than a hydrogen atom and an alkyl group having 1 to 6 carbon atoms, And s and t each represents an integer of 0 to 3. Za is a single bond, a methylene group, an ethylene group,
Represents. )
As the compound represented by the above general formula, a compound having a methyl group or an ethyl group as a substituent for Rb and Rc is particularly preferable.

  The charge transporting compound having a polymerizable functional group represented by the general formulas (1) and (2), particularly (3) used in the present invention is polymerized with the carbon-carbon double bond being released on both sides, so In a polymer that does not become a structure, is incorporated in a chain polymer, and is crosslinked by polymerization with a polymerizable compound that does not have a charge transporting structure, it exists in the main chain of the polymer, and the main chain -Present in a cross-linked chain between main chains (this cross-linked chain includes a main chain portion and a main chain in an intermolecular cross-linked chain between one polymer and another polymer and a folded state in one polymer). There are intramolecular cross-linked chains that are cross-linked with other sites derived from the polymerized monomer at positions away from this in the chain), but they are also present in the cross-linked chain even if they are present in the main chain Even if the triarylamine structure suspended from the chain moiety is in a radial direction from the nitrogen atom It has at least three aryl groups to be arranged and is bulky, but it is not directly bonded to the chain part and is suspended from the chain part via a carbonyl group or the like, so that it has flexibility in steric positioning. Since they are fixed, these triarylamine structures can be arranged in a polymer in a space that is reasonably adjacent to each other, so there is little structural distortion in the molecule, and when the surface layer of the photoreceptor is used. Therefore, it is presumed that an intramolecular structure relatively free from interruption of the charge transport pathway can be taken.

In the present invention, the specific acrylic ester compound represented by the following general formula (4) can also be used favorably as a charge transporting compound having a polymerizable functional group.
In the general formula (4), Ar ₅ represents a monovalent group or a divalent group composed of a substituted or unsubstituted aromatic hydrocarbon skeleton. Examples of the aromatic hydrocarbon include benzene, naphthalene, phenanthrene, biphenyl, 1,2,3,4-tetrahydronaphthalene and the like.
Examples of the substituent include an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, a benzyl group, and a halogen atom. The alkyl group and alkoxy group may further have a halogen atom or a phenyl group as a substituent.
Ar ₆ represents a monovalent group consisting of an aromatic hydrocarbon skeleton having at least one tertiary amino group, a monovalent group consisting of a divalent group or a heterocyclic compound skeleton having at least one tertiary amino group, or Although it represents a divalent group, the aromatic hydrocarbon skeleton having a tertiary amino group is represented by the following general formula (A).

(In general formula (A), R ₁₃ and R ₁₄ represent an acyl group, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group. Ar ₇ represents an aryl group. W is an integer of 1 to 3. Represents.)

Examples of the acyl group for R ₁₃ and R ₁₄ include an acetyl group, a propionyl group, and a benzoyl group.
The substituted or unsubstituted alkyl group for R ₁₃ and R ₁₄ is the same as the alkyl group described for the substituent for Ar ₅ .
The substituted or unsubstituted aryl group for R ₁₃ and R ₁₄ is phenyl group, naphthyl group, biphenylyl group, terphenylyl group, pyrenyl group, fluorenyl group, 9,9-dimethyl-2-fluorenyl group, azulenyl group, anthryl group, In addition to the triphenylenyl group and the chrysenyl group, a group represented by the following general formula (B) can be exemplified.

[In General Formula (B), B is selected from —O—, —S—, —SO—, —SO ₂ —, —CO—, and the following divalent groups.
(Wherein R ₂₁ is a hydrogen atom, a substituted or unsubstituted alkyl group defined by a substituent of Ar ₅ , an alkoxy group, a halogen atom, a substituted or unsubstituted aryl group defined by R ₁₃ , an amino group; , A nitro group, a cyano group, R ₂₂ represents a hydrogen atom, a substituted or unsubstituted alkyl group defined by a substituent of Ar ₅ , a substituted or unsubstituted aryl group defined by R ₁₃ , i Represents an integer of 1 to 12, and j represents an integer of 1 to 3)]

Specific examples of the alkoxy group of R ₂₁ include methoxy group, ethoxy group, 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 and the like.
Examples of the halogen atom for R ₂₁ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
Examples of the amino group of R ₂₁ include a diphenylamino group, a ditolylamino group, a dibenzylamino group, and a 4-methylbenzyl group.
Phenyl group as the aryl group Ar _7, naphthyl group, biphenylyl group, terphenylyl group, pyrenyl group, fluorenyl group, 9,9-dimethyl-2-fluorenyl group, azulenyl group, anthryl group, triphenylenyl group, include a chrysenyl Can do.
Ar _7, R _13, R ₁₄ is an alkyl group as defined Ar _5, an alkoxy group, may have a halogen atom as a substituent.

Examples of the heterocyclic compound skeleton having a tertiary amino group include amines such as pyrrole, pyrazole, imidazole, triazole, dioxazole, indole, isoindole, benzimidazole, benzotriazole, benzisoxazine, carbazole, and phenoxazine. Examples include heterocyclic compounds having a structure. These may have an alkyl group, an alkoxy group, or a halogen atom defined by Ar ₅ as a substituent.
B ₁ and B ₂ represent an acryloyloxy group, a methacryloyloxy group, a vinyl group, an acryloyloxy group, a methacryloyloxy group, an alkyl group having a vinyl group, an acryloyloxy group, a methacryloyloxy group, or an alkoxy group having a vinyl group. As the alkyl group and alkoxy group, those described for Ar ₅ are similarly applied. Both of these B ₁ and B ₂ may be present, or only one of them may be present.

As a more preferable structure in the acrylic ester compound of the general formula (4), a compound of the following general formula (5) can be exemplified.
In the general formula (5), R ₈ and R _{9 each} represents a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group or a halogen atom, and Ar ₇ and Ar ₈ represent a substituted or unsubstituted aryl group or An arylene group and a substituted or unsubstituted benzyl group are represented. As the alkyl group, alkoxy group, and halogen atom, those described for Ar ₅ are similarly applied.
The aryl group is the same as the aryl group defined by R ₁₃ and R ₁₄ . An arylene group is a divalent group derived from the aryl group.
B _{1 to} B ₄ are the same as B ₁ and B ₂ in the general formula (4). u represents an integer of 0 to 5, and v represents an integer of 0 to 4.

  The specific acrylic ester compound has the following characteristics. It is a tertiary amine compound having a stilbene-type conjugated structure, and has a developed conjugated system. By using a charge transporting compound with such a conjugated system, the charge injection property at the interface part of the cross-linked layer becomes very good, and intermolecular interaction is inhibited even when immobilized between cross-linked bonds. It is difficult and has good characteristics with respect to charge mobility. In addition, it has a highly polymerizable acryloyloxy group or methacryloyloxy group in the molecule, and rapidly gels during polymerization and does not cause excessive crosslinking strain. The double bond at the stilbene structure in the molecule partially participates in the polymerization, and the polymerization is lower than the acryloyloxy group or methacryloyloxy group. In addition, since the number of cross-linking reactions per molecular weight can be increased due to the use of double bonds in the molecule, the cross-linking density can be increased, and further improvement in wear resistance can be realized. . In addition, the degree of polymerization of this double bond can be adjusted depending on the crosslinking conditions, and an optimum crosslinked film can be easily produced. Such cross-linking participation in the polymerization is a specific feature of the acrylate compound and does not occur in the α-phenylstilbene type structure as described above.

  In view of the above, by using the charge transporting compound having a polymerizable functional group represented by the general formula (4), particularly the general formula (5), it is possible to maintain good electrical characteristics and to generate cracks and the like. Can form films with extremely high crosslink density, thereby satisfying the various characteristics of the photoreceptor, preventing silica fine particles from sticking to the photoreceptor, and reducing image defects such as white spots. Can do.

  Specific examples of the polymerizable compound having a charge transporting structure used in the present invention are shown below, but are not limited to the compounds having these structures.

  Further, the charge transporting compound having a polymerizable functional group used in the present invention is important for imparting the charge transport performance of the crosslinked surface layer, and this component is 80% by mass or less based on the total amount of the crosslinked surface layer, preferably Content of a coating liquid component is adjusted so that it may become 70 mass% or less. When this component exceeds 80% by mass, the content of the polymerizable compound having no charge transport structure is reduced, resulting in a decrease in the crosslink density, and high wear resistance is not exhibited. Although the electrical characteristics and wear resistance required by the process used are different, it cannot be said unconditionally, but considering the balance of both characteristics, the range of 70% by mass or less is most preferable.

The cross-linked surface layer constituting the photoreceptor of the present invention comprises a functional monomer and a polymerizable oligomer for the purpose of imparting functions such as viscosity adjustment during coating, stress relaxation of the cross-linked surface layer, lower surface energy and reduced friction coefficient. Can be used together. Known functional monomers and polymerizable oligomers can be used. Examples of the functional monomer include those substituted with a fluorine atom such as octafluoropentyl acrylate, 2-perfluorooctylethyl acrylate, 2-perfluorooctylethyl methacrylate, 2-perfluoroisononylethyl acrylate, No. 60503, JP-B-6-45770, siloxane repeating units: 20-70 acryloyl polydimethylsiloxane ethyl, methacryloyl polydimethylsiloxane ethyl, acryloyl polydimethylsiloxane propyl, acryloyl polydimethylsiloxane butyl, diacryloyl polydimethylsiloxane Examples include vinyl monomers having a polysiloxane group such as diethyl, acrylates and methacrylates. Examples of the polymerizable oligomer include epoxy acrylate, urethane acrylate, and polyester acrylate oligomers.
However, if a large amount of monofunctional and bifunctional functional polymerizable monomers or polymerizable oligomers having a low number of functional groups are contained, the three-dimensional cross-linking density of the cross-linked cross-linked surface layer is substantially reduced, and the wear resistance is reduced. Invite. For this reason, these content is 50 mass% or less with respect to the bridge | crosslinking surface layer whole quantity, Preferably it is 30 mass% or less.

In addition, the crosslinked surface layer of the present invention may contain a polymerization initiator in the crosslinked surface layer coating solution for the purpose of improving the reaction efficiency during polymerization, if necessary. Conventionally known thermal polymerization initiators and photopolymerization initiators can be used favorably as the polymerization initiator.
Examples of the thermal polymerization initiator include 2,5-dimethylhexane-2,5-dihydroperoxide, dicumyl peroxide, benzoyl peroxide, t-butylcumyl peroxide, 2,5-dimethyl-2,5-di ( Peroxybenzoyl) hexyne-3, di-t-butyl peroxide, t-butyl hydroperoxide, cumene hydroperoxide, lauroyl peroxide, 2,2-bis (4,4-di-t-butylperoxycyclohexyl) B) Peroxide-based initiators such as propane, azo-based compounds such as azobisisobutylnitrile, azobiscyclohexanecarbonitrile, methyl azobisisobutyrate, azobisisobutylamidine hydrochloride, 4,4′-azobis-4-cyanovaleric acid Initiators are mentioned.

Examples of the photopolymerization initiator include diethoxyacetophenone, 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxy-cyclohexyl-phenyl-ketone, 4- (2-hydroxyethoxy) phenyl- (2 -Hydroxy-2-propyl) ketone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butanone-1, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 2- Acetophenone-based or ketal-based photopolymerization initiators such as methyl-2-morpholino (4-methylthiophenyl) propan-1-one, 1-phenyl-1,2-propanedione-2- (o-ethoxycarbonyl) oxime, Benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isobutyl ether Benzoin ether photopolymerization initiators such as benzoin isopropyl ether, benzophenone, 4-hydroxybenzophenone, methyl o-benzoylbenzoate, 2-benzoylnaphthalene, 4-benzoylbiphenyl, 4-benzoylphenyl ether, acrylated benzophenone, Benzophenone photopolymerization initiators such as 1,4-benzoylbenzene, thioxanthones such as 2-isopropylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2,4-dichlorothioxanthone Examples of photopolymerization initiators and other photopolymerization initiators include ethyl anthraquinone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoic acid. Phenylethoxyphosphine oxide, bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide, bis (2,4-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, methylphenylglyoxyester, 9,10 -Phenanthrene, an acridine type compound, a triazine type compound, an imidazole type compound is mentioned. Moreover, what has a photopolymerization acceleration effect can also be used individually or in combination with the said photoinitiator. Examples thereof include triethanolamine, methyldiethanolamine, ethyl 4-dimethylaminobenzoate, isoamyl 4-dimethylaminobenzoate, (2-dimethylamino) ethyl benzoate, 4,4′-dimethylaminobenzophenone, and the like.
These polymerization initiators may be used alone or in combination of two or more. Content of a polymerization initiator is 0.5-40 mass parts with respect to 100 mass parts of total inclusions which have polymerizability, Preferably it is 1-20 mass parts.

  Furthermore, the coating solution for forming a crosslinked surface layer of the present invention may contain additives such as various plasticizers (for the purpose of stress relaxation and adhesion improvement), leveling agents, and low molecular charge transport materials having no polymerizability. Can be contained. As these additives, known additives can be used, and as plasticizers, those used in general resins such as dibutyl phthalate and dioctyl phthalate can be used, and the amount used is the total solid content of the coating liquid. To 20% by mass or less, preferably 10% by mass or less. As leveling agents, silicone oils such as dimethyl silicone oil and methylphenyl silicone oil, polymers or oligomers having a perfluoroalkyl group in the side chain can be used, and the amount used is based on the total solid content of the coating liquid. On the other hand, 3% by mass or less is appropriate.

  When the polymerizable compound is a liquid, the coating liquid for the crosslinked surface layer of the present invention can be applied by dissolving other components in the liquid, but if necessary, it is diluted with a solvent and applied. . Solvents used at this time include alcohols such as methanol, ethanol, propanol and butanol, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, esters such as ethyl acetate and butyl acetate, tetrahydrofuran, dioxane and propyl ether. And ethers such as dichloromethane, dichloroethane, trichloroethane and chlorobenzene, aromatics such as benzene, toluene and xylene, cellosolves such as methyl cellosolve, ethyl cellosolve and cellosolve acetate. These solvents may be used alone or in combination of two or more. The dilution ratio with the solvent varies depending on the solubility of the composition, the coating method, and the target film thickness, and is arbitrary. The application can be performed by dip coating, spray coating, bead coating, ring coating, or the like.

In the present invention, after applying the coating liquid for the crosslinked surface layer, energy is applied from outside to polymerize to form the crosslinked surface layer. The external energy used at this time includes heat, light, and radiation. . The heat energy is applied by heating from the coating surface side or the support side using a gas such as air or nitrogen, steam, various heat media, infrared rays, or electromagnetic waves. The heating temperature is preferably 80 ° C. or higher and 170 ° C. or lower. When the heating temperature is lower than 80 ° C., the reaction rate is slow and the reaction is not completely completed. At a temperature higher than 170 ° C., the reaction proceeds non-uniformly and a large strain is generated in the crosslinked surface layer. In order to advance the polymerization reaction uniformly, it is also effective to complete the reaction by heating at a relatively low temperature of less than 50 ° C. and then heating to 100 ° C. or more. As the light energy, a UV irradiation light source such as a high-pressure mercury lamp or a metal halide lamp that has an emission wavelength mainly in ultraviolet light can be used, but a visible light source can also be selected according to the absorption wavelength of the polymerizable substance or the photopolymerization initiator. is there. Irradiation light amount is 50 mW / cm ² or more, preferably 500 mW / cm ² or more, more preferably 1000 mW / cm ² or more. By using irradiation light stronger than 1000 mW / cm ^2, the progress rate of the polymerization reaction is significantly increased, and a more uniform crosslinked surface layer can be formed. Examples of radiation energy include those using electron beams. Among these energies, those using heat and light energy are useful because of easy reaction rate control and simple apparatus.

As the crosslinked surface layer, a conventionally known crosslinked surface layer other than the above-described crosslinked surface layer can be used. Specific examples include thermosetting resins and electron beam curable resins. Examples of the thermosetting resin include a compound containing a plurality of active hydrogens (hydrogen such as —OH group, —NH ₂ group and —NH group), a compound containing a plurality of isocyanate groups and / or a plurality of epoxy groups. A thermosetting resin obtained by thermally polymerizing a compound to be used can also be used. In this case, examples of the compound containing a plurality of active hydrogens include acrylic resins containing active hydrogen such as polyvinyl butyral, phenoxy resin, phenol resin, polyamide, polyester, polyethylene glycol, polypropylene glycol, polybutylene glycol, and hydroxyethyl methacrylate groups. System resin and the like.

  Examples of the compound containing a plurality of isocyanate groups include tolylene diisocyanate, hexamethylene diisocyanate, diphenylmethane diisocyanate, and prepolymers thereof. Examples of the compound having a plurality of epoxy groups include bisphenol A type epoxy resin. can give. A thermosetting resin obtained by thermally polymerizing an oil-free alkyd resin and an amino resin such as a butylated melamine resin can also be used as the binder resin. Such a thermosetting resin has high insulating properties, and the film does not elute at the time of coating, so that a uniform film is maintained. Therefore, the stability and uniformity of the antifouling effect are excellent.

  The electron beam curable resin is not particularly limited as long as it can be cured by electron beam irradiation. However, among them, a compound having an unsaturated polymerizable functional group in the molecule is preferable in terms of high reactivity, high reaction rate, and high hardness characteristics achieved by curing by electron beam irradiation. Therefore, in the present invention, the crosslinked surface layer preferably contains a resin obtained by polymerizing or crosslinking a compound having an unsaturated polymerizable functional group in the molecule by electron beam irradiation and curing. Moreover, it is particularly preferable from the viewpoint of high reactivity that the unsaturated polymerizable functional group contains at least one of an acryl group, a methacryl group and a styrene group. The compounds having the unsaturated polymerizable functional group are roughly classified into monomers and oligomers based on the repetition of the structural unit. A monomer is a monomer having no relatively repeating structural unit having an unsaturated polymerizable functional group and having a relatively small molecular weight, and an oligomer is a polymer having a repeating unit having an unsaturated polymerizable functional group and having a number of repeating units of about 2 to 20. It is a coalescence. Moreover, the macromer which has an unsaturated polymerizable functional group only in the terminal of a polymer or an oligomer can also be used as a curable compound for the crosslinked surface layer of the present invention.

  Next, the charging grid of the corona charger according to the present invention will be described. As the base material of the charging grid which is the control electrode of the corona charger, those conventionally used can be used. As a material of the charging grid, a metal which is a conductor is used to function as an electrode. As the electrode function, most metals such as aluminum, nickel, iron, nichrome, copper, zinc and silver can be used, but the charger is exposed to ozone, NOx, etc. generated by corona discharge. A highly metal is preferable, and stainless steel containing chromium or nickel is used. As the shape, it is necessary to move the charge generated by corona discharge onto the photoconductor and to have a function as a control electrode, so that a metal thin plate is provided with an opening by punching, etching or the like, or metal wires are arranged Is usually used. For example, as a base material for a charging grid, a SUS304 plate having a thickness of 0.1 mm, a length of 285 mm, and a width of 40 mm is used, and an opening length of 250 mm and a width of 36 mm is 0.1 mm at a 45 degree angle. Those arranged at intervals of 5 mm can be used. The external shape of this charging grid is shown in FIG. In FIG. 9, 2 is a shield case, and 6 is a charging grid.

  Next, the zeolite used for the coating layer of the corona charger of the present invention will be described. In the present invention, zeolite is used to remove discharge products. Any kind of natural zeolite, synthetic zeolite, artificial zeolite and the like may be used as long as the target substance can be removed. Zeolite is prepared by dealumination using natural zeolite or synthetic zeolite as a starting material, by dealumination using mineral acid, etc., or direct synthesis method in which silica source, alumina source, alkali source and organic mineralizer are mixed and crystallized. Etc. Zeolite differs in the molecule that can be adsorbed because the pore size changes depending on the crystal form and the type of cation in the crystal. Therefore, effective removal is possible by selecting the crystal form and cation species according to the target substance. Crystal types include A, X, Y, L, mordenite, ferrierite, ZSM-5, beta, etc., and cation species include potassium, sodium, calcium, ammonium, hydrogen, etc. However, any of them can be suitably used in the present invention. Further, the adsorption ability and catalytic ability change depending on the ratio of silica and alumina constituting the zeolite, and the target substance can be efficiently removed by selecting the optimum ratio. In the present invention, the silica / alumina ratio is preferably 100 (mol / mol) or less, more preferably 50 (mol / mol) or less.

  The content of zeolite can be favorably used in the range of 30 to 70% by mass, more preferably 40 to 60% by mass with respect to the total mass of the coat layer. When the content of zeolite is less than 30% by mass, the discharge product removal ability may be insufficient, and an abnormal image may be generated due to this. On the other hand, when the content of zeolite exceeds 70% by mass, the resistance value of the charging grid becomes too high, so that the ability to control the surface potential is insufficient and uniform charging may not be possible.

  Next, the conductive agent used for the coat layer of the corona charger of the present invention will be described. A charged grid, which is a processed product of a metal plate, is inherently conductive, but is covered with zeolite and a binder resin, so that the electric resistance increases and does not play a role in controlling the surface potential. Therefore, for the purpose of imparting conductivity, a conductive agent is dispersed in the binder resin. Here, the conductive agent may be graphite, activated carbon, metal such as copper, tin, aluminum, nickel, indium, tin oxide, zinc oxide, titanium oxide, indium oxide, antimony oxide, bismuth oxide, antimony-doped tin oxide, oxidation Examples thereof include fine metal oxide powders such as indium tin and zinc antimonate. In addition, as an ion conductive conductive agent, tetraalkylammonium salt, trialkylbenzyl, ammonium salt, alkylsulfonate, alkylbenzenesulfonate, alkyl sulfate, glycerol fatty acid ester, sorbitan fatty acid ester, polyoxyethylene alkylamine, Polyoxyethylene fatty alcohol ester, alkyl betaine, lithium perchlorate, and the like may be used in combination. Furthermore, a solvent-dispersed sol in which fine particles are dispersed in a solvent can also be used favorably. Since the corona charger is always placed under discharge during use, the conductive agent used is required to have durability against discharge, and metals such as graphite and nickel, and metal oxides such as tin oxide and indium tin oxide are used over time. It is preferable because it is stable against environmental fluctuations. Indium tin oxide is preferably used from the viewpoints of dispersion stability, conductivity, and durability over time of use. In addition, the smaller the content of the conductive agent, the more the conductivity of the film and the discharge product removal function, which are other functions, are not hindered. 0.01 μm to 15 μm is preferably used. Moreover, binder resin which shows electroconductivity can also be used as a electrically conductive agent. In some cases, two kinds of conductive agents can be used.

  The content of the conductive agent can be favorably used in the range of 10 to 50% by mass, more preferably 20 to 40% by mass with respect to the total mass of the coat layer. When the content of the conductive agent is less than 10% by mass, the resistance value of the charging grid cannot be controlled sufficiently low, the surface potential control ability is insufficient, and uniform charging may not be performed. On the other hand, when the content of the conductive agent exceeds 50% by mass, the amount of zeolite contained may be insufficient, and the discharge product removal capability may be insufficient. In this case, an abnormal image due to this may occur.

  Next, the binder resin used for the coating layer of the corona charger of the present invention will be described. As binder resin, polyamide, polyurethane, epoxy resin, polyketone, polycarbonate, silicone resin, acrylic resin, polyvinyl butyral, polyvinyl formal, polyvinyl ketone, polystyrene, polysulfone, poly-N-vinylcarbazole, polyacrylamide, polyvinyl benzal, polyester, Phenoxy resin, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyphenylene oxide, polyamide, polyvinyl pyridine, cellulosic resin, casein, polyvinyl alcohol, polyvinyl pyrrolidone, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, Styrene-maleic anhydride copolymer, polyvinyl chloride, polyvinylidene chloride, polyarate, cellulose acetate resin, ethyl Cellulose resins, polyvinyl toluene, melamine resins, urethane resins, alkyd resins, include thermoplastic or thermosetting resins such as phenol resins, thermosetting resins are preferably used from the viewpoint of durability. Phenol resin is more preferably used from the viewpoint of dispersion stability of zeolite or conductive agent, adhesion and stability of characteristics over time. The phenol resin used in the present invention is generally a resin obtained by the reaction of phenol compounds such as phenol, cresol, xylenol, various bisphenols, various polyphenols and formaldehyde. There are two types of phenolic resins: a resol type obtained by reacting phenols with formaldehyde in excess and using an alkali catalyst, and a phenolic resin in excess of formaldehyde and reacting with acid catalysts. It is divided into the resulting novolac type. In the present invention, either phenol resin can be used, but a resol type phenol resin is preferably used. The resol type is also soluble in alcohol and ketone solvents, and is heated to form a cured product by three-dimensional crosslinking polymerization. In general, resole is used industrially as a varnish for paints, adhesives, castings and laminates. As the phenol resin used in the present invention, any known phenol resin may be used, and one kind or a mixture of two or more kinds of resins may be used.

  As content of binder resin, it can use suitably in 10-30 mass% with respect to the total mass of a coating layer, More preferably, it is 15-25 mass%. When the content of the binder resin is less than 10% by mass, it may not be sufficient to hold the zeolite or the conductive agent on the charging grid, and the good function of the charging grid cannot be maintained over a long period of use. There is a case. On the other hand, when the content of the binder resin exceeds 30% by mass, the content of the zeolite or the conductive agent may be insufficient, and it may not be possible to maintain high reliability even after long-term use.

  When a novolac type phenol resin is used as the binder resin, it is preferable to add a curing agent, and as this curing agent, hexamethylenetetramine or the like can be used. Although it does not specifically limit as content of a hardening | curing agent, It is preferable that it is 5-20 mass parts with respect to 100 mass parts of novolak-type phenol resins. More preferably, it is 7-17 mass parts. When the content of the curing agent is less than the above lower limit, the novolak-type phenol resin is insufficiently cured, and the mechanical strength of the molded product may be lowered. Moreover, when the said upper limit is exceeded, the gas generated by decomposition | disassembly of a hardening | curing agent may swell to a molded article and may generate | occur | produce a crack.

Next, as the solvent used in the coating solution for the coating layer of the corona charger of the present invention, any solvent may be used as long as it has good dispersibility of the zeolite and the conductive agent and dissolves the binder resin well. As used herein, methanol, ethanol, isopropanol, acetone, methyl ethyl ketone, cyclohexanone, tetrahydrofuran, dioxane, toluene, ethyl cellosolve, ethyl acetate, methyl acetate, dichloromethane, dichloroethane, monochlorobenzene, cyclohexane, toluene, xylene, ligroin, etc. Is mentioned. Among these, the use of a non-halogen solvent is desirable for the purpose of reducing the environmental load. These solvents may be used alone or in combination of two or more. The dilution ratio with the solvent varies depending on the solubility of the composition, the coating method, and the target film thickness, and is arbitrary. As a coating method of the coating solution, methods such as dip coating, roller coating, spray coating, beat coating, nozzle coating, and electrophoretic electrodeposition can be used.
The film thickness of the coat layer is preferably 10 μm or more, more preferably 20 μm or more from the viewpoint of durability. If the thickness is 10 μm or less, high reliability may not be maintained for long-term use. The coating layer can be provided on either one side or both sides of the charging grid. However, when applied to only one side, the discharge product removal ability may not be sufficiently maintained, and both sides are required from the viewpoint of sustaining the effect. It is preferable to provide in.

Problems when holding zeolite on the charging grid As described above, the corona charger generates discharge products in addition to corona discharge, of which reactive gases such as O ₃ and NOx are used in the resin over time. Advances material degradation. As a result, detachment of the zeolite on the charging grid occurs, and the discharge product cannot be removed.
In the present invention, by using the above-mentioned zeolite, conductive agent, and binder resin, the functions required for each, specifically, the ability to remove zeolite, the resistance control capability of the conductive agent, and the retention capability of the binder resin are exhibited well. The

  Next, the image forming apparatus will be described first as an explanation of the embodiment of the present invention. FIG. 10 is a schematic diagram of an image forming apparatus. The photoconductor 100 is charged with (±) 600 to 1400 V by the corona charging device 101 according to the present invention. After the charge is applied (charged), the image exposure system 102 forms a latent image. In the case of an analog copying machine, the original image irradiated by the exposure lamp is projected onto the photosensitive member in the form of a reverse image by a mirror and formed into an image. In the case of a digital copying machine, it is read by a CCD (Charge Coupled Device). The obtained original image is converted into a digital signal of an LD or LED having a wavelength of 400 to 780 nm, and formed on the photosensitive member. Therefore, the analog and digital wavelength ranges are different. By image formation, charge separation is performed in the photosensitive layer, and a latent image is formed on the photosensitive member. The photoreceptor 100 on which the latent image is formed according to the document is developed with a developer by the developing device 103, and the document image is visualized (toner image). Next, the toner image on the photoreceptor is transferred to the copy sheet 109 by applying a voltage to the transfer device 104. The voltage applied in the transfer is controlled by constant current so that the current flowing through the photosensitive member is constant. On the other hand, after the transfer, the toner image is cleaned and cleaned by the cleaning device 105 (comprising the cleaning brush 106 and the elastic rubber cleaning blade 107). Since the latent image (original image) after the toner image is formed is held on the photosensitive member after cleaning, the static eliminator (generally using red light) 108 for erasing and uniformizing. Then, the preparation for the next latent image formation is completed and a series of copying processes is completed. The image forming unit may be fixedly incorporated in a copying apparatus, a facsimile machine, or a printer, but may be incorporated in the apparatus in the form of a process cartridge and detachable.

  The process cartridge for an image forming apparatus of the present invention is a process cartridge used for the image forming apparatus described above, and includes a photoconductor having a crosslinked surface layer, in addition to a corona charging device, a developing device, a transfer unit, a cleaning unit, This is an apparatus (part) that includes at least one static elimination unit and is detachable from the main body of the image forming apparatus. An example of the process cartridge is shown in FIG.

<Synthesis Example of Polymerizable Compound Having Charge Transporting Structure>
The polymerizable compound having a charge transporting structure in the present invention is synthesized, for example, by the method described in Japanese Patent No. 3164426. An example of this is shown below.
(1) Synthesis of hydroxy group-substituted triarylamine compound (the following structural formula B) 113.85 g (0.3 mol) of a methoxy group-substituted triarylamine compound (the following structural formula A) and 138 g (0.92 mol) of sodium iodide To this, 240 ml of sulfolane was added and heated to 60 ° C. in a nitrogen stream. In this solution, 99 g (0.91 mol) of trimethylchlorosilane was added dropwise over 1 hour and stirred at a temperature of about 60 ° C. for 4 and a half hours to complete the reaction. About 1.5 L of toluene was added to the reaction solution, cooled to room temperature, and washed repeatedly with water and an aqueous sodium carbonate solution. Thereafter, the solvent was removed from the toluene solution and purified by column chromatography (adsorption medium: silica gel, developing solvent: toluene: ethyl acetate = 20: 1). Cyclohexane was added to the obtained pale yellow oil to precipitate crystals. In this way, 88.1 g of a white crystal of the following structural formula B was obtained. (Yield = 80.4% melting point: 64.0-66.0 ° C.) Elemental analysis results are shown below.

(2) Synthesis of Triarylamino Group-Substituted Acrylate Compound (Exemplary Compound No. 54) 82.9 g (0.227 mol) of the hydroxy group-substituted triarylamine compound (Structural Formula B) obtained in (1) above was added to 400 ml of tetrahydrofuran. In a nitrogen stream, an aqueous sodium hydroxide solution (NaOH: 12.4 g, water: 100 ml) was added dropwise. The solution was cooled to 5 ° C., and 25.2 g (0.272 mol) of acrylic acid chloride was added dropwise over 40 minutes. Then, it stirred at 5 degreeC for 3 hours, and reaction was complete | finished. The reaction solution was poured into water and extracted with toluene. This extract was repeatedly washed with an aqueous sodium bicarbonate solution and water. Thereafter, the solvent was removed from the toluene solution and purified by column chromatography (adsorption medium: silica gel, developing solvent: toluene). N-Hexane was added to the obtained colorless oil to precipitate crystals. Thus, Exemplified Compound NO. As a result, 80.73 g of 54 white crystals were obtained. (Yield = 84.8%, melting point: 117.5 to 119.0 ° C.) Elemental analysis results are shown below.

(3) Synthesis example of acrylic ester compound (Preparation of diethyl 2-hydroxybenzylphosphonate)
Into a reaction vessel equipped with a stirrer, thermometer, and dropping funnel, 38.4 g of 2-hydroxybenzyl alcohol (manufactured by Tokyo Chemical Industry) and 80 ml of o-xylene are placed, and triethyl phosphite (manufactured by Tokyo Chemical Industry Co., Ltd.) in a nitrogen stream. 62.8 g was slowly added dropwise at 80 ° C., and the reaction was further carried out at the same temperature for 1 hour. Thereafter, the produced ethanol, the solvent o-xylene, and unreacted triethyl phosphite were removed by distillation under reduced pressure to obtain 66 g of diethyl 2-hydroxybenzylphosphonate. (Boiling point 120.0 ° C./1.5 mmHg) (yield 90%)

(Preparation of 2-hydroxy-4 ′-(N, N-bis (4-methylphenyl) amino) stilbene)
Into a reaction vessel equipped with a stirrer, a thermometer, and a dropping funnel, 14.8 g of potassium tert-butoxide and 50 ml of tetrahydrofuran were placed. Under a nitrogen stream, 9.90 g of diethyl 2-hydroxybenzylphosphonate and 4- (N, N A solution in which 5.44 g of -bis (4-methylphenyl) amino) benzaldehyde was dissolved in tetrahydrofuran was slowly added dropwise at room temperature, and then reacted at the same temperature for 2 hours. Thereafter, water was added under water cooling, and then 2N hydrochloric acid aqueous solution was added for acidification. Tetrahydrofuran was removed by an evaporator, and the crude product was extracted with toluene. The toluene phase was washed with water, an aqueous sodium hydrogen carbonate solution and saturated brine in this order, and dehydrated by adding magnesium sulfate. After filtration, toluene was removed to obtain an oily crude product, which was further purified with silica gel and then crystallized in hexane to give 5.09 g of 2-hydroxy-4 ′-(N, N-bis). (4-Methylphenyl) amino) stilbene was obtained. (Yield 72%, melting point 136.0-138.0 ° C.)

(Preparation of 4 ′-(N, N-bis (4-methylphenyl) amino) stilben-2-yl acrylate)
In a reaction vessel equipped with a stirrer, a thermometer, and a dropping funnel, 14.9 g of 2-hydroxy-4 ′-(N, N-bis (4-methylphenyl) amino) stilbene, 100 ml of tetrahydrofuran, 12% concentration of hydroxide 21.5 g of an aqueous sodium solution was added, and 5.17 g of acrylic acid chloride was added dropwise over 5 minutes at 5 ° C. under a nitrogen stream. Then, it was made to react at the same temperature for 3 hours. The reaction solution was poured into water, extracted with toluene, concentrated and subjected to column purification with silica gel. The obtained crude product was recrystallized with ethanol, and yellow needle-like 4 ′-(N, N-bis (4-methylphenyl) amino) stilben-2-yl acrylate (Exemplary Compound NO. 105) 13. 5 g was obtained. (Yield 79.8%, melting point 104.1-105.2 ° C.) Elemental analysis results are shown below.

  As described above, a number of 2-hydroxystilbene derivatives are synthesized by reacting 2-hydroxybenzylphosphonic acid ester derivatives with various amino-substituted benzaldehyde derivatives. An ester compound can be synthesized.

Hereinafter, although an example is given and the present invention is explained, the present invention is not restricted by these examples. All parts are parts by mass.
[Example 1]
After coating on a 360 mm long, φ100 mm aluminum cylinder using a coating solution for charge blocking layer having the following composition, drying was performed at 130 ° C. for 20 minutes to form a charge blocking layer of about 0.5 μm. Subsequently, after applying using a coating solution for a moire preventing layer having the following composition, drying was performed at 130 ° C. for 30 minutes to provide a 3.5 μm moire preventing layer. Subsequently, after coating using a coating solution for charge generation layer having the following composition, drying was performed at 100 ° C. for 20 minutes to form a charge generation layer of about 0.2 μm. Furthermore, after coating using a coating solution for a charge transport layer having the following composition, drying was performed at 130 ° C. for 20 minutes to form a charge transport layer having a thickness of about 20 μm. All the coatings so far used the dip coating method. After applying the coating solution for the crosslinked surface layer having the following composition by spray coating on the photoreceptor obtained as described above, using a UV lamp system manufactured by Ushio, photocuring is performed with a UV irradiation time of 60 seconds, Further, a crosslinked surface layer of about 7 μm was provided by drying at 70 ° C./30 minutes.

(Charge blocking layer coating solution)
N-methoxymethylated nylon (Lead City, FR101): 5 parts Methanol: 70 parts n-Butanol: 30 parts (moire prevention layer coating solution)
Titanium oxide (manufactured by Ishihara Sangyo Co., Ltd., CR-EL): 126 parts Alkyd resin (manufactured by Dainippon Ink & Chemicals, Beckolite M6401-50-S):
33.6 parts Melamine resin (Dainippon Ink Chemical Industries, Super Becamine L-121-60):
18.7 parts 2-butanone: 100 parts (coating liquid for charge generation layer)
Y-type titanyl phthalocyanine: 6 parts Silicone resin solution (manufactured by Shin-Etsu Chemical, KR5240): 70 parts Methyl ethyl ketone: 200 parts

(Coating liquid for charge transport layer)
Polycarbonate Z polycarbonate (manufactured by Teijin Chemicals): 10 parts Charge transporting compound represented by the following structural formula: 7 parts
Tetrahydrofuran: 80 parts Silicone oil (manufactured by Shin-Etsu Chemical Co., Ltd., KF50-100cs): 0.002 parts

(Coating liquid for crosslinked surface layer)
Trifunctional acrylic resin (manufactured by Nippon Kayaku, KAYARAD TMPTA): 10 parts Polymerizable compound having a charge transporting structure (exemplary compound number: NO. 54): 10 parts
Polymerization initiator 1-hydroxy-cyclohexyl-phenyl-ketone (Ciba Specialty Chemicals, Irgacure 184): 1 part Tetrahydrofuran: 50 parts

  Next, a method for manufacturing the charging grid used in the examples will be described. As a base material for the charging grid, a SUS304 plate having a thickness of 0.1 mm, a length of 285 mm, and a width of 40 mm was used, and an opening length of 250 mm and a width of 36 mm were set to a 0.1 mm grid of 0.5 mm at an angle of 45 degrees. What was arranged at intervals was used. The coating solution is prepared by first preparing a binder resin with a solid content concentration of 5 to 10 wt% with respect to an arbitrary solvent, and adding the zeolite particles and the conductive agent while stirring the binder solution. The solid content concentration of the coating solution was prepared to be 30 wt% or less. Spray coating is selected as the coating method. Tension is applied from both ends in the long axis direction of the charging grid, and the charging grid is tensioned and fixed so as not to sag. A cylindrical base with a diameter of 30 mm The cylinder was rotated at a speed of 100 rpm in the circumferential direction. Spray coating was performed by scanning the spray device at a speed of 10 mm / sec in the horizontal direction with respect to the longitudinal direction of the cylindrical substrate. In order to coat both sides of the charging grid, the charging grid was set up about 3 mm above the base, and after the spray coating on one side was finished, the other side was spray coated in the same manner. After spray coating, it was heated at 150 ° C. for 60 minutes using a dryer to obtain a charged grid of the present invention. The coating film thickness on the charging grid was about 40 μm.

As the coating solution for the charging grid of Example 1, a coating solution having the following composition was used.
(Charging grid coating solution)
Beta type, hydrogen-containing zeolite (Tosoh, 980HOA): 13 parts Indium tin oxide (Sumitomo Metal Mining, SUFP, primary particle size: 0.02-0.04 μm): 7 parts Resol type phenolic resin (Gunei Chemical Industry) Manufactured by PL-4804): 5 parts Ethanol: 60 parts

[Example 2]
A photoconductor and a charging grid of Example 2 were produced in the same manner as in Example 1 except that the coating solution for the crosslinked surface layer and the coating solution for the charging grid of Example 1 were changed as follows.
(Coating liquid for crosslinked surface layer)
Trifunctional acrylic resin (manufactured by Nippon Kayaku, KAYARAD TMPTA): 5 parts 5.5 functional acrylic resin (manufactured by Nippon Kayaku, KAYARAD DPHA): 5 parts Polymerizable compound having a charge transporting structure (exemplary compound number: NO. 54): 10 parts Polymerization initiator (manufactured by Tokyo Chemical Industry, 2,4-diethylthioxanthone): 1 part Tetrahydrofuran: 50 parts (coating solution for charging grid)
Beta type, hydrogen-containing zeolite (manufactured by Tosoh, 980HOA): 13 parts Indium tin oxide (manufactured by JEMCO, ITO, primary particle diameter: 0.03 μm): 7 parts 5 parts Curing agent (hexamethylenetetramine): 0.25 parts Methanol: 60 parts

[Example 3]
A photoconductor and a charging grid of Example 3 were produced in the same manner as in Example 1 except that the coating solution for the crosslinked surface layer and the coating solution for the charging grid of Example 1 were changed as follows.
(Coating liquid for crosslinked surface layer)
Trifunctional acrylic resin (manufactured by Nippon Kayaku, KAYARAD TMPTA): 5 parts 6 functional acrylic resin (manufactured by Nippon Kayaku, KAYARAD DPCA-120): 5 parts Polymerizable compound having a charge transporting structure (exemplary compound number: NO. 54): 10 parts Polymerization initiator (manufactured by Tokyo Chemical Industry, 2-methyl-1 [4- (methylthio) phenyl] -2-
Morifolinopropan-1-one): 1 part Tetrahydrofuran: 50 parts (coating solution for charging grid)
Beta type, hydrogen-containing zeolite (manufactured by Tosoh, 980HOA): 13 parts Indium tin oxide (manufactured by JEMCO, EI, primary particle size: 0.03 μm): 7 parts Resol type phenolic resin (manufactured by Gunei Chemical Industry, PL-4852) : 5 parts 2-Propanol: 60 parts

[Example 4]
A photoconductor and a charging grid of Example 4 were produced in the same manner as in Example 1 except that the coating solution for the crosslinked surface layer and the coating solution for the charging grid of Example 1 were changed as follows.
(Coating liquid for crosslinked surface layer)
Trifunctional acrylic resin (manufactured by Nippon Kayaku, KAYARAD TMPTA): 5 parts Quadrifunctional acrylic resin (manufactured by Kayaku Sartomer, SR-295): 5 parts Polymerizable compound having a charge transporting structure (exemplary compound number: NO.54) ): 10 parts Polymerization initiator (manufactured by Tokyo Chemical Industry, phenylbis (2,4,6-trimethylbenzoyl)
Phosphine oxide): 1 part Tetrahydrofuran: 50 parts (coating solution for charging grid)
Beta type, hydrogen-containing zeolite (manufactured by Tosoh, 980HOA): 13 parts Indium tin oxide (manufactured by JEMCO, PI, primary particle size: 0.03 μm): 7 parts Resol type phenol resin (manufactured by Gunei Chemical Industry, PL-2407) : 5 parts Ethanol: 60 parts

[Example 5]
A photoconductor and a charging grid of Example 5 were produced in the same manner as in Example 1 except that the coating solution for the crosslinked surface layer and the coating solution for the charging grid in Example 1 were changed as follows.
(Coating liquid for crosslinked surface layer)
Tetrafunctional acrylic resin (manufactured by Kayaku Sartomer, SR-355): 5 parts Polymerizable compound having a charge transporting structure (exemplary compound number: NO. 54): 10 parts Polymerization initiator (Tokyo Chemical Industry, 2-hydroxy- 2-Methyl-1-phenyl-propane-
1-one): 1 part Tetrahydrofuran: 50 parts (coating solution for charging grid)
Beta-type, hydrogen-containing zeolite (manufactured by Tosoh, 980HOA): 13 parts Indium tin oxide (Ci Kasei, NanoTek Powder, primary particle size: 0.03 μm):
7 parts Resol type phenol resin (manufactured by Gunei Chemical Industry Co., Ltd., PL-2211): 5 parts Methanol: 60 parts

[Example 6]
A photoconductor and a charging grid of Example 6 were produced in the same manner as in Example 1 except that the coating solution for the crosslinked surface layer and the coating solution for the charging grid of Example 1 were changed as follows.
(Coating liquid for crosslinked surface layer)
Trifunctional acrylic resin (manufactured by Nippon Kayaku, KAYARAD TMPTA): 5 parts Hexafunctional acrylic resin (manufactured by Nippon Kayaku, KAYARAD DPCA-60): 5 parts Polymerizable compound having a charge transporting structure (exemplary compound number: NO. 105): 10 copies
Polymerization initiator (Tokyo Chemical Industry, benzoin isopropyl ether): 1 part Tetrahydrofuran: 50 parts (coating solution for charging grid)
Beta type, hydrogen-containing zeolite (manufactured by Tosoh, 980HOA): 13 parts Indium tin oxide (CI Kasei, NanoTekSlurry): 7 parts Resol type phenolic resin (manufactured by Dainippon Ink & Chemicals, Pryofen 5010):
5 parts 2-propanol: 60 parts

[Example 7]
A photoconductor and a charging grid of Example 7 were produced in the same manner as in Example 1 except that the coating solution for the crosslinked surface layer and the coating solution for the charging grid of Example 1 were changed as follows.
(Coating liquid for crosslinked surface layer)
Trifunctional acrylic resin (manufactured by Nippon Kayaku, KAYARAD TMPTA): 5 parts Multifunctional acrylic resin (manufactured by Shin-Nakamura Chemical Co., Ltd., U15HA 15 functional): 5 parts Polymerizable compound having a charge transporting structure (Exemplary compound number: NO.106) ): 10 parts Polymerization initiator (manufactured by Tokyo Chemical Industry, benzophenone): 1 part Tetrahydrofuran: 50 parts (coating solution for charging grid)
Beta type, hydrogen-containing zeolite (manufactured by Tosoh, 980HOA): 13 parts activated carbon (manufactured by Kuraray Chemical, RP-20): 7 parts resol type phenolic resin (manufactured by Dainippon Ink and Chemicals, Pryofen 5030-40k): 5 parts ethanol : 60 copies

[Example 8]
A photoconductor and a charging grid of Example 8 were prepared in the same manner as in Example 1 except that the coating solution for the crosslinked surface layer and the coating solution for the charging grid of Example 1 were changed as follows.
(Coating liquid for crosslinked surface layer)
Trifunctional acrylic resin (Nippon Kayaku, KAYARAD TMPTA): 5 parts Multifunctional acrylic resin: 5 parts (Nippon Kayaku, KAYARAD DPHA40H bifunctional)
Polymerizable compound having charge transporting structure (Exemplary compound number: NO. 106): 10 parts Polymerization initiator (Tokyo Chemical Industry, 2-chlorothioxanthone): 1 part Tetrahydrofuran: 50 parts (coating solution for charging grid)
Beta type, hydrogen-containing zeolite (manufactured by Tosoh, 980HOA): 13 parts Tin oxide (Mitsubishi Materials, S2000): 7 parts Resol type phenolic resin (Dainippon Ink & Chemicals, Pryofen TD-447): 5 parts Methanol: 60 copies

[Example 9]
The photoreceptor and charging grid of Example 9 were the same as Example 1 except that the charge blocking layer of Example 1 was not provided and the coating solution for the crosslinked surface layer and the coating solution for the charging grid were changed as follows. Produced.
(Coating liquid for crosslinked surface layer)
Trifunctional acrylic resin (manufactured by Nippon Kayaku, KAYARAD TMPTA): 5 parts Multifunctional acrylic resin (manufactured by Toa Gosei, M7100 trifunctional or higher): 5 parts Polymerizable compound having a charge transporting structure (Exemplary Compound No .: NO.180) ): 10 copies
Polymerization initiator (Tokyo Kasei Co., Ltd., benzoin): 1 part Tetrahydrofuran: 50 parts (coating solution for charging grid)
Beta type, hydrogen-containing zeolite (manufactured by Tosoh, 980HOA): 13 parts Zinc antimonate (manufactured by Nissan Chemical Industries, Celnax CX-Z210IP): 7 parts : 5 parts 2-Propanol: 60 parts

[Example 10]
A photoreceptor and a charging grid of Example 10 were produced in the same manner as in Example 9, except that the coating solution for the crosslinked surface layer and the coating solution for the charging grid of Example 9 were changed as follows.
(Coating liquid for crosslinked surface layer)
Trifunctional acrylic resin (manufactured by Nippon Kayaku Co., Ltd., KAYARAD TMPTA): 5 parts Polyfunctional acrylic resin (manufactured by Toa Gosei, M8530 trifunctional or higher): 5 parts Polymerizable compound having a charge transporting structure (exemplary compound number: NO.180) ): 10 parts Polymerization initiator (manufactured by Tokyo Chemical Industry, benzoin ethyl ether): 1 part Tetrahydrofuran: 50 parts (coating solution for charging grid)
Beta type, hydrogen-containing zeolite (manufactured by Tosoh, 980HOA): 13 parts Zinc antimonate (manufactured by Nissan Chemical Industries, Celnax CX-Z210IP): 7 parts Oil-free alkyd resin (manufactured by Dainippon Ink and Chemicals, Beckolite 46-118) ):
3 parts Melamine resin (manufactured by Dainippon Ink and Chemicals, Super Becamine G-821-60):
2 parts Methyl ethyl ketone: 60 parts

[Example 11]
A photoconductor and a charging grid of Example 11 were produced in the same manner as in Example 9, except that the coating solution for the crosslinked surface layer and the coating solution for the charging grid of Example 9 were changed as follows.
(Coating liquid for crosslinked surface layer)
Trifunctional acrylic resin (manufactured by Nippon Kayaku, KAYARAD TMPTA): 5 parts Multifunctional acrylic resin (manufactured by Toa Gosei, M8560): 5 parts Polymerizable compound having a charge transporting structure (exemplary compound number: NO. 180): 10 Part polymerization initiator (manufactured by Tokyo Chemical Industry, 1- [4- (2-hydroxyethoxy) -phenyl]-
2-hydroxy-2-methyl-1-propan-1-one): 1 part Tetrahydrofuran: 50 parts (coating solution for charging grid)
Beta-type, hydrogen-containing zeolite (Tosoh, 980HOA): 13 parts Indium tin oxide (Sumitomo Metal Mining, SUFP, primary particle size: 0.02-0.04 μm): 7 parts Polycarbonate resin (Mitsubishi Gas Chemical, Iupilon) Z300): 5 parts Tetrahydrofuran: 60 parts

[Example 12]
An electrophotographic photosensitive member and a charged grid were produced in the same manner as in Example 1 except that the crosslinked surface layer of Example 1 was produced as follows in accordance with Example 1 of Japanese Patent No. 3826639.
(Method for producing crosslinked surface layer)
10 parts of a compound described in the structural formula below, 18 parts of a curable siloxane resin (Shin-Etsu Silicon, X-40-2239), tin oxide fine particles doped with antimony (T-1, manufactured by Mitsubishi Metals Co., Ltd., primary particle size 0. (01 μm) 8 parts of the mixture was dispersed with a paint shaker for 5 hours, and then 7 parts of acetic acid and 0.001 part of 1N hydrochloric acid were added to obtain a coating solution for a crosslinked surface layer. This coating solution was dip-coated on the charge transport layer, and after 30 minutes of finger drying, a heat treatment was performed at 120 ° C. for 2 hours to provide a crosslinked surface layer having a thickness of about 5 μm.

[Example 13]
An electrophotographic photosensitive member and a charged grid were prepared in the same manner as in Example 1 except that the crosslinked surface layer of Example 1 was prepared as follows in accordance with Example 1 of JP-A-2006-139309.
(Method for producing crosslinked surface layer)
The molecular sieve 4A was added to 10 parts of a polysiloxane resin (containing 1% by mass of silanol groups) consisting of 80 mol% of methylsiloxane units and 20 mol% of methyl-phenylsiloxane units, and the mixture was allowed to stand for 15 hours for dehydration treatment. This resin was dissolved in 10 parts of toluene, and 5 parts of methyltrimethoxysilane and 0.2 part of dibutyltin acetate were added thereto to make a uniform solution. Further, 6 parts of dihydroxymethyltriphenylamine described below was added and mixed, and this solution was applied and dried at 120 ° C. for 1 hour to provide a crosslinked surface layer having a thickness of about 1 μm.

[Example 14]
According to Example 1 of Japanese Patent No. 4143497 on the charge generation layer of Example 1, an electrophotographic photosensitive member and a charging grid were prepared in the same manner as Example 1 except that a crosslinked surface layer was provided as follows (crosslinked surface). Layer production method)
60 parts of a hole transporting compound monomer having the following structural formula was dissolved in a mixed solvent of 30 parts of monochlorobenzene and 30 parts of dichloromethane to prepare a coating solution for a crosslinked surface layer. This coating solution was dip coated on the charge generation layer, and then irradiated with an electron beam under the conditions of an acceleration voltage of 150 kV and an irradiation dose of 10 Mrad in an atmosphere having an oxygen concentration of 10 ppm. Subsequently, a heat treatment was carried out for 10 minutes under the same atmosphere at a temperature of 80 ° C. to provide a crosslinked surface layer having a thickness of 15 μm.

[Comparative Example 1]
A photoreceptor and a charging grid of Comparative Example 1 were prepared in the same manner as in Example 1 except that the crosslinked surface layer of Example 1 was not provided and the charge transport layer was 27 μm.
[Comparative Example 2]
A photoreceptor and a charging grid of Comparative Example 2 were obtained in the same manner as in Example 1 except that the coating liquid was not applied to the charging grid of Example 1.

[Comparative Example 3]
A photoreceptor and a charging grid of Comparative Example 3 were obtained in the same manner as in Example 1 except that the coating solution for charging grid of Example 1 was changed as follows.
(Charging grid coating solution)
Indium tin oxide (Sumitomo Metal Mining, SUFP, primary particle size: 0.02-0.04 μm): 7 parts Resol type phenolic resin (manufactured by Gunei Chemical Industry Co., Ltd., PL-4804): 5 parts Ethanol: 30 parts

[Comparative Example 4]
A photoreceptor and a charging grid of Comparative Example 4 were obtained in the same manner as in Example 1 except that the coating solution for charging grid of Example 1 was changed as follows.
(Charging grid coating solution)
Beta-type, hydrogen-containing zeolite (manufactured by Tosoh, 980HOA): 13 parts Resol-type phenol resin (manufactured by Gunei Chemical Industry, PL-4804): 5 parts Ethanol: 45 parts

[Comparative Example 5]
A photoreceptor and a charging grid of Comparative Example 4 were obtained in the same manner as in Example 1 except that the coating solution for charging grid of Example 1 was changed as follows.
(Charging grid coating solution)
Beta-type, hydrogen-containing zeolite (Tosoh, 980HOA): 13 parts Indium tin oxide (Sumitomo Metal Mining, SUFP, primary particle size: 0.02-0.04 μm): 7 parts Ethanol: 50 parts [Comparative Example 6]
A photoreceptor and a charging grid of Comparative Example 6 were obtained in the same manner as in Example 12 except that the coating solution was not applied to the charging grid of Example 12.
[Comparative Example 7]
A photoreceptor and a charging grid of Comparative Example 7 were obtained in the same manner as in Example 13 except that the coating liquid was not applied to the charging grid of Example 13.
[Comparative Example 8]
A photoreceptor and a charging grid of Comparative Example 8 were obtained in the same manner as in Example 14 except that the coating solution was not applied to the charging grid of Example 14.

The following evaluations were performed on the photoreceptors and charging grids of Examples 1 to 14 and Comparative Examples 1 to 8 manufactured as described above. Shown with results.
(Film adhesion evaluation)
As an evaluation of the adhesion of the coating film formed on the charging grid for the photoreceptors and charging grids of Examples 1 to 14 and Comparative Examples 1 to 5, the coated surface of the charging grid was rubbed ten times strongly with a waste cloth. The degree of coating film peeling when the case was wiped 10 times with a load sufficient to place a finger was evaluated. Moreover, after discharging a corona charger for 200 hours as durability evaluation, it evaluated similarly. The evaluation results are performed in four stages, and the respective levels are shown below.
◎: Even if rubbed strongly, it does not adhere to the waste. ○: A small amount adheres to the waste, but it can withstand actual use. △: A little amount adheres to the waste but can withstand actual use. When rubbed, it adheres to the waste and cannot withstand actual use.

  Examples 1, 3 to 9, 12 to 14 and Comparative Examples 1, 3, and 4 using a resol type phenol resin as a charging grid coating solution have good film adhesion even after 200 hours of discharge. . Compared with these, in Example 2 using the novolac type phenol resin, the adhesion is slightly inferior after 200 hours of discharge. Furthermore, in Examples 10 and 11 using alkyd melamine resin or polycarbonate, the adhesion was further deteriorated. It can be seen that Comparative Example 5 containing no binder resin has poor adhesion from the beginning and cannot withstand actual use.

(Charge controllability evaluation)
The photosensitive grids of Examples 1 to 14 and Comparative Examples 1 to 4 and 6 to 8 were attached to an imagio Neo 1050pro having a process cartridge placed in a 10 ° C. and 15% RH environment. Corona discharge was performed by applying a voltage so that a constant current would flow through the charging wire, and the surface potential of the photoconductor when -900 V was applied to the charging grid was measured. After that, a halftone image was output, and the presence or absence of raindrop-like density unevenness that occurred at the time of local charging failure was confirmed. Moreover, even after discharging the corona charger for 200 hours as durability evaluation, the presence or absence of raindrop-like density unevenness was confirmed. The evaluation results are performed in three stages, and the respective levels are shown below.
◎: Raindrop unevenness does not occur ○: Raindrop unevenness slightly occurs, but acceptable level ×: Raindrop unevenness occurs

  Examples 1 to 6, 12 to 14, and Comparative Examples 1 and 3 using phenol resin and indium tin oxide as the coating solution for the charging grid are good without causing raindrop-like density unevenness even after 200 hours of discharge. is there. Moreover, the favorable result is obtained also in the comparative example 2 which has not applied to the charging grid. In Examples 7 to 10 in which the conductive agent of the charging grid coating solution is not indium tin oxide, raindrop-like density unevenness is slightly observed after 200 hours of discharge. This is presumably because the dispersibility of the conductive agent is deteriorated as compared with the combination of indium tin oxide and a phenol resin, and the conductive durability expected for the conductive agent is reduced. In Comparative Example 4 containing no conductive agent, an abnormal image was generated from the initialization, and the surface potential of the photoconductor was much higher than the charged grid voltage, indicating that the charge controllability was remarkably inferior.

(Evaluation of discharge product removal function)
The photosensitive grids of Examples 1 to 14 and Comparative Examples 1 to 3 and 6 to 8 were attached to an imagio Neo 1050pro having a process cartridge placed in a 10 ° C. and 15% RH environment. After performing the image forming operation, the corona charger was discharged for 3 hours, the machine was turned off, and the photoconductor and the charging grid were left standing for 15 hours. Thereafter, the machine was turned on again, and a halftone was output to evaluate density unevenness directly under the corona charger. Moreover, after discharging a corona charger for 200 hours as durability evaluation, the density nonuniformity was also evaluated. The evaluation results are performed in four stages, and the respective levels are shown below.
○: Concentration unevenness directly under the corona charger does not occur △: Concentration unevenness directly under the corona charger occurs, but acceptable level ×: Concentration unevenness directly under the corona charger occurs clearly, and is not acceptable

  In Examples 1 to 14 and Comparative Example 1 of the present invention, density unevenness is within an allowable level even after 200 hours of discharge. In Comparative Examples 2, 6, 7, and 8 in which the charging grid is not coated and in Comparative Example 3 in which the charging grid coating solution does not contain zeolite, density unevenness occurs from the beginning, and the discharge product is removed. The result was not done.

(Real machine accelerated fatigue evaluation)
The photoreceptors and charging grids of Examples 1 to 14 and Comparative Example 1 are mounted on a process cartridge as shown in FIG. 11, mounted in a tandem type full-color image forming apparatus as shown in FIG. 12, and an image exposure light source is 780 nm. A semiconductor laser (image writing by a polygon mirror), a scorotron charger as a charger, a transfer belt as a transfer member, and a 780 nm LED as a charge removal light source were used. As process conditions before the test, the photosensitive member charging potential was set to −800 V and the developing bias was set to −500 V. As a sheet-passing condition, a chart having a writing rate of 6% (characters equivalent to 6% as an image area are written on the entire A4 surface) was continuously printed on 2 million sheets. The evaluation was performed by measuring the unexposed portion potential of the photoreceptor and the exposed portion potential before and after printing 2 million images. As a measuring method, a surface potential meter is mounted at the developing portion position shown in FIG. 11, the photosensitive member is fixed to an applied bias charged to −800 V in the initial state, and the surface potential of the unexposed portion at the developing portion position and the exposure are fixed. The surface potential was measured. Further, the difference in film thickness (amount of wear) before and after all tests was evaluated. The film thickness was measured at intervals of 1 cm, excluding 5 cm at both ends in the longitudinal direction of the electrophotographic photosensitive member, and the average value was taken as the film thickness. Furthermore, after printing 2 million sheets, an all-white image was output, and the stain on the background portion was evaluated. The image evaluation of the background portion was carried out in four stages, and an extremely good one was indicated by ◎, a good one by ○, a slightly inferior by Δ, and a very bad one by ×. Further, after printing 2 million sheets, an ISO / JIS-SCID image N1 (portrait) was output to evaluate the color color reproducibility. The color reproducibility evaluation was carried out in 4 stages. Very good ones were indicated by ◎, good ones were indicated by ○, slightly inferior ones were indicated by Δ, and very bad ones were indicated by ×.

In Examples 1 to 14 having a crosslinked surface layer, the photoreceptor surface potential fluctuation is small even after printing 2 million sheets, and the background stain and color balance image characteristics are also good. It can be seen that, among Examples 1 to 8, in which a charge blocking layer is provided on the photoreceptor, the background stain is very good. Further, in Example 1, a trifunctional acrylic resin is used, but in Examples 2 to 11 in which an acrylic resin having a larger number of functional groups is used, the amount of wear of the photoconductor is small, and further, a pentafunctional or higher functional acrylic resin is used. In Examples 3 and 6, the wear amount is smaller and high wear resistance is realized. In Examples 9 to 11, the wear resistance is further improved by using a polymerizable compound having a bifunctional charge transporting structure. On the other hand, in Examples 12 to 14, the polymerization energy source of the crosslinked surface layer is heat or an electron beam, and polymerization is performed without ultraviolet rays, but also high abrasion resistance and stable image output are achieved. In Comparative Example 1 in which no cross-linked surface layer is provided, the wear amount of the photoconductor is remarkably large, and the fluctuation of the photoconductor surface potential accompanying this is also large, and the image characteristics are remarkably impaired.
Accordingly, it has a photoreceptor having the crosslinked surface layer of the present invention, and the charging grid surface of the corona charger for charging the photoreceptor has a coating layer containing at least zeolite, a conductive agent and a binder resin. In an image forming apparatus that maintains high durability, contamination of the environment and the photoreceptor can be significantly suppressed, thereby realizing an extremely reliable image forming apparatus that can maintain extremely stable electrical characteristics over a long period of time. It became clear.

It is explanatory drawing of a structure of a corona charger. (A: corotron type corona charger, b: scorotron type corona charger) It is a graph which shows the charging characteristic in each charging system. (A: corotron type corona charger, b: scorotron type corona charger) Shows density unevenness directly under the corona charger. It is explanatory drawing which shows the electric potential at the time of image flow generation | occurrence | production. It is explanatory drawing of an example of the structural example of the photoconductor of this invention. It is explanatory drawing of the other structural example of the photoconductor of this invention. It is explanatory drawing of the other structural example of the photoconductor of this invention. It is explanatory drawing of the other structural example of the photoconductor of this invention. It is a figure which shows the general-view shape of the charging grid of this invention. 1 is a schematic diagram of an image forming apparatus of the present invention. It is a schematic diagram of the process cartridge of the present invention. 1 is a schematic diagram of a tandem full-color image forming apparatus.

Explanation of symbols

(About FIGS. 5-8)
31: Conductive support 33: Photosensitive layer 35: Charge generation layer 37: Charge transport layer 39: Crosslinked surface layer 41: Intermediate layer (about FIG. 9)
2: Shield case 6: Charging grid (FIG. 10)
DESCRIPTION OF SYMBOLS 100: Photoconductor 101: Charging device 102: Image exposure system 103: Developing device 104: Transfer device 105: Cleaning device 106: Cleaning brush 107: Cleaning blade 108: Static elimination device 109: Copy paper (about FIG. 11)
101: photosensitive member 102: charging member 103: laser beam 104: developing member 105: recording medium 107: cleaning member 108: transfer member (about FIG. 12)
1C, 1M, 1Y, 1K: photoreceptors 2C, 2M, 2Y, 2K: charging members 3C, 3M, 3Y, 3K: laser beams 4C, 4M, 4Y, 4K: developing members 5C, 5M, 5Y, 5K: transfer members 6C, 6M, 6Y, 6K: Cleaning member 7: Conveyance transfer belt 8: Recording medium 9: Fixing member

Claims (12)

  An image forming apparatus comprising: a photoreceptor having a crosslinked surface layer; and a charging grid surface of a corona charger for charging the photoreceptor having a coat layer containing at least zeolite, a conductive agent and a binder resin.   2. The function-separated type photoreceptor in which the photoreceptor is provided on a conductive support in the order of a charge blocking layer, a moire preventing layer, a charge generation layer, a charge transport layer, and a crosslinked surface layer. The image forming apparatus described.   The image forming apparatus according to claim 1, wherein the conductive agent is indium tin oxide.   The image forming apparatus according to claim 1, wherein the binder resin is a phenol resin.   The image forming apparatus according to claim 1, wherein the phenol resin is a resol type.   6. The image forming apparatus according to claim 1, wherein the crosslinked surface layer is formed by photocuring.   The image forming apparatus according to claim 6, wherein the photocuring is performed by ultraviolet rays.   The image according to any one of claims 1 to 7, wherein the crosslinked surface layer is formed using a coating liquid containing a polymerizable compound having no tri- or higher functional charge transporting structure. Forming equipment.   The image according to any one of claims 1 to 8, wherein the cross-linked surface layer is formed using a coating liquid containing a polymerizable compound having no pentafunctional or higher functional charge transporting structure. Forming equipment.   The image forming apparatus according to claim 1, wherein the cross-linked surface layer is formed using a coating liquid containing a polymerizable compound having a mono- or higher functional charge transporting structure. .   The image forming apparatus according to claim 1, wherein the cross-linked surface layer is formed using a coating liquid containing a polymerizable compound having a bifunctional or higher functional charge transport structure. .   A process cartridge for use in the image forming apparatus according to any one of claims 1 to 11, wherein the latent image forming device forms an electrostatic latent image on the surface of the photosensitive member charged by at least a corona charger; A developing unit that attaches toner to the electrostatic latent image formed by the latent image forming unit, a transfer unit that transfers the toner image formed by the developing unit to a transfer target, and a toner that remains on the surface of the photosensitive member after transfer A process cartridge for an image forming apparatus, wherein the process cartridge is manufactured by combining one or more cleaning devices to be removed from the surface of a photoconductor and a photoconductor, and is detachable from an image forming apparatus main body.