JP2008158353A - Cleaning device, process cartridge, and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cleaning device capable of preventing swarf remaining on the surface of a cleaning roll during its manufacturing process from sticking to an image carrier, thereby removing local charging failure and image defects resulting from the sticking of swarf, and to provide a process cartridge and image forming apparatus that use the cleaning device. <P>SOLUTION: The cleaning device includes a first roll capable of being brought into contact with the image carrier, and a second roll capable of being brought into contact with the first roll. The second roll has a resin foam body on the outer periphery of a core material. The surface of the resin foam body contains a material having releasing property. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a cleaning device, a process cartridge, and an image forming apparatus. In particular, the present invention relates to a cleaning device that can be suitably used to remove toner adhering to the surface of a charging member of an image forming apparatus such as an electrophotographic copying machine or a laser beam printer, a process cartridge including the cleaning device, and an image The present invention relates to a forming apparatus.

  An electrophotographic image forming apparatus is faster than a conventionally used area by greatly improving the sensitivity and extending the life of an image carrier (hereinafter sometimes referred to as “electrophotographic photosensitive member” or “photosensitive member”). , Its application is spreading to high-quality areas.

  In an image forming apparatus, image formation is performed using a photosensitive member through processes such as charging, exposure, development, transfer, and cleaning. For example, Patent Document 1 proposes a cleaning member in which a contact portion with a cleaning object is made of a melamine resin foam.

  Further, in Patent Document 2, regarding cleaning of the surface of a roll such as a contact charging roll that comes into contact with the image carrier, a resin foam such as a porous sponge roll (hereinafter referred to as a cleaning roll) is brought into contact with the contact charging roll around. In addition, it is disclosed to remove deposits attached to the surface of the contact charging roll. However, in the manufacturing process of a roll (sponge roll) having a resin foam, if the cutting powder of the roll remains on the roll, the cutting powder is transferred to the roll in the image forming process, and as a result, the roll surface is locally localized. Cause poor charging and image defects such as color spots.

JP 2003-66807 A JP-A-5-297690

  The present invention aims to solve the above problems. That is, the present invention provides a cleaning device capable of preventing adhesion of cutting powder remaining on the roll surface during the cleaning roll manufacturing process to the charging member and the image holding member, and to improve local charging defects and image defects associated therewith. The purpose is to provide. Another object of the present invention is to provide a process cartridge and an image forming apparatus using the cleaning device.

The present invention has been solved by means described in the following <1>, <5>, and <6>. It is described below together with <2> to <4> which are preferred embodiments.
<1> A first roll that can contact the image holding member and a second roll that can contact the first roll, and the second roll has a resin foam on the outer periphery of the core member. And a cleaning device characterized in that the surface of the resin foam contains a releasable material,
<2> The cleaning device according to <1>, wherein the first roll is a contact charging roll,
<3> The cleaning device according to <1> or <2>, wherein the material having releasability is a resin containing fluorine,
<4> The cleaning device according to any one of <1> to <3>, wherein the surface of the image carrier contains a siloxane-based resin,
<5> A process cartridge that includes at least an image carrier, a charging roll, and a cleaning unit that removes the developer attached to the surface of the charging roll, and is detachable from an image forming apparatus. A process cartridge, wherein the means is the cleaning device according to any one of <1> to <4>;
<6> At least the image carrier, charging means for charging the surface of the image carrier, exposure means for exposing the surface of the image carrier to form a latent image, and the latent image carried on the developer carrier. An image forming apparatus comprising: a developing unit that develops with a developer; a transfer unit that transfers a developed image to a transfer target; and a cleaning unit that removes residual toner on the charging member. > To <4> An image forming apparatus according to any one of the above.

  According to the present invention, it is possible to provide a cleaning device capable of preventing adhesion of cutting powder remaining on a roll surface to a charging member during a cleaning roll manufacturing process and improving local charging failure and image defect associated therewith. it can. Furthermore, according to the present invention, a process cartridge and an image forming apparatus using the cleaning device can be provided.

(Cleaning device)
The cleaning device of the present invention includes a first roll that can contact the image carrier and a second roll that can contact the first roll, and the second roll is foamed with resin on the outer periphery of the core material. And the resin foam surface contains a material having releasability.
In the present invention, the first roll is preferably a contact charging roll.

The present invention relates to cleaning of the surface of a roll such as a contact charging roll that can come into contact with an image carrier. Conventionally, a resin foam (preferably a resin foam having an open cell structure such as a porous sponge roll) (in order to clean a roll member (first roll) that can come into contact with such an image carrier ( The second roll) is brought into contact with the contact charging roll around the door and the deposits adhered to the surface of the contact charging roll are removed. However, in the manufacturing process of the second roll having the resin foam, cutting powder such as abrasive powder remains on the roll and inside the foam. When the cutting powder on the second roll is transferred to the first roll in the image forming step, when the first roll is a charging roll, a local charge failure occurs on the surface, and image defects such as a color point, etc. cause. Further, if the cutting powder further transfers from the first roll to the image carrier, development failure occurs, and as a result, image defects are caused.
In particular, when the releasability of the contact charging roll is lowered due to the charging history, such cutting powder transfer occurs, and it is difficult to remove such cutting powder with the accompanying cleaning roller.
In the present invention, since the second roll surface contains a material having releasability, it is greatly suppressed that the cutting powder remaining on the second roll surface adheres to the first roll and / or the image carrier. Image defects based on local charging failure and development failure can be reduced. As a result, it is possible to obtain a stable image over a long period of time.

FIG. 1 is an explanatory view showing a preferred embodiment of the cleaning device of the present invention. 2 is a perspective view showing a second roll of the cleaning device shown in FIG. FIG. 3 is a schematic cross-sectional view of the second roll shown in FIG. 2 in the II-II line direction.
As shown in FIG. 1, the cleaning device 10 of the present invention has a first roll 14 that can contact the image carrier 12 and a second roll 16 that can contact the first roll. In the present invention, the image carrier 12 is preferably cylindrical, and the first roll 14 and the second roll 16 are preferably arranged to rotate following each other.

Referring to FIGS. 2 and 3, in the present invention, the second roll 16 includes a rod-like support portion 3 and a contact portion 5 formed on the outer peripheral surface of the support portion 3.
The support part 3 is a columnar rod-shaped member. The material in particular of the support part 3 is not restrict | limited, For example, materials, such as a metal or resin, are mentioned. In addition, when the support part 3 is comprised from resin, according to the objective, you may provide electroconductivity, for example by containing an electroconductive substance. As the support part 3, for example, a shaft is used.

The contact portion 5 is formed on the outer peripheral surface of the support portion 3 with a substantially uniform film thickness and has a substantially cylindrical shape. The contact portion 5 is made of a resin foam, and in the present invention, the surface of the resin foam contains a material having releasability. In the present invention, the resin foam is preferably a resin foam having an open cell structure.
Although the film thickness of the contact part 5 can be suitably selected according to the objective, it is preferable that they are 1 mm or more and 50 mm or less, and it is more preferable that they are 1 mm or more and 15 mm or less.
The radius of the entire second roll is preferably 2 mm or more and 100 mm or less, and more preferably 2 mm or more and 40 mm or less.

In the present invention, as the material having releasability, a known material generally used for the purpose of improving releasability can be appropriately used. In this invention, the material which has mold release property may be used individually by 1 type, and may use 2 or more types together.
Examples of the material having releasability include a release resin, a release agent, and other materials.

<Release resin>
Examples of the release resin include polyolefin resins such as polyethylene, polypropylene, chlorinated polyethylene and chlorosulfonated polyethylene; polyvinyl and polyvinylidene resins such as polystyrene and acrylic resins (for example, polymethyl methacrylate, polyacrylonitrile, polyvinyl acetate, polyvinyl alcohol). , Polyvinyl butyral, polyvinyl chloride, polyvinyl carbazole, polyvinyl ether and polyvinyl ketone; vinyl chloride-vinyl acetate copolymer; styrene-acrylic acid copolymer; silicone resin such as straight silicone resin composed of organosiloxane bond or its Modified products (for example, modified products by alkyd resin, polyester, epoxy resin, polyurethane, etc.); Fluorine resin, for example polytetrafluoroethylene Ren, polyvinyl fluoride, polyvinylidene fluoride, and copolymers such as polychlorotrifluoroethylene; and the like.

<Release agent>
As the release agent, various waxes generally used as a release agent can be used.
Specific examples of the release agent include low molecular weight polyolefins such as polyethylene, polypropylene and polybutene; silicones having a softening point by heating; fatty acid amides such as oleic acid amide, erucic acid amide, ricinoleic acid amide and stearic acid amide Plant waxes such as carnauba wax, rice wax, candelilla wax, tree wax, jojoba oil; animal waxes such as beeswax; minerals such as montan wax, ozokerite, ceresin, paraffin wax, microcrystalline wax, and Fischer-Tropsch wax -Petroleum waxes; ester waxes such as fatty acid esters, montanic acid esters, and carboxylic acid esters. In this invention, these mold release agents may be used individually by 1 type, and may use 2 or more types together.

<Other materials>
As other materials, graphite, molybdenum disulfide, silicones having a softening point by heating, and modified products thereof may be used alone or in combination.

Various fine particles can also be used as a material having releasability.
Examples of the fine particles include fluorine-based fine particles such as ethylene tetrafluoride, trifluoride ethylene, propylene hexafluoride, vinyl fluoride, vinylidene fluoride, and the “Proceedings of the 8th Polymer Materials Forum Lecture”, page 89. Examples thereof include fine particles made of a resin obtained by copolymerizing a fluororesin (resin containing fluorine) described later and a monomer having a hydroxyl group.
Also, ZnO—Al ₂ O ₃ , SnO ₂ —Sb ₂ O ₃ , In ₂ O ₃ —SnO ₂ , ZnO—TiO ₂ , ZnO—TiO ₂ , MgO—Al ₂ O ₃ , FeO—TiO ₂ , TiO ₂ , Examples thereof include semiconductive metal oxides such as SnO ₂ , In ₂ O ₃ , ZnO, and MgO.

Among these, it is preferable that the material having releasability is a resin containing fluorine.
The fluorine-containing resin is not particularly limited. For example, polyvinyl fluoride, polyvinylidene fluoride (PVDF), tetrafluoroethylene (TFE) resin, chlorotrifluoroethylene (CTFE) resin, ethylene-tetrafluoro Ethylene copolymer (ETFE), CTFE-ethylene copolymer, PFA (TFE-perfluoroalkyl vinyl ether copolymer), FEP (TFE-hexafluoropropylene (HFP) copolymer), EPE (TFE-HFP-par) Fluoroalkyl vinyl ether copolymer) and the like.
The fluorine-containing resin (fluorine resin) particles are used by being dispersed in a resin material. The resin material includes an aliphatic polyester resin in which polymer segments are linearly bonded, and a soft segment in the molecule. Examples thereof include polyurethane resin and fluororubber. Since these resin materials have flexibility in themselves, the resin foam surface can be provided with flexibility.
It is also possible to use the fluororesin particles dispersed in a resin foam.

The resin foam is formed from a generally well-known synthetic resin. Examples of suitable resins as raw materials include thermoplastic resins such as polyethylene, polyvinyl chloride, polystyrene, polyvinyl alcohol, viscose and ionomer, or urethane resins, rubbers, epoxy resins, phenol / urea resins, and melamine resins. , Thermosetting resins such as pyranyl resin, silicone resin, and acrylic resin.
As the raw material resin, a thermosetting resin is preferable in terms of its hardness and durability, and among the thermosetting resins, a urethane resin, a melamine resin, and the like are more preferable.

Here, when the raw material is a urethane resin, any hydrophobic or hydrophilic polyol can be used as the polyol component, but from the viewpoint of economy and handling properties, polypropylene glycol and an ethylene oxide adduct polyether-based polyol. Etc. are preferably used.
On the other hand, as the isocyanate component, 2,6-toluene diisocyanate (TDI), 4,4′-diphenylmethane diisocyanate (MDI), paraphenylmethane diisocyanate (PPMDI), paraphenylene diisocyanate (PPDI), 1,5-naphthalene diisocyanate ( NDI), 3,3-dimethyldiphenyl-4,4′-diisocyanate (TODI) and the like. Of these, MDI and TDI are preferably used from the viewpoints of economy and handleability.

  In order to enhance the effect, the resin foam preferably contains various other additives in addition to the above-described constituent materials. For example, an antioxidant for reducing the influence of an oxidizing substance incorporated in the network structure of the resin foam, an anti-degradation agent, and improved slipperiness between the second cleaning roll 16 and the first cleaning roll 14 And a lubricant for the purpose.

  As the antioxidant and the deterioration preventing agent, the same antioxidant and deterioration preventing agent as those generally added to the photoreceptor of the image forming apparatus for the purpose of improving the oxidation resistance can be used. Specifically, examples of the antioxidant include hindered phenol, hindered amine, paraphenylenediamine, arylalkane, hydroquinone, spirochroman, spiroidanone and their derivatives, organic sulfur compounds, organic phosphorus compounds, and the like. Antioxidants are relatively often used.

  More specifically, 2,6-di-t-butyl-4-methylphenol, styrenated phenol, n-octadecyl-3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) -Propionate, 2,2'-methylene-bis- (4-methyl-6-t-butylphenol), 2-t-butyl-6- (3'-t-butyl-5'-methyl-2'-hydroxybenzyl) ) -4-methylphenyl acrylate, 4,4′-butylidene-bis- (3-methyl-6-tert-butyl-phenol), 4,4′-thio-bis- (3-methyl-6-tert-butylphenol) ), 1,3,5-tris (4-t-butyl-3-hydroxy-2,6-dimethylbenzyl) isocyanurate, tetrakis- [methylene-3- (3 ′, 5′-di-t-butyl-) 4'-hydroxy - phenyl) propionate] - methane, and the like. These antioxidants and deterioration inhibitors are preferably added in the range of 0.01 wt% to 20 wt% based on the total weight of the resin foam.

  As the lubricant, solid lubricants such as zinc stearate, copper stearate, magnesium palmitate and zinc oleate can be used.

When manufacturing a resin foam, first, the above-described resin and other necessary materials (inorganic particles, antioxidant, etc.) are mixed.
And the obtained mixture is inject | poured into a metal mold | die and it heat-hardens and manufactures a resin foam. The second roll can be manufactured using a mold in which a shaft is set or a cylindrical mold. Thus, when formed into a predetermined shape together with the production of the resin foam, it can be used as the contact portion 5 in the same shape.
Further, if necessary, a processing such as cutting and polishing the molded body is performed.

When the resin foam is a urethane resin foam, a one-shot method or a prepolymer method can be used (for example, see the latest polyurethane material and applied technology, CM Publishing, supervised by Katsuharu Matsunaga).
For example, in the one-shot method, a polyol, tolylene diisocyanate, a catalyst, a surfactant and water, and a conductive material for imparting conductivity, if necessary, and other additives are mixed and stirred at the same time. The foamed reaction mixture is poured into a mold and heat-cured at about 50 ° C. to 90 ° C. for several hours to produce a resin foam.
In the prepolymer method, first, a prepolymer is prepared from a polyol and tolylene diisocyanate. Next, the resulting prepolymer, the same or different polyol, catalyst, surfactant and water as in the prepolymer preparation, and other additives as necessary are mixed and stirred at the same time. Then, using this foamed reaction mixture, a resin foam is produced in the same manner as the one-shot method.

  When the resin foam is a melamine resin foam, a catalyst, an emulsifier and the like are generally blended with melamine and formaldehyde which are main raw materials, and a foaming agent is added and mixed. Then, it can manufacture by methods, such as irradiating an electron beam.

  As the resin foam, it is more preferable that the foam structure is a three-dimensional network structure as described in JP-A-2003-66807. Here, the “three-dimensional network structure” refers to a structure in which fine sub-micron order fibrous resins are three-dimensionally linked in a finely intertwined state to form fine cells.

  In addition, when making a resin foam into a three-dimensional network structure, it can form as follows, for example. That is, the resin to be foamed and the resin dissolved in the specific solvent are sufficiently kneaded and thermally cured, and then immersed in the specific solvent to obtain a three-dimensional network structure in which only the foamed resin portion remains.

In the present invention, the resin foam surface contains a material having releasability.
The material having releasability can be mixed with the resin material when forming the resin foam, or the material having releasability can be coated after forming the resin foam.
When adding a material having releasability when forming the resin foam, it is preferable to add 10 parts by weight or more and 50 parts by weight or less with respect to 100 parts by weight of the resin of the resin foam. It is more preferable to add 40 parts by weight or less. It is preferable that the addition amount of the material having releasability is within the above range since the releasability of the second roll is good and adhesion of cutting powder or the like to the first roll can be effectively suppressed.

As a method for coating a resin foam surface with a releasable material, a blade coating method, a wire bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method, a curtain coating method, etc. This method can be used.
For example, a layer having a thickness of preferably 3 μm or more and 60 μm or less, more preferably 5 μm or more and 30 μm or less can be formed by a spray method. When the film thickness is 3 μm or more, the resin foam is not exposed due to abrasion of the surface layer, which is preferable. Moreover, when forming a surface layer with the apply | coating method, since a uniform film thickness can be formed, it is preferable. On the other hand, it is preferable that the film thickness is 60 μm or less because a liquid pool hardly forms on the surface and a smooth and uniform coating film along the three-dimensional network structure can be stably formed.

As the composition for spray coating, a resin in which releasable / lubricating fine particles such as a fluororesin and an acrylic resin are dispersed in a resin, or a hard coating agent such as silicon or acrylic can be used.
Specifically, as the releasable / lubricating fine particles, those described above can be used.
Further, an aqueous dispersion of a modified resin containing a fluororesin as an essential component can be applied or dipped on the resin surface.

An aqueous dispersion of a modified resin containing a fluororesin for treating the surface layer as an essential component will be described.
Fluorocarbon resins include tetrafluoroethylene homopolymers or copolymers of tetrafluoroethylene and olefins, fluorine-containing olefins, perfluoroolefins, fluoroalkyl vinyl ethers, vinylidene fluoride homopolymers or vinylidene fluoride and olefins, fluorine-containing Examples thereof include copolymers with olefins, perfluoroolefins, fluoroalkyl vinyl ethers, homopolymers of chlorotrifluoroethylene, and copolymers of chlorotrifluoroethylene with olefins, fluorine-containing olefins, perfluoroolefins, fluoroalkyl vinyl ethers, and the like. In particular, a homopolymer or copolymer of tetrafluoroethylene is preferable, and it is also preferable to use a mixture of tetrafluoroethylene homopolymer and various copolymers in a weight ratio of 95: 5 to 10:90.
The modified resin containing a fluorine-based resin as an essential component is used as an aqueous dispersion, and the aqueous dispersion may further contain a wax and / or silicone. By containing wax and / or silicone, it is preferable to promote the penetration of the fluororesin into the resin foam. Here, examples of the wax include paraffin wax, microcrystalline wax, and perotratam. Examples of the silicone include silicone oil, silicone grease, oil compound, and silicone varnish.
For aqueous dispersions of modified resins containing fluorine resin as an essential component, fluorine-based or other nonionic, cationic, anionic or amphoteric surfactants, pH adjusters, solvents, polyhydric alcohols, flexible An agent, a viscosity modifier, a light stabilizer, an antioxidant and the like can also be mixed.

Another preferred embodiment of the second roll will be described with reference to FIG. FIG. 4 is a schematic cross-sectional view showing another preferred embodiment of the second roll that can be used in the present invention.
The second roll shown in FIG. 4 includes a support portion 3, an adhesive portion 4 formed on the outer peripheral surface of the support portion 3, and a contact portion 5 formed on the outer peripheral surface of the adhesive portion 4. Is provided.
The support part 3 and the contact part 5 of the second roll shown in FIG. 4 can have the same configuration as the support part 3 and the contact part 5 shown in FIG. Moreover, the adhesion part 4 can be comprised using resin normally used. Such an adhesive part 4 makes it possible to improve the adhesion between the support part 3 and the contact part 5 and to adjust the elasticity of the second roll. In addition, the adhesion part 4 may be comprised from several layers.
In the present invention, the material having releasability may be contained at least on the surface of the contact portion 5. Moreover, the material which has mold release property may contain both the adhesion part 4 and the contact part 5. FIG. Moreover, after forming the 2nd roll which has an adhesion part, you may coat the material which has mold release property on the 2nd roll surface by the spray coating method mentioned above.

  The second roll is not limited to the above-described embodiment. For example, a resin foam containing a releasable material or further containing inorganic particles is formed into a sheet shape, and the sheet-shaped resin foam is used as the second roll. Alternatively, it may be configured by wrapping around a shaft on which a resin-containing layer is formed. Moreover, you may comprise the strip which cut | disconnected the sheet-like resin foam on the shaft, and you may comprise in roll shape.

(Image forming apparatus and process cartridge)
5 and 6 are schematic views showing the basic configuration of a preferred embodiment of the image forming apparatus of the present invention. An image forming apparatus 100 shown in FIG. 5 exposes a photosensitive member (image holding member) 110, a charging device 120 that charges the photosensitive member 110 by a contact method, and the charged electrophotographic photosensitive member 110 to form an electrostatic latent image. An exposure device 130 for forming, a developing device 140 for developing a toner image by developing an electrostatic latent image, a transfer device 150 for transferring a toner image developed on the photoconductor 110 by the developing device 140 to a transfer medium, A photoconductor cleaning device (hereinafter also simply referred to as a cleaning device) 170 for cleaning the photoconductor 110 after transfer and a fixing device 160 are provided. In the image forming apparatus 100, the photoconductor 110 has a cylindrical shape, and the exposure device 130, the developing device 140, the transfer device 150, and the cleaning device 170 are arranged in this order along the circumferential direction of the photoconductor 110. . Further, the transfer material is transported to a transfer device by a transport roll 180.

  Referring to FIG. 6, the photoconductor 110, which is an image carrier, is rotationally driven with a predetermined peripheral speed in the arrow R1 direction. The charging roll 122 as a direct charging member is in contact with the outer peripheral surface of the photoconductor 110 with a predetermined pressing force. In this example, the rotation of the photoconductor 110 in the direction of arrow R1 causes the arrow R2 to rotate. Rotate following direction. A predetermined bias voltage is applied to the charging roll 122 by a power source (not shown). In this way, the entire outer peripheral surface of the photoconductor 110 is uniformly charged to a predetermined potential by the charging roll 122.

Next, the uniformly charged surface on the outer periphery of the photoconductor 110 is exposed to an optical image by an exposure laser from the exposure device 130 (laser exposure path is indicated by 135). An electrostatic latent image corresponding to the information is formed.
Next, the developer (toner) is attached to the electrostatic latent image in the developing device 140 to develop the toner. This toner image is transferred from the photosensitive member 110 to the recording material conveyed by the conveyance roll 180 from a paper supply unit (not shown) by the transfer device 150 at an appropriate timing. Further, the recording material that has passed through the transfer device is conveyed to the fixing device 160.
After the image transfer, the photoconductor 110 is cleaned by the photoconductor cleaning device 170 to remove adhering contaminants such as residual toner, and is repeatedly used for image formation.

  5 and 6, the photoconductor cleaning device is a blade cleaning system, and the front edge portion of the cleaning blade 171 is brought into contact with the surface movement direction of the photoconductor 110 with a predetermined pressing force in the counter direction. I'm allowed. The contact edge portion of the blade 171 wipes and removes toner remaining on the outer peripheral surface of the photoconductor 110 to clean the surface of the photoconductor 110. The cleaning blade 171 is generally coated with polyvinylidene fluoride, which is a solid lubricant at the time of manufacture, so as to prevent so-called blade turning during initial use of the apparatus.

  The above-described charging roll 122 is accommodated and accommodated in a concave portion provided at the bottom of the cleaning device so as to be rotatably supported by a bearing, and a cleaning roll 123 is disposed in the vicinity thereof as a cleaning member for the charging roll. In the image forming apparatus of this example, four process devices including the photosensitive member 110, the charging roller 122, the developing device 140, and the photosensitive member cleaning device 170 are collectively attached to the main body of the image forming device as a process cartridge 200 that is detachable. It is preferable to simplify the maintenance of the apparatus.

  Hereinafter, the image carrier (photoconductor) 110 will be described in detail. 7 and 8 are schematic cross-sectional views each showing a preferred example of the photoreceptor. The photoreceptor shown in FIG. 7 includes a photosensitive layer 113 in which functions are separated into a layer containing a charge generation material (charge generation layer 115) and a layer containing a charge transport material (charge transport layer 116). . In FIG. 8, the charge generation material and the charge transport material are contained in the same layer (single-layer type photosensitive layer 118). The photosensitive layer may basically have a single-layer structure or a laminated structure in which functions are separated into the charge generation layer 115 and the charge transport layer 116. In the case of a stacked structure, the charge generation layer 115 and the charge transport layer 116 may be stacked in any order.

The electrophotographic photoreceptor 110 shown in FIG. 7 has a structure in which an undercoat layer 114, a charge generation layer 115, a charge transport layer 116 and a protective layer 117 are sequentially laminated on a conductive support 112. 8 has a structure in which an undercoat layer 114, a single-layer type photosensitive layer 118, and a protective layer 117 are sequentially laminated on a conductive support 112. The photoconductor 110 shown in FIG. The electrophotographic photosensitive member 110 may be one without the undercoat layer 114 and / or the protective layer 117.
Hereinafter, each element of the photoreceptor 110 will be described.

  As the conductive support 112, a metal drum or metal sheet made of a metal such as aluminum, copper, iron, stainless steel, zinc, or nickel; aluminum, copper, gold, or the like on a substrate such as a sheet, paper, plastic, or glass; Metals such as silver, platinum, palladium, titanium, nickel-chromium, stainless steel, copper-indium, etc. deposited and conductively treated; Conductive metal compounds such as indium oxide and tin oxide deposited on the substrate, metal Conductive treatment by laminating foil; conductive treatment by dispersing and applying carbon black, indium oxide, tin oxide-antimony oxide powder, metal powder, copper iodide, etc. on a binder resin on the substrate. Can be mentioned. The conductive support 112 is used in a drum shape, a sheet shape, a plate shape, or the like, and is preferably a drum shape.

In addition, as the conductive support 112, conductive fine particles such as carbon black particles, metal fine powder, and metal oxide fine particles dispersed in a binder resin are formed into a pipe shape by centrifugal molding or extrusion molding. Plastic substrates can also be used.
When a metal pipe substrate is used as the conductive support 112, the surface thereof may remain as a raw tube. Note that the metal pipe base material may be subjected in advance to a process such as mirror cutting, etching, anodizing, rough cutting, centerless grinding, sand blasting, wet honing, and the like.
The conductive support 112 is preferably a metal pipe made of an aluminum alloy. The aluminum alloy used as the conductive support 112 can be anodized. As the aluminum, either a pure aluminum system or an aluminum alloy can be used. For example, JIS 1000 series, 3000 series, 6000 series aluminum or aluminum alloy is suitable. The anodized film is obtained by anodizing various metals and various alloys in an electrolyte solution. As such a film, a film called alumite formed when aluminum or an aluminum alloy is anodized in an electrolyte solution is suitable. The alumite film has a high carrier blocking property, and is particularly excellent in preventing point defects (black spots and background stains) that occur when used in reversal development (negative / positive development). Further, it is also excellent in that a current leakage phenomenon from a contact charger that easily occurs during contact charging can be prevented.

The undercoat layer 114 includes a binder resin and an organometallic compound. The undercoat layer 114 has functions such as improvement of wettability when the upper layer is applied and enhancement of blocking property.
Examples of the binder resin used for the undercoat layer 14 include acetal resins such as polyvinyl butyral, polyvinyl alcohol resin, casein, polyamide resin, cellulose resin, gelatin, polyurethane resin, polyester resin, methacrylic resin, acrylic resin, and polyvinyl chloride. Examples thereof include polymer resin compounds such as resins, polyvinyl acetate resins, vinyl chloride-vinyl acetate-maleic anhydride resins, silicone resins, silicone-alkyd resins, phenol-formaldehyde resins, melamine resins. Examples of the organometallic compound used for the undercoat layer 14 include organometallic compounds containing zirconium, titanium, aluminum, manganese, silicon atoms, and the like. These compounds can be used alone or as a mixture or polycondensate of a plurality of compounds.

Among the above, the organometallic compound is preferably an organometallic compound containing zirconium or silicon. An organometallic compound containing zirconium or silicon is excellent in performance such as low residual potential, little potential change due to environment, and little potential change due to repeated use.
The organometallic compounds can be used alone or in admixture of two or more or with the binder resin described above.
Examples of the organic silicon compound include vinyltrimethoxysilane, γ-methacryloxypropyl-tris (β-methoxyethoxy) silane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, and γ-glycidoxy. Propyltrimethoxysilane, vinyltriacetoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) ) -Γ-aminopropylmethylmethoxysilane, N, N-bis (β-hydroxyethyl) -γ-aminopropyltriethoxysilane, γ-chloropropyltrimethoxysilane, and the like.
Particularly preferable organic silicon compounds include vinyltriethoxysilane, vinyltris (2-methoxyethoxysilane), 3-methacryloxypropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 2- (3,4- Epoxycyclohexyl) ethyltrimethoxysilane, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane, N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-aminopropyltriethoxysilane, Examples include silane coupling agents such as N-phenyl-3-aminopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, and 3-chloropropyltrimethoxysilane.

  Examples of the organic zirconium compound include zirconium butoxide, zirconium zirconium acetoacetate, zirconium triethanolamine, acetylacetonate zirconium butoxide, ethyl acetoacetate butoxide, zirconium acetate, zirconium oxalate, zirconium lactate, zirconium phosphonate, zirconium octoate, Zirconium naphthenate, zirconium laurate, zirconium stearate, zirconium isostearate, methacrylate zirconium butoxide, stearate zirconium butoxide, isostearate zirconium butoxide and the like.

  Examples of the organic titanium compound include tetraisopropyl titanate, tetranormal butyl titanate, butyl titanate dimer, tetra (2-ethylhexyl) titanate, titanium acetylacetonate, polytitanium acetylacetonate, titanium octylene glycolate, and titanium lactate ammonium salt. , Titanium lactate, titanium lactate ethyl ester, titanium triethanolamate, polyhydroxy titanium stearate and the like.

  Examples of the organoaluminum compound include aluminum isopropylate, monobutoxy aluminum diisopropylate, aluminum butyrate, diethyl acetoacetate aluminum diisopropylate, and aluminum tris (ethyl acetoacetate).

As the undercoat layer 114, a metal oxide having an appropriate resistance value is dispersed in the binder resin to appropriately adjust the resistance value of the coating film, thereby preventing the accumulation of residual charges and having a certain film thickness. There is also a type of undercoat layer (dispersion type undercoat layer) that improves the leak resistance of the photoreceptor, particularly the ability to prevent leaks during contact charging. In this case, by dispersing the resistance control agent, the film can be made thicker than the above-described structure, and can be used with a thicker film thickness.
Examples of the dispersion-type undercoat layer include metal powders such as aluminum, copper, nickel, and silver, conductive metal oxides such as antimony oxide, indium oxide, tin oxide, and zinc oxide, carbon fiber, carbon black, and graphite powder. And a conductive material dispersed in a binder resin and applied on the conductive support 12.

As the conductive metal oxide, fine particles having an average particle size of 0.5 μm or less are preferably used. Here, the particle size means an average primary particle size. The undercoat layer needs to have an appropriate resistance for obtaining leak resistance. Therefore, the metal oxide fine particles need a powder resistance of about 10 ² Ω · cm to 10 ¹¹ Ω · cm. .
Among metal oxide particles, it is preferable to use metal oxide fine particles such as tin oxide, titanium oxide, and zinc oxide having the above resistance values. In addition, when the resistance value of the metal oxide fine particles is lower than the lower limit value of the above range, sufficient leak resistance tends to be difficult to obtain. On the other hand, if the value is higher than the upper limit of the above range, there is a concern that the residual potential is increased.
Moreover, 2 or more types of metal oxide fine particles can also be mixed and used. Furthermore, the resistance of the powder can be controlled by subjecting the metal oxide fine particles to a surface treatment with a coupling agent. As the coupling agent that can be used for the surface treatment, the same materials as those described in the description of the non-dispersed undercoat layer can be used.

  Although it does not specifically limit as a specific coupling agent, For example, vinyl trimethoxysilane, (gamma) -methacryloxypropyl-tris ((beta) -methoxyethoxy) silane, (beta)-(3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, vinyltriacetoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, N- Examples include silane coupling agents such as β- (aminoethyl) -γ-aminopropylmethylmethoxysilane, N, N-bis (β-hydroxyethyl) -γ-aminopropyltriethoxysilane, and γ-chloropropyltrimethoxysilane. It is done. Moreover, these coupling agents can also be used in mixture of 2 or more types.

As the surface treatment method, any known method can be used, but a dry method or a wet method can be used. When surface treatment is performed by a dry method, while stirring metal oxide fine particles with a mixer having a large shearing force or the like, a coupling agent dissolved directly or in an organic solvent or water is added dropwise to dry air or nitrogen gas. It is processed uniformly by spraying together. The addition or spraying is preferably performed at a temperature of 50 ° C. or higher. After addition or spraying, baking can be performed at 100 ° C. or higher.
Baking can be carried out in an arbitrary range as long as the temperature and the time at which desired electrophotographic characteristics are obtained. In the dry method, the surface adsorbed water can be removed by heating and drying the metal oxide fine particles before the surface treatment with the coupling agent. By removing the surface adsorbed water before the treatment, the coupling agent can be uniformly adsorbed on the surface of the metal oxide fine particles.

  As a wet method, the metal oxide fine particles are stirred in a solvent, or dispersed using ultrasonic waves, a sand mill, an attritor, a ball mill, or the like. After further adding a coupling agent solution and stirring or dispersing, it is uniformly processed by removing the solvent. After removing the solvent, baking can be performed at 100 ° C. or higher. Baking can be carried out in an arbitrary range as long as the temperature and time allow the desired electrophotographic characteristics to be obtained. Even in the wet method, the surface adsorbed water can be removed before the surface treatment of the metal oxide fine particles with the coupling agent. As the surface adsorbed water removal method, in addition to heat drying similar to the dry method, a method of removing while stirring and heating in a solvent used for the surface treatment, a method of removing azeotropically with the solvent, and the like can be performed.

It is essential that the amount of the surface treatment agent with respect to the metal oxide fine particles is an amount capable of obtaining desired electrophotographic characteristics.
The electrophotographic characteristics are affected by the amount attached to the metal oxide fine particles after the surface treatment. In the case of a silane coupling agent, the amount attached is determined by the Si intensity in the fluorescent X-ray analysis and the main metal element of the metal oxide. Calculated from strength. The preferable Si intensity in the fluorescent X-ray analysis is in the range of 1.0 × 10 ⁻⁵ or more and 1.0 × 10 ⁻³ or less of the main metal element strength of the metal oxide. When the value falls below this range, image quality defects such as fogging tend to occur, and when the value exceeds this range, the density tends to decrease due to an increase in residual potential.

  Examples of the binder resin for the dispersion type undercoat layer include acetal resins such as polyvinyl butyral, polyvinyl alcohol resin, casein, polyamide resin, cellulose resin, gelatin, polyurethane resin, polyester resin, methacrylic resin, acrylic resin, and polyvinyl chloride. Examples thereof include known polymer resin compounds such as resin, polyvinyl acetate resin, vinyl chloride-vinyl acetate-maleic anhydride resin, silicone resin, silicone-alkyd resin, phenol resin, phenol-formaldehyde resin, melamine resin, and urethane resin. In addition, a charge transporting resin having a charge transporting group, a conductive resin such as polyaniline, or the like can be used. Among these, resins that are insoluble in the upper coating solvent are preferably used, and phenol resins, phenol-formaldehyde resins, melamine resins, urethane resins, epoxy resins, and the like are particularly preferably used.

  The undercoat layer 114 is formed by applying an undercoat layer forming coating solution in which the above-described constituent materials are dissolved and / or dispersed in a solvent onto the conductive support 112. When forming the dispersion-type undercoat layer, the ratio of the metal oxide fine particles to the binder resin in the dispersion-type undercoat layer-forming coating solution is arbitrary as long as desired electrophotographic photoreceptor characteristics can be obtained. Can be set.

As the solvent used for the coating solution for forming the undercoat layer, a known organic solvent can be used. For example, aromatic hydrocarbon solvents such as toluene and chlorobenzene, aliphatic alcohol solvents such as methanol, ethanol, n-propanol, iso-propanol and n-butanol, ketone solvents such as acetone, cyclohexanone and 2-butanone, Halogenated aliphatic hydrocarbon solvents such as methylene chloride, chloroform and ethylene chloride, cyclic or linear ether solvents such as tetrahydrofuran, dioxane, ethylene glycol and diethyl ether, esters such as methyl acetate, ethyl acetate and n-butyl acetate System solvents. These solvents can be used alone or in combination of two or more.
In addition, when mixing 2 or more types, any solvent can be used as long as it can dissolve the binder resin as a mixed solvent.

  Various additives can be used in the coating liquid for forming the undercoat layer in order to improve electrical characteristics, environmental stability, and image quality. Additives include quinone compounds such as chloranil, bromoanil and anthraquinone, tetracyanoquinodimethane compounds, fluorenones such as 2,4,7-trinitrofluorenone and 2,4,5,7-tetranitro-9-fluorenone Compounds, 2- (4-biphenyl) -5- (4-t-butylphenyl) -1,3,4-oxadiazole and 2,5-bis (4-naphthyl) -1,3,4-oxadi Azoles, oxadiazole compounds such as 2,5-bis (4-diethylaminophenyl) -1,3,4-oxadiazole, xanthone compounds, thiophene compounds, 3,3 ′, 5,5′-tetra- Electron transport materials such as diphenoquinone compounds such as t-butyldiphenoquinone, electron transport pigments such as polycyclic condensation systems and azo systems, zirconium chelate compounds, Hexafluorophosphate chelate compounds, aluminum chelate compounds, titanium alkoxide compounds, organic titanium compounds, there can be used a known material such as a silane coupling agent. The silane coupling agent is used for the surface treatment of the metal oxide fine particles, but it can also be added to the coating solution as an additive.

  Specific examples of the silane coupling agent used here may be the same as the specific examples of the coupling agent used for the surface treatment of the metal oxide fine particles. Examples of the zirconium chelate compound include zirconium butoxide, zirconium zirconium acetoacetate, zirconium triethanolamine, acetylacetonate zirconium butoxide, ethyl acetoacetate butoxide, zirconium acetate, zirconium oxalate, zirconium lactate, zirconium phosphonate, zirconium octoate, Zirconium naphthenate, zirconium laurate, zirconium stearate, zirconium isostearate, methacrylate zirconium butoxide, stearate zirconium butoxide, isostearate zirconium butoxide and the like.

  Examples of titanium chelate compounds include tetraisopropyl titanate, tetranormal butyl titanate, butyl titanate dimer, tetra (2-ethylhexyl) titanate, titanium acetylacetonate, polytitanium acetylacetonate, titanium octylene glycolate, titanium lactate ammonium salt. , Titanium lactate, titanium lactate ethyl ester, titanium triethanolamate, polyhydroxy titanium stearate and the like.

  Examples of the aluminum chelate compound include aluminum isopropylate, monobutoxy aluminum diisopropylate, aluminum butyrate, diethyl acetoacetate aluminum diisopropylate, aluminum tris (ethyl acetoacetate) and the like. These compounds can be used alone or as a mixture or polycondensate of a plurality of compounds.

  As a method of dispersing the metal oxide fine particles in the coating solution, a media dispersion machine such as a ball mill, a vibrating ball mill, an attritor, a sand mill, a horizontal sand mill, a medialess dispersion such as a stirring, an ultrasonic dispersion machine, a roll mill, a high-pressure homogenizer, etc. A machine is available. Furthermore, examples of the high-pressure homogenizer include a collision method in which the dispersion liquid is dispersed by liquid-liquid collision or liquid-wall collision in a high-pressure state, and a penetration method in which a fine flow path is dispersed in a high-pressure state.

As a coating method for forming the undercoat layer 114, a usual method such as a dip coating method, a ring coating method, a wire bar coating method, a spray coating method, a blade coating method, a knife coating method, or a curtain coating method is used. Can do.
The thickness of the undercoat layer 114 is preferably 0.1 μm or more and 3 μm or less. In addition to improving the wettability of the upper layer, the undercoat layer 114 also serves as an electrical blocking layer. However, when the film thickness exceeds 3 μm, the electrical barrier becomes too strong due to desensitization and repetition. It tends to cause an increase in potential.
Further, the film thickness of the dispersion type undercoat layer is preferably 3 μm or more, more preferably 5 μm or more and 30 μm or less. Furthermore, it is preferable that the dispersion type undercoat layer has a resin and filler structure that makes the Vickers strength 35 or more in order to improve leak resistance.
Further, the surface roughness of the undercoat layer has a roughness of about λ from ¼n times the exposure laser wavelength λ used (n is the refractive index of the upper layer) in order to prevent interference fringe images by the laser light source. It may be adjusted as follows. Resin particles can be added to the undercoat layer for adjusting the surface roughness. As the resin particles, silicone resin particles, cross-linked PMMA (polymethyl methacrylate) resin particles, and the like can be used. In addition, the undercoat layer can be polished to adjust the surface roughness. As a polishing method, buffing, sand blasting, wet honing, grinding, or the like can be used.

The charge generation layer 115 includes a charge generation material. The charge generation layer 115 is formed by vacuum deposition of a charge generation material or using a charge generation layer forming coating liquid containing a charge generation material and a binder resin.
Examples of the charge generation material used for the charge generation layer 115 include amorphous selenium, crystalline selenium, selenium-tellurium alloy, selenium-arsenic alloy, other selenium compounds and selenium alloys, amorphous silicon, cadmium sulfide and the like. Photoconductors and dye-sensitized photoconductors, various phthalocyanine pigments such as metal-free phthalocyanine, titanyl phthalocyanine, copper phthalocyanine, tin phthalocyanine, gallium phthalocyanine, naphthalocyanine pigment, squalium, anthanthrone, perylene, azo Various organic pigments and dyes such as trisazo, anthraquinone, pyrene, pyrylium salt and thiapyrylium salt are used.
In addition, these organic pigments generally have several crystal types, and in particular, phthalocyanine pigments are known in various crystal types including α type and β type. Note that any of these crystal types can be used as long as it is a pigment capable of obtaining sensitivity and other characteristics suitable for the purpose.

Among the charge generation materials described above, the following compounds are particularly suitable as charge generation materials that can provide excellent performance. Crystals having diffraction peaks at positions of at least 7.6 °, 10.0 °, 25.2 ° and 28.0 ° in the Bragg angle (2θ ± 0.2 °) of the X-ray diffraction spectrum using Cukα rays Hydroxygallium phthalocyanine represented by molds. A crystal having diffraction peaks at positions of at least 7.3 °, 16.5 °, 25.4 ° and 28.1 ° in the Bragg angle (2θ ± 0.2 °) of the X-ray diffraction spectrum using Cukα rays. Chlorgallium phthalocyanine represented by mold. Represented by crystal forms having diffraction peaks at positions of at least 9.5 °, 24.2 ° and 27.3 ° in the Bragg angle (2θ ± 0.2 °) of the X-ray diffraction spectrum using Cukα rays. Titanyl phthalocyanine.
Depending on the shape of the crystal and the measurement method, the positions of these peak intensities may slightly deviate from these values. However, if the X-ray diffraction patterns are basically the same, they are the same crystal type. It can be judged.

  Examples of the binder resin used for the charge generation layer 115 include polycarbonate resins such as bisphenol A type or bisphenol Z type and copolymers thereof, polyarylate resins, polyester resins, methacrylic resins, acrylic resins, and polyvinyl chloride resins. , Polystyrene resin, polyvinyl acetate resin, styrene-butadiene copolymer resin, vinylidene chloride-acrylonitrile copolymer resin, vinyl chloride-vinyl acetate-maleic anhydride resin, silicone resin, silicone-alkyd resin, phenol-formaldehyde resin, Examples thereof include styrene-alkyd resin and poly-N-vinylcarbazole. These binder resins can be used singly or in combination of two or more.

When the charge generation layer 115 is formed using a charge generation layer forming coating solution, the blending ratio (weight ratio) between the charge generation material and the binder resin is preferably in the range of 10: 1 to 1:10.
Examples of the method for dispersing the charge generating substance in the resin include a method using a roll mill, a ball mill, a vibrating ball mill, an attritor, a dyno mill, a sand mill, a colloid mill and the like.
The film thickness of the charge generation layer 115 is preferably 0.01 μm or more and 5 μm or less, and more preferably 0.05 μm or more and 2.0 μm or less.

The charge transport layer 116 includes a charge transport material and a binder resin.
Examples of the charge transport material used for the charge transport layer 116 include the following. Oxadiazole derivatives such as 2,5-bis (p-diethylaminophenyl) -1,3,4-oxadiazole, 1,3,5-triphenyl-pyrazoline, 1- [pyridyl- (2)]-3 -(P-diethylaminostyryl) -5- (p-diethylaminostyryl) pyrazoline and other pyrazoline derivatives, triphenylamine, tri (p-methyl) phenylamine, N, N-bis (3,4-dimethylphenyl) biphenyl- Aromatic tertiary amino compounds such as 4-amine, dibenzylaniline, 9,9-dimethyl-N, N-di (p-tolyl) fluorenon-2-amine, N, N′-diphenyl-N, N ′ Aromatic tertiary diamino compounds such as bis (3-methylphenyl)-[1,1-biphenyl] -4,4′-diamine, 3- (4′-dimethylaminophenyl)- 1,2,4-triazine derivatives such as 5,6-di- (4′-methoxyphenyl) -1,2,4-triazine, 4-diethylaminobenzaldehyde-1,1-diphenylhydrazone, 4-diphenylaminobenzaldehyde 1,1-diphenylhydrazone, [p- (diethylamino) phenyl] (1-naphthyl) phenylhydrazone, 1-pyrenediphenylhydrazone, 9-ethyl-3-[(2-methyl-1-indolinylimino) methyl] carbazole 4- (2-methyl-1-indolinyliminomethyl) triphenylamine, 9-methyl-3-carbazole diphenylhydrazone, 1,1-di- (4,4′-methoxyphenyl) acrylaldehyde diphenylhydrazone, β , Β-bis (methoxyphenyl) vinyldiphenylhydrazone, etc. Hydrazone derivatives, quinazoline derivatives such as 2-phenyl-4-styryl-quinazoline, benzofuran derivatives such as 6-hydroxy-2,3-di (p-methoxyphenyl) -benzofuran, p- (2,2-diphenylvinyl)- Hole transport materials such as α-stilbene derivatives such as N, N-diphenylaniline, enamine derivatives, carbazole derivatives such as N-ethylcarbazole, poly-N-vinylcarbazole and derivatives thereof.
Quinone compounds such as chloranil, bromoanil, anthraquinone, tetracyanoquinodimethane compounds, fluorenone compounds such as 2,4,7-trinitrofluorenone, 2,4,5,7-tetranitro-9-fluorenone, 2- ( 4-biphenyl) -5- (4-t-butylphenyl) -1,3,4-oxadiazole, 2,5-bis (4-naphthyl) -1,3,4-oxadiazole, 2,5 -Oxadiazole compounds such as bis (4-diethylaminophenyl) 1,3,4-oxadiazole, xanthone compounds, thiophene compounds, 3,3 ', 5,5'-tetra-t-butyldiphenoquinone Electron transport materials such as diphenoquinone compounds such as 3,5-dimethyl-3 ′, 5′-di-t-butyl-4,4′-diphenoquinone. Moreover, the polymer etc. which have the group induced | guided | derived from the compound shown above in the principal chain or a side chain are mentioned. These charge transport materials can be used alone or in combination of two or more.

  In a multilayer photoreceptor, the charge polarity of the photoreceptor varies depending on the charge transport polarity of the charge transport material. When a hole transport material is used, the photoreceptor is used with negative charge, and when an electron transport material is used, it is used with positive charge. When both are mixed, a photoconductor having both charged polarities is possible. Any binder resin can be used for the charge transport layer 16, but it is particularly desirable that the binder resin is compatible with the charge transport material and has an appropriate strength.

  Examples of the binder resin include various polycarbonate resins and copolymers thereof, such as bisphenol A, bisphenol Z, bisphenol C, and bisphenol TP, polyarylate resins and copolymers thereof, polyester resins, methacrylic resins, acrylic resins, Polyvinyl chloride resin, polyvinylidene chloride resin, polystyrene resin, polyvinyl acetate resin, styrene-butadiene copolymer resin, vinyl chloride-vinyl acetate copolymer resin, vinyl chloride-vinyl acetate-maleic anhydride copolymer resin, silicone Resin, silicone alkyd resin, phenol-formaldehyde resin, styrene-acrylic copolymer resin, ethylene-alkyd resin, poly-N-vinylcarbazole resin, polyvinyl butyral resin, polyphenylene ether resin, etc. It is below. These resins can be used alone or as a mixture of two or more.

  The charge transport layer 116 is formed by applying a charge transport layer forming coating solution in which the above-described charge transport material, binder resin, and other constituent materials are dissolved in an appropriate solvent on the charge generation layer 115 and drying it. Can be formed. The blending ratio between the charge transport material and the polymer is preferably 10: 1 to 1: 5.

Examples of the solvent used for forming the charge transport layer 116 include aromatic hydrocarbons such as benzene, toluene and chlorobenzene, ketones such as acetone and 2-butanone, and halogens such as methylene chloride, chloroform and ethylene chloride. Cycloaliphatic hydrocarbons, cyclic or linear ethers such as tetrahydrofuran, dioxane, ethylene glycol and diethyl ether, or a mixed solvent thereof can be used.
A small amount of silicone oil can be added to the coating solution as a leveling agent for improving the smoothness of the coating film.

When applying the charge transport layer forming coating solution, dip coating method, ring coating method, spray coating method, bead coating method, blade coating method, roller coating method, knife coating method, curtain coating method, etc. Can be used. Moreover, it is preferable that drying is heat-dried after finger-drying at room temperature. The heat drying is desirably performed at a temperature of 30 ° C. or more and 200 ° C. or less for 5 minutes or more and 2 hours or less.
The thickness of the charge transport layer 116 is preferably 5 μm to 50 μm, and more preferably 10 μm to 40 μm.

Further, additives such as an antioxidant, a light stabilizer, and a heat stabilizer are added to the photosensitive layer 13 for the purpose of preventing deterioration of the photoreceptor due to ozone, oxidizing gas, or light / heat generated in the image forming apparatus. It is preferable to contain.
Examples of the antioxidant include hindered phenol, hindered amine, paraphenylenediamine, arylalkane, hydroquinone, spirochroman, spiroidanone and derivatives thereof, organic sulfur compounds, and organic phosphorus compounds.
More specifically, antioxidants include 2,6-di-t-butyl-4-methylphenol, styrenated phenol, n-octadecyl-3- (3 ′, 5′-) as phenolic antioxidants. Di-t-butyl-4'-hydroxyphenyl) -propionate, 2,2'-methylene-bis- (4-methyl-6-t-butylphenol), 2-t-butyl-6- (3'-t- Butyl-5'-methyl-2'-hydroxybenzyl) -4-methylphenyl acrylate, 4,4'-butylidene-bis- (3-methyl-6-tert-butyl-phenol), 4,4'-thio- Bis- (3-methyl-6-tert-butylphenol), 1,3,5-tris (4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl) isocyanurate, tetrakis- [methylene-3- ( 3 ', 5 '-Di-t-butyl-4'-hydroxy-phenyl) propionate] -methane, 3,9-bis [2- [3- (3-t-butyl-4-hydroxy-5-methylphenyl) propionyloxy] -1,1-dimethylethyl] -2,4,8,10-tetraoxaspiro [5,5] undecane, 3-3 ′, 5′-di-tert-butyl-4′-hydroxyphenyl) stearyl propionate Etc.
Examples of hindered amine antioxidants include bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, 1- [ 2- [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionyloxy] ethyl] -4- [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionyloxy ] -2,2,6,6-tetramethylpiperidine, 8-benzyl-7,7,9,9-tetramethyl-3-octyl-1,3,8-triazaspiro [4,5] undecane-2,4 -Dione, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine, dimethyl-1- (2-hydroxyethyl) -4-hydroxy-2,2,6,6-tetramethylpi-succinate Lysine polycondensate, poly [{6- (1,1,3,3-tetramethylbutyl) imino-1,3,5-triazine-2,4-diimyl} {(2,2,6,6-tetra Methyl-4-piperidyl) imino} hexamethylene {(2,3,6,6-tetramethyl-4-piperidyl) imino}], 2- (3,5-di-t-butyl-4-hydroxybenzyl)- 2-n-butylmalonate bis (1,2,2,6,6-pentamethyl-4-piperidyl), N, N′-bis (3-aminopropyl) ethylenediamine-2,4-bis [N-butyl- N- (1,2,2,6,6, -pentamethyl-4-piperidyl) amino] -6-chloro-1,3,5-triazine condensate and the like.

Examples of organic sulfur-based antioxidants include dilauryl-3,3′-thiodipropionate, dimyristyl-3,3′-thiodipropionate, distearyl-3,3′-thiodipropionate, pentaerythritol-tetrakis. -(Β-lauryl-thiopropionate), ditridecyl-3,3′-thiodipropionate, 2-mercaptobenzimidazole and the like. Examples of the organophosphorus antioxidant include trisnonylphenyl phosfte, triphenyl phosfte, tris (2,4-di-t-butylphenyl) -phosfte, and the like.
The organic sulfur-based and organic phosphorus-based antioxidants are referred to as secondary antioxidants, and a synergistic effect can be obtained by using them together with a primary antioxidant such as a phenol-based or amine-based antioxidant.

Examples of the light stabilizer include benzophenone-based, benzotriazole-based, dithiocarbamate-based, and tetramethylpiperidine-based light stabilizers.
Examples of the benzophenone light stabilizer include 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, 2,2′-di-hydroxy-4-methoxybenzophenone, and the like.
Examples of the benzotriazole light stabilizer include 2- (2′-hydroxy-5′-methylphenyl) -benzotriazole, 2- [2′-hydroxy-3 ′-(3 ″, 4 ″, 5 ″). , 6 ″ -tetrahydrophthalimido-methyl) -5′-methylphenyl] -benzotriazole, 2-(-2′-hydroxy-3′-tert-butyl-5′-methylphenyl-)-5-chlorobenzotriazole 2- (2′-hydroxy-3′-t-butyl-5′-methylphenyl-)-5-chlorobenzotriazole, 2- (2′-hydroxy-3 ′, 5′-t-butylphenyl-) -Benzotriazole, 2- (2'-hydroxy-5'-t-octylphenyl) -benzotriazole, 2- (2'-hydroxy-3 ', 5'-di-t-amylphenyl) -benzotriazole and the like Can be mentioned. Examples of other compounds include 2,4, di-t-butylphenyl-3 ′, 5′-di-t-butyl-4′-hydroxybenzoate, nickel dibutyl-dithiocarbamate, and the like.

In addition, at least one electron accepting substance can be contained for the purpose of improving sensitivity, reducing residual potential, reducing fatigue during repeated use, and the like. Usable electron accepting substances include, for example, succinic anhydride, maleic anhydride, dibromomaleic anhydride, phthalic anhydride, tetrabromophthalic anhydride, tetracyanoethylene, tetracyanoquinodimethane, o-dinitrobenzene, m -Dinitrobenzene, crawranyl, dinitroanthraquinone, trinitrofluorenone, picric acid, o-nitrobenzoic acid, p-nitrobenzoic acid, phthalic acid and the like. Of these, fluorenone-based, quinone-based, and benzene derivatives having an electron-withdrawing substituent such as Cl, CN, NO ₂ are particularly preferable.

Examples of the form of the protective layer 117 include an insulating resin layer, a resistance control type protective layer in which a resistance control agent such as a metal oxide is dispersed, a charge transporting protective layer made of a polymer compound imparted with charge transporting properties, and the like. . The protective layer 117 improves the wear resistance of the photosensitive member to improve the life of the photosensitive member, improves matching with the developer, and changes the chemical change of the charge transport layer 116 when the electrophotographic photosensitive member is charged. It has functions such as prevention. Further, the protective layer 117 can realize an increase in the speed and life of the image forming apparatus.
In the present invention, among these, the photoreceptor 110 preferably has a charge transporting protective layer, and in particular, the charge transporting protective layer preferably contains a siloxane resin such as polysilane.

Hereinafter, the resistance control type protective layer will be described. As the resistance control agent (resistance control particles), carbon black, metal, metal oxide, or the like can be used. Examples of the metal oxide include titanium oxide, zinc oxide, tin oxide, antimony oxide-coated tin oxide, silicon oxide, iron oxide, aluminum oxide, cerium oxide, yttrium oxide, silicon oxide, zirconium oxide, iron oxide, magnesium oxide, Copper oxide, manganese oxide, molybdenum oxide, tungsten oxide, solid solution of barium sulfate and antimony oxide, mixture of the above metal oxides, the above metal oxides in a single particle of titanium oxide, tin oxide, zinc oxide or barium sulfate Or a mixture of the above metal oxides in single particles of titanium oxide, tin oxide, zinc oxide or barium sulfate.
Further, metallocene compounds such as N, N′-dimethylferrocene, N, N′-diphenyl-N, N′-bis (3-methylphenyl)-[1,1′-biphenyl] -4,4′-diamine, etc. Aromatic amine compounds and the like can also be used as resistance control agents.
These metal oxides can be surface treated with an organic compound such as a silane coupling agent, a titanium coupling agent, or a zirconium coupling agent to improve various properties such as dispersibility, if necessary. .

  Such resistance control agents include acetal resins such as polyvinyl butyral, polyvinyl alcohol resin, casein, polyamide resin, cellulose resin, gelatin, polyurethane resin, polyester resin, methacrylic resin, acrylic resin, polyvinyl chloride resin, polyvinyl acetate resin, vinyl chloride. -Vinyl acetate-maleic anhydride resin, silicone resin, silicone-alkyd resin, phenol resin, phenol-formaldehyde resin, melamine resin, epoxy resin, polyketone resin, polycarbonate resin, polyvinyl ketone resin, polystyrene resin, polyacrylamide resin, polyimide resin The film is dispersed in a polymer resin compound (binder resin) such as polyamideimide resin.

In addition, although a pigment is disperse | distributed to binder resin and formed into a film, in order to obtain appropriate coating-film resistance, the addition amount of a pigment is adjusted. The amount of pigment added is preferably 10% by volume to 60% by volume, more preferably 20% by volume to 50% by volume in the solid content.
It is more effective to use a resin having a certain degree of hardness in order to prevent the conductive foreign matter penetrating into the photoreceptor from the outside with the protective layer 117.

  Since the resistance control type protective layer uses a metal oxide having a particle size of 100 nm or less, the resistance control type protective layer is rich in transparency. Therefore, in addition to the high wear resistance strength, it also has the effect of increasing the film thickness, and the life of the photoreceptor can be further improved.

  Next, the charge transporting protective layer will be described. Such a protective layer can be formed of a charge transporting polymer compound. Examples of the charge transporting polymer compound include a polymer compound having a side chain containing a group having a charge transporting ability such as polyvinylcarbazole, and a charge transporting ability disclosed in JP-A-5-232727. Examples thereof include a polymer compound containing a group in the main chain, polysilane, and the like. Such a protective layer also functions as a charge transport layer.

  Moreover, a block copolymer or a graft copolymer comprising a charge transporting block and an insulating block can also be used as the charge transporting polymer compound. When the charge transporting polymer compound contains a triarylamine structure as a repeating unit, it is preferable because it has a high charge transporting ability and favorable mechanical properties, and the triarylamine structure is not a pendant type, More preferably, it is contained in the main chain. In the case of the pendant type, pendants are often associated with each other to form charge traps and deteriorate the charge transport property, but such problems can be avoided by being contained in the main chain.

  The charge transporting protective layer containing the charge transporting polymer compound described above is formed using the coating liquid for forming a charge transporting protective layer containing the constituent materials described above. Examples of coating methods for forming the protective layer include blade coating method, wire bar coating method, spray coating method, dip coating method, ring coating method, bead coating method, air knife coating method, curtain coating method, etc. The usual method can be used.

  Moreover, as a solvent used for the coating liquid for forming a protective layer, normal organic solvents, such as a dioxane, tetrahydrofuran, a methylene chloride, chloroform, chlorobenzene, toluene, alcohol, can be used individually or in mixture of 2 or more types. However, it is preferable to use a solvent that hardly dissolves the photosensitive layer to which the coating solution is applied.

  The thickness of the charge transporting protective layer is preferably 0.1 μm or more and 20 μm or less, more preferably 1 μm or more and 10 μm or less.

  A siloxane-based resin (polysilicon) may be used alone, or for the purpose of adjusting the film formability and flexibility of the film, the most preferred compounds described above, other coupling agents, fluorine compounds and You may mix and use. As such a compound, various silane coupling agents and commercially available silicon-based hard coat agents can be used.

  As silane coupling agents, vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxy Silane, γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropylmethyldimethoxysilane, N-β- (aminoethyl) -γ-aminopropyltriethoxysilane, tetramethoxysilane, methyltrimethoxy Silane, dimethyldimethoxysilane, or the like can be used. Commercially available hard coat agents include KP-85, X-40-9740, X-40-2239 (manufactured by Shin-Etsu Silicone), and AY42-440, AY42-441, AY49-208 (manufactured by Toray Dow Corning). Etc.) can be used.

  In order to impart water repellency and the like, (tridecafluoro-1,1,2,2-tetrahydrooctyl) triethoxysilane, (3,3,3-trifluoropropyl) trimethoxysilane, 3- (hepta) Fluoroisopropoxy) propyltriethoxysilane, 1H, 1H, 2H, 2H-perfluoroalkyltriethoxysilane, 1H, 1H, 2H, 2H-perfluorodecyltriethoxysilane, 1H, 1H, 2H, 2H-perfluorooctyl Fluorine-containing compounds such as triethoxysilane may be added. The silane coupling agent can be used in any amount, but the amount of the fluorine-containing compound is preferably 0.25% or less by weight with respect to the compound not containing fluorine. Beyond this, there may be a problem with the film formability of the crosslinked film.

  Preparation of the protective layer-forming coating solution (coating solution) for the protective layer described above is carried out in the absence of a solvent or, if necessary, alcohols such as methanol, ethanol, propanol and butanol; ketones such as acetone and methyl ethyl ketone; tetrahydrofuran , Ethers such as diethyl ether and dioxane can be used, but preferably have a boiling point of 100 ° C. or less, and can be used by arbitrarily mixing them. The amount of the solvent can be arbitrarily set, but if it is too small, the photofunctional organosilicon compound is likely to be precipitated. Therefore, it is preferably 0.5 parts by weight or more and 30 parts by weight or less with respect to 1 part by weight of the photofunctional organosilicon compound. More preferably, it is used in an amount of 1 to 20 parts by weight.

  The reaction temperature and time vary depending on the type of raw material, but it is usually preferably 0 to 100 ° C., preferably 10 to 70 ° C., particularly preferably 15 to 50 ° C. Although there is no restriction | limiting in particular in reaction time, Since it will become easy to produce gelation when reaction time becomes long, it is preferable to carry out in 10 minutes to 100 hours.

Here, the solid catalyst insoluble in the system is particularly if the catalyst component is insoluble in any of the above-mentioned compounds, other coupling agents, fluorine-containing compounds, water, reaction products and solvents. It is not limited. Specific examples of such a solid catalyst are illustrated below.
Cation exchange resin: Amberlite 15, Amberlite 200C, Amberlist 15 (above, manufactured by Rohm and Haas); Dowex MWC-1-H, Dowex 88, Dowex HCR-W2 (above, Dow Chemical Company); Lebatit SPC-108, Lebatit SPC-118 (above, Bayer); Diaion RCP-150H (Mitsubishi Kasei); Sumikaion KC-470, Duolite C26-C, Duolite C-433 Duolite-464 (manufactured by Sumitomo Chemical Co., Ltd.); Nafion-H (manufactured by DuPont) and the like.
Anion exchange resin: Amberlite IRA-400, Amberlite IRA-45 (above, manufactured by Rohm and Haas) and the like.
Inorganic solid in which a group containing a proton acid group is bonded to the surface: Zr (O ₃ PCH ₂ CH ₂ SO ₃ H) ₂ , Th (O ₃ PCH ₂ CH ₂ COOH) _2, etc.
Polyorganosiloxane containing a protonic acid group: polyorganosiloxane having a sulfonic acid group.
Heteropoly acid: cobalt tungstic acid, phosphomolybdic acid, etc.
Isopolyacid: niobic acid, tantalum acid, molybdic acid, etc.
Unitary metal oxides: silica gel, alumina, chromia, zirconia, CaO, MgO and the like.
Composite metal oxides: silica-alumina, silica-magnesia, silica-zirconia, zeolites and the like.
Clay minerals: acid clay, activated clay, montmorillonite, kaolinite, etc.
Metal sulfate: LiSO ₄ , MgSO _{4 and the} like.
Metal phosphate: zirconia phosphate, lanthanum phosphate, etc.
Metal nitrate: LiNO ₃ , Mn (NO ₃ ) ₂ etc.
Inorganic solid in which an amino group-containing group is bonded to the surface: a solid obtained by reacting aminopropyltriethoxysilane on silica gel.
Polyorganosiloxane containing amino groups: amino-modified silicone resin and the like.

  Of these catalysts, at least one kind is used to cause the hydrolysis condensation reaction. These catalysts can be installed in a fixed bed and the reaction can be carried out in a flow system or batchwise. Although the usage-amount of a catalyst is not specifically limited, 0.1 to 20 weight% is preferable with respect to the total amount of the material containing a hydrolyzable silicon substituent.

  The amount of water added during the hydrolytic condensation is not particularly limited. However, since it affects the storage stability of the product and the suppression of gelation when subjected to polymerization, it is preferable that the material containing a hydrolyzable silicon substituent is used. It is preferably used in a proportion of 30 mol% or more and 500 mol% or less, more preferably 50 mol% or more and 300 mol% or less, based on the theoretical amount required to hydrolyze all the hydrolyzable groups. When the amount of water is 500 mol% or less, the storage stability of the product is good, and the photofunctional organosilicon compound is difficult to precipitate, which is preferable. On the other hand, when the amount of water is 30 mol% or more, it is preferable because there are few unreacted compounds and phase separation does not occur during coating and curing. Moreover, since favorable intensity | strength can be obtained, it is preferable.

  Further, examples of the curing catalyst include the following. Protic acids such as hydrochloric acid, acetic acid, phosphoric acid and sulfuric acid, bases such as ammonia and triethylamine, organotin compounds such as dibutyltin diacetate, dibutyltin dioctoate and stannous oxalate, tetra-n-butyl titanate, tetraisopropyl titanate Organic titanium compounds such as aluminum tributoxide, aluminum triacetylacetonate, etc., organic carboxylic acid iron salts, manganese salts, cobalt salts, zinc salts, zirconium salts and the like. In terms of storage stability, a metal compound is preferable, and metal acetylacetonate or acetylacetate is more preferable.

  The amount of the curing catalyst used can be arbitrarily set, but it is 0.1% by weight or more and 20% by weight or less with respect to the total amount of materials containing hydrolyzable silicon substituents in terms of storage stability, characteristics, strength, and the like. Preferably, 0.3% by weight or more and 10% by weight or less is more preferable. The curing temperature can be arbitrarily set, but is preferably 60 ° C. or higher, and more preferably 80 ° C. or higher in order to obtain a desired strength.

  Although hardening time can be arbitrarily set as needed, 10 minutes or more and 5 hours or less are preferable. It is also effective to stabilize the characteristics after the curing reaction by maintaining a high humidity state. Furthermore, depending on the application, it can be hydrophobized by surface treatment with hexamethyldisilazane, trimethylchlorosilane, or the like.

  As a coating method, a normal method such as a blade coating method, a Meyer bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method, or a curtain coating method can be used. The film thickness is preferably about 0.1 μm to 100 μm.

Hereinafter, the single-layer type photosensitive layer 118 shown in FIG. 8 will be described. The single-layer type photosensitive layer 118 includes a charge generation material, a charge transport material, and a binder resin.
Examples of charge generating materials include amorphous selenium, crystalline selenium, selenium-tellurium alloy, selenium-arsenic alloy, other selenium compounds and selenium alloys, amorphous silicon, cadmium sulfide and other inorganic photoconductors, and dye-sensitized materials Sensitive, various phthalocyanine pigments such as metal-free phthalocyanine, titanyl phthalocyanine, copper phthalocyanine, tin phthalocyanine, gallium phthalocyanine, naphthalocyanine pigment, squalium, anthrone, perylene, azo, trisazo, anthraquinone, pyrene Various organic pigments and dyes, such as those based on the color, pyrylium salt and thiapyrylium salt, are used. In addition, these organic pigments generally have several types of crystals. In particular, phthalocyanine pigments have various crystal types including α type, β type, etc. Any of these crystal forms can be used as long as it is a pigment capable of obtaining characteristics.

Here, the following compounds are particularly suitable as the charge generating material that can provide excellent performance. Crystals having diffraction peaks at positions of at least 7.6 °, 10.0 °, 25.2 ° and 28.0 ° in the Bragg angle (2θ ± 0.2 °) of the X-ray diffraction spectrum using Cukα rays Hydroxygallium phthalocyanine represented by molds. A crystal having diffraction peaks at positions of at least 7.3 °, 16.5 °, 25.4 °, and 28.1 ° in the Bragg angle (2θ ± 0.2 °) of the X-ray diffraction spectrum using Cukα rays. Chlorgallium phthalocyanine represented by mold. Represented by crystal types having diffraction peaks at positions of at least 9.5 °, 24.2 °, and 27.3 ° in the Bragg angle (2θ ± 0.2 °) of the X-ray diffraction spectrum using Cukα rays. Titanyl phthalocyanine.
Depending on the crystal shape and measurement method, these peak intensities may slightly deviate from these values. However, if the X-ray diffraction patterns are basically the same, they are the same crystal type. It can be judged.
The charge generating materials exemplified above can be used alone or in combination of two or more so as to have an absorption wavelength in a desired region in accordance with the spectrum of the light source.

  Among the charge generating materials exemplified above, in particular, a laser beam printer using a light source such as a semiconductor laser or an image forming apparatus of a digital optical system such as a facsimile requires a photosensitive member having sensitivity in a wavelength region of 700 nm or more. Therefore, phthalosinine pigments such as gallium phthalocyanine and oxytitanium phthalocyanine are preferably used. For a blue laser having an oscillation wavelength in the blue region of 400 nm or more and 500 nm or less, the Se pigment is preferably an azo pigment or an aromatic polycyclic compound.

  Examples of the charge transport material include conventionally known electron transport materials and hole transport materials. In the single-layer type photosensitive layer, it is preferable to blend and contain an electron transport material and a hole transport material in the photosensitive layer, but there are cases where an electron transport material is not used.

  Electron transport materials that can be used for the single-layer photosensitive layer 118 include diphenoquinone derivatives, benzoquinone derivatives, anthraquinone derivatives, malononitrile derivatives, thiopyran derivatives, trinitrothioxanthone derivatives, 3,4,5,7-tetranitro-9-. Fluorenone derivative, dinitroanthracene derivative, dinitroacridine derivative, nitroantharaquinone derivative, dinitroanthraquinone derivative, tetracyanoethylene, 2,4,8-trinitrothioxanthone, dinitrobenzene, dinitroanthracene, dinitroacridine, nitroanthraquinone, dinitroanthraquinone, Examples include various compounds having electron accepting properties such as succinic anhydride, maleic anhydride, and dibromomaleic anhydride. In particular, quinone derivatives such as 3,3 ′, 5,5′-tetra-t-butyldiphenoquinone and 3,5-dimethyl-3 ′, 5′-di-t-butyl-4,4′-diphenoquinone are used. Preferably used.

Only one type of electron transport material may be used, or two or more types may be blended. Examples of the hole transporting agent that can be used for the electrophotographic photosensitive member include N, N, N ′, N′-tetraphenylbenzidine derivatives, N, N, N ′, N′-tetraphenylphenylenediamine derivatives, N, N, N ′, N′-tetraphenylnaphthylenediamine derivative, N, N, N ′, N′-tetraphenylphenanthrylenediamine derivative, 2,5-di (4-methylaminophenyl) -1,3,4 Oxadiazole compounds such as oxadiazole, styryl compounds such as 9- (4-diethylaminostyryl) anthracene, carbazole compounds such as polyvinylcarbazole, organic polysilane compounds, 1-phenyl-3- (p-dimethylaminophenyl) ) Pyrazoline compounds such as pyrazoline, hydrazone compounds, indole compounds, oxazole compounds, iso Kisazoru compounds, thiazole compounds, thiadiazole compounds, imidazole compounds, pyrazole compounds, and nitrogen-containing cyclic compounds such as triazole compounds, and condensed polycyclic compounds.
Further, not only one kind of hole transport material but also two or more kinds may be blended and used.

The binder resin includes various polycarbonate resins having skeletons of bisphenols such as bisphenol Z, bisphenol A, and bisphenol C, copolymers thereof, polyester resins, polyarylate resins, styrene-butadiene copolymers, styrene-acrylonitrile copolymers. Polymer, styrene-maleic acid copolymer, acrylic copolymer, styrene-acrylic acid copolymer, polyethylene, ethylene-vinyl acetate copolymer, chlorinated polyethylene, polyvinyl chloride, polypropylene, ionomer, vinyl chloride-vinyl acetate Copolymers, alkyd resins, polyamides, polyurethanes, polysulfones, diallyl phthalate resins, ketone resins, polyvinyl butyral resins, polyether resins and other thermoplastic resins, silicone resins, epoxy resins, phenol resins, urea Fat, melamine resins, and other crosslinkable thermosetting resin, epoxy acrylate, urethane - resin such as photocurable resin such as acrylate can be used.
In addition, these binder resins can be used singly or in a blend or copolymer of two or more. The weight average molecular weight of the above binder resin is preferably 5,000 or more and 200,000 or less, more preferably 15,000 or more and 100,000 or less.

In the single-layer type photosensitive layer 118, the charge generation material is preferably contained in an amount of 0.1% by weight to 50% by weight, and more preferably 0.5% by weight to 30% by weight, based on the total weight of the binder resin. The electron transfer agent is preferably contained in an amount of 5% by weight to 100% by weight, more preferably 10% by weight to 80% by weight, based on the total weight of the binder resin. The hole transport material is preferably contained in an amount of 5% by weight or more and 500% by weight or less, and more preferably 25% by weight or more and 200% by weight or less based on the total weight of the binder resin. When the electron transport material and the hole transport material are used in a blend, the total amount of the electron transport material and the hole transport material is preferably 20% by weight or more and 500% by weight or less based on the total binder resin. More preferably, the content is 30% by weight or more and 200% by weight or less.
The film thickness of the single-layer type photosensitive layer 118 is preferably 5 μm or more and 100 μm or less, more preferably 10 μm or more and 50 μm or less.

  In the photosensitive layer 113, in addition to the above-described components, various conventionally known additives, for example, an antioxidant, a radical scavenger, a singlet quencher, and an ultraviolet absorption, as long as the electrophotographic characteristics are not adversely affected. Deterioration preventing agents such as agents, softeners, plasticizers, surface modifiers, extenders, thickeners, dispersion stabilizers, waxes, acceptors, donors, and the like can be blended. In order to improve the sensitivity of the photosensitive layer, for example, a known sensitizer such as terphenyl, halonaphthoquinones, acenaphthylene and the like may be used in combination with the charge generating substance.

  When the photosensitive layer 113 is formed by a coating method, the charge generating material, charge transporting material, binder resin, and the like exemplified above are combined with a suitable solvent together with a known method such as a roll mill, a ball mill, an attritor, a paint shaker. Then, a dispersion liquid may be prepared by dispersion blending using an ultrasonic disperser or the like, and this may be applied and dried by a known means.

As the solvent for preparing the dispersion, various organic solvents can be used, for example, alcohols such as methanol, ethanol, isopropanol and butanol, and aliphatic hydrocarbons such as n-hexane, octane and cyclohexane. , Aromatic hydrocarbons such as benzene, toluene, xylene, halogenated hydrocarbons such as dichloromethane, dichloroethane, chloroform, carbon tetrachloride, chlorobenzene, ethers such as dimethyl ether, diethyl ether, tetrahydrofuran, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, Ketones such as acetone, methyl ethyl ketone and cyclohexanone, esters such as ethyl acetate and methyl acetate, dimethylformaldehyde, dimethylformamide, dimethyl sulfoxide And the like. These solvents are used alone or in combination of two or more.
Further, a surfactant, a leveling agent or the like may be used in order to improve the dispersibility of the charge generation material, the charge transport material and the like and the smoothness of the photosensitive layer surface.

  The photoconductor 110 thus obtained can also be used in image forming apparatuses such as light lens copying machines, laser beam printers that emit near-infrared light or visible light, digital copying machines, LED printers, and laser facsimiles. . The photoreceptor 110 can be used in combination with a one-component or two-component developer. The photoconductor 110 described above can also be used in a contact charging system using a charging roller or a charging brush.

The charging device 120 is not particularly limited, but a contact charger can be used. The contact-type charger is preferable in that it has excellent charge compensation capability.
In the contact charging method, the surface of the photoconductor 110 is charged by applying a voltage to a charging roll brought into contact with the surface of the photoconductor 110. Usually, the charging roll is composed of a resistance layer, an elastic layer that supports them, and a core material from the outside. Further, a protective layer may be provided outside the resistance layer as necessary.
In order to charge the photoreceptor 110 using these charging rolls 122, a voltage may be applied to the charging roll 122. The applied voltage is preferably a DC voltage or a DC voltage superimposed with an AC voltage. As the voltage range, the DC voltage is preferably positive or negative 50 V or more and 2,000 V or less, particularly preferably 100 V or more and 1,500 V or less, depending on the required photosensitive member charging potential. When the AC voltage is superimposed, the peak-to-peak voltage is preferably 400 V or more and 1,800 V or less, more preferably 800 V or more and 1,600 V or less, and further preferably 1,200 V or more and 1,600 V or less. The frequency of the AC voltage is preferably 50 Hz or more and 20,000 Hz or less, and more preferably 100 Hz or more and 5,000 Hz or less.

  The exposure apparatus 130 is not particularly limited, and examples thereof include optical equipment that can expose the surface of the photoreceptor 110 with light such as semiconductor laser light, LED light, and liquid crystal shutter light in a desired image manner. The wavelength of the light source is in the spectral sensitivity region of the photoreceptor. As the wavelength of the semiconductor laser, near infrared having an oscillation wavelength near 780 nm is the mainstream. However, the present invention is not limited to this wavelength, and an oscillation wavelength laser in the 600 nm range or a laser having an oscillation wavelength in the vicinity of 400 nm to 450 nm as a blue laser can be used. For color image formation, a surface-emitting laser light source capable of multi-beam output is also effective.

The developing device 140 can be performed using, for example, a general developing device that performs development by bringing a magnetic or non-magnetic one-component developer or two-component developer into contact or non-contact. Such a developing device is not particularly limited as long as it has the functions described above, and can be appropriately selected according to the purpose. For example, a known developing device having a function of attaching the one-component developer or the two-component developer to the photoreceptor 10 using a brush, a roll, or the like can be used.
In FIGS. 5 and 6, the toner transported from the toner storage unit 146 to the developer storage unit 145 by the toner supply member 144 is transported to the developer carrier by the developer agitation and transport members 142 and 143.

  In the developing device 140, various developers can be used. The spherical toner formed by the polymerization method has a spherical shape (preferred sphericity (shape factor): 100 or more and 135 or less) and has a very uniform particle size, so that the transfer efficiency to the transfer medium is high and clear. An image can be formed.

  In the image forming apparatus 100, even when spherical toner is used as the toner, the charging roll 122 can be suitably cleaned by providing the cleaning roll 123.

The transfer device 150 is not particularly limited. For example, a contact transfer charger using a belt, roll, film, rubber blade, etc., a scorotron transfer charger using a corona discharge, a corotron transfer charger, and the like are known per se. Examples include a transfer charger. Among these, a contact type transfer charger is preferable in that it has excellent transfer charge compensation capability. In the present embodiment, a peeling charger or the like can be used in combination with the transfer charger.
In addition, a direct current is normally used as a transfer current applied from the transfer device 150 to the photoconductor 110 during transfer, but in the present embodiment, an alternating current may be further superimposed. . The setting conditions in the transfer device 150 differ depending on the width of the image area to be charged, the shape of the transfer charger, the opening width, the process speed (peripheral speed), etc., and cannot be specified unconditionally. The set value can be +400 μA or less and the transfer voltage can be +500 V or more and +2,000 V or less.

  The fixing device 160 is not particularly limited, and a commonly used device such as a heat roll fixing device or an oven fixing device can be used. The toner image transferred onto the transfer medium can be fixed by the fixing device 160.

In addition to the above-described devices, the image forming apparatus 100 may include, for example, an optical static elimination device that performs optical static elimination on the photoconductor 110.
Examples of the light neutralization device include tungsten lamps and LEDs. Examples of the light quality used in the light neutralization process include white light such as tungsten lamps and red light such as LED light. The irradiation light intensity in the photostatic process is usually set so that it is several times to 30 times the amount of light showing the half exposure sensitivity of the electrophotographic photosensitive member. In addition, an optical static elimination process etc. can be implemented suitably by using said apparatus.

  Further, the image forming apparatus 100 may adopt an intermediate transfer method, and in this case, includes an intermediate transfer member, an intermediate transfer member cleaner for cleaning the intermediate transfer member, and the like.

  EXAMPLES Hereinafter, although this invention is demonstrated with reference to an Example, this invention is not limited to this.

(Example 1)
As the resin foam of the cleaning roll, 97 parts of RSM-50 manufactured by Inoac Corporation and 3 parts of Unidyne TG470B (fluorine resin) manufactured by Daikin Industries, Ltd. were used.
<Preparation and application of spray coating liquid>
A water-emulsion paint (Emulalon JYL-804 ESD: solid content 30% by weight) obtained by adding carbon black and fluororesin powder to acrylic modified urethane resin manufactured by Nippon Atchison Co., Ltd. was spray-coated. Then, it heated at 70 degreeC for 70 minutes, and formed the surface layer with a film thickness of 20 micrometers.

(Example 2)
<Production of resin foam>
A cleaning roll made of a resin foam was produced in the same manner as in Example 1 except that Unidyne TG470B (fluororesin) was not added. Thereafter, in the same manner as in Example 1, a water-emulsion paint containing a fluororesin was spray-coated and heated at 70 ° C. for 70 minutes to form a surface layer having a thickness of 20 μm.

(Example 3)
A roll was prepared in the same manner as in Example 1 except that n-decyltrimethoxysilane (AX43-045) manufactured by Toray Dow Corning Silicone was used instead of Unidyne TG470B. Thereafter, in the same manner as in Example 1, a water-emulsion paint containing a fluororesin was spray-coated and heated at 70 ° C. for 70 minutes to form a surface layer having a thickness of 20 μm.

(Comparative Example 1)
A cleaning roll was produced in the same manner as in Example 1 except that a water-emulsion paint without adding fluororesin particles was used.

(Image forming device)
The DocuPrint 205 process cartridge was remodeled, and a running test of 20,000 sheets was performed under high temperature and high humidity (28 ° C / 85% RH) and low temperature and low humidity (10 ° C / 15% RH) conditions. The presence or absence of local image quality defects (color points) was confirmed. Note that the number of color points generated was used as a criterion for evaluation. The criteria are as follows, and the worse results were used as the criteria.
A: Not generated with 20,000 sheets.
○: Occurs at 17,000 or more and less than 20,000.
Δ: Generated when the number is 15,000 or more and less than 17,000.
X: Occurs in less than 15,000 sheets.
The results are shown in the table below.

It is explanatory drawing which shows suitable one Embodiment of the cleaning apparatus of this invention. It is a perspective view which shows the 2nd roll of the cleaning apparatus shown by FIG. It is a schematic sectional drawing of the II-II line direction of the 2nd roll shown by FIG. It is a schematic sectional drawing which shows other embodiment of the 2nd roll which can be used for this invention. 1 is a schematic diagram illustrating a basic configuration of a preferred embodiment of an image forming apparatus of the present invention. 1 is a schematic diagram illustrating a basic configuration of a preferred embodiment of an image forming apparatus of the present invention. It is a schematic cross-sectional view showing a preferred example of a photoreceptor. It is a schematic cross-sectional view showing a preferred example of a photoreceptor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 3 Support part 4 Adhesion part 5 Contact part 10 Cleaning apparatus 12 Image holding body 14 1st roll 16 2nd roll 100 Image forming apparatus 110 Photosensitive body (image holding body)
112 conductive support 113 photosensitive layer 114 undercoat layer 115 charge generation layer 116 charge transport layer 117 protective layer 118 single layer type photosensitive layer 120 charging device 122 charging roll 123 cleaning roll 130 exposure device 135 laser exposure path 140 developing device 141 development Developer carrier 142 Developer agitation and conveyance member 143 Developer agitation and conveyance member 144 Toner supply member 145 Developer supply unit 146 Toner storage unit 150 Transfer device 160 Fixing device 170 Photoconductor cleaning device 171 Cleaning blade 172 Cleaned toner recovery unit 180 Transport roll 200 Process cartridge

Claims (6)

A first roll that can contact the image carrier;
A second roll that can contact the first roll;
The second roll has a resin foam on the outer periphery of the core, and
A cleaning device, wherein the surface of the resin foam contains a material having releasability.   The cleaning device according to claim 1, wherein the first roll is a contact charging roll.   The cleaning device according to claim 1, wherein the material having releasability is a resin containing fluorine.   The cleaning device according to claim 1, wherein the surface of the image carrier contains a siloxane-based resin. A process cartridge that includes at least an image carrier, a charging roll, and a cleaning unit that removes the developer attached to the surface of the charging roll, and is detachable from the image forming apparatus;
The process cartridge according to claim 1, wherein the cleaning unit is the cleaning device according to claim 1. At least an image carrier, a charging unit for charging the surface of the image carrier, an exposure unit for exposing the surface of the image carrier to form a latent image, and a developer carrying the latent image on the developer carrier. An image forming apparatus comprising: a developing unit that develops; a transfer unit that transfers a developed image to a transfer target; and a cleaning unit that removes residual toner on the charging member.
5. The image forming apparatus according to claim 1, wherein the cleaning unit is the cleaning apparatus according to claim 1.

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