JP2007178815A - Electrophotographic photoreceptor, process cartridge and electrophotographic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor which is hardly contaminated, so that uneven rotation of the photoreceptor particularly due to an external additive sticking on the photoreceptor is prevented through its lifetime, on which toner deterioration and fusion occur infrequently, and which has so good cleanability that it can stably provide high quality images over a prolonged period of time. <P>SOLUTION: The electrophotographic photoreceptor has a photosensitive layer on a support, wherein a surface layer of the photoreceptor contains a diorganopolysiloxane having a repeating structural unit α represented by the formula (1): (R<SB>1</SB>B<SB>1</SB>)SiO and a repeating structural unit β represented by the formula (2): (R<SB>2</SB>D<SB>1</SB>)SiO and having a weight average molecular weight of 1,000-1,000,000, wherein B<SB>1</SB>denotes a perfluoroalkyl group; D<SB>1</SB>denotes a carboxylic ester group; and R<SB>1</SB>and R<SB>2</SB>each denote a hydrocarbon group. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electrophotographic photosensitive member, a process cartridge, and an electrophotographic apparatus, and more specifically, an electrophotographic photosensitive member having a surface layer containing a specific diorganopolysiloxane, a process cartridge including the electrophotographic photosensitive member, and an electrophotographic apparatus. Relates to the device.

  Conventionally, various methods such as an electrophotographic method, a thermal transfer method, and an ink jet method are employed in an image forming apparatus. Among these, an image forming apparatus (electrophotographic apparatus) that employs an electrophotographic system has advantages in terms of high speed, high image quality, and quietness compared to an image forming apparatus that employs other systems. Yes.

  In addition to monochrome electrophotographic apparatuses, multi-color electrophotographic apparatuses (color electrophotographic apparatuses) have recently become widespread. There are various types of color electrophotographic apparatuses. For example, a single electrophotographic photosensitive member is sequentially exposed and developed for each color, and a toner image of each color is transferred to a transfer material holding member (transfer drum or the like). Multiple transfer system that forms a color image by sequentially transferring onto a material (paper, etc.). Also, exposure and development are sequentially performed one color at a time on one electrophotographic photosensitive member, and toner images of each color are sequentially primary transferred onto an intermediate transfer member (intermediate transfer drum, intermediate transfer belt, etc.), and then transferred onto a transfer material. Intermediate transfer system that forms a color image by performing secondary transfer in a batch. Further, each color toner image is formed in each color image forming unit (having an electrophotographic photosensitive member, an exposure unit, and a developing unit) arranged in series, and these are formed on a transfer material conveying member (such as a transfer material conveying belt). An in-line method for forming a color image by sequentially transferring images onto transfer materials that are sequentially conveyed to each image forming unit is well known.

  In addition, with the widespread use of color electrophotographic apparatuses, further improvement in image quality is required as a direction of electrophotographic technology. Conventional resolutions of 240 and 300 dpi have become high resolutions of 400, 600 and 1200 dpi. Accordingly, the development method is also required to have high definition. Copiers are also becoming more sophisticated, and are therefore moving toward digitalization. In digital machines, a method of forming an electrostatic latent image with a laser is the mainstream, and progressing in the direction of high resolution, and a high-resolution and high-definition developing method has been awaited as with a printer. For this reason, the toner particle size is also being reduced. For example, Patent Documents 1 to 6 propose a toner having a specific particle size distribution and a small particle size. In this case, the cleaning member is severely set from the viewpoint of cleaning properties, toner deterioration, electrophotographic photosensitive member surface contamination, and toner fusing are likely to occur. For this reason, measures such as increasing the amount of external additive added are often required.

  Under such circumstances, further releasability has been required for the electrophotographic photosensitive member. As means for improving the releasability, the surface layer of the electrophotographic photosensitive member can be separated by adding a silicone resin to the surface layer of the electrophotographic photosensitive member or dispersing fluorine atom-containing resin particles (fluorine resin powder). It is known to improve moldability.

  However, when a silicone resin is contained in the surface layer of the electrophotographic photosensitive member, the water repellency of the surface of the electrophotographic photosensitive member is improved to some extent, but it is not yet sufficient as the releasability required at the time of transfer. . Further, since the silicone resin easily migrates to the surface of the layer, even if the effect is obtained in the initial stage, if the surface of the electrophotographic photosensitive member is worn due to endurance use, the effective components are lost, and for a long time. The effect cannot be maintained.

  In that respect, when the fluorine atom-containing resin particles are dispersed in the surface layer of the electrophotographic photosensitive member, an improvement in the releasability of the surface of the electrophotographic photosensitive member can be expected compared to the case of using a silicone resin. Fluorine atom-containing resin particles include tetrafluoroethylene resin, trifluoroethylene chloride resin, tetrafluoroethylene hexafluoroethylenepropylene resin, vinyl fluoride resin, vinylidene fluoride resin, difluorodiethylene chloride resin, And particles, such as these copolymer resins, are mentioned (patent documents 7 and 8). In Patent Documents 7 and 8, the dispersibility of the fluorine atom-containing resin particles in the surface layer can be improved by containing a diorganopolysiloxane having a specific structure in the surface layer of the electrophotographic photosensitive member. Is disclosed.

  However, the fluorine atom-containing resin particles in the surface layer of the electrophotographic photosensitive member scatter the exposure light, so that it is difficult to obtain a sharp electrostatic latent image, and there are cases where image quality is restricted.

Maintaining high releasability on the surface of an electrophotographic photosensitive member over a long period of time and obtaining a sharp electrostatic latent image are required for all electrophotographic apparatuses. A color electrophotographic apparatus as described above that forms an image and superimposes them to form a single color image is required to have a higher dimension.
Japanese Patent Laid-Open No. 1-112253 JP-A-1-191156 JP-A-2-214156 JP-A-2-284158 Japanese Patent Laid-Open No. 3-181952 JP-A-4-162048 JP 2000-081715 A Japanese Patent Laid-Open No. 2001-249481

  The object of the present invention is to prevent the electrophotographic photosensitive member from being easily contaminated, and in particular, to prevent the occurrence of uneven rotation of the electrophotographic photosensitive member due to an external additive adhering to the electrophotographic photosensitive member throughout its life, and to prevent deterioration and melting of the toner. Another object of the present invention is to provide an electrophotographic photosensitive member that is less likely to adhere and that can provide sufficient cleaning properties without strengthening cleaning conditions and can stably provide high-quality images for a long period of time.

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

  According to the present invention, in the electrophotographic photosensitive member having a photosensitive layer on the support, the surface layer of the electrophotographic photosensitive member is a repeating structural unit α represented by the following formula (1) and a repeating represented by the following formula (2). An electrophotographic photoreceptor comprising a diorganopolysiloxane having a structural unit β and having a weight average molecular weight of 1,000 to 1,000,000 is provided.

In the above formulas (1) and (2), R ₁ and R ₂ each independently represent a substituted or unsubstituted monovalent hydrocarbon group, and B ₁ is a monovalent organic group having a perfluoroalkyl group. D ₁ represents a monovalent organic group containing a repeating unit represented by the following formula (11) or (21).

In the above formula (11), R ₁₁ and R ₁₂ represent a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group. n represents an integer of 3 or more.

In the above formula (21), R ₂₁ represents a single bond, a carbonyl group, an ether group, a thioether group or a —C (R ₃₄ ) (R ₃₅ ) — group (R ₃₄ and R ₃₅ are each independently a hydrogen atom, Or an unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted cycloalkylidene group formed by combining R ₃₄ and R ₃₅ ). R _{22 to} R ₂₉ each independently represent a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group. n represents an integer of 3 or more. X represents —CO— or the following formula (X1).

In the formula (X1), R _{30 to} R ₃₃ each independently represent a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group.

  In addition, according to the present invention, a process cartridge and an electrophotographic apparatus provided with the electrophotographic photosensitive member are provided.

  As described above, by using the electrophotographic photosensitive member of the present invention, it becomes difficult for excessive toner and contaminants to adhere to the surface of the electrophotographic photosensitive member, and toner deterioration and fusion hardly occur. Providing an electrophotographic photosensitive member that can stably provide a high-quality image for a long period of time while maintaining a clean cleaning state, and also prevent secondary image defects that occur with the progress of scratches and deterioration due to contamination It became possible to do.

  The surface layer of the electrophotographic photoreceptor of the present invention has a repeating structural unit α represented by the above formula (1) and a repeating structural unit β represented by the above formula (2), and has a weight average molecular weight of 1,000 to 1,000,000. Contains diorganopolysiloxane. As a result, the releasability of the surface of the electrophotographic photosensitive member can be greatly improved continuously, the adhesion of toner and external additives to the surface of the electrophotographic photosensitive member can be controlled, cleaning can be facilitated, and uneven rotation can be achieved. Can be suppressed.

  The diorganopolysiloxane may further have a repeating structural unit γ represented by the following formula (3).

In the above formula (3), R ₃ and R ₄ each independently represent a substituted or unsubstituted monovalent hydrocarbon group.

  Examples of the terminal group of the diorganopolysiloxane include a terminal group I having a structure represented by the following formula (4) and a terminal group II having a structure represented by the following formula (5).

In the above formulas (4) and (5), R ₅ and R ₆ each independently represent a substituted or unsubstituted monovalent hydrocarbon group, and E ₁ and E ₂ each independently represent a substituted or unsubstituted group. A substituted monovalent hydrocarbon group, a monovalent organic group having a perfluoroalkyl group, a monovalent organic group having a substituted or unsubstituted polystyrene chain having a polymerization degree of 3 or more, and a substituted or unsubstituted alkyleneoxy group. A monovalent organic group having, a monovalent organic group having a substituted or unsubstituted siloxane chain, and a monovalent group selected from the group consisting of monovalent organic groups having 12 or more carbon atoms, E ₁ in the formula (4) is bonded to Si in the main chain (-Si-O-) of the repeating structural unit of the diorganopolysiloxane, and Si in the formula (5) is the diorgano The main chain of repeating structural units possessed by polysiloxane (- i-O-) binds to the O in.

  In the present invention, the organic group means a substituted or unsubstituted hydrocarbon group. Examples of the hydrocarbon group include an alkyl group, an alkenyl group, an aryl group, and an arylalkenyl group.

Examples of the monovalent hydrocarbon group for R _{1 to} R ₆ include a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted arylalkenyl group, and the like. Can be mentioned. These groups preferably have 1 to 30 carbon atoms, and more preferably a methyl group and a phenyl group.

The monovalent organic group having a B ₁ perfluoroalkyl group is preferably a monovalent group having a structure represented by the following formula (31) or (32).

In the above formula (2) and (3), R ₄₁ and R ₄₂ represents an alkylene group or alkylene oxyalkylene group, a and b is an integer of 1 or more, c is 0 or an integer of 1 or more. Rf ₁ to ₃ represent a fluorine atom or a fluoroalkyl group. Examples of the fluoroalkyl group include CF ₃ , C ₂ F ₅ , C ₄ F ₉ and C ₈ F ₁₇ , and CF ₃ and C ₂ F ₅ are preferable.

  Examples of the alkylene group include an ethylene group and a propylene group. Examples of the alkyleneoxyalkylene group include an ethyleneoxyethylene group, an ethyleneoxypropylene group, and a propyleneoxypropylene group.

In the monovalent organic group having a repeating unit containing structure represented by the following formula (11) of D ₁ , R ₁₂ is a hydrogen atom or a methyl group as represented by the following formulas (12) to (13). It is preferable.

In the above formulas (11) to (13), R ₁₁ and R ₁₂ represent a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group. Further, the structure represented by the formula (11) may be one type or two or more types of copolymerization. In the case of copolymerization, each repeating unit is randomly arranged. N represents an integer of 3 or more.

  Below, the structural example of the structural unit (beta) which has a repeating unit shown by Formula (11) is shown.

In the monovalent organic group having a repeating unit containing structure represented by the following formula (21) of D ¹ , X in the formula is preferably the following formula (X-2) or —CO—.

In the above formula (21), R ₂₁ represents a single bond, a carbonyl group, an ether group, a thioether group or a —C (R ₃₄ ) (R ₃₅ ) — group (R ₃₄ and R ₃₅ are each independently a hydrogen atom, Or an unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted cycloalkylidene group formed by combining R ₃₄ and R ₃₅ ). R _{22 to} R ₂₉ each independently represent a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group. n represents an integer of 3 or more.

  Below, the structural example of the structural unit (beta) which has a repeating unit shown by Formula (21) is shown.

  The number (average) of repeating structural units α represented by the above formula (1) in the diorganopolysiloxane is preferably 1 to 1000, and more preferably 10 to 200.

  The number (average) of repeating structural units β represented by the above formula (2) in the diorganopolysiloxane is preferably 1 to 1000, and more preferably 5 to 100.

  The number (average) of repeating structural units γ represented by the above formula (3) in the diorganopolysiloxane is preferably 0 to 1000, more preferably 5 to 200.

  The repeating structural unit possessed by the diorganopolysiloxane is the repeating structural unit α represented by the above formula (1) and the repeating structural unit β represented by the above formula (2) or the repeating structural unit represented by the above formula (1). It is preferable that there are only the structural unit α, the repeating structural unit β represented by the above formula (2), and the repeating structural unit γ represented by the above formula (3).

  Sum (average) of the repeating structural unit α represented by the formula (1), the repeating structural unit β represented by the formula (2) and the repeating structural unit γ represented by the formula (3) in the diorganopolysiloxane. Is preferably from 2 to 2000, more preferably from 5 to 1000, and even more preferably from 20 to 500.

When the number of repeating structural units α represented by the above formula (1) is 2 or more, the plurality of R ₁ may be the same group or two or more different groups, and the plurality of B ₁ are the same. Or two or more different groups.

When the number of repeating structural units β represented by the above formula (2) is 2 or more, the plurality of R ₂ may be the same group or two or more different groups, and the plurality of D ₁ are the same. Or two or more different groups.

When the number of repeating structural units γ represented by the above formula (3) is 2 or more, the plurality of R ₃ may be the same group or two or more different groups, and the plurality of R ₄ are the same. Or two or more different groups.

Below, the specific example of the diorganopolysiloxane used for this invention is shown. However, the present invention is not limited to these specific examples. In addition, each of the following diorganopolysiloxanes 1 to 28 has a terminal group I (E ₁ : methyl group) having a structure represented by the above formula (4) as a terminal group and a structure represented by the above formula (5). It has a terminal group II (E ₂ , _{R 5} , R ₆ : methyl group).

  Among these, 2, 3, 7, 8, 9, 13, 15, 17, 19, 21, 22, 26 and 28 are preferable, and 3, 7, 8, 13, 15, 21, 22, 26 and 26 are particularly preferable. And 28 are more preferred.

  The weight average molecular weight of the diorganopolysiloxane used in the present invention is 1,000 to 1,000,000, preferably 10,000 to 200,000, more preferably 10,000 to 100,000, and further 20,000 to 40,000. Is more preferable. Although the measuring method of molecular weight is not limited, For example, in gel permeation chromatography (GPC), the weight average molecular weight (Mw) by polystyrene conversion can be measured.

  Moreover, it is preferable that content of the fluorine atom in the diorganopolysiloxane used for this invention is 1-90 mass% with respect to the diorganopolysiloxane total mass, and it is 5-60 mass% especially. Is preferred. When the fluorine atom content is less than 1% by mass, the release property of the surface layer of the electrophotographic photosensitive member may not be sufficiently exhibited. When the fluorine atom content exceeds 90% by mass, the binder resin in the surface layer of the electrophotographic photosensitive member may not be exhibited. If the surface of the electrophotographic photosensitive member becomes worn due to long-term use, sufficient effects can be obtained. It may disappear.

  In general, silicone oil and siloxane compounds have surface migration properties in the layer, so when the surface of an electrophotographic photoreceptor is worn due to long-term use, many of these components are lost and sufficient. The effect cannot be obtained.

In contrast, the diorganopolysiloxane used in the present invention has an anchor effect on the binder resin in the surface layer of the electrophotographic photosensitive member, particularly because the side chain D ₁ suppresses surface migration in the layer. Is done. For this reason, it is thought that it has an effect throughout the lifetime of an electrophotographic photoreceptor.

  In the present invention, by using the above diorganopolysiloxane in the charge transport layer, the releasability of the surface of the electrophotographic photosensitive member can be continuously improved, and toner and external additives can be added to the surface of the electrophotographic photosensitive member. The adhesion of the agent can be prevented, the cleaning property can be improved, and the occurrence of uneven rotation can be suppressed.

  In the electrophotographic photoreceptor used in the process of the present invention, the surface layer of the electrophotographic photoreceptor contains a compound having the repeating structural unit α represented by the formula (1) and the repeating structural unit β represented by the formula (2). As a result, the releasability of the surface of the electrophotographic photosensitive member is remarkably improved, so that excessive toner and external additives do not adhere to the electrophotographic photosensitive member, and the electrophotographic photosensitive member, the developing roller, the cleaning blade, etc. Contamination such as fusion or sticking hardly occurs even when rubbing or stopping with a member in contact with the photoconductor.

  Hereinafter, the structure of the electrophotographic photosensitive member used in the present invention will be described. The electrophotographic photoreceptor in the present invention has a photosensitive layer on a support. The photosensitive layer may be a single layer type containing a charge transport material and a charge generation material in the same layer, or may be a laminate type separated into a charge transport layer and a charge generation layer. preferable.

  The support to be used is not particularly limited as long as it has conductivity, and examples thereof include metals such as aluminum and stainless steel, metals provided with a conductive layer, paper, plastics, and the like, and examples of the shape include a sheet shape and a cylindrical shape.

  When the image input of LBP or the like is laser light, a conductive layer may be provided for the purpose of preventing interference fringes due to scattering or covering scratches on the support. This can be formed by dispersing conductive particles such as carbon black and metal particles in a binder resin. The thickness of the conductive layer is preferably 5 to 40 μm, particularly preferably 10 to 30 μm. In addition, interference fringe prevention can be performed by cutting a cylinder, anodizing, dry or wet blasting, and in that case, there is no need to provide a conductive layer.

  An intermediate layer having an adhesion function and a barrier function may be provided on the support or the conductive layer. Examples of the material for the intermediate layer include polyamide, polyvinyl alcohol, polyethylene oxide, ethyl cellulose, casein, polyurethane, and polyether urethane. These are dissolved in an appropriate solvent and applied. The thickness of the intermediate layer is preferably 0.05 to 5 μm, particularly preferably 0.3 to 1 μm. If the cylinder is directly anodized or a conductive film is formed by a sol-gel method, the intermediate layer may not be used.

  A charge generation layer is formed on the intermediate layer. Examples of the charge generating material used in the present invention include selenium-tellurium, pyrylium, thiapyrylium dyes, phthalocyanine, anthanthrone, dibenzpyrenequinone, trisazo, cyanine, disazo, monoazo, indigo, quinacridone, and asymmetric quinocyanine pigments. It is done.

  In the case of the functional separation type, the charge generation layer is composed of the above charge generation material with a binder resin and a solvent in an amount of 0.3 to 4 times, a homogenizer, an ultrasonic dispersion, a ball mill, a vibration ball mill, a sand mill, an attritor, a roll mill, and a liquid collision type It is sufficiently dispersed by a method such as a disperser, and the dispersion is applied and dried. It is also possible to add the binder resin after the charge generating material is dispersed or not to use the binder resin. The thickness of the charge generation layer is preferably 5 μm or less, particularly preferably 0.1 to 2 μm.

  The charge transport layer mainly includes a charge transport material and a binder resin. When the charge transport layer is a surface layer, the charge transport layer further includes a repeating structural unit α represented by the formula (1) and a repeating structural unit β represented by the formula (2). An organopolysiloxane is dissolved in a solvent, and the resulting coating is formed by coating and drying.

  Examples of the charge transport material used include triarylamine compounds, hydrazone compounds, stilbene compounds, pyrazoline compounds, oxazole compounds, triallylmethane compounds, and thiazole compounds.

  Examples of the binder resin used for the charge transport layer include thermoplastic binder resins and curable binder resins. Specifically, phenoxy resins, polyacrylamide resins, polyvinyl butyral resins, polyarylate resins, polysulfone resins, polyamide resins, Acrylic resin, acrylonitrile resin, methacrylic resin, vinyl chloride resin, vinyl acetate resin, phenol resin, epoxy resin, polyester resin, alkyd resin, polycarbonate resin, polyurethane resin or co-polymer containing two or more repeating units of these resins Examples thereof include styrene-butadiene copolymer, styrene-acrylonitrile copolymer, and styrene-maleic acid copolymer. It can also be selected from organic photoconductive polymers such as poly-N-vinylcarbazole, polyvinylanthracene, and polyvinylpyrene.

  Among these, the polyarylate resin and the polycarbonate resin are well-suited to the diorganopolysiloxane having the repeating structural unit α represented by the formula (1) and the repeating structural unit β represented by the formula (2), and have good coating properties. Since a working liquid can be produced, it is preferable. The polyarylate resin and the polycarbonate resin have structural units represented by the following formulas (A) and (B).

In the above formula (A), X ₁₁ is a carbon atom, a single bond (in this case, R ₅₅ and R ₅₆ are absent), R _{51 to} R ₅₄ are a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, or a substituted group Or an unsubstituted aryl group, and R ₅₅ and R ₅₆ are a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group, or a substituted or unsubstituted aryl group or R ₅₅ and R ₅₆ A group necessary for forming an unsubstituted alkylidene group is shown.

In the above formula (B), X ₂₁ is a carbon atom, a single bond (in this case, R ₆₅ and R ₆₆ are absent), R _{60 to} R ₆₄ are a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, or a substituted group Or an unsubstituted aryl group, wherein R ₆₅ and R ₆₆ are a primary atom, a halogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group or R ₆₅ and R ₆₆ bonded to each other; A group necessary for forming an unsubstituted alkylidene group is shown. R ₆₇ to ₇₀ represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group.

  In formulas (A) and (B), examples of the halogen atom include a fluorine atom, a chlorine atom, and an iodine atom. Examples of the alkyl group include a methyl group, an ethyl group, and a propyl group. Examples of the aryl group include Examples thereof include a phenyl group and a naphthyl group, and examples of the alkylidene group include a cyclohexylidene group.

  Examples of the substituent that these groups may have include halogen atoms such as fluorine atom, chlorine atom and iodine atom, alkyl groups such as methyl group, ethyl group and propyl group, and aryl groups such as phenyl group. It is done.

  Although the preferable example of the structural unit which a polycarbonate resin has is shown below, it is not restricted to these.

  Next, although the preferable example of the structural unit which polyarylate resin has is shown, it is not restricted to these.

  The thickness of the charge transport layer is preferably 5 to 50 μm, more preferably 10 to 30 μm. The mass ratio between the charge transport material and the binder resin is preferably 5: 1 to 1: 5, more preferably about 3: 1 to 1: 3. Examples of the application method include dip coating, spray coating, spinner coating, blade coating, and roll coating.

  Content of the diorganopolysiloxane which has the repeating structural unit (alpha) shown by Formula (1) and the repeating structural unit (beta) shown by Formula (2) is 0.01-40 mass parts with respect to a coating-film structural component. Particularly preferred is 1.0 to 30.0 parts by mass. If the content is too small, it is difficult to obtain the effects of the present invention. If the content is too large, carrier trapping will occur, and potential fluctuations are likely to occur.

  Since dyes, pigments, organic charge transport materials, and the like are generally vulnerable to dirt, metals, etc. in ultraviolet rays, ozone, oil, etc., a protective layer may be provided as necessary in the present invention. The protective layer that can be used in the present invention includes polyester resin, polycarbonate resin, acrylic resin, methacrylic resin, polyamide resin, polyimide resin, polyarylate resin, polyurethane resin, styrene-butadiene copolymer, styrene-acrylonitrile copolymer, and styrene-acrylic acid. A solution containing a binder resin such as a copolymer, a diorganopolysiloxane having a repeating structural unit α represented by the formula (1) and a repeating structural unit β represented by the formula (2) is coated on the photosensitive layer and dried. To form. Further, when a condensation monomer or a radical polymerization monomer having an unsaturated group is used as the binder resin, it may be cured and formed by applying energy light such as heat or ultraviolet light after coating. Moreover, you may further contain electroconductive particles, such as a metal and an electroconductive metal oxide, and charge transport material as needed.

  The thickness of the protective layer is preferably 0.05 to 20 μm. Since the protective layer can be made thinner than the charge transport layer, the amount of diorganopolysiloxane can be increased.

  The electrophotographic apparatus of the present invention will be described with reference to FIG. As an example of a copying machine and a printer as an electrophotographic apparatus of the present invention, there is an apparatus shown in FIG. 2, and a toner 61 is accommodated in the developing means 60. The toner is a magnetic toner or a non-magnetic toner.

Immediately after irradiating the pre-exposure 71, the surface of the electrophotographic photosensitive member 63 is charged by a charging means (charging roller) 62 to which a DC bias is applied by a bias applying means 62a, and exposed (for example, laser light, halogen lamp light, etc.). ) 64 to form an electrostatic latent image on the electrophotographic photosensitive member 63. Toner coating blade (for example, elastic blade, metal blade, etc.) 72, 10 ³ to 10 ⁹ Ω · cm accommodated in developing means 60 having developing roller 65 having a medium resistance elastic layer or dielectric layer on its surface. The electrostatic latent image is developed with the toner 61. For the development, a regular development system or a reverse development system is used. In the developing unit, a DC bias or an alternating bias is applied to the developing roller 65 by a bias applying unit 66 as necessary. When the transfer material P is conveyed and arrives at the transfer portion, the back surface (electrophotographic photoreceptor 63) of the transfer material P is transferred by a transfer means (for example, a transfer roller and a transfer belt) 67 to which a voltage is applied by a bias applying means 68. The toner image on the surface of the electrophotographic photosensitive member 63 is electrostatically transferred onto the transfer material P by charging while pressing from the opposite side). In some cases, the toner image on the electrophotographic photosensitive member 63 is transferred to an intermediate transfer member (not shown) (for example, an intermediate transfer drum and an intermediate transfer belt), and the toner image is transferred from the intermediate transfer member to the transfer material P. Also good.

  The toner image on the transfer material P separated from the electrophotographic photosensitive member 63 is fixed to the transfer material P by a heating and pressing unit (for example, a heating and pressing roller fixing unit). The toner remaining on the electrophotographic photosensitive member 63 after the transfer process is removed from the surface of the electrophotographic photosensitive member 63 by a cleaning unit (for example, a cleaning blade, a cleaning roller, and a cleaning brush) as necessary. After the cleaning, the electrophotographic photosensitive member 63 is irradiated with the pre-exposure 71 and then the process starting from the charging process by the charging means 62 is repeated.

  FIG. 3 is a schematic sectional view showing a specific example of the process cartridge taken out from the main body of the electrophotographic apparatus. In the process cartridge, the developing means and the electrostatic latent image holding member are at least integrally formed into a cartridge, and is formed so as to be detachable from an electrophotographic apparatus main body (for example, a copying machine and a laser beam printer). . In the process cartridge shown in FIG. 3, a developing roller (elastic roller) 19 is pressed against the developing device 15 so as to form a nip portion on the photosensitive drum 10. An application roller 12 is provided in pressure contact. Further, a charging roller 11 and a cleaning blade 13 are provided in pressure contact with the photosensitive drum 10.

  Hereinafter, it demonstrates according to an Example. “Part” means part by mass.

  First, the diorganopolysiloxane used in the present invention can be synthesized as follows.

(Synthesis Example 1)
3.23 g of polysiloxane represented by the following formula in the flask,

Chloroplatinic acid 20ppm (5% isopropyl alcohol solution), 14.7g of macromonomer shown below
_{Formula: CH 2 = CH-CH (} CH 2 CCH 3 COOC 4 H 9) 20 (CH 2 CCH 3 COOCH 3) 20 C 4 H 9
And 80 g of m-xylene hexafluoride were mixed and gradually heated. Further, the reaction was continued at 80 ° C. for 6 hours. Subsequently, the pressure was reduced to 20 Torr under the condition of 140 ° C. to remove the solvent and low boiling point components. Thus, when the obtained reaction product was analyzed by ²⁹ Si-NMR, ¹³ C-NMR and FT-IR, it was found to be a diorganopolysiloxane (weight average molecular weight 41000) represented by the following formula: found.

(Synthesis Example 2)
3.23 g of polysiloxane represented by the following formula in the flask,

20 ppm of chloroplatinic acid (5% isopropyl alcohol solution), 7.5 g of a macromonomer shown below,

And 80 g of m-xylene hexafluoride were mixed and gradually heated. Further, the reaction was continued at 80 ° C. for 6 hours. Subsequently, the pressure was reduced to 20 Torr under the condition of 140 ° C. to remove the solvent and low boiling point components. Thus, when the obtained reaction product was analyzed by ²⁹ Si-NMR, ¹³ C-NMR, and FT-IR, it was found to be a diorganopolysiloxane (weight average molecular weight 49000) represented by the following formula. found.

(Synthesis Example 3)
Instead of the macromonomer of Synthesis Example 2, 5.2 g of a compound represented by the following formula

A diorganopolysiloxane (weight average molecular weight 56000) represented by the following formula was obtained in the same manner as in Synthesis Example 2 except that was used.

(Synthesis Example 4)
Instead of the polysiloxane of Synthesis Example 2, a polysiloxane represented by the following formula

A diorganopolysiloxane (weight average molecular weight 49000) represented by the following formula was obtained in the same manner as in Synthesis Example 2 except that was used.

Example 1
A 30 mm x 357 mm aluminum cylinder is used as a support, and a coating composed of the following materials is applied to the support by a dipping method and thermally cured at 140 ° C. for 30 minutes to form a conductive layer with a thickness of 15 μm. did.

Conductive pigment: SnO ₂ coated barium sulfate 10 parts Resistance adjusting pigment: Titanium oxide 2 parts Binder resin: Phenol resin 6 parts Leveling agent: Silicone oil 0.001 part Solvent: Methanol / methoxypropanol = 0.2 / 0. 8 20 copies

  Next, a solution prepared by dissolving 3 parts of N-methoxymethylated nylon and 3 parts of copolymer nylon in a mixed solvent of 65 parts of methanol / 30 parts of n-butanol was applied by a dipping method to a film thickness of 0.5 μm. An intermediate layer was formed.

  Next, 9 parts of a hydroxygallium phthalocyanine crystal having a strong peak at 7.4 ° ± 0.2 and 28.2 ° ± 0.2 in the X-ray diffraction of CuKα and polyvinyl butyral (trade name: ESREC BX) −1, manufactured by Sekisui Chemical Co., Ltd.) in 100 parts of tetrahydrofuran was dispersed in a sand mill using 1 mmφ glass beads for 3 hours. 200 parts of butyl acetate was added thereto, diluted and recovered, and this was dip-coated on the intermediate layer and dried at 100 ° C. for 10 minutes to form a charge generation layer having a thickness of 0.30 μm. .

  Next, in order to form a charge transport layer, a paint for charge transport was prepared. Polyarylate resin (weight average molecular weight 128000) of structural unit example (B-2), amine compounds a and b represented by the following formulae

In addition, the organopolysiloxane of Synthesis Example 1 was prepared such that the final mass ratio was polyarylate resin 10, amine compound a7, amine compound b1, diorganopolysiloxane 0.9, and solvent 80.

  The solvent was prepared so that the final mass ratio of monochlorobenzene: dimethoxymethane was 6: 4. This paint was applied by a dip coating method and dried at 130 ° C. for 1 hour to form a charge transport layer having a thickness of 15 μm.

For the evaluation, a Canon color laser printer LBP-5500 was modified and used. In the remodeling, motors were changed so that the process speed could be doubled. The bright part potential and dark part potential of the electrophotographic photosensitive member during printing were adjusted to be the same as before modification. Evaluation was performed by first outputting an image in a low temperature and low humidity (0 ° C./10% RH) environment. As for the image, three units of A4 solid black images, three halftones, and ten solid whites were taken as one unit, and 15 units were repeatedly output continuously. This image was visually judged to evaluate cleaning failure. Further, after outputting the image, the portion immediately after passing the cleaning blade on the electrophotographic photosensitive member was observed with a microscope, and the presence or absence of slipped toner was confirmed. Further, images having a printing rate of 1% were continuously output under the same environment, and the same image evaluation and electrophotographic photoreceptor surface observation were performed after 2000 sheets and 10,000 sheets. Evaluation was performed as follows. The results are shown in Table 1.
A: No abnormality (both electrophotographic photosensitive member and image are poorly cleaned on the entire surface, no slipping)
○: No abnormality on the image. Only a slight amount of toner is observed on the electrophotographic photosensitive member.
(Triangle | delta): The very slight cleaning defect generate | occur | produces on an image and a slip-through toner is observed on an electrophotographic photoreceptor.
× Δ: Cleaning failure occurred on the image.
×: A poor cleaning level occurs on the image.

(Example 2)
Evaluation was performed in the same manner as in Example 1 except that the mass ratio of the diorganopolysiloxane in the charge transport layer in Example 1 was 1.8. The results are shown in Table 1.

(Example 3)
Evaluation was performed in the same manner as in Example 1 except that the mass ratio of the diorganopolysiloxane in the charge transport layer in Example 1 was 5.4. The results are shown in Table 1.

Example 4
An electrophotographic photoreceptor was prepared and evaluated in the same manner as in Example 2 except that Synthesis Example 1 was changed to Synthesis Example 2 as the diorganopolysiloxane in the charge transport layer of Example 2. The results are shown in Table 1.

(Example 5)
An electrophotographic photoreceptor was prepared and evaluated in the same manner as in Example 2 except that Synthesis Example 1 was changed to Synthesis Example 3 as the diorganopolysiloxane in the charge transport layer of Example 2. The results are shown in Table 1.

(Example 6)
Example 5 is the same as Example 5 except that the resin of the structural unit example (A-3) (weight average molecular weight 106000) is used instead of the binder resin of the structural unit example (B-2) in the charge transport layer. Was evaluated. The results are shown in Table 1.

(Comparative Example 1)
Evaluation was performed in the same manner as in Example 1 except that the diorganopolysiloxane in the charge transport layer was not added in Example 1. The results are shown in Table 1.

(Comparative Example 2)
Evaluation was performed in the same manner as in Example 1 except that a silicone compound (trade name: GS101, Toa Gosei) was used in place of the diorganopolysiloxane in the charge transport layer in Example 1. The results are shown in Table 1.

(Comparative Example 3)
In Comparative Example 1, instead of the final mass ratio 10 of the binder resin of the structural unit example (B-2) in the charge transport layer, the structural unit example (A-3), the following structure a and the structural unit example (A-3) Evaluation was performed in the same manner as in Comparative Example 1 except that the copolymer binder resin (copolymerization ratio 1/9, weight average molecular weight 110000) was used at 9: 1. The results are shown in Table 1.

(Comparative Example 4)
Evaluation was performed in the same manner as in Example 1 except that the compound represented by the following structural formula was used in place of the diorganopolysiloxane in the charge transport layer in Example 2. The results are shown in Table 1.

(Comparative Example 5)
A coating solution was prepared in the same manner as in Example 3 except that the compound used in Comparative Example 4 was used in place of the diorganopolysiloxane in the charge transport layer in Example 3. The liquid was slightly separated after a few days.

It is a figure which shows the example of schematic structure of the process which has the electrophotographic photoreceptor of this invention. 1 is a diagram illustrating an example of a schematic configuration of an electrophotographic apparatus including a process cartridge having the electrophotographic photosensitive member of the present invention. It is a figure which shows the example of schematic structure of the process cartridge which has the electrophotographic photoreceptor of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 8 Coating blade 10 Photosensitive drum 11 Charging roller 12 Coating roller 13 Cleaning blade 15 Developer 19 Developing roller (elastic roller)
60 Developing means 61 Toner 62 Charging means (charging roller)
62a Bias applying means 63 Electrophotographic photosensitive member 64 Exposure light 65 Developing roller 67 Transfer means 66, 68 Power supply 70 Cleaning means 71 Pre-exposure 72 Toner coating blade P Transfer material

Claims (9)

In the electrophotographic photosensitive member having a photosensitive layer on a support, the surface layer of the electrophotographic photosensitive member includes a repeating structural unit α represented by the following formula (1) and a repeating structural unit β represented by the following formula (2). An electrophotographic photoreceptor comprising a diorganopolysiloxane having a weight average molecular weight of 1,000 to 1,000,000;

(In the above formulas (1) and (2), R ₁ and R ₂ each independently represents a substituted or unsubstituted monovalent hydrocarbon group, and B ₁ is a monovalent organic group having a perfluoroalkyl group. D ₁ represents a monovalent organic group containing a repeating unit represented by the following formula (11) or (21).

(In the above formula (11), R ₁₁ and R ₁₂ represent a hydrogen atom, a substituted or unsubstituted monovalent hydrocarbon group. N represents an integer of 3 or more),

(In the above formula (21), R ₂₁ represents a single bond, a carbonyl group, an ether group, a thioether group or a —C (R ₃₄ ) (R ₃₅ ) — group (R ₃₄ and R ₃₅ are each independently a hydrogen atom, A substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted cycloalkylidene group formed by combining R ₃₄ and R _35. ) R _{22 to} R ₂₉ are each independently selected. Represents a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group, n represents an integer of 3 or more, and X represents —CO— or the following formula (X1).

(In the formula (X1), R _{30 to} R ₃₃ each independently represents a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group). The electrophotographic photoreceptor according to claim 1, wherein D ₁ has a repeating unit represented by the formula (11), and R ₁₂ is a hydrogen atom or a methyl group. The electrophotographic photoreceptor according to claim 1, wherein the D ₁ has a repeating unit represented by the formula (21), and the formula (X1) is represented by the following formula (X2).
The electrophotographic photosensitive member according to claim 1, wherein D ₁₁ has a repeating unit represented by the formula (21), and X is —CO—.   The electrophotographic photosensitive member according to claim 1, wherein the binder resin in the surface layer of the electrophotographic photosensitive member is polycarbonate.   The electrophotographic photosensitive member according to claim 1, wherein the binder resin in the surface layer of the electrophotographic photosensitive member is polyarylate.   The electrophotographic photosensitive member according to any one of claims 1 to 6, wherein the content of fluorine atoms in the diorganopolysiloxane is 1 to 90% by mass with respect to the total mass of the diorganopolysiloxane.   8. The electrophotographic photosensitive member according to claim 1, charging means for charging the electrophotographic photosensitive member, developing means for developing the electrophotographic photosensitive member on which an electrostatic latent image is formed with toner, and a transfer step A process cartridge characterized in that it integrally supports at least one means selected from the group consisting of cleaning means for collecting toner remaining on a later electrophotographic photosensitive member, and is detachable from the electrophotographic apparatus main body. .   An electrophotographic photosensitive member according to any one of claims 1 to 7, a charging means for charging the electrophotographic photosensitive member, an exposure means for exposing the charged electrophotographic photosensitive member to form an electrostatic latent image, An electrophotographic apparatus comprising: a developing unit that develops toner on an electrophotographic photosensitive member on which a latent image is formed; and a transfer unit that transfers a toner image on the electrophotographic photosensitive member onto a transfer material.