JP2006154631A - Electrophotographic apparatus and processing cartridge - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrophotographic apparatus of high image quality in which prevention of electrifying stripes and prevention of a rainy cleaning defect image are made compatible with each other without the occurrence of a slip even if a photoreceptor having a high cleaning performance and an electrifying member having high electrifying uniformity are simultaneously used, and to provide a processing cartridge. <P>SOLUTION: The electrophotographic apparatus is equipped with the photoreceptor, an electrifying means for electrifying the photoreceptor by applying only the DC voltage to the electrifying member having a conductive elastic layer and a surface layer, an exposing means for forming an electrostatic latent image by exposing the electrified photoreceptor, a developing means for developing the electrostatic latent image, a transferring means for transferring the developed image, and a cleaning means for cleaning the developer remaining on the photoreceptor, in which the contact angle of the surface of the photoreceptor with pure water is ≥105° and the coefficient of kinetic friction is 0.6 to 1.2; the ten point average roughness (Rzjis) of the surface layer of the electrifying member is 5 to 10 μm; and the average length (RSm) is 10 to 70 μm, and the processing cartridge. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an electrophotographic apparatus and a process cartridge, and more particularly to an electrophotographic apparatus and a process cartridge including an electrophotographic photosensitive member having a specific surface layer and a charging member having a specific surface layer.

  In an image forming process using an electrophotographic apparatus, an electrophotographic photoreceptor undergoes repeated processes of charging, exposure, development, transfer, cleaning, and charge removal. The electrostatic latent image formed by charging and exposure becomes a toner image by a fine particle developer called toner. Further, the toner image is transferred to a transfer material such as paper in the transfer process, but 100% of the toner is not transferred, and a part of the toner image remains on the electrophotographic photosensitive member. If this residual toner is not removed, a high-quality image free from dirt or the like cannot be obtained in the repeated process. Therefore, a residual toner cleaning process is required. As a cleaning process, a process using a fur brush, a magnetic brush, a blade, or the like is representative, but blade cleaning is generally selected in terms of cleaning accuracy, apparatus configuration, and the like. In blade cleaning, an elastic member made of a material such as polyurethane is configured to press-contact the electrophotographic photosensitive member perpendicularly to the traveling direction of the electrophotographic photosensitive member, and in order to increase toner cleaning accuracy, Although it is necessary to increase the contact pressure of the blade to the electrophotographic photosensitive member, this causes an increase in the frictional force between the two. As a result, problems such as a decrease in durability due to an increase in the shaving amount of the electrophotographic photosensitive member, generation of scratches on the electrophotographic photosensitive member, occurrence of cleaning failure due to blade reversal, and stoppage of the apparatus occur. When the contact pressure of the blade to the electrophotographic photosensitive member is insufficient, the toner slips through the blade, resulting in a rainy defective cleaning image.

  As means for improving the cleaning performance of the electrophotographic photosensitive member in order to prevent the toner from slipping out without increasing the contact pressure of the blade, the surface layer of the electrophotographic photosensitive member may contain a silicone resin or fluorine atom-containing resin particles. It is known that the releasability of the toner is improved by dispersing (fluororesin powder) to increase the water repellency of the surface of the electrophotographic photosensitive member.

  However, when the surface layer of the electrophotographic photosensitive member contains a silicone resin or the fluorine atom-containing resin particles are dispersed, the water repellency of the surface of the electrophotographic photosensitive member is improved and the surface friction is improved. It is known that a decrease in coefficient occurs.

  On the other hand, the electrophotographic apparatus includes means for uniformly charging a member to be charged such as primary charging means for charging the image bearing member. As a charging method, a contact charging method that generates significantly less ozone than the conventional corona charging method has been studied and put into practical use. The contact charging method is a method in which a charged member to which a voltage is applied is brought into contact with a member to be charged to charge the member to be charged. Is generally charged. As the contact-type charging member, one having a structure including at least two surface layers in contact with the member to be charged is used widely in the elastic layer. An important characteristic of the contact charging member is charging uniformity with respect to the electrophotographic photosensitive member. As a method of improving the uniformity, uniform distribution of resistance and improvement of surface properties are being studied. For example, with respect to the former, each layer constituting the contact charging member using a resin having a relatively low volume resistivity as a binding material for the contact charging member surface layer, which improves the dispersion of the conductive substance in the contact charging member surface layer. A measure such as uniformly adjusting the film thickness of the film is mentioned. As for the latter, there are measures such as adding a leveling agent to the surface layer of the contact charging member and improving the surface property of the elastic layer of the contact charging member. Further, in Patent Document 1, it is proposed that uniform chargeability can be obtained even when the object to be charged is charged by applying only a DC voltage by setting the surface roughness of the outermost layer of the contact charging member to 5 μm or less. In Patent Document 2, uniformity of the charging potential is always ensured by setting the surface roughness of the contact charging member to 20 μm or less on the 10-point average surface roughness Rz scale measured based on JIS standard B-0601. However, it has been proposed that a good image can be obtained.

However, if the surface of the charging member is roughened to an appropriate range for the purpose of improving the charging uniformity in this way, the contact area between the charging member and the electrophotographic photosensitive member decreases, and the charging member and There is a tendency for the coefficient of friction with the electrophotographic photoreceptor to decrease. In particular, for the purpose of improving the cleaning performance as described above, an electrophotographic photosensitive member containing a silicone resin, fluorine atom-containing resin particles or the like to increase the water repellency of the electrophotographic photosensitive member surface and at the same time the surface friction coefficient is lowered. When the photoconductor is used, the friction coefficient between the electrophotographic photosensitive member and the charging member is insufficient, causing the charging member to slip without being driven by the electrophotographic photosensitive member, causing uneven rotation and stopping the rotation. If this happens, the chargeability will be significantly reduced. As the process speed increases as the electrophotographic apparatus further increases in speed, the charging member tends to slip.
JP-A-5-341620 JP-A-8-286468

  The object of the present invention is to achieve both prevention of charging stripes and prevention of rain-like cleaning defective images without causing slippage even when an electrophotographic photosensitive member having high cleaning performance and a charging member having high charging uniformity are used simultaneously. Another object of the present invention is to provide a high-quality electrophotographic apparatus and a process cartridge.

  According to the present invention, there is provided a charging member having an electrophotographic photosensitive member, a conductive elastic layer disposed in contact with the electrophotographic photosensitive member, and a surface layer provided on the conductive elastic layer. A charging means for charging the electrophotographic photosensitive member by applying a voltage of only a direct current voltage, and the electrophotographic photosensitive member by irradiating the surface of the electrophotographic photosensitive member charged by the charging means with exposure light. An exposure means for forming an electrostatic latent image on the surface of the body, and the surface of the electrophotographic photoreceptor by developing the electrostatic latent image on the surface of the electrophotographic photoreceptor formed by the exposure means with toner A developing unit for forming a toner image on the surface, a transfer unit for transferring the toner image on the surface of the electrophotographic photosensitive member formed by the developing unit to a transfer material, and the electrophotographic image after transfer by the transfer unit. Photosensitivity And a cleaning means for cleaning the surface of the electrophotographic photosensitive member by removing toner remaining on the surface of the electrophotographic photosensitive member, wherein the contact angle of the surface of the electrophotographic photosensitive member with respect to pure water is 105 °. The coefficient of dynamic friction is 0.6 or more and 1.2 or less, the ten-point average roughness (Rzjis) of the surface of the charging member is 5.0 μm or more and 10.0 μm or less, and the average length An electrophotographic apparatus and a process cartridge are provided in which the thickness (RSm) is 10.0 μm or more and 70.0 μm or less.

  According to the present invention, an electrophotographic apparatus capable of preventing charging streaks and rain-like defective images without causing slip even when using a charging member with high charging uniformity and maintaining high cleaning performance through durable use, and It became possible to provide a process cartridge.

  Hereinafter, embodiments of the present invention will be described.

(1) Electrophotographic apparatus FIG. 1 shows an example of a schematic configuration of an electrophotographic apparatus according to the present invention.

  Reference numeral 1 denotes an electrophotographic photosensitive member of a drum type. The electrophotographic photosensitive member 1 is rotationally driven in the direction of arrow A with a predetermined peripheral speed (process speed).

  A charging roller 2 is a contact charging member as a charging unit. The charging roller 2 rotates following the rotation of the electrophotographic photosensitive member 1 press-fitted to the charging roller, and only a DC voltage is applied from the bias power source 2A. The charging roller 2 charges the peripheral surface of the electrophotographic photosensitive member 1 with a predetermined polarity and potential uniformly by a contact charging method.

  The surface of the electrophotographic photosensitive member 1 is irradiated with the exposure light 3 of the target image information by an exposure unit (image forming exposure unit for a document image, a laser beam scanner, etc.) (not shown) on the charged surface of the electrophotographic photosensitive member 1. An electrostatic latent image corresponding to the target image information is formed.

  The formed electrostatic latent image is visualized as a transferable particle image (toner image) 5a by regular development or reversal development with the charged particles (toner) 5 of the developing device 4.

  Next, the toner image is transferred from the sheet feeding cassette 9 to the sheet feeding roller 10 and the resist at the nip portion (transfer section) between the electrophotographic photosensitive member 1 and the transfer roller 7 as a transfer means press-fitted to the electrophotographic photosensitive member. The transferred particles 5b adhere to the transfer material 6 fed one by one by the roller 11 at a predetermined timing. A bias voltage having a polarity opposite to the charge held in the toner 5 is applied to the transfer roller 7 from a bias power source 7A.

  The transfer material 6 that has received the toner image transfer is separated from the surface of the electrophotographic photosensitive member 1 and conveyed to a fixing means (not shown) to undergo a toner image fixing process.

  The surface of the electrophotographic photosensitive member 1 after the transfer of the toner image is subjected to removal of adhering contaminants such as transfer residual toner by a cleaner (cleaning device) 8 to be cleaned and repeatedly used for image formation.

  FIG. 2 shows an example of a contact charging type full-color electrophotographic apparatus having a plurality of electrophotographic photosensitive members, a charging member, and a developing device. In this full-color electrophotographic apparatus, process cartridges similar to those shown in FIG. 1 containing toner of each color (black, cyan, magenta, and yellow) are arranged in a vertical arrangement, sequentially transferred by respective transfer means, and finally fixed. This is a full-color electrophotographic apparatus called a tandem type. 20K, 20C, 20M and 20Y are process cartridges for each color, 21K, 21C, 21M and 21Y are electrophotographic photosensitive members, 22K, 22C, 22M and 22Y are charging rollers, 23 is a transfer roller, 24 is a conveyor belt, and 25 is a laser. A light source, 26 is toner, 27 is a fixing device, and 28 is a paper feed roller.

(2) Charging member The charging member used in the electrophotographic apparatus of the present invention has a ten-point average roughness (Rzjis) of the surface layer of 5.0 μm to 10.0 μm and an average length (RSm) of 10. It is 0 μm or more and 70.0 μm or less.

  By setting the surface of the charging member within the above range, an appropriate discharge starting point is formed between the electrophotographic photosensitive member and the charging member. It seems that the discharge is suppressed and the electrophotographic photosensitive member can be uniformly charged.

  If the surface roughness of the charging member is below the range defined in the present invention, sufficient charging uniformity cannot be obtained, and streaky image defects are likely to occur. On the other hand, when the surface roughness of the charging member exceeds the range specified in the present invention, paper dust, toner, and the like are likely to adhere to the charging member surface due to continuous paper passing, and image defects due to charging unevenness due to this will occur. .

  In addition, the charging member may have a suitable shape of the conductive member depending on the shape of the member to be charged. Hereinafter, preferred embodiments of the charging member will be described in detail with reference to the drawings.

  An example of the charging member is a roller shape as shown in FIG. 3, and is formed on the outer periphery of the charging support 2a, the conductive elastic layer 2b integrally formed on the outer periphery thereof, and the conductive elastic layer. A conductive member composed of the resistance layer 2c and the surface layer 2d formed on the outer periphery of the resistance layer 2c can be exemplified.

  As another example of the charging member, there may be two layers including a conductive elastic layer 2b and a surface layer 2d as shown in FIG. 4, or a resistance layer 2c and a surface layer 2d as shown in FIG. It is good also as a structure which formed four or more layers which provided the 2nd resistance layer 2e in the meantime on the electroconductive support body.

  As the conductive support 2a, a round bar made of a metal material such as iron, copper, stainless steel, aluminum and nickel can be used. Furthermore, these metal surfaces may be plated for the purpose of providing rust prevention and scratch resistance, but it is necessary not to impair the conductivity. In addition, the form of the conductive support used in the present invention can be selected depending on the form of the conductive member. For example, in the case of the belt-like conductive member described above, an aluminum thin film or the like is exemplified as the conductive support. Can do.

The conductive elastic layer is adjusted to less than 10 ⁸ Ω · cm by appropriately adding a conductive agent such as carbon black, conductive metal oxide, alkali metal salt, ammonium salt into an elastic material such as rubber. preferable.

  Further, the elasticity and hardness of the conductive elastic layer are adjusted by adding softening oil, plasticizer, etc. and foaming the resin. Specific elastic materials for the conductive elastic layer include, for example, natural rubber, EPDM, SBR, silicone rubber, urethane rubber, epichlorohydrin rubber, synthetic rubber such as IR, BR, NBR, and CR, as well as polyamide resin, polyurethane resin, and the like. A silicone resin etc. are also mentioned. A foam obtained by foaming these elastic materials may be used for the conductive elastic layer.

  The resistance layer is formed at a position in contact with the conductive elastic layer, and is provided as necessary for the purpose of preventing bleed-out to the surface of the conductive member such as softening oil and plasticizer contained in the conductive elastic layer. It is done. Examples of the material constituting the resistance layer used in the present invention include epichlorohydrin rubber, NBR, urethane rubber, polyolefin-based thermoplastic elastomer, urethane-based thermoplastic elastomer, polystyrene-based thermoplastic elastomer, fluororubber-based thermoplastic elastomer, polyester-based material. Examples include thermoplastic elastomers, polyamide thermoplastic elastomers, polybutadiene thermoplastic elastomers, ethylene vinyl acetate thermoplastic elastomers, polyvinyl chloride thermoplastic elastomers, and chlorinated polyethylene thermoplastic elastomers. These materials may be used alone or in combination of two or more, and may be a copolymer.

  The resistance layer used in the present invention has conductivity or semiconductivity. Various conductive agents (conductive carbon, conductive tin oxide, conductive titanium oxide, copper, aluminum, nickel, iron powder, alkali metal salt, ammonium salt, etc.) are appropriately used for the expression of conductivity and semiconductivity. Can be used. In this case, in order to obtain a desired electric resistance, two or more kinds of the various conductive agents may be used in combination.

  As the binder resin material for the surface layer used in the present invention, fluororesin, polyamide resin, acrylic resin, polyurethane resin, silicone resin, butyral resin, styrene-ethylene / butylene-olefin copolymer (SEBC) and olefin-ethylene are used. -Butylene-olefin copolymer (CEBC) etc. are mentioned. Various conductive agents (conductive carbon, conductive tin oxide, conductive titanium oxide, copper, aluminum, nickel, etc.) can be used as appropriate for the surface layer. In this case, in order to obtain a desired electric resistance, two or more kinds of the various conductive agents may be used in combination.

  In addition, what is necessary is just to form these layers mentioned above using the conventionally known layer formation technique so that it may become a suitable layer thickness according to each role.

  The method for controlling the surface roughness of the charging member to a predetermined range is not particularly specified, but for example, a method of adding fine particles to the surface layer, a method of using a polishing agent or a mechanical polishing method such as a sandblast method Any of them may be used.

(3) Electrophotographic photoreceptor In the electrophotographic apparatus of the present invention, the contact angle of the surface of the electrophotographic photoreceptor with respect to pure water is 105 ° or more and the friction coefficient is 0.6 or more and 1.2 or less. Even when used in combination with the above-described charging member having excellent uniformity, the charging member can be prevented from slipping without being driven by the electrophotographic photosensitive member, and high cleaning performance can be maintained. . As described above, in the electrophotographic apparatus of the present invention, the charging member used in combination with the electrophotographic photosensitive member has a 10-point average roughness (Rzjis) of the surface layer of 5.0 μm to 10.0 μm and an average length. (RSm) is 10.0 μm or more and 70.0 μm or less, and particularly when the friction coefficient of the surface layer of the electrophotographic photosensitive member is 0.6 or more and 0.7 or less, the surface layer is sufficiently thick. It is more preferable to use in combination with a charging member having a point average roughness (Rzjis) of 5.0 μm or more and 8.0 μm or less and an average length (RSm) of 20.0 μm or more and 40.0 μm or less. When the friction coefficient of the surface layer of the body is 0.7 or more and 1.2 or less, the ten-point average roughness (Rzjis) of the surface layer is 7.0 μm or more and 1.2 μm or less, and the average length (RSm) 30.0μm or more 60.0μ It is more preferable to use in combination with at a charging member or less.

  Further, the surface layer of the electrophotographic photosensitive member has a repeating structural unit α represented by the following formula (11) and a repeating structural unit β represented by the following formula (12), and has a weight average molecular weight of 1,000 to 1,000,000. An organopolysiloxane is contained, and the content of the diorganopolysiloxane in the surface layer is 0.01 to 20% by mass relative to the total mass of the surface layer (provided that the surface layer is a fluorine atom-containing resin). (Except for the case of containing particles), preferably 0.1 to 10.0 parts by mass. If the content is too small, it is difficult to obtain the effects of the invention. If the content is too large, carrier trapping may occur and potential fluctuation may occur. Inclusion of fluorine atom-containing resin fine particles in the surface layer of the electrophotographic photosensitive member may cause an excessive reduction in the coefficient of surface friction, and the fluorine atom-containing resin fine particles may scatter exposure light, resulting in sharp static electricity. Since it may be difficult to obtain a latent image, the surface layer of the electrophotographic photosensitive member of the present invention does not contain fluorine atom-containing resin fine particles.

  As a result, the water repellency of the surface of the electrophotographic photosensitive member can be improved without causing an excessive reduction of the coefficient of surface friction, and even when used in combination with a charging member with high charging uniformity, cleaning does not occur. The toner releasability at the time can be made sufficiently high.

上記式（１１）、（１２）中、Ｒ^１１及びＲ^１２は、それぞれ独立に、置換若しくは無置換の１価の炭化水素基を示し、Ｂ^１１は、パーフルオロアルキル基を有する１価の有機基を示し、Ｄ^１１は、重合度３以上の置換若しくは無置換のポリスチレン鎖を有する１価の有機基、置換若しくは無置換のアルキレンオキシ基を有する１価の有機基及び炭素原子数１２以上の１価の有機基からなる群より選択される１価の基を示す。

In the above formulas (11) and (12), R ¹¹ and R ¹² each independently represent a substituted or unsubstituted monovalent hydrocarbon group, and B ¹¹ is a monovalent organic group having a perfluoroalkyl group. D ¹¹ represents a monovalent organic group having a substituted or unsubstituted polystyrene chain having a degree of polymerization of 3 or more, a monovalent organic group having a substituted or unsubstituted alkyleneoxy group, and 12 or more carbon atoms. A monovalent group selected from the group consisting of monovalent organic groups is shown.

  The diorganopolysiloxane may further have a repeating structural unit γ represented by the following formula (13).

上記式（１３）中、Ｒ^１３及びＲ^１４は、それぞれ独立に、置換若しくは無置換の１価の炭化水素基を示す。

In the above formula (13), R ¹³ and R ¹⁴ 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 (14) and a terminal group II having a structure represented by the following formula (15).

上記式（１４）、（１５）中、Ｒ^１５及びＲ^１６は、それぞれ独立に、置換若しくは無置換の１価の炭化水素基を示し、Ｅ^１１及びＥ^１２は、それぞれ独立に、置換若しくは無置換の１価の炭化水素基、パーフルオロアルキル基を有する１価の有機基、重合度３以上の置換若しくは無置換のポリスチレン鎖を有する１価の有機基、置換若しくは無置換のアルキレンオキシ基を有する１価の有機基、置換若しくは無置換のシロキサン鎖を有する１価の有機基及び炭素原子数１２以上の１価の有機基からなる群より選択される１価の基を示し、ただし、上記式（１４）中のＥ^１１は上記ジオルガノポリシロキサンが有する繰り返し構造単位の主鎖（−Ｓｉ−Ｏ−）中のＳｉと結合し、上記式（１５）中のＳｉは上記ジオルガノポリシロキサンが有する繰り返し構造単位の主鎖（−Ｓｉ−Ｏ−）中のＯと結合する。

In the above formulas (14) and (15), R ¹⁵ and R ¹⁶ each independently represent a substituted or unsubstituted monovalent hydrocarbon group, and E ¹¹ and E ¹² 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. And a monovalent group selected from the group consisting of a monovalent organic group having a monovalent organic group having a substituted or unsubstituted siloxane chain and a monovalent organic group having 12 or more carbon atoms, provided that ^{E 11} in formula (14) is bonded to Si in the main chain of the repeating structural unit having the above diorganopolysiloxane (-Si-O-), Si in the formula (15) above diorganopolysiloxane Binds to O in the backbone of repeating structural units (-Si-O-) with.

  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 ^{11 to} R ¹⁶ 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 or a phenyl group.

The monovalent organic group having a B ¹¹ perfluoroalkyl group is preferably a monovalent group having a structure represented by the following formula (2).

上記式（２）中、Ｒ^２１は、アルキレン基又はアルキレンオキシアルキレン基を示し、ａは、３以上の整数を示す。

In the above formula (2), R ²¹ represents an alkylene group or an alkyleneoxyalkylene group, and a represents an integer of 3 or more.

  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.

A monovalent organic group having a polymerization degree of 3 or more substituted or unsubstituted polystyrene chain of the D ¹¹ is preferably a monovalent group having a structure represented by the following formula (3).

上記式（３）中、Ｒ^３１は、置換若しくは無置換の２価の炭化水素基を示し、Ｒ^３２、Ｒ^３３は、それぞれ独立に、置換若しくは無置換のアルキル基又は置換若しくは無置換のアリール基を示し、Ｗ^３１は、重合度３以上の置換若しくは無置換のポリスチレン鎖を示し、Ｒ^３４は、置換若しくは無置換のアルキル基又は置換若しくは無置換のアリール基を示し、ｂは、０又は１を示す。

In the above formula (3), R ³¹ represents a substituted or unsubstituted divalent hydrocarbon group, and R ³² and R ³³ each independently represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group. W ³¹ represents a substituted or unsubstituted polystyrene chain having a degree of polymerization of 3 or more, R ³⁴ represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group, b is 0 or 1 is shown.

  As said bivalent hydrocarbon group, alkylene groups, such as a methylene group, ethylene group, and a propylene group, are mentioned, It is preferable that it is C1-C10. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, and a butyl group. The aryl group is preferably unsubstituted, and examples thereof include a phenyl group.

The monovalent organic group having a substituted or unsubstituted alkyleneoxy group of D ¹¹ is preferably a monovalent group having a structure represented by the following formula (4).

上記式（４）中、Ｒ^４１及びＲ^４２は、それぞれ独立に、置換若しくは無置換の２価の炭化水素基を示し、Ｒ^４３は、水素原子又は置換若しくは無置換の１価の炭化水素基を示し、ｃは、０又は１を示し、ｄは、１以上３００以下の整数を示す。

In the above formula (4), R ⁴¹ and R ⁴² each independently represent a substituted or unsubstituted divalent hydrocarbon group, and R ⁴³ represents a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group. , C represents 0 or 1, and d represents an integer of 1 to 300.

  Examples of the divalent hydrocarbon group include alkylene groups such as methylene group, ethylene group and propylene group, and arylene groups such as phenylene group. Examples of the monovalent hydrocarbon group include alkyl groups such as a methyl group, an ethyl group, and a propyl group, and aryl groups such as a phenyl group. The d is preferably 5 or more.

Examples of the monovalent organic group having 12 or more carbon atoms of D ¹¹ include alkyl groups such as n-dodecyl group, n-tetradodecyl group, n-hexadecyl group and n-octadecyl group. The number of carbon atoms is preferably 100 or less.

  Examples of the substituent that each group may have include a halogen atom such as a fluorine atom, a chlorine atom and an iodine atom, an alkyl group such as a methyl group, an ethyl group and a propyl group, and an aryl group such as a phenyl group. Can be mentioned.

  The number (average) of repeating structural units α represented by the above formula (11) in the diorganopolysiloxane is preferably 1 to 1000, and particularly preferably 10 to 200.

  The number (average) of repeating structural units β represented by the above formula (12) in the diorganopolysiloxane is preferably 1 to 1000, and particularly preferably 5 to 100.

  The number (average) of repeating structural units γ represented by the above formula (13) in the diorganopolysiloxane is preferably 0 to 1000, particularly preferably 100 to 200.

  The repeating structural unit possessed by the diorganopolysiloxane is the repeating structural unit α represented by the above formula (11) and the repeating structural unit β represented by the above formula (12) or the repeating structural unit represented by the above formula (11). It is preferable that there are only the structural unit α, the repeating structural unit β represented by the above formula (12), and the repeating structural unit γ represented by the above formula (13).

  Sum (average) of the repeating structural unit α represented by the above formula (11), the repeating structural unit β represented by the above formula (12) and the repeating structural unit γ represented by the above formula (13) in the diorganopolysiloxane. Is preferably from 2 to 2000, particularly 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 (11) is 2 or more, the plurality of R ¹¹ may be the same group or two or more different groups, and the plurality of B ¹¹ are the same. Or two or more different groups.

When the number of repeating structural units β represented by the above formula (12) is 2 or more, the plurality of R ¹² may be the same group or two or more different groups, and the plurality of D ¹¹ are the same. Or two or more different groups. D ¹¹ is a monovalent organic group having a substituted or unsubstituted polystyrene chain having a polymerization degree of 3 or more, a monovalent organic group having a substituted or unsubstituted alkyleneoxy group, a substituted or unsubstituted siloxane as described above. Any one of a monovalent organic group having a chain and a monovalent organic group having 12 or more carbon atoms, and when there are a plurality of D ¹¹ , at least one D ¹¹ is a substituted or unsubstituted siloxane chain. It is preferably a monovalent organic group having

When the number of repeating structural units γ represented by the above formula (13) is 2 or more, the plurality of R ¹³ may be the same group or two or more different groups, and the plurality of R ¹⁴ are the same. Or two or more different groups.

The same applies to R ³² and R ^{33 in} the above formula (3), R ^{42 in} the above formula (4), and R ⁵² and R ⁵³ in the above formula (5).

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, the following diorganopolysiloxanes (1-1) to (1-23) are all terminal groups I (E ¹¹ : methyl group) having the structure represented by the above formula (14) as terminal groups, and the following formulas terminal group ^II having a structure represented by ^{(15) (E 12, R} 15 and ^{R 16:} methyl) having a.

  Among these, (1-1), (1-4), (1-5), (1-7), (1-10), (1-14) and (1-15) are preferable.

  The weight average molecular weight of the diorganopolysiloxane used in the present invention is preferably 1000 to 1000000, more preferably 10000 to 200000, particularly preferably 10000 to 100000, and more It is still more preferable that it is 20000-40000.

  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. If the fluorine atom content is less than 1% by mass, the releasability of the surface layer of the electrophotographic photosensitive member may not be sufficiently exhibited. If it exceeds 90% by mass, the binding in the surface layer of the electrophotographic photosensitive member may not be achieved. If the compatibility with the resin deteriorates or the anchor effect is not sufficiently obtained, it becomes easy to move to the surface, and if the surface of the electrophotographic photosensitive member is worn due to long-term durability use, a sufficient effect is obtained. It may not be possible.

  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.

On the other hand, the diorganopolysiloxane used in the present invention has an anchoring effect on the binder resin of the surface layer of the electrophotographic photoreceptor, particularly because the side chain D ¹¹ has an anchoring effect on the surface. It is suppressed.

  Hereinafter, the configuration of the electrophotographic photosensitive member used in the present invention will be described.

  The electrophotographic photoreceptor used in the present invention has a photosensitive layer on a support.

  The support may be anything that has conductivity (conductive support), and is provided with a metal support such as aluminum and stainless steel, or a layer that imparts conductivity on metal, paper, plastic, etc. And the like. Examples of the shape of the support include a cylindrical shape and a belt shape.

  The photosensitive layer is a single layer type in which the charge transport material and the charge generation material are contained in the same layer, but is separated into a charge generation layer containing the charge generation material and a charge transport layer containing the charge transport material. A mold (function separation type) may be used, but a laminated type is preferable from the viewpoint of electrophotographic characteristics. The laminated photosensitive layer has a normal layer type photosensitive layer laminated in the order of the charge generation layer and the charge transport layer from the support side, and a reverse layer type photosensitive layer laminated in the order of the charge transport layer and the charge generation layer from the support side. However, the normal layer type is preferable from the viewpoint of electrophotographic characteristics.

  When the exposure light is laser light, a conductive layer may be provided on the support for the purpose of preventing interference fringes due to scattering and for the purpose of covering scratches on the support. The conductive layer 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, and particularly preferably 10 to 30 μm. The interference fringes can also be prevented by treating the surface of the support by cutting treatment, alumite treatment, dry blast treatment, wet blast treatment or the like.

  An intermediate layer having an adhesive function or a barrier function may be provided on the support or the conductive layer. The intermediate layer is formed by dissolving a resin such as polyamide, polyvinyl alcohol, polyethylene oxide, ethyl cellulose, casein, polyurethane, and polyether urethane in an appropriate solvent, and applying and drying the solution on a support or a conductive layer. Can do. The thickness of the intermediate layer is preferably 0.05 to 5 μm, and particularly preferably 0.3 to 1 μm. Note that the intermediate layer is not necessarily required when the support surface is alumite-treated or when a sol-gel conductive film is used.

  When the photosensitive layer is a normal type photosensitive layer, a charge generation layer is provided on the support, the conductive layer, or the intermediate layer.

  Examples of the charge generation material include pigments such as selenium-tellurium, pyrylium, thiapyrylium dye, phthalocyanine, anthrone, dibenzpyrenequinone, trisazo, cyanine, azo (trisazo, disazo, monoazo), indigo, quinacridone, and asymmetric quinocyanine. Can be mentioned.

  The charge generation layer consists of a charge generation material, 0.3 to 4 times (mass ratio) binder resin and solvent, homogenizer, ultrasonic dispersion, ball mill, vibration ball mill, sand mill, attritor, roll mill, and liquid collision. It can be formed by sufficiently dispersing by a method such as a type high-speed disperser and applying and drying the resulting dispersion. Note that the binder resin may be added after the charge generating material is dispersed, or if the charge generating material has film-forming properties, the binder resin may not be used. The thickness of the charge generation layer is preferably 5 μm or less, and more preferably 0.1 to 2 μm.

  When the photosensitive layer is a normal type photosensitive layer, a charge transport layer is provided on the charge generation layer.

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

  The charge transport layer can be formed by dissolving the charge transport material and the binder resin with a solvent, and coating and drying the obtained coating solution. The charge transport layer is a surface layer of the electrophotographic photosensitive member. In this case, it can be formed by dissolving the charge transporting material and the binder resin, and the diorganopolysiloxane with a solvent, and coating and drying the obtained coating solution. The mass ratio of the charge transport material and the binder resin is preferably 5: 1 to 1: 5, and particularly preferably 3: 1 to 1: 3. The thickness of the charge transport layer is preferably 5 to 50 μm, and more preferably 10 to 30 μm.

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

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

Example 1
An aluminum cylinder (an alloy of JISA 3003 aluminum) having a length of 260.5 mm, a diameter of 30 mm, a cylinder portion thickness of 0.7 mm, a maximum surface roughness of 5.0 μm, and an average surface roughness of 1.0 μm was prepared.

  60 parts of powder consisting of barium sulfate particles having a tin oxide coating layer (trade name: Pastoran PC1, manufactured by Mitsui Mining & Smelting Co., Ltd.), 60 parts of titanium oxide (trade name: TITANIX JR, manufactured by Teika Co., Ltd.), 70 parts of resol type phenol resin (trade name: Phenolite J-325, manufactured by Dainippon Ink & Chemicals, Inc., solid content 70%), 10 parts of silicone oil (trade name: SH28PA, manufactured by Toray Silicone Co., Ltd.), A solution consisting of 10 parts of a silicone resin (trade name: Tospearl 120, manufactured by Toshiba Silicone Co., Ltd.), 60 parts of 2-methoxy-1-propanol and 60 parts of methanol was dispersed with a ball mill for about 20 hours.

  The conductive layer dispersion prepared in this manner was applied onto the above-mentioned aluminum cylinder by a dipping method, and was heat-cured at 140 ° C. for 30 minutes to form a resin layer having a thickness of 12 μm.

  Next, 10 parts of copolymerized polyamide resin (trade name: Amilan CM8000, manufactured by Toray Industries, Inc.) and 30 parts of methoxymethylated 6 nylon resin (trade name: Toresin EF-30T, manufactured by Teikoku Chemical Co., Ltd.) were added to methanol 400. A solution dissolved in a mixed solution of 200 parts by weight / n-butanol was dip-coated on the resin layer and dried by heating at 90 ° C. for 10 minutes to form a barrier layer having a thickness of 0.62 μm.

  Next, Bragg angles (2θ ± 0.2 °) of 7.5 °, 9.9 °, 16.3 °, 18.6 °, 25.1 ° and 28.3 ° in the characteristic X-ray diffraction of CuKα. 10 parts of crystalline hydroxygallium phthalocyanine having a strong peak and 5 parts of polyvinyl butyral resin (trade name: ESREC BX-1, manufactured by Sekisui Chemical Co., Ltd.) are added to 250 parts of cyclohexanone, and glass beads having a diameter of 1 mm are used. The mixture was dispersed for 1 hour in a conventional sand mill, diluted with 250 parts of ethyl acetate, and coated on the intermediate layer, and then dried at 100 ° C. for 10 minutes to form a charge generation layer having a thickness of 0.16 μm. Formed.

Next, the following materials were dissolved and adjusted to prepare a charge transport layer coating solution:
40 parts of charge transport material represented by the following formula (A)

下記式（Ｂ）で示される繰り返し構造単位を有するポリアリレート ５０部
（粘度平均分子量１０５０００）

50 parts of polyarylate having a repeating structural unit represented by the following formula (B) (viscosity average molecular weight 105000)

ジオルガノポリシロキサン ２．７部
（構造式（１−４） 重量平均分子量３６０００）
クロロベンゼン ３５０部
この電荷輸送層用塗工液を、上記電荷発生層上に浸漬塗布し、１２０℃で１時間加熱乾燥して、膜厚２０μｍの電荷輸送層を形成した。

2.7 parts of diorganopolysiloxane (Structural Formula (1-4) Weight Average Molecular Weight 36000)
Chlorobenzene 350 parts This charge transport layer coating solution was dip-coated on the charge generation layer and dried by heating at 120 ° C. for 1 hour to form a charge transport layer having a thickness of 20 μm.

Next, a charging roller was prepared by the following procedure:
Epichlorohydrin rubber terpolymer 100 parts (epichlorohydrin: ethylene oxide: allyl glycidyl ether = 40 mol%: 56 mol%: 4 mol%)
Light calcium carbonate 30 parts Aliphatic polyester plasticizer 10 parts Zinc stearate 1 part Anti-aging agent MB (2-mercaptobenzimidazole) 0.5 part Zinc oxide 5 parts Quaternary ammonium salt represented by the following formula 2 parts

以上の材料を５０℃に調節した密閉型ミキサーにて１０分間混練して、原料コンパウンドを調製した。このコンパウンドに原料のゴムのエピクロルヒドリンゴム１００部に対し、加硫剤としての硫黄１部、加硫促進剤としてのＤＭ（ジベンゾチアジルスルフィド）１部及びＴＳ（テトラメチルチウラムモノスルフィド）０．５部を加え、２０℃に冷却した２本ロール機にて１０分間混練した。得られたコンパウンドを、直径６ｍｍステンレス製の芯金に外径１５ｍｍのローラ状になるように押し出し成型機にて成型し、加熱蒸気加硫した後、外径が１２ｍｍになるように研磨加工を行い、弾性層を得た。ローラ長は２３２ｍｍとした。

The above materials were kneaded for 10 minutes in a closed mixer adjusted to 50 ° C. to prepare a raw material compound. For this compound, 100 parts of raw material epichlorohydrin rubber, 1 part of sulfur as a vulcanizing agent, 1 part of DM (dibenzothiazyl sulfide) as a vulcanization accelerator and 0.5 part of TS (tetramethylthiuram monosulfide) The mixture was added and kneaded for 10 minutes in a two-roll mill cooled to 20 ° C. The resulting compound is molded into a 6 mm stainless steel core with an extrusion molding machine to form a roller with an outer diameter of 15 mm, heated and steam vulcanized, and then polished to an outer diameter of 12 mm. And an elastic layer was obtained. The roller length was 232 mm.

  A surface layer 2d was formed on the elastic layer. The surface layer 2d was formed by coating the following surface layer coating solution by a dip coating method. The number of dip coatings was two.

First, as a coating for the surface layer, caprolactone-modified acrylic polyol solution 100 parts methyl isobutyl ketone 250 parts conductive tin oxide 130 parts (treated with trifluoropropyltrimethoxysilane, average particle size: 0.05 μm, volume resistivity: 10 ³ Ω・ Cm)
3 parts of hydrophobic silica (hexamethyldisilazane-treated product, average particle size: 0.012 μm, volume resistivity: 10 ¹⁶ Ω · cm)
Modified dimethyl silicone oil 0.08 parts Crosslinked PMMA particles 100 parts (average particle size: 4.51 μm, maximum particle size: 38.6 μm)
A mixed solution was prepared using a glass bottle as a container. The dispersion medium was filled with glass beads (average particle size: 0.8 mm) so that the filling rate was 80%, and dispersed for 8 hours using a paint shaker disperser. Add a mixture of hexamethylene diisocyanate (HDI) and isophorone diisocyanate (IPDI) butanone oxime block body 1: 1 to the dispersion so that NCO / OH = 1.0, and prepare a surface coating for dip coating. Prepared.

  The surface layer coating solution was coated twice on the surface of the elastic layer by a dip coating method, air-dried, and dried at a temperature of 160 ° C. for 1 hour.

<Measurement method of surface roughness>
About the produced charging member, 10-point average roughness (Rzjis) and average length (RSm) were measured using a surface roughness measuring machine SE-3400 manufactured by Kosaka Laboratory. The results are shown in Table 1.

<Measurement method of contact angle>
The contact angle was measured using pure water in an environment of normal temperature and normal humidity (25 ° C./50% RH), and the apparatus used was a contact angle meter CA-DS type manufactured by Kyowa Interface Science Co., Ltd. The contact angle was an average value of 5 points on the surface of the electrophotographic photosensitive member, and was measured within 1 minute after the water droplet was attached. The results are shown in Table 1.

<Measuring method of friction coefficient>
The dynamic friction coefficient (μ) on the surface of the electrophotographic photosensitive member is measured by using the cleaning blade fixing device shown in the schematic cross-sectional view of FIG. 6 in an environment of normal temperature and normal humidity (25 ° C./50% RH). Test apparatus (model HEIDON-14)} was used. This apparatus presses the blade 37 against the electrophotographic photosensitive member 36 with a constant load (g), and measures the force (g) applied when moving in parallel with the surface of the electrophotographic photosensitive member. The dynamic friction coefficient is obtained from the inclination of the graph of the force applied when moving with respect to the load applied to the blade by performing the same measurement while changing the load. The used blade was a urethane blade (rubber hardness 67 °) manufactured by Hokushin Kogyo Co., Ltd., cut into 5 mm × 30 mm × 2 mm, and measured with a width direction and an angle of 25 °. The results are shown in Table 1.

As an evaluation device, the Hewlett-Packard LBP “Laser Jet 4600” as shown in FIG. 1 was modified to operate at a process speed of 190 mm / sec, and the setting was changed to the following process conditions for evaluation. :
Electrophotographic photosensitive member dark part potential -400V
Electrophotographic photosensitive member bright part potential -170V
Development bias -350V (DC voltage only)

  For the evaluation, initial image evaluation was performed in an environment of low temperature and low humidity (15 ° C./10% RH). The image was evaluated visually by evaluating a charged streak image and a poorly cleaned image using a halftone test chart in which one dot was printed with a Keima pattern on the entire print surface and a solid black image. The results are shown in Table 1.

  Next, in a low-temperature and low-humidity environment (15 ° C./10% RH), a continuous image of 10,000 sheets was printed on the A4 size paper with a character pattern with an area ratio of 4%, and then the same method as the initial image evaluation Evaluation was carried out. The results are shown in Table 1.

(Example 2)
In Example 1, except that the amount of diorganopolysiloxane in the coating solution for the charge transport layer was changed from 2.7 parts to 9 parts, an electrophotographic photosensitive member was produced in the same manner as in Example 1 and evaluated. went. The evaluation results are shown in Table 1.

(Example 3)
In Example 1, the amount of diorganopolysiloxane in the coating solution for the charge transport layer was changed from 2.7 parts to 0.9 parts, and the PMMA particles added to the surface layer in the production of the charging roller had an average particle diameter of : 19.56 μm, maximum particle size: 130.5 μm, and electrophotographic photosensitive member and charging roller were prepared and evaluated in the same manner as in Example 1 except that the number of added parts was 20 parts. The evaluation results are shown in Table 1.

Example 4
In Example 1, the amount of diorganopolysiloxane in the coating solution for the charge transport layer was changed from 2.7 parts to 0.9 parts, and the PMMA particles added to the surface layer in the production of the charging roller had an average particle diameter of The electrophotographic photosensitive member and the charging roller were prepared and evaluated in the same manner as in Example 1 except that 9.85 μm, the maximum particle size: 52.5 μm, and the number of added parts were 60 parts. The evaluation results are shown in Table 1.

(Example 5)
In Example 1, except that the diorganopolysiloxane in the coating solution for the charge transport layer was changed from the structural formula (1-4) to the structural formula (1-15), the same as in Example 1. An electrophotographic photoreceptor was prepared and evaluated. The evaluation results are shown in Table 1.

(Example 6)
In Example 1, except that the diorganopolysiloxane in the coating solution for the charge transport layer was changed from that of the structural formula (1-4) to that of the structural formula (1-17), the same as in Example 1. An electrophotographic photoreceptor was prepared and evaluated. The evaluation results are shown in Table 1.

(Example 7)
In Example 1, except that the diorganopolysiloxane in the coating solution for the charge transport layer was changed from that of the structural formula (1-4) to that of the structural formula (1-1), the same as in Example 1. An electrophotographic photoreceptor was prepared and evaluated. The evaluation results are shown in Table 1.

(Comparative Example 1)
In Example 1, an electrophotographic photosensitive member and a charging roller were prepared and evaluated in the same manner as in Example 1 except that when the charging roller was prepared, no PMMA particles were added to the surface layer. The evaluation results are shown in Table 1.

(Comparative Example 2)
In Example 1, the PMMA particles added to the surface layer of the charging roller were the same as Example 1 except that the average particle size was 9.85 μm, the maximum particle size was 52.5 μm, and the number of added parts was 40 parts. An electrophotographic photosensitive member and a charging roller were prepared and evaluated. The evaluation results are shown in Table 1.

(Comparative Example 3)
In Example 1, PMMA particles added to the surface layer of the charging roller were the same as in Example 1 except that the average particle size was 19.65 μm, the maximum particle size was 130.5 μm, and the number of added parts was 60 parts. An electrophotographic photosensitive member and a charging roller were prepared and evaluated. The evaluation results are shown in Table 1.

(Comparative Example 4)
Example 1 except that 0.9 parts of a silicone-based graft polymer (trade name: GS-101CP: manufactured by Toagosei Co., Ltd.) was added in place of diorganopolysiloxane in the coating solution for charge transport layer in Example 1. In the same manner as above, an electrophotographic photosensitive member was produced and evaluated. The evaluation results are shown in Table 1.

(Comparative Example 5)
In Example 1, an electrophotographic photosensitive member was produced and evaluated in the same manner as in Example 1 except that the charge transport layer of the electrophotographic photosensitive member was formed as follows. The evaluation results are shown in Table 1.

  That is, 10 parts of a polyarylate resin (weight average molecular weight 128000) having a repeating structural unit represented by the above formula (B) is dissolved in 100 parts of chlorobenzene, and tetrafluoroethylene resin particles (trade name) as fluorine atom-containing resin particles. : Lubron L-2, manufactured by Daikin Industries, Ltd., average particle size (primary particle) 0.3 μm, average particle size (secondary particle) 5 μm) 10 parts and polymethyl methacrylate grafted with fluorine component (trade name) : Aron GF300, manufactured by Toagosei Co., Ltd.) was added and shaken well. This mixture was dispersed twice using a liquid-type disperser to prepare a fluorine atom-containing resin particle dispersion.

  Next, polyarylate resin having a repeating structural unit represented by the above formula (B): charge transport material (A): tetrafluoroethylene resin particle: polymethyl methacrylate grafted with the difluorine component: solvent The polyarylate resin having the repeating structural unit represented by the above formula (B) and the charge transporting material (A) such that (chlorobenzene) is 10: 8: 1: 1: 0.2: 80 in the final mass ratio. ) Was added to the fluorine atom-containing resin particle dispersion.

  This dispersion was dip coated on the charge generation layer and dried at 120 ° C. for 1 hour to form a charge transport layer having a thickness of 20 μm.

(Comparative Example 6)
In Example 1, an electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 1 except that diorganopolysiloxane (Structural Formula 1-4) was not added to the coating solution for the charge transport layer. It was. The evaluation results are shown in Table 1.

1 is a diagram showing a schematic configuration of an electrophotographic apparatus of the present invention. 1 is a diagram illustrating a schematic configuration of a full-color electrophotographic apparatus of the present invention. FIG. 3 is a cross-sectional view showing a configuration of a charging member used in the electrophotographic apparatus of the present invention. It is sectional drawing which shows the structure of the other charging member used for the electrophotographic apparatus of this invention. It is sectional drawing which shows the structure of the other charging member used for the electrophotographic apparatus of this invention. It is a schematic sectional drawing of the cleaning blade fixing device used for the measurement of the dynamic friction coefficient of the electrophotographic photoreceptor surface in an Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electrophotographic photoreceptor 2 Charging roller 2A Bias power supply 3 Exposure light 4 Developer 5 Charged particle (toner)
5a Transferable particle image (toner image)
5b Particles to be transferred 6 Transfer material 7 Transfer roller 7A Bias power supply 8 Cleaning device 9 Paper feed cassette 10 Paper feed roller 11 Registration rollers 20K, 20C, 20Y, 20M Process cartridges 21K, 21C, 21Y, 21M Electrophotographic photoreceptors 22K, 22C , 22Y, 22M Charging roller 23 Transfer roller 24 Conveyor belt 25 Laser light source 25 Toner 27 Fixing device 28 Feed roller 31 Support column 32 Holder support arm 33 Upper holder 34 Lower holder 35 Fixing screw 36 Sample 37 Urethane rubber blade

Claims (9)

An electrophotographic photoreceptor;
A charging member having a conductive elastic layer and a surface layer provided on the conductive elastic layer disposed in contact with the electrophotographic photosensitive member, and applying a voltage of only a DC voltage to the charging member; Charging means for charging the electrophotographic photoreceptor;
Exposure means for forming an electrostatic latent image on the surface of the electrophotographic photosensitive member by irradiating the surface of the electrophotographic photosensitive member charged by the charging means with exposure light;
Developing means for forming a toner image on the surface of the electrophotographic photosensitive member by developing an electrostatic latent image on the surface of the electrophotographic photosensitive member formed by the exposure means with toner;
Transfer means for transferring a toner image on the surface of the electrophotographic photosensitive member formed by the developing means to a transfer material;
Cleaning means for cleaning the surface of the electrophotographic photoreceptor by removing toner remaining on the surface of the electrophotographic photoreceptor after transfer by the transfer means;
In an electrophotographic apparatus comprising:
The contact angle of the surface of the electrophotographic photosensitive member with respect to pure water is 105 ° or more, and the dynamic friction coefficient is 0.6 or more and 1.2 or less,
The charging member has a ten-point average roughness (Rzjis) of 5.0 μm to 10.0 μm and an average length (RSm) of 10.0 μm to 70.0 μm. Electrophotographic device. A diorgano having a repeating structural unit α represented by the following formula (11) and a repeating structural unit β represented by the following formula (12) and having a weight average molecular weight of 1,000 to 1,000,000 on the surface layer of the electrophotographic photoreceptor. Polysiloxane is contained, and the content of the diorganopolysiloxane in the surface layer is 0.01 to 20% by mass with respect to the total mass of the surface layer (provided that the surface layer is fluorine atom-containing resin particles). 2) The electrophotographic apparatus according to claim 1:

(In formulas (11) and (12), R ¹¹ and R ¹² each independently represent a substituted or unsubstituted monovalent hydrocarbon group, and B ¹¹ is a monovalent organic group having a perfluoroalkyl group. D ¹¹ represents a monovalent organic group having a substituted or unsubstituted polystyrene chain having a degree of polymerization of 3 or more, a monovalent organic group having a substituted or unsubstituted alkyleneoxy group, and 12 carbon atoms. A monovalent group selected from the group consisting of the above monovalent organic groups). The electrophotographic apparatus according to claim 1, wherein the diorganopolysiloxane further has a repeating structural unit γ represented by the following formula (13):

(In formula (13), R ¹³ and R ¹⁴ each independently represents a substituted or unsubstituted monovalent hydrocarbon group).   The electrophotographic apparatus according to claim 1, wherein the diorganopolysiloxane has a weight average molecular weight of 10,000 to 200,000. The electrophotographic apparatus according to claim 1, wherein each of R ^{11 to} R ¹⁴ is independently a substituted or unsubstituted alkyl group or a substituted or unsubstituted phenyl group. The electrophotographic apparatus according to claim 1, wherein the monovalent organic group having a B ¹¹ perfluoroalkyl group is a monovalent group having a structure represented by the following formula (2):

(In formula (2), R ²¹ represents an alkylene group or an alkyleneoxyalkylene group, and a represents an integer of 3 or more). A monovalent organic group having a polymerization degree of 3 or more substituted or unsubstituted polystyrene chains of the D ¹¹ is, claim 1 is a monovalent group having a structure represented by the following formula (3) The electrophotographic apparatus described in:

(In formula (3), R ³¹ represents a substituted or unsubstituted divalent hydrocarbon group, and R ³² and R ³³ each independently represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group. W ³¹ represents a substituted or unsubstituted polystyrene chain having a degree of polymerization of 3 or more, R ³⁴ represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted aryl group, b is 0 or 1). A monovalent organic group having a substituted or unsubstituted alkyleneoxy group of the D ¹¹ is, electrons according to claim 1 which is a monovalent group having a structure represented by the following formula (4) Photo equipment:

(In formula (4), R ⁴¹ and R ⁴² each independently represents a substituted or unsubstituted divalent hydrocarbon group, and R ⁴³ represents a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group. C represents 0 or 1, and d represents an integer of 1 to 300. An electrophotographic photosensitive member and a charging means for charging the electrophotographic photosensitive member by applying only a direct current voltage to a charging member having at least an electroconductive elastic layer and a surface layer are integrally supported on the electrophotographic main body. In a process cartridge that is detachable,
The contact angle of the surface of the electrophotographic photosensitive member with respect to pure water is 105 ° or more, and the dynamic friction coefficient is 0.6 or more and 1.2 or less,
The charging member has a ten-point average roughness (Rzjis) of 5.0 μm to 10.0 μm and an average length (RSm) of 10.0 μm to 70.0 μm. Process cartridge.

Images