JP2019066708A - Image forming apparatus - Google Patents

Abstract

To provide an image forming apparatus that can exert high cleaning performance even at the initial stage of the start of use of a cleaning blade, and can prevent wear of the cleaning blade.SOLUTION: An image forming apparatus 100 of the present invention is an image forming apparatus comprising: photoreceptors 413; and cleaning units 415 each having a cleaning blade 10 that removes a residual toner on the photoreceptor 413. The photoreceptor 413 has an initial coefficient of dynamic friction of 0.3 or less, and the cleaning blade 10 is a plate-like elastic member and provided with a chamfer part 11 at an edge that rubs the surface of the photoreceptor 413.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an image forming apparatus. In particular, the present invention relates to an image forming apparatus capable of exhibiting high cleaning performance even at the beginning of use of a cleaning blade and suppressing abrasion of the cleaning blade.

  In recent years, with the increasing demand for high definition and high quality images in electrophotographic image forming apparatuses, it has become mainstream to use toner of small particle diameter, but toner of small particle diameter The adhesion to the surface of the photosensitive member (hereinafter also referred to as "photosensitive member") is large. For this reason, in order to achieve high cleaning performance, it is necessary to increase the contact pressure of the cleaning blade, which is a plate-like elastic member, to the photosensitive member, and as a result, the surface of the photosensitive member It may wear out.

  As a means for reducing the adhesion between the surface of the photosensitive member and the toner and enhancing the cleaning property, it is known to add a fluorinated material such as fluorinated fine particles or fluorinated lubricant to the protective layer of the photosensitive member. (See, for example, Patent Document 1).

  However, such a protective layer has a low coefficient of dynamic friction, and the edge of the cleaning blade is not worn but at a right angle at the beginning of use of the cleaning blade, so the contact between the cleaning blade and the photosensitive member is not complete. It becomes stable and stick slip may occur. For this reason, there is a problem that an image defect occurs due to the toner on the photosensitive member being not sufficiently removed or filming occurring at the initial stage of use of the cleaning blade. On the other hand, if the dynamic friction coefficient of the protective layer is increased, the abrasion of the cleaning blade is promoted.

Unexamined-Japanese-Patent No. 2010-197852

  The present invention has been made in view of the above problems and circumstances, and an object of the present invention is to provide an image forming apparatus capable of exhibiting high cleaning performance even at the initial stage of use of the cleaning blade and suppressing wear of the cleaning blade. It is to be.

In order to solve the above problems according to the present invention, as a result of examining the causes of the above problems and the like, an image forming comprising an electrophotographic photosensitive member and a cleaning unit having a cleaning blade for removing residual toner on the electrophotographic photosensitive member In the apparatus, the initial dynamic friction coefficient of the electrophotographic photosensitive member is 0.3 or less, the cleaning blade is a plate-like elastic member, and a chamfered portion is provided on the edge sliding on the surface of the electrophotographic photosensitive member. It has been found that the image forming apparatus can exhibit high cleaning performance even at the beginning of use of the cleaning blade and can suppress wear of the cleaning blade.
That is, the subject concerning the present invention is solved by the following means.

1. An image forming apparatus, comprising: an electrophotographic photosensitive member; and a cleaning unit having a cleaning blade for removing residual toner on the electrophotographic photosensitive member,
The initial dynamic friction coefficient of the electrophotographic photosensitive member is 0.3 or less,
2. The image forming apparatus according to claim 1, wherein the cleaning blade is a plate-like elastic member, and a chamfered portion is provided at an edge that slides on the surface of the electrophotographic photosensitive member.

2. The electrophotographic photosensitive member has a conductive support, a photosensitive layer disposed on the conductive support, and a protective layer disposed on the photosensitive layer,
The image forming apparatus according to claim 1, wherein the protective layer contains at least a polymerized and cured product of a composition containing a polymerizable monomer and a perfluoropolyether compound having a polymerizable group.

  3. The protective layer contains at least a polymerizable monomer, a first perfluoropolyether compound having 4 or more polymerizable groups, and a second perfluoropolyether compound having 0 to 3 polymerizable groups. The image forming apparatus according to claim 2, comprising a polymerized and cured product of the composition.

  4. The image forming apparatus according to claim 2 or 3, wherein the composition contains metal oxide particles.

  5. The image forming apparatus according to claim 4, wherein the metal oxide particles have a polymerizable group.

6. The chamfered portion is planar,
The image forming apparatus according to any one of claims 1 to 5, wherein a chamfering angle of the chamfered portion with respect to the thickness direction of the cleaning blade is in a range of 5 to 50 °.

7. The chamfered portion is planar,
The image forming apparatus according to any one of claims 1 to 6, wherein a length of the chamfered portion as viewed in an axial direction of the electrophotographic photosensitive member is 3 μm or more.

8. The chamfered portion is planar,
The image forming apparatus according to any one of claims 1 to 7, wherein a length of the chamfered portion as viewed in an axial direction of the electrophotographic photosensitive member is 15 μm or less.

9. The chamfered portion is curved,
The image forming apparatus according to any one of Items 1 to 5, wherein a radius of curvature of the chamfered portion is in a range of 5 to 15 μm.

  According to the present invention, it is possible to provide an image forming apparatus which can exhibit high cleaning performance even at the beginning of use of the cleaning blade and can suppress wear of the cleaning blade.

The mechanism for expressing the effects of the present invention or the mechanism of action is not clear but is presumed as follows.
The image forming apparatus of the present invention has a dynamic friction coefficient of 0.3 or less at the start of use of the electrophotographic photosensitive member and 0.3 or less, and the adhesion of the toner is reduced. Can reduce wear.
In addition, since the chamfered portion is provided on the edge of the cleaning blade that slides on the surface of the electrophotographic photosensitive member, the contact area between the cleaning blade and the surface of the electrophotographic photosensitive member can be secured. Thereby, even if the dynamic friction coefficient of the electrophotographic photosensitive member is a low value of 0.3 or less, the contact state of the cleaning blade with the electrophotographic photosensitive member, for example, the cleaning blade contacts the electrophotographic photosensitive member. The shape etc. after deformation can be stabilized, the occurrence of stick-slip can be suppressed, and high cleaning performance can be obtained from the beginning of use.

A schematic configuration diagram showing an example of the image forming apparatus of the present invention Schematic sectional view showing an example of a cleaning blade Schematic diagram showing another example of the cleaning blade

An image forming apparatus according to the present invention is an image forming apparatus including an electrophotographic photosensitive member and a cleaning unit having a cleaning blade for removing residual toner on the electrophotographic photosensitive member, and the initial stage of the electrophotographic photosensitive member The dynamic friction coefficient of the cleaning blade is 0.3 or less, and the cleaning blade is a plate-like elastic member, and a chamfered portion is provided on an edge sliding on the surface of the electrophotographic photosensitive member. This feature is a technical feature common to or corresponding to the following embodiments.
In the present invention, the electrophotographic photosensitive member has a conductive support, a photosensitive layer disposed on the conductive support, and a protective layer disposed on the photosensitive layer, and the protection It is preferable that the layer contains a polymerized and cured product of a composition containing at least a polymerizable monomer and a perfluoropolyether compound having a polymerizable group. Thereby, the influence of the discharge product in the protective layer can be suppressed, and high cleaning performance can be more reliably exhibited at the beginning of use of the cleaning blade.
Further, in the present invention, the protective layer includes at least a polymerizable monomer, a first perfluoropolyether compound having four or more polymerizable groups, and a second per group having 0 to 3 polymerizable groups. It is preferable to contain the polymerization hardening thing of the composition containing a fluoropolyether compound. Thus, high cleaning performance can be more reliably exhibited at the beginning of use of the cleaning blade, and wear of the cleaning blade can be further suppressed.
In the present invention, the composition preferably contains metal oxide particles. Thereby, the wear of the cleaning blade can be further suppressed.
Moreover, in the present invention, the metal oxide particles preferably have a polymerizable group. As a result, the hydroxyl groups on the surface of the metal oxide particles can be reduced, and further, since the detachment of the metal oxide particles from the protective layer can be suppressed, the cleanability can be improved.
Further, in the present invention, preferably, the chamfered portion is planar, and a chamfering angle of the chamfered portion with respect to the thickness direction of the cleaning blade is in a range of 5 to 50 °. Thus, high cleaning performance can be more reliably exhibited at the beginning of use of the cleaning blade, and abrasion of the cleaning blade can be further suppressed.
Further, in the present invention, it is preferable that the chamfered portion is flat and the length of the chamfered portion when viewed from the axial direction of the electrophotographic photosensitive member is 3 μm or more. Thus, high cleaning performance can be more reliably exhibited at the beginning of use of the cleaning blade, and abrasion of the cleaning blade can be further suppressed.
Further, in the present invention, it is preferable that the chamfered portion is flat and the length of the chamfered portion when viewed from the axial direction of the electrophotographic photosensitive member is 15 μm or less. Thus, high cleaning performance can be more reliably exhibited at the beginning of use of the cleaning blade, and abrasion of the cleaning blade can be further suppressed.
Further, in the present invention, it is preferable that the chamfered portion is a curved surface, and the radius of curvature of the chamfered portion is in the range of 5 to 15 μm. Thus, high cleaning performance can be more reliably exhibited at the beginning of use of the cleaning blade, and abrasion of the cleaning blade can be further suppressed.

  BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention, its components, and modes and modes for carrying out the present invention will be described in detail. In the present application, “to” is used in the meaning including the numerical values described before and after that as the lower limit value and the upper limit value.

<< Image forming device >>
An image forming apparatus according to the present invention is an image forming apparatus including an electrophotographic photosensitive member and a cleaning unit having a cleaning blade for removing residual toner on the electrophotographic photosensitive member, the initial dynamic friction of the electrophotographic photosensitive member The coefficient is 0.3 or less, and the cleaning blade is a plate-like elastic member, and a chamfered portion is provided at an edge rubbing the surface of the electrophotographic photosensitive member.

  For example, in the image forming apparatus according to the present invention, in addition to the photosensitive member and the cleaning unit, a charging unit that charges the surface of the photosensitive member, and an exposure unit that irradiates light to the surface of the charged photosensitive member to form an electrostatic latent image A developing unit for supplying a toner to a photosensitive member on which an electrostatic latent image is formed to form a toner image, a transferring unit for transferring a toner image on the surface of the photosensitive member to a recording medium, a toner image transferred on a recording medium A fixing unit and the like are provided. The image forming apparatus of the present invention will be described below with reference to FIG.

  FIG. 1 is a view schematically showing an example of the configuration of an image forming apparatus according to the present invention. An image forming apparatus 100 illustrated in FIG. 1 includes an image reading unit 110, an image processing unit 30, an image forming unit 40, a sheet conveyance unit 50, and a fixing device 60.

  The image forming unit 40 includes image forming units 41Y, 41M, 41C, and 41K that form images with toners of respective colors of Y (yellow), M (magenta), C (cyan), and K (black). Since all of these components have the same configuration except for the toner to be stored, symbols representing colors may be omitted hereinafter. The image forming unit 40 further includes an intermediate transfer unit 42 and a secondary transfer unit 43.

  The image forming unit 41 includes an exposure device 411, a developing device 412, a photosensitive member 413, a charging device 414, and a cleaning unit 415. The charging device 414 may be, for example, a contact charging device in which a contact charging member such as a charging roller, a charging brush, or a charging blade is brought into contact with the photosensitive member 413 for charging, or may be a corona discharge type charger. good. The exposure device 411 includes, for example, a semiconductor laser as a light source, and a light deflection device (polygon motor) that irradiates the photosensitive member 413 with a laser beam according to an image to be formed.

  The developing device 412 is, for example, a two-component developing type developing device. The developing device 412 includes, for example, a developing container for containing a two-component developer, a developing roller (magnetic roller) rotatably disposed at an opening of the developing container, and an inside of the developing container so that the two-component developer can communicate. It has partition walls separating, a conveying roller for conveying the two-component developer on the opening side of the developing container toward the developing roller, and a stirring roller for stirring the two-component developer in the developing container.

  The intermediate transfer unit 42 includes an intermediate transfer belt 421, a primary transfer roller 422 for pressing the intermediate transfer belt 421 against the photosensitive member 413, a plurality of support rollers 423 including a backup roller 423A, and a belt cleaning device 426. The intermediate transfer belt 421 is stretched around a plurality of support rollers 423 in a loop. By rotating at least one drive roller of the plurality of support rollers 423, the intermediate transfer belt 421 travels at a constant speed in the arrow A direction.

  The secondary transfer unit 43 has an endless secondary transfer belt 432 and a plurality of support rollers 431 including a secondary transfer roller 431A. The secondary transfer belt 432 is stretched in a loop by the secondary transfer roller 431A and the support roller 431. The secondary transfer roller 431A is in pressure contact with the backup roller 423A via the intermediate transfer belt 421 and the secondary transfer belt 432.

  The fixing device 60 covers, for example, the fixing roller 62 and the outer peripheral surface of the fixing roller 62, and heats and melts the toner forming the toner image on the sheet S, fixing the sheet S and the sheet S And a pressure roller 63 for pressing the roller 62 and the heat generating belt 61. The fixing device 60 heats and presses the sheet S by the heat generating belt 61 and the pressure roller 63.

  The image reading unit 110 includes a sheet feeding device 111 and a scanner 112. The sheet conveyance unit 50 includes a sheet feeding unit 51, a sheet discharge unit 52, and a conveyance path unit 53. In the three sheet feeding tray units 51a to 51c constituting the sheet feeding unit 51, sheets S (standard sheets, special sheets, etc.) identified based on basis weight, size, etc. are stored for each preset type. Ru. The conveyance path portion 53 has a plurality of conveyance roller pairs such as a registration roller pair 53a.

The formation of an image by the image forming apparatus 100 will be described.
The scanner 112 optically scans and reads the document D on the contact glass. Reflected light from the document D is read by the CCD sensor 112 a and becomes input image data. The input image data is subjected to predetermined image processing in the image processing unit 30 and sent to the exposure device 411.

  The photosensitive member 413 rotates at a constant circumferential speed. The charging device 414 uniformly charges the surface of the photosensitive member 413 to a negative polarity. In the exposure device 411, the polygon mirror of the polygon motor rotates at high speed, and the laser light corresponding to the input image data of each color component is developed along the axial direction of the photosensitive member 413, and the photosensitive member 413 along the axial direction. The outer peripheral surface of the Thus, an electrostatic latent image is formed on the surface of the photosensitive member 413.

  In the developing device 412, the toner particles are charged by stirring and transporting the two-component developer in the developing container, and the two-component developer is transported to the developing roller, and a magnetic brush is formed on the surface of the developing roller. The charged toner particles electrostatically adhere to the portion of the electrostatic latent image on the photosensitive member 413 from the magnetic brush. Thus, the electrostatic latent image on the surface of the photosensitive member 413 is visualized, and a toner image corresponding to the electrostatic latent image is formed on the surface of the photosensitive member 413. The toner image refers to a state in which toner is gathered in the form of an image.

  The toner image on the surface of the photosensitive member 413 is transferred to the intermediate transfer belt 421 by the intermediate transfer unit 42. Specifically, when the intermediate transfer belt 421 is in pressure contact with the photosensitive member 413 by the primary transfer roller 422, the toner images of the respective colors are sequentially overlapped and transferred onto the intermediate transfer belt 421. The transfer residual toner remaining on the surface of the photosensitive member 413 after transfer is removed by a cleaning unit 415 having a cleaning blade in sliding contact with the surface of the photosensitive member 413.

  On the other hand, the sheet S is conveyed by the sheet conveyance unit 50 to the nip portion between the intermediate transfer belt 421 and the secondary transfer belt 432. Correction of the inclination of the sheet S when passing through the nip portion and adjustment of the transport timing are performed by the registration roller pair 53a.

  When the sheet S is conveyed to the nip portion, a transfer bias is applied to the secondary transfer roller 431A. By the application of the transfer bias, the toner image carried on the intermediate transfer belt 421 is transferred to the sheet S. The sheet S on which the toner image has been transferred is conveyed by the secondary transfer belt 432 toward the fixing device 60.

  The toner image is fixed to the sheet S by applying heat and pressure by the fixing device 60. The sheet S on which the toner image is fixed is discharged to the outside of the machine by the paper discharge unit 52 provided with the paper discharge roller 52a.

  The transfer residual toner remaining on the surface of the intermediate transfer belt 421 after the secondary transfer is removed by a belt cleaning device 426 having a belt cleaning blade in sliding contact with the surface of the intermediate transfer belt 421.

<< Electrophotographic photosensitive member >>
The electrophotographic photosensitive member according to the present invention has an initial dynamic friction coefficient of 0.3 or less. Here, in the present invention, the initial stage of the electrophotographic photosensitive member refers to the attachment of the unit including the electrophotographic photosensitive member to the image forming apparatus main body.

The dynamic friction coefficient of the electrophotographic photosensitive member can be measured under the following conditions using an automatic roll friction and wear analyzer TSf-500R manufactured by KYOWA.
Contact member: Konica Minolta J paper 7 mm
Rotation speed: 100 rpm, 5 rot
External environment: 20 ° C, 50% RH
Load: 20g

  When the dynamic friction coefficient of the electrophotographic photosensitive member is 0.3 or less, the toner adhesion force is small, and the cleaning property can be improved. Further, since the frictional force between the surface of the electrophotographic photosensitive member and the cleaning blade is small, the load on the edge of the cleaning blade is small, and abrasion can be suppressed. From the viewpoint of suppressing the wear of the cleaning blade, the dynamic friction coefficient of the electrophotographic photosensitive member is preferably 0.24 or less.

  Further, the electrophotographic photosensitive member according to the present invention is configured to have a conductive support, a photosensitive layer disposed on the conductive support, and a protective layer disposed on the photosensitive layer. Is preferred. In this case, the surface of the protective layer needs to satisfy the dynamic friction coefficient of 0.3 or less.

  The conductive support is a member capable of supporting the photosensitive layer and having conductivity. As the conductive support, for example, a drum or sheet made of metal, a plastic film having a laminated metal foil, a plastic film having a film of a deposited conductive substance, a conductive substance or a paint comprising the same and a binder resin And a metal member having a conductive layer formed by applying the above, a plastic film, paper and the like. As a metal used here, aluminum, copper, chromium, nickel, zinc, stainless steel etc. are mentioned, for example, As said electroconductive substance, the said metal, an indium oxide, a tin oxide is mentioned, for example.

  The photosensitive layer is a layer for forming an electrostatic latent image of a desired image on the surface of the photoreceptor by the exposure. The photosensitive layer may be constituted of a single layer or may be constituted by laminating a plurality of layers. For example, a single layer structure containing a charge transporting compound and a charge generating compound, a laminated structure of a charge transporting layer containing a charge transporting compound, and a charge generating layer containing a charge generating compound may be mentioned.

  In addition, the photosensitive member may further include other components other than the conductive support, the photosensitive layer, and the protective layer, as long as the effects according to the present embodiment can be obtained. The other configuration includes, for example, an intermediate layer disposed between the conductive support and the photosensitive layer and having a barrier function and an adhesive function.

  Each member other than the protective layer constituting the photosensitive member can be configured in the same manner as a known organic photosensitive member.

<< Protective layer >>
The protective layer is a layer for protecting the photosensitive layer which is disposed on the photosensitive layer and which constitutes the surface of the photosensitive member.

  The protective layer is composed of a polymerized and cured product of a composition containing a polymerizable monomer, a polymerizable perfluoropolyether compound, etc. from the viewpoint of adjusting the initial dynamic friction coefficient of the electrophotographic photosensitive member to 0.3 or less more easily. Is preferred. Further, the composition more preferably contains metal oxide particles, and the metal oxide particles further preferably have a polymerizable group. Thus, the protective layer is composed of an integral polymer formed by polymerization of a polymerizable monomer, and a perfluoropolyether component, metal oxide particles and the like are dispersed therein. Moreover, the said perfluoro polyether component, metal oxide particle, etc. can be couple | bonded with the said polymer by the covalent bond by a polymerization reaction.

  These polymerizable monomers, polymerizable perfluoropolyether compounds and metal oxide particles may be used singly or in combination of two or more.

  Hereinafter, materials for forming the protective layer will be described in detail.

[Polymerizable monomer]
The polymerizable monomer according to the present invention has a polymerizable group, and is polymerized (cured) by irradiation of actinic radiation such as ultraviolet light, visible light and electron beam, or by addition of energy such as heating, and in general, a photosensitive member And a compound to be used as a binder resin of In addition, the polymerizable perfluoropolyether compound is not included in the polymerizable monomer in the present application.
The polymerizable monomer is preferably a radical polymerizable monomer that cures via a radical polymerization reaction. Examples of the polymerizable monomer include styrene-based monomers, acrylic-based monomers, methacrylic-based monomers, vinyl toluene-based monomers, vinyl acetate-based monomers, N-vinyl pyrrolidone-based monomers and the like, and binder resins include, for example, polystyrene, Polyacrylate etc. are mentioned.

The polymerizable group contained in the polymerizable monomer has a carbon-carbon double bond and is a polymerizable group. The polymerizable group is particularly preferably an acryloyl group (CH ₂ CHCHCO—) or a methacryloyl group (CH ₂ CC (CH ₃ ) CO—) because curing with a small amount of light or a short time is possible. .

  Specific examples of the polymerizable monomer include, but are not limited to, the following compounds M1 to M11. In each of the following formulas, R represents an acryloyl group, and R 'represents a methacryloyl group.

The above polymerizable monomers can be synthesized by known methods, and can also be obtained as commercial products.
Moreover, as a polymerizable monomer, it is preferable that it is a compound which has 3 or more of polymerizable groups from a viewpoint of forming a high hardness protective layer with high crosslinking density.

[Perfluoropolyether compound having a polymerizable group]
A perfluoropolyether (PFPE) compound is an oligomer or polymer having a perfluoroalkylene ether as a repeating unit. As a repeating unit of perfluoro alkylene ether, repeating units, such as perfluoro methylene ether, perfluoro ethylene ether, perfluoro propylene ether, etc. are mentioned, for example. Among them, the polymerizable perfluoropolyether compound preferably has a repeating unit represented by the following formula (a) or a repeating unit represented by the following formula (b).

  When the PFPE compound has a repeating unit represented by the above formula (a) or (b), the repeating number m of the repeating unit represented by the formula (a) and the repeating unit represented by the formula (b) Repetition numbers n are each independently an integer of 0 or more, and m + n ≧ 5. m is preferably 2 to 20, and more preferably 2 to 15. In addition, n is preferably 2 to 20, and more preferably 2 to 15.

  Moreover, when it has both the repeating unit represented by said Formula (a), and the repeating unit represented by said Formula (b), those 2 types of repeating units form the block copolymer structure. It may be a random copolymer structure.

  The weight average molecular weight Mw of the PFPE compound according to the present invention is preferably in the range of 100 to 8000, and more preferably in the range of 500 to 5000. The weight average molecular weight Mw can be determined, for example, by a known method using gel permeation chromatography (GPC).

  The number of polymerizable groups contained in the PFPE compound according to the present invention is 1 or more, preferably 2 or more. Two or more polymerizable groups may be substituted at one end or both ends of the PFPE compound.

  Among them, the PFPE compound having four or more polymerizable groups has more reaction points with the above-mentioned polymerizable monomer and metal oxide particles described later. Therefore, it is particularly preferable from the viewpoint of enhancing the abrasion resistance and the cleaning property of the photosensitive member.

  The polymerizable group contained in the PFPE compound according to the present invention is a polymerizable group having a carbon-carbon double bond, as in the polymerizable group of the polymerizable monomer. The polymerizable group is particularly preferably, for example, an acryloyl group or a methacryloyl group. The polymerizable group contained in the PFPE compound may be the same as or different from the polymerizable group contained in the polymerizable monomer. When the PFPE compounds have a plurality of polymerizable groups, they may be the same as or different from each other.

  As PFPE compounds having an acryloyl group or a methacryloyl group, for example, Fluorolink AD1700, MD500, MD700, 5101X, 5113X, Fomblin MT70 ("FLUOROLINK" and "FOMBLIN" are all registered trademarks of the company) manufactured by Solvay Specialty Polymers. And OPTOOL DAC manufactured by Daikin Industries, Ltd., KY-1203 manufactured by Shin-Etsu Chemical Co., Ltd., and the like.

In addition, a PFPE compound having a polymerizable group can be appropriately synthesized using a PFPE compound having a hydroxy group or a carboxy group at a terminal as a raw material, and such a synthesized product may be used.
Examples of PFPE compounds having a hydroxy group at the end include Fomblin D2 manufactured by Solvay Specialty Polymers, Fluorolink D4000, Fluorolink E10H, 5158X, 5147X, Fomblin Z DOL, Fomblin Z-tet-raol, Demnum manufactured by Daikin Industries, Ltd. -SA etc. are mentioned. Examples of PFPE compounds having a carboxy group at the end include Fomblin ZDIZAC4000 manufactured by Solvay Specialty Polymers, and Demnum-SH manufactured by Daikin Industries, Ltd.

  The content of the PFPE compound having a polymerizable group in the composition for forming the protective layer is, for example, 10 parts by mass with respect to 100 parts by mass of the polymerizable monomer from the viewpoint of sufficiently exhibiting the cleaning property of the photoreceptor. The amount is preferably at least part, and more preferably at least 20 parts by mass. The content of the PFPE compound having a polymerizable group in the composition for forming the protective layer is, for example, 100 parts by mass of a polymerizable monomer from the viewpoint of sufficiently developing the abrasion resistance and the scratch resistance of the photosensitive member. The amount is preferably 100 parts by mass or less, and more preferably 70 parts by mass or less.

(First PFPE compound)
The first PFPE compound is a PFPE compound having four or more polymerizable groups. When the composition for forming the protective layer contains the first PFPE compound, the bonding site of the PFPE compound with the polymerizable monomer and the like is increased, and protection with high wear resistance and higher cleaning property is maintained. Layers can be formed.

  The first PFPE compound preferably has a structure represented by the following general formula (1).

  In the above general formula (1), A represents a (q + 1) -valent linking group, which may be identical to or different from each other. X represents a polymerizable group, which may be identical to or different from each other. m and n each independently represent an integer of 0 or more, and m + n ≧ 5. q represents an integer of 2 or more and may be the same as or different from each other.

  In the general formula (1), the linking group represented by A is preferably independently in the range of 100 to 400 in molecular weight. By being in the range of 100 to 400, the first PFPE compound has sufficient compatibility with the polymerizable monomer, and as a result, the first PFPE in the composition for forming the protective layer The compound can be sufficiently added and the first PFPE compound can be well dispersed.

  In the general formula (1), the molecular weight of the linking group represented by A is, for example, a known molecular weight measurement of the first PFPE compound by GPC or a known analytical technique such as nuclear magnetic resonance (NMR) It can be determined by the method of

  In the general formula (1), the linking group represented by A may be an organic group having a predetermined molecular weight, and examples thereof include a trivalent or higher organic group containing an ester bond or a urethane bond.

  The polymerizable group represented by X in the general formula (1) has a carbon-carbon double bond and is a polymerizable group, similarly to the polymerizable group possessed by the polymerizable monomer. The polymerizable group contained in the first PFPE compound may be the same as or different from the polymerizable group contained in the polymerizable monomer, and examples thereof include an acryloyloxy group and a methacryloyloxy group. .

  In the general formula (1), since q independently represents an integer of 2 or more, the number of polymerizable groups contained in the first PFPE compound is 4 or more. When the number of polymerizable groups is 4 or more, sufficient film strength of the protective layer can be obtained. In addition, from the viewpoint of easily synthesizing the first PFPE compound, the molecular structure of the first PFPE compound preferably has symmetry, so the number of polymerizable groups is preferably an even number.

The first PFPE compound can be appropriately synthesized by substitution of these substituents or derivation from these substituents, using the PFPE compound having a hydroxy group or a carboxy group at the end as a raw material, as described above. Examples of the method of synthesizing the first PFPE compound include the following methods (1) to (3).
(1) A method of subjecting a PFPE compound having a hydroxy group at an end to an esterification reaction of (meth) acrylic acid chloride by dehydrochlorination.
(2) A method in which an isocyanate compound having a (meth) acryloyl group is subjected to a urethanization reaction with a PFPE compound having a hydroxyl group at an end.
(3) A method in which a PFPE compound having a carboxy group at the end is converted to an acid halide by a conventional method, and an esterification reaction is performed on the acid halide with a compound having a (meth) acryloyl group and a hydroxy group.

  Specific examples of the first PFPE compound are shown below, but are not limited thereto. Among the following compounds, PFPE-A-1 to PFPE-A-9 all have a structure represented by the above general formula (1). In each of the following formulas, X represents an acryloyloxy group or a methacryloyloxy group, m and n each independently represent an integer of 0 or more, and m + n ≧ 5.

(Second PFPE compound)
The second PFPE compound has the same structure as the first PFPE compound except that the number of polymerizable groups is different. The second PFPE compound has 0 to 3 polymerizable groups. When the number of polymerizable groups is two or three, the polymerizable group may be bonded to one end, or may be bonded to both ends.

  When the number of polymerizable groups in the second PFPE compound is 0 to 3, the PFPE compound can move in the protective layer, and the high cleanability of the protective layer can be maintained for a long time.

  The polymerizable group of the second PFPE compound has a carbon-carbon double bond and is polymerizable. As the said polymeric group, acryloyloxy group, methacryloyloxy group etc. are preferable, for example.

  The second PFPE compound having zero number of polymerizable groups is subjected to pyrolysis GC-MS, nuclear magnetic resonance (NMR), Fourier transform infrared spectrophotometer (FT-IR), and solvent-soluble components extracted from the protective layer. And can be confirmed by analysis using known instrumental analysis techniques such as elemental analysis.

  As the second PFPE compound, as described above, a commercially available product may be used, or a PFPE compound having a hydroxy group or a carboxy group at an end may be appropriately synthesized as a material.

  Specific examples of the second PFPE compound are shown below, but are not limited thereto. In each of the following formulas, X represents an acryloyloxy group or a methacryloyloxy group, m and n each independently represent an integer of 0 or more, and m + n ≧ 5. Moreover, in the following formula, p represents an integer of 1 or more.

[Metal oxide particles]
The composition for forming the protective layer according to the present invention preferably contains metal oxide particles, and the metal oxide particles preferably have a polymerizable group. The polymerizable group has a carbon-carbon double bond and is a polymerizable group. The polymerizable group which may be possessed by the metal oxide particles may be one kind or more and may be the same or different from each other, and the polymerizable group which the above-mentioned polymerizable monomer or PFPE compound has and It may be the same or different.

  The metal oxide particles having a polymerizable group (hereinafter, also referred to as polymerizable metal oxide particles) are metal oxide particles having a component containing a polymerizable group supported on the surface. The support of the component containing the polymerizable group on the surface of the metal oxide particles may be physical support or may be chemical bonding. The polymerizable metal oxide particles have, for example, metal oxide particles, a surface modifier residue chemically bonded to the surface, and the above-mentioned polymerizable group contained in the surface modifier residue, and are protected. In the layer, the metal oxide particles are present in a state of being chemically bonded to the integral polymer constituting the protective layer via the surface modifier residue possessed on the surface thereof. The surface modifier residue is, for example, a molecular structure chemically bonded to the surface of the metal oxide particle, and is a portion derived from the surface modifier.

The metals constituting the metal oxide particles also include transition metals. As a metal oxide in metal oxide particles, for example, silica (silicon oxide), magnesium oxide, zinc oxide, lead oxide, alumina (aluminum oxide), tin oxide, tantalum oxide, indium oxide, bismuth oxide, yttrium oxide, oxide Cobalt, copper oxide, manganese oxide, selenium oxide, iron oxide, zirconium oxide, germanium oxide, tin oxide, titanium dioxide, titanium dioxide, niobium oxide, molybdenum oxide, vanadium oxide and copper aluminum oxide can be mentioned. Among them, alumina (Al ₂ O ₃ ), tin oxide (SnO ₂ ), titanium dioxide (TiO ₂ ) and copper-aluminum complex oxide (CuAlO ₂ ) are preferable. Further, silica is preferably a metal oxide other than silica from the viewpoint of suppression of image blurring and the like because there are many hydroxy groups present on the particle surface.
The metal oxide particles contained in the composition for forming the protective layer may be one or more, and may be the same or different.

  The number average primary particle size of the metal oxide particles is, for example, preferably in the range of 1 to 300 nm, and particularly preferably in the range of 3 to 100 nm. The number average primary particle size of the metal oxide particles may be a catalog value, but can be determined as follows. That is, a 10000 × magnified image taken with a scanning electron microscope (manufactured by Nippon Denshi Co., Ltd.) is taken into a scanner, and 300 particle images excluding aggregated particles are automatically subjected to random image processing from the obtained photographic image. Analysis system "Lusex AP" (Nireko Co., Ltd., "LUZEX" is a registered trademark of the company, software Ver.1.32) is binarized using the respective horizontal direction Feret diameter of the particle image is calculated The average value is calculated to obtain the number average primary particle diameter. Here, the Feret diameter in the horizontal direction refers to the length of the side of the circumscribed rectangle when the particle image is binarized and parallel to the x-axis.

  The loading of the component containing the polymerizable group onto the surface of the metal oxide particles can be carried out by known surface treatment techniques for metal oxide particles.

  The surface modifying agent has a polymerizable group and a surface modifying group. The said surface modification group is a functional group which has the reactivity to polar groups, such as a hydroxyl group, etc. which are present on the surface of metal oxide particles. As a polymeric group, a vinyl group, an acryl group, methacryl group etc. are mentioned, for example. The surface modifiers may be used alone or in combination of two or more.

  Moreover, it is preferable that it is a silane coupling agent which has a polymeric group, for example, for example, although following compound S-1-S-31 are mentioned, for example, it is not limited to these.

_{S-1: CH 2 = CHSi} (CH 3) (OCH 3) 2
_{S-2: CH 2 = CHSi} (OCH 3) 3
S-3: CH ₂ = CHSiCl ₃
S-4: CH ₂ CHCHCOO (CH ₂ ) ₂ Si (CH ₃ ) (OCH ₃ ) _{2
S-5: CH 2 = CHCOO} (CH 2) 2 Si (OCH 3) 3
S-6: CH ₂ = CHCOO (CH ₂ ) ₂ Si (OC ₂ H ₅ ) (OCH ₃ ) ₂
S-7: CH ₂ = CHCOO (CH ₂ ) ₃ Si (OCH ₃ ) ₃
S-8: CH ₂ = CHCOO (CH ₂ ) ₂ Si (CH ₃ ) Cl _{2
S-9: CH 2 = CHCOO} (CH 2) 2 SiCl 3
_{S-10: CH 2 = CHCOO} (CH 2) 3 Si (CH 3) Cl 2
_{S-11: CH 2 = CHCOO} (CH 2) 3 SiCl 3
_{S-12: CH 2 = C} (CH 3) COO (CH 2) 2 Si (CH 3) (OCH 3) 2
_{S-13: CH 2 = C} (CH 3) COO (CH 2) 2 Si (OCH 3) 3
S-14: CH ₂ CC (CH ₃ ) COO (CH ₂ ) ₃ Si (CH ₃ ) (OCH ₃ ) ₂
S-15: CH ₂ CC (CH ₃ ) COO (CH ₂ ) ₃ Si (OCH ₃ ) ₃
S-16: CH ₂ CC (CH ₃ ) COO (CH ₂ ) ₂ Si (CH ₃ ) Cl _{2
S-17: CH 2 = C} (CH 3) COO (CH 2) 2 SiCl 3
_{S-18: CH 2 = C} (CH 3) COO (CH 2) 3 Si (CH 3) Cl 2
S-19: CH ₂ CC (CH ₃ ) COO (CH ₂ ) ₃ SiCl _{3
S-20: CH 2 = CHSi} (C 2 H 5) (OCH 3) 2
_{S-21: CH 2 = C} (CH 3) Si (OCH 3) 3
_{S-22: CH 2 = C} (CH 3) Si (OC 2 H 5) 3
_{S-23: CH 2 = CHSi} (OCH 3) 3
S-24: CH ₂ CC (CH ₃ ) Si (CH ₃ ) (OCH ₃ ) _{2
S-25: CH 2 = CHSi} (CH 3) Cl 2
_{S-26: CH 2 = CHCOOSi} (OCH 3) 3
_{S-27: CH 2 = CHCOOSi} (OC 2 H 5) 3
S-28: CH ₂ CC (CH ₃ ) COOSi (OCH ₃ ) ₃
S-29: CH ₂ = C (CH ₃ ) COOSi (OC ₂ H ₅ ) _{3
S-30: CH 2 = C} (CH 3) COO (CH 2) 3 Si (OC 2 H 5) 3
_{S-31: CH 2 = CHCOO} (CH 2) 2 Si (CH 3) 2 (OCH 3)

  The addition amount of the polymerizable metal oxide particles in the composition for forming the protective layer is sufficient to develop the mechanical strength of the protective layer and to realize appropriate electric resistance, the polymerizable monomer and the PFPE It is preferable that it is 30 mass parts or more with respect to a total of 100 mass parts with a compound. Moreover, it is preferable that it is 100 mass parts or less from a viewpoint of fully exhibiting cleaning property.

<< Production method of electrophotographic photosensitive member >>
The electrophotographic photosensitive member according to the present invention can be produced by a known method for producing a photosensitive member except that the above composition is used as a coating solution for forming a protective layer. For example, the step of applying a coating solution for forming a protective layer containing the above composition on the surface of a photosensitive layer formed on a conductive support, and irradiation or heating of the formed coating film with actinic radiation And polymerizing the composition.

  The coating liquid for forming a protective layer may further contain other components other than the above composition, as long as the effects of the present embodiment can be obtained. As the said other component, a solvent and a polymerization initiator are mentioned, for example.

  Examples of the solvent contained in the coating solution for forming a protective layer include methanol, ethanol, n-propyl alcohol, isopropyl alcohol, n-butanol, t-butanol, sec-butanol, benzyl alcohol, toluene, xylene, methyl ethyl ketone, cyclohexane Ethyl acetate, butyl acetate, methyl cellosolve, ethyl cellosolve, tetrahydrofuran, 1,3-dioxane, 1,3-dioxolane, pyridine and diethylamine. A solvent may be used individually by 1 type, and 2 or more types may be mixed and used.

  The polymerization initiator contained in the coating liquid for protective layer formation can be suitably selected and used from well-known polymerization initiators according to the formation process of a protective layer. Examples of the polymerization initiator include a photopolymerization initiator, a thermal polymerization initiator, and a polymerization initiator capable of initiating polymerization with both light and heat. The polymerization initiator may be used singly or in combination of two or more.

  Further, a photopolymerization accelerator having a photopolymerization promoting effect may be used in combination with the photopolymerization initiator. Examples of the photopolymerization accelerator include triethanolamine, methyldiethanolamine, ethyl 4-dimethylaminobenzoate, isoamyl 4-dimethylaminobenzoate, ethyl (2-dimethylamino) benzoate and 4,4'-dimethylamino Benzophenone is mentioned.

  The polymerization initiator contained in the coating solution for forming a protective layer is preferably a photopolymerization initiator, for example, an alkylphenone compound or a phosphine oxide compound, and a polymerization initiation having an α-hydroxyacetophenone structure. An agent or a polymerization initiator having an acyl phosphine oxide structure is more preferable.

  The content of the polymerization initiator in the composition for forming the protective layer is preferably in the range of 0.1 to 40 parts by mass, more preferably 0.5 based on 100 parts by mass of the polymerizable monomer. It is in the range of -20 mass parts.

  In the protective layer, the polymerizable monomer, the PFPE compound having a polymerizable group, and the polymerizable metal oxide particles constitute an integral polymerized and cured product that forms the protective layer. The fact that the cured product is a polymerizable monomer, a PFPE compound having a polymerizability, and a polymer of a polymerizable metal oxide particle has thermal decomposition GC-MS, nuclear magnetic resonance (NMR), Fourier transform infrared spectroscopy It is possible to confirm by analysis of the said polymerization hardening thing by well-known instrumental analysis techniques, such as total (FT-IR) and elemental analysis.

  The polymerizable monomer, the PFPE compound having a polymerizable group, and the polymerizable metal oxide particles all have a polymerizable group. Therefore, in the composition for forming the protective layer, these components have high compatibility with each other. Therefore, the PFPE component and the metal oxide particles are both uniformly dispersed in the composition, and are present in the protective layer in a uniformly dispersed state in both the surface direction and the layer thickness direction.

  In the protective layer, the polymerizable monomer, the PFPE compound having a polymerizable group, and the polymerizable groups of the polymerizable metal oxide particles react with each other to form a crosslinked structure. Therefore, even if the content of the PFPE component is relatively high, a high-strength protective layer having sufficient abrasion resistance can be formed.

  In addition, since the PFPE component and the metal oxide particles are uniformly dispersed in the surface direction and the layer thickness direction of the protective layer in the protective layer, high cleanability is maintained even if the surface of the protective layer is worn away. A sufficient amount of PFPE component is present in the protective layer to Thereby, high cleanability is maintained for a long time.

Cleaning blade
The cleaning unit according to the present invention brings the cleaning blade into contact with the electrophotographic photosensitive member to remove the residual toner on the electrophotographic photosensitive member. Further, the cleaning blade is a plate-like elastic member, and a chamfered portion is provided on an edge that slides on the surface of the electrophotographic photosensitive member.

  The cleaning blade is attached to and supported by a housing of the cleaning unit directly or through a holder or the like. Further, the cleaning blade is disposed such that its longitudinal direction is parallel to the axial direction of the photosensitive member.

  The material of the cleaning blade is preferably one having a high impact resilience, so that it can follow the eccentricity of the photosensitive member, the micro waviness of the photosensitive member surface, etc. For example, urethane rubber which is a rubber containing a urethane group preferable.

  Further, as the hardness of the cleaning blade, for example, the hardness at 25 ° C. is preferably in the range of 68 to 80 degrees (JIS A). Sufficient flexibility is obtained when the angle is 80 degrees or less, and, for example, when the cleaning blade is attached to the cleaning portion with a slight inclination, the contact pressure at one end side and the other end side in the longitudinal direction of the cleaning blade The occurrence of different so-called bias can be suppressed more reliably. Thus, the cleaning blade can be brought into contact with the photosensitive member with a more uniform contact pressure in the longitudinal direction, and the cleaning performance can be improved. Even if the contact pressure of the cleaning blade with respect to the photosensitive member is high, the curvature of the cleaning blade can be suppressed, and the floating of the edge can be more reliably suppressed. As a result, the contact area between the cleaning blade and the photosensitive member can be adjusted to an appropriate value, and the cleaning performance can be improved.

  Here, an example of the cleaning blade according to the present invention will be described with reference to FIGS. 2 and 3. FIG. 2 is a schematic view of the cleaning blade 10 as viewed from the axial direction of the photosensitive member 413. As shown in FIG. FIG. 3 is a schematic view of the cleaning blade 20 as viewed from the axial direction of the photosensitive member 413. As shown in FIG. In FIGS. 2 and 3, the cleaning blades 10 and 20 are illustrated as being separated from the photosensitive member 413, but when the cleaning operation is performed, the cleaning blades 10 and 20 abut the photosensitive member 413 with a predetermined pressure.

  As shown in FIG. 2, in the cleaning blade 10, a flat chamfered portion 11 is provided at an edge on which the photosensitive member 413 is rubbed.

  The chamfered portion 11 is formed by removing an edge portion shown by a two-dot chain line in FIG. As a method of removing the edge portion, polishing may be used, or the edge portion may be removed. The polishing process can be performed, for example, using a precision polishing member having a small particle size. The grain size of the polishing member to be used is preferably 3 μm or less from the viewpoint of the smoothness of the chamfered portion 11 to be formed.

The chamfering angle θ of the chamfered portion 11 with respect to the thickness direction of the cleaning blade 10 is preferably in the range of 5 to 50 °.
If the chamfering angle θ is 5 ° or more, the effect of providing the chamfered portion 11 is sufficiently obtained, and the contact state of the cleaning blade with the photosensitive member can be further stabilized. When the chamfering angle θ is 50 ° or less, a sufficient scraping force (peak pressure) required for cleaning can be secured. Further, when the chamfering angle θ is 50 ° or less, the toner scraped off at the time of cleaning is easily discharged as waste toner, and the toner fluid layer generated around the stationary cleaning layer is reduced, thereby reducing the amount of abrasion of the cleaning blade. be able to. Accordingly, when the chamfering angle θ is in the above range, high cleaning performance can be more reliably exhibited from the beginning of use, and wear of the cleaning blade can be further suppressed.

The length L of the chamfered portion 11 as viewed in the axial direction of the photosensitive member 413 (longitudinal direction of the cleaning blade 10) is preferably 3 μm or more, and more preferably 15 μm or less.
When the length L is 3 μm or more, the effect of providing the chamfered portion 11 is sufficiently obtained, and the contact state of the cleaning blade with the photosensitive member can be further stabilized. When the length L is 15 μm or less, sufficient scraping force (peak pressure) required for cleaning can be secured. In addition, when the length L is 15 μm or less, the toner scraped off at the time of cleaning is easily discharged as waste toner, and the toner flow layer generated around the stationary cleaning layer is reduced, so that the amount of abrasion of the cleaning blade is reduced. Can. Therefore, when the length L is in the above range, high cleanability can be more reliably exhibited from the beginning of use, and wear of the cleaning blade can be further suppressed.

Here, the cleaning unit may have a cleaning blade 20 shown in FIG.
As shown in FIG. 3, in the cleaning blade 20, a curved chamfered portion 21 is provided at an edge on which the photosensitive member 413 is rubbed.

Further, the radius of curvature of the chamfered portion 21 is preferably in the range of 5 to 15 μm.
When the radius of curvature is 5 μm or more, the effect of providing the chamfered portion 21 is sufficiently obtained, and the contact state of the cleaning blade with the photosensitive member can be further stabilized. When the radius of curvature is 15 μm or less, the scraping force (peak pressure) required for cleaning can be sufficiently secured. In addition, when the radius of curvature is 15 μm or less, the toner scraped off at the time of cleaning is easily discharged as waste toner, and the toner fluid layer generated around the stationary cleaning layer is reduced, so that the amount of abrasion of the cleaning blade can be reduced. it can. Therefore, when the radius of curvature is in the above range, high cleanability can be more reliably exhibited from the beginning of use, and wear of the cleaning blade can be further suppressed.

  The chamfering angle θ, the length L, and the curvature radius of the chamfered portions 11 and 21 described above can be confirmed by surface shape observation by a known instrumental analysis technique such as a laser microscope.

  Here, a method of manufacturing the cleaning blade according to the present invention will be described.

The first manufacturing method is the polishing method.
First, an elastic sheet serving as a material of the cleaning blade, for example, a long and wide rubber sheet, is produced by centrifugal molding. The centrifugal forming method is a method in which a liquid material is placed in a rotating cylindrical drum and a sheet-like long and wide elastic sheet is formed by centrifugal force. By this, for example, a long and wide elastic sheet having a thickness of about 2 mm can be produced.

  The elastic sheet produced in this manner is cut into a predetermined size by a predetermined blade to produce a cleaning blade having an intended shape. While the edge portion of the produced cleaning blade is in contact with a flat plate whose surface is roughened or a polishing sheet, both are slid to form a chamfered portion on the edge portion. As the flat plate, for example, fine files of # 2000 or less may be engraved, or alumina or the like may be fixed on the surface.

  According to the first manufacturing method, a long and wide elastic sheet, for example, a rubber sheet is simply prepared, and a cleaning blade having a chamfered portion on the edge easily without requiring a mold or the like is used. It can be made.

Next, the second manufacturing method is by a mold.
The material of the cleaning blade (for example, a rubber material or the like) is injected into a mold in which a portion corresponding to the chamfered portion is formed, and this is solidified and molded. Thus, a cleaning blade having a chamfered portion can be manufactured.

  According to the second manufacturing method, a flat plate or a polishing sheet for polishing the edge portion is unnecessary, and the time required for manufacturing is only the molding time, so the target cleaning blade can be manufactured in a short time. can do.

  EXAMPLES Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited thereto. In addition, although the display of "part" or "%" is used in an Example, unless otherwise indicated, it represents "mass part" or "mass%."

<< Preparation of Metal Oxide Particles 1 >>
The following components were placed in a wet sand mill containing alumina beads of 0.5 mm in diameter, and mixed at 30 ° C. for 6 hours. Thereafter, methyl ethyl ketone and alumina beads were separated by filtration and dried at 60 ° C. to produce metal oxide particles 1 having a polymerizable group.
Particle type: Tin oxide (number average primary particle size: 20 nm) 100 parts by mass Surface modifier: Exemplified compound S-14 10 parts by mass Methyl ethyl ketone 1000 parts by mass

<< Preparation of metal oxide particles 2 to 4 >>
Metal oxide particles 2 to 4 were prepared in the same manner as in the preparation of the metal oxide particle 1 except that the particle type and the surface modifier were changed as described in Table I.

<< Preparation of Metal Oxide Particles 5 >>
A metal oxide particle 5 was produced in the same manner as in the production of the metal oxide particle 1 except that the surface modifier was not added.

<< Preparation of Electrophotographic Photoreceptor E1 >>
(1) Preparation of Conductive Support The surface of a cylindrical aluminum support was cut to prepare a conductive support.

(2) Formation of Intermediate Layer The following components were mixed, and dispersion was performed for 10 hours by a batch system using a sand mill as a disperser to prepare a coating liquid for forming an intermediate layer. The prepared coating liquid for forming an intermediate layer was applied to the surface of the conductive support by a dip coating method, and dried at 110 ° C. for 20 minutes to form an intermediate layer having a layer thickness of 2 μm on the conductive support.
Polyamide resin (X1010, Daicel Evonik Co., Ltd.)
10 parts by mass Titanium oxide particles (SMT 500 SAS, Tayca Corporation) 11 parts by mass Ethanol 200 parts by mass

(3) Formation of Charge Generating Layer The following components were mixed, and using a circulating ultrasonic homogenizer (RUS-600 TCVP; Nippon Seiki Seisakusho Co., Ltd.), 0.1. By dispersing for 5 hours, a coating solution for forming a charge generation layer was prepared. The prepared coating liquid for forming a charge generation layer was applied to the surface of the intermediate layer by a dip coating method, and then dried to form a charge generation layer having a layer thickness of 0.3 μm on the intermediate layer.
Charge-generating substances (titanium phthalocyanines having distinct peaks at 8.3 °, 24.7 °, 25.1 °, 26.5 ° as measured by Cu-Kα characteristic X-ray diffraction spectrum and (2R, 3R) -2, Mixed crystal of 1: 1 adduct of 3-butanediol and unadded titanyl phthalocyanine)
24 parts by mass polyvinyl butyral resin "S-LEC BL-1" (manufactured by Sekisui Chemical Co., Ltd.)
12 parts by mass 3-methyl-2-butanone / cyclohexanone (volume ratio = 4: 1)
400 parts by mass

(4) Formation of Charge Transport Layer A coating solution for forming a charge transport layer containing the following components is applied to the surface of the charge generation layer by dip coating, dried at 120 ° C. for 70 minutes, and a charge transport layer having a layer thickness of 24 μm. It formed on the charge transport layer.
Charge transport substance represented by the following formula: Compound A 60 parts by mass Polycarbonate resin "Z300" (manufactured by Mitsubishi Gas Chemical Co., Ltd.)
100 parts by mass Antioxidant "IRGANOX 1010 (manufactured by BASF) 4 parts by mass

(5) Formation of Protective Layer The coating solution for forming a protective layer in which the following components were mixed was applied to the surface of the charge transport layer using a circular slide hopper coater. Next, the coating film was irradiated with ultraviolet light for 1 minute with a metal halide lamp to cure the coating film, thereby forming a protective layer having a layer thickness of 3.0 μm on the charge transport layer. In addition, following PFPE-A-4M shows the compound in which X represents a methacryloyloxy group in the formula of said PFPE-A-4.
Polymerizable monomer M6 120 parts by mass PFPE-A-4M 30 parts by mass Metal oxide particles 1 100 parts by mass Polymerization initiator "IRGACURE 819" (manufactured by BASF Japan Ltd.)
10 parts by mass 2-butanol 400 parts by mass

  Thus, an electrophotographic photosensitive member E1 was produced.

<< Preparation of Electrophotographic Photoreceptor E2 >>
An electrophotographic photosensitive member E2 was produced in the same manner as in the production of the electrophotographic photosensitive member E1, except that the composition of the coating solution for forming a protective layer was changed as follows.
Polymerizable monomer M2 120 parts by mass tetrafluoroethylene resin (polytetrafluoroethylene, PTFE) (Daikin Industries: Rubron L-2)
30 parts by mass Metal oxide particles 1 100 parts by mass Polymerization initiator "IRGACURE 819" (manufactured by BASF Japan Ltd.)
10 parts by mass 2-butanol 400 parts by mass

<< Preparation of electrophotographic photosensitive members E3 to E12>
In the preparation of the electrophotographic photosensitive member E1, electrophotographic photosensitive members E3 to E12 were prepared in the same manner except that the composition of the coating liquid for forming a protective layer was changed as described in Table I. In Table I, among the compounds used as the first and second PFPE compounds, X in the above formula represents a methacryloyloxy group when the end is M, and the one with the end A is in the above formula X represents an acryloyloxy group.

<< Preparation of Cleaning Blade C1 >>
An edge of a substantially rectangular (plate-like) urethane rubber cleaning blade attached to a full-color printing machine (bizhub PRESS C 1070; Konica Minolta Co., Ltd., “bizhub” is a registered trademark of the company) which contacts the electrophotographic photosensitive member On the other hand, the following polishing process was performed as the edge chamfering process.

A 3M precision polishing sheet (wrapping film sheet) # 8000 (particle size: 1 μm) was fixed to a cylindrical substrate, and while rotating the cylindrical substrate, the polishing sheet was brought into contact with the edge of the cleaning blade. Thus, a chamfered portion having a chamfering angle of 20 ° and a length of 7 μm when viewed from the axial direction of the electrophotographic photosensitive member was formed.
Thus, a cleaning blade C1 was produced.

<< Preparation of Cleaning Blades C2 to C5>
In the preparation of the cleaning blade C1, the polishing sheet is brought into contact with the cleaning blade such that the chamfering angle of the chamfered portion and the length as viewed from the axial direction of the electrophotographic photosensitive member are as described in Table II. Cleaning blades C2 to C5 were produced in the same manner as described above.

<< Preparation of Cleaning Blades C6 to C10 >>
In the preparation of the cleaning blade C1, the same procedure is followed except that the abrasive sheet is brought into contact with the cleaning blade so that the shape of the chamfer is a curved surface and the radius of curvature is as described in Table II. Cleaning blades C6 to C10 were produced.

<< Preparation of Cleaning Blade C11 >>
The chamfering process was not performed on the substantially rectangular parallelepiped (plate-like) urethane rubber cleaning blade, and this was used as a cleaning blade C11.

<< Preparation of Image Forming Apparatus P1 to P26>
An image forming apparatus is mounted on a full-color printing machine (bizhub PRESS C 1070; Konica Minolta Co., Ltd., “bizhub” is a registered trademark of the company) in the combination as described in Table III with the electrophotographic photosensitive member and the cleaning blade prepared above. P1 to P26 were produced.

<< Evaluation of Image Forming Apparatus P1 to P26 >>
The following evaluations were performed on each of the image forming apparatuses manufactured as described above. The evaluation results are shown in Table III.

<Measurement of dynamic coefficient of friction>
Using the automatic roll friction and wear analyzer TSf-500R manufactured by KYOWA as a measurement apparatus, the dynamic friction coefficient before the start of use of each of the electrophotographic photosensitive members prepared above was measured under the following conditions.
Contact member: Konica Minolta J paper 7 mm
Rotation speed: 100 rpm, 5 rot
External environment: 20 ° C, 50% RH
Load: 20g

<Evaluation of the occurrence of image blurring>
A solid longitudinal image was continuously printed on 2000 sheets in the A4 widthwise feed direction under a high temperature and high humidity environment (HH environment) at 30 ° C. and 85% RH using each of the image forming apparatuses manufactured above. Next, after the image forming apparatus was allowed to stand for 17 hours, a half image of the entire surface was output, and the occurrence of image blurring was confirmed by visual observation. When the image blur occurred, 10 half images of the entire surface were further output, and the 10th sheet was visually observed to confirm the occurrence of the image blur. This was repeated until the image blurring could not be confirmed, and was evaluated based on the following criteria. The case where evaluation result is "A"-"C" was determined to be pass.
A: Image blur not generated B: Image blur is generated but does not occur after outputting 10 sheets (there is no problem in practical use)
C: Image blurring occurs, but it does not occur after outputting 20 sheets (no problem in practical use)
D: Image blurring occurs, but it does not occur after outputting 30 sheets (there is a problem in practical use)
E: Image blur occurs, even after 30 prints (There is a problem in practical use)

<Evaluation of the amount of wear of the cleaning blade>
Using the image forming apparatus prepared above, 500,000 sheets of a solid longitudinal image are continuously printed in the direction of A4 widthwise feed in a high temperature and high humidity environment (HH environment) at 30 ° C. and 85% RH, before and after the printing The length of the edge (chamfered portion) of the cleaning blade as viewed in the axial direction of the electrophotographic photosensitive member was measured. The difference of the said length of the chamfer in the back and front of continuous printing was made into wear width, and it evaluated based on the following reference | standard. The case where evaluation result is "A"-"C" was determined to be pass.
A: Wear width is 0 μm or more and less than 10 μm B: Wear width is 10 μm or more and less than 20 μm C: Wear width is 20 μm or more and less than 30 μm D: Wear width is 30 μm or more and less than 40 μm E: Wear width is 40 μm or more

  As shown in Table III, the image forming apparatuses P1 to P22 show excellent results in each evaluation as compared with the image forming apparatuses P23 to P26. Therefore, it can be said that the image forming apparatuses P1 to P20 can exhibit high cleaning performance even at the beginning of the start of use of the cleaning blade and can suppress the wear of the cleaning blade.

10 and 20 cleaning blades 11 and 21 chamfered portion 100 image forming apparatus 413 photosensitive member (electrophotographic photosensitive member)
415 Cleaning unit

Claims (9)

An image forming apparatus, comprising: an electrophotographic photosensitive member; and a cleaning unit having a cleaning blade for removing residual toner on the electrophotographic photosensitive member,
The initial dynamic friction coefficient of the electrophotographic photosensitive member is 0.3 or less,
2. The image forming apparatus according to claim 1, wherein the cleaning blade is a plate-like elastic member, and a chamfered portion is provided at an edge that slides on the surface of the electrophotographic photosensitive member. The electrophotographic photosensitive member has a conductive support, a photosensitive layer disposed on the conductive support, and a protective layer disposed on the photosensitive layer,
The image forming apparatus according to claim 1, wherein the protective layer contains at least a polymerized and cured product of a composition including a polymerizable monomer and a perfluoropolyether compound having a polymerizable group.   The protective layer contains at least a polymerizable monomer, a first perfluoropolyether compound having 4 or more polymerizable groups, and a second perfluoropolyether compound having 0 to 3 polymerizable groups. The image forming apparatus according to claim 2, comprising a polymerized and cured product of the composition.   The image forming apparatus according to claim 2, wherein the composition contains metal oxide particles.   The image forming apparatus according to claim 4, wherein the metal oxide particles have a polymerizable group. The chamfered portion is planar,
The image forming apparatus according to any one of claims 1 to 5, wherein a chamfering angle of the chamfered portion with respect to the thickness direction of the cleaning blade is in a range of 5 to 50 °. The chamfered portion is planar,
The image forming apparatus according to any one of claims 1 to 6, wherein a length of the chamfered portion as viewed in an axial direction of the electrophotographic photosensitive member is 3 μm or more. The chamfered portion is planar,
The image forming apparatus according to any one of claims 1 to 7, wherein a length of the chamfered portion as viewed in an axial direction of the electrophotographic photosensitive member is 15 μm or less. The chamfered portion is curved,
The image forming apparatus according to any one of claims 1 to 5, wherein a radius of curvature of the chamfered portion is in a range of 5 to 15 μm.

Images