JP5589497B2 - Electrophotographic photosensitive member, process cartridge, and image forming apparatus - Google Patents

Description

  The present invention relates to an electrophotographic photosensitive member, a process cartridge, and an image forming apparatus.

  Patent Document 1 discloses an electrophotographic photosensitive member having a photosensitive layer on a conductive support, wherein the surface layer contains a fluorine-based resin powder and a fluorine-based graft polymer. It is disclosed.

  In Patent Document 2, a photoconductive layer made of a non-single crystal material based on silicon and a surface layer made of a non-single crystal material are laminated on the outer peripheral surface of a cylindrical conductive substrate. An image forming apparatus having a photoconductor and a cylindrical intermediate transfer body arranged so that the surfaces of the photoconductor and the surface are in contact with each other, and the portion where the photoconductor and the intermediate transfer body are in contact with each other The temperature is 15 to 60 ° C., and the dynamic friction deviation, which is the standard deviation of the dynamic friction force generated between the photosensitive member and the intermediate transfer member in the steady state, is smaller than the average value of the dynamic friction force. An image forming method is disclosed.

  Patent Document 3 discloses an electrophotographic process including a step of developing at least an electrostatic charge image on an electrophotographic photosensitive member with a developer containing toner, and a step of cleaning the toner on the electrophotographic photosensitive member using blade cleaning. In the image forming method, the surface roughness of the electrophotographic photosensitive member at a standard length of 15 mm is within a range of 0.01 to 2.5 μm at a 10-point average roughness Rz, and the turbidity of the toner is 1 to 50. An electrophotographic image forming method is disclosed.

  Patent Document 4 discloses a ten-point average roughness Rzjis (A) measured by sweeping in the circumferential direction of the peripheral surface of the electrophotographic photosensitive member having a plurality of dimple-shaped concave portions on the peripheral surface of the electrophotographic photosensitive member. 10-point average roughness Rzjis (B) measured by sweeping in the direction of the generatrix of the peripheral surface of the electrophotographic photosensitive member is 0.3 to 2.5 μm, and the electrophotographic The average interval RSm (C) of the unevenness measured by sweeping in the circumferential direction of the peripheral surface of the photoreceptor is 5 to 120 μm, and the average interval of unevenness measured by sweeping in the generatrix direction of the peripheral surface of the electrophotographic photoreceptor RSm (D) is 5 to 120 μm, and the ratio value (D / C) of the average interval RSm (D) to the average interval RSm (C) is 0.5 to 1.5. An electrophotographic photosensitive member is disclosed.

Patent Document 5 discloses a method in which residual toner on an electrostatic latent image holding member made of an organic photoreceptor is removed by a blade cleaning unit, and the electrostatic latent image holding member is repeatedly used to form an image. The outermost surface layer of the photoconductor contains inorganic particles having a Mohs altitude of 5 or more, and the photoconductor has a surface roughness (R _Z ) of 0.05 μm or more. An image forming method is disclosed in which development is performed using a toner containing a release agent having a diameter of 0.1 to 1.1 μm.

  In Patent Document 6, in an electrophotographic photosensitive member having a photosensitive layer and a protective layer on a conductive support, at least the surface layer contains fluorine atom-containing resin fine particles, and the surface of the surface layer is mechanically polished. An electrophotographic photoreceptor characterized by the above has been disclosed.

JP-A-63-221355 JP 2001-318505 A JP 2001-01881 A Table 2005/093518 JP 08-262756 A JP 05-265243 A

  SUMMARY OF THE INVENTION An object of the present invention is to provide an electrophotographic photosensitive member in which poor cleaning due to turning up of a cleaning blade is suppressed as compared with the case where the ten-point average roughness (Rz) on the surface is smaller than the following range. And

The above problem is solved by the following means. That is,
The invention of claim 1
A support and a photosensitive layer provided on the support;
It has a convex portion containing an aggregate in which fluorine-based resin particles are aggregated on the surface,
The ten-point average roughness in the surface (Rz) is Ri der than 2.0μm or less 1.0 .mu.m,
The surface layer disposed on the side farthest from the support has a content of 0.5% by mass or more and less than 1.0% by mass with respect to the content of the fluorine resin particles and the fluorine resin particles. And an fluorinated alkyl group-containing copolymer .

The invention of claim 2
The electrophotographic photoreceptor according to claim 1 , wherein the fluorinated alkyl group-containing copolymer includes a repeating unit represented by the following general formula (A).

In the general formula (A), l is an integer of 1 or more, p is 0 or an integer of 1 or more, t is an integer of 1 to 7, R ¹ is a hydrogen atom or an alkyl group, Z ¹ is − Represents CO-O-.

The invention of claim 3
The electrophotographic photosensitive member according to claim 1 or 2 ,
A toner removing unit having a cleaning blade for removing the toner remaining on the surface of the electrophotographic photosensitive member after transferring the toner image formed on the surface of the electrophotographic photosensitive member to the transfer target;
And a process cartridge that can be attached to and detached from the image forming apparatus.

The invention of claim 4
The electrophotographic photosensitive member according to claim 1 or 2 ,
Charging means for charging the surface of the electrophotographic photosensitive member;
Latent image forming means for forming a latent image on the surface of the charged electrophotographic photosensitive member;
Developing means for developing a latent image formed on the surface of the electrophotographic photosensitive member with a developer containing toner to form a toner image;
Transfer means for transferring the toner image formed on the surface of the electrophotographic photosensitive member to a transfer target;
A toner removing unit having a cleaning blade for removing toner remaining on the surface of the electrophotographic photosensitive member after transferring the toner image to the transfer target;
An image forming apparatus.

  According to the first aspect of the present invention, defective cleaning due to turning up of the cleaning blade is suppressed as compared with the case where the ten-point average roughness (Rz) on the surface is smaller than the above range.

According to the first aspect of the present invention, compared to the case where the content of the fluorinated alkyl group-containing copolymer is out of the above range, poor cleaning due to turning up of the cleaning blade is suppressed.

According to the invention of claim 2 , the surface layer is caused by turning up of the cleaning blade as compared with the case where the surface layer does not contain the fluorinated alkyl group-containing copolymer containing the repeating unit represented by the general formula (A). Cleaning failure is suppressed.

According to the third and fourth aspects of the present invention, compared to the case where the ten-point average roughness (Rz) on the surface of the electrophotographic photosensitive member is smaller than the above range, the deterioration of the image quality due to the defective cleaning is suppressed. The

It is sectional drawing which shows an example of the electrophotographic photoreceptor which concerns on this embodiment. It is a schematic diagram showing a mode that a convex part exists in the surface of the electrophotographic photoreceptor which concerns on this embodiment. 1 is an overall configuration diagram illustrating a first example of an image forming apparatus according to an exemplary embodiment. It is a whole block diagram which shows the 2nd example of the image forming apparatus which concerns on this embodiment.

  Hereinafter, embodiments of the present invention will be described in detail. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and repeated description is omitted as appropriate.

[Electrophotographic photoreceptor]
The electrophotographic photosensitive member of the present embodiment includes a support and a photosensitive layer formed on the support, and includes a convex portion containing an aggregate in which fluororesin particles are aggregated on the surface of the electrophotographic photosensitive member. The ten-point average roughness (Rz) on the surface of the electrophotographic photosensitive member is 1.0 μm or more and 2.0 μm or less.
However, in this embodiment, the surface layer disposed on the side farthest from the support is 0.5% by mass or more and 1.0% by mass with respect to the content of the fluorine resin particles and the fluorine resin particles. And a fluorinated alkyl group-containing copolymer having a content of less than that.
Since the electrophotographic photosensitive member of the present embodiment has the above-described configuration, the cleaning defect due to the turning-up of the cleaning blade is suppressed as compared with the case where the ten-point average roughness (Rz) on the surface is smaller than the above range. . The reason is not clear, but is presumed as follows.

  As a method of removing the toner on the surface of the electrophotographic photosensitive member remaining after the transfer, there is a method of bringing the tip of the cleaning blade into contact with the surface of the electrophotographic photosensitive member and scraping off the toner on the surface of the electrophotographic photosensitive member with the cleaning blade. . When this method is employed, when the operation of the image forming apparatus is started, a frictional force proportional to the coefficient of static friction is applied to the contact portion between the surface of the electrophotographic photosensitive member and the tip of the cleaning blade. The frictional force may cause a phenomenon that the tip of the cleaning blade is turned in the direction of travel of the surface of the electrophotographic photosensitive member (turning of the cleaning blade). The larger the is, the more likely it is to occur.

  Further, when the cleaning blade is turned over, there may be a cleaning failure in which the toner on the surface of the electrophotographic photosensitive member passes through without being scraped by the cleaning blade. When a cleaning failure occurs, the toner that has passed through adheres to the contact charging type charger, causing charging failure, causing image unevenness, or the toner that has passed through the image moves to the image and causes image defects such as color streaks. May cause image quality to deteriorate.

  On the other hand, in this embodiment, since the ten-point average roughness (Rz) on the surface of the electrophotographic photosensitive member is in the above range, the surface is rough and the static friction coefficient is small as compared with the case where the ten point average roughness (Rz) is smaller than the above range. Conceivable. In addition, the presence of aggregates in which the fluororesin particles are aggregated on the convex portions reduces the surface energy on the surface of the convex portions, and the static friction coefficient compared to the case where the aggregates are not present on the convex portions. Is considered to be even smaller. For this reason, when the operation of the image forming apparatus is started with the tip of the cleaning blade in contact with the convex portion of the surface of the electrophotographic photosensitive member, the cleaning blade is less likely to be turned up because the frictional force is smaller than that of the conventional configuration. Presumed to be. In the image forming apparatus and the process cartridge using the electrophotographic photosensitive member of this embodiment, the cleaning failure is suppressed because the cleaning blade is not easily turned over. For example, a contact charging type charging device is used. In addition, the above-described deterioration in image quality due to poor cleaning is suppressed.

In addition, when the ten-point average roughness (Rz) is too large, the chargeability differs between the convex portion and the concave portion (that is, where the surface layer is relatively thick and thin), for example, the electric charge is concentrated in the concave portion. Thus, it is considered that wear is partially promoted and uneven wear occurs. When an image is formed using an electrophotographic photosensitive member in which uneven wear has occurred, there may be a case where uneven image density occurs.
On the other hand, in this embodiment, since the ten-point average roughness (Rz) is in the above range, the partial wear promotion is suppressed as compared with the case where the ten-point average roughness (Rz) is larger than the above range, so that the wear unevenness is suppressed. . In the image forming apparatus and the process cartridge using the electrophotographic photosensitive member of the present embodiment, the uneven image density due to the uneven wear is less likely to occur.

Here, the ten-point average roughness (Rz) refers to the ten-point average roughness defined by JIS-B-0601 (1994). That is, the ten-point average roughness is from the highest to the fifth measured in the direction perpendicular to the average line from the straight line that is parallel to the average line and does not cross the cross-sectional curve in the portion extracted from the cross-sectional curve by the reference length. The difference between the average value of the altitude at the top of the mountain and the average value of the altitude at the bottom of the valley from the deepest to the fifth is expressed in micrometers (μm).
This ten-point average roughness (Rz) is measured using, for example, a surface roughness measuring device (SURFCOM 1500DX (manufactured by Tokyo Seimitsu Co., Ltd.)), measuring length 4 mm, cutoff wavelength 0.8 mm, measuring magnification 1000 times, measuring speed Measurement is performed by a method of 0.3 mm / sec, cutoff type Gaussian, and slope correction least square curve correction.
In addition, as a desirable range of the ten-point average roughness (Rz), for example, a range of 1.5 μm or more and 1.9 μm or less is exemplified, and a range of 1.6 μm or more and 1.8 μm or less is more desirable.

In this embodiment, the arithmetic average roughness (Ra) on the surface of the electrophotographic photosensitive member is, for example, in the range of 0.3 μm to 1.5 μm, preferably 0.8 μm to 1.4 μm. It is more preferably 0 μm or more and 1.3 μm or less. The arithmetic average roughness (Ra) is within the above range in addition to the ten-point average roughness (Rz) being within the above range, so that the arithmetic average roughness (Ra) is further out of the above range. The cleaning blade is prevented from turning over.
Here, the arithmetic average roughness (Ra) refers to the arithmetic average roughness defined by JIS-B-0601 (1994). That is, the arithmetic average roughness is obtained by extracting only the reference length from the cross-sectional curve in the direction of the average line, taking the X axis in the direction of the average line of the extracted portion, and taking the Y axis in the direction perpendicular to the average line. When the height curve is expressed by y = f (x), it means the value of Ra obtained by the following formula expressed in micrometers (μm). However, “l” in the following formula means the reference length.
The cross-sectional curve is measured by the same method as the ten-point average roughness.

In the present embodiment, the surface layer of the electrophotographic photosensitive member contains the fluorine resin particles and the fluorinated alkyl group-containing copolymer, and the amount of the fluorine resin particles contained in the entire surface layer is 0.5. The fluorinated alkyl group-containing copolymer is contained in the range of from mass% to 1.0 mass% . Here, the amount of the fluororesin particles contained in the entire surface layer is not only the fluororesin particles constituting the aggregates contained in the projections, but also other fluororesin particles (coagulations) contained in the surface layer. The amount also includes fluorine resin particles that do not constitute an aggregate.
When the content of the fluorinated alkyl group-containing copolymer is in the above range, cleaning defects caused by turning up of the cleaning blade are suppressed as compared with a case where the content is out of the above range.

In this embodiment, since the content of the fluorinated alkyl group-containing copolymer is less than conventional, for example, compared with the case where the fluorinated alkyl group-containing copolymer is not used or is contained in a large amount as in the past, It is considered that the size per one of the aggregates contained in the convex portion tends to increase. Therefore, it is presumed that the ten-point average roughness (Rz) can be easily controlled within the above range, the surface energy at the convex portion is likely to be lowered, and the cleaning blade is not easily turned over.
A desirable content of the fluorinated alkyl group-containing copolymer includes a range of 0.6% by mass to 0.9% by mass, and a range of 0.6% by mass to 0.7% by mass is more preferable. desirable.

  In the electrophotographic photoreceptor according to the exemplary embodiment, the layer configuration and the like are not particularly limited, and may include a function-integrated type photosensitive layer having both charge transport capability and charge generation capability, or charge transport. The structure may include a function-separated type photosensitive layer including a layer and a charge generation layer. In this embodiment, in addition to the support and the photosensitive layer, other layers such as an undercoat layer, an intermediate layer, and a protective layer may be provided as necessary.

  In the electrophotographic photoreceptor according to the exemplary embodiment, in the form in which the surface layer includes the fluororesin particles and the fluorinated alkyl group-containing copolymer as described above, for example, the function-integrated type photosensitive layer is the surface layer. Contains the above-mentioned fluorine-based resin particles and the like in the above-mentioned function-integrated photosensitive layer. Further, when any one of the functional separation type photosensitive layers including the charge transport layer and the charge generation layer is a surface layer, the layer corresponding to the surface layer contains fluorine-based resin particles and the like. . Further, when a protective layer is provided as a surface layer on the photosensitive layer, the protective layer contains fluorine-based resin particles and the like.

However, as will be described later, for example, when the thickness of the protective layer is 2.0 μm or less, fluorine-based resin particles or the like are added to the photosensitive layer (for example, the charge transport layer in the case of the function separation type) as the lower layer of the protective layer. If contained, the protective layer may not contain fluorine-based resin particles or the like. In that case, the protective layer and the photosensitive layer (in the case of a function separation type, for example, a charge transport layer) correspond to the surface layer.
If the thickness of the protective layer is within the above range, even if the protective layer is coated on the convex portion formed by the aggregate of fluorine-based resin particles contained in the photosensitive layer, the convex portion formed on the surface is covered with the fluororesin. There are aggregates of particles. And even if the protective layer is coated, if the thickness is within the above range, it is considered that the effect of lowering the static friction coefficient due to the lowering of the surface energy due to the aggregates of the fluororesin particles contained in the projections can be obtained. It is done.

Hereinafter, as an example of the electrophotographic photoreceptor in the present exemplary embodiment, an embodiment having a function-separated type photosensitive layer and no protective layer will be described in detail.
FIG. 1 is a schematic cross-sectional view showing an example of the configuration of the electrophotographic photosensitive member according to this embodiment. The electrophotographic photoreceptor 21 has a structure in which an undercoat layer 24, a charge generation layer 25, and a charge transport layer 26 are laminated on a support 22 in this order. Constitutes a function-separated type photosensitive layer 23. Here, the charge transport layer 26 is a surface layer in the electrophotographic photoreceptor 21 (a layer disposed on the side farthest from the support 22).

-Charge transport layer (a layer corresponding to the above "surface layer")-
First, the charge transport layer 26 which is a layer corresponding to the “surface layer” will be described.
On the surface of the electrophotographic photosensitive member 21, that is, the surface of the charge transport layer 26 corresponding to the surface layer, as described above, there are convex portions containing aggregates in which the fluororesin particles are aggregated, and the ten-point average roughness. (Rz) is configured to be 1.0 μm or more and 2.0 μm or less.

  FIG. 2 is a schematic diagram showing a state in which the convex portions are present on the surface of the electrophotographic photosensitive member 21. As shown in FIG. 2, the surface 10 of the electrophotographic photosensitive member 21 has, for example, convex portions 12 (12 </ b> A and 12 </ b> B) that are raised from the peripheral portion 11. Specifically, the surface 10 of the charge transport layer 26 that is the surface layer of the electrophotographic photosensitive member 21 partially protrudes, and the convex portion 12 (outside the peripheral portion 11, that is, away from the rotation axis of the electrophotographic photosensitive member 21. Part protruding in the direction).

  And the convex part 12 is comprised including the aggregate 16 formed, for example by the several fluororesin particle | grains 14 gathering (that is, the aggregate 16 exists in the convex part 12 which is a part of surface layer). ing). In one of the convex portions 12 (the convex portion 12A), for example, the aggregate 16A is exposed from the surface, and in the other (the convex portion 12B), for example, the aggregate 16B is covered with the binder resin 18. The structure is not exposed from the surface.

FIG. 2 shows a form in which convex portions 12A including aggregates 14A exposed from the surface and convex portions 12B including aggregates 14B that are not exposed are mixed. You may have only the convex part 12A which exposed, and may have only the convex part 12B which the aggregate 14B does not expose.
However, from the viewpoint of obtaining an effect due to a decrease in surface energy caused by the aggregate 16 of the fluororesin particles 14 included in the convex portion 12, it is desirable to include the convex portion 12A where the aggregate 14A is exposed during use. On the other hand, even in the convex portion 12B where the aggregate 14B is not exposed, if the thickness of the binder resin 18 covering the aggregate 14B is 50 μm or less, the effect of the reduction in surface energy caused by the aggregate 16 can be obtained. Conceivable. Also, in the electrophotographic photosensitive member 21 having only the convex portions 12B in which the aggregate 16B is not exposed, for example, the electrophotographic photoreceptor 21 is mounted and operated in an image forming apparatus, and image formation is performed after the aggregate 16B is exposed. It is thought that the effect by the reduction of the surface energy resulting from the aggregate 16 can be obtained.

  As described above, in the charge transport layer 26, the fluorine resin particles 14 are present at least on the convex portion 12. However, in addition to the convex portion 12, the fluorine resin is also present in a place other than the convex portion 12 in the charge transport layer 26. Particles 14 may be present. The charge transport layer 26 may contain other components such as a binder resin 18 and a fluorinated alkyl group-containing copolymer in addition to the fluorine-based resin particles 14 as necessary. A charge transporting material may be included in order to develop the charge transporting ability that is an intrinsic function of the above.

(Fluorine resin particles 14)
Examples of the material of the fluorine-based resin particles 14 include tetrafluoroethylene resin (PTFE), trifluoroethylene chloride resin, hexafluoropropylene resin, vinyl fluoride resin, vinylidene fluoride resin, and difluorodiethylene chloride. Examples thereof include resins and copolymers thereof, and one or more of them are selected. Among these, for example, fluorine resin particles 14 containing a tetrafluoroethylene resin may be used from the viewpoint of wear resistance.

Examples of the average primary particle size of the fluororesin particles 14 include a range of 0.05 μm to 1 μm, and may be 0.1 μm to 0.5 μm.
The average primary particle size of the fluorine resin particles 14 is, for example, a laser diffraction particle size distribution measuring device LA-700 (manufactured by Horiba Seisakusho), and the refractive index of a measurement liquid in which the fluorine resin particles 14 are dispersed in a solvent. It is obtained by measuring at 1.35.

Examples of the volume average particle size of the aggregates 16 of the fluororesin particles 14 present on the convex portions 12 include a range of 100 μm to 200 μm, and may be 150 μm to 200 μm. In addition, the volume average particle diameter of the aggregate 16 existing in the convex portion 12 is measured, for example, by measuring the size of the convex portion having a diameter of 100 μm or more and 200 μm or less using an optical microscope, and calculating the diameter (average value) of the convex portion. Obtained In FIG. 2, an embodiment in which only one aggregate 16 is provided for one convex portion 12 is shown. However, the present invention is not limited to this, and a plurality of aggregates 16 are provided in one convex portion 12. You may have.
Moreover, as content of the fluorine-type resin particle 14 with respect to the whole charge transport layer 26, 1 mass% or more and 15 mass% or less are mentioned, for example, and 2 mass% or more and 12 mass% or less may be sufficient.

(Fluorinated alkyl group-containing copolymer)
The charge transport layer 26 may include a fluorinated alkyl group-containing copolymer that is a dispersion aid for the fluorine-based resin particles 14. The dispersion aid is a component used for controlling the dispersibility of the fluorinated resin particles 14, for example. For example, while maintaining the adsorptivity to the surface of the fluorinated resin particles 14, the dispersion aid is added to the charge transport layer 26. It has a function of maintaining compatibility with the binder resin 18 contained. When the fluorinated alkyl group-containing copolymer is used for the purpose of controlling the dispersibility of the fluorinated resin particles 14, it is added to, for example, a coating solution for forming the charge transport layer 26 as described later.

  Examples of the fluorinated alkyl group-containing copolymer include a copolymer containing a repeating unit represented by the following general formula (A). Further, as the fluorinated alkyl group-containing copolymer, a copolymer containing a repeating unit represented by the following general formula (A) and a repeating unit represented by the following general formula (B) may be used.

In the general formula (A), l is an integer of 1 or more, p is 0 or an integer of 1 or more, t is an integer of 1 to 7, R ¹ is a hydrogen atom or an alkyl group, Z ¹ is − Represents CO-O-.
In the general formula (B), m and n are each independently an integer of 1 or more, q, r, and s are each independently 0 or an integer of 1 or more, and R ² , R ³ , and R ⁴ are each Independently a hydrogen atom or an alkyl group, X is an alkylene chain, a halogen-substituted alkylene chain, -S-, -O-, -NH-, or a single bond, Y is an alkylene chain, a halogen-substituted alkylene chain,-(C _z H _2z-1 (OH)) —, or a single bond, Z ² represents —CO—O—. z represents an integer of 1 or more.

Moreover, as a fluorinated alkyl group containing copolymer, the copolymer containing the repeating unit further represented by the following general formula (C) is mentioned among the said copolymers, for example.

In the general formula (C), R ⁵ and R ⁶ each independently represent a hydrogen atom or an alkyl group, and y represents an integer of 1 or more.

Examples of the alkyl group represented by R ¹ , R ² , R ³ , R ⁴ , R ⁵ , and R ⁶ in the general formulas (A), (B), and (C) include, for example, methyl group, ethyl Group, propyl group and the like.
Although the upper limit of n is not specifically limited in the said general formula (B), For example, the range whose n is 1-60 is mentioned.
When the fluorinated alkyl group-containing copolymer is a copolymer containing a repeating unit represented by the above general formula (A) and a repeating unit represented by the above general formula (B), the above general formula (A) The ratio of l to m in the general formula (B) is, for example, in the range of 1: 9 to 9: 1 from the viewpoint of controlling the degree of aggregation of the fluororesin particles 14. Or from 3: 7 to 7: 3.

Moreover, as a weight average molecular weight of the said fluorinated alkyl group containing copolymer, the range of 50000-100,000 is mentioned, for example.
The weight average molecular weight is measured, for example, by gel permeation chromatography (GPC). The molecular weight measurement by GPC is performed using, for example, a Tosoh GPC / HLC-8120 as a measuring device, a Tosoh column / TSKgel GMHHR-M + TSKgel GMHHR-M (7.8 mm ID 30 cm), and a chloroform solvent. From this measurement result, a molecular weight calibration curve prepared with a monodisperse polystyrene standard sample is used for calculation.

The fluorinated alkyl group-containing copolymer has a ten-point average roughness (Rz) on the surface 10 of the electrophotographic photosensitive member 21 within the above range by controlling aggregation in the fluorine resin particles 14 among the copolymers. For example, t is preferably 6 or less.
As the fluorinated alkyl group-containing copolymer, for example, using a macromonomer composed of an acrylic ester compound, a methacrylic ester compound and the like, perfluoroalkylethyl (meth) acrylate, perfluoroalkyl (meth) acrylate, and the like, For example, it is synthesized by graft polymerization. Here, (meth) acrylate indicates acrylate or methacrylate.

(Charge transport material)
Examples of the charge transport material used for the charge transport layer 26 include oxadiazole derivatives such as 2,5-bis (p-diethylaminophenyl) -1,3,4-oxadiazole, Phenyl-pyrazoline, pyrazoline derivatives such as 1- [pyridyl- (2)]-3- (p-diethylaminostyryl) -5- (p-diethylaminostyryl) pyrazoline, triphenylamine, N, N′-bis (3 Aromatic tertiary amino compounds such as 4-dimethylphenyl) biphenyl-4-amine, tri (p-methylphenyl) aminyl-4-amine, dibenzylaniline, N, N′-bis (3-methylphenyl)- Aromatic tertiary diamino compounds such as N, N'-diphenylbenzidine, 3- (4'-dimethylaminophenyl) -5,6-di- (4'-meth) 1,2,4-triazine derivatives such as (ciphenyl) -1,2,4-triazine, hydrazone derivatives such as 4-diethylaminobenzaldehyde-1,1-diphenylhydrazone, and quinazoline derivatives such as 2-phenyl-4-styryl-quinazoline Benzofuran derivatives such as 6-hydroxy-2,3-di (p-methoxyphenyl) benzofuran, α-stilbene derivatives such as p- (2,2-diphenylvinyl) -N, N-diphenylaniline, enamine derivatives, N -Carbazole derivatives such as ethylcarbazole, hole transport materials such as poly-N-vinylcarbazole and its derivatives, quinone compounds such as chloranil and broanthraquinone, tetraanoquinodimethane compounds, 2,4,7-trinitro Fluorenone, 2,4,5,7-tetranitro-9-fu Examples thereof include fluorenone compounds such as luolenone, electron transport materials such as xanthone compounds and thiophene compounds, and polymers having groups composed of the above-described compounds in the main chain or side chain. These charge transport materials are used alone or in combination of two or more.

(Binder resin)
Examples of the binder resin 18 used for the charge transport layer 26 include polycarbonate resin such as bisphenol A type or bisphenol Z type, acrylic resin, methacrylic resin, polyarylate resin, polyester resin, polyvinyl chloride resin, polystyrene resin, acrylonitrile. -Styrene copolymer resin, acrylonitrile-butadiene copolymer resin, polyvinyl acetate resin, polyvinyl formal resin, polysulfone resin, styrene-butadiene copolymer resin, vinylidene chloride-acrylonitrile copolymer resin, vinyl chloride-vinyl acetate- Maleic anhydride resin, silicone resin, phenol-formaldehyde resin, polyacrylamide resin, polyamide resin, resin such as chlorinated rubber, polyvinyl carbazole, polyvinyl anne Spiral, organic photoconductive polymers such as polyvinyl pyrene, and the like. These binder resins 18 may be used alone or in combination of two or more.
In addition, as a compounding ratio of charge transport material and the said binder resin 18, the range of 10: 1 to 1: 5 is mentioned, for example.

(Other)
The fluorinated alkyl group-containing copolymer is a kind of dispersion aid for controlling the dispersibility of the fluorinated resin particles 14, but instead of the fluorinated alkyl group-containing copolymer or the fluorinated alkyl group. Other dispersion aids may be used together with the containing copolymer.
Examples of other dispersion aids include fluorine-containing surfactants, fluorine-containing polymers other than the fluorinated alkyl group-containing copolymer, silicone-based polymers, and silicone oils.

The charge transport layer 26 may include a leveling agent such as silicone oil or fluorine oil used for the purpose of controlling the smoothness of the surface.
As content of the said leveling agent in the charge transport layer 26, the range of 0.1 ppm or more and 1000 ppm or less is mentioned, for example, The range of 0.5 ppm or more and 500 ppm or less may be sufficient.

  As will be described later, the charge transport layer 26 is formed using a charge transport layer forming coating solution (hereinafter also referred to as “coating solution”) in which the above components are added to a solvent. Examples of the solvent used for forming the charge transport layer 26 include aromatic hydrocarbon solvents such as toluene and chlorobenzene, and aliphatic alcohol solvents such as methanol, ethanol, n-propanol, iso-propanol, and n-butanol. Ketone solvents such as acetone, cyclohexanone and 2-butanone, halogenated aliphatic hydrocarbon solvents such as methylene chloride, chloroform and ethylene chloride, and cyclic or linear ether solvents such as tetrahydrofuran, dioxane, ethylene glycol and diethyl ether And ester solvents such as methyl acetate, ethyl acetate, and n-butyl acetate. These solvents may be used alone or in combination of two or more. What is necessary is just to use what melt | dissolves the binder resin 18 as a mixed solvent as a solvent used when mixing.

(Method for producing charge transport layer 26)
In the present embodiment, the surface of the charge transport layer 26 has the convex portion 12 including the aggregate 16 of the fluororesin particles 14 and the ten-point average roughness (Rz) is in the above range. As a method for controlling the surface of the charge transport layer 26 so as to have the above-described configuration, for example, the aggregate 16 is formed by controlling the dispersibility of the fluorine-based resin particles 14 in the coating liquid, and the aggregate 16 is formed. A method of forming the charge transport layer 26 by applying a coating solution containing the above may be mentioned. By forming the charge transport layer 26 by this method, the aggregate 16 on the surface forms a convex portion, and the surface has the above configuration.

Moreover, as a method of controlling the dispersibility of the fluorine-based resin particles 14 in the coating liquid to form the aggregate 16, for example, a dispersion obtained by dispersing the fluorine-based resin particles 14 in a solvent is used with a high-pressure homogenizer described later. And a method of performing processing while controlling the processing conditions.
A high-pressure homogenizer is a medialess machine that performs processing without using a medium. For example, a collision method in which a dispersion is dispersed by liquid-liquid collision or liquid-wall collision in a high-pressure state, or in a high-pressure state. Examples include a penetrating method in which fine channels are penetrated and dispersed.

In any method, the processing conditions for controlling the dispersibility of the fluororesin particles 14 include, for example, the processing pressure (the pressure in the “high pressure state”), the number of processing times, and the generator (the pressure in the high pressure state). The shape, size, etc. of the member that converts to an ultra-high-speed flow are mentioned.
As the treatment pressure and the number of treatments are increased or increased, the dispersibility of the fluororesin particles 14 is improved. However, when the treatment pressure and the number of treatments are further increased or increased, aggregation tends to occur (overdispersed state). Accordingly, the processing pressure for setting the ten-point average roughness (Rz) in the above range is, for example, 300 kgf / cm ² or more and 1000 kgf / cm ² or less (2.9 × 10 ⁷ Pa or more and 9.6 × 10 ⁷ Pa or more). below) or 500 kgf / cm ² or more 1000 kgf / cm ² or less (4.9 × ¹⁰ 7 Pa or more 9.6 × ¹⁰ 7 Pa or less) range cited in, as the number of times of processing, for example to 10 times more than once or The range of 1 to 6 times is mentioned. Further, as the shape and size of the generator, for example, in the case of the penetration method, those having a diameter of the through hole in the range of 80 μm or more and 200 μm or less, for example, one having one or more through holes arranged, etc. It is done.

  The apparatus for performing the treatment is not limited to the high-pressure homogenizer. For example, a media disperser such as a ball mill, a vibration ball mill, an attritor, or a sand mill, or a medialess dispersion such as a stirrer, an ultrasonic disperser, or a roll mill. A machine may be used.

  Furthermore, when using the said dispersion | distribution adjuvant, the said process is performed, for example, after adding a dispersion | distribution adjuvant to the said dispersion liquid. When the fluorinated alkyl group-containing copolymer is used as a dispersion aid, the amount of the fluorinated alkyl group-containing copolymer with respect to the mass of the fluorinated resin particles 14 contained in the dispersion is also controlled. The dispersibility of the fluorine resin particles 14 is controlled. Specifically, for example, the addition amount of the fluorinated alkyl group-containing copolymer with respect to the mass of the fluororesin particles 14 contained in the dispersion may be in the range of 0.5% by mass to 1% by mass.

In addition to the fluorine resin particles 14 and the fluorinated alkyl group-containing copolymer, the coating liquid may contain other components such as a binder resin 18 and a charge transport material. The other components may be treated, for example, after adding the other components to the dispersion, or directly or separately dissolved in the solvent after the treatment. Alternatively, other dispersed components may be added.
Further, for example, after adding the fluororesin particles 14 and the fluorinated alkyl group-containing copolymer to a solvent containing the binder resin 18 and performing the above treatment, a charge transport material separately dissolved or dispersed in the solvent is used. Further, it may be added.

When the binder resin 18 and the fluorine resin particles 14 are included in the dispersion liquid for the above treatment, the amount of the binder resin 18 included in the dispersion liquid is the amount of the fluorine resin particles 14 included in the dispersion liquid. On the other hand, the range of 1 mass% or more and 70 mass% or less is mentioned, for example, The range of 5 mass% or more and 30 mass% or less may be sufficient.
Moreover, as content of the fluorine resin particle 14 in the said coating liquid, 1 mass% or more and 15 mass% or less are mentioned with respect to the total solid, for example, 2 mass% or more and 12 mass% or less may be sufficient. .

The charge transport layer 26 is formed by applying the coating liquid obtained as described above onto the charge generation layer 25 and drying it to remove the solvent. Examples of the method for applying the coating solution to the charge generation layer 25 include ordinary methods such as dip coating, push-up coating, wire bar coating, spray coating, blade coating, knife coating, and curtain coating. Can be mentioned.
Examples of the film thickness of the charge transport layer 26 include a range of 5 μm to 50 μm, and may be a range of 10 μm to 40 μm.
Hereinafter, layers other than the charge transport layer 26 in the electrophotographic photoreceptor 21 will be described.

-Support-
The material which comprises the support body 22 is not specifically limited, For example, the material which has electroconductivity is mentioned. Here, “conductive” means a range of 10 ¹⁰ Ωcm or less in volume resistivity.
Specific examples of the material constituting the support 22 include, for example, metals such as aluminum, nickel, chromium, and stainless steel, aluminum, titanium, nickel, chromium, stainless steel, gold, vanadium, tin oxide, and indium oxide. And a plastic film provided with a thin film such as ITO, or a paper or plastic film coated or impregnated with a conductivity-imparting agent.
The shape of the support 22 is not limited to a drum shape, and may be a sheet shape or a plate shape.
When a metal pipe is used as the support 22, the surface may remain as it is, or a process such as mirror cutting, etching, anodizing, rough cutting, centerless grinding, sand blasting, wet honing is performed in advance. Also good.

-Undercoat layer-
The undercoat layer 24 is provided as necessary for the purpose of preventing light reflection on the surface of the support 22 and preventing inflow of unnecessary carriers from the support 22 to the photosensitive layer 23, for example. Examples of the material of the undercoat layer 24 include metal powders such as aluminum, copper, nickel, and silver, conductive metal oxides such as antimony oxide, indium oxide, tin oxide, and zinc oxide, carbon fiber, and carbon. Examples thereof include a conductive material such as black or graphite powder dispersed in a binder resin and coated on a support. Further, two or more kinds of metal oxide particles may be mixed and used. Furthermore, the powder resistance may be controlled by performing surface treatment with a coupling agent on the metal oxide particles.

  Examples of the binder resin contained in the undercoat layer 24 include acetal resin, polyvinyl alcohol resin, casein, polyamide resin, cellulose resin, gelatin, polyurethane resin, polyester resin, methacrylic resin, acrylic resin, polyvinyl chloride resin, and polyvinyl alcohol. Acetate resin, vinyl chloride-vinyl acetate-maleic anhydride resin, silicone resin, silicone-alkyd resin, phenol resin, phenol-formaldehyde resin, melamine resin, urethane resin and other high molecular resin compounds, or charge having a charge transporting group Examples thereof include transport resins and conductive resins such as polyaniline.

The ratio of the metal oxide particles and the binder resin in the undercoat layer 24 is not particularly limited, and is set within a range where desired electrophotographic photoreceptor characteristics can be obtained.
In forming the undercoat layer 24, a coating solution in which the above components are added to a solvent is used.
Examples of the method for dispersing the metal oxide particles in the coating solution for forming the undercoat layer include a media disperser such as a ball mill, a vibration ball mill, an attritor, and a sand mill, and a stirrer, an ultrasonic disperser, a roll mill, a high-pressure homogenizer, and the like. A medialess disperser is used. Further, examples of the high-pressure homogenizer include a collision method in which the dispersion liquid is dispersed by liquid-liquid collision or liquid-wall collision in a high pressure state, and a penetration method in which the fine liquid is penetrated and dispersed in a high pressure state.

Examples of a method for applying the coating solution for forming the undercoat layer thus obtained on the support 22 include, for example, a dip coating method, a push-up coating method, a wire bar coating method, a spray coating method, a blade coating method, and a knife coating. Method, curtain coating method and the like. The film thickness of the undercoat layer 24 is, for example, 15 μm or more, and may be 20 μm and 50 μm or less. Resin particles may be added to the undercoat layer 24 in order to adjust the surface roughness.
Further, the surface of the undercoat layer 24 may be polished to adjust the surface roughness. As a polishing method, for example, buffing, sand blasting, wet honing, grinding or the like is used.

-Intermediate layer-
Although illustration is omitted, an intermediate layer may be further provided on the undercoat layer 24 in order to improve electrical characteristics, improve image quality, improve image quality maintenance, improve the adhesion of the photosensitive layer 23, and the like.
As the binder resin used for the intermediate layer, acetal resins such as polyvinyl butyral, polyvinyl alcohol resin, casein, polyamide resin, cellulose resin, gelatin, polyurethane resin, polyester resin, methacrylic resin, acrylic resin, polyvinyl chloride resin, polyvinyl In addition to polymer resins such as acetate resin, vinyl chloride-vinyl acetate-maleic anhydride resin, silicone resin, silicone-alkyd resin, phenol-formaldehyde resin, melamine resin, zirconium, titanium, aluminum, manganese, silicon atom, etc. An organometallic compound containing

In forming the intermediate layer, for example, a coating solution in which the binder resin or the like is dissolved in a solvent is applied to the undercoat layer 24. As the coating method, for example, usual methods such as a dip coating method, a push-up coating method, a wire bar coating method, a spray coating method, a blade coating method, a knife coating method, and a curtain coating method are used.
Moreover, as thickness of an intermediate | middle layer, the range of 0.1 micrometer or more and 3 micrometers or less is mentioned, for example.

-Charge generation layer-
The charge generation layer 25 is formed, for example, by dispersing a charge generation material in a binder resin. As the charge generation material, for example, phthalocyanine pigments such as metal-free phthalocyanine, chlorogallium phthalocyanine, hydroxygallium phthalocyanine, dichlorotin phthalocyanine, and titanyl phthalocyanine are used. More specifically, for example, a Bragg angle with respect to CuKα characteristic X-rays ( Chlorogallium phthalocyanine crystal having strong diffraction peaks at 2 ° ± 0.2 ° at least at 7.4 °, 16.6 °, 25.5 ° and 28.3 °, Bragg angle (2θ ± 0) with respect to CuKα characteristic X-ray .2 °) metal-free phthalocyanine crystals having strong diffraction peaks at 7.7 °, 9.3 °, 16.9 °, 17.5 °, 22.4 ° and 28.8 °, CuKα characteristic X-ray Bragg angle (2θ ± 0.2 °) with respect to at least 7.5 °, 9.9 °, 12.5 °, A hydroxygallium phthalocyanine crystal having strong diffraction peaks at 6.3 °, 18.6 °, 25.1 ° and 28.3 °, at least 9.6 of Bragg angle (2θ ± 0.2 °) with respect to CuKα characteristic X-ray Examples thereof include titanyl phthalocyanine crystals having strong diffraction peaks at °, 24.1 °, and 27.2 °. Examples of other charge generation materials include quinone pigments, perylene pigments, indigo pigments, bisbenzimidazole pigments, anthrone pigments, and quinacridone pigments. These charge generation materials may be used alone or in admixture of two or more.

  Examples of the binder resin in the charge generation layer 25 include polycarbonate resin such as bisphenol A type or bisphenol Z type, acrylic resin, methacrylic resin, polyarylate resin, polyester resin, polyvinyl chloride resin, polystyrene resin, and acrylonitrile-styrene. Polymer resin, acrylonitrile-butadiene copolymer, polyvinyl acetate resin, polyvinyl formal resin, polysulfone resin, styrene-butadiene copolymer resin, vinylidene chloride-acrylonitrile copolymer resin, vinyl chloride-vinyl acetate-maleic anhydride resin Silicone resin, phenol-formaldehyde resin, polyacrylamide resin, polyamide resin, poly-N-vinylcarbazole resin and the like are used. These binder resins may be used alone or in combination of two or more. The mixing ratio of the charge generation material and the binder resin is preferably in the range of 10: 1 to 1:10.

When the charge generation layer 25 is formed, a coating solution in which the above components are added to a solvent is used.
In order to disperse the charge generating material in the resin, the coating liquid may be subjected to a dispersion treatment. As a dispersion method, for example, a media disperser such as a ball mill, a vibrating ball mill, an attritor, or a sand mill, or a medialess disperser such as a stirrer, an ultrasonic disperser, a roll mill, or a high-pressure homogenizer is used. Further, examples of the high-pressure homogenizer include a collision method in which the dispersion liquid is dispersed by liquid-liquid collision or liquid-wall collision in a high pressure state, and a penetration method in which the fine liquid is penetrated and dispersed in a high pressure state.

  Examples of methods for applying the coating solution thus obtained onto the undercoat layer 24 include dip coating, push-up coating, wire bar coating, spray coating, blade coating, knife coating, curtain coating, and the like. Is mentioned. The film thickness of the charge generation layer 25 is, for example, 0.01 μm to 5 μm, and may be in the range of 0.05 μm to 2.0 μm.

In addition, for the purpose of preventing deterioration of the photoreceptor due to ozone, nitrogen oxide, or light and heat generated in the image forming apparatus, an antioxidant, a light stabilizer, and a heat stabilizer are included in each layer constituting the photosensitive layer 23. You may add additives, such as.
For example, examples of the antioxidant include hindered phenol, hindered amine, paraphenylenediamine, arylalkane, hydroquinone, spirochroman, spiroidanone and their derivatives, organic sulfur compounds, and organic phosphorus compounds.
Examples of light stabilizers include derivatives such as benzophenone, benzoazole, dithiocarbamate, and tetramethylpipen.

  As described above, the mode in which the function-separated type photosensitive layer 23 is provided, the protective layer is not provided, and the charge transport layer 26 is exposed on the surface has been described. However, the present invention is not limited thereto. Alternatively, the protective layer may be provided on the function-integrated type photosensitive layer or the function-separated type photosensitive layer 23.

When the protective layer is provided, for example, the protective layer is formed by applying a coating solution containing a conductive material in a binder resin onto the photosensitive layer.
The conductive material contained in the protective layer is not particularly limited, and examples thereof include metallocene compounds such as N, N′-dimethylferrocene, N, N′-diphenyl-N, N′-bis (3-methylphenyl) -Aromatic amine compounds such as [1,1′-biphenyl] -4,4′-diamine, molybdenum oxide, tungsten oxide, antimony oxide, tin oxide, titanium oxide, indium oxide, tin oxide and antimony, barium sulfate and oxidation A solid solution carrier with antimony, a mixture of the above metal oxides, a mixture of the above metal oxides in a single particle of titanium oxide, tin oxide, zinc oxide, or barium sulfate, or titanium oxide, tin oxide, Examples include zinc oxide or barium sulfate single particles coated with the above metal oxide.

  Examples of the binder resin constituting the protective layer include polyamide resin, polyvinyl acetal resin, polyurethane resin, polyester resin, epoxy resin, polyketone resin, polycarbonate resin, polyvinyl ketone resin, polystyrene resin, polyacrylamide resin, polyimide resin, and polyamide. Examples thereof include imide resins. These may be used by cross-linking each other as necessary.

As a coating method of the coating liquid for forming the protective layer, for example, a blade coating method, a wire bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method, a curtain coating method, etc. The method is used.
As a film thickness of a protective layer, 1 micrometer or more and 20 micrometers or less are mentioned, for example, and 2 micrometers or more and 10 micrometers or less may be sufficient.

[Image forming apparatus and process cartridge]
Hereinafter, the image forming apparatus and the process cartridge according to the present embodiment will be described.
FIG. 3 is an overall configuration diagram illustrating a first example of the image forming apparatus according to the present embodiment.
The image forming apparatus 1000 is a monochrome single-sided output printer that employs an electrophotographic system.

  As shown in FIG. 3, an image forming apparatus 1000 according to this embodiment is supplied with electric power from an electrophotographic photosensitive member (hereinafter referred to as a photosensitive member) 61 that rotates in the direction of arrow B in the figure, and a power source 65a. And a charging member 65 that is a charging means for charging the surface of the photoconductor 61 by rotating while contacting the photoconductor 61.

  Further, in this image forming apparatus 1000, exposure is an electrostatic latent image forming unit that emits laser light toward the photosensitive member 61 and forms an electrostatic latent image having a higher potential than the surroundings on the surface of the photosensitive member 61. The toner image is formed by developing the electrostatic latent image by attaching a monochrome (black) toner to the electrostatic latent image formed on the surface of the photosensitive member 61 using a developer including a black toner. The toner image formed on the surface of the photosensitive member 61 by pressing the conveyed paper P (transferred material) against the developing device 64, which is a developing means, and the photosensitive member 61 on which the toner image is formed is transferred to the photosensitive member 61. A transfer roll 66 that is a transfer unit that transfers onto a certain sheet P, and a fixing unit 70 that is a fixing unit that fixes the transferred image onto the sheet P by applying heat and pressure to the toner image transferred onto the sheet P. , Contact the photoreceptor 61, toner A cleaning device 62, which is a toner removing unit provided with a cleaning blade 62a that removes residual toner remaining on the surface of the photoconductor 61 after the transfer of the image, and a static elimination that removes the charge remaining on the photoconductor 61 after the transfer of the toner image. A lamp 67a is also provided.

  In this image forming apparatus 1000, both the charging member 65 and the photoreceptor 61 are in the form of rolls, and both ends of these rolls are supported by the support member 100a in such a manner that the roll rotates. In addition, the cleaning device 62 and the developing device 64 described above are also connected to the support member 100a. Thus, the charging member 65, the photoreceptor 61, the cleaning device 62, and the developing device 64 are integrated with the support member 100a. As a result, the process cartridge 100 is configured.

  By incorporating this process cartridge into the image forming apparatus 1000, the image forming apparatus 1000 is provided with each part that is a component of these process cartridges. This process cartridge 100 corresponds to an example of the process cartridge of the present embodiment.

Hereinafter, an image forming operation in the image forming apparatus 1000 will be described.
The image forming apparatus 1000 includes a toner cartridge (not shown) in which black toner is stored, and the toner is supplied to the developing device 64 by the toner cartridge. Further, the paper P used for transferring the toner image is stored in the paper storage member 80, and is conveyed from the paper storage member 80 when an image formation is instructed by the user, and is transferred by the transfer roll 66. After the toner image is transferred, it is conveyed toward the left in the figure. In FIG. 3, the sheet conveyance path at this time is shown as a path indicated by a left-pointing arrow, and the sheet P passes through the sheet conveyance path and is transferred onto the sheet P by the fixing unit 70. After fixing, it is discharged leftward.

  When the charging member 65 charges the photoreceptor 61, a voltage is applied to the charging member 65. The voltage range may be, for example, positive or negative from 50 V to 2000 V, and may be from 100 V to 1500 V, depending on the required charging potential of the photoreceptor in the case of DC voltage. In the case where the AC voltage is superimposed, for example, the peak-to-peak voltage is in the range of 400 V to 1800 V, and may be in the range of 800 V to 1600 V. Examples of the frequency of the alternating voltage include 50 Hz to 20,000 Hz, and may be 100 Hz to 5,000 Hz.

  As the charging member 65, for example, a member provided with an elastic layer, a resistance layer, a protective layer, or the like on the outer peripheral surface of the core material is preferably used. The charging member 65 rotates at the same peripheral speed as the photosensitive member 61 without contacting the photosensitive member 61 by contacting the photosensitive member 61, and functions as a charging unit. It may be charged by rotating at a peripheral speed different from 61.

  As the exposure unit 67, an optical system device that exposes a light source such as a semiconductor laser, an LED (light emitting diode), and a liquid crystal shutter to the surface of the electrophotographic photosensitive member in a desired image manner is applied.

  As the developing device 64, a conventionally known developing device using a regular or reversal developer such as a one-component system or a two-component system is used.

  As the transfer means, in addition to a contact charging member such as a transfer roll 66, a contact transfer charger using a belt, a film, a rubber blade or the like, or a scorotron transfer charger using a corona discharge, a corotron transfer charger, etc. Can be mentioned.

The cleaning device 62 is for removing residual toner adhering to the surface of the electrophotographic photosensitive member after the transfer process, and the electrophotographic photosensitive member cleaned by removing the residual toner by the cleaning blade 62a is The image forming process is repeatedly used.
Examples of the material for the cleaning blade include urethane rubber, neoprene rubber, and silicone rubber.

  Since the image forming apparatus according to the present embodiment includes the static elimination lamp 67a, the phenomenon that the residual potential of the electrophotographic photosensitive member is brought into the next cycle when the electrophotographic photosensitive member is repeatedly used is prevented. Therefore, the image quality can be further improved. It should be noted that the image forming apparatus according to the present embodiment may or may not include the charge removal lamp 67a as necessary.

FIG. 4 is an overall configuration diagram illustrating a second example of the image forming apparatus according to the present embodiment.
The image forming apparatus 1001 of this embodiment is a color printer.

  The image forming apparatus 1001 includes photoconductors 61K, 61C, 61M, and 61Y that are electrophotographic photoconductors that rotate in the directions of arrows Bk, Bc, Bm, and By in the drawing, respectively. Here, the photoreceptors 61K, 61C, 61M, and 61Y correspond to an example of the electrophotographic photoreceptor according to the present embodiment.

  Further, around each photoconductor, charging members 65K, 65C, 65M, and 65Y that are charging means for charging the surface of the photoconductor by rotating while in contact with each photoconductor, and laser light on each charged photoconductor. Exposure units 67K, 67C, 67M, 67Y which are electrostatic latent image forming means for forming an electrostatic latent image for each color of black (K), cyan (C), magenta (M), and yellow (Y) by irradiation of The developing devices 64K, 64C, 64M, and 64Y, and the photosensitive members 61K, 61C, and 61M, which are developing means for developing the electrostatic latent images on the respective photosensitive members with a developer containing toners of the respective colors to form toner images of the respective colors. , 61Y is provided with cleaning devices 62K, 62C, 62M and 62Y which are toner removing means for removing residual toner on the surface with a cleaning blade.

  In the image forming apparatus 1001, the black charging member 65K, the photosensitive member 61K, the cleaning device 62K, and the developing device 64K among the above-described constituent elements are integrated into constituent elements of the process cartridge 100K. Similarly, a charging member 65C, a photosensitive member 61C, a cleaning device 62C, and a developing device 64C for cyan, a charging member 65M, a photosensitive member 61M, a cleaning device 62M, and a developing device 64M for magenta, and , The charging member 65Y, the photosensitive member 61Y, the cleaning device 62Y, and the developing device 64Y for yellow are integrated into the constituent elements of the process cartridges 100C, 100M, and 100Y. By incorporating these four process cartridges into the image forming apparatus 1001, the image forming apparatus 1001 is provided with each part that is a component of these process cartridges. Each of these process cartridges 100K, 100C, 100M, and 100Y corresponds to an example of a process cartridge according to the present embodiment.

  Further, the image forming apparatus 1001 includes an intermediate transfer belt 50 that is an intermediate transfer body that receives a transfer (primary transfer) of each color toner image formed on each photoconductor and conveys a primary transfer image. Primary transfer rolls 66K, 66C, 66M, and 66Y for primary transfer of toner images of respective colors to the transfer belt 50, a secondary transfer roll pair 69 for secondary transfer to the paper P, and 2 on the paper P. Four toner cartridges 40K, 40C, 40M, 40Y, and paper P are stored, which respectively supply toner of each color component to the fixing device 70, which is a fixing means for fixing the next transferred toner image. A sheet storage member 80 is also provided.

  The transfer target according to the present embodiment is not particularly limited as long as it is a medium that transfers a toner image formed on an electrophotographic photosensitive member. For example, when transferring directly from an electrophotographic photosensitive member to a transfer medium such as paper, paper or the like is the transfer medium. When an intermediate transfer member is used, the intermediate transfer member is a transfer target.

  Here, the intermediate transfer belt 50 circulates and moves in the direction of the arrow A in the figure in a state where tension is applied by the secondary transfer roll 69b and the drive roll 50a while receiving the drive force from the drive roll 50a.

  In the above description, the case where the intermediate transfer belt 50 is used as the intermediate transfer member has been described. However, the intermediate transfer member may have a belt shape like the intermediate transfer belt 50 or a drum shape. Also good. Examples of the resin material used as the base material of the intermediate transfer body in the case of a belt include polyimide resin, polycarbonate resin (PC), polyvinylidene fluoride (PVDF), polyalkylene terephthalate (PAT), and ethylene tetrafluoroethylene copolymer. (ETFE) / PC, ETFE / PAT, PC / PAT blend materials, resin materials such as polyester, polyether ether ketone, and polyamide, and resin materials using these as main raw materials. Further, a resin material and an elastic material may be blended and used.

Next, an image forming operation in the image forming apparatus 1001 will be described.
The four photoconductors 61K, 61C, 61M, and 61Y are charged by the charging members 65K, 65C, 65M, and 65Y, respectively, and further receive the laser light emitted from the exposure units 67K, 67C, 67M, and 67Y, and on the respective photoconductors. An electrostatic latent image is formed. The formed electrostatic latent image is developed with a developer containing toner of each color by the developing devices 64K, 64C, 64M, and 64Y to form a toner image. The toner images of the respective colors formed in this way are yellow (Y), magenta (M), cyan (C) on the intermediate transfer belt 50 in the primary transfer rolls 66K, 66C, 66M, and 66Y corresponding to the respective colors. ) And black (K) are sequentially transferred (primary transfer) and superposed to form a multicolor primary transfer image.

The multicolor primary transfer image is conveyed to the secondary transfer roll pair 69 by the intermediate transfer belt 50. On the other hand, in response to the formation of a multicolor primary transfer image, the paper P is taken out from the paper accumulating member 80 and transported by the transport roll 81, and the position is adjusted by the alignment roll pair 82. Then, the multi-color primary transfer image is transferred (secondary transfer) to the conveyed paper P by the secondary transfer roll pair 69, and further converted into a secondary transfer image on the paper P by the fixing device 70. Fixing processing is performed. After the fixing process, the paper P having the fixed image passes through the delivery roll pair 83 and is discharged to the paper discharge receiver 84.
The above is the description of the image forming operation in the image forming apparatus 1001.

  The process cartridge according to the present embodiment integrally includes the electrophotographic photosensitive member of the present embodiment and a cleaning unit that removes residual toner on the surface of the electrophotographic photosensitive member after the transfer with a cleaning blade. In addition, a charging means for charging the surface of the electrophotographic photosensitive member, an electrostatic latent image forming means for forming an electrostatic latent image on the charged electrophotographic photosensitive member surface, and a developer are used. Development means for developing the electrostatic latent image formed on the surface of the electrophotographic photosensitive member to form a toner image, and transfer means for transferring the toner image formed on the surface of the electrophotographic photosensitive member to the surface of the transfer target. You may have at least 1 type selected from a group.

  Hereinafter, although an example and a comparative example are explained, the present invention is not limited to the following examples at all.

[Example 1]
100 parts by mass of zinc oxide particles (average particle size: 70 nm, manufactured by Teica, specific surface area value: 15 m ² / g) are stirred and mixed with 500 parts by mass of methanol, and KBM603 (manufactured by Shin-Etsu Chemical Co., Ltd.) 1 is used as a silane coupling agent. .25 parts by mass was added and stirred for 2 hours. Thereafter, methanol was distilled off under reduced pressure, baking was performed at 120 ° C. for 3 hours, and zinc oxide particles surface-treated with a silane coupling agent were obtained.
60 parts by mass of the surface-treated zinc oxide particles, 0.6 parts by mass of alizarin, 13.5 parts by mass of blocked isocyanate (Sumidule 3173, manufactured by Sumitomo Bayern Urethane Co., Ltd.) as a curing agent, and butyral resin (BM -1, manufactured by Sekisui Chemical Co., Ltd.) 15 parts by mass of 38 parts by mass of a solution obtained by dissolving 85 parts by mass of methyl ethyl ketone and 25 parts by mass of methyl ethyl ketone, and 4 hours in a sand mill using glass beads having a diameter of 1 mm. Dispersion was performed to obtain a dispersion. To the obtained dispersion, 0.005 parts by mass of dioctyltin dilaurate and 4.0 parts by mass of silicone resin particles (Tospearl 145, manufactured by GE Toshiba Silicone) are added as a catalyst, and a coating liquid for forming an undercoat layer is added. Obtained. This coating solution was applied on an aluminum substrate having a diameter of 30 mm × 365 mmL by a dip coating method, followed by drying and curing at 180 ° C. for 40 minutes to obtain an undercoat layer having a thickness of 19 μm.

  Next, as a charge generation material, at least 7.5 °, 9.9 °, 12.5 °, 16.3 °, 18.6 °, Bragg angle (2θ ± 0.2 °) with respect to CuKα characteristic X-ray, 15 parts by mass of hydroxygallium phthalocyanine crystals having strong diffraction peaks at 25.1 ° and 28.3 °, 10 parts by mass of vinyl chloride-vinyl acetate copolymer resin (VMCH, manufactured by Nippon Union Carbide) and n-butyl alcohol A mixture composed of 300 parts by mass was dispersed for 4 hours in a sand mill using glass beads having a diameter of 1 mm to obtain a coating solution for forming a charge generation layer. This coating solution for forming a charge generation layer was dip-coated on the undercoat layer and dried to obtain a charge generation layer having a thickness of 0.2 μm.

Next, A: 0.5 part by mass of tetrafluoroethylene resin particles (average primary particle size: 0.2 μm), a repeating unit represented by the following structural formula (A-1), and the following structural formula (B-1) Fluoroalkyl group-containing copolymer containing a repeating unit represented by the formula (weight average molecular weight 50,000, l: m = 1: 1, s = 1, n = 60) 0.04 part by mass of tetrahydrofuran 4 In addition to 1 part by mass and 1 part by mass of toluene, the mixture was kept at a liquid temperature of 20 ° C. and stirred for 30 hours to obtain a tetrafluoroethylene resin particle suspension (liquid A).
Next, B: 2 parts by mass of N, N′-bis (3-methylphenyl) -N, N′-diphenylbenzidine as a charge transport material, N, N′-bis (3,4-dimethylphenyl) biphenyl-4 -Mixing 2 parts by weight of amine, 6 parts by weight of bisphenol Z-type polycarbonate resin (viscosity average molecular weight: 50,000), and 0.1 part by weight of 2,6-di-t-butyl-4-methylphenol as an antioxidant Then, in addition to a mixed solvent of 24 parts by mass of tetrahydrofuran and 11 parts by mass of toluene, a liquid B was obtained.

After the A liquid was added to the B liquid and stirred and mixed, a high-pressure homogenizer equipped with a through-type chamber having fine flow paths (manufactured by Yoshida Kikai Kogyo Co., Ltd., shape and size of the generator: through hole diameter 80 μm, Using several hundreds of through holes), the pressure was increased to 500 kgf / cm ² (4.9 × 10 ⁷ Pa), and the dispersion treatment was performed once. Dimethyl silicone oil (trade name: KP-340, manufactured by Shin-Etsu Silicone Co., Ltd.) was added to the liquid obtained by the dispersion treatment so as to be 8 ppm, and stirred to obtain a coating liquid for forming a charge transport layer.

  Note that the fluorinated alkyl group-containing copolymer to be used (fluorinated alkyl group-containing copolymer including the repeating unit represented by the structural formula (A-1) and the repeating unit represented by the structural formula (B-1). After the synthesis, the mixture was heat-treated at 160 ° C. for 2 hours, dissolved in tetrahydrofuran, subjected to 100 KHz ultrasonic waves for 30 minutes, and then stirred dropwise into methanol. The obtained precipitate was separated from methanol by suction filtration, and the collected precipitate was dried at 80 ° C. for 24 hours by a vacuum dryer. Then, after dissolving again in tetrahydrofuran and applying ultrasonic waves of 100 KHz for 30 minutes, the mixture was stirred and dropped into methanol. The resulting precipitate was separated from methanol by suction filtration, and the collected precipitate was removed with a vacuum dryer. It was dried at 80 ° C. for 24 hours. The thus purified copolymer was used in the above examples.

The obtained coating solution for forming a charge transport layer was applied onto the charge generation layer and dried at 120 ° C. for 40 minutes to form a charge transport layer having a thickness of 34 μm, thereby obtaining the intended electrophotographic photosensitive member.
Using the electrophotographic photoreceptor thus obtained, the following tests were conducted.
In addition, as a result of measuring the volume average particle diameter of the aggregate of the fluororesin particles contained in the convex portions on the surface of the obtained electrophotographic photosensitive member by the method described above, it was 150 μm.

(Evaluation of convex portions including aggregates of fluororesin particles on the surface)
The surface of the obtained photoreceptor was visually observed. Observation was performed over the front surface of the photoreceptor, and it was evaluated whether or not a convex portion containing an aggregate of fluororesin particles was confirmed on the surface.

(Surface roughness evaluation)
The surface roughness of the obtained photoreceptor was measured with a surfcom roughness measuring instrument manufactured by Tokyo Seimitsu using a 0.2 μmR measuring needle, and a length of 4 mm was measured at a pulling speed of 0.3 mm / sec. Other measurement conditions are as described above. The measurement locations were 35 mm, 180 mm, and 330 mm in the axial direction from one end of the photoconductor, and four measurements were made in the circumferential direction, for a total of 12 measurements. The average value of the arithmetic average roughness obtained by the measurement was Ra, and the average value of the ten-point average roughness was Rz.

(M / C evaluation)
An electrophotographic photosensitive member was mounted on a monochrome printer Docu Center III C3300 drum cartridge manufactured by Fuji Xerox Co., Ltd., a halftone image was formed, and density unevenness was visually observed (initial image quality). Further, after 10000 halftone image quality images were formed, the halftone image quality images were formed, and density unevenness was visually observed (image quality after running). After the image quality evaluation, the drum cartridge was taken out of the printer and visually observed for blade turning.

Evaluation criteria for density unevenness (image quality) evaluation are as follows.
G1: There is no density unevenness and the image quality is good.
G2: Density unevenness slightly occurs but is within an allowable range.
G3: Density unevenness occurs remarkably and exceeds the allowable range.

  Table 1 shows the results obtained by the above experiment. Further, the ten-point average roughness (Rz) and arithmetic average roughness (Ra) on the surface of the obtained electrophotographic photosensitive member were measured by the above-described method, and the fluorine resin particles contained in the charge transport layer were measured. Table 1 also shows the content of the fluorinated alkyl group-containing copolymer relative to the amount (shown as “copolymer content (mass%)” in Table 1).

[Example 2]
Instead of the fluorinated alkyl group-containing copolymer containing the repeating unit represented by the structural formula (A-1) and the repeating unit represented by the structural formula (B-1), the following structural formula (C-1 ) And a fluorinated alkyl group-containing copolymer containing a repeating unit represented by the following structural formula (D-1) (weight average molecular weight: 50000, l: m = 1: 1, n = 60). )) Was used in the same manner as in Example 1 except that 0.04 parts by mass was used. Evaluation similar to Example 1 was performed using the obtained electrophotographic photosensitive member. The obtained results are shown in Table 1.

[Example 3]
In a dispersion treatment using a high-pressure homogenizer (manufactured by Yoshida Kikai Kogyo Co., Ltd.), instead of performing the dispersion treatment once by increasing the pressure to 500 kgf / cm ² (4.9 × 10 ⁷ Pa), 300 kgf / cm ² (2. An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the pressure was increased to 9 × 10 ⁷ Pa) and the dispersion treatment was performed three times. Evaluation similar to Example 1 was performed using the obtained electrophotographic photosensitive member. The obtained results are shown in Table 1.

[Example 4]
The amount of addition of the fluorinated alkyl group-containing copolymer was changed to 0.003 parts by mass, and the number of dispersion treatments of the high-pressure homogenizer (manufactured by Yoshida Kikai Kogyo Co., Ltd.) was changed to 6 times. A photographic photoreceptor was prepared. Evaluation similar to Example 1 was performed using the obtained electrophotographic photosensitive member. The obtained results are shown in Table 1.

[Example 5]
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the number of dispersion treatments of the high-pressure homogenizer was 10. Evaluation similar to Example 1 was performed using the obtained electrophotographic photosensitive member. The obtained results are shown in Table 1.

[Example 6]
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that a high-pressure homogenizer (Yoshida Kikai Kogyo Co., Ltd., shape and size of generator: diameter of through hole 80 μm, number of through holes 50) was used. Evaluation similar to Example 1 was performed using the obtained electrophotographic photosensitive member. The obtained results are shown in Table 1.

[Example 7]
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the addition amount of the fluorinated alkyl group-containing copolymer was changed to 0.005 parts by mass. Evaluation similar to Example 1 was performed using the obtained electrophotographic photosensitive member. The obtained results are shown in Table 1.

[Example 8]
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the addition amount of the fluorinated alkyl group-containing copolymer was changed to 0.0025 parts by mass. Evaluation similar to Example 1 was performed using the obtained electrophotographic photosensitive member. The obtained results are shown in Table 1.

[Example 9]
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the pressure (treatment pressure) of the high-pressure homogenizer was 1000 kgf / cm ² (9.8 × 10 ⁷ Pa). Evaluation similar to Example 1 was performed using the obtained electrophotographic photosensitive member. The obtained results are shown in Table 1.

[Comparative Example 1]
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the addition amount of the fluorinated alkyl group-containing copolymer was 0.012 parts by mass. Evaluation similar to Example 1 was performed using the obtained electrophotographic photosensitive member. The obtained results are shown in Table 1.

[Comparative Example 2]
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the number of dispersion treatments of the high-pressure homogenizer was changed to 6. Evaluation similar to Example 1 was performed using the obtained electrophotographic photosensitive member. The obtained results are shown in Table 1.

[Comparative Example 3]
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the addition amount of the fluorinated alkyl group-containing copolymer was 0.002 parts by mass. Evaluation similar to Example 1 was performed using the obtained electrophotographic photosensitive member. The obtained results are shown in Table 1.

[Comparative Example 4]
The same as in Example 1 except that the pressure (treatment pressure) of the high-pressure homogenizer was 1000 kgf / cm ² (9.8 × 10 ⁷ Pa) and the addition amount of the fluorinated alkyl group-containing copolymer was 0.012 parts by mass. Thus, an electrophotographic photosensitive member was produced. Evaluation similar to Example 1 was performed using the obtained electrophotographic photosensitive member. The obtained results are shown in Table 1.

  From the above results, it was found that in the example, the cleaning blade was prevented from being turned over and the initial image quality was good as compared with the comparative example. Moreover, in the Example, it turned out that the image quality after a running is favorable compared with a comparative example.

21 electrophotographic photosensitive member, 22 support, 23 photosensitive layer, 24 undercoat layer, 25 charge generation layer, 26 charge transport layer, 40K, 40C, 40M, 40Y toner cartridge, 50 intermediate transfer belt (transferred material), 50a Driving roll, 61, 61K, 61C, 61M, 61Y photoreceptor (electrophotographic photoreceptor), 62, 62K, 62C, 62M, 62Y cleaning device (toner removing means), 62a cleaning blade, 64, 64K, 64C, 64M, 64Y developing device (developing means), 65, 65K, 65C, 65M, 65Y charging member (charging means), 65a power supply, 66 transfer roll (transfer means), 66K, 66C, 66M, 66Y primary transfer roll, 67, 67K , 67C, 67M, 67Y Exposure section (latent image forming means), 67a Static elimination lamp, 69 Secondary transfer roll pair, 9b Secondary transfer roll (transfer means), 70 fixing device, 80 sheet storage member, 81 transport roll, 82 alignment roll pair, 83 delivery roll pair, 100, 100K, 100C, 100M, 100Y process cartridge, 100a support member, 1000, 1001 Image forming apparatus, P paper (transfer object)

Claims (4)

A support, and a photosensitive layer provided on the support,
It has a convex portion containing an aggregate in which fluorine-based resin particles are aggregated on the surface,
The ten-point average roughness in the surface (Rz) is Ri der than 2.0μm or less 1.0 .mu.m,
The surface layer disposed on the side farthest from the support has a content of 0.5% by mass or more and less than 1.0% by mass with respect to the content of the fluorine resin particles and the fluorine resin particles. And an fluorinated alkyl group-containing copolymer . The electrophotographic photoreceptor according to claim 1 , wherein the fluorinated alkyl group-containing copolymer includes a repeating unit represented by the following general formula (A).



[In the above general formula (A), l is an integer of 1 or more, p is 0 or an integer of 1 or more, t is an integer of 1 or more and 7 or less, R ¹ is a hydrogen atom or an alkyl group, and Z ¹ is -CO-O- is represented. ] The electrophotographic photosensitive member according to claim 1 or 2 ,
A toner removing unit having a cleaning blade for removing the toner remaining on the surface of the electrophotographic photosensitive member after transferring the toner image formed on the surface of the electrophotographic photosensitive member to the transfer target;
And a process cartridge that is detachably attached to the image forming apparatus. The electrophotographic photosensitive member according to claim 1 or 2 ,
Charging means for charging the surface of the electrophotographic photosensitive member;
Latent image forming means for forming a latent image on the surface of the charged electrophotographic photosensitive member;
Developing means for developing a latent image formed on the surface of the electrophotographic photosensitive member with a developer containing toner to form a toner image;
Transfer means for transferring the toner image formed on the surface of the electrophotographic photosensitive member to a transfer target;
A toner removing unit having a cleaning blade for removing toner remaining on the surface of the electrophotographic photosensitive member after transferring the toner image to the transfer target;
An image forming apparatus.