JP2011065065A - Image forming apparatus and process cartridge - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus suppressing an uneven surface potential of an electrophotographic photoreceptor. <P>SOLUTION: The image forming apparatus includes an electrophotographic photoreceptor, which includes, in the following order: a substrate; a photosensitive layer; and a protective layer having a first region which contains oxygen and gallium and is present in an outer circumference surface side, and a second region which is present closer than the first region to the substrate and has a larger atomic ratio of [oxygen/gallium] than in the first region. The apparatus further includes, in a periphery of the photoreceptor: a charging means charging the surface of the electrophotographic photoreceptor; a latent image forming means forming an electrostatic latent image by exposing the surface of the electrophotographic photoreceptor charged by the charging means; a developing means storing a developer containing a toner and developing the electrostatic latent image formed on the electrophotographic photoreceptor with the developer to form a toner image; a transfer means transferring the toner image formed on the electrophotographic photoreceptor onto a recording medium; and a supplying means supplying a material that suppresses injection of charges into the surface of the electrophotographic photoreceptor, to the surface of the photoreceptor. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to an image forming apparatus and a process cartridge.

The electrophotographic method is widely used for copying machines, printers, and the like.
In recent years, regarding an electrophotographic photosensitive member (hereinafter sometimes referred to as “photosensitive member”) used in an image forming apparatus utilizing electrophotography, a surface layer (protective layer) is provided on the surface of the photosensitive layer of the photosensitive member. Technology is being considered.

For example, an electrophotographic photosensitive member having a photoconductive layer made of a non-single crystal mainly composed of silicon, and a technique in which a surface layer contains magnesium fluoride as a main component is known (for example, see Patent Document 1). ).
There is also known an electrophotographic photosensitive member in which an organic photosensitive layer is formed on a conductive substrate, and a surface protective layer made of amorphous silicon carbide is formed on the organic photosensitive layer by catalytic CVD under specific conditions. (For example, refer to Patent Document 2).
Further, as the surface layer of the photoreceptor, a surface layer containing gallium in amorphous carbon (see, for example, Patent Document 3), a surface layer containing amorphous carbon nitride having a diamond bond (see, for example, Patent Document 4), non- A surface layer containing a single-crystal hydrogenated nitride semiconductor (for example, see Patent Document 5) is known.
Furthermore, a surface layer containing oxygen and a group 13 element and having an oxygen content on the outermost surface exceeding 15 atomic% (see, for example, Patent Document 6), an element composition ratio including oxygen and a group 13 element (oxygen / 13 A surface layer (for example, see Patent Document 7) having a group element) of 1.1 or more and 1.5 or less is known.

  In addition, for the purpose of preventing chipping and abrasion of the cleaning blade, a lubricant (for example, zinc stearate) is externally added to the developer and supplied to the surface of the electrophotographic photoreceptor having an organic surface layer. Is known (see, for example, Patent Document 8). Also known is a technique for supplying a lubricant (for example, zinc stearate) to the surface of an electrophotographic photoreceptor having an organic surface layer by an external supply device (see, for example, Patent Document 9).

JP 2003-29437 A JP 2003-316053 A JP-A-2-110470 JP 2003-27238 A Japanese Patent Laid-Open No. 11-186571 JP 2006-267507 A JP 2008-268266 A JP-A-2005-004051 JP 2006-267299 A

  An object of the present invention is to inject an electric charge to the surface of an electrophotographic photosensitive member on the surface of the electrophotographic photosensitive member in an image liquid apparatus employing an electrophotographic photosensitive member having a protective layer containing the following specific oxygen and gallium. It is an object of the present invention to provide an image forming apparatus in which unevenness of the surface potential of an electrophotographic photosensitive member is suppressed as compared with a case where a method for supplying a material that suppresses the above is not adopted.

The above problem is solved by the following means. That is,
The invention according to claim 1
A base, a photosensitive layer, oxygen and gallium, a first region existing on the outer peripheral surface side, and a side closer to the base than the first region, compared to the first region A protective layer having a second region having a large atomic ratio [oxygen / gallium], and an electrophotographic photosensitive member in this order;
Charging means for charging the surface of the electrophotographic photosensitive member; and latent image forming means for forming an electrostatic latent image by exposing the surface of the electrophotographic photosensitive member charged by the charging means;
Developing means for developing the electrostatic latent image formed on the electrophotographic photosensitive member with a developer containing toner to form a toner image;
Transfer means for transferring the toner image formed on the electrophotographic photosensitive member to a recording medium;
A supply means for supplying a material for suppressing charge injection to the surface of the electrophotographic photosensitive member on the surface of the electrophotographic photosensitive member;
An image forming apparatus.

The invention according to claim 2
A base, a photosensitive layer, oxygen and gallium, a first region existing on the outer peripheral surface side, and a side closer to the base than the first region, compared to the first region A protective layer having a second region having a large atomic ratio [oxygen / gallium], and an electrophotographic photosensitive member in this order;
A supply means for supplying a material for suppressing charge injection to the surface of the electrophotographic photosensitive member on the surface of the electrophotographic photosensitive member;
Process cartridge with

According to the first aspect of the present invention, in the image liquid apparatus employing the electrophotographic photosensitive member having the protective layer containing the specific oxygen and gallium, the surface of the electrophotographic photosensitive member is disposed on the surface of the electrophotographic photosensitive member. As compared with a case where a method of supplying a material that suppresses injection of electric charge into the electrophotographic photosensitive member is not adopted, unevenness of the surface potential of the electrophotographic photosensitive member is suppressed.
According to the second aspect of the present invention, in the process cartridge employing the electrophotographic photosensitive member having the protective layer containing the specific oxygen and gallium, the charge on the surface of the electrophotographic photosensitive member on the surface of the electrophotographic photosensitive member. As compared with a case where a method for supplying a material that suppresses injection of the electrophotographic photosensitive member is not adopted, unevenness of the surface potential of the electrophotographic photosensitive member is suppressed.

FIG. 2 is a schematic cross-sectional view illustrating an example of a layer configuration of an electrophotographic photosensitive member according to the present embodiment. It is a schematic cross section which shows another example of the layer structure of the electrophotographic photoreceptor which concerns on this embodiment. It is a schematic cross section which shows another example of the layer structure of the electrophotographic photoreceptor which concerns on this embodiment. It is a schematic cross section which shows another example of the layer structure of the electrophotographic photoreceptor which concerns on this embodiment. 1 is a schematic diagram illustrating an example of a film forming apparatus used for forming a protective layer of an electrophotographic photoreceptor according to an exemplary embodiment. It is a schematic diagram which shows the example of the plasma generator used for formation of the protective layer of the electrophotographic photoreceptor which concerns on this embodiment. 1 is a schematic configuration diagram illustrating an image forming apparatus according to an exemplary embodiment. It is a schematic block diagram which shows the image forming apparatus which concerns on other this embodiment.

  Embodiments that are examples of the present invention will be described below.

  The image forming apparatus according to this embodiment forms an electrostatic latent image by exposing an electrophotographic photosensitive member, a charging unit that charges the surface of the electrophotographic photosensitive member, and the surface of the electrophotographic photosensitive member charged by the charging unit. A latent image forming unit that stores developer, a developing unit that develops an electrostatic latent image formed on the electrophotographic photosensitive member with the developer, and forms a toner image; and a developer formed on the electrophotographic photosensitive member. A transfer unit that transfers a toner image to a recording medium, and a material that suppresses injection of charges into the surface of the electrophotographic photosensitive member (hereinafter also referred to as a charge injection suppressing material) are supplied to the surface of the electrophotographic photosensitive member. Supply means (hereinafter also referred to as charge injection suppression material supply means).

And as an electrophotographic photoreceptor, a substrate, a photosensitive layer, a protective layer containing oxygen and gallium, a first region existing on the outer peripheral surface side, and a side closer to the substrate than the first region And a protective layer having a second region having a larger atomic ratio [oxygen / gallium] (hereinafter also referred to as “atomic ratio [O / Ga]”) than the first region. The electrophotographic photoreceptors in order are employed.
That is, the protective layer is present in the distribution of atomic number ratio [oxygen / gallium] in the layer thickness direction, the first region existing on the outer peripheral surface side and the side closer to the substrate than the first region, And a second region having a larger atomic ratio [oxygen / gallium] than the first region.
The protective layer may have a region other than the first region and the second region as necessary.

Here, generally, when a protective layer containing oxygen and gallium is formed on the surface of the photosensitive layer of the electrophotographic photosensitive member, the sensitivity of the electrophotographic photosensitive member tends to decrease due to the formation of the protective layer. In particular, when the atomic ratio [oxygen / gallium] is decreased in the protective layer, the resistance of the layer is decreased, and the residual potential is decreased, the layer is colored due to light absorption in the entire visible region, and the sensitivity is greatly decreased. Tend.
However, as a result of this examination, a region (first region) having a relatively small atomic ratio [oxygen / gallium] is disposed on the side away from the base of the region containing oxygen and gallium (second region). As a result, it was revealed that a decrease in sensitivity due to the formation of the protective layer was suppressed. The cause is presumed that the first region has a function as a charge injection region and the second region has a function as a charge transport region, so that the residual potential can be reduced and light absorption is reduced at the same time. Is done. However, this embodiment is not limited by this cause.
Therefore, when the electrophotographic photosensitive member has the above-described configuration, the protective layer does not have the second region having an atomic ratio [oxygen / gallium] larger than the first region existing on the outer peripheral surface side. In comparison, a decrease in sensitivity due to the formation of the protective layer is suppressed. Furthermore, the residual potential is reduced by adopting the configuration of the present embodiment.

  On the other hand, the electrophotographic photosensitive member having the above characteristics tends to have a low surface resistance. Therefore, when developing the electrostatic latent image by the developing means, there is a tendency that charge injection is likely to occur. Potential unevenness may occur.

Therefore, in the image forming apparatus according to the present embodiment, the surface of the electrophotographic photosensitive member includes a charge injection suppressing material supply unit that supplies a charge injection suppressing material to the surface of the electrophotographic photosensitive member. The charge injection suppressing material supplying means supplies the charge injection suppressing material to the surface of the electrophotographic photosensitive member to form a film. Thereby, for example, when developing the electrostatic latent image by the developing means, it is considered that the injection of electric charge to the electrophotographic photosensitive member hardly occurs.
Therefore, in the image forming apparatus according to this embodiment, unevenness in the surface potential of the electrophotographic photosensitive member is suppressed. As a result, an image with good graininess can be obtained.

Hereinafter, the present embodiment will be described with reference to the drawings.
FIG. 7 is a schematic configuration diagram illustrating an image forming apparatus according to the present embodiment.

  As shown in FIG. 7, the image forming apparatus 101 according to the present embodiment includes, for example, an electrophotographic photosensitive member 10 that rotates clockwise as indicated by an arrow a, and an electrophotographic photosensitive member 10 above the electrophotographic photosensitive member 10. A charging device 20 (an example of a charging unit) that is provided relative to the photographic photosensitive member 10 and charges the surface of the electrophotographic photosensitive member 10, and the surface of the electrophotographic photosensitive member 10 charged by the charging device 20 is exposed to light. An exposure device 30 (an example of an electrostatic latent image forming unit) that forms an electrostatic latent image, and a toner contained in a developer is attached to the electrostatic latent image formed by the exposure device 30 to form an electrophotographic photosensitive member 10. A developing device 40 (an example of a developing unit) that forms a toner image on the surface and a toner image formed on the surface of the electrophotographic photoreceptor 10 while traveling in the direction indicated by the arrow b while contacting the electrophotographic photoreceptor 10 Belt-like transfer An intermediary transfer member 50, a charge injection suppressing material supplying device 60 for supplying a charge injection suppressing material 62 to the surface of the electrophotographic photosensitive member, and a cleaning device 70 for cleaning the surface of the electrophotographic photosensitive member 10 to remove transfer residual toner. (An example of a cleaning means).

  The charging device 20, the exposure device 30, the developing device 40, the intermediate transfer member 50, the charge injection suppressing material supply device 60, and the cleaning device 70 are arranged in a clockwise direction on the circumference surrounding the electrophotographic photosensitive member 10. Yes. In the present embodiment, a mode in which the charge injection suppression material supply device 60 is disposed in the cleaning device 70 will be described. However, the present invention is not limited to this, and the charge injection suppression material supply is performed separately from the cleaning device 70. The form which has arrange | positioned the apparatus 60 may be sufficient.

  The intermediate transfer member 50 is held from the inside while being tensioned by the support rollers 50A and 50B, the back roller 50C, and the drive roller 50D, and is driven in the direction of the arrow b as the drive roller 50D rotates. At a position facing the electrophotographic photosensitive member 10 inside the intermediate transfer member 50, the intermediate transfer member 50 is charged to a polarity different from the charging polarity of the toner, and the electrophotographic photosensitive member 10 is placed on the outer surface of the intermediate transfer member 50. A primary transfer device 51 for adsorbing the upper toner is provided. On the outer side below the intermediate transfer member 50, the recording paper P (an example of a recording medium) is charged to a polarity different from the charged polarity of the toner, and the toner image formed on the intermediate transfer member 50 is placed on the recording paper P. A secondary transfer device 52 for transferring is provided to face the back roller 50C. These members for transferring the toner image formed on the electrophotographic photosensitive member 10 to the recording paper P correspond to an example of a transfer unit.

  Below the intermediate transfer member 50, a recording paper supply device 53 that supplies the recording paper P to the secondary transfer device 52 and a recording paper P on which the toner image is formed in the secondary transfer device 52 are conveyed. A fixing device 80 for fixing the toner image is provided.

  The recording paper supply device 53 includes a pair of transport rollers 53A and a guide slope 53B that guides the recording paper P transported by the transport rollers 53A toward the secondary transfer device 52. On the other hand, the fixing device 80 includes a fixing roller 81 that is a pair of heat rollers for fixing the toner image by heating and pressing the recording paper P onto which the toner image has been transferred by the secondary transfer device 52, and a fixing roller. And a conveyance conveyor 82 that conveys the recording paper P toward 81.

  The recording paper P is conveyed in the direction indicated by the arrow c by the recording paper supply device 53, the secondary transfer device 52, and the fixing device 80.

  The intermediate transfer member 50 is further provided with an intermediate transfer member cleaning device 54 having a cleaning blade for removing the toner remaining on the intermediate transfer member 50 after the toner image is transferred to the recording paper P in the secondary transfer device 52. Yes.

  Details of main components in the image forming apparatus 101 according to the present embodiment will be described below.

(Electrophotographic photoreceptor)
The electrophotographic photosensitive member is a base, a photosensitive layer, a protective layer containing oxygen and gallium, and is present on the outer peripheral surface side, and on the side closer to the base than the first region. And a protective layer having a second region having a larger atomic ratio [oxygen / gallium] (hereinafter also referred to as “atomic number ratio [O / Ga]”) than the first region in this order.

In the electrophotographic photosensitive member, the first region and the second region may each have a clear interface with an adjacent region, or an unclear interface with an adjacent region.
Hereinafter, the first region when the interface with the adjacent region is clear is referred to as “first layer”, and the second region when the interface with the adjacent region is clear is referred to as “second layer”. "
That is, the protective layer is a first layer present on the outer peripheral surface side and is present on the side closer to the substrate than the first layer, and has a larger atomic ratio [oxygen / gallium] than the first layer. And two layers.

In the case where the protective layer includes the first layer and the second layer, the atomic ratio [oxygen / gallium] is between the first layer and the second layer so that the number of atoms in the first layer A form having an intermediate layer having a ratio [oxygen / gallium] or higher and an atomic ratio of the second layer [oxygen / gallium] or lower is desirable.
According to the form having the intermediate layer, an increase in residual potential and a decrease in sensitivity due to the formation of the protective layer are further reduced. This is presumed to be because the charge transport from the first layer to the second layer is more effectively performed. However, this form is not limited by this cause.

In the electrophotographic photosensitive member, the composition of the protective layer and the atomic ratio [oxygen / gallium] are obtained by, for example, Rutherford backscattering (RBS) including the distribution in the layer thickness direction.
RBS uses, for example, NEC 3SDH Pelletron as an accelerator, CE & A RBS-400 as an end station, and 3S-R10 as a system. For analysis, the CE & A HYPRA program or the like is used.
The RBS measurement conditions are: He ++ ion beam energy is 2.275 eV, detection angle is 160 °, and Grazing Angle is 109 ° with respect to the incident beam.

Specifically, the RBS measurement is performed as follows.
First, a He ++ ion beam is incident on the sample perpendicularly, a detector is set at 160 ° with respect to the ion beam, and the backscattered He signal is measured. The composition ratio and the film thickness are determined from the detected energy and intensity of He. In order to improve the accuracy of obtaining the composition ratio and the film thickness, the spectrum may be measured at two detection angles. Accuracy is improved by measuring and cross-checking at two detection angles with different depth resolution and backscattering dynamics.
The number of He atoms back-scattered by the target atom is determined by three factors: 1) the atomic number of the target atom, 2) the energy of the He atom before scattering, and 3) the scattering angle.
The density is assumed from the measured composition by calculation, and this is used to calculate the layer thickness. The density error is within 20%.

Even when the second region and the first region are continuously formed on the photosensitive layer as in this embodiment, the measurement method suppresses the destruction of the surface layer portion (first region). Meanwhile, the elemental composition of each of the first region and the second region is measured.
The content of each element in the entire protective layer is measured by, for example, secondary electron mass spectrometry or XPS (X-ray photoelectron spectroscopy).

Moreover, the protective layer in the present embodiment may have other regions other than the first region and the second region as necessary.
For example, you may have the 3rd area | region which exists in the side near a base | substrate rather than a 2nd area | region, and whose atomic ratio [oxygen / gallium] is small compared with a 2nd area | region.
In the embodiment having the third region, the distribution of the atomic number ratio [oxygen / gallium] in the thickness direction of the protective layer is such that the atomic number ratio [oxygen / gallium] is once changed from the first region on the outer peripheral surface side. It becomes larger (second region), the atomic ratio [oxygen / gallium] becomes smaller again (third region), and the distribution reaches the photosensitive layer.
According to the embodiment having the third region, the residual potential during repeated use is suppressed. That is, the repetition characteristics of the electrophotographic photosensitive member are improved. The reason for this is presumed to be that holes generated in the photosensitive layer by repeated use are injected into the third region. However, this form is not limited by this cause.
The third region may be a third layer having a clear interface with other regions.

In general, when the thickness of the protective layer is increased, the durability of the electrophotographic photosensitive member is improved, but the sensitivity tends to decrease greatly due to the formation of the protective layer.
As described above, the protective layer in the present embodiment has an effect of suppressing a decrease in sensitivity due to the formation of the protective layer, and thus is suitable for a form in which the protective layer is thick. That is, according to this embodiment, even when the layer thickness is increased, a decrease in sensitivity due to the formation of the protective layer is suppressed.
Therefore, the thickness of the protective layer is desirably 1.0 μm or more from the viewpoint of achieving both improvement in durability and suppression of reduction in sensitivity due to the formation of the protective layer. Furthermore, 1.5 μm or more is more desirable, 2.0 μm or more is further desirable, and 2.5 μm or more is particularly desirable.
The upper limit of the thickness of the protective layer is not particularly limited, but is 6.0 μm from the viewpoint of further reducing sensitivity reduction due to protective layer formation and residual potential increase.
As a method for confirming the durability of the electrophotographic photosensitive member, for example, a method for examining the presence or absence of scratches on the surface of the electrophotographic photosensitive member when image formation is repeatedly performed (the fewer the scratches, the higher the durability). .
Further, when the image formation is repeated, it may be checked whether the formed image has a white streak-like image defect due to a scratch on the surface of the electrophotographic photosensitive member (a white streak-like image defect). The smaller the number, the higher the durability.)

The second region in the protective layer preferably has an atomic ratio [oxygen / gallium] of 1.30 or more and 1.50 or less.
Within this range, the coloring of the second region is suppressed (that is, the transparency is improved), and the light transmittance in the wavelength region from ultraviolet to infrared (for example, the wavelength region of 350 nm or more and 800 nm or less) is increased. improves. As a result, the absorption of the light in the protective layer is suppressed when light is irradiated from the outside of the photoconductor in order to eliminate the charge of the charged electrophotographic photoconductor. Therefore, since the irradiated light efficiently reaches the photosensitive layer, the sensitivity of the electrophotographic photosensitive member is improved.
Furthermore, even if the atomic ratio [oxygen / gallium] in the second region is set to 1.30 or more and 1.50 or less, the first region exists on the side farther from the base than the second region. Therefore, the residual potential is suppressed as described above.

Further, it is desirable that the second region in the protective layer further contains zinc (Zn).
When the second region contains zinc, a decrease in sensitivity is further suppressed, and the residual potential is further suppressed.
About this cause, it is estimated that the charge transport property of the second region is improved by containing zinc in the second region. However, this embodiment is not limited by this cause.
From the viewpoint of suppressing the residual potential, the zinc content in the second region is preferably 0.4 atomic percent or more and 25 atomic percent or less, and more preferably 0.5 atomic percent or more and 20 atomic percent or less. It is particularly desirable that it is 10 atomic% or more and 20 atomic% or less.
Here, the zinc content in the second region is the ratio (%) of the number of zinc atoms to the total number of atoms when the second region is composed of gallium, oxygen, and zinc. .
Further, from the viewpoint of suppressing the decrease in sensitivity, the atomic ratio [oxygen / (gallium + zinc)] in the second region is preferably 1.00 or more and 1.40 or less.
Further, from the viewpoint of suppressing the decrease in sensitivity, the atomic ratio [zinc / gallium] in the second region is preferably 1.00 or less, more preferably 0.01 or more and 0.50 or less, It is particularly desirable that it is 0.20 or more and 0.50 or less.
From the viewpoint of suppressing the decrease in sensitivity, the zinc content in the second region is preferably 0.4 atomic% or more and 25 atomic% or less, and more preferably 0.5 atomic% or more and 20 atomic% or less. Desirably, it is 1 atomic% or more and 15 atomic% or less.

−Configuration of electrophotographic photosensitive member−
Hereinafter, the configuration of the electrophotographic photosensitive member according to the present embodiment will be described with reference to FIGS. 1 to 4, but the present embodiment is not limited to FIGS. 1 to 4.
FIG. 1 is a schematic cross-sectional view showing an example of the layer structure of the electrophotographic photosensitive member according to the present embodiment.
In FIG. 1, 1 is a substrate, 2 is a photosensitive layer, 2A is a charge generation layer, 2B is a charge transport layer, 3 is a protective layer, 3A is a first region, and 3B is a second region. 4 is an undercoat layer.
1 has a layer structure in which an undercoat layer 4, a charge generation layer 2A, a charge transport layer 2B, and a protective layer 3 are laminated in this order on a substrate 1, and the photosensitive layer 2 is a charge generation layer. 2A and the charge transport layer 2B.
The protective layer 3 includes a first region 3A existing on the outer peripheral surface side, and a second region 3B existing closer to the base 1 than the first region 3A.
In FIG. 1, for the sake of illustration, the boundary between the first region 3A and the second region 3B is clear (that is, the first region 3A is the first layer, and the second region 3B). Is the second layer), but this boundary is not limited to being clear. The same applies to the boundary between the first region 3A and the second region 3B in FIG. 2 and FIG. 3 and the boundary between the second region 3B and the third region 3C in FIG.

FIG. 2 is a schematic cross-sectional view showing another example of the layer configuration of the electrophotographic photosensitive member according to this embodiment. In FIG. 2, 6 represents a photosensitive layer, and the others are the same as those shown in FIG. It is the same.
2 has a layer structure in which an undercoat layer 4, a photosensitive layer 6, and a protective layer 3 are laminated in this order on a substrate 1, and the photosensitive layer 6 includes a charge generation layer 2A shown in FIG. In addition, the charge transport layer 2B has an integrated function.
The photosensitive layer 2 and the photosensitive layer 6 may be formed from an organic polymer, may be formed from an inorganic material, or may be a combination thereof.

FIG. 3 is a schematic cross-sectional view showing another example of the layer structure of the electrophotographic photosensitive member according to this embodiment. In FIG. 3, 3 is a protective layer, 3A is a first region, and 3B is a second. 3C represents the third region, and the others are the same as those shown in FIG.
3 has a layer structure in which an undercoat layer 4, a photosensitive layer 2, a third region 3C, a second region 3B, and a first region 3A are laminated in this order on a substrate 1. ing.
The protective layer 3 is closer to the base 1 than the first region 3A existing on the outer peripheral surface side, the second region 3B closer to the base 1 than the first region 3A, and the second region. And a third region 3C existing on the side.

FIG. 4 is a schematic cross-sectional view showing another example of the layer structure of the electrophotographic photosensitive member according to the present embodiment. In FIG. 4, 3 is a protective layer, 3D is a first layer, and 3E is a second layer. 3F represents an intermediate layer, and the others are the same as those shown in FIG.
The photoreceptor shown in FIG. 4 has a layer structure in which an undercoat layer 4, a photosensitive layer 2, a second layer 3E, an intermediate layer 3F, and a first layer 3D are laminated in this order on a substrate 1. .
The protective layer 3 includes a first layer 3D existing on the outer peripheral surface side, a second layer 3E existing closer to the substrate 1 than the first layer 3D, a first layer 3D, and a second layer 3E. The intermediate layer 3F exists between the two.
The photoreceptor shown in FIG. 4 may further have the above-described third region between the photosensitive layer 2 and the second layer 3E.

  Hereinafter, a protective layer, a photosensitive layer, and a substrate, which are components of the electrophotographic photosensitive member according to this embodiment, will be described.

-Protective layer-
As described above, the protective layer in this embodiment is a layer containing oxygen (O) and gallium (Ga), and is a layer provided further on the photosensitive layer provided on the substrate.
The protective layer, for example, suppresses scratches on the surface of the electrophotographic photoreceptor, suppresses polishing variations, suppresses adsorption of nitrogen oxides, and improves resistance to an oxidizing atmosphere caused by ozone or nitrogen oxides. It is a layer provided for the purpose. The protective layer is desirably a highly transparent and dense film with excellent hardness.
The protective layer in the present embodiment may trap surface charges on the surface or trap it inside. Further, a surface charge may be positively injected. In the case of injecting charges into the protective layer, it is desirable to have a configuration in which charges are trapped at the interface with the organic photosensitive layer. Further, when the surface layer injects electrons under negative charge, the surface of the hole transport layer may serve as a charge trapping function, or a layer for blocking and trapping charge injection may be provided. The same configuration is applied to the case of positive charging.

The protective layer is preferably a non-single crystal film such as a microcrystalline film, a polycrystalline film, or an amorphous film containing oxygen (O) and gallium (Ga).
Among these, amorphous is particularly desirable in terms of surface smoothness, but a microcrystalline film is more desirable in terms of hardness.
Furthermore, the growth cross section of the protective layer may have a columnar structure, but from the viewpoint of slipperiness, a structure with high flatness is desirable and amorphous is desirable.
In order to improve surface slipping while improving adhesion to the photosensitive layer, the region on the interface side with the photosensitive layer (for example, the second region) is a microcrystalline film, and the region on the surface side (for example, the first region) 1 region) may be an amorphous film.
The protective layer may further contain one or more elements selected from C, Si, Ge, and Sn, for example, in the case of n-type, in order to control the conductivity type. For example, in the case of p-type, it may contain one or more elements selected from N, Be, Mg, Ca, and Sr.

The protective layer preferably contains at least one of hydrogen and a halogen element in addition to oxygen (O) and gallium (Ga).
When the protective layer is microcrystalline, polycrystalline, or amorphous, there is a tendency for bond defects, dislocation defects, crystal grain boundary defects, etc. to increase, but by including hydrogen or a halogen element in the layer, This is desirable because the bonding defects are deactivated.
Hydrogen and halogen elements are taken into bond defects in the crystal and defects at the crystal grain boundaries, and perform electrical compensation. For this reason, the number of traps related to the generation of photocarriers, the diffusion and movement of carriers is reduced, the number of reactive sites is reduced, and a more stable protective layer is formed.
The content of “at least one of hydrogen and halogen elements” in the protective layer is preferably 5 atom% or more and 25 atom% or less, and more preferably 10 atom% or more and 25 atom% or less.

The content of hydrogen in the protective layer is determined by measuring an absolute value by hydrogen forward scattering (HFS), for example. Moreover, you may estimate by an infrared absorption spectrum.
HFS uses NEC 3SDH Pelletron as an accelerator, CE & A RBS-400 as an end station, and CE & A 3S-R10 as a system.
The analysis uses the CE & A HYPRA program.

The measurement conditions of HFS are as follows.
He ++ ion beam energy: 2.275 eV
A detection angle of 160 ° is Grazing Angle 30 ° with respect to the incident beam.

The HFS measurement picks up the hydrogen signal scattered in front of the sample by setting the detector at 30 ° to the He ++ ion beam and the sample at 75 ° from the normal. At this time, the detector is preferably covered with aluminum foil to remove He atoms scattered together with hydrogen. The quantification is performed by comparing the hydrogen counts of the reference sample and the sample to be measured after normalization with the stopping power. As a reference sample, a sample obtained by ion-implanting H into Si and muscovite are used.
It is known that muscovite has a hydrogen concentration of 6.5 atomic%.
The H adsorbed on the outermost surface is corrected by subtracting the amount of H adsorbed on the clean Si surface, for example.

--First region--
A 1st area | region is an area | region which exists in an outer peripheral surface side (side away from the support body) in the film thickness direction among protective layers.
The composition of the first region is not particularly limited, and examples thereof include a composition containing gallium and oxygen.
When the first region contains gallium and oxygen, the atomic ratio [O / Ga] is preferably 1.00 or more and less than 1.35, more preferably 1.10 or more and 1.30 or less. desirable.
In addition, the first region may contain hydrogen from the viewpoint of more effectively reducing the decrease in sensitivity of the photoreceptor.
The hydrogen content in the first region is preferably 5 atomic percent or more and 25 atomic percent or less, and more preferably 10 atomic percent or more and 25 atomic percent or less.
In addition, the desirable form of the first region is as described above as the desirable form of the protective layer.

As described above, the first region may contain an n-type element or a p-type element for controlling the conductivity type. In this case, the first region may be a charge injection blocking layer. Alternatively, a charge injection layer may be used. In the case of the charge injection layer, charges are trapped in the second region and the photosensitive layer surface.
In the case of negative charging, the n-type layer functions as a charge injection layer, and the p-type layer functions as a charge injection blocking layer. In the case of positive charging, the n-type layer functions as a charge injection blocking layer, and the p-type layer functions as a charge injection layer.

-Second region-
The second region is a region of the protective layer that is closer to the substrate than the first region, and has a larger atomic ratio [oxygen / gallium] than the first region.
As described above, the composition of the second region is a composition containing gallium and oxygen (and zinc if necessary).
The second region may further contain hydrogen from the viewpoint of more effectively reducing the decrease in sensitivity of the photoreceptor.
The hydrogen content in the second region is preferably 5 atomic percent or more and 25 atomic percent or less, and more preferably 10 atomic percent or more and 25 atomic percent or less.
In addition, the desirable form of the second region is as described above as the desirable form of the protective layer.

-Third area-
The third region is a region provided as necessary in the protective layer, and is a region that is closer to the substrate than the second region (preferably in contact with the photosensitive layer). This is a region where the atomic ratio [oxygen / gallium] is small.
The composition of the third region is not particularly limited, and examples thereof include a composition containing gallium and oxygen.
When the third region contains gallium and oxygen, the atomic ratio [O / Ga] is preferably 1.00 or more and less than 1.40, more preferably 1.10 or more and 1.35 or less. desirable.
Further, the third region may contain hydrogen from the viewpoint of more effectively reducing the decrease in sensitivity of the photoreceptor.
The hydrogen content in the third region is preferably 5 atomic percent or more and 25 atomic percent or less, and more preferably 10 atomic percent or more and 25 atomic percent or less.
In addition, the desirable form of the third region is as described above as the desirable form of the protective layer.

--Intermediate layer--
The intermediate layer is a layer provided as necessary in the protective layer, and when the protective layer includes the first layer and the second layer, between the first layer and the second layer, This is a layer provided with a composition in which the atomic ratio [oxygen / gallium] is not less than the atomic ratio [oxygen / gallium] of the first layer and not more than the atomic ratio [oxygen / gallium] of the second layer.
The composition of the intermediate layer is a composition containing gallium and oxygen (and zinc if necessary).
The intermediate layer may further contain hydrogen from the viewpoint of more effectively reducing the decrease in sensitivity of the photoreceptor.
The content of hydrogen in the intermediate layer is preferably 5 atomic percent or more and 25 atomic percent or less, and more preferably 10 atomic percent or more and 25 atomic percent or less.
In addition, the desirable form of the intermediate layer is as described above as the desirable form of the protective layer.

  In addition to the first region, the second region, the third region, and the intermediate layer, the protective layer may have other layers or regions as necessary.

-Method for forming protective layer-
Next, a method for forming the protective layer described above will be described.
For the formation of the protective layer, a known vapor deposition method such as a plasma CVD (Chemical Vapor Deposition) method, a metal organic vapor phase epitaxy method, a molecular beam epitaxy method, vapor deposition, or sputtering is used.

  FIG. 5 is a schematic diagram showing an example of a film forming apparatus used for forming the protective layer of the electrophotographic photosensitive member according to the present embodiment. FIG. 5A is a view of the film forming apparatus when viewed from the side. A schematic cross-sectional view is shown, and FIG. 5B is a schematic cross-sectional view taken along line A1-A2 of the film formation apparatus shown in FIG. In FIG. 5, 210 is a film forming chamber, 211 is an exhaust port, 212 is a substrate rotating unit, 213 is a substrate support member, 214 is a substrate, 215 is a gas introduction pipe, and 216 is a gas introduced from the gas introduction pipe 215. A shower nozzle having an opening for spraying, 217 is a plasma diffusion unit, 218 is a high-frequency power supply unit, 219 is a plate electrode, 220 is a gas introduction tube, and 221 is a high-frequency discharge tube unit.

In the film forming apparatus shown in FIG. 5, an exhaust port 211 connected to a vacuum exhaust device (not shown) is provided at one end of the film forming chamber 210, and the side on which the exhaust port 211 of the film forming chamber 210 is provided. On the opposite side, a plasma generator comprising a high frequency power supply unit 218, a plate electrode 219, and a high frequency discharge tube unit 221 is provided.
This plasma generator is arranged in a high frequency discharge tube portion 221, a high frequency discharge tube portion 221, a flat plate electrode 219 having a discharge surface provided on the exhaust port 211 side, a high frequency discharge tube portion 221 and a flat plate. The high-frequency power supply unit 218 is connected to the surface of the electrode 219 opposite to the discharge surface. The high-frequency discharge tube portion 221 is connected to a gas introduction tube 220 for supplying gas into the high-frequency discharge tube portion 221, and the other end of the gas introduction tube 220 is a first not shown. Connected to the gas supply.

  Note that the plasma generator shown in FIG. 6 may be used instead of the plasma generator provided in the deposition apparatus shown in FIG. FIG. 6 is a schematic diagram showing another example of the plasma generator used in the film forming apparatus shown in FIG. 5, and is a side view of the plasma generator. In FIG. 6, 222 is a high frequency coil, 223 is a quartz tube, and 220 is the same as that shown in FIG. This plasma generator is composed of a quartz tube 223 and a high-frequency coil 222 provided along the outer peripheral surface of the quartz tube 223, and one end of the quartz tube 223 is a film forming chamber 210 (not shown in FIG. 6). It is connected. A gas introduction tube 220 for introducing gas into the quartz tube 223 is connected to the other end of the quartz tube 223.

In FIG. 5, a rod-shaped shower nozzle 216 extending along the discharge surface is connected to the discharge surface side of the plate electrode 219, and one end of the shower nozzle 216 is connected to a gas introduction pipe 215. The introduction pipe 215 is connected to a second gas supply source (not shown) provided outside the film formation chamber 210.
In addition, a base material rotating unit 212 is provided in the film forming chamber 210 so that the cylindrical base material 214 faces the longitudinal direction of the shower nozzle 216 and the axial direction of the base material 214. It can be attached to the substrate rotating part 212 via the substrate support member 213. During film formation, the base material rotation unit 212 rotates, whereby the base material 214 rotates in the circumferential direction. As the base material 214, for example, a photosensitive member previously laminated up to the photosensitive layer, a photosensitive member laminated up to the second region on the photosensitive layer, and a photosensitive member laminated up to the third region on the photosensitive layer. Body, etc. are used.

The protective layer is formed as follows, for example.
First, oxygen gas (or helium (He) diluted oxygen gas), helium (He) gas, and hydrogen (H ₂ ) gas as needed are introduced into the high-frequency discharge tube portion 221 from the gas introduction tube 220, and A radio wave of 13.56 MHz is supplied from the high frequency power supply unit 218 to the plate electrode 219. At this time, the plasma diffusion portion 217 is formed so as to spread radially from the discharge surface side of the plate electrode 219 to the exhaust port 211 side. Here, the gas introduced from the gas introduction pipe 220 flows through the film forming chamber 210 from the plate electrode 219 side to the exhaust port 211 side. The plate electrode 219 may be one in which the electrode is surrounded by a ground shield.
Next, trimethylgallium gas is introduced into the film formation chamber 210 through a gas introduction pipe 215 and a shower nozzle 216 located downstream of the plate electrode 219 serving as an activating means, whereby gallium and oxygen are introduced into the surface of the substrate 214. A non-single-crystal film containing is formed.
As the substrate 214, for example, a substrate on which a photosensitive layer is formed is used.
When forming the second region containing zinc as the second region, for example, trimethylgallium gas and organic zinc (for example, dimethylzinc or diethyl) are used as the gas introduced from the gas introduction pipe 215. Zinc) gas. At this time, trimethylgallium and organic zinc are introduced into the gas introduction pipe 215 as gases from separate containers.

When the organic photoreceptor having the organic photosensitive layer is used, the temperature of the surface of the base material 214 when forming the protective layer is preferably 150 ° C. or lower, more preferably 100 ° C. or lower, and particularly preferably 30 ° C. or higher and 100 ° C. or lower. desirable.
Even if the temperature of the surface of the substrate 214 is 150 ° C. or less at the beginning of film formation, if the temperature is higher than 150 ° C. due to the influence of plasma, the organic photosensitive layer may be damaged by heat. Thus, it is desirable to control the surface temperature of the substrate 214.
Further, when an amorphous silicon photoconductor is used, the temperature of the surface of the base material 214 when the protective layer is formed is, for example, 30 ° C. or higher and 350 ° C. or lower.
The temperature of the surface of the substrate 214 may be controlled by heating and / or cooling means (not shown in the drawing), or may be left to a natural temperature increase during discharge. When heating the base material 214, a heater may be installed outside or inside the base material 214. When the substrate 214 is cooled, a cooling gas or liquid may be circulated inside the substrate 214.
In order to avoid an increase in the temperature of the surface of the base material 214 due to electric discharge, it is effective to adjust a high energy gas flow that strikes the surface of the base material 214. In this case, conditions such as the gas flow rate, discharge output, and pressure are adjusted so as to achieve the required temperature.

Further, instead of trimethylgallium gas, hydrides such as organometallic compounds containing aluminum and diborane may be used, and two or more of these may be mixed.
For example, in the initial stage of forming the protective layer, trimethylindium is introduced into the film formation chamber 210 through the gas introduction pipe 215 and the shower nozzle 216, thereby forming a film containing nitrogen and indium on the base material 214. In this case, the film absorbs ultraviolet rays that are generated when the film is continuously formed and deteriorate the photosensitive layer. For this reason, damage to the photosensitive layer due to generation of ultraviolet rays during film formation is suppressed.

Further, a dopant may be added to the protective layer in order to control its conductivity type.
As a dopant doping method during film formation, SiH ₃ and SnH ₄ are used for n-type, and biscyclopentadienylmagnesium, dimethylcalcium, dimethylstrontium, etc. are used in a gas state for p-type. . In order to dope the dopant element into the surface layer, a known method such as a thermal diffusion method or an ion implantation method may be employed.
Specifically, for example, by introducing a gas containing at least one dopant element into the film formation chamber 210 via the gas introduction pipe 215 and the shower nozzle 216, a conductive type such as n-type or p-type is used. Get a protective layer.

In the film formation apparatus described with reference to FIGS. 5 and 6, active nitrogen or active hydrogen formed by discharge energy may be controlled independently by providing a plurality of active apparatuses, or may be combined with nitrogen atoms such as NH _3. You may use the gas which contains a hydrogen atom simultaneously. Further, H ₂ may be added. Alternatively, conditions under which active hydrogen is liberated from an organometallic compound may be used.
By doing so, activated carbon atoms, gallium atoms, nitrogen atoms, hydrogen atoms, and the like exist on the surface of the base material 214 in a controlled state. Then, the activated hydrogen atom has an effect of desorbing hydrogen of a hydrocarbon group such as a methyl group or an ethyl group constituting the organometallic compound as a molecule.
For this reason, a hard film (protective layer) constituting a three-dimensional bond is formed.

The plasma generating means of the film forming apparatus shown in FIGS. 5 and 6 uses a high-frequency oscillator, but is not limited to this. For example, a microwave oscillator or an electrocyclotron resonance method is used. Alternatively, a helicon plasma type apparatus may be used. Further, in the case of a high-frequency oscillation device, it may be inductive or capacitive.
Furthermore, two or more of these devices may be used in combination, or two or more of the same types of devices may be used. In order to suppress the temperature rise on the surface of the substrate 214 by plasma irradiation, a high-frequency oscillation device is desirable, but a device for suppressing heat irradiation may be provided.

  When two or more different plasma generators (plasma generating means) are used, it is desirable that discharges are generated simultaneously at the same pressure. In addition, a pressure difference may be provided between the discharge area and the film formation area (the portion where the base is installed). These apparatuses may be arranged in series with respect to the gas flow formed in the film forming apparatus from the part where the gas is introduced to the part where the gas is discharged. You may arrange | position so that it may oppose.

For example, when two types of plasma generating means are installed in series with respect to the gas flow, the film forming apparatus shown in FIG. 5 is taken as an example, and a discharge is caused in the film forming chamber 210 using the shower nozzle 216 as an electrode. 2 is used as a plasma generator. In this case, for example, a high frequency voltage is applied to the shower nozzle 216 via the gas introduction pipe 215 to cause discharge in the film forming chamber 210 using the shower nozzle 216 as an electrode. Alternatively, instead of using the shower nozzle 216 as an electrode, a cylindrical electrode is provided between the base material 214 and the flat plate electrode 219 in the film forming chamber 210, and this film is used to form the film forming chamber. A discharge is caused in 210.
In addition, when two different types of plasma generators are used under the same pressure, for example, when using a microwave oscillator and a high-frequency oscillator, the excitation energy of the excited species can be greatly changed, and the film quality can be controlled. It is valid. Moreover, you may perform discharge by atmospheric pressure vicinity (70000 Pa or more and 110000 Pa or less). When discharging near atmospheric pressure, it is desirable to use He as a carrier gas.

In addition to the above-described methods, a normal metal organic vapor phase epitaxy method or a molecular beam epitaxy method is used for forming the surface layer or the like. However, in the film formation by these methods, active nitrogen and / or Use of active hydrogen and active oxygen is effective for lowering the temperature. In this case, as the nitrogen raw material, a gas or liquid such as N ₂ , NH ₃ , NF ₃ , N ₂ H ₄ , or methyl hydrazine is vaporized or bubbled with a carrier gas. As the oxygen raw material, oxygen, H ₂ O, CO, CO ₂ , NO, N ₂ O, or the like is used.

In the present embodiment, the protective layer is formed by, for example, installing a base material 214 having a photosensitive layer formed on a substrate in the film forming chamber 210 and introducing mixed gases having different compositions to form the second region, the first region. The region is continuously formed. If necessary, the third region is formed before the second region is formed. Further, an intermediate layer is formed between the second region and the first region as necessary.
Further, each region (or each layer) may be formed independently.

As film formation conditions, for example, when discharging is performed by high-frequency discharge, it is desirable that the frequency be in the range of 10 kHz to 50 MHz in order to perform high-quality film formation at a low temperature. Further, the output is dependent on the size of the substrate, it is desirable to 0.01 W / cm ² or more 0.2 W / cm ² or less in the range of the surface area of the substrate. The rotation speed of the substrate is desirably in the range of 0.1 rpm to 500 rpm.
The film formation conditions of each region (or each layer) may be the same. For example, the second region may be formed at a low temperature so that the output is low, and the first region may be formed with a high output. Good.

-Substrate and photosensitive layer-
The photosensitive layer is a layer provided between the substrate and the protective layer in the electrophotographic photosensitive member.
The electrophotographic photoreceptor according to the exemplary embodiment is not particularly limited as long as the layer configuration is such that a photosensitive layer and a protective layer are laminated in this order on a substrate, and if necessary, between the substrate and the photosensitive layer. An undercoat layer or the like may be provided. Further, the photosensitive layer may be two or more layers, and further may be a function separation type. Furthermore, the electrophotographic photoreceptor according to the present embodiment may be a so-called amorphous silicon photoreceptor in which the photosensitive layer contains silicon atoms.

In the case of an amorphous silicon photoreceptor, if the protective layer in the present embodiment is used as the surface layer portion, image blur at high humidity is suppressed, and both durability and high image quality are achieved.
In particular, the photosensitive layer is desirably a so-called organic photoreceptor containing an organic material such as an organic photosensitive material. In the case of an organic photoreceptor, wear is likely to occur. However, if the protective layer in this embodiment is used for the surface layer portion, wear is suppressed.

First, an outline of a desirable configuration when the electrophotographic photoreceptor is an organic photoreceptor will be described.
The organic polymer compound forming the photosensitive layer may be thermoplastic or thermosetting, or may be formed by reacting two types of molecules. The second region provided between the photosensitive layer and the first region is characterized by the physical properties of the first region and the photosensitive layer (functional separation) from the viewpoints of adjustment of hardness, expansion coefficient, elasticity, and adhesion. In the case of a mold, those showing intermediate characteristics with respect to both physical properties of the charge transport layer) are preferred. Further, the second region may function as a region for trapping charges.

  In the case of an organic photoreceptor, the photosensitive layer may be a function-separated type that is divided into a charge generation layer and a charge transport layer as shown in FIGS. 1, 3, and 4, or a functional layer as shown in FIG. It may be a figure. In the case of the function separation type, a charge generation layer may be provided on the surface side of the photoreceptor, or a charge transport layer may be provided on the surface side.

When the protective layer is formed on the photosensitive layer by the above-described method, in order to prevent the photosensitive layer from being decomposed by irradiation with short wavelength electromagnetic waves other than heat, the surface of the photosensitive layer is formed before the protective layer is formed. A short wavelength light absorption layer such as ultraviolet rays may be provided in advance. In addition, a layer having a small band gap may be formed first in the initial stage of forming the protective layer so that the short wavelength light is not irradiated onto the photosensitive layer. As the composition of the layer having a small band gap provided on the photosensitive layer side, for example, the group 13 element ratio including In is preferably Ga _X In _(1-X) (0 ≦ X ≦ 0.99).

Further, a layer containing an ultraviolet absorber (for example, a layer formed by coating a layer dispersed in a polymer resin) may be provided on the surface of the photosensitive layer.
As described above, by providing a layer containing an ultraviolet absorber on the surface of the photosensitive member before forming the protective layer, ultraviolet rays when forming the protective layer and corona when the photosensitive member is used in the image forming apparatus are used. The influence on the photosensitive layer due to short wavelength light such as electric discharge or ultraviolet rays from various light sources is reduced.

Next, an outline of a desirable configuration when the electrophotographic photoreceptor is an amorphous silicon photoreceptor will be described.
The amorphous silicon photoconductor may be a positively charged or negatively charged photoconductor.
For example, a substrate in which a charge injection blocking layer (undercoat layer), a photoconductive layer, and a charge injection blocking surface layer are provided in this order on a substrate is used.
The protective layer in this embodiment is formed on the charge injection blocking surface layer.

Further, as the uppermost layer (protective layer side layer) of the photosensitive layer, for example, a p-type amorphous silicon layer, an n-type amorphous silicon layer, Si _X O _1-X : H layer, Si _X N _1-X : H layer , Si _X C _1-X : H layer, amorphous carbon layer, and the like are used.

  Next, regarding the details of the substrate and the photosensitive layer constituting the electrophotographic photoreceptor and the details of the undercoat layer provided as necessary, the electrophotographic photoreceptor is an organic photoreceptor having a function-separated type photosensitive layer. Will be described.

-Substrate-
A conductive substrate is used as the substrate.
In this specification, “conductive” refers to the property of having a volume resistivity of less than 10 ¹³ Ω · cm, and “insulating” refers to the property of having a volume resistivity of 10 ¹³ Ω · cm or more. Point to.
Conductive substrates include metal drums such as aluminum, copper, iron, stainless steel, zinc, nickel; aluminum, copper, gold, silver, platinum, palladium, titanium, nickel on a substrate such as sheet, paper, plastic, glass, etc. -Deposited metal such as chromium, stainless steel, copper-indium; Deposited conductive metal compound such as indium oxide and tin oxide on the substrate; Laminated metal foil on the substrate; Carbon black Indium oxide, tin oxide-antimony oxide powder, metal powder, copper iodide, and the like are dispersed in a binder resin and applied to the substrate to conduct a conductive treatment. The shape of the substrate is preferably a cylindrical shape.

  When a metal pipe base is used as the conductive base, the surface of the metal pipe base may be a raw pipe, but the base surface may be roughened by surface treatment in advance. . Due to such roughening, when a coherent light source such as a laser beam is used as the exposure light source, grain-like density unevenness due to interference light that can be generated inside the photosensitive member is suppressed. Examples of the surface treatment method include mirror cutting, etching, anodizing, rough cutting, centerless grinding, sand blasting, wet honing and the like.

  In particular, it is desirable to use an anodized surface of the aluminum substrate as the conductive substrate in terms of improving adhesion to the photosensitive layer and improving film formability.

Hereinafter, a method for producing a conductive substrate having an anodized surface will be described.
First, pure aluminum or aluminum alloy (for example, alloy numbers 1000, 3000, and 6000 series aluminum or aluminum alloy defined in JISH4080) is prepared as a substrate. Next, an anodizing process is performed. The anodizing treatment is performed in an acidic bath of chromic acid, sulfuric acid, oxalic acid, phosphoric acid, boric acid, sulfamic acid, etc., and a treatment using a sulfuric acid bath is often used. The anodizing treatment is, for example, sulfuric acid concentration: 10 mass% to 20 mass%, bath temperature: 5 ° C. to 25 ° C., current density: 1 A / dm ^{2 to} 4 A / dm ² and electrolysis voltage: 5 V to 30 V. The treatment time is 5 to 60 minutes, but is not limited thereto.

  The anodized film formed on the aluminum substrate in this way is porous, has high insulating properties, and has a very unstable surface. Therefore, its physical properties change over time after the film is formed. It has become easier. In order to suppress the change in the physical property value, the anodized film is further subjected to a sealing treatment. Examples of the sealing treatment include a method of immersing the anodized film in an aqueous solution containing nickel fluoride and nickel acetate, a method of immersing the anodized film in boiling water, and a method of treating with pressurized steam. Of these methods, the method of immersing in an aqueous solution containing nickel acetate is most often used.

  On the surface of the anodic oxide film that has been subjected to the sealing treatment in this way, an excessive amount of metal salt or the like attached by the sealing treatment remains. If the metal salt or the like is excessively left on the anodic oxide film of the substrate, it not only adversely affects the quality of the coating film formed on the anodic oxide film, but generally tends to leave low resistance components. When an image is formed using this substrate as a photoconductor, it causes a background stain.

  Therefore, following the sealing process, an anodic oxide film is cleaned to remove metal salts and the like attached by the sealing process. The cleaning treatment may be performed by cleaning the substrate once with pure water, but it is desirable to clean the substrate by a multi-step cleaning process. At this time, for example, a deionized cleaning liquid is used as the cleaning liquid in the final cleaning step. Moreover, it is more desirable to perform physical rubbing cleaning using a contact member such as a brush in any one of the multi-step cleaning processes.

  The film thickness of the anodized film on the surface of the conductive substrate formed as described above is preferably in the range of about 3 μm to 15 μm. On the anodized film, there is a layer called a barrier layer along the porous extreme surface of the porous anodized film. The film thickness of the barrier layer is preferably in the range of 1 nm to 100 nm in the electrophotographic photosensitive member according to the present embodiment. As described above, an anodized conductive substrate is obtained.

  The conductive substrate thus obtained has a high carrier blocking property in the anodized film formed on the substrate by anodization. For this reason, point defects (black spots, background stains) that occur when reversal development (negative / positive development) is performed with a photoconductor using this conductive substrate mounted on an image forming apparatus are suppressed, and contact charging is performed. Current leakage from the contact charger, which sometimes occurs, is suppressed. In addition, by subjecting the anodized film to a sealing treatment, changes in the physical property values with time after the preparation of the anodized film are suppressed. Further, by cleaning the conductive substrate after the sealing treatment, the metal salt or the like attached to the surface of the conductive substrate is removed by the sealing treatment, and an image is provided with a photoconductor produced using this conductive substrate. When an image is formed by the apparatus, the occurrence of background stains is suppressed.

-Undercoat layer-
Next, the undercoat layer will be described. The material constituting the undercoat layer is acetal resin such as polyvinyl butyral; polyvinyl alcohol resin, casein, polyamide resin, cellulose resin, gelatin, polyurethane resin, polyester resin, methacrylic resin, acrylic resin, polyvinyl chloride resin, polyvinyl acetate In addition to polymer resin compounds such as resin, vinyl chloride-vinyl acetate-maleic anhydride resin, silicone resin, silicone-alkyd resin, phenol-formaldehyde resin, melamine resin, zirconium, titanium, aluminum, manganese, silicon atoms, etc. Examples thereof include organometallic compounds.
These compounds are used alone or as a mixture or polycondensate of a plurality of compounds. Among these, an organometallic compound containing zirconium or silicon is desirably used because it has a low residual potential and a small potential change due to the environment and a small potential change due to repeated use. In addition, the organometallic compound may be used alone or in combination of two or more, or may be used in combination with the above-described binder resin.

  As organosilane compounds (organometallic compounds containing silicon atoms), vinyltrimethoxysilane, γ-methacryloxypropyl-tris (β-methoxyethoxy) silane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane , Γ-glycidoxypropyltrimethoxysilane, vinyltriacetoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, N Examples include -β- (aminoethyl) -γ-aminopropylmethyldimethoxysilane, N, N-bis (β-hydroxyethyl) -γ-aminopropyltriethoxysilane, and γ-chloropropyltrimethoxysilane. Among these, vinyltriethoxysilane, vinyltris (2-methoxyethoxysilane), 3-methacryloxypropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxy Silane, N-2- (aminoethyl) 3-aminopropyltrimethoxysilane, N-2- (aminoethyl) 3-aminopropylmethyldimethoxysilane, 3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyl Silane coupling agents such as trimethoxysilane, 3-mercaptopropyltrimethoxysilane, and 3-chloropropyltrimethoxysilane are desirably used.

  In addition, as the undercoat layer, for example, a known undercoat layer such as the undercoat layer described in paragraphs 0113 to 0136 of JP-A-2008-075520 is used.

-Photosensitive layer: Charge transport layer-
Next, the photosensitive layer will be described below in this order, divided into a charge transport layer and a charge generation layer.
Examples of the charge transport material used for the charge transport layer include those shown below. That is, oxadiazole derivatives such as 2,5-bis (p-diethylaminophenyl) -1,3,4-oxadiazole, 1,3,5-triphenyl-pyrazoline, 1- [pyridyl- (2)]- Pyrazoline derivatives such as 3- (p-diethylaminostyryl) -5- (p-diethylaminostyryl) pyrazoline, triphenylamine, tri (p-methyl) phenylamine, N, N-bis (3,4-dimethylphenyl) biphenyl Aromatic tertiary amino compounds such as -4-amine, dibenzylaniline, 9,9-dimethyl-N, N-di (p-tolyl) fluorenon-2-amine, N, N′-diphenyl-N, N Aromatic tertiary diamino compounds such as' -bis (3-methylphenyl)-[1,1-biphenyl] -4,4'-diamine, 3- (4'-dimethylamino) 1,2,4-triazine derivatives such as phenyl) -5,6-di- (4′-methoxyphenyl) -1,2,4-triazine, 4-diethylaminobenzaldehyde-1,1-diphenylhydrazone, 4-diphenyl Aminobenzaldehyde-1,1-diphenylhydrazone, [p- (diethylamino) phenyl] (1-naphthyl) phenylhydrazone, 1-pyrenediphenylhydrazone, 9-ethyl-3-[(2methyl-1-indolinylimino) methyl Carbazole, 4- (2-methyl-1-indolinyliminomethyl) triphenylamine, 9-methyl-3-carbazole diphenylhydrazone, 1,1-di- (4,4′-methoxyphenyl) acrylaldehyde diphenylhydrazone , Β, β-bis (methoxyphenyl) vinyldiphenyl Hydrazone derivatives such as drazone, quinazoline derivatives such as 2-phenyl-4-styryl-quinazoline, benzofuran derivatives such as 6-hydroxy-2,3-di (p-methoxyphenyl) -benzofuran, p- (2,2-diphenyl) Hole transport materials such as α-stilbene derivatives such as vinyl) -N, N-diphenylaniline, enamine derivatives, carbazole derivatives such as N-ethylcarbazole, poly-N-vinylcarbazole and derivatives thereof are used. Or the polymer etc. which have the group containing the said compound in a principal chain or a side chain are mentioned. These charge transport materials are used alone or in combination of two or more.

  The binder resin used for the charge transport layer is not particularly limited, but it is desirable that the binder resin is particularly compatible with the charge transport material and has an appropriate strength.

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

  The molecular weight of the binder resin used for the charge transport layer is selected depending on the film thickness of the photosensitive layer and the film forming conditions such as a solvent, but it is usually preferably within a range of 3000 to 300,000 in terms of viscosity average molecular weight. The range of 200,000 or less is more desirable.

  The charge transport layer is formed by applying and drying a solution in which the charge transport material and the binder resin are dissolved in an appropriate solvent. Examples of the solvent used for forming the coating solution for forming the charge transport layer include aromatic hydrocarbons such as benzene, toluene and chlorobenzene, ketones such as acetone and 2-butanone, methylene chloride, chloroform and ethylene chloride. And halogenated aliphatic hydrocarbons, cyclic or linear ethers such as tetrahydrofuran, dioxane, ethylene glycol and diethyl ether, or a mixed solvent thereof. The blending ratio between the charge transport material and the binder resin is preferably within the range of 10: 1 to 1: 5. The layer thickness of the charge transport layer is generally preferably in the range of 5 μm to 50 μm, and more preferably in the range of 10 μm to 40 μm.

The charge transport layer and / or the charge generation layer, which will be described later, are used for the purpose of suppressing deterioration of the photoreceptor due to ozone, oxidizing gas, light, or heat generated in the image forming apparatus. Additives such as stabilizers may be included.
Examples of the antioxidant include hindered phenols, hindered amines, paraphenylenediamines, arylalkanes, hydroquinones, spirochromans, spiroidanones or their derivatives, organic sulfur compounds, and organic phosphorus compounds.

The charge transport layer is formed, for example, by applying a solution obtained by dissolving the charge transport material and the binder resin described above in an appropriate solvent and drying the solution. Examples of the solvent used for preparing the coating solution for forming the charge transport layer include aromatic hydrocarbons such as benzene, toluene and chlorobenzene, ketones such as acetone and 2-butanone, and halogens such as methylene chloride, chloroform and ethylene chloride. Cyclic aliphatic hydrocarbons, cyclic or linear ethers such as tetrahydrofuran, dioxane, ethylene glycol and diethyl ether, or a mixed solvent thereof is used.
Silicone oil may be added to the charge transport layer forming coating solution as a leveling agent for improving the smoothness of the coating film to be coated and formed.

  The compounding ratio of the charge transport material and the binder resin is desirably 10: 1 to 1: 5 by mass ratio. The layer thickness of the charge transport layer is generally preferably in the range of 5 μm to 50 μm, and more preferably in the range of 10 μm to 30 μm.

  The coating solution for forming the charge transport layer can be applied by dip coating, ring coating, spray coating, bead coating, blade coating, roller coating, knife coating, curtain coating, depending on the shape and application of the photoreceptor. This is performed using a coating method such as a coating method. As for drying, it is desirable to heat-dry after touch drying at room temperature (for example, 20 ° C. or higher and 30 ° C. or lower). The heat drying is desirably performed in a temperature range of 30 ° C. or higher and 200 ° C. or lower for a time in the range of 5 minutes to 2 hours.

  In addition, as the charge transport layer, for example, a known charge transport layer such as a charge transport layer described in paragraphs 0137 to 0150 of JP-A-2008-075520 is used.

-Photosensitive layer: Charge generation layer-
The charge generation layer is formed by depositing a charge generation material by a vacuum deposition method or by applying a solution containing an organic solvent and a binder resin.

Examples of charge generation materials include amorphous selenium, crystalline selenium, selenium-tellurium alloy, selenium-arsenic alloy, and other selenium compounds; inorganic photoconductors such as selenium alloy, zinc oxide, and titanium oxide; Sensitized, various phthalocyanine compounds such as metal-free phthalocyanine, titanyl phthalocyanine, copper phthalocyanine, tin phthalocyanine, gallium phthalocyanine; Various organic pigments such as salts; or dyes are used.
In addition, these organic pigments generally have several types of crystals. In particular, phthalocyanine compounds have various crystal types including α type and β type. Any of these crystal forms may be used as long as it is a pigment capable of obtaining characteristics.

  Of the charge generation materials described above, phthalocyanine compounds are desirable. In this case, when the photosensitive layer is irradiated with light, the phthalocyanine compound contained in the photosensitive layer absorbs photons and generates carriers. At this time, since the phthalocyanine compound has high quantum efficiency, the absorbed photons are efficiently absorbed to generate carriers.

Further, among the phthalocyanine compounds, phthalocyanines shown in the following (1) to (3) are more preferable. That is,
(1) At least 7.6 °, 10.0 °, 25.2 °, 28.0 ° in the Bragg angle (2θ ± 0.2 °) of the X-ray diffraction spectrum using Cukα rays as the charge generation material Crystalline hydroxygallium phthalocyanine having a diffraction peak at the position.
(2) At least 7.3 °, 16.5 °, 25.4 °, 28.1 ° in the Bragg angle (2θ ± 0.2 °) of the X-ray diffraction spectrum using Cukα rays as the charge generation material Crystalline chlorogallium phthalocyanine having a diffraction peak at the position.
(3) Diffraction peaks at positions of at least 9.5 °, 24.2 °, and 27.3 ° in the Bragg angle (2θ ± 0.2 °) of the X-ray diffraction spectrum using Cukα rays as the charge generation material. A crystalline form of titanyl phthalocyanine.

  Since these phthalocyanine compounds have not only high photosensitivity but also high stability of photosensitivity, a photoreceptor having a photosensitive layer containing these phthalocyanine compounds is required to have high-speed image formation and reproducibility. It is suitable as a photoreceptor for a color image forming apparatus.

  Note that the peak intensity and position may slightly deviate from these values depending on the crystal shape and measurement method. However, if the X-ray diffraction patterns are basically the same, the same crystal type is assumed. To be judged.

Examples of the binder resin used for the charge generation layer include the following.
Namely, polycarbonate resin such as bisphenol A type or bisphenol Z type and copolymers thereof, polyarylate resin, polyester resin, methacrylic resin, acrylic resin, polyvinyl chloride resin, polystyrene resin, polyvinyl acetate resin, styrene-butadiene copolymer Resin, vinylidene chloride-acrylonitrile copolymer resin, vinyl chloride-vinyl acetate-maleic anhydride resin, silicone resin, silicone-alkyd resin, phenol-formaldehyde resin, styrene-alkyd resin, poly-N-vinylcarbazole, etc. .

  These binder resins are used alone or in combination of two or more. The mixing ratio of the charge generation material and the binder resin (charge generation material: binder resin) is preferably in the range of 10: 1 to 1:10 by mass ratio. In general, the thickness of the charge generation layer is desirably in the range of 0.01 μm to 5 μm, and more desirably in the range of 0.05 μm to 2.0 μm.

The charge generation layer may contain at least one electron accepting substance for the purpose of improving sensitivity, reducing residual potential, reducing fatigue during repeated use, and the like. Examples of the electron accepting material used in the charge generation layer include succinic anhydride, maleic anhydride, dibromomaleic anhydride, phthalic anhydride, tetrabromophthalic anhydride, tetracyanoethylene, tetracyanoquinodimethane, o-dinitrobenzene. M-dinitrobenzene, chloranil, dinitroanthraquinone, trinitrofluorenone, peak phosphoric acid, o-nitrobenzoic acid, p-nitrobenzoic acid, phthalic acid and the like. Of these, fluorenone-based, quinone-based, and benzene derivatives having electron-withdrawing substituents such as Cl, CN, NO ₂ are particularly preferable.

As a method for dispersing the charge generating material in the resin, methods such as a roll mill, a ball mill, a vibrating ball mill, an attritor, a dyno mill, a sand mill, and a colloid mill are used.
Known organic solvents as coating solution solvents for forming the charge generation layer, for example, aromatic hydrocarbon solvents such as toluene and chlorobenzene, fats such as methanol, ethanol, n-propanol, iso-propanol, and n-butanol Aromatic alcohol solvents, ketone solvents such as acetone, cyclohexanone and 2-butanone, halogenated aliphatic hydrocarbon solvents such as methylene chloride, chloroform and ethylene chloride, cyclic or straight chain such as tetrahydrofuran, dioxane, ethylene glycol and diethyl ether And ether solvents such as methyl ether, methyl acetate, ethyl acetate, and n-butyl acetate.

  These solvents are used alone or in combination of two or more. When two or more kinds of solvents are mixed and used, for example, a solvent that dissolves the binder resin is used as the mixed solvent. However, when the photosensitive layer has a layer structure in which the charge transport layer and the charge generation layer are formed in this order from the conductive substrate side, charge generation is performed using a coating method that easily dissolves the lower layer, such as dip coating. When forming the layer, it is desirable to use a solvent that does not dissolve the lower layer such as the charge transport layer. In addition, when the charge generation layer is formed by using a spray coating method or a ring coating method with a relatively low erosion property of the lower layer, the selection range of the solvent is widened.

(Charging device)
Examples of the charging device 20 include a contact charger using a conductive charging roller, a charging brush, a charging film, a charging rubber blade, a charging tube, and the like. Further, examples of the charging device 20 include a non-contact type roller charger and a known charger such as a scorotron charger using a corona discharge or a corotron charger. The charging device 20 is preferably a contact type charger.

(Exposure equipment)
Examples of the exposure apparatus 30 include optical system devices that expose the surface of the electrophotographic photoreceptor 10 with light such as semiconductor laser light, LED light, and liquid crystal shutter light imagewise. The wavelength of the light source is preferably within the spectral sensitivity region of the electrophotographic photoreceptor 10. As the wavelength of the semiconductor laser, for example, near infrared having an oscillation wavelength around 780 nm is preferable. However, the present invention is not limited to this wavelength, and a laser having an oscillation wavelength of 600 nm or a laser having an oscillation wavelength of 400 nm to 450 nm as a blue laser may be used. Further, as the exposure apparatus 30, for example, a surface emitting laser light source of a multi-beam output type is also effective for color image formation.

(Developer)
The developing device 40 is disposed, for example, opposite to the electrophotographic photoreceptor 10 in the developing region, and includes, for example, a developing container 41 (developing device main body) that contains a two-component developer composed of toner and a carrier, and a replenishment device. A developer storage container (toner cartridge) 47. The developing container 41 includes a developing container main body 41A and a developing container cover 41B that closes the upper end thereof.

  The developing container main body 41A has, for example, a developing roll chamber 42A that accommodates the developing roll 42 therein, and is adjacent to the first stirring chamber 43A and the first stirring chamber 43A adjacent to the developing roll chamber 42A. Second agitating chamber 44A. Further, in the developing roll chamber 42A, for example, a layer thickness regulating member 45 for regulating the layer thickness of the developer on the surface of the developing roll 42 is provided when the developing container cover 41B is attached to the developing container main body 41A. Yes.

  The first stirring chamber 43A and the second stirring chamber 44A are partitioned by, for example, a partition wall 41C. Although not shown, the first stirring chamber 43A and the second stirring chamber 44A are arranged in the longitudinal direction of the partition wall 41C (developing device). (Longitudinal direction) Openings are provided at both ends, and the circulation stirring chamber (43A + 44A) is constituted by the first stirring chamber 43A and the second stirring chamber 44A.

  The developing roll 42 is disposed in the developing roll chamber 42 </ b> A so as to face the electrophotographic photoreceptor 10. Although not shown, the developing roll 42 is provided with a sleeve outside a magnetic roll (fixed magnet) having magnetism. The developer in the first stirring chamber 43A is adsorbed on the surface of the developing roll 42 by the magnetic force of the magnetic roll and is transported to the developing area. Further, the developing roller 42 has a roll shaft supported rotatably on the developing container main body 41A. Here, the developing roll 42 and the electrophotographic photoreceptor 10 rotate in the same direction, and the developer adsorbed on the surface of the developing roll 42 at the opposite portion is opposite to the traveling direction of the electrophotographic photoreceptor 10. It is conveyed from the direction to the development area.

  Further, a bias power source (not shown) is connected to the sleeve of the developing roll 42 so that a developing bias is applied (in this embodiment, a direct current component is applied so that an alternating electric field is applied to the developing region. (A bias in which an alternating current component (DC) is superimposed on (AC) is applied).

  In the first stirring chamber 43A and the second stirring chamber 44A, a first stirring member 43 (stirring / conveying member) and a second stirring member 44 (stirring / conveying member) that convey the developer while stirring are disposed. The first stirring member 43 includes a first rotating shaft that extends in the axial direction of the developing roll 42, and an agitating / conveying blade (protrusion) that is helically fixed to the outer periphery of the rotating shaft. Similarly, the second agitating member 44 includes a second rotating shaft and an agitating / conveying blade (protrusion). The stirring member is rotatably supported by the developing container main body 41A. The first stirring member 43 and the second stirring member 44 are arranged such that the developer in the first stirring chamber 43A and the second stirring chamber 44A is conveyed in the opposite directions by rotation thereof. .

  One end of a replenishment conveyance path 46 for supplying replenishment developer including replenishment toner and replenishment carrier to the second agitation chamber 44A is connected to one end side in the longitudinal direction of the second agitation chamber 44A. The other end of the replenishment conveyance path 46 is connected to a replenishment developer storage container 47 that contains a replenishment developer.

  In this manner, the developing device 40 supplies the replenishment developer from the replenishment developer storage container (toner cartridge) 47 to the development device 40 (second stirring chamber 44A) through the replenishment conveyance path 46.

Here, the developer used in the developing device 40 will be described.
As the developer, a two-component developer including a toner and a carrier is employed.

First, the toner will be described.
The toner includes, for example, toner particles containing a binder resin, a colorant, and, if necessary, other additives such as a release agent, and external additives as necessary.

The toner particles have an average shape factor (shape factor = (ML ² / A) × (π / 4) × 100), and ML represents the maximum length of the particles, where A represents the maximum length of the particles (Representing the projected area) is preferably from 100 to 150, more preferably from 105 to 145, and even more preferably from 110 to 140. Further, the toner preferably has a volume average particle diameter of 3 μm or more and 12 μm or less, more preferably 3.5 μm or more and 10 μm or less, and further preferably 4 μm or more and 9 μm or less.

  The toner particles are not particularly limited by the production method, and for example, a kneading and pulverizing method in which a binder resin, a colorant and a release agent, and a charge control agent and the like are added, if necessary, are kneaded, pulverized, and classified; A method of changing the shape of the particles obtained by the kneading and pulverization method by mechanical impact force or thermal energy; the polymerization monomer of the binder resin is emulsion-polymerized, the formed dispersion, the colorant and the release agent Emulsion polymerization aggregation method to obtain a toner particle by mixing a mold agent and, if necessary, a dispersion of a charge control agent, and agglomerating and heat-fusing; a polymerizable monomer for obtaining a binder resin, and coloring Suspension polymerization method in which a solution of an agent, a release agent and, if necessary, a charge control agent is suspended in an aqueous solvent for polymerization; a binder resin, a colorant and a release agent, and if necessary, a charge control agent Toner particles produced by a solution suspension method in which a solution such as a liquid is suspended in an aqueous solvent and granulated There will be used.

  Further, a known method such as a production method in which the toner particles obtained by the above method are used as a core, and agglomerated particles are further adhered and heated and fused to give a core-shell structure is used. The toner production method is preferably a suspension polymerization method, an emulsion polymerization aggregation method, or a dissolution suspension method in which an aqueous solvent is used from the viewpoint of shape control and particle size distribution control, and an emulsion polymerization aggregation method is particularly desirable.

  The toner is produced by mixing the toner particles and the external additive with a Henschel mixer or a V blender. Further, when the toner particles are produced by a wet method, they may be externally added by a wet method.

  On the other hand, as the carrier, iron powder, glass beads, ferrite powder, nickel powder, or the like coated with a resin is used. Further, the mixing ratio of the carrier and the toner is not particularly limited and is set within a known range.

(Transfer device)
Examples of the primary transfer device 51 and the secondary transfer device 52 include a contact transfer charger using a belt, a roller, a film, a rubber blade, and the like, a scorotron transfer charger using a corona discharge, a corotron transfer charger, and the like. A transfer charger known per se can be used.

  As the intermediate transfer member 50, a belt-like member (intermediate transfer belt) such as polyimide, polyamideimide, polycarbonate, polyarylate, polyester, rubber containing a conductive agent is used. Further, as the form of the intermediate transfer member, a cylindrical one is used in addition to the belt shape.

(Charge injection suppression material supply device)
The charge injection suppressing material supply device 60 is provided, for example, inside the cleaning device 70 and upstream of the cleaning blade 72 in the rotation direction of the electrophotographic photosensitive member 10.

  Examples of the charge injection suppressing material supply device 60 include a rotating brush 61 disposed in contact with the electrophotographic photosensitive member 10 and a solid charge injection suppressing material 62 disposed in contact with the rotating brush 61. It is configured. In the charge injection suppressing material supply device 60, the rotating brush 61 is rotated in contact with the solid charge injection suppressing material 62, whereby the charge injection suppressing material 62 adheres to the rotating brush 61 and the attached charge injection. The suppression material 62 is supplied to the surface of the electrophotographic photosensitive member 10, and a film of the charge injection suppression material 62 is formed.

  Note that the charge injection suppression material supply device 60 is not limited to the above-described form, and may be, for example, a form in which a rubber roller is used instead of the rotating brush 61.

Examples of the charge injection suppressing material 62 include a material having a volume resistivity of 10 ¹² Ωcm or more.
The volume resistivity was measured according to JIS-K-6911 (1995) by using a circular electrode (high probe IP UR probe manufactured by Mitsubishi Yuka Co., Ltd .: cylindrical electrode outer diameter Φ16 mm, ring-shaped electrode part) Is measured by using a microammeter R8340A manufactured by Advantest and applying a voltage of 100V under an environment of 22 ° C / 55% RH and applying a voltage of 5 sec after application. Thus, the volume resistivity is obtained from the volume resistance.

Specific examples of the charge injection suppressing material 62 include molybdenum disulfide and a fatty acid metal salt.
Examples of the fatty acid metal salt include fatty acids (for example, stearic acid, 12-hydroxystearic acid, behenic acid, montanic acid, lauric acid, other organic acids and the like, and calcium, zinc, magnesium, aluminum, and others (Na, A metal salt with a metal such as Li).
Specific examples of the fatty acid metal salt include zinc stearate, calcium stearate, iron stearate, copper stearate, magnesium palmitate, calcium palmitate, manganese oleate, and lead oleate.

  As the charge injection suppressing material 62, a fatty acid metal salt is preferable because it has a small effect on the image forming ability (for example, electrostatic latent image forming ability) of the electrophotographic photosensitive member 10 as well as suppressing the charge injection of the electrophotographic photosensitive member 10. Particularly preferred is zinc stearate.

On the other hand, examples of the fibers of the rotating brush 61 include resin fibers such as nylon, acrylic, polypropylene, and polyester.
The rotating brush 61 has, for example, a fiber density of 15 × 10 ³ / inch ² or more and 120 × 10 ³ / inch ² or less (23.4 / mm ² or more and 186 / mm ² or less), fiber length. Is 1.0 mm to 7.0 mm, and the fiber thickness is 0.5 denier to 30 denier.
The amount of fibers entering the surface of the electrophotographic photosensitive member 10 in the rotary brush 61 is preferably 0.3 mm or more and 1.5 mm or less, for example.
The rotational speed of the rotary brush 61 is preferably changed according to the peripheral speed of the electrophotographic photosensitive member 10. For example, the relative speed ratio with respect to the electrophotographic photosensitive member 10 is 0.5 to 1.5. Good. Further, the rotation direction of the rotating brush 61 may be the same as or opposite to the rotation direction of the electrophotographic photosensitive member 10.
Although not shown, a plate-like member that mechanically knocks off the toner adhering to the rotating brush 61 may be provided.

  Here, the supply amount of the charge injection suppressing material 62 by the rotating brush 61 is, for example, the fiber density, the fiber length, the fiber thickness and the fiber material of the surface of the rotating brush 61, the rotation speed of the rotating brush 61, and the like. It is adjusted by adjusting. Further, the supply amount of the charge injection suppressing material 62 may be adjusted by changing the pressing pressure between the charge injection suppressing material 62 and the rotating brush 61. Further, a mechanism for contacting and separating the charge injection suppressing material 62 and the rotating brush 61 is provided, and the supply amount of the charge injection suppressing material 62 is adjusted even if the contact time between the charge injection suppressing material 62 and the rotating brush 61 is controlled. Also good.

(Cleaning device)
The cleaning device 70 includes a housing 71 and a cleaning blade 72 disposed so as to protrude from the housing 71. The cleaning blade 72 is a plate-like member extending in a direction along the rotation axis of the electrophotographic photosensitive member 10, and the tip portion applies pressure upstream of the rotation direction (arrow a) of the electrophotographic photosensitive member 10. It is provided so that it contacts while hanging.

  The cleaning blade 72 removes untransferred residual toner remaining on the electrophotographic photosensitive member 10 without being transferred onto the recording paper P by the primary transfer device 51 by rotating the electrophotographic photosensitive member 10 in the direction of arrow a.

  Here, examples of the material of the cleaning blade 72 include known materials, such as urethane rubber, silicon rubber, fluorine rubber, chloroprene rubber, and butadiene rubber. Among these, polyurethane rubber is particularly preferable.

  Next, the operation of the image forming apparatus 101 according to the present embodiment will be described. First, the electrophotographic photoreceptor 10 rotates along the direction indicated by the arrow a, and at the same time is negatively charged by the charging device 20.

  The electrophotographic photoreceptor 10 whose surface is negatively charged by the charging device 20 is exposed by the exposure device 30, and a latent image is formed on the surface.

  When the portion where the latent image is formed on the electrophotographic photoreceptor 10 approaches the developing device 40, the developing device 40 (developing roll 42) attaches toner to the latent image and forms a toner image.

  When the electrophotographic photosensitive member 10 on which the toner image is formed further rotates in the direction of arrow a, the toner image is transferred to the outer surface of the intermediate transfer member 50.

  When the toner image is transferred to the intermediate transfer member 50, the recording paper P is supplied to the secondary transfer device 52 by the recording paper supply device 53, and the toner image transferred to the intermediate transfer member 50 is transferred by the secondary transfer device 52. Transferred onto the recording paper P. As a result, a toner image is formed on the recording paper P.

  The toner image is fixed on the recording paper P on which the image is formed by the fixing device 80.

  Here, after the toner image is transferred to the intermediate transfer member 50, the electrophotographic photosensitive member 10 is transferred, and then the charge injection suppressing material supply device 60 supplies the charge injection suppressing material 62 to the surface of the electrophotographic photosensitive member 10. Thus, a film of the charge injection suppressing material 62 is formed on the surface of the electrophotographic photoreceptor 10. Thereafter, the toner remaining on the surface is removed by the cleaning blade 72 of the cleaning device 70. Then, the electrophotographic photosensitive member 10 from which the transfer residual toner is removed in the cleaning device 70 is charged again by the charging device 20 and is exposed in the exposure device 30 to form a latent image.

  In the image forming apparatus 101 according to the present embodiment, the configuration in which the charge injection suppression material supply device 60 for supplying the charge injection suppression material 62 is described. However, the present invention is not limited to this, and the charge injection suppression material supply device 60 is provided. Without being provided, the powder of the charge injection suppressing material 62 is applied as an external additive of the toner, and the charge injection suppressing material 62 is supplied to the surface of the electrophotographic photoreceptor 10 together with the development by the developing device 40 (that is, the developing device 40). May also serve as the charge injection suppressing material supply device 60).

Further, for example, as illustrated in FIG. 8, the image forming apparatus 101 according to the present embodiment includes an electrophotographic photosensitive member 10, a charging device 20, a developing device 40, a charge injection suppressing material supply device 60, in a housing 11. In addition, the configuration may include a process cartridge 101A in which the cleaning device 70 is accommodated integrally. The process cartridge 101A integrally contains a plurality of members and is attached to and detached from the image forming apparatus 101. In the image forming apparatus 101 shown in FIG. 8, the developing device 40 is not provided with the replenishment developer storage container 47.
The configuration of the process cartridge 101A is not limited to this. For example, it is sufficient that the process cartridge 101A includes at least the electrophotographic photosensitive member 10 and the charge injection suppressing material supply device 60. In addition, for example, the charging device 20, the exposure device 30, and the development At least one selected from the device 40, the primary transfer device 51, and the cleaning device 70 may be provided.

  In addition, the image forming apparatus 101 according to the present embodiment is not limited to the above-described configuration. For example, the cleaning is performed around the electrophotographic photosensitive member 10 and downstream of the primary transfer device 51 in the rotation direction of the electrophotographic photosensitive member 10. A first neutralization device may be provided on the upstream side of the rotation direction of the electrophotographic photosensitive member relative to the device 70 so that the polarity of the remaining toner is aligned and easily removed with a cleaning brush. Even if the second static eliminating device for neutralizing the surface of the electrophotographic photosensitive member 10 is provided on the downstream side in the rotational direction of the electrophotographic photosensitive member relative to the upstream side in the rotational direction of the electrophotographic photosensitive member relative to the charging device 20. Good.

  Further, the image forming apparatus 101 according to the present embodiment is not limited to the above-described configuration, and may employ a known configuration, for example, a method of directly transferring a toner image formed on the electrophotographic photosensitive member 10 to the recording paper P. Alternatively, a tandem image forming apparatus may be employed.

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. In the following examples, “part” means part by mass.

[Electrophotographic photoreceptor 1]
First, an organic photoreceptor was produced by laminating an undercoat layer, a charge generation layer, and a charge transport layer in this order on an aluminum (Al) substrate by the procedure described below.

<Formation of undercoat layer>
20 parts by mass of a zirconium compound (trade name: Organotix ZC540 manufactured by Matsumoto Pharmaceutical Co., Ltd.), 2.5 parts by mass of a silane compound (trade name: A1100 manufactured by Nippon Unicar Co., Ltd.), a polyvinyl butyral resin (trade name: S-REC BM- manufactured by Sekisui Chemical Co., Ltd.) S) A solution obtained by stirring and mixing 10 parts by mass and 45 parts by mass of butanol was applied to the surface of an Al substrate having an outer diameter of 84 mm, and dried by heating at 150 ° C. for 10 minutes, whereby the layer thickness was 1.0 μm. A layer was formed.

<Formation of charge generation layer>
Next, a mixture obtained by mixing 1 part by mass of chlorogallium phthalocyanine as a charge generation material with 1 part by mass of polyvinyl butyral (trade name: S-REC BM-S manufactured by Sekisui Chemical Co., Ltd.) and 100 parts by mass of n-butyl acetate. Dispersion with a glass bead with a paint shaker for 1 hour gave a dispersion for forming a charge generation layer.
This dispersion was applied on the undercoat layer by the dipping method and then dried at 100 ° C. for 10 minutes to form a charge generation layer having a layer thickness of 0.15 μm.

<Formation of charge transport layer>
Next, 2 parts by mass of a compound represented by the following structural formula (1) and 3 parts by mass of a polymer compound (viscosity average molecular weight: 39000) whose repeating unit is represented by the following structural formula (2) are mixed with chlorobenzene 20 A charge transport layer forming coating solution was obtained by dissolving in mass parts.

  This coating solution is applied onto the charge generation layer by an immersion method, heated at 110 ° C. for 40 minutes to form a charge transport layer having a layer thickness of 20 μm, and the undercoat layer, the charge generation layer and the charge transport layer are formed on the Al substrate. As a result, an organic photoreceptor (hereinafter sometimes referred to as “non-coated photoreceptor (1)”) in which layers were formed in this order was obtained.

<Formation of protective layer>
(Formation of second layer)
Formation of the second layer on the surface of the non-coated photoreceptor (1) was performed using a film forming apparatus having the configuration shown in FIG.
First, the non-coated photoreceptor (1) is placed on the base material support member 213 in the film forming chamber 210 of the film forming apparatus, and the inside of the film forming chamber 210 is vacuumed through the exhaust port 211 until the pressure becomes 0.1 Pa. Exhausted.
Next, He-diluted 20% oxygen gas (20 sccm), He gas (100 sccm), and H ₂ gas (500 sccm) are fed from the gas introduction tube 220 into the high-frequency discharge tube portion 221 provided with the lithographic electrode 219 having a diameter of 50 mm. Then, a 13.56 MHz radio wave was set to an output of 100 W by a high frequency power supply unit 218 and a matching circuit (not shown in FIG. 6), matching was performed with a tuner, and discharge was performed from the lithographic electrode 219. The reflected wave at this time was 0 W.
Next, trimethylgallium gas (3 sccm) was introduced from the shower nozzle 216 to the plasma diffusion portion 217 in the film formation chamber 210 via the gas introduction tube 215. At this time, the reaction pressure in the film forming chamber 210 measured with a Baratron vacuum gauge was 40 Pa.

  In this state, the non-coated photoconductor (1) was formed for 120 minutes while rotating at a speed of 100 rpm, and a second layer having a thickness of 3.5 μm was formed on the surface of the charge transport layer of the non-coated photoconductor (1).

(Formation of the first layer)
Next, high frequency discharge was stopped, the flow rate of He diluted 20% oxygen gas was changed to 1 sccm, and then high frequency discharge was started again.
In this state, the non-coated photoreceptor (1) on which the second layer is formed is formed for 30 minutes while rotating at a speed of 100 rpm, and a first layer having a layer thickness of 0.3 μm is formed on the second layer. did.

Thus, an electrophotographic photosensitive member (electrophotographic photosensitive member with a protective layer) having the second layer and the first layer in this order as protective layers on the charge transport layer of the non-coated photosensitive member (1) was obtained.
It should be noted that when the protective layer (second layer and first layer) was formed, the non-coated photoreceptor (1) was not heat-treated. In addition, in order to monitor the temperature at the time of film formation, the color of the temperature measurement sticker (made by Wahl, Temp Plate P / N101) previously attached to the surface of the non-coated photoreceptor before film formation is It was 45 degreeC when it confirmed after film-forming of 1 layer.
Moreover, the layer thickness of the first layer and the layer thickness of the second layer were obtained by measuring the stylus step using the following sample film for analysis.
As a substrate on which the sample film for analysis was formed, a Si wafer having a thickness of 400 μm cut into 5 mm × 10 mm was used.
A polyimide adhesive tape is applied to a part of the surface of the Si wafer, and the sample film for analysis of the first layer is formed on the surface on which the adhesive tape is attached under the same conditions as the film formation of the first layer. Formed.
Next, the adhesive tape was peeled off, and a non-film-formed part (location where the adhesive tape was applied) and a film-attached part (location where the adhesive tape was not applied) were provided on the Si wafer surface.
Next, the level difference between the non-film-deposited part and the film-deposited part was measured with a stylus level measuring device (Surfcom 550A manufactured by Tokyo Seimitsu Co., Ltd.) to determine the layer thickness of the first layer.
The layer thickness of the second layer was also determined by the same method as the layer thickness of the first layer.

(Analysis and evaluation of the first layer)
A sample film for analysis was formed on a Si substrate having a thickness of 300 μm under the same conditions as those for forming the first layer.
About the formed 1st layer (sample film | membrane), the composition of the film | membrane was measured using Rutherford back scattering (RBS) and hydrogen forward scattering (HFS).
The atomic ratio [O / Ga] and the hydrogen content (ratio of the number of H atoms to the total number of atoms of Ga, O, and H; atomic%) were as shown in Table 1.
In addition, in the diffraction image obtained by RHEED (reflection high-energy electron diffraction) measurement, no dots or lines were found, and it was found that the first layer was amorphous.
Further, the surface of the first layer (sample film) was not damaged even when rubbed with stainless steel.

Next, a sample film was formed on a quartz substrate having a thickness of 0.5 mm under the same conditions as those for forming the first layer, and when the coloration was confirmed visually, the first layer was colored light brown. It was.
Further, the transmittance at 780 nm of the first layer formed on the quartz substrate was measured by an ultraviolet-visible self-recording spectrophotometer (manufactured by Hitachi), and found to be 95%.

(Analysis and evaluation of the second layer)
The second layer was analyzed and evaluated in the same manner as the analysis and evaluation of the first layer.
The atomic ratio [O / Ga] and the hydrogen content (ratio of the number of H atoms to the total number of atoms of Ga, O, and H; atomic%) were as shown in Table 1.
In addition, in the diffraction image obtained by RHEED (reflection high-energy electron diffraction) measurement, no dots or lines were found, and it was found that the second layer was amorphous.
Further, as a result of the ultraviolet-visible absorption measurement, the band gap of the second layer was 4.4 eV.
Further, the surface of the second layer was not damaged even when rubbed with stainless steel.
The second layer formed on the quartz substrate was transparent, and the transmittance at 780 nm was 95%.

≪Evaluation≫
The following evaluation was performed on the electrophotographic photoreceptor with a protective layer prepared above.
The evaluation results are shown in Table 1.

<Residual potential>
First, exposure light (light source: semiconductor laser, wavelength 780 nm, output 5 mW) is applied to the electrophotographic photosensitive member (non-coated photosensitive member) before forming the protective layer and the electrophotographic photosensitive member with protective layer. The residual potential of the surface after irradiation was measured while being negatively charged to −700 V by a scorotron charger while rotating at 40 rpm while scanning the surface of the photoreceptor.
As a result, the residual potential of the non-coated photoconductor was −10 V, whereas the residual potential of the photoconductor with the protective layer was −70 V or less.

<Decrease in sensitivity due to protective layer formation>
First, the electrophotographic photosensitive member with a protective layer was negatively charged to −700 V by a scorotron charger according to the method described above.
Next, the negatively charged electrophotographic photosensitive member with a protective layer is exposed to light for exposure (light source: semiconductor laser, wavelength 780 nm, output 5 mW) to remove static electricity, and the potential decay rate (V · m ² / mJ) and determined as the sensitivity A (V · m ² / mJ) of the electrophotographic photosensitive member with a protective layer.

The sensitivity B (V · m ² / mJ) of the electrophotographic photosensitive member (non-coated photosensitive member) before forming the protective layer was measured in the same manner as the measurement of the sensitivity of the electrophotographic photosensitive member with the protective layer.
The reduction rate of sensitivity due to the formation of the protective layer was determined by the following formula 1.

Decrease rate of sensitivity due to protective layer formation (%) = ((sensitivity B−sensitivity A) / sensitivity B) × 100
... Formula 1

Next, the wavelength of light for exposure was changed from 100 nm to 800 nm at 100 nm intervals, and the rate of decrease in sensitivity (%) due to protective layer formation was determined for each wavelength.
From the sensitivity reduction rate (%) at each wavelength obtained as described above, the sensitivity reduction due to protective layer formation was evaluated according to the following evaluation criteria.

-Evaluation criteria-
A: The rate of decrease in sensitivity due to the formation of the protective layer was less than 10% over the entire wavelength region, and the decrease in sensitivity due to the formation of the protective layer was suppressed.
B: Although the rate of decrease in sensitivity due to the formation of the protective layer is 10% or more and less than 30% over the entire wavelength region, the decrease in sensitivity due to the formation of the protective layer was within a practically acceptable range.
C: The rate of decrease in sensitivity at a wavelength of 800 nm was 30% or more and 35% or less, and the decrease in sensitivity due to the formation of the protective layer was within a practically acceptable range.
D: The rate of decrease in sensitivity at a wavelength of 800 nm exceeded 35%, and the decrease in sensitivity due to the formation of the protective layer exceeded the practically acceptable range.

<Repetitive image quality evaluation>
An electrophotographic photosensitive member with a protective layer is attached to DocuCentre Color 500 manufactured by Fuji Xerox Co., Ltd., and a continuous print test of 20,000 sheets is performed under a high temperature and high humidity environment (28 ° C., 80% RH), and the following evaluation is performed. It was.
As a reference for image quality evaluation, a non-coated photoconductor was also attached to the DocuCenter Color 500 to form a similar image.

(White line)
The white streak defect on the image was evaluated for the image after 20,000 sheets were printed. The evaluation criteria are as follows.

-Evaluation criteria-
A: No white streak-like image defect is observed.
B: Slight white streak-like image defects that are thought to be caused by scratches on the photoreceptor are slightly observed, but are practically acceptable.
C: Many white streak-like image defects considered to be caused by scratches on the photoreceptor were observed, which exceeded the practically acceptable range.

(Image density)
After printing 1000 sheets, 100 solid images with 100% area coverage were printed continuously, and the image density of the obtained images was evaluated according to the following evaluation criteria.

-Evaluation criteria-
A: No decrease in image density is observed even after printing over 100 sheets.
B: In the case of more than 90 sheets and 100 sheets or less, although a slight decrease in image density is observed after printing, it is within a practically acceptable range.
C: In the case of more than 70 sheets and 90 sheets or less, although a slight decrease in image density is observed after printing, it is within a practically acceptable range.
D: At 70 sheets or less, the image density was reduced at first glance, which exceeded the practically acceptable range.

(Image blur)
For image blur, after printing 20,000 sheets, only a part of the surface of the photoreceptor was wiped with water in order to remove discharge products that are water-soluble.
After that, a halftone image (image density 30%) is printed, and the presence or absence of a density difference corresponding to a portion where the surface of the photoreceptor is wiped with water is visually confirmed in the halftone image. Evaluation was made according to the following evaluation criteria.

-Evaluation criteria-
A: No difference in density is observed.
B: Although there is a slight difference in density, it is within a practically acceptable range.
C: A difference in density could be confirmed at first glance, which exceeded the practically acceptable range.

(Scratches)
The surface of the photoreceptor after the 20,000-sheet print test was visually observed to check for the presence or absence of scratches on the surface.
The evaluation criteria are as follows.

-Evaluation criteria-
A: No scratches on the surface are observed.
B: Although scratches on the surface are slightly seen, it is within a practically acceptable range.
C: Scratches on the surface could be confirmed at first glance, which exceeded the practically acceptable range.

<Increase in residual potential (RP) during repeated use>
First, the residual potential at a wavelength of 780 nm was measured for the electrophotographic photosensitive member with a protective layer before the print test for 20,000 sheets in the image quality evaluation.
Next, after 20,000 print tests in the above image quality evaluation, the residual potential at a wavelength of 780 nm was measured for the electrophotographic photosensitive member with a protective layer.
Based on these results, an increase in residual potential (increase rate (%)) during repeated use was evaluated according to the following evaluation criteria.
In Table 1 below, the residual potential is expressed as “RP”.

-Evaluation criteria-
A: The increase in residual potential by a print test of 20,000 sheets was less than 10%, and the decrease in residual potential during repeated use was suppressed.
B: The increase in the residual potential due to the print test of 20,000 sheets was 10% or more and less than 30%, and the increase in the residual potential during repeated use was within a practically acceptable range.
C: The increase in the residual potential due to the print test of 20,000 sheets was 30% or more, and the increase in the residual potential during repeated use exceeded the practically acceptable range.

[Electrophotographic photoreceptor 2]
During the production of the electrophotographic photosensitive member 1, an electrophotographic photosensitive member with a protective layer is formed in the same manner as the electrophotographic photosensitive member 1 except that the flow rate of He-diluted 20% oxygen gas is changed to 10 sccm in the formation of the second layer. The same analysis and evaluation as the electrophotographic photoreceptor 1 were performed.
The results of analysis and evaluation are shown in Table 1 below.
In addition, in the diffraction image obtained by RHEED (reflection high-energy electron diffraction) measurement, no dots or lines were found, and it was found that the second layer was amorphous.
Further, the surface of the second layer was not damaged even when rubbed with stainless steel.
The second layer formed on the quartz substrate was pale yellow and the transmittance at 780 nm was 85%.

[Electrophotographic photoreceptor 3]
During the production of the electrophotographic photosensitive member 1, in the formation of the second layer, He diluted 20% oxygen gas (20 sccm), He gas (100 sccm), and H ₂ gas (500 sccm) were mixed with He diluted 20% oxygen gas (7 sccm). ) And He gas (200 sccm), and further, the electrophotographic photosensitive member with a protective layer was produced in the same manner as the electrophotographic photosensitive member 1 except that the film formation time was changed to 180 minutes. The same analysis and evaluation were performed.
The results of analysis and evaluation are shown in Table 1 below.
In addition, in the diffraction image obtained by RHEED (reflection high-energy electron diffraction) measurement, no dots or lines were found, and it was found that the second layer was amorphous.
Further, the surface of the second layer was not damaged even when rubbed with stainless steel.
The second layer formed on the quartz substrate was lightly brown and the transmittance at 780 nm was 70%.

[Electrophotographic photoreceptor 4]
During the production of the electrophotographic photosensitive member 3, an electrophotographic photosensitive member with a protective layer was produced in the same manner as the electrophotographic photosensitive member 3, except that the film formation time was changed to 60 minutes in the formation of the second layer. Analysis and evaluation similar to those of the photographic photoreceptor 3 were performed.
The results of analysis and evaluation are shown in Table 1 below.
In addition, in the diffraction image obtained by RHEED (reflection high-energy electron diffraction) measurement, no dots or lines were found, and it was found that the second layer was amorphous.
Further, the surface of the second layer was not damaged even when rubbed with stainless steel.
The second layer formed on the quartz substrate was light yellow and the transmittance at 780 nm was 80%.

[Electrophotographic photoreceptor 5]
During the formation of the electrophotographic photoreceptor 1, in the formation of the second layer, the flow rate of He-diluted 20% oxygen gas is 40 sccm, trimethylgallium gas (3 sccm) is trimethylgallium gas (2.4 sccm), and diethylzinc (0. 6 sccm), an electrophotographic photosensitive member with a protective layer was produced in the same manner as in the electrophotographic photosensitive member 1 except that each was changed, and the same analysis and evaluation as the electrophotographic photosensitive member 1 were performed.
The results of analysis and evaluation are shown in Table 1 below.
In addition, in the diffraction image obtained by RHEED (reflection high-energy electron diffraction) measurement, no dots or lines were found, and it was found that the second layer was amorphous.
Further, the surface of the second layer was not damaged even when rubbed with stainless steel.
The second layer formed on the quartz substrate was transparent, and the transmittance at 780 nm was 95%.

[Electrophotographic photoreceptor 6]
During the production of the electrophotographic photosensitive member 5, in the formation of the second layer, trimethyl gallium gas (2.4 sccm) and diethyl zinc (0.6 sccm) are replaced with trimethyl gallium gas (2.1 sccm) and diethyl zinc (0.9 sccm). The electrophotographic photosensitive member with a protective layer was prepared in the same manner as in the electrophotographic photosensitive member 5 except that it was changed to), and the same analysis and evaluation as the electrophotographic photosensitive member 5 were performed.
The results of analysis and evaluation are shown in Table 1 below.
In addition, in the diffraction image obtained by RHEED (reflection high-energy electron diffraction) measurement, no dots or lines were found, and it was found that the second layer was amorphous.
Further, the surface of the second layer was not damaged even when rubbed with stainless steel.
The second layer formed on the quartz substrate was transparent, and the transmittance at 780 nm was 95%.

[Electrophotographic photoreceptor 7]
In the production of the electrophotographic photoreceptor 5, a protective layer is provided in the same manner as the electrophotographic photoreceptor 5 except that the non-coated photoreceptor (2) produced as follows is used instead of the non-coated photoreceptor (1). An electrophotographic photoreceptor was prepared, and analysis and evaluation similar to those of the electrophotographic photoreceptor 5 were performed.
The results of analysis and evaluation are shown in Table 1 below.
The obtained electrophotographic photoreceptor with a protective layer had good adhesiveness because the protective layer was not peeled off even by the pressure-sensitive adhesive tape. The surface property was smoother than the surface of the non-coated photoreceptor (2) before the protective layer was formed, and the slip was good.

-Production of non-coated photoreceptor (2)-
A 3 μm n-type Si ₃ N ₁ charge injection blocking layer, a 20 μm i-type amorphous silicon photoconductive layer, a 0.5 μm p-type Si ₂ C ₁ charge injection blocking surface layer on an Al substrate; Are formed in this order by plasma CVD to produce a non-coated photoreceptor (2) which is a negatively charged amorphous silicon photoreceptor.

[Electrophotographic photoreceptor 8]
During the production of the electrophotographic photosensitive member 1, an electrophotographic photosensitive member with a protective layer is formed in the same manner as the electrophotographic photosensitive member 1 except that an intermediate layer is formed after the formation of the second layer and before the formation of the first layer. The same analysis and evaluation as the electrophotographic photosensitive member 1 were performed.
The results of analysis and evaluation are shown in Table 1 below.
Here, the film formation conditions for the intermediate layer are the same as those for the second layer except that the flow rate of He diluted 20% oxygen gas is changed to 8 sccm and the film formation time is changed to a layer thickness of 0.1 μm. It is.

[Electrophotographic photoreceptor 9]
During the production of the electrophotographic photoreceptor 1, the electrophotographic photoreceptor 1 and the electrophotographic photoreceptor 1 except that the third layer was formed on the surface of the non-coated photoreceptor (1) before the formation of the second layer on the surface of the non-coated photoreceptor (1). Similarly, an electrophotographic photosensitive member with a protective layer was prepared, and analysis and evaluation similar to those of the electrophotographic photosensitive member 1 were performed.
The results of analysis and evaluation are shown in Table 1 below.
The film formation conditions for the intermediate layer were the same as those for the second layer except that the flow rate of He diluted 20% oxygen gas was changed to 8 sccm and the film formation time was changed to a layer thickness of 0.05 μm. is there.

[Comparative electrophotographic photoreceptor 1]
During the production of the electrophotographic photoreceptor 1, the second layer was formed in the same manner as the electrophotographic photoreceptor 1 except that the flow rate of He-diluted 20% oxygen gas was changed to 1 sccm and the film formation time was changed to 240 minutes. Then, an electrophotographic photosensitive member with a protective layer was prepared, and the same analysis and evaluation as the electrophotographic photosensitive member 1 were performed.
The results of analysis and evaluation are shown in Table 1 below.
The second layer (analytical sample film) formed on the quartz substrate was colored brown and the transmittance at 780 nm was 40%.

[Comparative electrophotographic photoreceptor 2]
During the production of the electrophotographic photoreceptor 1, the flow rate of He diluted 20% oxygen gas is changed to 2 sccm in the formation of the first layer, and the flow rate of He diluted 20% oxygen gas is changed in the formation of the second layer. An electrophotographic photosensitive member with a protective layer was prepared in the same manner as the electrophotographic photosensitive member 1 except that the film formation time was changed to 1 sccm and 180 minutes, and the same analysis and evaluation as the electrophotographic photosensitive member 1 were performed. .
The results of analysis and evaluation are shown in Table 1 below.
The second layer (analytical sample film) formed on the quartz substrate was colored brown and the transmittance at 780 nm was 50%.

As shown in Table 1, the structure of the protective layer is an electron having a first region including the outermost surface and a second region having a larger atomic ratio [oxygen / gallium] than the first region. In Photographic Photoreceptor 1 to Electrophotographic Photoreceptor 9, a decrease in sensitivity due to the formation of the protective layer was suppressed, and a decrease in image density accompanying a decrease in sensitivity was also suppressed.
Further, in the electrophotographic photosensitive member 1 to the electrophotographic photosensitive member 9, the residual potential was also reduced.
On the other hand, in the comparative electrophotographic photosensitive member 1 and the comparative electrophotographic photosensitive member 2, the sensitivity was remarkably lowered and the image density was low.
Further, it was found that the specific electrophotographic photoreceptor 1 and the comparative electrophotographic photoreceptor 2 have a slow growth rate (film formation rate) and low productivity.

[Example 1 to Example 9]
According to Table 2, the electrophotographic photoreceptor produced as described above is incorporated into Fuji Xerox's DocuCenter Color 500 remodeling machine (the charge injection suppression material supply device having the following configuration is incorporated in the cleaning device downstream of the photoreceptor rotation direction from the cleaning blade. The following evaluation was performed. The results are shown in Table 2.

(Configuration of charge injection suppression material supply device)
The charge injection suppressing material supply device mechanically transfers a rotating brush disposed in contact with the electrophotographic photosensitive member, a solid charge injection suppressing material disposed in contact with the rotating brush, and toner attached to the rotating brush. Consists of flicker (plate-like member) that knocks down.
-Details of configuration-
Charge injection suppression material: Zinc stearate (Nisshin Chemical Co., Ltd., volume resistivity 17 LogΩcm)
・ Rotating brush: Conductive nylon (trade name Beltron Co., Ltd., Ashiya)), fiber thickness is 3 denier), fiber density is 50 Kf / inch ² , brush penetration into electrophotographic photosensitive member is 0.5 mm ), The outer diameter is Φ12mm), the shaft diameter is Φ6mm)
Rotating brush drive conditions: shaft is grounded, rotating direction is the same as the electrophotographic photosensitive member, rotating speed is 1.2 times the rotating speed of the electrophotographic photosensitive member flicker (plate member): 0.5 mm thick Polypropylene resin plate (biting into rotating brush 0.5mm)
Supply amount of charge injection suppressing material: A charge injection suppressing material having a total weight of 40 g with a weight placed thereon was placed on the rotating brush by its own weight, and the amount was 6 mg per 1000 rotations of the electrophotographic photosensitive member.

(Evaluation)
-Evaluation of photoreceptor surface potential reduction-
In the following manner, the surface potential of the electrophotographic photoreceptor was measured before and after development by the developing device, and the decrease in the surface potential of the electrophotographic photoreceptor was measured according to the following evaluation criteria. When the surface electrometer probe is placed so as to face the upstream and downstream electrophotographic photosensitive member surfaces across the development device, and a solid white image is taken, the potential from the upstream potential to the downstream potential is reduced. We evaluated how many volts it drops. Even when the measurement is performed with the developing device removed, there is a 50 V potential drop. This amount is thought to be due to dark decay.
-Evaluation criteria-
AAA: 55 V or less, and there is no problem at all with a potential drop corresponding to AAA for image quality evaluation described later.
AA: More than 55V and 60V or less. There is no problem with a potential drop corresponding to AA for image quality evaluation described later.
A: More than 60V and 65V or less. There is no problem with a potential drop corresponding to A in image quality evaluation described later.
B: More than 65V and 75V or less. There is a problem with a potential drop corresponding to B in image quality evaluation described later.
C: Greater than 75V. There is a problem with a potential drop corresponding to C in image quality evaluation described later.

-Image evaluation-
After outputting 50,000 halftone images (image density 30%), the graininess of the images was evaluated according to the following evaluation criteria.
-Evaluation criteria-
AAA: There is no rough feeling and there is no problem in actual use.
AA: Although there is a slight feeling of roughness in part, there is no problem in actual use.
A: Although there are more areas with a slightly rough feeling than AA, there is no problem in actual use.
B: There is a rough feeling and there is a problem in actual use.
C: Clearly rough feeling and a problem in practical use.

[Comparative Examples 1 to 11]
According to Table 2, the produced electrophotographic photosensitive member was mounted on DocuCentre Color 500 (without a charge injection suppressing material supply device) manufactured by Fuji Xerox Co., Ltd., and the same evaluation as in Example 1 was performed. The results are shown in Table 2.

  From the above results, it can be seen that in this example, compared with the comparative example, a decrease in the surface potential of the photoconductor is suppressed, uneven surface potential is suppressed, and an image with good image graininess can be obtained.

DESCRIPTION OF SYMBOLS 1 Substrate, 2 Photosensitive layer, 2A Charge generation layer, 2B Charge transport layer, 3 Protective layer, 4 Undercoat layer, 210 Deposition chamber, 211 Exhaust port, 212 Substrate rotating part, 213 Substrate support member, 214 Base material 215, 220 Gas introduction pipe, 216 Shower nozzle, 217 Plasma diffusion section, 218 High frequency power supply section, 219 Plate electrode, 221 High frequency discharge pipe section, 222 High frequency coil, 223 Quartz tube, 3A First region, 3B Second Region, 3C third region, 3D first layer, 3E second layer, 3F intermediate layer,
DESCRIPTION OF SYMBOLS 10 Electrophotographic photosensitive member, 10A Electrophotographic photosensitive member, 10B Electrophotographic photosensitive member, 20 Charging device, 30 Exposure device, 40 Developing device, 41 Developing container, 41A Developing container main body, 41B Developing container cover, 41C Wall, 42 Developing roll 42A developing roll chamber, 43 agitating member, 43A agitating chamber, 44 agitating member, 44A agitating chamber, 45 layer thickness regulating member, 46 replenishing conveyance path, 47 replenishing developer storage container, 50 intermediate transfer member, 50A supporting roller, 50B support roller, 50C back roller, 50D drive roller, 51 primary transfer device, 52 secondary transfer device, 53 recording paper supply device, 53A transport roller, 53B guide slope, 54 intermediate transfer member cleaning device, 70 cleaning device, 71 housing Body, 72 cleaning blade, 80 fixing device, 81 fixing roller, 82 transport conveyor 101 image forming apparatus, 101A process cartridge,

Claims (2)

A base, a photosensitive layer, oxygen and gallium, a first region existing on the outer peripheral surface side, and a side closer to the base than the first region, compared to the first region A protective layer having a second region having a large atomic ratio [oxygen / gallium], and an electrophotographic photosensitive member in this order;
Charging means for charging the surface of the electrophotographic photosensitive member; and latent image forming means for forming an electrostatic latent image by exposing the surface of the electrophotographic photosensitive member charged by the charging means;
Developing means for developing the electrostatic latent image formed on the electrophotographic photosensitive member with a developer containing toner to form a toner image;
Transfer means for transferring the toner image formed on the electrophotographic photosensitive member to a recording medium;
A supply means for supplying a material for suppressing charge injection to the surface of the electrophotographic photosensitive member on the surface of the electrophotographic photosensitive member;
An image forming apparatus. A base, a photosensitive layer, oxygen and gallium, a first region existing on the outer peripheral surface side, and a side closer to the base than the first region, compared to the first region A protective layer having a second region having a large atomic ratio [oxygen / gallium], and an electrophotographic photosensitive member in this order;
A supply means for supplying a material for suppressing charge injection to the surface of the electrophotographic photosensitive member on the surface of the electrophotographic photosensitive member;
Process cartridge with