JP2009237114A - Image forming apparatus and processing method of photoreceptor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus wherein electrical characteristics are uniform within a photoreceptor surface regardless of time lapse and uniformity of image quality is obtained from the initial stage. <P>SOLUTION: The image forming apparatus includes the photoreceptor provided with an organic photosensitive layer and a surface layer containing a group 13 element and oxygen on a conductive substrate, a charging means, an exposure means, a developing means, a transfer means, a cleaning means, an elastic member, and a control means for rotating the photoreceptor when not forming images and pressing the elastic member to the rotated photoreceptor surface. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image forming apparatus and a photoconductor processing method.

In recent years, copiers and printers using an electrophotographic system have been widely used.
In an image forming apparatus using such an electrophotographic system, various proposals have been made to achieve both the prevention of image flow in a high humidity environment and the extension of the life of the photoreceptor by reducing the amount of wear. However, when the amount of wear on the photoconductor is extremely small, there is no definitive improvement measure other than the addition of a heater for dehumidification in order to prevent image flow due to discharge products, and a new load has been generated. .

Under such circumstances, an organic photosensitive film in which an inorganic surface layer made of oxygen gallium is formed by a plasma CVD method is used to prevent both image flow without using a heater and to reduce the wear amount of the photoconductor. An electrophotographic image forming apparatus such as a copying machine or a printer using the same has been proposed (for example, see Patent Document 1).
Further, as another means, there is a proposal (for example, refer to Patent Document 2) that polishes the surface of the photosensitive member with an elastic roller to prevent image flow, and charging unevenness due to improvement of the surface layer of the conductive elastic roller that forms a contact charger. Proposals have been made (see, for example, Patent Documents 3 to 5).
JP 2006-267507 A Japanese Patent Laid-Open No. 10-312139 JP-A-5-257363 JP-A-8-137194 JP 2006-145636 A

As described above, various proposals have been made, but changes in in-plane uniformity with the lapse of time of the electrical characteristics of the photoconductor are not taken into consideration, and it is long until the in-plane image quality uniformity is obtained. The current situation is that it takes time.
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an image forming apparatus in which the electrical characteristics are uniform within the surface of the photosensitive member regardless of the passage of time, and uniformity of image quality can be obtained from the beginning.
It is another object of the present invention to provide a method for processing a photoconductor in which the electrical characteristics are uniform in the surface of the photoconductor regardless of the passage of time.

The above object can be achieved by the following embodiments of the present invention. That is,
The invention according to claim 1 is a photoreceptor having an organic photosensitive layer and a surface layer containing a Group 13 element and oxygen on a conductive substrate, a charging unit, an exposing unit, a developing unit, a transferring unit, An image forming apparatus comprising: a cleaning unit; an elastic member; and a control unit that rotates the photosensitive member and presses the elastic member against a surface of the rotating photosensitive member.

According to a second aspect of the present invention, the elastic member is included in any one of the charging unit, the developing unit, the transfer unit, and the cleaning unit, and the control unit does not perform image formation. The image forming apparatus according to claim 1, wherein the photosensitive member is rotated, and the elastic member is pressed against a surface of the rotating photosensitive member.
According to a third aspect of the present invention, the charging unit is a non-contact type, and the elastic member is a roll made of a rubber-like elastic body, and the roll is pressed against the photoconductor by the control unit, The image forming apparatus according to claim 1, wherein the image forming apparatus rotates in contact with the photosensitive member.

The invention according to claim 4 is the image forming apparatus according to any one of claims 1 to 3, wherein the group 13 element in the surface layer is gallium.
The invention according to claim 5 is the image forming apparatus according to any one of claims 1 to 4, wherein the thickness of the surface layer is 0.05 μm or more and 1.0 μm or less.
The invention according to claim 6 is characterized in that the elastic member is pressed by a force of 1 g / cm or more and 10 g / cm or less per unit length in the rotation axis direction of the photoconductor. The image forming apparatus according to any one of the above.

  According to a seventh aspect of the present invention, there is provided an elastic member for a photosensitive member having an organic photosensitive layer and a surface layer containing a Group 13 element and oxygen on a conductive substrate. The photosensitive member processing method is characterized by pressing with a force of 1 g / cm to 10 g / cm per unit length.

According to the present invention, compared to a case where the present configuration is not provided, there is provided an image forming apparatus in which the electrical characteristics are uniform in the surface of the photosensitive member regardless of the passage of time, and uniformity of image quality can be obtained from the beginning. Can do.
In addition, according to the present invention, it is possible to provide a method for processing a photoreceptor in which electrical characteristics are uniform in the surface of the photoreceptor regardless of the passage of time.

  Hereinafter, the image forming apparatus of the present invention and the processing method of the photoreceptor will be described in detail.

<Image forming apparatus>
The image forming apparatus of the present invention includes a photosensitive member having an organic photosensitive layer and a surface layer containing a Group 13 element and oxygen on a conductive substrate, a charging unit, an exposing unit, a developing unit, a transferring unit, An image forming apparatus comprising: a cleaning unit; an elastic member; and a control unit that rotates the photosensitive member and presses the elastic member against a surface of the rotating photosensitive member.
In particular, in the present invention, the elastic member may be included in any one of a charging unit, a developing unit, a transfer unit, and a cleaning unit. In other words, any of the means that can come into contact with the photosensitive member, such as the charging means, the exposure means, the developing means, and the cleaning means, is an elastic member, so that the image of the present invention is not provided separately. A configuration of the forming apparatus can be obtained. However, in this case, it is necessary to rotate the photosensitive member by the control means when image formation is not performed, and to press the elastic member against the surface of the rotating photosensitive member.

The image forming apparatus of this embodiment will be described with reference to FIGS.
Here, FIGS. 1 to 5 are schematic cross-sectional views showing an example of the configuration of the first to fifth image forming apparatuses of the present embodiment.
FIG. 1 shows an image forming apparatus 1a in which the charging means is constituted by an elastic member (elastic roll) 20a, and the elastic roll 20a is controlled by the control means 80.
FIG. 2 shows an image forming apparatus 1 b in which the developing unit includes an elastic member (elastic roll) 42 and the elastic roll 42 is controlled by the control unit 80.
FIG. 3 shows an image forming apparatus 1c in which the transfer unit is constituted by an elastic member (elastic roll) 50a, and the elastic roll 50a is controlled by the control unit 80.
FIG. 4 shows an image forming apparatus 1 d in which the cleaning unit includes an elastic member (elastic roll) 62 and the elastic roll 62 is controlled by the control unit 80.
FIG. 5 shows a configuration in which an elastic member (elastic roll) 70 is provided downstream of the cleaning unit and upstream of the charging unit with respect to the rotation direction of the photosensitive member. An image forming apparatus 1e in the case of being controlled is shown.

As described above, the image forming apparatus according to this embodiment has a configuration in which the elastic member (elastic roll) is pressed against the photosensitive member by the control unit 80.
Here, the control means 80 controls the pressing of the elastic member against the surface of the rotating photoreceptor. When the elastic member is included in any one of the charging unit, the developing unit, the transfer unit, and the cleaning unit, the photosensitive member is rotated by rotating the photosensitive member when image formation is not performed. It is necessary to press the elastic member against the body surface. Here, “when image formation is not performed” specifically refers to measurement of the warm-up waiting time after power-on of the image forming apparatus, the return time from the standby state, and the electrical characteristics of the photoconductor for stabilizing the image quality. This means that the image forming apparatus is in a state other than being sequentially executed in order to output image information, which is the original purpose, such as time.

When the elastic member is pressed against the surface of the photosensitive member, the pressing pressure is more practical than the surface pressure because there is a large pressure distribution in the nip. The shape of the photoconductor is defined, and it is preferably 1 g / cm or more and 10 g / cm or less in terms of a linear pressure that becomes a load per unit length in the rotation axis direction.
Further, the pressing time is indicated by the accumulated time required for the surface of the photosensitive member to pass through the nip formed by the photosensitive member and the elastic member, and is preferably 100 seconds or more.
Further, when the elastic member is pressed against the surface of the photoreceptor, it is preferable to repeatedly press (press) and release, and it is preferable to repeat 100 times or more.

Furthermore, the shape of the elastic member used in this embodiment is not limited as long as the above-described pressing is possible, and may be an elastic roll made of a rubber-like elastic body as shown in FIGS. And what is necessary is just what pressed the edge part of the elastic pad and the plate-shaped elastic member.
Moreover, as an elastic material (rubber-like elastic body) constituting the elastic member used in the present embodiment, urethane rubber, foamed urethane rubber, epichlorohydrin rubber, silicone rubber, polyimide-modified silicone rubber, fluorine rubber, butadiene rubber, isoprene rubber, Nitrile rubber, natural rubber, EPDM (ethylene-propylene-diene copolymer rubber) and the like are used. Among them, a rubber whose hardness is A50 or more and A80 or less in the type A durometer hardness specified in JIS K 6253 is preferable.

The photosensitive layer in the image forming apparatus of this embodiment is characterized by having a surface layer containing a Group 13 element and oxygen on the organic photosensitive layer.
In general, such a surface layer is often formed by a plasma CVD method, and stress is generated due to a difference in thermal expansion coefficient between the surface layer and the organic photosensitive layer due to a temperature rise during the formation of the surface layer. As a result, the sensitivity of the organic photosensitive layer was lowered, and this stress relaxation occurred nonuniformly in the plane with time.
In this embodiment, by rotating the organic photoconductor having the surface layer as described above and pressing the elastic member against the rotating organic photoconductor, a pressing frictional force is applied to the surface of the photoconductor, and the organic photoconductor The stress considered to be generated between the layer and the surface layer can be alleviated uniformly, and as a result, the electrical characteristics of the photoreceptor can be made uniform in a short time. Therefore, in the image forming apparatus of the present invention, it is possible to obtain image quality uniformity from the initial printing stage.
Hereafter, each member which comprises the image forming apparatus shown by FIGS. 1-5 is demonstrated.

[Photoreceptor]
A photoconductor (photoconductor 10 in FIGS. 1 to 5) in the image forming apparatus of the present embodiment includes an organic photosensitive layer and a surface layer containing a Group 13 element and oxygen on a conductive substrate. Have.
The photoconductor having such a structure includes a Group 13 element oxide having excellent hardness and transparency as a surface layer, and therefore has excellent surface wear resistance, suppresses the generation of scratches, and has good sensitivity. Is easy to get. In addition, the photoreceptor having this surface layer is not easily oxidized in an image forming apparatus in an oxidizing atmosphere such as ozone or nitrogen oxide generated by a charger. Deterioration can be prevented. Moreover, since it is excellent in mechanical durability and oxidation resistance, it is easy to maintain these characteristics at a high level over a long period of time.

  The photoreceptor in the present embodiment is not particularly limited as long as an organic photosensitive layer and a surface layer are laminated in this order on a conductive substrate, and a lower layer which will be described later if necessary between these three layers. An intermediate layer such as a drawing layer may be provided. Further, the organic photosensitive layer may be two or more layers, and may be a function separation type.

Hereinafter, a specific example of the layer structure of the photoreceptor in the present embodiment will be described in more detail with reference to FIG. Here, FIG. 6 is a schematic cross-sectional view showing an example of the layer structure of the photoreceptor suitable for the present embodiment.
A photoconductor 210 shown in FIG. 6 has a configuration in which an undercoat layer 213, an organic photosensitive layer 215 including a charge generation layer 215 a and a charge transport layer 215 b, and a surface layer 217 are provided in this order on a conductive substrate 211. .

(Surface layer)
First, the surface layer 217 will be described.
This surface layer is characterized by comprising at least a Group 13 element and oxygen, and may be composed of only these two elements, but does not impair the effects of the present invention. May contain elements such as nitrogen, hydrogen, and carbon. By including such other elements, various physical properties of the surface layer can be easily and flexibly controlled, and the effects of the present invention can be further enhanced.

  The composition in the surface layer in the present embodiment may be uniform, but contains a Group 13 element and oxygen, and the mass ratio of oxygen to the Group 13 element is 0.9 to 1.4. Is preferred. If the mass ratio of oxygen to the Group 13 element is 0.9 to 1.4, it may be inclined in the thickness direction. Further, the surface layer in the present embodiment contains a group 13 element and oxygen, and if the mass ratio of oxygen to the group 13 element is 0.9 to 1.4, layers having different compositions are used. You may have the multilayered structure formed by laminating | stacking.

In the surface layer in the present embodiment, the oxygen concentration distribution in the thickness direction may be uniform or non-uniform, but decreases toward the organic photosensitive layer side (that is, increases toward the surface side of the surface layer). Preferably it is. In particular, it is preferable that the surface layer is composed of oxygen and gallium in the vicinity of the surface layer, and the organic photosensitive layer side is composed of elements other than oxygen and gallium (that is, does not contain oxygen).
By having such an oxygen concentration distribution, it is possible to achieve a higher level of both mechanical durability, oxidation resistance, image defects and sensitivity due to adhesion of discharge products, and to improve these characteristics. It is easy to maintain for a long period of time, and in particular, when the element other than oxygen is nitrogen, such an effect is further exhibited. In addition, the distribution profile of the oxygen concentration in the surface layer thickness direction is not particularly limited, and may be, for example, linear, curved, or stepped.

As the group 13 element contained in the surface layer, specifically, at least one element selected from B, Al, Ga, and In can be used. The content of these atoms in the surface layer needs to be selected so as not to absorb as much light as possible used for exposure of the surface of the photoreceptor, but in general, it is preferably within the following range.
That is, the content of these atoms in the surface layer when using B, Al and Ga atoms is preferably in the range of 0.1 atomic% to 50 atomic%, and in the range of 5 atomic% to 40 atomic%. More preferably, it is within. When the content of B, Al, or Ga atoms is less than 0.1 atomic%, the formation of the surface layer itself may be difficult. On the other hand, if the content exceeds 50 atomic%, the transparency of the surface layer is lowered, the amount of light incident on the photosensitive layer is reduced, and the sensitivity of the photoreceptor may be lowered.
The content in the case of using In atoms as the group 13 element is preferably 0.1 atomic% to 50 atomic%, and more preferably 5 atomic% to 40 atomic%. If they are out of these ranges, the same problem as described above may occur.

Moreover, as for content of oxygen in a surface layer, the content mass ratio with respect to a Group 13 element has preferable 0.9-1.4.
More specifically, the oxygen content in the surface layer is preferably more than 15 atomic%, preferably 20 atomic% to 60 atomic%, and more preferably 25 atomic% to 50 atomic%. When the oxygen content is less than 15 atomic%, the oxidation resistance of the surface of the photoreceptor becomes insufficient, and when used in an image forming apparatus, the characteristics of the photoreceptor deteriorate or sufficient mechanical properties are obtained. May not be secured.

  When nitrogen is contained in the surface layer in this embodiment, the content is preferably 30 atomic percent or less, and more preferably 15 atomic percent or less. When the nitrogen content exceeds 30 atomic%, the water resistance of the surface layer becomes insufficient, so that it may lack practicality. Further, the concentration distribution of nitrogen in the thickness direction of the surface layer may be uniform or non-uniform, but it is preferable that it is not substantially contained in the outermost surface.

  When carbon is contained in the surface layer in the present embodiment, the content is preferably 2 atom% or more and 15 atom% or less, more preferably 2 atom% or more and 10 atom% or less. By setting the carbon content in the surface layer to 2 atom% or more and 15 atom% or less, an effect of obtaining a highly water-repellent low energy surface can be obtained.

When hydrogen is contained in the surface layer in the present embodiment, the content is preferably in the range of 0.1 atomic% to 30 atomic%, and more preferably in the range of 0.5 atomic% to 20 atomic%. When the hydrogen content is less than 0.1 atomic%, structural disturbances remain embedded in the layer, which may cause electrical instability and insufficient mechanical properties. . In addition, when it exceeds 30 atomic%, the probability that hydrogen is bonded to two or more atoms in gallium is increased, and the three-dimensional structure cannot be maintained, and the hardness and chemical stability (particularly water resistance) are insufficient. It may become.
The hydrogen content in the surface layer is preferably in the range of 0.1 atomic% to 50 atomic% with respect to the entire two main elements (Group 13 element and oxygen) constituting the surface layer. More preferably, it is in the range of not less than 40% and not more than 40%.

About content of each element in the whole surface layer in this embodiment, Rutherford back scattering method (RBS), a hydrogen forward scattering method (HFS), etc. can be used.
Hereinafter, these measurement methods will be described.

  In the present embodiment, the content of elements such as Group 13 elements, oxygen, carbon, and nitrogen in the surface layer is a value obtained by Rutherford Backscattering (RBS) including distribution in the film thickness direction. I mean.

  As the RBS, an accelerator: NEC 3SDH Pelletron, an end station: CE & A RBS-400 was used, and 3S-R10 was used as the system. The analysis used the CE & A HYPRA program.

The RBS measurement conditions are as follows.
He ++ ion beam energy is 2.275 eV
Detection angle 160 °
Grazing angle 109 ° with respect to the incident beam

  In the RBS measurement, a He ++ ion beam is incident substantially perpendicular to the sample, 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. Further, the spectrum may be measured at two detection angles in order to improve the accuracy of obtaining the composition ratio and the film thickness. In addition, the accuracy can be improved by performing cross check by measuring at two detection angles having different depth direction resolution and backscattering dynamics.

  The number of He atoms back-scattered by the target atom is determined only 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 by calculation from the measured composition, and this is used to calculate the film thickness. The density error is within 20%.

  In the present embodiment, the hydrogen content in the surface layer means a value obtained by the hydrogen forward scattering method (HFS).

As the HFS,
Accelerator: NEC 3SDH Pelletron, end station: CE & A RBS-400, 3S-R10 was used as a system. For the analysis, the CE & A HYPRA program was used.

The measurement conditions of HFS are as follows.
He ++ ion beam energy: 2.275 eV
Detection angle 160 ° Grazing Angle 30 ° for incident beam

  The measurement by HFS can pick 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 may be covered with a thin (10 μm) 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 implantation of H into Si and muscovite were used.

It is known that muscovite has a hydrogen concentration of 60 atomic%.
The H adsorbed on the outermost surface can be obtained by subtracting the amount of H adsorbed on the clean Si surface.

  The presence or absence of hydrogen in the semiconductor film can also be estimated from the intensity of the group 13-hydrogen bond or NH bond using infrared absorption spectrum measurement.

In the present embodiment, among the elements described above, the content of elements other than nitrogen, particularly the preferable ranges of the contents of both oxygen and group 13 elements, are satisfied at the outermost surface of the surface layer. preferable.
Here, the outermost surface of the surface layer means a very thin region whose depth from the surface is at least within a range of several nm (specifically, a range of about 1 to 50 nm from the surface). , Means a region corresponding to the measurement range in the depth direction when the solid surface is measured by XPS (X-ray photoelectron spectroscopy).

The content of elements such as Group 13 elements and oxygen on the outermost surface of the surface layer can be determined by XPS (X-ray photoelectron spectroscopy).
For example, it can be measured by using JPS9010MX manufactured by JEOL Ltd. as an XPS measuring apparatus, using an MgKα ray as an X-ray source, and irradiating at 10 kV, 20 mA. In this case, the photoelectron measurement is performed in steps of 1 eV, and the element content is determined by measuring the 3d5 / 2 for gallium element, 1s for O, and 1s for N, and calculating the spectrum area intensity and sensitivity factor. be able to. Note that Ar ion etching is performed at 500 V for about 10 seconds before measurement.

The surface layer in the present embodiment may be microcrystalline, polycrystalline, or amorphous, but is preferably amorphous from the viewpoint of improving the smoothness of the surface layer surface. The crystallinity / amorphous property can be determined by the presence or absence of a point or a line in a diffraction image obtained by RHEED (reflection high energy electron diffraction) measurement.
As will be described in detail later, the surface layer is formed on the organic photoreceptor using a vapor phase film formation method, so that the cross section may have a columnar structure depending on the film formation conditions and the like. However, it is preferable not to have such a columnar structure from the viewpoint of the slipperiness of the surface layer surface.

  Various dopants can be added to the surface layer in order to control the conductivity type. When the conductivity is controlled to be n-type, for example, one or more elements selected from Si, Ge, and Sn can be used. When the conductivity is controlled to be p-type, for example, Be, Mg, Ca One or more elements selected from Zn, Sr, and Sr can be used.

  The surface layer tends to contain many bonding defects, dislocation defects, crystal grain boundary defects and the like in its internal structure in any case of microcrystal, polycrystal or amorphous. For this reason, hydrogen and / or a halogen element may be contained in the surface layer in order to inactivate these defects. Hydrogen and halogen elements in the surface layer are taken into bond defects in the crystal, defects at the grain boundaries, etc., and have a function of eliminating the reactive sites and performing electrical compensation. For this reason, when light is irradiated to the photoreceptor, light is absorbed in the surface layer to generate carriers, and traps related to diffusion and movement of carriers generated in the photosensitive layer are suppressed. The charging characteristics of the body surface can be further stabilized.

The thickness of the surface layer in this embodiment is preferably in the range of 0.05 μm to 1.0 μm, more preferably in the range of 0.1 μm to 0.8 μm, and still more preferably in the range of 0.3 μm to 0.5 μm.
In addition, the thickness of the surface layer is a step method in which a height difference from a portion where the surface of the photoconductor is exposed by masking or a light interference method using a difference in refractive index with the photoconductor is read by a stylus type surface roughness meter, It can be measured by a light cutting method or the like.

Next, a method for forming the surface layer will be described.
The surface layer of the photoreceptor in the present invention can be formed using a film forming apparatus shown in FIG.
Here, FIG. 7 is a schematic diagram showing an example of a film forming apparatus used for forming the surface layer in the present embodiment.
As shown in FIG. 7, the film forming apparatus 100 includes a vacuum vessel 101 having a partition portion 101a, a rotating portion 103 that holds and rotates a laminate 220 in which an organic photosensitive layer is provided on a conductive substrate, A discharge unit 105 including a high-frequency power supply unit 105a and a discharge electrode 105b, a process gas supply unit 107 connected to a supply port 107a for supplying a process gas, and a material gas supply unit 109 connected to a supply port 109a for supplying a material gas And an exhaust device 111 connected to the exhaust port 111a.

In the film forming apparatus shown in FIG. 7, an exhaust device 111 is provided at one end of the vacuum vessel 101 through an exhaust port 111a, and an exhaust device 111 (exhaust port 111a) of the vacuum vessel 101 is provided. A supply port 107a for supplying a process gas, a supply port 109a for supplying a material gas, and a discharge unit 105 are provided on the opposite side to the other side.
The rotating unit 103 provided in the vacuum vessel 101 can rotate in the direction of the arrow while holding the laminate 220 in which the organic photosensitive layer is provided on the conductive substrate.

The discharge unit 105 includes a discharge electrode 105b having a discharge surface provided on the exhaust device 111 (exhaust port 111a) side, and a high-frequency power source unit 105a connected to a surface opposite to the discharge surface of the discharge electrode 105b. Yes.
Further, a supply port 107 a for supplying process gas is provided in the vicinity of the discharge electrode 105 b, and the supply port 107 a is connected to the process gas supply unit 107.
Further, a supply port 109a for supplying a material gas is provided at a position opposite to the supply port 107a with respect to the partition portion 101a. The supply port 109a is connected to the material gas supply unit 109. Yes.

The vacuum vessel 101 has a partition portion 101 a that has one end fixed to the inner wall of the vacuum vessel 101 and the other end facing the rotating portion 103 with a minute interval.
The partition portion 101a includes a discharge portion 105 having a discharge electrode 105b, and is used to partition a region to which a process gas is supplied from a region to which a material gas is supplied. In addition, the position of this partition part 101a can be set according to the magnitude | size of the laminated body 220 hold | maintained at the rotation part 103. FIG.

Formation of a surface layer can be implemented as follows, for example.
First, process gas is introduced from the supply port 107a, and high-frequency power having a frequency of 13.56 MHz, for example, is supplied from the high-frequency power supply unit 105a to the discharge electrode 105b. At this time, plasma is formed so as to spread radially from the discharge surface side of the discharge electrode 105b to the exhaust port 111a side. Here, the process gas introduced from the supply port 107a flows in the vacuum vessel 101 from the discharge electrode 105b side to the exhaust port 111a side.
The discharge electrode 105b may be one having an electrode surrounded by an earth shield.

  Here, a gas such as nitrogen, hydrogen, oxygen, helium, or argon is used as the process gas.

  Next, for example, by introducing trimethylgallium gas (material gas) diluted with hydrogen as a carrier gas from the supply port 109a, a non-single-crystal film containing gallium and oxygen is formed on the surface of the stacked body 220. be able to.

The formation temperature of the surface layer at the time of film formation is not particularly limited, but the surface temperature of the laminate 220 is preferably in the range of 10 ° C to 100 ° C, and preferably in the range of 20 ° C to 60 ° C.
The temperature of the surface of the laminate 220 may be controlled by heating and / or cooling means (not shown in the figure), or may be left to a natural temperature increase during discharge. When heating the laminated body 220, a heater may be installed at a location adjacent to the laminated body 220. When the stacked body 220 is cooled, a cooling gas or liquid may be circulated inside the stacked body 220.
In order to avoid an increase in the temperature of the surface of the multilayer body 220 due to discharge, it is effective to adjust a high-energy gas flow that strikes the surface of the multilayer body 220. In this case, conditions such as the gas flow rate, discharge output, and pressure are adjusted so as to achieve the required temperature.

Here, as a material gas, trimethylgallium, triethylgallium, t-butylgallium, trimethylindium, triethylindium, t-butylindium, trimethylaluminum, triethylaluminum, t-butyl as an organometallic compound containing gallium, indium, and aluminum. An organometallic compound such as aluminum or a hydride such as diborane can be used.
These liquids and solids can be vaporized and used alone or in a mixed state by bubbling with a carrier gas.
Two or more of these may be mixed.

  When forming a surface layer mainly containing a Group 13 element and oxygen like the surface layer in the present embodiment, it is preferable that active hydrogen exists in the vacuum vessel 101. The active hydrogen may be supplied from hydrogen atoms used as a carrier gas or hydrogen atoms contained in an organometallic compound.

In addition, a dopant can be added to the surface layer in order to control its conductivity type. As a dopant doping method at the time of film formation, SiH ₃ and SnH ₄ are used for n-type, and biscyclopentadienyl magnesium, dimethyl calcium, dimethyl strontium, dimethyl zinc, diethyl zinc, etc. are used for p-type. Can be used in the gas state. 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, a conductive surface layer such as n-type or p-type can be obtained by introducing a gas containing at least one dopant element into the vacuum vessel 101.

The plasma generating means of the film forming apparatus 100 shown in FIG. 7 uses the high-frequency power supply unit 105a, but is not limited to this. For example, a microwave oscillating device or an electrocyclotron resonance method is used. Alternatively, a helicon plasma type device may be used. Further, in the case of a high-frequency oscillation device, it may be inductive or capacitive.
Further, two or more kinds of these apparatuses may be used in combination. For example, a remote plasma apparatus for supplying active hydrogen from the process gas supply port 107a may be added. Alternatively, two or more devices of the same type may be used. In order to prevent the temperature of the stacked body 220 from rising due to plasma irradiation, a high-frequency oscillation device is preferable, but a device for preventing heat irradiation may be provided.

  When two or more types of different plasma generators (plasma generating means) are used, it is necessary to be able to generate discharges simultaneously at the same pressure. In addition, a pressure difference may be provided between the discharge region and the film formation region (the portion where the stacked body 220 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.

  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 (300 hPa-1200 hPa range). When discharging near atmospheric pressure, it is desirable to use He as a carrier gas.

  In forming the surface layer, other than the above-described method, a normal metal organic vapor phase epitaxy method or molecular beam epitaxy method can be used.

(Conductive substrate)
Next, the conductive substrate 211 will be described.
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 conductive substrate may be any of a drum shape, a sheet shape, and a plate shape.

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

  In particular, from the viewpoint of improving the adhesion to the organic photosensitive layer and improving the film-forming property, it is preferable to use an anodized surface of the aluminum substrate as described below as the conductive substrate.

Hereinafter, a method for producing a conductive substrate having an anodized surface will be described. First, as a conductive substrate, a pure aluminum system or an aluminum tube (for example, alloy numbers 1000, 3000, and 6000 series aluminum or aluminum alloy defined in JISH4080) is prepared. 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 an unstable surface, so that its physical property values tend to change over time after the film is formed. ing. In order to prevent the change of the physical property values, the anodized film is further sealed. 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, a method of immersing in an aqueous solution containing nickel acetate is 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 this metal salt or the like is excessively left on the anodic oxide film of the substrate, not only does it adversely affect the quality of the coating film formed on the anodic oxide film, but generally low resistance components tend to remain. When an image is formed using this substrate as a photoconductor, it causes a background stain. Here, “low resistance” indicates that the volume resistivity is a value of 10 ² Ωcm or less.

  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 the substrate is preferably cleaned by a multi-step cleaning process. At this time, a cleaning liquid that is as clean as possible (deionized) is used as the cleaning liquid in the final cleaning step. Moreover, it is more preferable to perform physical rubbing cleaning using a contact member such as a brush in any one of the multi-step cleaning steps.

  The film thickness of the anodized film on the substrate surface 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 photoreceptor used in this embodiment. As described above, an anodized conductive substrate can be obtained.

  The conductive substrate thus obtained has a high carrier blocking property in the anodized film formed on the substrate by anodization. Therefore, it is possible to prevent point defects (black spots, background stains) that occur when a photosensitive member using this substrate is mounted on an image forming apparatus and is subjected to reversal development (negative / positive development), and contact charging. It is possible to prevent a current leakage phenomenon from the contact charger that is sometimes generated. Further, by subjecting the anodized film to a sealing treatment, it is possible to prevent a change in physical property values with time after the preparation of the anodized film. Further, by washing the substrate after the sealing treatment, metal salts and the like attached to the surface of the substrate by the sealing treatment can be removed, and an image forming apparatus provided with a photoconductor produced using this conductive substrate Thus, it is possible to prevent the occurrence of background stains when an image is formed.

(Undercoat layer)
Next, the undercoat layer 213 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 can be used alone or as a mixture or polycondensate of a plurality of compounds. Among these, an organometallic compound containing zirconium or silicon is preferably 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 can be used alone or in combination of two or more, or further mixed with the above-described binder resin.

  As organic silicon 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-aminopropylmethylmethoxysilane, 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 preferably used.

  Examples of organic zirconium compounds (zirconium-containing organometallic compounds) include zirconium butoxide, zirconium zirconium acetoacetate, zirconium triethanolamine, acetylacetonate zirconium butoxide, ethyl acetoacetate zirconium butoxide, zirconium acetate, zirconium oxalate, zirconium lactate, Zirconium phosphonate, zirconium octoate, zirconium naphthenate, zirconium laurate, zirconium stearate, zirconium isostearate, methacrylate zirconium butoxide, stearate zirconium butoxide, isostearate zirconium butoxide and the like.

  Examples of organic titanium compounds (organometallic compounds containing titanium) include tetraisopropyl titanate, tetranormal butyl titanate, butyl titanate dimer, tetra (2-ethylhexyl) titanate, titanium acetylacetonate, polytitanium acetylacetonate, titanium octylene. Examples include glycolate, titanium lactate ammonium salt, titanium lactate, titanium lactate ethyl ester, titanium triethanolamate, polyhydroxy titanium stearate and the like.

  Examples of organoaluminum compounds (aluminum-containing organometallic compounds) include aluminum isopropylate, monobutoxyaluminum diisopropylate, aluminum butyrate, ethyl acetoacetate aluminum diisopropylate, and aluminum tris (ethyl acetoacetate).

  Moreover, as a solvent used for the undercoat layer forming coating solution for forming the undercoat layer, known organic solvents, for example, aromatic hydrocarbon solvents such as toluene and chlorobenzene, methanol, ethanol, n-propanol, Aliphatic alcohol solvents such as iso-propanol and n-butanol, ketone solvents such as acetone, cyclohexanone and 2-butanone, halogenated aliphatic hydrocarbon solvents such as methylene chloride, chloroform and ethylene chloride, tetrahydrofuran, dioxane and ethylene Examples thereof include cyclic or linear ether solvents such as glycol and diethyl ether, and ester solvents such as methyl acetate, ethyl acetate, and n-butyl acetate. These solvents can be used alone or in admixture of two or more. As a solvent that can be used when two or more solvents are mixed, any solvent that can dissolve the binder resin as the mixed solvent can be used.

  The undercoat layer is formed by first preparing an undercoat layer forming coating solution prepared by dispersing and mixing an undercoat layer coating agent and a solvent and applying the prepared undercoat layer coating solution to the substrate surface. As a coating method for the coating solution for forming the undercoat layer, it is possible to use usual methods such as a dip coating method, a ring coating method, a wire bar coating method, a spray coating method, a blade coating method, a knife coating method, and a curtain coating method. it can. In the case of forming the undercoat layer, it is preferable that the film thickness be in the range of 0.1 μm to 3 μm. By setting the film thickness of the undercoat layer within this film thickness range, it is possible to prevent a potential increase due to desensitization and repetition without excessively increasing the electrical barrier.

  By forming the undercoat layer on the substrate in this way, it is possible to improve the wettability when coating and forming the layer formed on the undercoat layer and to function as an electrical blocking layer. Can be fulfilled.

The surface roughness of the undercoat layer formed as described above is 1 / (4n) times the exposure laser wavelength λ used (where n is the refractive index of the layer provided on the outer peripheral side of the undercoat layer) to It is possible to adjust to have a roughness within a range of about 1 time. The surface roughness is adjusted by adding resin particles to the coating solution for forming the undercoat layer. Thereby, when a photoreceptor prepared by adjusting the surface roughness of the undercoat layer is used in an image forming apparatus, an interference fringe image by a laser light source can be further prevented.
As the resin particles, silicone resin particles, cross-linked polymethyl methacrylate resin particles, and the like can be used. In addition, the surface of the undercoat layer can be polished to adjust the surface roughness. As a polishing method, buffing, sand blasting, wet honing, grinding, or the like can be used. Note that in a photoconductor used for an image forming apparatus having a positively charged configuration, the laser incident light is absorbed around the extreme surface of the photoconductor and further scattered in the photoconductive layer, so that the surface roughness of the undercoat layer is adjusted. Is not strongly required.

  It is also preferable to add various additives to the coating solution for forming the undercoat layer in order to improve electrical characteristics, environmental stability, and image quality. Additives include quinone compounds such as chloranil, bromoanil and anthraquinone, tetracyanoquinodimethane compounds, fluorenones such as 2,4,7-trinitrofluorenone and 2,4,5,7-tetranitro-9-fluorenone Compounds, 2- (4-biphenyl) -5- (4-t-butylphenyl) -1,3,4-oxadiazole and 2,5-bis (4-naphthyl) -1,3,4-oxadi Azoles, oxadiazole compounds such as 2,5-bis (4-diethylaminophenyl) 1,3,4 oxadiazole, xanthone compounds, thiophene compounds, 3,3 ′, 5,5′-tetra-t- Electron transport materials such as diphenoquinone compounds such as butyl diphenoquinone, electron transport pigments such as polycyclic condensation systems and azo systems, zirconium chelate compounds, Hexafluorophosphate chelate compounds, aluminum chelate compounds, titanium alkoxide compounds, organic titanium compounds, there can be used a known material such as a silane coupling agent.

  Specific examples of the silane coupling agent used here include 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-β Examples include silane coupling agents such as-(aminoethyl) -γ-aminopropylmethylmethoxysilane, N, N-bis (β-hydroxyethyl) -γ-aminopropyltriethoxysilane, and γ-chloropropyltrimethoxysilane. Is not limited to these There.

  Specific examples of the zirconium chelate compound include zirconium butoxide, zirconium zirconium acetoacetate, zirconium triethanolamine, acetylacetonate zirconium butoxide, ethyl acetoacetate butoxide, zirconium acetate, zirconium oxalate, zirconium lactate, zirconium phosphonate, zirconium octoate. , Zirconium naphthenate, zirconium laurate, zirconium stearate, zirconium isostearate, methacrylate zirconium butoxide, stearate zirconium butoxide, isostearate zirconium butoxide and the like.

  Specific examples of the titanium chelate compound include tetraisopropyl titanate, tetranormal butyl titanate, butyl titanate dimer, tetra (2-ethylhexyl) titanate, titanium acetylacetonate, polytitanium acetylacetonate, titanium octylene glycolate, titanium lactate ammonium. Examples thereof include salts, titanium lactate, titanium lactate ethyl ester, titanium triethanolamate, and polyhydroxytitanium stearate.

  Specific examples of the aluminum chelate compound include aluminum isopropylate, monobutoxy aluminum diisopropylate, aluminum butyrate, ethyl acetoacetate aluminum diisopropylate, and aluminum tris (ethyl acetoacetate).

  These additives can be used alone, but can also be used as a mixture or polycondensate of a plurality of compounds.

In addition, it is preferable that the above-described undercoat layer forming coating solution contains at least one electron accepting substance. Specific examples of the electron accepting substance include succinic anhydride, maleic anhydride, dibromomaleic anhydride, phthalic anhydride, tetrabromophthalic anhydride, tetracyanoethylene, tetracyanoquinodimethane, o-dinitrobenzene, m-di Examples include nitrobenzene, chloranil, dinitroanthraquinone, trinitrofluorenone, picric acid, o-nitrobenzoic acid, p-nitrobenzoic acid, phthalic acid and the like. Of these, fluorenone-based, quinone-based, and benzene derivatives having an electron-withdrawing substituent such as Cl, CN, NO ₂ are more preferably used. As a result, the photosensitivity layer can be improved in photosensitivity and the residual potential can be reduced, and the photosensitivity deterioration when repeatedly used can be reduced. The undercoat layer includes a photoconductor containing an electron-accepting substance. It is possible to prevent density unevenness of the toner image formed by the image forming apparatus.

  Moreover, it is also preferable to use the following dispersion type undercoat layer coating agent instead of the above undercoat layer coating agent. Accordingly, accumulation of residual charges can be prevented by appropriately adjusting the resistance value of the undercoat layer, and the thickness of the undercoat layer can be increased. In particular, leakage during contact charging can be prevented.

Examples of the coating agent for the dispersion type undercoat layer include metal powders such as aluminum, copper, nickel, and silver, conductive metal oxides such as antimony oxide, indium oxide, tin oxide, and zinc oxide, carbon fiber, carbon Examples thereof include a conductive resin such as black or graphite powder dispersed in a binder resin. As the conductive metal oxide, metal oxide particles having an average primary particle size of 0.5 μm or less are preferably used. If the average primary particle size is too large, local conductive path formation is likely to occur, current leakage is likely to occur, and as a result, fogging or large current leakage from the charger may occur. The undercoat layer needs to be adjusted to an appropriate resistance value in order to improve leakage resistance. Therefore, the metal oxide particles described above preferably have a powder resistance of about 10 ² Ω · cm to 10 ¹¹ Ω · cm.

  In addition, if the resistance value of the metal oxide particles is lower than the lower limit of the above range, sufficient leak resistance cannot be obtained. Accordingly, metal oxide particles such as tin oxide, titanium oxide, and zinc oxide having a resistance value within the above range are more preferably used. Moreover, 2 or more types of metal oxide particles can be mixed and used. Furthermore, the resistance of the powder can be controlled by subjecting the metal oxide particles to a surface treatment with a coupling agent. As the coupling agent that can be used at this time, the same material as the coating liquid for forming the undercoat layer described above can be used. Moreover, these coupling agents can also be used in mixture of 2 or more types.

For the surface treatment of the metal oxide particles, any known method can be used, but a dry method or a wet method can be used.
In the case of using the dry method, first, the metal oxide particles are dried by heating to remove surface adsorbed water. By removing the surface adsorbed water, the coupling agent can be uniformly adsorbed on the surface of the metal oxide particles. Next, while stirring the metal oxide particles with a mixer having a large shearing force or the like, the coupling agent dissolved directly or in an organic solvent or water is dropped and sprayed together with dry air or nitrogen gas to uniformly treat the particles. . When adding or spraying the coupling agent, it is preferably performed at a temperature of 50 ° C. or higher. After adding or spraying the coupling agent, baking is preferably performed at 100 ° C. or higher. Due to the effect of baking, the coupling agent can be cured to cause a solid chemical reaction with the metal oxide particles. Baking can be carried out in an arbitrary range as long as the temperature and the time at which desired electrophotographic characteristics are obtained.

  When using the wet method, the surface adsorbed water of the metal oxide particles is first removed as in the dry method. As a method for removing the surface adsorbed water, in addition to the heat drying similar to the dry method, a method of removing with stirring and heating in a solvent used for the surface treatment, a method of removing by azeotropy with the solvent, and the like can be performed. Next, the metal oxide particles are dispersed in a solvent using stirring, ultrasonic waves, a sand mill, an attritor, a ball mill, etc., added with a coupling agent solution, stirred or dispersed, and then uniformly removed by removing the solvent. Is done. After removing the solvent, baking can be performed at 100 ° C. or higher. Baking can be carried out in an arbitrary range as long as the temperature and time allow the desired electrophotographic characteristics to be obtained.

It is essential that the amount of the surface treatment agent with respect to the metal oxide particles is an amount capable of obtaining desired electrophotographic characteristics. The electrophotographic characteristics are affected by the amount of the surface treatment agent attached to the metal oxide particles after the surface treatment. In the case of a silane coupling agent, the amount of adhesion is determined from the Si intensity (derived from the silane coupling agent) measured by fluorescent X-ray analysis and the main metal element strength of the metal oxide used. The Si intensity measured by this fluorescent X-ray analysis is preferably in the range of 1.0 × 10 ⁻⁵ times or more and 1.0 × 10 ⁻³ times or less of the main metal element strength of the metal oxide used. If it falls below this range, image quality defects such as fog are likely to occur, and if it exceeds this range, density reduction due to an increase in residual potential may easily occur.

Examples of the binder resin contained in the dispersion type undercoat layer coating agent include acetal resins such as polyvinyl butyral, polyvinyl alcohol resin, casein, polyamide resin, cellulose resin, gelatin, polyurethane resin, polyester resin, methacrylic resin, acrylic resin, Known polymer resin compounds such as polyvinyl chloride resin, polyvinyl acetate resin, vinyl chloride-vinyl acetate-maleic anhydride resin, silicone resin, silicone-alkyd resin, phenol resin, phenol-formaldehyde resin, melamine resin, urethane resin, In addition, a charge transporting resin having a charge transporting group and a conductive resin such as polyaniline can be used.
Of these, resins insoluble in the coating solvent for the layer formed on the undercoat layer are preferably used, and phenol resins, phenol-formaldehyde resins, melamine resins, urethane resins, epoxy resins, and the like are particularly preferably used. The ratio between the metal oxide particles and the binder resin in the dispersion type undercoat layer forming coating solution can be arbitrarily set within a range in which desired photoreceptor characteristics can be obtained.

Examples of the method for dispersing the metal oxide particles surface-treated by the above-described method in the binder resin include a media disperser such as a ball mill, a vibration ball mill, an attritor, a sand mill, a horizontal sand mill, an agitator, an ultrasonic disperser, and a roll mill. And a method using a medialess disperser such as a high-pressure homogenizer. Furthermore, examples of the high-pressure homogenizer include a collision method in which the dispersion liquid is dispersed by liquid-liquid collision or liquid-wall collision in a high pressure state, and a penetration method in which the fine liquid is penetrated and dispersed in a high pressure state.
The method of forming the undercoat layer with this dispersion-type undercoat layer coating agent can be performed in the same manner as the method of forming the undercoat layer using the above-described undercoat layer coating agent.

(Organic photosensitive layer: charge transport layer)
Next, the organic photosensitive layer 215 will be described below in this order, divided into the charge transport layer 215b and the charge generation layer 215a.

Examples of the charge transport material used for the charge transport layer 215b include the following.
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) Aromatic tertiary amino compounds such as biphenyl-4-amine, dibenzylaniline, 9,9-dimethyl-N, N-di (p-tolyl) fluoren-2-amine, N, N′-diphenyl-N, Aromatic tertiary diamino compounds such as N′-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 comprised from the said compound in a principal chain or a side chain are mentioned. These charge transport materials can be used alone or in combination of two or more.

  Any binder resin can be used for the charge transport layer, but the binder resin is preferably compatible with the charge transport material and has an appropriate strength.

  Examples of this binder resin include various polycarbonate resins composed of bisphenol A, bisphenol Z, bisphenol C, bisphenol TP, copolymers thereof, polyarylate resins and copolymers thereof, polyester resins, methacrylic resins, acrylic resins Resin, 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 And the like. These resins can be 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 the solvent, but it is usually preferably within the range of 3000 to 300,000 in terms of viscosity average molecular weight. It is more preferably within the range of 200,000 or less.

  The charge transport layer can be 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. , Halogenated aliphatic hydrocarbons, cyclic or linear ethers such as tetrahydrofuran, dioxane, ethylene glycol and diethyl ether, or a mixed solvent thereof can be used. The blending ratio between the charge transport material and the binder resin is preferably in the range of 10: 1 to 1: 5. The 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 preventing 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.

  As specific examples of antioxidants, phenolic antioxidants include 2,6-di-t-butyl-4-methylphenol, styrenated phenol, n-octadecyl-3- (3 ′, 5′- Di-t-butyl-4'-hydroxyphenyl) -propionate, 2,2'-methylene-bis- (4-methyl-6-t-butylphenol), 2-t-butyl-6- (3'-t- Butyl-5'-methyl-2'-hydroxybenzyl) -4-methylphenyl acrylate, 4,4'-butylidene-bis- (3-methyl-6-tert-butyl-phenol), 4,4'-thio- Bis- (3-methyl-6-tert-butylphenol), 1,3,5-tris (4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl) isocyanurate, tetrakis- [methylene- -(3 ', 5'-di-t-butyl-4'-hydroxy-phenyl) propionate] -methane, 3,9-bis [2- [3- (3-t-butyl-4-hydroxy-5- Methylphenyl) propionyloxy] -1,1-dimethylethyl] -2,4,8,10-tetraoxaspiro [5,5] undecane, 3-3 ′, 5′-di-t-butyl-4′- And hydroxyphenyl) stearyl propionate.

  Among hindered amine compounds, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, 1- [2- [ 3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionyloxy] ethyl] -4- [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionyloxy] -2 , 2,6,6-tetramethylpiperidine, 8-benzyl-7,7,9,9-tetramethyl-3-octyl-1,3,8-triazaspiro [4,5] undecane-2,4-dione, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine, dimethyl-1- (2-hydroxyethyl) -4-hydroxy-2,2,6,6-tetramethylpiperidine succinate Condensate, poly [{6- (1,1,3,3-tetramethylbutyl) amino-1,3,5-triazine-2,4-diyl} {(2,2,6,6-tetramethyl- 4-piperidyl) imino} hexamethylene {(2,2,6,6-tetramethyl-4-piperidyl) imino}], 2- (3,5-di-t-butyl-4-hydroxybenzyl) -2- n-Butylmalonate bis (1,2,2,6,6-pentamethyl-4-piperidyl), N, N′-bis (3-aminopropyl) ethylenediamine-2,4-bis [N-butyl-N— (1,2,2,6,6, -pentamethyl-4piperidyl) amino] -6-chloro-1,3,5-triazine condensate and the like.

Among organic sulfur antioxidants, dilauryl-3,3′-thiodipropionate, dimyristyl-3,3′-thiodipropionate, distearyl-3,3′-thiodipropionate, pentaerythritol-tetrakis- (Β-lauryl-thiopropionate), ditridecyl-3,3′-thiodipropionate, 2-mercaptobenzimidazole and the like.
Examples of the organophosphorus antioxidant include trisnonylphenyl phosfte, triphenyl phosfeft, tris (2,4-di-t-butylphenyl) -phosfte, and the like.

  Organic sulfur-based and organic phosphorus-based antioxidants are called secondary antioxidants. When used in combination with phenolic or amine-based primary antioxidants, the antioxidant effect is increased synergistically. Can do.

Examples of the light stabilizer include benzophenone, benzotriazole, dithiocarbamate, and tetramethylpiperidine derivatives.
Examples of the benzophenone light stabilizer include 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, and 2,2′-di-hydroxy-4-methoxybenzophenone.
As the benzotriazole light stabilizer, 2-(-2′-hydroxy-5′methylphenyl-)-benzotriazole, 2- [2′-hydroxy-3 ′-(3 ″, 4 ″, 5 ″) , 6 ″ -tetra-hydrophthalimido-methyl) -5′-methylphenyl] -benzotriazole, 2-(-2′-hydroxy-3′-t-butyl-5′-methylphenyl-)-5-chloro Benzotriazole, 2- (2′-hydroxy-3′-t-butyl-5′-methylphenyl-)-5-chlorobenzotriazole, 2- (2′-hydroxy-3 ′, 5′-t-butylphenyl) -)-Benzotriazole, 2- (2'-hydroxy-5'-t-octylphenyl) -benzotriazole, 2- (2'-hydroxy-3 ', 5'-di-t-amylphenyl-)-benzo Triazole etc. are mentioned
Other light stabilizers include 2,4, di-t-butylphenyl-3 ′, 5′-di-t-butyl-4′-hydroxybenzoate, nickel dibutyl-dithiocarbamate, and the like.

The charge transport layer can be formed by applying a solution prepared 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 can be used.
Silicone oil can also be added to the charge transport layer forming coating solution as a leveling agent for improving the smoothness of the coating film formed by coating. The addition amount is preferably 1 ppm or more and 10,000 ppm or less, more preferably 5 ppm or more and 2,000 ppm or less with respect to the solid content of the charge transport layer.

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

  Depending on the shape and application of the photoreceptor, the coating solution for forming the charge transport layer may be applied by dip coating, ring coating, spray coating, bead coating, blade coating, roller coating, knife coating, curtain, etc. It can be performed using a coating method such as a coating method. Drying is preferably performed by heating after drying at room temperature (10 ° C. or higher and 30 ° C. or lower). The heat drying is desirably performed in a temperature range higher than 30 ° C. and lower than or equal to 200 ° C. for a time in the range of 5 minutes to 2 hours.

(Organic photosensitive layer: charge generation layer)
The charge generation layer 215a is formed by depositing a charge generation material by a vacuum evaporation method or by applying a solution containing an organic solvent and a binder resin.

As the charge generation material, amorphous selenium, crystalline selenium, selenium-tellurium alloy, selenium-arsenic alloy, other selenium compounds; inorganic photoconductors such as selenium alloy, zinc oxide, 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 can be used as long as it is a pigment capable of obtaining characteristics.

  Of the charge generation materials described above, phthalocyanine compounds are preferred. 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 a high quantum efficiency, the absorbed photons can be efficiently absorbed to generate carriers.

Furthermore, 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 °, 160 °, at the Bragg angle (2θ ± 0.2 °) of the X-ray diffraction spectrum using Cukα rays as the charge generation material Crystalline chlorogallium phthalocyanine having diffraction peaks at 25.4 ° and 28.1 ° (3) At 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 having a diffraction peak at a position of at least 9.5 °, 24.2 °, 27.3 °

  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 (multicolor) 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. I can judge.

  Examples of the binder resin used for the charge generation layer include the following. That is, polycarbonate resin such as bisphenol A type or bisphenol Z type and its copolymer, 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, silicon-alkyd resin, phenol-formaldehyde resin, styrene-alkyd resin, poly-N-vinylcarbazole and the like.

  These binder resins can be used alone or in admixture 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. The thickness of the charge generation layer is generally preferably in the range of 0.01 μm to 5 μm, and more preferably 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, and 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 can be 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 linear chains 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 can be used alone or in combination of two or more. When two or more kinds of solvents are mixed and used, any solvent that can dissolve the binder resin as the mixed solvent can be used. 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 substrate side, the charge generation layer is formed using a coating method that easily dissolves the lower layer, such as dip coating. When forming, 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 using a spray coating method or a ring coating method in which the erosion property of the lower layer is relatively less than that of the dip coating, the selection range of the solvent can be expanded.

(Middle layer)
The photosensitive layer in the present invention may be provided with an intermediate layer in addition to the above layers.
As the intermediate layer, for example, when charging the surface of the photoconductor with a charger, the charged electric charge is prevented from being injected from the surface of the photoconductor to the base of the photoconductor as the counter electrode, so that a charging potential cannot be obtained. If necessary, a charge injection blocking layer can be formed between the surface protective layer and the charge generation layer.
As the material for the charge injection blocking layer, general-purpose resins such as the silane coupling agents, titanium coupling agents, organic zirconium compounds, organic titanium compounds, other organic metal compounds, polyesters, and polyvinyl butyral listed above can be used. The film thickness of the charge injection blocking layer is set in the range of about 0.001 μm or more and 5 μm or less in consideration of film forming properties and carrier blocking properties.

[Charging means]
As the charging means in the image forming apparatus of the present invention, conventionally known charging means can be used as long as the surface of the photoreceptor can be uniformly charged.
Specifically, a non-contact corona discharge type corotron, scorotron or the like may be used, or a contact type charging means may be used.
In the case of a contact-type charging unit, the elastic member can be a charging unit by using the elastic roll 20a as shown in FIG. In this case, since the elastic roll 20a needs to be conductive, for example, a metal core is coated with an elastic layer made of a rubber compounded with a conductivity imparting agent such as carbon black, and further, the discharge uniformity is further improved. In order to obtain this, a plurality of elastic layers having different resistivity may be stacked. Further, a coat layer may be provided on the outermost surface in order to prevent charging failure due to surface contamination. More specifically, the core material made of nickel-plated iron, stainless steel, aluminum or the like can be brought into contact with the photosensitive member with a pressing load, and the diameter is 5 mm to 10 mm so that the mass is not unnecessarily heavy. It is preferable that it is about the following. In addition, an elastic layer in which a conductivity-imparting material is blended with a rubber material such as epichlorohydrin rubber, silicone rubber, nitrile rubber, butadiene rubber, EPDM (ethylene-propylene-diene copolymer rubber), or the like is used for such a core material. In order to obtain uniformity, the thickness is preferably about 2 mm to 5 mm. The rubber hardness of the elastic layer is preferably A30 or more and A60 or less in the type A durometer hardness specified in JIS K 6253, and the resistivity is adjusted in the range of 10 ⁶ Ω · cm or more and 10 ¹² Ω · cm or less. It is preferable. Further, the surface roughness of the outermost surface in contact with the photoreceptor is preferably adjusted such that the center line average roughness (Ra) is 10 μm or less, more preferably 5 μm or less. The elastic roll in the charging unit preferably has a configuration in which the outer diameter is about 10 mm or more and 20 mm or less and has an axial length capable of charging the image forming width of the photoconductor.

[Exposure means]
As the exposure means in the image forming apparatus of the present invention, conventionally known exposure means can be used as long as the surface of the photoreceptor can be exposed according to image data.
Specifically, it is an optical lens type that directly projects the reflected light from the document onto the photosensitive member by a light source such as a halogen lamp or a fluorescent tube and an imaging lens, and scans the laser beam modulated by the image data with a polygon mirror. Examples include a laser type for writing on a body, and an LED type for controlling light emission from a plurality of integrated LEDs based on image data and writing on a photoconductor.

[Development means]
As the developing means in the image forming apparatus of the present invention, conventionally known developing means can be used as long as it can supply a developer to the electrostatic latent image formed on the surface of the photoreceptor.
In the case of the developing unit having the elastic roll 42 as shown in FIG. 2, the elastic member can be included in the developing unit. In this case, since it is necessary for the elastic roll 42 to supply the developer to the photoreceptor, for example, a conductivity imparting agent is blended into a metallic tube (sleeve) or a core material (shaft) to increase the resistivity. It is preferable to have a form with an outer diameter of about 20 mm or more and 60 mm or less coated with an elastic layer made of an adjusted rubber material. The material used, the range of resistivity, the surface roughness, and the like are the same as those in the case where the elastic member is a charging unit, but when using a bias voltage to charge the toner, the resistivity should be set. It is preferable to adjust it low. Typical elastic rolls include those used for nonmagnetic one-component contact development.

[Transfer means]
As the transfer means in the image forming apparatus of the present invention, conventionally known transfer means can be used as long as it can transfer the toner image on the photoreceptor onto the recording medium.
In the case of a transfer means having an elastic roll 50a as shown in FIG. 3, the elastic member can be a transfer means. In this case, since the elastic roll 50a needs to have conductivity, for example, a core material made of metal is coated with an elastic layer made of urethane foam whose resistivity is adjusted with a conductivity-imparting agent, and the resistivity is 10 ⁶ Ω. It is preferable that the outer diameter adjusted to about cm to 10 ⁹ Ω · cm is about 10 mm to 20 mm.

[Cleaning means]
As the cleaning means in the image forming apparatus of the present invention, conventionally known cleaning means can be used as long as it can remove deposits such as unfixed toner and paper dust on the photoreceptor. Since the photoreceptor in the present invention has a surface layer with high hardness, a cleaning blade is preferably used from the viewpoint of cleaning performance. The cleaning blade is likely to damage the surface of the photosensitive member and promote wear compared to other cleaning means. However, in the image forming apparatus of the present invention, since the photoconductor of the present invention is used as the photoconductor, it is possible to suppress the occurrence of scratches and wear on the surface of the photoconductor even during long-term use.
In the case of the cleaning means having the elastic roll 62 as shown in FIG. 4, the elastic member can be included in the cleaning means. In this case, for example, the elastic roll 62 preferably has a form in which an outer diameter obtained by coating a core material made of metal with an elastic layer made of urethane foam is about 10 mm or more and 20 mm or less.

[Elastic member]
An elastic roll (elastic member) 70 as shown in FIG. 5 is provided downstream of the cleaning unit 60 and upstream of the charging unit 20 with respect to the rotation direction of the photosensitive member. The shape of the elastic member is a roll shape in FIG. 5, but is not limited to this, and the material can also be pressed against the surface of the photoconductor to relieve stress inside the photoconductor. If it does not specifically limit.

[Control means]
The control means in the image forming apparatus of the present invention is not particularly limited as long as the photosensitive member can be rotated when the image is not formed and the elastic member can be pressed against the surface of the rotating photosensitive member.
Specifically, when no image data is input, the photoconductor is rotated according to the usage history of the photoconductor. At this time, since the toner is not transferred onto a recording medium such as paper, it is preferable to adjust the charging and exposure of the photoconductor so that the toner image on the photoconductor becomes a blank paper.

Next, an image forming mechanism in the image forming apparatus of the present embodiment will be described with reference to FIGS.
As shown in FIGS. 1 to 4, the image forming apparatuses 1 a to 1 d have a photoconductor 10, and in order along the rotation direction of the photoconductor 10, a charging unit 20 (elastic roll 20 a), an exposure unit 30, Developing means 40 (developing means 40a including elastic roll 42), transfer means 50 (elastic roll 50a), cleaning means 60 (cleaning means 60a including elastic roll 62), and control means 80 are provided. 5 also includes an elastic member 70 in addition to the photoreceptor 10, the charging unit 20, the exposure unit 30, the developing unit 40, the transfer unit 50, the cleaning unit 60, and the control unit 80. Have.

The charging unit 20 charges the outer peripheral surface of the photoconductor 10. The exposing unit 30 exposes the outer peripheral surface of the photoconductor 10 charged by the charging unit 20 with light modulated according to the image data, thereby forming an electrostatic latent image corresponding to the image of the image data on the photoconductor 10. Form. The developing unit 40 supplies a developer containing toner to the electrostatic latent image formed on the photoconductor 10 to develop the electrostatic latent image with toner to form a toner image. The transfer unit 50 transfers the toner image on the photoreceptor 10 onto the recording medium P by conveying the recording medium P with the photoreceptor 10 while sandwiching the recording medium P therebetween. The recording medium P is stored in advance in a paper storage unit (not shown), and is conveyed from the paper storage unit by a roller or the like to reach between the photoconductor 10 and the transfer unit 50, so that the photoconductor The toner image on 10 is transferred.
The recording medium P to which the toner image has been transferred is conveyed to an installation location of a fixing device (not shown) by a roller (not shown) and the unfixed toner image is fixed on the recording medium P by the fixing device. . The recording medium P on which the toner image is fixed by the fixing device is discharged to the outside of the image forming apparatuses 1a to 1e by a roller or the like (not shown).
Further, deposits such as unfixed toner and paper dust on the photoconductor 10 are removed from the photoconductor 10 by the cleaning means 60.

Note that at least one selected from the photoconductor 10, the elastic member 70, the control unit 80, the charging unit 20, the exposure device 230, the developing unit 40, and the transfer unit 50 included in the image forming apparatus 1e is as follows. The image forming apparatus 1e main body may be detachably provided, and these detachable apparatuses are collectively referred to as a process cartridge.
In the case of the image forming apparatus 1a shown in FIG. 1, a process cartridge including at least the photosensitive member 10, the control unit 80, and the elastic roll 20a can be used.
In the case of the image forming apparatus 1 b shown in FIG. 2, a process cartridge including at least the photosensitive member 10, the control unit 80, and the developing unit 40 a including the elastic roll 42 can be used.
In the case of the image forming apparatus 1c shown in FIG. 3, a process cartridge including at least the photosensitive member 10, the control unit 80, and the elastic roll 50a can be obtained.
In the case of the image forming apparatus 1d shown in FIG. 4, a process cartridge including at least the photosensitive member 10, the control unit 80, and the cleaning unit 60a including the elastic roll 62 can be obtained.

The image forming apparatus of the present invention may be a so-called tandem machine having a plurality of photoconductors corresponding to the toners of the respective colors. In this case, all the photoconductors have a surface layer containing a Group 13 element and oxygen. It is preferable that the photoconductor has.
Further, the transfer of the toner image is not limited to a method in which the toner image is directly transferred from the photosensitive member to the recording medium, but is an intermediate transfer method in which the toner image is transferred from the photosensitive member to the intermediate transfer member and then transferred from the intermediate transfer member to the recording medium. May be.

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

[Examples 1 to 5]
First, an organic photoreceptor having an undercoat layer 213, a charge generation layer 215a, and a charge transport layer 215b in this order on a conductive substrate 211 shown in FIG. 6 was prepared.
Here, in this embodiment, an organic photoreceptor in which an undercoat layer 213, a charge generation layer 215a, and a charge transport layer 215b are laminated in this order on an aluminum substrate 211 is manufactured according to the procedure described below. did.

-Formation of undercoat layer 213-
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 Nihon 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 is applied to the surface of a cylindrical aluminum substrate 211 having an outer diameter of 84 mm and a length of 340 mm, and is heated and dried at 150 ° C. for 10 minutes. As a result, an undercoat layer 213 having a thickness of 1.0 μm was formed.

-Formation of charge generation layer 215a-
Next, as a charge generation material, a mixture obtained by mixing 1 part by mass of chlorogallium phthalocyanine, 1 part by mass of polyvinyl butyral (trade name: Sleksui BM-S manufactured by Sekisui Chemical Co., Ltd.) and 100 parts by mass of n-butyl acetate The mixture was dispersed with a glass shaker for 1 hour with a paint shaker to obtain a dispersion for forming a charge generation layer.
This dispersion was applied on the undercoat layer 213 by a dipping method and then dried at 100 ° C. for 10 minutes to form a charge generation layer 215a having a thickness of 0.15 μm.

-Formation of charge transport layer 215b-
Next, 2 parts by mass of a compound represented by the following structural formula (1), 3 parts by mass of a polymer compound (viscosity average molecular weight 39,000) represented by the following structural formula (2), 20 parts by mass of chlorobenzene A coating solution for forming a charge transport layer was obtained by dissolving in a part.

This coating solution was applied onto the charge generation layer 215a by an immersion method and heated at 110 ° C. for 40 minutes to form a charge transport layer 215b having a thickness of 20 μm.
As a result, an organic photoreceptor in which the undercoat layer 213, the charge generation layer 215a, and the charge transport layer 215b were laminated in this order on the aluminum substrate 211 was obtained.

The organic photoreceptor was fixed as a laminate 220 on the rotating body 103 shown in FIG. 7, and a surface layer (surface layer 217 in FIG. 6) was formed under the following conditions.
Further, the partition portion 101a in the vacuum vessel 101 had a minimum distance of 2.5 mm from the surface of the rotating organic photoreceptor (laminated body 220).

Next, the inside of the vacuum vessel 101 was evacuated using the exhaust device 111 until the pressure reached about 5.0 Pa.
Thereafter, hydrogen gas (150 sccm) is supplied as a process gas from the process gas supply unit 107 into the vacuum vessel 101 through the supply port 107a, and the discharge surface has a dimension of 350 mm from the high-frequency power supply unit (13.56MHe) 105a. A power of 150 W was supplied to the × 50 mm discharge electrode 105b.

  Next, a mixed gas containing trimethylgallium gas (3.00 sccm) and oxygen gas (10.00 sccm) as a material gas was supplied from the material gas supply unit 109 into the vacuum vessel 101 through the supply port 109a. .

  In the film forming apparatus as described above, the rotating body 103 was rotated at a speed of 200 rpm, and a surface layer having a film thickness of 0.50 μm was formed on the surface of the organic photoreceptor for 30 minutes.

-Surface layer analysis and evaluation-
The thickness of the surface layer was determined by measuring the level difference with the mask portion with a surface roughness meter (manufactured by Tokyo Seimitsu Co., Ltd., Surfcom 550A type).
Further, the mass ratio of the gallium element and oxygen in the surface layer was determined by measuring the film formed on the Si substrate under the same conditions using XPS as described above. As a result, the mass ratio of oxygen to gallium element in the surface layer (= oxygen / gallium element) was 1.2.

The photoconductor obtained as described above is attached to an image forming apparatus (Fuji Xerox Co., Ltd., DocuCenter Color 500), and further, an elastic member (elastic roll) as in each configuration shown in FIGS. 20a, elastic roll 42, elastic roll 50a, elastic roll 62, or elastic roll 70) were attached and remodeled to obtain image forming apparatuses of Examples 1 to 5.
In the image forming apparatuses of Examples 1 to 4, when image formation is not performed, the elastic member is pressed against the surface of the photoreceptor at a pressure of 5 g / cm and a rotation speed of 50 rpm, and the photoreceptor is rotated 100 times as it is. I let you.
In the image forming apparatus of Example 5, the elastic member was pressed against the surface of the photoreceptor at a pressure of 2.5 g / cm and a rotation speed of 50 rpm while the image was formed, and the photoreceptor was rotated 100 times. .

  Here, the detail of the elastic roll 20a, the elastic roll 42, the elastic roll 50a, the elastic roll 62, and the elastic roll 70 used in Examples 1-5 is shown below.

-Example 1: Elastic roll 20a
Core material: Cylindrical stainless steel with a diameter of 8 mm and length of 320 mm Elastic layer: Epichlorohydrin rubber is blended with ionic conductive agent and carbon black, 3 mm thick, covering both ends of the core material leaving 8 mm each, 14 mm in diameter It was. The resulting elastic layer had a rubber hardness of A60 and a volume resistivity of 10 ⁹ to 10 ¹⁰ Ω · cm.

Example 2: Elastic roll 42
Core material: hollow cylindrical stainless steel material with a diameter of 25 mm, a thickness of 0.5 mm, and a length of 350 mm Elastic layer: EPDM is blended with an ionic conductive agent and carbon black, with a thickness of 1.5 mm, each end of the core material being 15 mm Each was left behind and coated to a diameter of 28 mm. The resulting elastic layer had a rubber hardness of A60 and a volume resistivity of 10 ⁶ to 10 ⁸ Ω · cm.

-Example 3: Elastic roll 50a
Core material: Cylindrical stainless steel with a diameter of 8 mm and a length of 320 mm Elastic layer: Ionic conductive agent and carbon black are blended in urethane foam, and the thickness is 6 mm. It was. The volume resistivity of the obtained elastic layer was 10 ⁶ to 10 ⁸ Ω · cm.

Example 4: Elastic roll 62
Core material: Cylindrical stainless steel material with a diameter of 6 mm and a length of 320 mm Elastic layer: An ionic conductive agent and carbon black are blended with foamed urethane. The thickness is 7 mm and both ends of the core material are covered by 8 mm each, and the diameter is 20 mm. It was. The volume resistivity of the obtained elastic layer was 10 ⁶ to 10 ⁸ Ω · cm.

Example 5: Elastic roll 70
Core material: Cylindrical stainless steel material with a diameter of 6 mm and a length of 320 mm Elastic layer: EPDM is blended with an ionic conductive agent and carbon black, covered with 15 mm each of both ends of the core material, with a thickness of 5 mm. did. The resulting elastic layer had a rubber hardness of A55 and a volume resistivity of 10 ⁶ to 10 ⁸ Ω · cm.

-Evaluation-
(Evaluation of residual potential)
The residual potential of the photoreceptor was measured at the start of use, one day later, and one week later using (Trek Co., Model 344 surface potentiometer).
The results are shown in Table 1.

(Evaluation of potential unevenness)
Unevenness (= maximum value−minimum value) of the surface potential at the time of charging of the photoreceptor was measured at the start of use, one day later, and one week later using (manufactured by Trek 344 type surface potential meter).
Note that the number of measurement points on the photoconductor was 42 in total, that is, every 50 mm in the axial direction of the photoconductor and every 60 ° in the circumferential direction.
The results are shown in Table 1.

(Evaluation of density unevenness)
Using the image forming apparatus, 50,000 sheets were printed with a halftone having an image density of 20%, and the density unevenness of the image was evaluated.
The results are shown in Table 1.

(Evaluation of image flow)
Using an image forming apparatus, 50,000 sheets were printed with a halftone having an image density of 20% under high humidity conditions (28 ° C., 85% RH), and image flow was evaluated.
The results are shown in Table 1.

(Evaluation of photoreceptor wear)
Using an image forming apparatus, 50,000 sheets were printed with a halftone having an image density of 20%, and the amount of wear on the surface layer of the photoreceptor was measured by a light interference method.
The results are shown in Table 1.

[Comparative Example 1]
An image forming apparatus having the structure shown in FIG. 5 was obtained in the same manner as in Example 5 except that the photoconductor used in Example 5 was replaced with one having no surface layer.

[Comparative Example 2]
In the image forming apparatus having the configuration shown in FIG. 5 used in Example 5, an image forming apparatus was obtained in the same manner as Example 5 except that the elastic roll 70 and the control means 80 were not provided.

[Comparative Examples 3 to 5]
The photoconductor used in Comparative Example 2 (the same photoconductor as used in Examples 1 to 5) has the same configuration as that of Comparative Example 2 except that the photoconductor was subjected to the following treatment. An image forming apparatus was obtained.

Comparative Example 3: A photoreceptor with a surface layer formed thereon was rubbed with alcohol and then blown with nitrogen gas. Comparative Example 4: A photoreceptor with a surface layer formed was manufactured by Nippon Emerson Co., Ltd. , Branson B8510J-DTH type ultrasonic cleaner, ultrasonically cleaned in pure water. Comparative Example 5: Photoconductor with surface layer formed, annealed at 60 ° C. for 1 week

  In the image forming apparatuses of Comparative Examples 1 to 5, the same evaluations as in Examples 1 to 5 were performed. The results are shown in Table 2 below.

From Table 1 and Table 2, the following can be understood.
That is, according to Examples 1 to 5, it can be seen that the residual potential of the photoreceptor decreases with time and the wear amount is small. It can also be seen that image flow does not occur in a high-humidity environment and density unevenness is small.
According to Comparative Example 1, it can be seen that the residual potential of the photoconductor is small and there is no problem with uneven density and image flow. However, since the photoconductor does not have a surface layer, the wear amount is large, and the lifetime of the photoconductor is large. Is short.
According to Comparative Example 2, since the image forming apparatus does not have an elastic member, it can be seen that the residual potential of the photoconductor does not decrease with time and density unevenness occurs after one day.
According to Comparative Examples 3 to 5, it can be seen that the residual potential of the photoconductor does not decrease with time, and density unevenness occurs after one day. This shows that the internal stress is not uniformly relieved by various processes applied to the surface layer of the photoreceptor.

It is a schematic sectional drawing which shows an example of a structure of the image forming apparatus of this embodiment. It is a schematic sectional drawing which shows an example of a structure of the image forming apparatus of this embodiment. It is a schematic sectional drawing which shows an example of a structure of the image forming apparatus of this embodiment. It is a schematic sectional drawing which shows an example of a structure of the image forming apparatus of this embodiment. It is a schematic sectional drawing which shows an example of a structure of the image forming apparatus of this embodiment. It is a schematic sectional drawing which shows an example of the laminated constitution of the photoreceptor suitable for this embodiment. It is a schematic diagram which shows an example of the film-forming apparatus used for formation of the surface layer in this embodiment.

Explanation of symbols

1a to 1e Image forming apparatuses 10, 210 Photoconductor 20 Charging means 30 Exposure means 40 Developing means 50 Transfer means 60 Cleaning means 20a, 42, 50a, 62, 70 Elastic roll 80 Control means 100 Film forming apparatus 101 Vacuum container 101a Partition 103 Rotating Unit 105 Discharge Unit 105a High Frequency Power Supply Unit 105b Discharge Electrode 107 Process Gas Supply Unit 107a Supply Port 109 for Supplying Process Gas Material Gas Supply Unit 109a Supply Port 111 for Supplying Material Gas 111 Exhaust Device 111a Exhaust Port 211 Conductive Substrate 213 Undercoat layer 215 Organic photosensitive layer 215a Charge generation layer 215b Charge transport layer 217 Surface layer 220 A laminate in which an organic photosensitive layer is provided on a conductive substrate

Claims (7)

  A photosensitive member having an organic photosensitive layer and a surface layer containing a Group 13 element and oxygen on a conductive substrate, a charging unit, an exposure unit, a developing unit, a transfer unit, a cleaning unit, an elastic member, and An image forming apparatus comprising: a control unit that rotates the photosensitive member and presses the elastic member against a surface of the rotating photosensitive member.   The elastic member is included in any one of the charging unit, the developing unit, the transfer unit, and the cleaning unit, and the control unit rotates and rotates the photosensitive member when image formation is not performed. The image forming apparatus according to claim 1, wherein the elastic member is pressed against a surface of the photoconductor.   The charging means is a non-contact type, and the elastic member is a roll made of a rubber-like elastic body. The roll is pressed against the photoconductor by the control means and rotates in contact with the photoconductor. The image forming apparatus according to claim 1.   The image forming apparatus according to claim 1, wherein the group 13 element in the surface layer is gallium.   The image forming apparatus according to claim 1, wherein a thickness of the surface layer is 0.05 μm or more and 1.0 μm or less.   6. The elastic member according to claim 1, wherein the elastic member is pressed by a force of 1 g / cm or more and 10 g / cm or less per unit length in the rotation axis direction of the photoconductor. Image forming apparatus.   For a photoreceptor having an organic photosensitive layer and a surface layer containing a Group 13 element and oxygen on a conductive substrate, the elastic member is 1 g / cm or more per unit length in the rotational axis direction of the photoreceptor. A method for processing a photosensitive member, wherein pressing is performed with a force of 10 g / cm or less.

Images