JP2010197734A - Image forming method using electrophotographic photoreceptor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming method that stably outputs a security image and has highly homogeneous image density by suppressing an electrostatic charge ghost before transfer and oxidation of an electrophotographic photoreceptor surface. <P>SOLUTION: In the electrophotographic photoreceptor, a photoconductive layer made of hydrogenation amorphous silicon containing boron atoms on a substrate, and a surface layer made of hydrogenation amorphous silicon carbide are sequentially formed. In the distribution of the boron atoms, the content of them is maximum on the substrate side in the thickness direction of the photoconductive layer, and decreases toward the surface side continuously in a linear or curved shape. When, of the pre-exposure quantity radiated to the electrophotographic photoreceptor in the pre-exposure process, the pre-exposure quantity absorbed in a region where atom density of the boron atoms is ≥9.64×10<SP>15</SP>atoms/cm<SP>3</SP>is assumed to be A(μJ/cm<SP>2</SP>), a predetermined formula is established, and the sum of the atom density of silicon atoms and the atom density of carbon atoms is ≥6.60×10<SP>22</SP>atoms/cm<SP>3</SP>in the surface layer. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  INDUSTRIAL APPLICABILITY The present invention is used for an image forming apparatus such as an electrophotographic system or an electrostatic recording system, such as an electrophotographic system or an electrostatic recording system, in which a developer is attached to an electrostatic latent image formed on an electrophotographic photoreceptor for visualization. The present invention relates to an image forming method.

  As an image forming method using an electrophotographic photoreceptor, for example, a charging process for imparting electric charge to the electrophotographic photoreceptor, and a latent image for forming an electrostatic latent image on the electrophotographic photoreceptor by performing image exposure There is known an image forming method including a forming step, a developing step for visualizing an electrostatic latent image with toner, a transferring step for transferring the latent image onto a transfer material, and a cleaning step for collecting residual toner.

  Further, during the period from the development process to the transfer process, pre-transfer charging is performed by applying DC discharge or AC discharge having the same polarity as the toner charge polarity on the electrophotographic photosensitive member, thereby enhancing the toner charge amount. It is known that image transfer stability is improved.

  Various improvements for improving the image quality have been proposed for the electrophotographic photoreceptor and the image forming method used in such an image forming method.

  For example, a technology that provides a dispersion-type photosensitive layer in which a charge-generating material is dispersed in a binder containing a charge transport material and a binder resin, and defines the distance at which static elimination light enters the photosensitive layer and the film thickness ratio of the photosensitive layer Is disclosed. This makes it possible to improve the sensitivity of the dispersion type photoreceptor and the stability of the charged voltage in an electrophotographic process that is repeatedly used (see Patent Document 1).

  In addition, it has means for irradiating analog light for analog images and means for irradiating digital light for digital images, and image formation is performed for 1 second on the photosensitive region exposed to light rays for digital images. Control means that do not perform are disclosed. This makes it possible to realize an analog-digital integrated electrophotographic image forming method without ghost (see Patent Document 2).

  Further disclosed is an electrophotographic apparatus having an image exposure of 670 nm or more, a charge removal light wavelength of 620 nm or more, and a photoreceptor surface potential control means for controlling the photoreceptor surface potential immediately before or immediately below the discharge light to -100 V or more. Yes. As a result, ghosts can be effectively prevented, and as a result, the life of the photosensitive member can be extended (see Patent Document 3).

  Furthermore, it is composed of a photoconductive layer sensitive to the light wavelength irradiated by the image exposure means, and a photoconductive layer having a lower sensitivity to the exposure wavelength than the photoconductive layer and sensitive to the light wavelength of the static elimination light source. An optical backside recording photoreceptor is disclosed. As a result, in the backside recording method, high responsiveness to image exposure is exhibited, and an image having a high image density can be obtained only by the charge-removing light, so that the image quality can be improved (see Patent Document 4).

  Further, an electrophotographic apparatus is disclosed in which the localized level density in the photoconductive layer, the electric field applied to the photoconductor, and the moving speed of the surface of the photoconductor are controlled so as to have specified values. As a result, the ghost can be reduced without lowering the charging ability, so that high-quality image formation is possible (see Patent Document 5).

  In addition, in the portion where the light of the photoconductive layer is incident, the characteristic energy of the exponential function obtained from the subband gap optical absorption spectrum, the local state density are set within a predetermined range, and the wavelength of the static elimination light and the light intensity are A defined electrophotographic method is disclosed. As a result, since the ghost can be reduced without deteriorating the charging ability and the potential shift, a high-quality image can be output (see Patent Document 6).

Japanese Patent Laid-Open No. 01-310383 Japanese Patent Laid-Open No. 06-130769 Japanese Patent Laid-Open No. 08-022229 Japanese Patent Laid-Open No. 06-083143 Japanese Patent Laid-Open No. 06-266138 JP 08-179663 A

  In recent years, digital electrophotographic devices and color electrophotographic devices, which have been widely used, frequently make copies of not only text originals but also photographs, pictures, and design images, and further improvement in image uniformity is required.

  As an electrophotographic photoreceptor used in such an electrophotographic apparatus, a hydrogenated amorphous silicon (hereinafter referred to as “a-Si”) photoreceptor is known.

  When an a-Si photosensitive member is used as the electrophotographic photosensitive member, an afterimage phenomenon (hereinafter referred to as “ghost”) in which the exposure history of the previous circumference appears may occur in the image.

  Conventionally, for this ghost, the entire surface of the electrophotographic photosensitive member is exposed before main charging (hereinafter referred to as “pre-exposure”), and the residual electrostatic latent is caused by a large amount of carriers generated in the photoconductive layer. Improvements have been made by reducing the effect of the carrier on the image on the image. In addition, the photoconductive layer of the a-Si photosensitive member has a plurality of layer structures, and a layer design in which functions are separated into a layer that focuses on improving the traveling property of electrons and a layer that focuses on improving the traveling property of holes is performed. I have been. The conventional ghost has been improved while maintaining other electrophotographic characteristics by adjusting the photoconductive layer on the free surface side of the electrophotographic photoreceptor so that the pre-exposure is substantially absorbed.

  However, in recent years, interest in security of output images has been increasing in the market. When a security image is output, a normal security image may not be output due to a slight ghost that has not been a problem in the past.

  In particular, when the a-Si photosensitive member is used in an electrophotographic process having a pre-transfer charging step between the development step and the transfer charging step for the purpose of improving the transfer stability of the toner image, the above-described ghost improvement is performed. However, sufficient effects may not be obtained, and improvements are required.

  In addition, by repeatedly outputting an image using an a-Si photoreceptor in an electrophotographic process having a pre-transfer charging step, image defects such as ghosting and image density reduction may occur depending on image output conditions. That correspondence is also sought.

  The causes of these image defects are various, but when attention is paid to the electrophotographic photoreceptor, the cause is often on the surface of the electrophotographic photoreceptor.

  As an example, there is a phenomenon (hereinafter referred to as “surface adhesion”) in which a substance related to image formation adheres to the surface of the electrophotographic photoreceptor. This surface adhesion is removed by a cleaning step under normal process conditions. However, in the electrophotographic process using a toner with a very low melting point and the contact pressure between the electrophotographic photosensitive member and the cleaning member being extremely lowered, the surface of a character document with a low printing rate is repeatedly output. Adhesion may occur. Examples of this deposit include paper powder, a resin component and a wax component contained in the toner.

  Another example is a phenomenon in which the surface layer formed on the free surface side of the electrophotographic photoreceptor is altered. This alteration phenomenon is also suppressed in the normal use environment and use conditions by removing the altered layer by the rubbing action in the cleaning process. However, if the current, voltage, and charged product applied to the electrophotographic photosensitive member are greatly changed due to an abnormality in the electrophotographic apparatus or a sudden change in the surrounding environment, or if the cleaning conditions are largely changed, it is caused by that. An oxide layer may remain on the surface of the electrophotographic photoreceptor.

  Therefore, for the purpose of the present invention, the main charging step imparts a positive charge to the electrophotographic photosensitive member, and a negative charge is imparted to the downstream side of the developing step and the upstream side of the pre-exposure step. An object of the present invention is to provide an image forming method capable of stably outputting a security image by suppressing a ghost generated at the time of outputting a security image in an electrophotographic process having a charging step.

  The inventors of the present invention first studied to reduce ghosts in an electrophotographic process having a charging step that imparts a negative charge downstream of the development step and upstream of the pre-exposure step. .

  As a result, in the electrophotographic process using the pre-transfer charging step in which a charge having a polarity opposite to the positive charge applied in the main charging step, that is, a negative charge, is applied, the conventional ghost and the ghost caused by the pre-transfer charging ( (Hereinafter referred to as “pre-transfer charging ghost”). That is, it has been found that the ghost finally generated in the image is a combination of the above-described conventional ghost and the pre-transfer charging ghost. Therefore, we inferred the difference in generation mechanism between conventional ghosts and pre-transfer charged ghosts.

  First, a conventional ghost generation mechanism in a positively charged electrophotographic photoreceptor in which the above-described photoconductive layer is functionally separated into two layers will be described with reference to FIG. In this ghost generation mechanism, both electrons and holes generated by image exposure are involved, but in the following, description will be given focusing on electrons.

  First, a positive charge is imparted to the electrophotographic photoreceptor by the main charging step. When an electrostatic latent image is formed by image exposure, the irradiated image exposure is absorbed by the photoconductive layer, and holes and electrons are generated (FIG. 7A). Some of the holes and electrons generated in this photoconductive layer recombine and disappear, but some of the generated electrons combine with the positive charge imparted by the main charging process to form an electrostatic latent image. Is formed (FIG. 7B). Some of the electrons generated by image exposure are trapped by defects and accumulated in the photoconductive layer (FIG. 7C). Therefore, in the photoconductive layer, more electrons are accumulated in the portion irradiated with the image exposure than in the portion not irradiated with the image exposure when forming the latent image.

  A part of the electrons accumulated in the photoconductive layer is then re-excited, and when a potential difference occurs due to the application of positive charges in the next main charging process, it moves to the surface of the electrophotographic photosensitive member, and the main charging process Combines with the applied positive charge. For this reason, the portion where more electrons are accumulated has less positive charge on the surface of the electrophotographic photosensitive member after the main charging process, and the portion where no image exposure is irradiated and the image exposure are irradiated when the latent image is formed. A potential difference is generated between the portions (FIG. 7D). It is presumed that this potential difference is visualized by the toner as a conventional ghost.

  Next, the mechanism of generation of the pre-transfer charging ghost is described as follows. The positively charging electrophotographic photosensitive member is replaced with an analog electrophotographic apparatus or a BAE (electrophotographic process in which a toner image is formed on a portion not exposed to image exposure). The case where it is used in a digital electrophotographic apparatus will be described with reference to FIG. FIG. 8 shows only those involved in the generation of the pre-transfer charging ghost.

  In the case of an analog electrophotographic apparatus, a toner image is formed on a portion where image exposure is not irradiated on the electrophotographic photoreceptor. In addition, when used in a digital electrophotographic apparatus of IAE (electrophotographic process in which a toner image is formed on a portion irradiated with image exposure), a ghost similar to the pre-transfer charging ghost generated in the BAE is transferred and charged. It may occur due to the cause.

  First, the state in the second photoconductive layer when a positive charge is imparted to the electrophotographic photoreceptor by the main charging step and the electrostatic latent image is formed by image exposure is the same as that of the ghost described above (FIG. 7 (b)).

  Next, when the toner image is formed on the electrophotographic photosensitive member using the negatively charged toner from the formed electrostatic latent image, a toner image is formed in a portion not irradiated with image exposure (FIG. 8A). . For the reasons described above, a negative charge having a reverse polarity to the positive charge applied in the main charging process is applied in the pre-transfer charging process. Thereby, the charge is mainly supplied to the toner in the portion where the image exposure is not irradiated. However, since a negative charge is supplied to the electrophotographic photoreceptor itself in the portion irradiated with the image exposure, the electrons imparted in the pre-transfer charging process are accumulated in the electrophotographic photoreceptor (FIG. 8B). )). As a result, compared to the case without the pre-transfer charging step, the number of electrons accumulated in the electrophotographic photoreceptor is larger in the portion irradiated with the image exposure than in the portion not irradiated with the image exposure. After the toner image is transferred to the transfer material, if a positive charge is applied to the electrophotographic photoreceptor again by the main charging process, the portion exposed to image exposure has accumulated more electrons, so the main charge More positive charges imparted by the process are erased (FIG. 8C). As a result, the surface potential after the main charging step is lowered in the portion irradiated with image exposure on the front periphery. For this reason, the potential difference between the portion irradiated with the image exposure and the portion not irradiated with the image exposure becomes larger than that without the pre-transfer charging step (FIG. 8D). As a result, the density difference in the image becomes more prominent than the conventional ghost. This is presumably because the pre-transfer charging ghost is added to the conventional ghost.

  Studies were made on the accumulation of electric charge in the electrophotographic photosensitive member which causes this pre-transfer charging ghost. As a result, it has been found that the charging ghost before transfer may become prominent when the layer structure of the photoconductive layer of the electrophotographic photoreceptor is made plural. From this, it is presumed that the charges accumulated in the electrophotographic photoreceptor are accumulated at the interface portion between the plurality of photoconductive layers.

  From the above, the conventional ghost is generated by accumulating electrons generated by image exposure in the photoconductive layer. On the other hand, the pre-transfer charging ghost is further provided with a negative charge having a reverse polarity to the positive charge applied in the main charging process by the pre-transfer charging process, so that electrons are transferred from the first photoconductive layer and the second photoconductive layer. It is presumed that it occurs by accumulating at the interface. Thus, since the generation mechanism of the conventional ghost and the pre-transfer charging ghost are different, it is considered that countermeasures are required for each.

  Therefore, in order to improve the conventional ghost, it is considered effective to improve the traveling property of the carrier generated by image exposure. At the same time, it is considered effective to irradiate the entire surface of the electrophotographic photoreceptor with pre-exposure to reduce the influence of the carrier on the image during the electrostatic latent image remaining in the photoconductive layer.

  In addition, in order to improve the pre-transfer charging ghost, it is presumed that it is effective to reduce the electrons accumulated at the interface between the first photoconductive layer and the second photoconductive layer.

  In the present invention, since the above-mentioned interface is not formed by forming a single layer of the photoconductive layer, accumulation of electrons in the photoconductive layer due to pre-transfer charging is unlikely to occur, and pre-transfer charging ghosts can be reduced. It is.

  Further, in the present invention, the content of boron atoms in the photoconductive layer is the maximum concentration on the substrate side in the film thickness direction of the photoconductive layer, and continuously in a linear or curved manner toward the surface side. The distribution is decreasing. With this configuration, holes generated by image exposure can easily travel to the substrate side, while electrons generated by image exposure easily travel to the surface side. As a result, ghosts caused by carriers generated by image exposure can also be reduced.

In the present invention, a pre-exposure with a predetermined light amount is made to reach a photoconductive layer region in which the atomic density of boron atoms is 9.64 × 10 ¹⁵ atoms / cm ³ or more. The reason why the ghost is improved by doing so is presumed as follows.

  In the present invention, as described above, accumulation of electrons in the photoconductive layer due to pre-transfer charging is suppressed by not forming an interface in the photoconductive layer. However, it is assumed that some electrons remain in the photoconductive layer. As the electron content in the photoconductive layer increases as the boron atom content increases, the traveling property is inhibited. Therefore, it is considered that the residual electrons are distributed more in the boron atom-containing region having a predetermined concentration or more. In order to cancel the residual electrons, it is necessary to generate holes by pre-exposure near the residual electrons and on the substrate side.

Therefore, it is considered necessary to control the pre-exposure light amount distribution in the photoconductor layer thickness direction in order to efficiently cancel the residual electrons of the above-described distribution, and the pre-exposure light amount distribution is the same as the boron atom content distribution. It is inferred that there is a close relationship. A pre-exposure light amount distribution capable of efficiently canceling residual electrons by absorbing a pre-exposure of a predetermined light amount in a photoconductive layer region having an atomic density of boron atoms of 9.64 × 10 ¹⁵ atoms / cm ³ or more It is considered that the relationship of boron atom content distribution is prescribed.

  On the other hand, it is also necessary to suppress ghost and image density reduction that occur when image formation is repeatedly performed by an electrophotographic process having a pre-transfer charging step.

  Therefore, the present inventors have further studied to solve the ghost and image density reduction that occur when the above-described repeated image formation is performed.

  As a result, when image formation is repeatedly performed under the above-described image output conditions, when the above-described surface adhesion occurs, the substantial pre-exposure light amount incident on the electrophotographic photosensitive member is less than that at the start of use of the electrophotographic apparatus. Therefore, a ghost is generated at the surface adhesion portion. In addition, if the oxide layer formed on the surface layer remains, the substantial amount of pre-exposure incident on the electrophotographic photoreceptor increases compared to when the electrophotographic apparatus is used. Found that occurs.

  The mechanism of generation of ghost due to image density reduction and surface adhesion due to the remaining oxide layer on the surface of the electrophotographic photoreceptor is assumed as follows.

  First, the mechanism of occurrence of a decrease in image density due to the remaining oxide layer on the surface of the electrophotographic photoreceptor will be described.

The surface of the electrophotographic photoreceptor is altered by the charged product, and an oxide layer is formed. Since the refractive index of the oxide layer is an intermediate value between the refractive index of air and the refractive index of the a-SiC surface layer, the oxide layer functions as an antireflection film. For this reason, if the formed oxide layer is not sufficiently removed by the cleaning member, the reflectance of the pre-exposure irradiated on the surface of the electrophotographic photoreceptor is lowered in the remaining portion of the oxide layer. Therefore, even if the electrophotographic photoreceptor is irradiated with a predetermined amount of pre-exposure light, the amount of pre-exposure light incident on the electrophotographic photoreceptor increases substantially as the remaining portion of the oxide layer increases. As a result, the amount of pre-exposure that reaches the photoconductive layer region where the atomic density of boron atoms is 9.64 × 10 ¹⁵ atoms / cm ³ or more is greater than the set amount of light at the start of use of the electrophotographic apparatus, and is generated by pre-exposure. The number of careers to increase. As a result, it is presumed that the image density may decrease because more positive charges applied in the next main charging step are erased.

  Next, a ghost generation mechanism due to surface adhesion to the electrophotographic photoreceptor will be described.

A large number of polar groups are present in the oxide layer formed by the alteration of the surface of the electrophotographic photoreceptor by the charged product. Therefore, if the formed oxide layer is not sufficiently removed by the cleaning member, the surface free energy on the surface of the electrophotographic photoreceptor also increases. As described above, when an image is repeatedly output in a state where the surface free energy on the surface of the electrophotographic photoreceptor is high, surface adhesion may occur on the electrophotographic photoreceptor. When surface adhesion occurs on the electrophotographic photoreceptor, the light reflectance on the surface of the electrophotographic photoreceptor increases when pre-exposure is applied due to surface adhesion. For this reason, even if the electrophotographic photosensitive member is irradiated with a predetermined pre-exposure light amount, the pre-exposure light amount incident on the electrophotographic photosensitive member substantially decreases as the surface adhesion proceeds. As a result, a deviation from the pre-exposure light amount that reaches the photoconductive layer region where the atomic density of boron atoms set at the start of use of the electrophotographic apparatus reaches 9.64 × 10 ¹⁵ atoms / cm ³ or more occurs, so that the ghost is improved. It is inferred that it may be insufficient.

  The mechanism that the image density partially decreases in the longitudinal direction of the electrophotographic photosensitive member due to the remaining oxide layer formed on the surface of the photosensitive member for electrophotography, and the longitudinal direction of the electrophotographic photosensitive member due to surface adhesion partially. Next, a mechanism for generating a ghost will be described.

  In an electrophotographic process in which the contact pressure between the electrophotographic photosensitive member and the cleaning member is extremely reduced, a region where the frictional force between the surface of the electrophotographic photosensitive member and the cleaning member is low is likely to occur. In such a region having a low rubbing force, removal of the oxide layer formed on the surface of the electrophotographic photoreceptor becomes insufficient, and the oxide layer remains. Further, surface adhesion to the surface of the electrophotographic photoreceptor is likely to occur. As a result, only the remaining portion of the oxide layer and the surface adhesion generation portion are deviated from the pre-exposure conditions set at the start of use of the electrophotographic apparatus. For this reason, it is presumed that image density lowering and ghost are partially generated in the longitudinal direction of the electrophotographic photosensitive member.

  From this, the present inventors can suppress the deterioration of image density and ghost that are partially generated in the longitudinal direction of the electrophotographic photoreceptor by suppressing the alteration of the a-SiC surface layer due to the charged product. I thought it was. Therefore, the present inventors have intensively studied the a-SiC surface layer excellent in oxidation resistance due to the charged product.

  As a result, it has been found that by making the sum of the atomic densities of silicon atoms and carbon atoms constituting the a-SiC surface layer larger than a predetermined value, there is a great effect on the above-described problem.

As described above, the amount of pre-exposure reaching the photoconductive layer region where the atomic density of boron atoms is 9.64 × 10 ¹⁵ atoms / cm ³ or more is set within a predetermined range, and the a-SiC surface layer is configured. It has been found that by making the sum of the atomic densities of silicon atoms and carbon atoms greater than a predetermined value, the present invention has been completed.

That is, the present invention provides a pre-exposure step for removing at least the electrophotographic photoreceptor on the electrophotographic photoreceptor, a main charging step for imparting a positive charge to the electrophotographic photoreceptor, and the electrophotographic An image exposure process for forming a latent image on the photoreceptor, a development process for visualizing the electrostatic latent image with toner, and a negative charge at a location downstream of the development process and upstream of the pre-exposure process. An image forming method having a charging step of imparting
The electrophotographic photoreceptor is obtained by sequentially forming a photoconductive layer made of hydrogenated amorphous silicon containing boron atoms and a surface layer made of hydrogenated amorphous silicon carbide on at least a substrate,
The boron atom has a distribution in which the content thereof is the maximum concentration on the substrate side in the film thickness direction of the photoconductive layer, and continuously decreases linearly or curvedly toward the surface side,
The surface layer has a sum of atomic density of silicon atoms and atomic density of carbon atoms of 6.60 × 10 ²² atoms / cm ³ or more,
Of the pre-exposure light amount irradiated to the electrophotographic photoreceptor in the pre-exposure step, the pre-exposure light amount that reaches the region where the atomic density of boron atoms is 9.64 × 10 ¹⁵ atoms / cm ³ or more is defined as A (μJ / Cm ² ), the following formula (1) is satisfied.
Formula (1) −12.0 ≦ Ln (A) ≦ −4.5

According to the present invention, in the film thickness direction of the photoconductive layer, the content of boron atoms is the maximum concentration on the substrate side, and the distribution continuously decreases linearly or curvedly toward the surface side. The pre-exposure light amount and the layer structure of the electrophotographic photosensitive member are adjusted so that the pre-exposure light amount that reaches the region where the atomic density of boron atoms reaches 9.64 × 10 ¹⁵ atoms / cm ³ or more becomes a predetermined value. Thus, while maintaining the charging ability, a charging step for applying a negative charge having a polarity opposite to the positive charge applied in the main charging step at the downstream side of the developing step and the upstream side of the pre-exposure step. Even when it is performed, it is possible to suppress the ghost.

At the same time, by providing an a-SiC surface layer with high atomic density on the free surface side of the electrophotographic photoreceptor, it is possible to suppress the formation of partial oxide layers and surface adhesion in the longitudinal direction of the electrophotographic photoreceptor. It becomes. For this reason, it is possible to suppress a partial reduction in image density in the longitudinal direction of the electrophotographic photosensitive member due to the formation of an oxide layer and adhesion to the surface, and the generation of ghosts and pre-transfer charged ghosts. By combining these, it is possible to maintain the ghost reduction effect for a long period of time by controlling the amount of pre-exposure light that reaches the region where the atomic density of boron atoms reaches 9.64 × 10 ¹⁵ atoms / cm ³ or more. It becomes.

For these reasons, the amount of pre-exposure for reaching an area where the atomic density of boron atoms is 9.64 × 10 ¹⁵ atoms / cm ³ or more is controlled to a predetermined value, and an a-SiC surface layer having a high atomic density is formed. By providing, an image forming method capable of stably outputting a security image can be obtained.

1 is a schematic configuration diagram illustrating an example of an electrophotographic apparatus according to the present invention. 1 is a schematic cross-sectional view of a layer configuration showing an example of an electrophotographic photoreceptor according to the present invention. It is a schematic diagram of an example of the plasma CVD apparatus used for preparation of the electrophotographic photoreceptor according to the present invention. It is the schematic of the measuring device used by surface adhesion evaluation. (A) It is a schematic sectional drawing which shows arrangement | positioning of the cylindrical base | substrate used at the time of sample preparation, and a sample. (B) It is a schematic side view which shows the cylindrical base | substrate used at the time of sample preparation, and arrangement | positioning of a sample. Test chart used in ghost evaluation. It is explanatory drawing for demonstrating the mechanism of the conventional ghost. It is explanatory drawing for demonstrating the mechanism of the charging ghost before transfer.

  As described above, in the present invention, the photoconductive layer contains boron atoms, and the content thereof is the maximum concentration on the substrate side in the film thickness direction of the photoconductive layer, and is linear or linear toward the surface side. It is characterized by a distribution that continuously decreases in a curved line.

  Thus, the hole traveling property can be improved in the region on the surface side of the photoconductive layer, and the electron traveling property can be improved in the region on the substrate side of the photoconductive layer. Therefore, the holes generated by the image exposure can easily travel to the substrate side, while the electrons generated by the image exposure easily travel to the surface side. As a result, it is possible to reduce ghosts caused by charges generated by image exposure, and to realize a more uniform image density.

As described above, in the image forming method of the present invention, the atomic density of boron atoms is 9.64 × 10 ¹⁵ atoms / cm ³ in the pre-exposure light amount irradiated to the electrophotographic photoreceptor in the pre-exposure step. When the pre-exposure light amount reaching the above photoconductive layer region is A (μJ / cm ² ), Ln (A) satisfies −12.0 or more and −4.5 or less.

  Pre-transfer charging ghost reduces the amount of charge accumulated in the photoconductive layer by making the distribution of boron atoms contained in the photoconductive layer a distribution that does not form the interface between the first photoconductive layer and the second photoconductive layer. can do.

However, since some of the charges remain in the photoconductive layer, in order to further improve the pre-transfer charging ghost, it is necessary to cancel the charge remaining in the photoconductive layer by pre-exposure. Therefore, by setting the pre-exposure light quantity Ln (A) absorbed by the photoconductive layer region having an atomic density of boron atoms of 9.64 × 10 ¹⁵ atoms / cm ³ or more in the above range, carriers generated in the pre-exposure are light. The charge remaining in the conductive layer is canceled. Thereby, it is assumed that the pre-transfer charging ghost can be suppressed.

On the other hand, if the amount of pre-exposure light that reaches the photoconductive layer region where the atomic density of boron atoms is 9.64 × 10 ¹⁵ atoms / cm ³ or more is too large, the carrier generated by the pre-exposure is applied in the next main charging step. In some cases, a desired chargeability cannot be maintained because the generated charge may be erased. Conversely, if the amount of pre-exposure absorbed in the photoconductive layer region having an atomic density of boron atoms of 9.64 × 10 ¹⁵ atoms / cm ³ or more is too small, the desired ghost suppression effect may not be obtained.

Furthermore, in the image forming method of the present invention, in the electrophotographic photoreceptor in which a photoconductive layer composed of a-Si containing boron atoms and an a-SiC surface layer are sequentially formed on at least a substrate, the a-SiC The sum of the atomic densities of silicon atoms and carbon atoms in the surface layer is 6.60 × 10 ²² atoms / cm ³ or more, that is, the sum of the number of silicon atoms and carbon atoms per cm ³ is 6.60 ×. 10 ²² or more.

Since the a-SiC surface layer of the electrophotographic photoreceptor according to the present invention has a high atomic density (the sum of the atomic density of silicon atoms and the atomic density of carbon atoms is 6.60 × 10 ²² atoms / cm ³ or more), the film The interatomic distance between silicon atoms and carbon atoms forming the structure skeleton is shortened. Therefore, it is estimated that the bonding force between atoms forming the skeleton is improved. When an electrophotographic photoreceptor having such a surface layer laminated is used in an electrophotographic apparatus, it becomes possible to suppress the oxidation reaction of the surface layer due to a charging process using corona discharge or the like. Therefore, it is possible to suppress the formation of an oxide layer that functions as an antireflection layer on the outermost surface of the electrophotographic photosensitive member, and it is possible to suppress an increase in the amount of pre-exposure incident on the electrophotographic photosensitive member. As a result, it is possible to suppress an increase in the amount of pre-exposure light reaching the photoconductive layer region where the atomic density of boron atoms is 9.64 × 10 ¹⁵ atoms / cm ³ or more, and excessive carriers generated in the photoconductive layer Since the generation is suppressed, it is possible to suppress a decrease in charging ability. As a result, in the longitudinal direction of the electrophotographic photosensitive member, a decrease in image density due to partial formation of an oxide layer is suppressed.

Further, by suppressing the formation of the oxide layer on the surface of the electrophotographic photoreceptor, it is possible to suppress the formation of polar groups in the oxide layer at the same time. As a result, it is possible to suppress an increase in surface free energy of the electrophotographic photoreceptor, and thus it is possible to suppress the occurrence of surface adhesion to the electrophotographic photoreceptor. As a result, it is possible to reduce the increase in light reflectance on the surface of the electrophotographic photosensitive member during pre-exposure irradiation due to surface adhesion, and thus it is possible to suppress a decrease in the amount of pre-exposure light irradiated into the electrophotographic photosensitive member. It becomes. As a result, it is possible to suppress a decrease in the amount of pre-exposure light reaching the photoconductive layer region where the atomic density of boron atoms is 9.64 × 10 ¹⁵ atoms / cm ³ or more, and thus it is stably accumulated in the photoconductive layer. It is possible to erase the charges. As a result, it is possible to suppress the occurrence of a pre-transfer charging ghost due to partial surface adhesion in the longitudinal direction of the electrophotographic photoreceptor.

As described above, the amount of pre-exposure that reaches the photoconductive layer region where the atomic density of boron atoms is 9.64 × 10 ¹⁵ atoms / cm ³ or more is controlled while controlling the content distribution of boron atoms contained in the photoconductive layer. After setting the layer configuration to be in the above range, the surface layer is an a-SiC surface layer having a high atomic density, so that the ghost reduction effect can be maintained for a long time while maintaining good charging ability. It becomes possible.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

<Electrophotographic apparatus according to the present invention>
An electrophotographic forming method using an electrophotographic apparatus using an a-Si electrophotographic photoreceptor will be described with reference to FIG. First, the electrophotographic photoreceptor 1001 is rotated, and the surface of the electrophotographic photoreceptor is uniformly given a positive charge by the main charger 1002. Thereafter, the surface of the electrophotographic photoreceptor is exposed to light by the image exposure unit 1006 to form an electrostatic latent image on the surface of the electrophotographic photoreceptor, and then development is performed using the toner supplied from the developing unit 1012. As a result, a toner image is formed on the surface of the electrophotographic photoreceptor. Next, a pre-transfer charger 1013 is provided for supplying a charge to the toner forming the toner image on the electrophotographic photoreceptor 1001 so as to perform stable transfer. The polarity of the charge applied by the pre-transfer charger 1013 is opposite to the polarity of the charge applied to the electrophotographic photoreceptor 1001 by the main charger 1002, that is, has a negative polarity. That is, a negative charge is applied to the downstream side of the development process and the upstream side of the pre-exposure process. The toner image is transferred to a transfer material 1010 by a transfer charger 1004, and the transfer material 1010 is separated from the electrophotographic photoreceptor 1001 to fix the toner image on the transfer material.

  On the other hand, the toner remaining on the surface of the electrophotographic photoreceptor after the transfer of the toner image is removed by a cleaner 1009, and then the surface of the electrophotographic photoreceptor is exposed by the pre-exposure means 1003, whereby the static in the electrophotographic photoreceptor is exposed. The influence on the image by the remaining carrier during the electrostatic latent image is reduced. Image formation is continuously performed by repeating this series of processes.

In the present invention, pre-exposure in which the atomic density of boron atoms reaches a photoconductive layer region of 9.64 × 10 ¹⁵ atoms / cm ³ or more out of the pre-exposure light amount irradiated to the electrophotographic photoreceptor in the pre-exposure step. When the light quantity is A (μJ / cm ² ), Ln (A) obtained by returning A as a natural logarithm satisfies −12.0 or more and −4.5 or less.

  As described above, when Ln (A) is set to −12.0 or more, electrons accumulated in the photoconductive layer by the pre-transfer charging step can be sufficiently canceled by the carriers generated by the pre-exposure. . On the other hand, by setting Ln (A) to −4.5 or less, it is possible to suppress the influence on the charge applied in the next main charging step by the carrier generated by the pre-exposure. As a result, it is possible to reduce the pre-transfer charging ghost while maintaining the charging ability, and the effects of the present invention can be sufficiently obtained.

  For the reasons described above, by setting Ln (A) to be -12.0 or more and -4.5 or less, a great effect can be obtained in reducing the pre-transfer charging ghost while maintaining the charging ability. More preferably, by setting it to -11.0 or more and -6.0 or less, a great effect can be further obtained in reducing the pre-transfer charging ghost.

  Although different depending on the conditions of the electrophotographic process, examples of the step of applying a charge having a polarity opposite to the polarity applied in the main charging step include a pre-transfer charging step 1013, a transfer charging step 1004, and the like. In the present invention, the case where the pre-transfer charger 1013, which is an example of a step of applying a charge having a polarity opposite to the polarity applied in the main charging step, is described.

  The conditions for the current applied to the charger in the step of applying a charge having a polarity opposite to that applied in the main charging step include a DC current, an AC current, and a combination of a DC current and an AC current. There is no particular problem under the conditions used in a conventionally known electrophotographic apparatus having a body mounted thereon. For example, when a DC current is used, a current of about −10 μA to −600 μA may be applied to the charger.

  In the image forming method of the present invention, the wavelength of the pre-exposure is not particularly limited, but a wavelength (600 nm to 700 nm) used for a conventionally known electrophotographic apparatus equipped with an a-Si photosensitive member is used.

  The wavelength of image exposure is not particularly limited as long as the sensitivity capable of forming an electrostatic latent image is obtained, but the wavelength (from 630 nm) used in a conventionally known electrophotographic apparatus equipped with an a-Si photosensitive member. 750 nm) is used.

<Electrophotographic Photosensitive Member According to the Present Invention>
FIG. 2 is a schematic configuration diagram for explaining a layer configuration of an electrophotographic photoreceptor usable in the present invention.

FIG. 2 is a schematic diagram for explaining an electrophotographic photoreceptor according to the present invention, in which a charge injection blocking layer 2004, a photoconductive layer 2002, and a surface layer 2003 are sequentially laminated on a conductive substrate 2001. It is a photoreceptor. The photoconductive layer 2002 is made of a-Si containing hydrogen, and includes a photoconductive layer first region 2005 and a photoconductive layer second region 2006. Photoconductive layer first region 2005 is at the atom density of the boron atoms 9.64 × 10 ¹⁵ atoms / cm ³ or more, the photoconductive layer and the second region 2006 is atomic density of boron atoms 9.64 × 10 ¹⁵ atoms / Less than cm ³ .

  The layers shown in FIG. 2 are formed by appropriately setting the numerical conditions of the film forming parameters so as to obtain desired characteristics by a vacuum deposited film forming method. Specifically, it can be formed by a thin film deposition method such as a glow discharge method, a sputtering method, a vacuum deposition method, an ion plating method, a photo CVD method, or a thermal CVD method. Examples of the glow discharge method include an AC discharge CVD method such as a low frequency CVD method, a high frequency CVD method or a microwave CVD method, or a DC discharge CVD method.

  These thin film deposition methods are appropriately selected and employed depending on factors such as manufacturing conditions, the degree of load under capital investment, the manufacturing scale, and the characteristics desired for the produced photoreceptor. However, the glow discharge method, particularly the high-frequency glow discharge method using a power source frequency in the RF band, is preferable because the control of the conditions for manufacturing a photoreceptor having desired characteristics is relatively easy.

(Photoconductive layer)
In the present invention, the photoconductive layer is made of hydrogenated amorphous silicon, and the first photoconductive layer region in which the atomic density of boron atoms is 9.64 × 10 ¹⁵ atoms / cm ³ or more and the atomic density of boron atoms is 9.64. The photoconductive layer second region is smaller than × 10 ¹⁵ atoms / cm ³ .

  The reason why the photoconductive layer is formed in such two regions is that, as described above, a boron distribution capable of improving the traveling property of electrons and holes is formed, and ghosts are suppressed. Therefore, in the first region of the photoconductive layer and the second region of the photoconductive layer, the content distribution of boron atoms is adjusted so that the mobility of electrons and holes can be controlled.

  In the present invention, the photoconductive layer contains boron atoms, and the content thereof is the maximum concentration on the substrate side in the film thickness direction of the photoconductive layer, and is continuously linear or curved toward the surface side. It is characterized by a decreasing distribution.

  Thus, the amount of charges accumulated in the photoconductive layer is reduced by making the boron atom contained in the photoconductive layer a distribution that does not form the interface between the first photoconductive layer and the second photoconductive layer. It is possible to obtain a great effect on ghost reduction.

  In the present invention, the photoconductive layer can contain hydrogen atoms and / or halogen atoms to compensate for dangling bonds in a-Si.

  The total content of hydrogen atoms (H) and halogen atoms is preferably 10 atomic percent or more, more preferably 15 atomic percent or more, based on the sum of silicon atoms, hydrogen atoms, and halogen atoms. Moreover, it is preferable that it is 30 atomic% or less, and it is more preferable that it is 25 atomic% or less.

  In the present invention, the film thickness of the photoconductive layer (the total film thickness of the photoconductive layer first region and the photoconductive layer second region) is appropriately selected from the viewpoints of obtaining desired electrophotographic characteristics and economic effects. Determined by. Specifically, it is preferably 15 μm or more, and more preferably 20 μm or more. Further, it is preferably 60 μm or less, more preferably 50 μm or less, and particularly preferably 40 μm or less. By setting the film thickness of the photoconductive layer to 15 μm or more, it is possible to suppress an increase in the amount of passing current to the charging member and make it difficult to deteriorate. Further, by setting the film thickness of the photoconductive layer to 60 μm or less, it is possible to make it difficult to increase the abnormal growth site of a-Si.

  The photoconductive layer formed of a-Si can be formed by a known method such as a plasma CVD method, a vacuum deposition method, a sputtering method, or an ion plating method. It can be adopted as the most preferable method.

  Hereinafter, a method for forming a photoconductive layer will be described by taking a plasma CVD method as an example.

  In order to form the photoconductive layer, basically, a raw material gas for supplying silicon atoms and a raw material gas for supplying hydrogen atoms are introduced in a desired gas state into a reaction vessel capable of depressurizing the inside, and the reaction vessel Glow discharge is caused inside. Thus, the introduced source gas is decomposed, and a layer made of a-Si may be formed on a conductive substrate that is previously set at a predetermined position.

In the present invention, silanes such as silane (SiH ₄ ) and disilane (Si ₂ H ₆ ) can be suitably used as the source gas capable of supplying silicon atoms. In addition to the above silanes, hydrogen (H ₂ ) can also be suitably used as the source gas capable of supplying hydrogen atoms into the photoconductive layer.

  In addition, when an additive such as the above-mentioned halogen atom, boron atom, carbon atom, oxygen atom, nitrogen atom or the like is included, a gas containing each atom or a substance that can be easily gasified is appropriately used as a material. do it.

(Surface layer)
The present invention is characterized in that the sum of the atomic density of silicon atoms and the atomic density of carbon atoms in the surface layer of a-SiC (hydrogenated amorphous silicon carbide) is 6.60 × 10 ²² atoms / cm ³ or more.

By forming the sum of the atomic density of silicon atoms and the atomic density of carbon atoms in the a-SiC surface layer to be 6.60 × 10 ²² atoms / cm ³ or more, formation of an oxide layer on the surface of the electrophotographic photoreceptor and the surface It is possible to suppress adhesion. This reduces the change in the amount of pre-exposure incident on the electrophotographic photoreceptor, so that the atomic density of boron atoms in the longitudinal direction of the electrophotographic photoreceptor is 9.64 × 10 ¹⁵ atoms / cm ³ or more. It is possible to suppress a change in the amount of pre-exposure absorbed by the photoconductive layer region. As a result, it is possible to suppress a decrease in charging ability in the longitudinal direction of the electrophotographic photosensitive member due to changes such as formation of an oxide layer on the surface of the electrophotographic photosensitive member and occurrence of surface adhesion and generation of a pre-transfer charging ghost. It becomes possible. The reason why the change in the amount of pre-exposure incident on the electrophotographic photosensitive member can be suppressed will be described below.

  By increasing the atomic density of silicon atoms and carbon atoms constituting the a-SiC surface layer, it is difficult to break the bond between silicon atoms and carbon atoms, and the space ratio is reduced, so It is considered possible to reduce the reaction probability. This occurs because the oxidation reaction of a-SiC is caused by the bond between the silicon atom and the carbon atom being broken by the oxidation and desorption of the carbon atom, and the oxidizing substance reacts with the dangling bond of the newly generated silicon atom. Because. In the electrophotographic process, it is considered that oxidation and desorption of carbon atoms occur due to the reaction between ionic species generated in the charging step and carbon atoms. Therefore, it is considered that the oxidation of silicon atoms is suppressed by suppressing the oxidation of carbon atoms as much as possible. For that purpose, it is necessary to make the bond between the silicon atom and the carbon atom difficult to break, or to reduce the reaction probability in order to suppress the oxidation of the carbon atom. In order to realize this, it is considered necessary to shorten the distance between each atom and the space ratio.

Therefore, by increasing the atomic density of silicon atoms and carbon atoms constituting the a-SiC surface layer, it becomes possible to shorten the distance between each atom and to reduce the space ratio. Therefore, oxidation at the outermost surface of the a-SiC surface layer is possible. It is considered that formation of layers and generation of polar groups can be suppressed. As a result, it is possible to suppress the formation of an antireflection film on the surface of the electrophotographic photoreceptor, and to suppress surface adhesion. Therefore, it is speculated that the change in the amount of pre-exposure incident on the electrophotographic photoreceptor can be suppressed, and the decrease in charging ability and the occurrence of pre-transfer charging ghost in the longitudinal direction of the electrophotographic photoreceptor can be suppressed. The As a result, the effect of reducing the ghost by controlling the amount of pre-exposure to reach the photoconductive layer region where the atomic density of boron atoms is 9.64 × 10 ¹⁵ atoms / cm ³ or more can be maintained for a long time. It is possible to output a security image stably.

For these reasons, it is more preferable that the sum of the atomic density of silicon atoms and the atomic density of carbon atoms in the a-SiC surface layer is higher, and by making it 6.68 × 10 ²² atoms / cm ³ or more, A predetermined amount of pre-exposure light can stably enter the electrophotographic photoreceptor. The sum of the atomic density of silicon atoms and the atomic density of carbon atoms in the a-SiC surface layer is highest when it becomes a crystal. Therefore, as the upper limit of the sum of the atomic density of silicon atoms and the atomic density of carbon atoms in the present invention, the atomic density of SiC crystal (9.64 × 10 ²² atoms / cm ³ ) and the atomic density of diamond (17.65). X10 ²² atoms / cm ³ ) as a guide, and the upper limit is the atomic density at the time of crystallization calculated according to the ratio of the number of carbon atoms to the sum of the number of silicon atoms and the number of carbon atoms.

  Further, by setting the ratio of the number of carbon atoms to the sum of the number of silicon atoms and the number of carbon atoms in the a-SiC surface layer in a composition range of 0.61 to 0.75, further excellent electrons Photographic photoreceptor characteristics can be obtained.

  In the a-SiC surface layer, when the ratio of the number of carbon atoms to the sum of the number of silicon atoms and the number of carbon atoms is 0.61 or more, a-SiC having a high atomic density is produced. However, it is possible to suppress a decrease in the resistance of a-SiC. Thereby, it is possible to suppress the reduction of isolated dots due to the lateral flow of carriers in the surface layer when forming the electrostatic latent image. As a result, it is possible to produce an electrophotographic photoreceptor excellent in gradation in the output image, particularly on the low density side.

  Further, when the ratio of the number of carbon atoms to the sum of the number of silicon atoms and the number of carbon atoms is 0.75 or less, even when a-SiC having a high atomic density is produced, a-SiC Light absorption in the surface layer can be reduced. As a result, the amount of image exposure necessary for forming an electrostatic latent image is reduced, and an electrophotographic photoreceptor excellent in sensitivity characteristics can be produced.

  In the present invention, the ratio of the number of hydrogen atoms to the sum of the number of silicon atoms, the number of carbon atoms and the number of hydrogen atoms (hereinafter referred to as “H atom ratio”) is 0.30 or more. It is preferable to make it 0.45 or less. As a result, the electrophotographic photoreceptor characteristics are good, and the formation of an oxide layer and polar groups on the outermost surface of the electrophotographic photoreceptor can be suppressed.

  In an a-SiC surface layer having a high atomic density, the optical band gap is narrowed, and the light absorption increases, so that the sensitivity may decrease. However, when the H atomic ratio is 0.30 or more, the optical band gap is widened, and the sensitivity can be improved. Therefore, the H atomic ratio is preferably set to 0.30 or more.

  On the other hand, when the H atom ratio is larger than 0.45, there is a tendency that terminal groups with many hydrogen atoms such as methyl groups increase in the a-SiC surface layer. When a terminal group having a plurality of hydrogen atoms such as a methyl group is present in the a-SiC surface layer, a large space is formed in the structure of the a-SiC, and a bond between adjacent atoms is distorted. Let Such a structurally weak part is considered to be a very weak part against oxidation. Further, when a large amount of hydrogen atoms are contained in the a-SiC surface layer, it becomes difficult to promote the networking of silicon atoms and carbon atoms that are skeleton atoms in the a-SiC surface layer.

  For these reasons, by setting the H atomic ratio to 0.45 or less, the networking of silicon atoms and carbon atoms, which are skeleton atoms, in the a-SiC surface layer is promoted and the strain generated in the bonds between the atoms is reduced. It is thought that reduction is possible. As a result, the alteration of the a-SiC surface layer can be further suppressed.

  Therefore, in the a-SiC surface layer having a high atomic density, by setting the H atomic ratio to be 0.30 or more and 0.45 or less, the electrophotographic photoreceptor characteristics are further improved and the electrophotographic photoreceptor is most suitable. Generation of the surface oxide layer and polar groups can be further suppressed.

Further, the ratio of the peak intensity I _D of around 1390 cm ^-1 to the peak intensity I _G of around 1480 cm ^-1 in the Raman spectrum of the a-SiC surface layer, by 0.20 to 0.70, further electrophotographic A great effect can be obtained in suppressing the formation of the oxidized layer and polar groups on the outermost surface of the photosensitive member.

  First, the Raman spectrum of the a-SiC surface layer will be described in comparison with diamond-like carbon (hereinafter referred to as “DLC”).

Raman spectra of DLC formed of sp ³ structure and sp ² structure has a main peak near 1540 cm ^-1, asymmetrical Raman spectrum having a shoulder band is observed around 1390 cm ^-1. The RF-CVD method a-SiC surface layer made of, has a main peak near 1480 cm ^-1, the Raman spectrum similar to the DLC having a shoulder band around 1390 cm ^-1 is observed. The main peak of the a-SiC surface layer is shifted to the lower wavenumber side than DLC because the a-SiC surface layer contains silicon atoms. From this, it can be seen that the a-SiC surface layer produced by the RF-CVD method is a material having a structure very close to DLC.

In general, it is known that in the Raman spectrum of DLC, the smaller the ratio of the peak intensity of the low wave number band to the peak intensity of the high wave number band, the higher the sp ³ property of DLC. Therefore, since the a-SiC surface layer has a structure very close to that of DLC, it is considered that the smaller the ratio of the peak intensity of the low wavenumber band to the peak intensity of the high wavenumber band, the higher the sp ³ property. It is done.

In atomic dense a-SiC surface layer of the present invention, the ratio of the peak intensity I _D of around 1390 cm ^-1 to the peak intensity I _G of around 1480 cm ^-1 in the Raman spectrum by 0.70 or less, a- A great effect is obtained in suppressing the alteration of the SiC surface layer.

The reason for this is that when the sp ³ property is improved, the number of sp ² two-dimensional networks decreases and the number of sp ³ three-dimensional networks increases, so the number of skeletal atoms increases and a strong structure is formed. I think it is possible.

Therefore, the ratio of the peak intensity I _D of around 1390 cm ^-1 to the peak intensity I _G of around 1480 cm ^-1 in the Raman spectrum of the a-SiC surface layer is smaller is more preferable. However, the sp ² structure cannot be completely removed from the a-SiC surface layer produced at the mass production level. Therefore, in the present invention, the lower limit of the ratio of the peak intensity I _D of around 1390 cm ^-1 to the peak intensity I _G of around 1480 cm ^-1 in the Raman spectrum of the a-SiC surface layer, a-SiC surface layer in this embodiment 0.2, which was confirmed as a good range of oxidation and surface adhesion.

(Charge injection blocking layer)
In the electrophotographic photoreceptor of the present invention, it is effective to provide a charge injection blocking layer having a function of blocking charge injection from the substrate side between the substrate and the photoconductive layer. That is, the charge injection blocking layer has a function of blocking the injection of charges from the substrate to the photoconductive layer when the free surface of the electrophotographic photoreceptor is given a charge of a certain polarity. In order to provide such a function, the charge injection blocking layer contains a relatively large number of atoms for controlling conductivity as compared with the photoconductive layer.

  The atoms contained in the charge injection blocking layer for controlling conductivity may be contained in the charge injection blocking layer in a uniformly distributed state, or may be non-uniform in the film thickness direction. There may be a portion contained in a distributed state. If the distribution concentration is non-uniform, it is preferable to contain it so that it is distributed more on the substrate side. However, in any case, it is desirable that the atoms for controlling the conductivity are contained in a uniform distribution in the in-plane direction with respect to the substrate surface from the viewpoint of uniform characteristics.

  Group 13 atoms can be used as atoms to be included in the charge injection blocking layer in order to control conductivity.

  Furthermore, the charge injection blocking layer can contain at least one kind of carbon atom, nitrogen atom and oxygen atom to improve the adhesion between the charge injection blocking layer and the substrate. Become.

  A portion containing at least one of carbon atoms, nitrogen atoms and oxygen atoms contained in the charge injection blocking layer may be uniformly distributed in the layer or in a non-uniformly distributed state There may be. However, in any case, it is desirable to contain it in a uniform distribution in the direction parallel to the surface of the substrate from the viewpoint of uniform characteristics.

  The layer thickness of the charge injection blocking layer is preferably from 0.1 to 10 μm, more preferably from 0.3 to 5 μm, and even more preferably from the viewpoint of obtaining desired electrophotographic characteristics and economic effects. ˜3 μm. By setting the layer thickness to 0.1 μm or more, the charge injection ability from the substrate can be sufficiently obtained, and a preferable charging ability can be obtained. On the other hand, when the thickness is 10 μm or less, an increase in manufacturing cost due to an extension of the manufacturing time can be prevented.

(Substrate)
The substrate is not particularly limited as long as it has conductivity and can hold the photoconductive layer formed on the surface and the surface layer, and any substrate may be used. For example, metals such as Al, Cr, Mo, Au, In, Nb, Te, V, Ti, Pt, Pd, and Fe, or alloys thereof such as Al alloy and stainless steel can be used. In addition, a synthetic resin film such as polyester, polyethylene, polycarbonate, cellulose acetate, polypropylene, polyvinyl chloride, polystyrene, or polyamide, or an electrically insulating support such as sheet, glass, or ceramic can be used. In this case, the surface of the electrically insulating support on the side where the photoconductive layer is formed may be subjected to a conductive treatment.

<Manufacturing apparatus and manufacturing method for manufacturing electrophotographic photoreceptor according to the present invention>
FIG. 3 is a view schematically showing an example of a photoconductor deposition apparatus by RF plasma CVD using a high-frequency power source for producing an a-Si electrophotographic photoconductor according to the present invention.

  This apparatus is roughly divided into a deposition apparatus 3100 having a reaction vessel 3110, a source gas supply device 3200, and an exhaust device (not shown) for reducing the pressure inside the reaction vessel 3110.

  In a reaction vessel 3110 in the deposition apparatus 3100, a conductive substrate 3112, a conductive substrate heating heater 3113, and a source gas introduction pipe 3114 connected to the ground are installed. Further, a high frequency power source 3120 is connected to the cathode electrode 3111 via a high frequency matching box 3115.

The source gas supply device 3200 includes source gas cylinders 3221 to 3225 such as SiH ₄ , H ₂ , CH ₄ , NO, and B ₂ H ₆ , valves 3231 to 3235, pressure regulators 3261 to 3265, inflow valves 3241 to 3245, and outflow valves. 3251 to 3255 and mass flow controllers 3211 to 3215. A gas cylinder filled with each source gas is connected to a source gas introduction pipe 3114 in the reaction vessel 3110 via an auxiliary valve 3260.

  Next, a method for forming a deposited film using this apparatus will be described. First, a conductive substrate 3112 that has been degreased and washed in advance is placed in the reaction vessel 3110 via a cradle 3123. Next, an exhaust device (not shown) is operated to exhaust the reaction vessel 3110. While viewing the display of the vacuum gauge 3119, when the pressure in the reaction vessel 3110 reaches a predetermined pressure of, for example, 1 Pa or less, power is supplied to the substrate heating heater 3113, and the conductive substrate 3112 is moved to, for example, 50 ° C. to 350 ° C. To the desired temperature. At this time, an inert gas such as Ar or He can be supplied from the gas supply device 3200 to the reaction vessel 3110 and heated in an inert gas atmosphere.

  Next, a gas used to form a deposited film is supplied from the gas supply device 3200 to the reaction vessel 3110. That is, if necessary, the valves 3231 to 3235, the inflow valves 3241 to 3245, and the outflow valves 3251 to 3255 are opened, and the flow rate is set in the mass flow controllers 3211 to 3215. When the flow rate of each mass flow controller is stabilized, the main valve 3118 is operated while viewing the display of the vacuum gauge 3119 to adjust the pressure in the reaction vessel 3110 to a desired pressure. When a desired pressure is obtained, high-frequency power is applied from the high-frequency power source 3120 and simultaneously the high-frequency matching box 3115 is operated to generate plasma discharge in the reaction vessel 3110. Thereafter, the high frequency power is quickly adjusted to a desired power, and a deposited film is formed.

  When the formation of the predetermined deposited film is finished, the application of the high frequency power is stopped, the valves 3231 to 3235, the inflow valves 3241 to 3245, the outflow valves 3251 to 3255, and the auxiliary valve 3260 are closed, and the supply of the source gas is finished. At the same time, the main valve 3118 is fully opened, and the reaction vessel 3110 is evacuated to a pressure of 1 Pa or less.

  The formation of the deposited layers is completed as described above. When a plurality of deposited layers are formed, the above procedure is repeated again to form each layer. The bonding region can also be formed by changing the raw material gas flow rate, pressure, and the like to the conditions for forming the photoconductive layer in a certain time.

  After all the deposited films are formed, the main valve 3118 is closed, an inert gas is introduced into the reaction vessel 3110 to return to atmospheric pressure, and then the conductive substrate 3112 is taken out.

  The electrophotographic photoreceptor of the present invention has a film structure having a high atomic density by increasing the atomic density of silicon atoms and carbon atoms constituting a-SiC as compared to the surface layer of a conventionally known electrophotographic photoreceptor. The surface layer is formed. In order to produce an a-SiC surface layer having a high atomic density according to the present invention, it is generally better that the amount of gas supplied to the reaction vessel is small, and the high-frequency power is high, although it depends on the conditions during the formation of the surface layer. It is better, the pressure in the reaction vessel is better, and the temperature of the conductive substrate is better.

First, the gas decomposition can be promoted by reducing the amount of gas supplied into the reaction vessel and increasing the high-frequency power. Thereby, a carbon atom supply source (for example, CH ₄ ) that is harder to decompose than a silicon atom supply source (for example, SiH ₄ ) can be efficiently decomposed. As a result, active species having a small number of hydrogen atoms are generated, and the number of hydrogen atoms in the film deposited on the substrate is reduced, so that an a-SiC surface layer having a high atomic density can be formed.

Also, by increasing the pressure in the reaction vessel, the residence time of the raw material gas supplied into the reaction vessel is lengthened, and a weakly-bonded hydrogen abstraction reaction due to hydrogen atoms generated by the decomposition of the raw material gas occurs, We believe that the networking of silicon and carbon atoms will be promoted.
Furthermore, by raising the temperature of the conductive substrate, the surface movement distance of the active species that has reached the conductive substrate is increased, and a more stable bond can be created. As a result, it is considered that each atom can be bonded to a more structurally stable arrangement as the a-SiC surface layer.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further in detail, this invention is not restrict | limited at all by these.

(Photoconductive layer sample preparation method)
The conditions shown in Table 1 below on a glass substrate (Corning Corp., # 7059) having a width of 10 mm, a length of 38 mm, and a thickness of 1 mm using a plasma processing apparatus using a high frequency power source in the RF band as the frequency shown in FIG. A photoconductive layer sample was prepared by depositing only the photoconductive layer.

  As shown in FIG. 5, four glass substrates 5002 were installed at every 90 ° with respect to the arbitrary circumferential direction at the central position in the longitudinal direction in an arbitrary circumferential direction of a cylindrical substrate 5001 whose outer diameter was processed.

  About the photoconductive layer sample produced on the said conditions, the absorption coefficient of the photoconductive layer in wavelength 630nm was computed with the calculation method mentioned later. The results are shown in Table 3.

(Surface layer sample preparation method)
Similar to the photoconductive layer sample preparation method, the conditions shown in Table 2 below were applied on a glass substrate (# 7059, manufactured by Corning Inc.) having a width of 10 mm, a length of 38 mm, and a thickness of 1 mm using the plasma processing apparatus shown in FIG. A surface layer sample was prepared by depositing only the surface layer.

  As shown in FIG. 5, four glass substrates were installed every 90 ° at the center position in the longitudinal direction in an arbitrary circumferential direction of a cylindrical substrate whose outer diameter was processed.

  About the surface layer sample produced on the said conditions, the absorption coefficient of the surface layer in wavelength 630nm was computed with the calculation method similar to the photoconductive layer sample preparation method. The results are shown in Table 3.

(Absorption coefficient calculation method)
The absorption coefficient was calculated by determining the relationship between the wavelength and the transmittance of a sample prepared under each film forming condition using an ultraviolet-visible spectrophotometer (Nippon Denki Co., Ltd .: V-570 type). At this time, the glass substrate used at the time of sample preparation was used as a reference as a reference substrate.

  First, the transmittance T (%) at a wavelength of 630 nm was determined from the relationship between the obtained wavelength and the transmittance.

  Next, a sample prepared under each film forming condition is taken out from the ultraviolet-visible spectrophotometer, and a part of the deposited film is removed from the glass substrate using a cutter knife. Then, it is made to deposit on the sample produced on each film-forming condition from the level | step difference of the part which remove | eliminated the deposit film from the glass substrate, and the part which is not removed by the surface level | step difference meter (CLA-Tencor Corporation: ALPHA STEP 500). The film thickness D (cm) of the deposited film was measured.

Then, using the obtained T and D, the absorption coefficient α (1 / cm) was calculated by the following formula (3).
Formula (3) α = −1 / D × Ln (T / 100)

  The relationship between the wavelength and the transmittance measured by the spectrophotometer was measured using spectrum analysis of a spectrum manager (Nippon Denki Co., Ltd .: Rev. 1.00). The measurement conditions at this time are shown below. Measurement mode:% T. Response: Medium. Band width: 0.5 nm. Scanning speed: 1000 nm / min. Wavelength range: 300 nm to 1500 nm. Data acquisition interval: 2 nm.

  The film thickness was measured using a stylus diameter of 5 μm, and the measurement length and measurement speed were appropriately set according to the range in which the deposited film was removed with a cutter knife.

<Example 1>
Using a plasma processing apparatus using a high frequency power source in the RF band as the frequency shown in FIG. 3, the following is performed on a cylindrical substrate (cylindrical aluminum substrate having a diameter of 80 mm, a length of 358 mm, and a thickness of 3 mm). A positively charged a-Si electrophotographic photoreceptor was prepared under the conditions shown in Table 4. At that time, the charge injection blocking layer, the photoconductive layer first region, the photoconductive layer second region, and the surface layer are formed in this order, and the film thicknesses of the photoconductive layer second region and the surface layer are shown in Table 5. It was adjusted to become. Further, the total film thickness of the photoconductive layer first region and the photoconductive layer second region was adjusted to 28 μm.

Further, in the first region of the photoconductive layer, the B ₂ H ₆ flow rate relative to the SiH ₄ flow rate is 0.75 ppm at the position closest to the substrate side, and 0.20 ppm at the position closest to the second photoconductive layer region. _{The 2} H ₆ gas flow rate was continuously reduced in a straight line. Further, a straight line B ₂ H ₆ gas flow rate as B ₂ H ₆ flow rate to SiH ₄ flow rate at the interface position between the surface layer in the photoconductive layer and the second region is 0.00ppm from 0.20ppm to 0.00ppm Continuously reduced.

  For the electrophotographic photosensitive member of each film forming condition produced in Example 1, the charging ability and ghost are evaluated under the evaluation conditions described later, and the amount of pre-exposure reaching the first region of the photoconductive layer by the calculation method described later Ln (A) was calculated. The results are shown in Table 8.

  However, when evaluating the charging ability and ghost of the electrophotographic photosensitive member under each film forming condition prepared in Example 1, the surface of the electrophotographic photosensitive member is irradiated by an external power source connected to the pre-exposure LED. The pre-exposure light quantity I was performed under the conditions shown in Table 5.

In addition, when 0.20 ppm of the B ₂ H ₆ flow rate relative to the SiH ₄ flow rate is introduced at the time of forming the photoconductive layer first region, B contained in the photoconductive layer first region obtained by measurement of the B atom density described later is used. The atomic density was 9.64 × 10 ¹⁵ atoms / cm ³ .

In addition, for the electrophotographic photoreceptor surface layer of each film forming condition produced in Example 1, the ratio of the number of carbon atoms to the sum of the number of silicon atoms and the number of carbon atoms (hereinafter referred to as the following method) , C / (Si + C).) Was 6.81 × 10 ²² atoms / cm ³ .

<Comparative Example 1>
Similarly to Example 1, a positively charged a-Si electrophotographic photoreceptor was produced on a cylindrical substrate using a plasma processing apparatus using a high frequency power source in the RF band as shown in FIG. At that time, the charge injection blocking layer, the photoconductive layer first region, the photoconductive layer second region, and the surface layer are formed in this order under the conditions shown in Table 4 above, and the film thickness of the photoconductive layer second region and the surface layer is determined. Was adjusted to the film thickness shown in Table 6.

  In the same manner as in Example 1, the Ln (A,) charging ability and ghost were evaluated for the electrophotographic photoreceptors produced in Comparative Example 1 under various film forming conditions. The results are shown in Table 8.

  However, when evaluating the charging ability and ghost of the electrophotographic photosensitive member under each film forming condition prepared in Comparative Example 1, the surface of the electrophotographic photosensitive member is irradiated by an external power source connected to the pre-exposure LED. The pre-exposure light amount was measured under the conditions shown in Table 6.

<Comparative example 2>
Similar to Example 1, using a plasma processing apparatus using a high frequency power source in the RF band as shown in FIG. 3, a positive photoconductive layer having two photoconductive layers formed on a cylindrical substrate under the conditions shown in Table 7 was obtained. A charged a-Si based electrophotographic photoreceptor was produced.

  In the same manner as in Example 1, evaluation of Ln (A), charging ability, and ghost was performed on the electrophotographic photosensitive member of each film forming condition produced in Comparative Example 2. The results are shown in Table 8.

However, when evaluating the charging ability and ghost of the electrophotographic photosensitive member under each film forming condition prepared in Comparative Example 2, the surface of the electrophotographic photosensitive member is irradiated by an external power source connected to the pre-exposure LED. The pre-exposure light amount was 2.4 μJ / cm ² .

  The film forming condition No. of the electrophotographic photoreceptor produced in Comparative Example 2 was measured. Was set to 10.

(Chargeability evaluation)
As a method for evaluating the charging ability, a modified machine of a digital electrophotographic apparatus iR-5075 manufactured by Canon Inc. was used. In this electrophotographic apparatus, an external power source (not shown) is connected to a wire and grit of a main charger and a pre-exposed LED having a wavelength of 630 nm.

  This electrophotographic apparatus was installed in an environment at a temperature of 25 ° C. and a relative humidity of 50%, and the photoconductor heater was turned on. Further, the amount of light output from the pre-exposure LED was adjusted to a predetermined value by an external power source connected to the pre-exposure LED.

  After the produced electrophotographic photoreceptor is installed in the electrophotographic apparatus, a potential sensor is installed at a position corresponding to the center position in the longitudinal direction of the electrophotographic photoreceptor at the position of the developing device. Next, the pre-exposure is turned on under the above-mentioned conditions, and with the image exposure turned off, an external power supply is connected to the charger wire and grit, the grit potential is set to 820 V, and +750 μA is applied to the charger wire. The surface potential at the position of the developing device when applied was measured. Using this surface potential, the charging ability was evaluated. The evaluation results are shown in the film formation conditions No. 1 prepared in Example 1. 4 shows a relative comparison in which the surface potential when the electrophotographic photoreceptor No. 4 is mounted is 1.00.

  When the electrophotographic photosensitive member has a low charging ability, the surface potential decreases if the current applied to the wire of the main charger is constant. Accordingly, the higher the surface potential, the better the charging ability. In this evaluation, the larger the numerical value, the better the charging ability.

  Note that in an electrophotographic apparatus using an electrophotographic photosensitive member having a low charging capability, it may be difficult to increase the speed of the electrophotographic apparatus by increasing the process speed. For these reasons, it was determined that the effect of the present invention was obtained when the charging ability was evaluated as B or higher.

A ... Film formation conditions No. 1 prepared in Example 1 The ratio of the surface potential to the surface potential in the electrophotographic photoreceptor No. 4 is 0.96 or more.
B ... Film formation conditions No. 1 prepared in Example 1 The ratio of the surface potential to the surface potential of the electrophotographic photoreceptor No. 4 is 0.92 or more and less than 0.96.
C: Film formation condition No. 1 prepared in Example 1 The ratio of the surface potential to the surface potential in the electrophotographic photosensitive member 4 is less than 0.92.

(Ghost evaluation)
For the evaluation of the ghost, a modified machine of the digital electrophotographic apparatus iR-5075 manufactured by Canon Inc. was used. In this electrophotographic apparatus, an external power source (not shown) is connected to a wire and grit of a main charger and a pre-exposed LED having a wavelength of 630 nm.

  First, the amount of light output from the pre-exposure LED was adjusted to a predetermined amount by an external power source connected to the pre-exposure LED.

  Next, after the produced electrophotographic photoreceptor is installed in the above-described electrophotographic apparatus, a potential sensor is installed at a position corresponding to the center position in the longitudinal direction of the electrophotographic photoreceptor at the position of the developing device. Next, the pre-exposure is turned on under the above-mentioned conditions, the image exposure is turned off, the grid potential is set to 820 V, and the current supplied to the charger wire is adjusted to adjust the electrophotographic photosensitive member at the position of the developing device. The surface potential was set to + 400V. Next, image exposure was performed, and the potential at the developing unit position was set to 100 V by adjusting the irradiation energy. Thereafter, the potential sensor is taken out and a developing device is installed.

  For the evaluation of the ghost, using the test chart as shown in FIG. 6, the electrophotographic apparatus is installed in an environment of 22 ° C. and 50%, the photoconductor heater is turned on, and the surface of the electrophotographic photoconductor is approximately covered. The output was performed under the condition of keeping the temperature at 40 ° C. The test chart has a central position of the short side of the A3 chart on the left end side of the image, and a black square having a reflection density of 1.4 in a range of 40 mm □ centering on a position of 40 mm from the left end. A halftone (HT) having a reflection density of 0.4 is provided from a position 80 mm from the left end to a position 5 mm from the right end.

  Using the test chart, the left end side of the test chart was placed on the document table with the leading edge of the document, the developing bias was adjusted, and the reflection density of the HT portion of the test chart in the output image was set to 0.4. In this state, an A3 electrophotographic image was output, and the reflection density of the output image was measured.

  The measurement position is the center position of the short side of the A3 image, and the position of 291 mm from the left end of the A3 image (the position of one circle around the electrophotographic photoreceptor from the center of the black square) is the reference position, and the reference position and the comparison position There are a total of 5 points (4 points of A3 image short side direction ± 30 mm and long side direction ± 30 mm with respect to the reference position). Next, an average value Y of reflection densities measured at four comparison positions was obtained. The reflection density was measured using a reflection densitometer (X-Rite Inc: 504 spectral densitometer).

  Then, a difference (F−G) between the reflection density F at the reference position and the average value G of the reflection density at the comparison position was obtained, and the ghost was evaluated using this difference. The evaluation results are shown in the film formation conditions No. 1 prepared in Comparative Example 1. 9 shows a relative comparison in which the difference (F−G) between the reflection density F at the reference position and the reflection density average value G at the comparison position when the electrophotographic photoreceptor No. 9 is mounted is 1.00. .

  In this ghost evaluation, a combination of both a conventional ghost and a pre-transfer charging ghost is confirmed on the image. Therefore, a combination of a conventional ghost and a pre-transfer charging ghost is reflected in this ghost evaluation.

  When a ghost occurs, the reflection density F at the reference position is higher than the average value G of the reflection density at the comparison position. Therefore, in this evaluation, the smaller the numerical value, the better the ghost. In addition, it was judged that the effect of this invention was acquired by B or more with respect to evaluation of a ghost.

A: The value of the above (FG) is the same as the film formation condition No. 1 prepared in Comparative Example 1. Less than 0.80 for 9 electrophotographic photoreceptors.
B: The value of the above (FG) is the same as the film formation condition No. 1 prepared in Comparative Example 1. 9 is less than 0.90 and less than 0.95 with respect to 9 electrophotographic photoreceptors.
C: The value of the above (F−G) is the film forming condition No. 1 prepared in Comparative Example 1. 9 to less than 1.05 with respect to 9 electrophotographic photoreceptors.
D: The value of the above (FG) is the film formation condition No. 1 prepared in Comparative Example 1. 1.05 or more for 9 electrophotographic photoreceptors.

(Calculation method of Ln (A))
The calculation method of Ln (A) was as follows. The reflectance with respect to light having a wavelength of 630 nm on the outermost surface of the electrophotographic photoreceptor immediately after the production is 90 ° from the center position in the longitudinal direction of the electrophotographic photoreceptor in the arbitrary circumferential direction of the electrophotographic photoreceptor and the arbitrary circumferential direction. , 180 °, 270 ° rotated, a total of 4 points were measured. The average value a of the reflectance with respect to the obtained light having a wavelength of 630 nm was obtained, and this average value was taken as the reflectance of the electrophotographic photoreceptor produced under each film forming condition.

  The reflectance of the electrophotographic photoreceptor produced in Example 1 and Comparative Examples 1 and 2 was measured and found to be 10.8% ± 0.1. Therefore, a = 0.108 was used as the reflectance when calculating Ln (A).

Next, the absorption coefficient α1 of the surface layer shown in Table 3 and the absorption coefficient α2 of the photoconductive layer, the film thickness d1 (μm) of the surface layer shown in Table 5, Table 6, and Table 7, the film of the second region of the photoconductive layer Using the thickness d2 (μm), the pre-exposure light quantity I (μJ / cm ² ), and the reflectance a, the pre-exposure light quantity A reaching the photoconductive layer first region was calculated by the following equation (4). Finally, the calculated amount of pre-exposure A reaching the first region of the photoconductive layer was returned as a natural logarithm to calculate Ln (A).
Formula (4): A = exp (−α2 · d2 · 10 ⁻⁴ ) · exp (−α1 · d1 · 10 ⁻⁴ ) · I (1-a)
Although the photoconductive layer of an actual electrophotographic photoreceptor contains boron atoms, the absorption coefficient shown in Table 3 is used because the influence on the absorption coefficient is small.

(Measurement method of boron atom density)
A measurement sample is prepared by cutting out the central portion in the longitudinal direction in an arbitrary circumferential direction of the produced electrophotographic photosensitive member with 5 mm □. And the boron atom density in the depth direction of the electrophotographic photoreceptor was measured for the measurement sample by secondary ion mass spectrometry (Model 6650 manufactured by ULVAC-PHI).

In this measurement, oxygen ions are used as primary ion species, and B ⁺ is detected as secondary ions.

  After the measurement was completed, the sputter rate was calculated by measuring the depth of the portion sputtered by the primary ion irradiation, and the density was calculated based on the result.

  Further, a standard sample in which a fixed amount of boron was ion-implanted into a Si wafer was prepared, and the boron atom density was quantitatively calculated based on the result of measuring the standard sample in the same manner.

(Measurement method of hydrogen atom density)
The center part of the longitudinal direction in the arbitrary circumferential direction of the electrophotographic photoreceptor is cut out by 5 mm □ to prepare a sample, and the depth of the electrophotographic photoreceptor is measured by secondary ion mass spectrometry (Model 6650 manufactured by ULVAC-PHI). The hydrogen atom density in the direction was measured. In this measurement, cesium ions are used as primary ion species, and H ⁻ is detected as secondary ions.

  After the measurement was completed, the sputter rate was calculated by measuring the depth of the portion sputtered by the primary ion irradiation, and the density was calculated based on the result. Furthermore, a standard sample in which a fixed amount of hydrogen was ion-implanted into a Si wafer was prepared, and the hydrogen atom density was quantitatively calculated based on the result of measuring the standard sample by the same method.

  For Example 1 and Comparative Examples 1 and 2, the results relating to Ln (A), charging ability and ghost are shown in Table 8.

  From the results shown in Table 8, when the Ln (A) calculated from the pre-exposure light amount A reaching the first region of the photoconductive layer is set to −4.5 or less, the charging ability is improved and Ln (A) is set to −12. It has been found that the ghost is improved by setting it to 0.0 or more. Further, it was found that the charging ability is further improved by setting Ln (A) to −6.0 or less, and the ghost is further improved by setting Ln (A) to −11.0 or more.

  The reason why the ghost is improved by setting Ln (A) in the above-described range is presumed to be that the pre-transfer charging ghost is improved from the above-described conventional ghost and pre-transfer charging ghost mechanisms.

<Example 2>
Similarly to Example 1, a positively charged a-Si electrophotographic photoreceptor was produced on a cylindrical substrate using a plasma processing apparatus using a high frequency power source in the RF band as shown in FIG. At that time, the charge injection blocking layer, the photoconductive layer first region, the photoconductive layer second region, and the surface layer are formed in this order under the conditions shown in Table 9 below, and the film thickness of the photoconductive layer second region and the surface layer is determined. Was adjusted to the film thickness shown in Table 10. Further, the total film thickness of the photoconductive layer first region and the photoconductive layer second region was adjusted to 28 μm.

Further, in the first region of the photoconductive layer, the B ₂ H ₆ flow rate relative to the SiH ₄ flow rate is 0.90 ppm at the position closest to the substrate side, and 0.20 ppm at the position closest to the second photoconductive layer region. _{The 2} H ₆ gas flow rate was continuously reduced in a curve. Specifically, the position on the most substrate side of the first region of the photoconductive layer is 0 (μm), the distance (film thickness) from there to the surface side is D (μm), and the B ₂ H ₆ gas flow rate is y (ppm). The coefficients a and b were determined so as to satisfy the conditions of Table 9 from the following formula (5), and the B ₂ H ₆ gas flow rate y (ppm) was changed so as to satisfy the following formula (5).
Formula (5): y = a * exp (-b * D)

In the second region of the photoconductive layer, the flow rate of B ₂ H ₆ gas introduced into the photoconductive layer is 0.20 ppm so that the B ₂ H ₆ flow rate is 0.00 ppm relative to the SiH ₄ flow rate at the interface with the surface layer. Continuously decreased from 0.00 to 0.00 ppm in a curved line. Specifically, the position of the second region of the photoconductive layer closest to the substrate is 0 (μm), the distance (film thickness) from there to the surface side is D (μm), and the B ₂ H ₆ gas flow rate is y (ppm). The coefficients a and b were determined so as to satisfy the conditions of Table 9 from the following formula (6), and the B ₂ H ₆ gas flow rate y (ppm) was changed so as to satisfy the following formula (6).
Formula (6): y = a * exp (-b * D) -0.01

  The electrophotographic photosensitive member of each film forming condition produced in Example 2 was evaluated for charging ability and ghost by the same evaluation method as in Example 1, and the photoconductive layer was measured by the same calculation method as in Example 1. A pre-exposure light amount Ln (A) reaching one area was calculated. Even if a small amount of boron atoms is contained in the photoconductive layer, the effect on the absorption coefficient can be ignored. Therefore, the absorption coefficient of the photoconductive layer is the value shown in Table 3. The results are shown in Table 11.

  However, when evaluating the charging ability and ghost of the electrophotographic photoreceptor for each film forming condition prepared in Example 2, the surface of the electrophotographic photoreceptor is irradiated by an external power source connected to the pre-exposure LED. The pre-exposure light amount was measured under the conditions shown in Table 10.

In addition, when 0.20 ppm of the B ₂ H ₆ flow rate relative to the SiH ₄ flow rate is introduced at the time of forming the photoconductive layer first region, boron contained in the photoconductive layer first region obtained by measuring the boron atom density described above. The atomic density was 9.64 × 10 ¹⁵ atoms / cm ³ .

Regarding the amount of hydrogen contained in the photoconductive layer, the density of hydrogen atoms contained in the first region of the photoconductive layer obtained by the above-described measurement of the hydrogen atom density was 5.0 × 10 ²¹ atoms / cm ^3. It was.

  For Example 2, the results relating to Ln (A), charging ability and ghost are shown in Table 11.

From the results in Table 11, the amount of pre-exposure A reaching the first region of the photoconductive layer even when the flow rate of B ₂ H ₆ gas introduced into the photoconductive layer is continuously reduced so that boron atoms are contained in a curved shape. It was found that the charging ability was improved by setting the calculated Ln (A) to −4.5 or less.

  Furthermore, it was found that the ghost is improved by setting Ln (A) to -12.0 or more. Further, it was found that the charging ability is further improved by setting Ln (A) to −6.0 or less, and the ghost is further improved by setting Ln (A) to −11.0 or more.

<Example 3>
Similarly to Example 1, a positively charged a-Si electrophotographic photoreceptor was produced on a cylindrical substrate using a plasma processing apparatus using a high frequency power source in the RF band as shown in FIG. At that time, the charge injection blocking layer, the first photoconductive layer, the second photoconductive layer, and the surface layer are formed in this order under the conditions shown in Table 12 below, and the high-frequency power, SiH ₄ flow rate, and CH ₄ during the surface layer preparation are formed. The flow rate was prepared under the conditions shown in Table 13 below. The number of electrophotographic photoreceptors produced was 4 for each film forming condition.

However, in the first region of the photoconductive layer, the B ₂ H ₆ flow rate with respect to the SiH ₄ flow rate is 0.75 ppm at the position closest to the substrate side, and 0.20 ppm at the position closest to the photoconductive layer second region. The B ₂ H ₆ gas flow rate was continuously decreased linearly. Further, a straight line B ₂ H ₆ gas flow rate as B ₂ H ₆ flow rate to SiH ₄ flow rate at the interface position between the surface layer in the photoconductive layer and the second region is 0.00ppm from 0.20ppm to 0.00ppm Continuously reduced.

For the electrophotographic photosensitive member having four film formation conditions prepared in Example 3, the first electrophotographic photosensitive member for each film formation condition was used, and the atomic density of C / (Si + C) and silicon atoms (hereinafter referred to as “photosensitive members for silicon film”). , Referred to as “Si atom density”), the atomic density of carbon atoms (hereinafter referred to as “C atom density”), and the sum of the Si atom density and the C atom density (hereinafter referred to as “Si + C atom density”). ), The ratio of the number of hydrogen atoms to the sum of the number of silicon atoms, the number of carbon atoms and the number of hydrogen atoms (hereinafter referred to as “H atomic ratio”), the atomic density of hydrogen atoms (hereinafter referred to as “H”). (Referred to as “H atom density”) and sp ³ properties were determined by the analysis method described below. Then, using the second electrophotographic photoreceptor for each film formation condition, the oxidation resistance was evaluated under the evaluation conditions described later, and the evaluation method described later was performed using the third electrophotographic photoreceptor for each film formation condition. The surface adhesion was evaluated. Furthermore, using the fourth electrophotographic photoreceptor for each film formation condition, the gradation property and sensitivity were set to Ln (A) by the above-described calculation method, and the pre-exposure light amount was 2.4 μJ / cm ² by the evaluation method described later. Was evaluated. These results are shown in Table 16.

In addition, when 0.20 ppm of the B ₂ H ₆ flow rate with respect to the SiH ₄ flow rate is introduced at the time of forming the photoconductive layer first region, B contained in the photoconductive layer first region obtained by the measurement of the B atom density described above. The atomic density was 9.64 × 10 ¹⁵ atoms / cm ³ .

Regarding the amount of hydrogen contained in the photoconductive layer, the density of hydrogen atoms contained in the first region of the photoconductive layer obtained by the above-described measurement of the hydrogen atom density was 5.0 × 10 ²¹ atoms / cm ^3. It was.

The calculation of Ln (A) was performed as follows. First, as with the surface layer sample preparation method described above, a surface layer sample is prepared for the surface layer of each film formation condition prepared according to Example 3, and the absorption coefficient of each surface layer sample is calculated using the absorption coefficient calculation method described above. did. Next, Ln (A) was calculated | required with the calculation method of Ln (A) using the absorption coefficient of each surface layer sample. At this time, the absorption coefficient of the photoconductive layer was the value shown in Table 3, and the pre-exposure light quantity I was 2.4 μJ / cm ³ .

<Comparative Example 3>
As in Example 3, a positively charged a-Si electrophotographic photosensitive member is formed on a cylindrical substrate under the conditions shown in Table 12 above using a plasma processing apparatus using a high frequency power source in the RF band as shown in FIG. 4 were produced. However, the high frequency power, SiH ₄ flow rate, and CH ₄ flow rate at the time of surface layer preparation were set as the conditions shown in Table 14 below.

For the electrophotographic photoreceptor produced in Comparative Example 2, as in Example 3, C / (Si + C), Si atom density, C atom density, Si + C atom density, H atom ratio, H atom density, and sp ³ property were measured. The oxidation resistance, surface adhesion, Ln (A), gradation and sensitivity were evaluated. The results are shown in Table 16.

In addition, when 0.20 ppm of the B ₂ H ₆ flow rate with respect to the SiH ₄ flow rate is introduced at the time of forming the photoconductive layer first region, B contained in the photoconductive layer first region obtained by the measurement of the B atom density described above. The atomic density was 9.64 × 10 ¹⁵ atoms / cm ³ .

Regarding the amount of hydrogen contained in the photoconductive layer, the density of hydrogen atoms contained in the first region of the photoconductive layer obtained by the above-described measurement of the hydrogen atom density was 5.0 × 10 ²¹ atoms / cm ^3. It was.

<Comparative example 4>
Four positively charged a-Si electrophotographic photoreceptors were produced on a cylindrical substrate under the conditions shown in Table 15 below using a plasma processing apparatus using a high frequency power source in the RF band as the frequency shown in FIG.

For the electrophotographic photoreceptor produced in Comparative Example 4, as in Example 3, C / (Si + C), Si atom density, C atom density, Si + C atom density, H atom ratio, H atom density, and sp ³ property were measured. The oxidation resistance, surface adhesion, Ln (A), gradation and sensitivity were evaluated. The results are shown in Table 16. The film forming condition No. of the electrophotographic photoreceptor produced in Comparative Example 3 was measured. Was set to 22.

In addition, when 0.20 ppm of the B ₂ H ₆ flow rate with respect to the SiH ₄ flow rate is introduced at the time of forming the photoconductive layer first region, B contained in the photoconductive layer first region obtained by the measurement of the B atom density described above. The atomic density was 9.64 × 10 ¹⁵ atoms / cm ³ .

Regarding the amount of hydrogen contained in the photoconductive layer, the density of hydrogen atoms contained in the first region of the photoconductive layer obtained by the above-described measurement of the hydrogen atom density was 5.0 × 10 ²¹ atoms / cm ^3. The

(Measurement of C / (Si + C), Si atom density, C atom density, Si + C atom density, H atom ratio)
First, a reference electrophotographic photosensitive member in which only the charge injection blocking layer, the photoconductive layer first region, and the photoconductive layer second region of Table 12 are laminated is prepared, and the central portion in the longitudinal direction in any circumferential direction is 15 mm. A reference sample was prepared by cutting out with □. Next, the electrophotographic photosensitive member in which the charge injection blocking layer, the photoconductive layer first region, the photoconductive layer second region, and the surface layer were laminated was similarly cut out to prepare a measurement sample. The reference sample and the measurement sample were measured by spectroscopic ellipsometry (manufactured by JA Woollam: high-speed spectroscopic ellipsometry M-2000) to determine the film thickness of the surface layer.

  Specific measurement conditions of spectroscopic ellipsometry are incident angles: 60 °, 65 °, 70 °, measurement wavelengths: 195 nm to 700 nm, and beam diameter: 1 mm × 2 mm.

  First, the relationship between the wavelength, the amplitude ratio Ψ, and the phase difference Δ was determined for each reference angle of the reference sample by spectroscopic ellipsometry.

  Next, using the measurement result of the reference sample as a reference, the relationship between the wavelength, the amplitude ratio Ψ, and the phase difference Δ was determined at each incident angle by spectroscopic ellipsometry, similarly to the reference sample.

  Further, a layer structure having a charge injection blocking layer, a photoconductive layer first region, a photoconductive layer second region, and a surface layer sequentially laminated, and a rough layer in which the surface layer and the air layer coexist on the outermost surface is used as a calculation model. Using the analysis software, the relationship between the wavelength at each incident angle and Ψ and Δ was calculated. Then, select the calculation model when the mean square error of the relationship between the wavelength, Ψ, and Δ obtained by the above calculation at each incident angle and the relationship between the wavelength, Ψ, and Δ obtained by measuring the measurement sample is minimized. did. The film thickness of the surface layer was calculated using the selected calculation model, and the obtained value was taken as the film thickness of the surface layer. The analysis software is J.I. A. Woolase WVASE32 was used. The volume ratio of the surface layer to the air layer in the roughness layer was calculated by changing the ratio of the air layer in the roughness layer by 1 from 10: 0 to 1: 9 in the surface layer: air layer. In the positively charged a-Si photosensitive member produced according to each film forming condition in this example, the wavelength, ψ, and the wavelength obtained by calculation when the volume ratio of the surface layer of the roughness layer to the air layer is 8: 2. The mean square error of the relationship between Δ and the wavelength obtained by measurement and the relationship between Ψ and Δ was minimized.

  After the measurement by spectroscopic ellipsometry is completed, the sample for measurement is measured in the surface layer in the RBS measurement area by RBS (Rutherford backscattering method) (manufactured by Nissin High Voltage Co., Ltd .: backscattering measuring device AN-2500). The number of silicon atoms and carbon atoms was measured. From the measured number of silicon atoms and carbon atoms, C / (Si + C) was determined. Next, Si atom density, C atom density, and Si + C atom density were determined using the surface layer thickness determined by spectroscopic ellipsometry for silicon atoms and carbon atoms determined from the RBS measurement area.

  Simultaneously with the RBS, the number of hydrogen atoms in the surface layer in the HFS measurement area was measured using the HFS (hydrogen forward scattering method) (manufactured by Nisshin High Voltage Co., Ltd .: backscattering measurement device AN-2500). Was measured. The H atom ratio was determined from the number of hydrogen atoms determined from the HFS measurement area and the number of silicon atoms and carbon atoms determined from the RBS measurement area. Next, the H atom density was determined using the thickness of the surface layer determined by spectroscopic ellipsometry with respect to the number of hydrogen atoms determined from the HFS measurement area.

Specific measurement conditions for RBS and HFS are incident ion: 4He ⁺ , incident energy: 2.3 MeV, incident angle: 75 °, sample current: 35 nA, incident beam length: 1 mm, and the detector of RBS is scattered. Angle: 160 °, aperture diameter: 8 mm, HFS detector measured at recoil angle: 30 °, aperture diameter: 8 mm + Slit.

(Oxidation resistance evaluation)
The oxidation resistance evaluation is a method for evaluating the formation of an oxide layer formed on the outermost surface of the a-SiC surface layer.

  The reflectivity for light having a wavelength of 630 nm on the outermost surface of the electrophotographic photoreceptor immediately after the production is 9 points in the longitudinal direction in any circumferential direction of the electrophotographic photoreceptor (based on the center in the longitudinal direction of the electrophotographic photoreceptor) 0 mm, ± 50 mm, ± 90 mm, ± 130 mm, ± 150 mm) and 9 points in the longitudinal direction at a position rotated by 180 ° from the arbitrary circumferential direction, a total of 18 points were measured.

  The measuring method irradiates light perpendicularly on the surface of the electrophotographic photosensitive member with a spot diameter of 2 mm, and performs spectroscopic measurement of reflected light using a spectrometer (manufactured by Otsuka Electronics: MCPD-2000).

  After the measurement, the produced electrophotographic photoreceptor is installed in a modified machine of a digital electrophotographic apparatus iR-5075 manufactured by Canon Inc. installed in a high temperature and high humidity environment at a temperature of 30 ° C. and a relative humidity of 80%.

  In this electrophotographic apparatus, an external power supply (not shown) is connected to the wire and grit of the main charger, and the developer, pre-transfer charger, transfer charger, separation charger and cleaner are removed, and the paper is transported. It has been modified so that it will not be.

  After the produced electrophotographic photoreceptor is installed in the modified electrophotographic apparatus described above, a potential sensor is installed at a position corresponding to the center position in the longitudinal direction of the electrophotographic photoreceptor at the position of the developing device. Next, the pre-exposure was turned on, the grit potential was adjusted to 820 V, and the potential sensor at the developing unit position was adjusted to +600 V by an external power source (not shown) connected to the wire of the main charger. After adjustment, turn off the external power supply and remove the potential sensor. Then, the pre-exposure is turned on again, the grit potential is set to 820 V, a current at which the potential at the developing unit is +600 V is applied to the wire of the main charger by an external power source, and the photoconductor heater is turned off for 50 hours. The electrophotographic photoreceptor is continuously rotated.

  After 50 hours, the electrophotographic photoreceptor is taken out of the electrophotographic apparatus, and the reflectance with respect to light having a wavelength of 630 nm is measured at the same place as immediately after the electrophotographic photoreceptor is produced.

  Next, the ratio of the reflectance measured after 50 hours to the reflectance measured immediately after production at each measurement position was determined, and oxidation resistance was evaluated using an average value of 18 points.

  When an oxide layer is formed on the outermost surface of the electrophotographic photoreceptor, the reflectance decreases. Therefore, the oxidation resistance becomes better as the ratio of the reflectance with respect to the light with a wavelength of 630 nm measured after 50 hours with respect to the reflectance with respect to the light with a wavelength of 630 nm measured immediately after the production is closer to 100%. In addition, it was judged that the effect of this invention was acquired by D or more with respect to oxidation resistance evaluation.

A: The ratio of the reflectance with respect to the light with a wavelength of 630 nm measured after 50 hours to the reflectance with respect to the light with a wavelength of 630 nm measured immediately after the production is 95% to 105%.
B: The ratio of the reflectance with respect to the light with a wavelength of 630 nm measured after 50 hours with respect to the reflectance with respect to the light with a wavelength of 630 nm measured immediately after the production is 90% or more and less than 95%.
C: The ratio of the reflectivity for light with a wavelength of 630 nm measured after 50 hours to the reflectivity for light with a wavelength of 630 nm measured immediately after fabrication is 85% or more and less than 90%.
D: The ratio of the reflectance with respect to the light with a wavelength of 630 nm measured after 50 hours with respect to the reflectance with respect to the light with a wavelength of 630 nm measured immediately after the production is 80% or more and less than 85%.
E: The ratio of the reflectance to light having a wavelength of 630 nm measured after 50 hours with respect to the reflectance to light having a wavelength of 630 nm measured immediately after fabrication is 75% or more and less than 80%.
F: The ratio of the reflectance with respect to the light with a wavelength of 630 nm measured after 50 hours with respect to the reflectance with respect to the light with a wavelength of 630 nm measured immediately after the production is less than 75%.

(Surface adhesion evaluation)
For the evaluation of surface adhesion, a modified machine of the digital electrophotographic apparatus iR-5075 manufactured by Canon Inc. was used. In this electrophotographic apparatus, an LED (wavelength: 630 nm) similar to that in the pre-exposure is installed at the image exposure position, and the main charger wire, grit, pre-exposure LED, and the LED at the position of the image exposure means are not shown externally. The power supply is connected. Further, the amount of light output from the pre-exposure LED was adjusted to a predetermined value by an external power source connected to the pre-exposure LED.

  After the electrophotographic photoreceptor immediately after fabrication is installed in the above-described modified electrophotographic apparatus, a potential sensor is installed at a position corresponding to the center position of the electrophotographic photoreceptor in the longitudinal direction at the position of the developing device. Next, the pre-exposure is turned on, the LED installed at the image exposure position is turned off, the grid potential is set to 820 V, the current supplied to the charger wire is adjusted, and the electrophotographic photosensitive member at the developer position is adjusted. The body surface potential was set to 600V.

  Next, the LED installed at the image exposure position is irradiated in the state of being charged under the previously set charging conditions, and the irradiation energy is adjusted to set the potential at the developing unit position to 100 V, and the irradiation energy at that time Was defined as the irradiation energy before the continuous paper passing durability test.

  Next, a continuous sheet-passing durability tester is prepared using an electrophotographic apparatus having a configuration shown in FIG. 1 (a digital electrophotographic apparatus iR-5075 manufactured by Canon Inc.).

  This continuous sheet-passing durability tester is an electrophotographic apparatus modified so that the contact pressure between the electrophotographic photoreceptor 1001 and the cleaning blade 1008 can be changed.

Then, by using the measuring device shown in FIG. 4, the adjustment screw 1016 for fixing the cleaning blade holding member 1014 and the fixing member 10 ¹⁵ is used to contact the electrophotographic photosensitive member of the continuous sheet-passing durability tester with the cleaning blade. Set the pressure.

  The configuration of the measuring apparatus 4000 shown in FIG. 4 will be described below. The measuring device 4000 has a structure in which a support base 4005 is assembled to flanges 4002 and 4003. Bearings 4001 and 4004 are attached to the flanges 4002 and 4003, and the bearings 4001 and 4004 are rotatably attached to the electrophotographic apparatus in the same manner as the electrophotographic photoreceptor unit. A load cell 4007 (manufactured by TEAC Corporation: TC-PAR 200N) is attached to the support base 4005 at a position corresponding to the center in the axial direction of the electrophotographic photoreceptor. In addition, load cells 4006 and 4008 are attached at positions 130 mm apart from each other about the load cell 4007. Each load cell is connected to a display (TEAC Co., Ltd .: TD-240A, not shown), and the load applied to the load buttons 4009 to 4011 located at the centers of the load cells 4006 to 4008 can be read.

  Further, a pressure receiving plate 4012 in which an aluminum plate having a width of 30 mm, a length of 300 mm, and a thickness of 3 mm and having a mirror-finished surface is curved with a radius of 40 mm is installed at the tip of the load buttons 4009 to 4011. The pressure receiving plate 4012 mechanically connects the load buttons. The pressure plate is installed so that the center of curvature of the pressure plate coincides with the center axis of the flange, and the surface is 40 mm from the center axis of the flange.

  This measuring apparatus was installed in the above-mentioned continuous paper passing durability tester instead of the electrophotographic photoreceptor, and was adjusted so that the sum of the pressure applied to the three load cells was 150 g ± 5 g. However, the pressure applied to each load cell was adjusted so that the difference between the maximum value and the minimum value was 10 g or less.

  Then, after removing the measuring device and installing the electrophotographic photoreceptor removed from the modified electrophotographic apparatus in the continuous paper passing durability tester, the temperature is 30 ° C. and the relative humidity is 80% in a high temperature and high humidity environment. Then, a continuous paper passing durability test was conducted under the condition that the photoconductor heater was turned on.

  During the continuous paper endurance test, the photoconductor heater is always turned on while the continuous paper endurance tester is in operation and the continuous paper endurance test is being performed and while the continuous paper endurance tester is stopped. It carried out on the conditions to.

  Specifically, a continuous sheet-passing durability test of 25,000 sheets per day is performed up to 100,000 sheets using an A4 test pattern with a printing rate of 1%. The toner used for the surface adhesion evaluation was a toner prepared under the following conditions. After conducting a continuous sheet-passing durability test for 100,000 sheets, the electrophotographic photosensitive member was taken out from the continuous sheet-passing durability tester.

  After the continuous paper endurance test was completed, the electrophotographic photoreceptor was installed in the modified electrophotographic apparatus, and the irradiation energy after the continuous paper endurance test was measured in the same manner as before the continuous paper endurance test. .

  From this measured value, an irradiation energy ratio before and after the continuous paper passing durability test (irradiation energy after the continuous paper passing durability test / irradiation energy before the continuous paper passing durability test) was obtained and used to evaluate surface adhesion. However, the evaluation results are the film formation conditions No. 1 prepared in Comparative Example 4. Relative comparison was performed with the irradiation energy ratio of 22 electrophotographic photoreceptors before and after the continuous paper passing durability test being 1.00.

  When surface adhesion occurs on the outermost surface of the electrophotographic photosensitive member, the irradiation energy after the continuous paper passing durability test increases with respect to the irradiation energy before the continuous paper passing durability test. Therefore, in this evaluation, it is shown that the smaller the numerical value, the better the surface adhesion, and the less the increase in irradiation energy before and after the continuous paper passing durability test. In addition, it was judged that the effect of this invention was acquired by D or more with respect to evaluation of surface adhesion.

A. The irradiation energy ratio before and after the continuous paper passing durability test is the same as the film formation condition No. 1 prepared in Comparative Example 4. Less than 0.95 with respect to the irradiation energy ratio of 22 electrophotographic photoreceptors before and after the continuous paper passing durability test.
B. The irradiation energy ratio before and after the continuous paper endurance test is the same as the film formation condition No. 1 prepared in Comparative Example 4. The irradiation energy ratio of the 22 electrophotographic photoreceptors before and after the continuous paper passing durability test was 0.96 or more and less than 0.97.
C: The irradiation energy ratio before and after the continuous paper endurance test is the same as the film formation condition No. 1 prepared in Comparative Example 4. The irradiation energy ratio of 22 electrophotographic photoreceptors before and after the continuous paper passing durability test was 0.97 or more and less than 0.98.
D: The irradiation energy ratio before and after the continuous paper endurance test is the same as the film formation condition No. 1 prepared in Comparative Example 4. The irradiation energy ratio of 22 electrophotographic photoreceptors before and after the continuous paper passing durability test was 0.98 or more and less than 0.99.
E. The irradiation energy ratio before and after the continuous paper endurance test is the same as the film formation condition No. 22 or more and less than 1.00 with respect to the irradiation energy ratio before and after the continuous sheet-passing durability test on 22 electrophotographic photoreceptors.
F: The irradiation energy ratio before and after the continuous paper endurance test is the same as the film formation condition No. 22 or more with respect to the irradiation energy ratio before and after the continuous paper passing durability test on the electrophotographic photoreceptor of 22.

<Production example of toner for surface adhesion evaluation>
First, a binder resin was produced under the following conditions.
Propoxylated bisphenol A (2.2 mol added): 25.0 mol%
Ethoxylated bisphenol A (2.2 mol added): 25.0 mol%
・ Terephthalic acid: 37.2 mol%
-Trimellitic anhydride: 12.8 mol%

Charge the above-mentioned monomer and esterification solvent into a 5 liter autoclave, attach a reflux condenser, moisture separator, N ₂ gas inlet tube, thermometer and stirrer, and introduce the N ₂ gas into the autoclave at 230 ° C. The polycondensation reaction was carried out. After completion of the reaction, it was taken out from the container, cooled and pulverized to produce a binder resin.

Next, an example of manufacturing a toner for surface adhesion evaluation will be shown. In addition, the number of parts shown below is a mass part.
Binder resin: 100 parts Magnetic iron oxide particles (average particle size 0.15 μm, Hc = 11.5 kA / m, σs = 88 Am2 / kg, σr = 14 Am2 / kg): 70 parts Fischer-Tropsch wax (melting point: 101 ° C.): 4 parts Charge control agent (structural formula is described later): 2 parts

  The above materials were premixed with a Henschel mixer and then melt kneaded with a twin-screw kneading extruder.

The prepared kneaded product is cooled, coarsely pulverized with a hammer mill, then pulverized with a turbo mill, and the resulting finely pulverized powder is classified using a multi-division classifier utilizing the Coanda effect to obtain a weight average particle size of 5 A negatively chargeable magnetic toner of 9 μm was prepared. Hydrophobic silica fine powder [BET specific surface area 150 m ² / g, hydrophobized with 30 parts hexamethyldisilazane (HMDS) and 10 parts dimethyl silicone oil to 100 parts silica fine powder] 1.0 part of inorganic fine powder, 0.2 part of titanium oxide fine powder (D50: 0.3 μm), and 3.0 part of strontium titanate fine powder (D50: 1.0 μm) were externally added and mixed. A toner for evaluation of toner fusion was prepared by sieving with a mesh having an opening of 150 μm.

  The structure of the charge control agent is shown below.

(Gradation evaluation)
For the evaluation of gradation, a modified machine of a digital electrophotographic apparatus iR-5075 manufactured by Canon Inc. was used. First, all gradations are obtained by area gradation (that is, area gradation of a dot portion where image exposure is performed) using an area gradation dot screen at a line density of 45 degrees 170 lpi (170 lines per inch) by image exposure light. Gradation data was created with the range evenly distributed in 17 steps. At this time, the darkest gradation is set to 16, the thinnest gradation is set to 0, and a number is assigned to each gradation to make a gradation step.

  Next, an electrophotographic photosensitive member is installed in the above-described modified electrophotographic apparatus, and output to A3 paper using the text mode using the above-described gradation data. At this time, if a high-humidity flow is generated, the evaluation of gradation is affected. Therefore, in an environment of 22 ° C. and 50%, the photoconductor heater is turned on to keep the surface of the electrophotographic photoconductor at about 40 ° C. Was output under different conditions.

  The image density of the obtained image was measured with a reflection densitometer (manufactured by X-Rite Inc: 504 spectral densitometer) for each gradation. In the reflection density measurement, three images were output for each gradation, and the average value of the densities was used as the evaluation value.

  The correlation coefficient between the evaluation value obtained in this way and the gradation stage is calculated, and from the correlation coefficient = 1.00 when the gradation expression in which the reflection density of each gradation changes completely linearly is obtained. The difference of was calculated. And film-forming conditions No. The correlation coefficient and correlation coefficient 1.00 of the electrophotographic photoreceptor produced under each film forming condition with respect to the difference between the correlation coefficient of the electrophotographic photoreceptor produced in 18 and the correlation coefficient 1.00 The difference ratio was evaluated as an index of gradation. In this evaluation, the smaller the numerical value, the better the gradation, indicating that the gradation expression is linear.

A ... Film formation condition No. The correlation coefficient and correlation coefficient of the electrophotographic photosensitive member produced under each film forming condition with respect to the difference between the correlation coefficient of the electrophotographic photosensitive member produced in Step 18 and the correlation coefficient = 1.00 = 1. Ratio of difference with 00 is 1.80 or less.
B ... Film formation condition No. The correlation coefficient and correlation coefficient of the electrophotographic photosensitive member produced under each film forming condition with respect to the difference between the correlation coefficient of the electrophotographic photosensitive member produced in Step 18 and the correlation coefficient = 1.00 = 1. The ratio of the difference from 00 is greater than 1.80 and less than or equal to 2.20.
C: Film formation condition No. The correlation coefficient and correlation coefficient of the electrophotographic photosensitive member produced under each film forming condition with respect to the difference between the correlation coefficient of the electrophotographic photosensitive member produced in Step 18 and the correlation coefficient = 1.00 = 1. The ratio of the difference from 00 is greater than 2.20.

(Sensitivity evaluation)
A modified machine of a digital electrophotographic apparatus iR-5075 manufactured by Canon Inc. was used. In this electrophotographic apparatus, an external power source (not shown) is connected to wires, grit and pre-exposure LEDs of a main charger. Further, the amount of light output from the pre-exposure LED was adjusted to a predetermined value by an external power source connected to the pre-exposure LED.

  After the electrophotographic photoreceptor produced in this electrophotographic apparatus is installed, a potential sensor is installed at a position corresponding to the center position in the longitudinal direction of the electrophotographic photoreceptor at the position of the developing device. Next, the pre-exposure is turned on, the image exposure is turned off, the grid potential is set to 820 V, the current supplied to the wire of the charger is adjusted, and the surface potential of the electrophotographic photoreceptor at the position of the developer is set to 400 V. Was set to be.

  Next, image exposure was performed in a state of being charged under the previously set charging condition, and the potential at the developing unit was set to 100 V by adjusting the irradiation energy.

  A modified machine of a digital electrophotographic apparatus iR-5075 manufactured by Canon Inc. was used. With the image exposure turned off, an external power source is connected to the charger wire and grit, the grit potential is set to 820 V, and the current supplied to the charger wire is adjusted to adjust the electrophotographic photosensitive member at the position of the developer. The surface potential was set to 400V.

  The image exposure light source of the electrophotographic apparatus used for sensitivity evaluation is a semiconductor laser having an oscillation wavelength of 658 nm. The evaluation result is the film formation condition No. 1 prepared in Comparative Example 4. Relative comparison was performed with an irradiation energy of 1.00 when 22 electrophotographic photoreceptors were mounted.

A: Film formation conditions No. 1 prepared in Comparative Example 4 The ratio of the irradiation energy to the irradiation energy in 22 electrophotographic photoreceptors is less than 1.10.
B: Film formation condition No. 1 prepared in Comparative Example 4 The ratio of the irradiation energy to the irradiation energy in the produced electrophotographic photoreceptor of No. 22 is 1.10 or more and less than 1.15.
C: Film formation condition No. 1 prepared in Comparative Example 4 The ratio of the irradiation energy to the irradiation energy of 22 electrophotographic photoreceptors is 1.15 or more and less than 1.20.
D ... Film formation conditions No. 1 prepared in Comparative Example 4 The ratio of the irradiation energy to the irradiation energy of the electrophotographic photosensitive member 22 is 1.20 or more.

(Sp ³ sex evaluation)
The sp3 property was calculated with a laser Raman spectrophotometer (manufactured by JASCO Corporation: NRS-2000) from a sample obtained by cutting out the central portion in the longitudinal direction of the electrophotographic photoreceptor in an arbitrary circumferential direction with 10 mm □.

Specific measurement conditions were as follows: light source: Ar ⁺ laser 514.5 nm, laser intensity: 20 mA, objective lens: 50 times, center wavelength 1390 cm ⁻¹ , exposure time 30 seconds, total 5 times. The analysis method of the obtained Raman spectrum is shown below. The peak wavenumber of a shoulder Raman band was fixed at 1390 cm ^-1, the peak wavenumber of a main Raman band without fixation is set to 1480 cm ^-1, were curve fitting using a Gaussian distribution. At this time, the baseline was linear approximation. I _D / I _G was calculated from the peak intensity I _G of the main Raman band and the peak intensity I _D of the shoulder Raman band obtained by curve fitting, and the average of three times was used for evaluation of the sp ³ property.

For Example 3 and Comparative Examples 3 and 4, C / (Si + C), Si atom density, C atom density, Si + C atom density, H atom ratio, H atom density and sp ³ property in the surface layer, and oxidation resistance, surface Table 16 shows the results regarding adhesion, Ln (A), gradation, and sensitivity.

From the results of Table 16, it was found that the oxidation resistance and surface adhesion are improved by setting the Si + C atom density of the surface layer to 6.60 × 10 ²² atoms / cm ³ or more. It was also found that the oxidation resistance and surface adhesion were further improved by setting the Si + C atom density to 6.81 × 10 ²² atoms / cm ³ or more.

  From this result, by setting the Si + C atom density of the surface layer within the above range, a change in the outermost surface of the a-SiC surface layer is suppressed, and the stability of the pre-exposure light amount incident on the electrophotographic photoreceptor is excellent. It was found that a -SiC surface layer was obtained.

And film-forming condition No. with which oxidation resistance and surface adhesion were favorable. The 18-20 electrophotographic photoreceptors were evaluated for chargeability in the same manner as in Example 1 after evaluation of oxidation resistance, and ghost evaluation was performed after evaluation of surface adhesion. As a result, the evaluation results were B or more for both ghost evaluation and chargeability evaluation. However, the amount of light output from the pre-exposed LED at the time of charging ability evaluation and ghost evaluation was adjusted to be 2.4 μJ / cm ² .

From this result, Ln (A) calculated from the amount of pre-exposure A absorbed in the region where the atomic density of boron atoms in the photoconductive layer is 9.64 × 10 ¹⁵ atoms / cm ³ or more is −12.0 or more, -4.5 or less, and after adjusting the content of boron atoms contained in the photoconductive layer to a distribution continuously decreasing from the substrate side to the surface side, the Si + C atom density of the surface layer is adjusted to 6. By setting it to 60 × 10 ²² atoms / cm ³ or more, an a-SiC surface layer excellent in the stability of the amount of pre-exposure incident on the electrophotographic photoreceptor can be obtained, and the charging ability can be improved and the ghost can be suppressed. I understand that they are compatible.

<Example 4>
Similarly to Example 3, a positively charged a-Si electrophotographic photoreceptor was produced on a cylindrical substrate using a plasma processing apparatus using a high frequency power source in the RF band as the frequency shown in FIG. At that time, the charge injection blocking layer under the conditions shown in Table 12 described above, the photoconductive layer first region, the photoconductive layer and the second region, performs a film formation in the order of the surface layer, the surface layer during production of the high-frequency power, SiH ₄ flow rate The CH ₄ flow rate was set as shown in Table 17 below.

However, in the first region of the photoconductive layer, the B ₂ H ₆ flow rate with respect to the SiH ₄ flow rate is 0.75 ppm at the position closest to the substrate side, and 0.20 ppm at the position closest to the photoconductive layer second region. The B ₂ H ₆ gas flow rate was continuously decreased linearly. Further, a straight line B ₂ H ₆ gas flow rate as B ₂ H ₆ flow rate to SiH ₄ flow rate at the interface position between the surface layer in the photoconductive layer and the second region is 0.00ppm from 0.20ppm to 0.00ppm Continuously reduced.

  The number of electrophotographic photoreceptors produced was 4 for each film forming condition.

For the electrophotographic photoreceptor produced in Example 4, as in Example 3, C / (Si + C), Si atom density, C atom density, Si + C atom density, H atom ratio, H atom density, and sp ³ property were measured. The oxidation resistance, surface adhesion, Ln (A), gradation and sensitivity were evaluated. The results are shown in Table 18.

  From the results of Table 18, it was found that the gradation is improved by setting C / (Si + C) of the surface layer to 0.61 or more. Further, it was found that when C / (Si + C) of the surface layer is 0.75 or less, light absorption is suppressed and sensitivity is improved.

And the film-forming conditions No. 1 produced in Example 4 were used. The electrophotographic photoreceptors 23 to 28 were subjected to the same chargeability evaluation as in Example 1 after the oxidation resistance evaluation, and the ghost evaluation after the surface adhesion evaluation. As a result, the evaluation result was B or more in both the charging ability evaluation and the ghost evaluation. However, the amount of light output from the pre-exposed LED at the time of charging ability evaluation and ghost evaluation was adjusted to be 2.4 μJ / cm ² .

From this result, Ln (A) calculated from the amount of pre-exposure A reaching an area where the atomic density of boron atoms in the photoconductive layer is 9.64 × 10 ¹⁵ atoms / cm ³ or more is −12.0 or more, − The content of boron atoms contained in the photoconductive layer is adjusted to 4.5 or less and the distribution is continuously reduced from the substrate side to the surface side, and the Si + C atom density of the surface layer is 6.60. on which a × 10 ²² atoms / cm ³ or more, C / a (Si + C) in the above range, it was found that an electrophotographic photoreceptor having excellent gradation and sensitivity.

<Example 5>
Similarly to Example 3, a positively charged a-Si electrophotographic photoreceptor was produced on a cylindrical substrate using a plasma processing apparatus using a high frequency power source in the RF band as the frequency shown in FIG.

At that time, the charge injection blocking layer under the conditions shown in Table 12 described above, the photoconductive layer first region, the photoconductive layer and the second region, performs a film formation in the order of the surface layer, the surface layer during production of the high-frequency power, SiH ₄ flow rate The CH ₄ flow rate was set as shown in Table 19 below.

However, in the first region of the photoconductive layer, the B ₂ H ₆ flow rate with respect to the SiH ₄ flow rate is 0.75 ppm at the position closest to the substrate side, and 0.20 ppm at the position closest to the photoconductive layer second region. The B ₂ H ₆ gas flow rate was continuously decreased linearly. Further, a straight line B ₂ H ₆ gas flow rate as B ₂ H ₆ flow rate to SiH ₄ flow rate at the interface position between the surface layer in the photoconductive layer and the second region is 0.00ppm from 0.20ppm to 0.00ppm Continuously reduced.

  The number of electrophotographic photoreceptors produced was 4 for each film forming condition.

For the electrophotographic photoreceptor produced in Example 5, as in Example 3, C / (Si + C), Si atom density, C atom density, Si + C atom density, H atom ratio, H atom density, and sp ³ property were measured. The oxidation resistance, surface adhesion, Ln (A), gradation and sensitivity were evaluated. The results are shown in Table 21.

<Example 6>
Similarly to Example 3, a positively charged a-Si electrophotographic photoreceptor was produced on a cylindrical substrate using a plasma processing apparatus using a high frequency power source in the RF band as the frequency shown in FIG.

At that time, the charge injection blocking layer under the conditions shown in Table 12 described above, the photoconductive layer first region, the photoconductive layer and the second region, performs a film formation in the order of the surface layer, the surface layer during production of the high-frequency power, SiH ₄ flow rate The CH ₄ flow rate was set as shown in Table 20 below.

However, in the first region of the photoconductive layer, the B ₂ H ₆ flow rate with respect to the SiH ₄ flow rate is 0.75 ppm at the position closest to the substrate side, and 0.20 ppm at the position closest to the photoconductive layer second region. The B ₂ H ₆ gas flow rate was continuously decreased linearly. Further, a straight line B ₂ H ₆ gas flow rate as B ₂ H ₆ flow rate to SiH ₄ flow rate at the interface position between the surface layer in the photoconductive layer and the second region is 0.00ppm from 0.20ppm to 0.00ppm Continuously reduced.

  The number of electrophotographic photoreceptors produced was 4 for each film forming condition.

For the electrophotographic photoreceptor produced in Example 6, as in Example 3, C / (Si + C), Si atom density, C atom density, Si + C atom density, H atom ratio, H atom density, and sp ³ property were measured. The oxidation resistance, surface adhesion, Ln (A), gradation and sensitivity were evaluated. The results are shown in Table 21.

About Example 5 and Example 6, C / (Si + C), Si atom density, C atom density, Si + C atom density, H atom ratio, H atom density, sp ³ property, oxidation resistance, surface adhesion, Ln (A) Table 21 shows the results regarding gradation and sensitivity.

  From the results shown in Table 21, when the H atomic ratio of the surface layer was set to 0.30 or more, the light absorption was suppressed, so that the sensitivity was improved. Moreover, the oxidation resistance and surface adhesion were further improved by setting the H atom ratio of the surface layer to 0.45 or less.

And the film-forming condition No. produced in Example 5 and Example 6 was demonstrated. The electrophotographic photoreceptors Nos. 29 to 36 were subjected to the same chargeability evaluation as in Example 1 after the oxidation resistance evaluation, and the ghost evaluation after the surface adhesion evaluation. As a result, the evaluation result was B or more in both the charging ability evaluation and the ghost evaluation. However, the amount of light output from the pre-exposed LED at the time of charging ability evaluation and ghost evaluation was adjusted to be 2.4 μJ / cm ² .

From this result, Ln (A) calculated from the amount of pre-exposure A reaching an area where the atomic density of boron atoms in the photoconductive layer is 9.64 × 10 ¹⁵ atoms / cm ³ or more is −12.0 or more, − The content of boron atoms contained in the photoconductive layer is adjusted to 4.5 or less and the distribution is continuously reduced from the substrate side to the surface side, and the Si + C atom density of the surface layer is 6.60. By setting the H atom ratio of the surface layer within the above range after setting the number of atoms to 10 ²² atoms / cm ³ or more, an electrophotographic photoreceptor having further excellent sensitivity can be obtained and incident on the electrophotographic photoreceptor. It has been found that the pre-exposure light quantity is excellent in stability.

<Example 7>
Similarly to Example 3, a positively charged a-Si electrophotographic photoreceptor was produced on a cylindrical substrate using a plasma processing apparatus using a high frequency power source in the RF band as the frequency shown in FIG.

At that time, the charge injection blocking layer under the conditions shown in Table 12 described above, the photoconductive layer first region, the photoconductive layer and the second region, performs a film formation in the order of the surface layer, the surface layer during production of the high-frequency power, SiH ₄ flow rate The CH ₄ flow rate was set as shown in Table 22 below.

However, in the first region of the photoconductive layer, the B ₂ H ₆ flow rate with respect to the SiH ₄ flow rate is 0.75 ppm at the position closest to the substrate side, and 0.20 ppm at the position closest to the photoconductive layer second region. The B ₂ H ₆ gas flow rate was continuously decreased linearly. Further, a straight line B ₂ H ₆ gas flow rate as B ₂ H ₆ flow rate to SiH ₄ flow rate at the interface position between the surface layer in the photoconductive layer and the second region is 0.00ppm from 0.20ppm to 0.00ppm Continuously reduced.

  The number of electrophotographic photoreceptors produced was 4 for each film forming condition.

For the electrophotographic photoreceptor produced in Example 7, as in Example 3, C / (Si + C), Si atom density, C atom density, Si + C atom density, H atom ratio, H atom density, and sp ³ property were measured. The oxidation resistance, surface adhesion, Ln (A), gradation and sensitivity were evaluated. The results are shown in Table 24.

<Example 8>
Similarly to Example 3, a positively charged a-Si electrophotographic photoreceptor was produced on a cylindrical substrate using a plasma processing apparatus using a high frequency power source in the RF band as the frequency shown in FIG.

At that time, the charge injection blocking layer under the conditions shown in Table 12 described above, the photoconductive layer first region, the photoconductive layer and the second region, performs a film formation in the order of the surface layer, the surface layer during production of the high-frequency power, SiH ₄ flow rate The CH ₄ flow rate was set as shown in Table 23 below.

However, in the first region of the photoconductive layer, the B ₂ H ₆ flow rate with respect to the SiH ₄ flow rate is 0.75 ppm at the position closest to the substrate side, and 0.20 ppm at the position closest to the photoconductive layer second region. The B ₂ H ₆ gas flow rate was continuously decreased linearly. Further, a straight line B ₂ H ₆ gas flow rate as B ₂ H ₆ flow rate to SiH ₄ flow rate at the interface position between the surface layer in the photoconductive layer and the second region is 0.00ppm from 0.20ppm to 0.00ppm Continuously reduced.

  The number of electrophotographic photoreceptors produced was 4 for each film forming condition.

For the electrophotographic photoreceptor produced in Example 8, as in Example 3, C / (Si + C), Si atom density, C atom density, Si + C atom density, H atom ratio, H atom density, and sp ³ property were measured. The oxidation resistance, surface adhesion, Ln (A), gradation and sensitivity were evaluated. The results are shown in Table 24.

About Example 7 and Example 8, C / (Si + C), Si atom density, C atom density, Si + C atom density, H atom ratio, H atom density, sp ³ property, oxidation resistance, surface adhesion, Ln (A) Table 24 shows the results regarding gradation and sensitivity.

From the results shown in Table 24, the oxidation resistance and surface adhesion were further improved by setting the sp ³ property of the surface layer to 0.70 or less. And when the sp ³ property of the surface layer was 0.20 or more, it was found that oxidation resistance and surface adhesion were good.

And the film-forming condition No. produced in Example 7 and Example 8 was demonstrated. The electrophotographic photoreceptors 37 to 44 were subjected to the same chargeability evaluation as in Example 1 after the oxidation resistance evaluation, and the ghost evaluation after the surface adhesion evaluation. As a result, the evaluation result was B or more in both the charging ability evaluation and the ghost evaluation. However, the amount of light output from the pre-exposed LED at the time of charging ability evaluation and ghost evaluation was adjusted to be 2.4 μJ / cm ² .

From this result, Ln (A) calculated from the amount of pre-exposure A reaching an area where the atomic density of boron atoms in the photoconductive layer is 9.64 × 10 ¹⁵ atoms / cm ³ or more is −12.0 or more, − The content of boron atoms contained in the photoconductive layer is adjusted to 4.5 or less and the distribution is continuously reduced from the substrate side to the surface side, and the Si + C atom density of the surface layer is 6.60. X10 ²² atoms / cm ³ or more, and by setting the sp ³ property of the surface layer in the range of 0.20 or more and 0.70 or less, the amount of pre-exposure light incident on the electrophotographic photoreceptor can be further stabilized. It turns out that it is excellent in property.

1001 ……………………………………………………………………………………………………………………………………………………………………………………… Main charger 1003 ……………………………………………………… · · · Pre-exposure means 1004 · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·· ……………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………… Magnet roller 1008 ……………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………. ………………………………………… Transfer material 1011 …………………………………………………………………………………………………………………………………………………………………………………. ‥‥‥‥‥‥‥‥‥ · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ··························· Fixed Member 1016 ·························································· …… ‥‥‥‥‥‥‥‥‥‥ photoconductive layer 2003 ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ Surface layer 2004 ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ ································································································· …… 2nd area 3100 ························································································································· ‥‥‥‥‥‥‥‥‥‥‥ Cathode Pole 3112 ························································································································· ………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………. ……………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………… Main valve 3119 …………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………. ‥‥‥‥ insulating material 3123 ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ cradle 3200 ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ gas feeder 3211-3215 ... …………………………………………………………………… Mass Flow Controllers 3221 to 3225 ······························································· Valves 3241 to 3245 ‥‥‥‥‥‥‥‥ inlet valve from 3,251 to 3,255 ‥‥‥‥‥‥‥‥‥‥‥‥ outflow valves 3260 ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ auxiliary valve 3261 to 3265 ………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………. Bearings 4002, 4003 ........... Flange 4003 ........................................................ Load cell 4005 ...................................................................................... · · · · · · · Supports 4006, 4007, 4008 · · · · · · · · · Load cells 4009, 4010 4011 ···································································································································· Substrate (conductive substrate)
5002 ……………………………………………………………………………………… Glass substrate

Claims (6)

A latent image is formed on the electrophotographic photosensitive member, a pre-exposure step for removing at least the electrophotographic photosensitive member on the electrophotographic photosensitive member, a main charging step for imparting a positive charge to the electrophotographic photosensitive member, and An image exposure process for forming, a development process for developing the electrostatic latent image with toner, and a charging process for applying a negative charge to the downstream side of the development process and the upstream side of the pre-exposure process. An image forming method comprising:
The electrophotographic photoreceptor is one in which a photoconductive layer made of hydrogenated amorphous silicon containing boron atoms and a surface layer made of hydrogenated amorphous silicon carbide are sequentially formed on at least a substrate,
The boron atom has a distribution in which the content thereof is maximum on the substrate side in the film thickness direction of the photoconductive layer, and continuously decreases linearly or curvedly toward the surface side,
The surface layer has a sum of atomic density of silicon atoms and atomic density of carbon atoms of 6.60 × 10 ²² atoms / cm ³ or more,
Of the pre-exposure light amount irradiated to the electrophotographic photoreceptor in the pre-exposure step, the pre-exposure light amount that reaches the region where the atomic density of boron atoms is 9.64 × 10 ¹⁵ atoms / cm ³ or more is defined as A (μJ / Cm ² ), the following formula (1) is satisfied.
Formula (1) −12.0 ≦ Ln (A) ≦ −4.5 The image forming method according to claim 1, wherein the A satisfies the following expression (2).
Formula (2) −11.0 ≦ Ln (A) ≦ −6.0   3. The image forming method according to claim 1, wherein in the surface layer, a ratio of carbon atoms to a sum of silicon atoms and carbon atoms is 0.61 or more and 0.75 or less.   The ratio of the atomic density of hydrogen atoms to the sum of the atomic density of silicon atoms, the atomic density of carbon atoms, and the atomic density of hydrogen atoms in the surface layer is 0.30 or more and 0.45 or less. The image forming method according to any one of 1 to 3. 5. The image formation according to claim 1, wherein a sum of an atomic density of silicon atoms and an atomic density of carbon atoms is 6.81 × 10 ²² atoms / cm ³ or more in the surface layer. Method. In the surface layer, the ratio of the peak intensity I _D of around 1390 cm ^-1 to the peak intensity I _G near 1480 cm ^-1 in the Raman spectrum, claim 1及至, characterized in that 0.20 to 0.70 The image forming method according to claim 5.