WO2009096552A1

WO2009096552A1 - Electrophotographic photoreceptor, image-forming device provided with the same, and method for manufacturing an electrophotographic photoreceptor

Info

Publication number: WO2009096552A1
Application number: PCT/JP2009/051637
Authority: WO
Inventors: Hiroyuki Nakashima
Original assignee: Kyocera Corporation
Priority date: 2008-01-31
Filing date: 2009-01-30
Publication date: 2009-08-06
Also published as: JPWO2009096552A1; JP5436227B2

Abstract

An electrophotographic photoreceptor (2) is provided with a conductive substrate (20) and a coating layer (21) which coats the conductive substrate (20). The coating layer (21) includes a photosensitive layer (22), a pressure-resistant layer (23) provided between the cylindrical substrate (20) and the photosensitive layer (22), and an a-SiONB containing layer (24) provided between the cylindrical substrate (20) and the pressure-resistant layer (23). The thickness of the a-SiONB containing layer is, for example, 0.15 µm - 1.05 µm.

Description

Electrophotographic photoreceptor, image forming apparatus equipped with the same, and method for producing electrophotographic photoreceptor

The present invention relates to an electrophotographic photosensitive member obtained by coating a conductive substrate with a coating layer including a photosensitive layer. The present invention further relates to an image forming apparatus provided with the electrophotographic photosensitive member.

In an image forming apparatus including an electrophotographic photosensitive member, the electrophotographic photosensitive member is rotated by a drive transmission mechanism, and operations such as charging, exposure, development, transfer, and cleaning are repeatedly performed in synchronization with the rotation cycle. An image is formed on the recording medium.

As an electrophotographic photoreceptor to be mounted on such an image forming apparatus, one in which a coating layer including a charge injection blocking layer and a photoconductive layer is formed on a conductive substrate is known. The charge injection blocking layer is for suppressing the injection of electrons or holes from the conductive substrate into the photoconductive layer. Such a charge injection blocking layer is composed of, for example, a Si-based inorganic material such as amorphous silicon (a-Si), and the adjustment of the conductivity type is performed by group 13 elements of the periodic table or periodic table. It is carried out by containing a group 15 element. The charge injection blocking layer further has a multilayer structure of a barrier layer containing a group 13 element of the periodic table or a group 15 element of the periodic table and an electron blocking layer located between the barrier layer and the conductive substrate. Things have also been proposed.

In recent years, electrophotographic photoreceptors tend to reduce the thickness of the entire coating layer including the charge injection blocking layer in order to meet the demand for higher image quality. However, when the thickness of the charge injection blocking layer is reduced, the withstand voltage is lowered and the image quality tends to deteriorate. On the other hand, in order to improve the withstand voltage of the charge injection blocking layer, an amorphous nitrogen silicon layer may be formed between the charge injection blocking layer and the conductive substrate.

However, since amorphous nitrogen silicon tends to have poor adhesion to aluminum or aluminum alloy, which is generally used as a material for conductive substrates, it may cause defects such as film peeling. In addition, since amorphous nitrogen silicon tends to have a high insulating property, there may be a case where sufficient electrical characteristics as an electrophotographic photosensitive member (for example, potential characteristics after exposure or neutralization, or dark part potential characteristics) cannot be obtained.

Japanese Patent Publication No. 03-068379 Japanese Patent Laid-Open No. 05-232729

The present invention can suppress the occurrence of film peeling and the deterioration of electrical characteristics while maintaining good withstand voltage characteristics in an electrophotographic photoreceptor even when the thickness of the coating layer is reduced in order to achieve high image quality. It is an object to provide an electrophotographic photosensitive member and an image forming apparatus.

The electrophotographic photosensitive member according to an embodiment of the present invention includes a conductive substrate and a coating layer that covers the conductive substrate. The coating layer includes a photosensitive layer, a pressure-resistant layer, and an a-SiONB-containing layer. The pressure-resistant layer is located between the conductive substrate and the photosensitive layer. The a-SiONB-containing layer is located between the conductive substrate and the breakdown voltage layer.

An image forming apparatus according to an aspect of the present invention includes the electrophotographic photosensitive member.

An electrophotographic photoreceptor manufacturing method according to an aspect of the present invention includes a first step of forming an a-SiONB-containing layer on a conductive substrate and a second step of forming a pressure-resistant layer on the a-SiONB-containing layer. And a third step of forming a photosensitive layer on the pressure-resistant layer. The first step is performed by supplying source gas to the reaction chamber containing the conductive substrate and supplying high-frequency power to the conductive substrate. The high frequency power is set to 50 W or more and 400 W or less.

In the electrophotographic photoreceptor according to an embodiment of the present invention, the withstand voltage characteristic in the coating layer can be appropriately maintained because the withstand voltage layer is provided between the conductive substrate and the photosensitive layer. In addition, since this electrophotographic photoreceptor includes an a-SiONB-containing layer between the conductive substrate and the pressure-resistant layer, the occurrence of film peeling can be suppressed.

In the image forming apparatus according to an aspect of the present invention, an electrophotographic photosensitive member that suppresses the occurrence of film peeling while appropriately maintaining the withstand voltage characteristics is used, thereby suppressing the occurrence of image defects. High-quality images can be formed.

In the method for producing an electrophotographic photosensitive member according to an aspect of the present invention, when an a-SiONB-containing layer is formed on a conductive substrate, high-frequency power (set to 50 W or more and 400 W or less) is supplied to the conductive substrate. . The electrophotographic photosensitive member produced in this way is excellent in electrical characteristics, and the occurrence of peeling of the coating layer is also suppressed.

1 is a schematic configuration diagram illustrating an image forming apparatus according to an embodiment of the present invention. 1 is a cross-sectional view of an electrophotographic photosensitive member according to an embodiment of the present invention and an enlarged view of a main part thereof. It is a graph which shows the measurement result of the dark part electric potential in Example 2, and the electric potential after static elimination. 6 is a graph showing measurement results of potential after static elimination in Example 3.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 2 Electrophotographic photoreceptor 20 Cylindrical base | substrate (electroconductive base | substrate)
21 Coating layer 22 Photosensitive layer (of coating layer) 23 Pressure-resistant layer (of coating layer) 24 a-SiONB containing layer (of coating layer) 25 Charge injection blocking layer (of photosensitive layer) 26 Photoconductive layer (of photosensitive layer)

Hereinafter, the image forming apparatus and the electrophotographic photosensitive member according to the present invention will be specifically described with reference to the accompanying drawings.

The image forming apparatus 1 shown in FIG. 1 employs the Carlson method as an image forming method. The image forming apparatus 1 includes an electrophotographic photosensitive member 2, a charger 10, an exposure device 11, a developing device 12, a transfer device 13, a fixing device 14, a cleaning device 15, and a static eliminator 16.

The electrophotographic photoreceptor 2 forms an electrostatic latent image based on an image signal, and can be rotated in the direction of arrow A in FIG. Details of the electrophotographic photosensitive member 2 will be described later.

The charger 10 is used for uniformly charging the surface of the electrophotographic photosensitive member 2 positively or negatively according to the type of a photoconductive layer 26 (see FIG. 2) of the electrophotographic photosensitive member 2 described later. Is. The charger 10 is disposed in close contact with the electrophotographic photosensitive member 2 so as to press the electrophotographic photosensitive member 2. For example, the surface of the metal roller is covered with conductive rubber and PVDF (polyvinylidene fluoride). The charged voltage of the electrophotographic photosensitive member 2 by the charger 10 is, for example, 200 V or more and 1000 V or less in absolute value.

As the charger 10, a colontron for generating a corona discharge can be used. In this case, the charger 10 includes a discharge wire stretched so as to extend in the axial direction of the electrophotographic photosensitive member 2, for example.

The exposure device 11 is for forming an electrostatic latent image on the electrophotographic photosensitive member 2, and can emit light having a specific wavelength (for example, 650 nm or more and 780 nm or less). According to this exposure device 11, an electrostatic latent image as a potential contrast is formed by irradiating the surface of the electrophotographic photosensitive member 2 with light in accordance with an image signal to attenuate the potential of the light irradiated portion. As the exposure device 11, for example, an LED head in which LED elements capable of emitting light having a wavelength of about 680 nm are arranged at a density of 600 dpi can be employed. Of course, as the exposure device 11, a device capable of emitting laser light can be used.

In addition, instead of the exposure unit 11 such as an LED head, an optical system including a laser beam and a polygon mirror, or an optical system including a lens and a mirror that transmits reflected light from a document is used. The image forming apparatus can also be used.

The developing device 12 is for developing the electrostatic latent image of the electrophotographic photosensitive member 2 to form a toner image. The developing device 12 includes a magnetic roller 12 A that magnetically holds a developer (toner), wheels (not shown) called rollers for controlling a gap with the electrophotographic photosensitive member 2, and the like.

The developer constitutes a toner image formed on the surface of the electrophotographic photosensitive member 2 and is frictionally charged in the developing device 12. As the developer, a two-component developer composed of a magnetic carrier and an insulating toner or a one-component developer composed of a magnetic toner can be used.

The magnetic roller 12A plays a role of transporting the developer to the surface of the electrophotographic photosensitive member 2.

In the developing device 12, the frictionally charged toner is conveyed to the developing area of the electrophotographic photosensitive member 2 in the form of a magnetic brush adjusted to a constant spike length by the magnetic roller 12A, and is electrostatically attracted with the electrostatic latent image. The toner adheres to the photoreceptor surface and is visualized. The charge polarity of the toner image is opposite to the charge polarity of the surface of the electrophotographic photosensitive member 2 when image formation is performed by regular development. When the image formation is performed by reversal development, the electrophotographic photosensitive member is charged. The surface of the body 2 has the same polarity as the charged polarity.

The developing device 12 adopts a dry development method, but may adopt a wet development method using a liquid developer.

The transfer device 13 is for transferring the toner image of the electrophotographic photosensitive member 2 to the recording medium P supplied to the transfer region between the electrophotographic photosensitive member 2 and the transfer device 13. The transfer unit 13 includes a transfer charger 13A and a separation charger 13B. In the transfer device 13, the back surface (non-recording surface) of the recording medium P is charged with a polarity opposite to that of the toner image in the transfer charger 13 A, and the toner is applied onto the recording medium P by electrostatic attraction between the charged charge and the toner image. The image is transferred. In the transfer device 13, simultaneously with the transfer of the toner image, the back surface of the recording medium P is AC-charged in the separation charger 13 B, and the recording medium P is quickly separated from the surface of the electrophotographic photoreceptor 2.

The transfer unit 13 may be a transfer roller that is driven by the rotation of the electrophotographic photosensitive member 2 and disposed with a small gap (usually 0.5 mm or less) from the electrophotographic photosensitive member 2. It is. The transfer roller in this case is configured to apply a transfer voltage that attracts the toner image on the electrophotographic photosensitive member 2 onto the recording medium P by, for example, a DC power source. When a transfer roller is used, a transfer separation device such as the separation charger 13B may be omitted.

The fixing device 14 is for fixing the toner image transferred to the recording medium P to the recording medium P, and includes a pair of fixing

rollers

14A and 14B. The fixing

rollers

14A and 14B are, for example, coated on a metal roller with a fluorine resin or the like. In the fixing device 14, the toner image can be fixed to the recording medium P by heat or pressure by passing the recording medium P between the pair of fixing rollers 14 A and 14 B.

The cleaning device 15 is for removing toner remaining on the surface of the electrophotographic photosensitive member 2, and includes a cleaning blade 15A.

The cleaning blade 15A serves to scrape residual toner from the surface layer 27 (see FIG. 2) of the electrophotographic photosensitive member 2. The cleaning blade 15A is made of, for example, a rubber material whose main component is polyurethane resin. In the cleaning blade 15A according to the present embodiment, the thickness of the tip portion in contact with the surface layer 27 (see FIG. 2) is 1.0 mm or more and 1.2 mm or less. The cleaning blade 15A according to the present embodiment has a blade linear pressure of 14 gf / cm (generally 5 gf / cm or more and 30 gf / cm or less). The cleaning blade 15A according to the present embodiment has a JIS hardness of 74 degrees (preferable range 67 degrees or more and 84 degrees or less).

The static eliminator 16 is for removing the surface charge of the electrophotographic photosensitive member 2. The static eliminator 16 uniformly irradiates the entire surface of the electrophotographic photosensitive member 2 with a light source such as an LED to remove the surface charge (residual electrostatic latent image) of the electrophotographic photosensitive member 2. It is configured.

As shown in FIG. 2, the electrophotographic photosensitive member 2 has a cylindrical substrate 20 and a coating layer 21.

The cylindrical substrate 20 forms the skeleton of the electrophotographic photosensitive member 2 and has conductivity at least on the surface. The cylindrical base body 20 may be entirely formed of a conductive material, or may be formed by forming a conductive film on the surface of a cylindrical body formed of an insulating material. Examples of the conductive material for the cylindrical substrate 20 include metal materials such as Al or SUS (stainless steel), Zn, Cu, Fe, Ti, Ni, Cr, Ta, Sn, Au, and Ag, and those metals. Alloy materials can be used. Examples of the insulating material for the cylindrical substrate 20 include resin, glass, and ceramics. Examples of the material for the conductive film include transparent conductive materials such as ITO (Indium Tin Oxide) and SnO _{2 in} addition to the metals exemplified above. These transparent conductive materials can be deposited on the surface of an insulating cylinder by a known method such as vapor deposition.

However, the entire cylindrical base 20 is preferably formed of an Al alloy material (for example, an Al—Mn alloy, an Al—Mg alloy, or an Al—Mg—Si alloy). By doing so, the electrophotographic photosensitive member 2 can be manufactured at a low weight and at a low cost.

Such a cylindrical substrate 20 made of an Al alloy material can be formed by, for example, casting, homogenizing treatment, hot extrusion processing, and cold drawing processing, and performing softening processing as necessary.

The coating layer 21 includes a photosensitive layer 22, a pressure-resistant layer 23, and an a-SiONB containing layer 24.

The photosensitive layer 22 includes a charge injection blocking layer 25, a photoconductive layer 26 and a surface layer 27. The thickness of the photosensitive layer 22 is preferably set to 15 μm or more and 90 μm or less. When the thickness of the photosensitive layer 22 is set in the range of 15 μm or more and 90 μm or less, for example, it is possible to appropriately suppress the occurrence of interference fringes in a recorded image without providing a long wavelength light absorption layer, and in addition, a film caused by stress It can suppress appropriately that peeling arises.

The charge injection blocking layer 25 is for suppressing injection of electrons or holes from the cylindrical substrate 20 into the photoconductive layer 26, and is formed to have a thickness of 1 μm to 10 μm, for example. Various materials can be used as the charge injection blocking layer 25 depending on the material of the photoconductive layer 26. For example, if the photoconductive layer 26 is formed using an a-Si-based material, the charge injection blocking layer 25 can be used. The layer 25 is also preferably made of an inorganic material such as an a-Si material. By doing so, it is possible to obtain electrophotographic characteristics excellent in adhesion between the pressure-resistant layer 23 and the photoconductive layer 26 described later.

In the case where the a-Si based charge injection blocking layer 25 is provided, as compared with the a-Si based photoconductive layer 26, more Group 13 elements of the periodic table (hereinafter abbreviated as “Group 13 element”) or The conductivity type is adjusted by adding a Group 15 element (hereinafter abbreviated as “Group 15 element”) in the periodic table, and a large amount of carbon (C), nitrogen (N), or oxygen (O) is included. To increase the resistance.

When the charge injection blocking layer 25 is formed entirely as an inorganic material, for example, a glow discharge decomposition method, various sputtering methods, various vapor deposition methods, an ECR method, a photo CVD method, a catalytic CVD method, or a reactive vapor deposition method is known. It can be formed by a film formation technique.

Note that the charge injection blocking layer 25 is optional and not necessarily required. Further, a long wavelength light absorption layer may be provided in place of the charge injection blocking layer 25. When this long-wavelength light absorption layer is provided, long-wavelength light incident at the time of exposure (referred to as light having a wavelength of 0.8 μm or more) is reflected by the outer peripheral surface of the cylindrical substrate 20, and interference fringes are generated in the recorded image. This can be suppressed.

The photoconductive layer 26 is used for generating electrons such as free electrons or holes when electrons are excited by irradiation of light such as laser light from the exposure device 11, and is formed to have a thickness of 10 μm to 80 μm, for example. ing. The photoconductive layer 26 is formed of, for example, an a-Si-based material, an amorphous selenium-based (a-Se-based) material such as a-Se, Se-Te, and As ₂ Se ₃ or a periodic table such as ZnO, CdS, or CdSe. It is formed of a compound of a group 12 element and a group 16 element of the periodic table. As the a-Si material, a-Si, a-SiC, a-SiN, a-SiO, a-SiGe, a-SiCN, a-SiNO, a-SiCO, a-SiCNO, and the like can be used. . In particular, when the photoconductive layer 26 is formed of a-Si or an a-Si alloy material in which an element such as C, N, or O is added to a-Si, excellent electrophotographic characteristics can be stably obtained. In addition, when the surface layer 27 is formed of a-SiC (particularly a-SiC: H), the compatibility with the surface layer 27 is excellent. Here, electrophotographic characteristics include high photosensitivity characteristics, high-speed response, repeat stability, heat resistance, durability, and the like.

When the photoconductive layer 26 is formed entirely as an inorganic substance, for example, a glow discharge decomposition method, various sputtering methods, various vapor deposition methods, an ECR method, a photo CVD method, a catalytic CVD method, or a reactive vapor deposition method may be used. It can be formed by a film technique. In forming the photoconductive layer 26, hydrogen (H) or a halogen element (F, Cl) may be contained in the film for 1 to 40 atom% for dangling bond termination. In forming the photoconductive layer 26, a group 13 element or a group 15 element is used to obtain desired characteristics of the electrical characteristics (dark conductivity or photoconductivity, etc.) and optical band gap of each layer. Of 0.1 ppm or more and 20000 ppm or less, or the content of elements such as C, N, and O may be adjusted in the range of 0.01 ppm to 100 ppm. About elements, such as C, N, and O, you may make it contain so that a concentration gradient may arise in the thickness direction of a layer, and the average content of the whole layer should just be in the said range.

Further, as the group 13 element and the group 15 element, boron (B) and phosphorus (P) are used in that they are excellent in covalent bonding, can change the semiconductor characteristics sensitively, and can provide excellent photosensitivity. Is desirable. When a Group 13 element and a Group 15 element are contained together with elements such as C, N, and O, the Group 13 element is preferably 0.1 ppm or more and 20000 ppm or less, and the Group 15 element is 0.1 ppm. It is preferably 10000 ppm or less.

When the photoconductive layer 26 does not contain an element such as C, N, or O or contains a trace amount (0.01 ppm or more and 100 ppm or less), the content of the Group 13 element is 0.01 ppm or more and 200 ppm or less, The content of the group element is preferably 0.01 ppm or more and 100 ppm or less. The content of these elements may have a concentration gradient in the layer thickness direction. In that case, the average content of the entire layer may be within the above range.

When the photoconductive layer 26 is formed of an a-Si-based material, μc-Si (microcrystalline silicon) may be included. In that case, dark conductivity and photoconductivity can be increased. There is an advantage that the degree of freedom in designing the photoconductive layer 26 is increased. Such μc-Si can be formed by adopting the same formation method as described above and changing the film formation conditions. For example, the glow discharge decomposition method can be formed by setting the temperature and high-frequency power of the cylindrical substrate 20 higher than in the case of a-Si and increasing the flow rate of hydrogen as a dilution gas. In addition, when μc-Si is included, an impurity element similar to the above may be added.

The photoconductive layer 26 may have a form in which the above-described inorganic material is made into particles and dispersed in a resin. The photoconductive layer 26 does not necessarily contain an inorganic material, and may be formed as a photoconductive layer using an organic photoconductive material, for example. Examples of the organic photoconductive substance include a low molecular organic material such as a photoconductive polymer represented by poly-N-vinylcarbazole and 2,5-bis (p-diethylaminophenyl) -1,3,4-oxadiazole. A photoconductive substance can be used. The organic photoconductive substance can also be used in combination with various dyes or pigments.

The surface layer 27 is for preventing the photoconductive layer 26 from being frictioned or worn. The surface layer 27 is formed to be 0.2 μm or more and 1.5 μm or less in thickness by an inorganic material typified by an a-Si based material such as a-SiC. By setting the thickness of the surface layer 27 to 0.2 μm or more, it is possible to suppress the occurrence of image scratches and image density unevenness due to printing. By setting the thickness of the surface layer 27 to 1.5 μm or less, it is possible to improve the initial characteristics (image failure due to residual potential, etc.). The thickness of the surface layer 27 is preferably 0.5 μm or more and 1.0 μm or less.

Such a surface layer 27 is preferably formed of a-SiC: H containing hydrogen in a-SiC. When the element ratio is expressed as a composition formula a-Si _1-X C _X : H, a-SiC: H has an X value of 0.55 or more and less than 0.93, for example. By setting the X value within the range of 0.55 or more and less than 0.93, it is possible to obtain appropriate hardness as the surface layer 27, and sufficiently ensure the durability of the surface layer 27 and thus the electrophotographic photosensitive member 2. Will be able to. Preferably, the X value is 0.6 or more and 0.7 or less. When the surface layer 27 is formed of a-SiC: H, the H content is preferably set to about 1 atomic% or more and 70 atomic% or less. Within this range, the number of Si—H bonds is smaller than that of Si—C bonds, and trapping of charges generated when the surface of the surface layer 27 is irradiated with light can be suppressed, and residual potential is prevented. It is preferable in that it can be performed. According to the knowledge of the present inventors, better results can be obtained when the H content is about 45 atomic% or less.

Such an a-SiC: H surface layer 27 is formed, for example, by a glow discharge decomposition method, various sputtering methods, various vapor deposition methods, an ECR method, an optical method, as in the case where the photoconductive layer 26 is formed of an a-Si material. The film can be formed by a known film formation method such as a CVD method, a catalytic CVD method, or a reactive vapor deposition method.

The surface layer 27 is also usually formed of an organic material when the photoconductive layer 26 is formed using an organic photoconductive substance. Examples of the organic material in this case include a curable resin. As the curable resin, an acrylic resin, a phenol resin, an epoxy resin, a silicone resin, or a urethane resin can be used.

The breakdown voltage layer 23 is for improving the breakdown voltage characteristics in the coating layer 21 and is formed between the photosensitive layer 22 (the charge injection blocking layer 25 in this embodiment) and the a-SiONB containing layer 24. . The breakdown voltage layer 23 includes, for example, amorphous silicon nitride (hereinafter simply referred to as “a-SiN”). The ratio (N / (Si + N)) of the number of nitrogen atoms to the total number of nitrogen atoms and silicon atoms in the withstand voltage layer 23 is, for example, not less than 0.01 and not more than 0.55. By setting the ratio in such a range, it is possible to appropriately ensure the withstand voltage characteristics in the coating layer 21 and appropriately suppress the occurrence of residual potential. Preferably, the ratio (N / (Si + N)) in the breakdown voltage layer 23 is set to 0.01 or more and 0.35 or less.

The thickness of the withstand voltage layer 23 is, for example, 0.5 μm or more from the viewpoint of suppressing the generation of the residual potential while appropriately maintaining the withstand voltage characteristics required for the withstand voltage layer 23 and reducing the overall thickness of the covering layer 21. 2 μm or less.

The pressure-resistant layer 23 also preferably contains as little as possible a Group 13 element and a Group 15 element other than nitrogen, and is preferably substantially composed of a-SiN. This is to ensure good withstand voltage characteristics. Of course, the withstand voltage layer 23 may be formed of a material other than a-SiN as long as the intended withstand voltage function can be ensured. Examples of materials other than this a-SiN include a-SiC, a-SiO, a-SiCO, and a-SiON.

Such a pressure resistant layer 23 can be formed by a known film forming method, as in the case where the photoconductive layer 26 is formed of an a-Si material. Examples of the known film formation method include a glow discharge decomposition method, various sputtering methods, various vapor deposition methods, an ECR method, a photo CVD method, a catalytic CVD method, and a reactive vapor deposition method.

Further, the ratio of nitrogen atoms to silicon atoms in the pressure-resistant layer 23 can be selected, for example, by appropriately adjusting the ratio of nitrogen-containing gas and silicon-containing gas when forming the pressure-resistant layer 23. The thickness of the pressure-resistant layer 23 can be selected, for example, by appropriately adjusting the film formation time when forming the pressure-resistant layer 23 or the temperature of the cylindrical substrate 20.

The a-SiONB-containing layer 24 is for improving the adhesion between the conductive substrate 20 and the pressure-resistant layer 23, and is formed between the conductive substrate 20 and the pressure-resistant layer 23. The a-SiONB containing layer 24 is formed as containing a-SiONB. The thickness of the a-SiONB containing layer 24 is 1.05 μm or less, preferably 0.15 μm or more and 1.05 μm or less. When the thickness of the a-SiONB-containing layer 24 is 1.05 μm or less, the surface potential of the electrophotographic photosensitive member 2 after exposure can be suppressed from becoming higher than necessary, and accordingly, the image forming density is lowered. Image deterioration can be suppressed. On the other hand, if the thickness of the a-SiONB-containing layer 24 is 0.15 μm or more, it is possible to prevent the coating layer 21 from being peeled off from the cylindrical substrate 20.

The N element content in the a-SiONB-containing layer 24 is, for example, 0.630% or more, preferably 0.720% or more and 10.500 when the Si element content is 100 on the basis of the number of atoms. % Or less. If the content of the N element is set within such a range, the occurrence of film peeling can be suppressed while the insulation of the a-SiONB-containing layer 24 is appropriately maintained by the N element.

The content of the O element in the a-SiONB-containing layer 24 is, for example, 1.05% or more, preferably 1.20% or more and 15.00 based on the number of atoms, when the Si element content is 100. % Or less. If the content of the O element is set in such a range, the a-SiONB-containing layer 24 can improve the adhesion between the cylindrical substrate 20 and the pressure-resistant layer 23, so that the occurrence of film peeling is suppressed. can do.

The content of B element in the a-SiONB-containing layer 24 is, for example, 200 ppm to 1000 ppm, preferably 350 ppm to 700 ppm, when the Si element content is 100, based on the number of atoms. If the B element content is set within such a range, the electrical characteristics of the a-SiONB-containing layer 24 (for example, after exposure and after static elimination are maintained while appropriately maintaining the withstand voltage characteristics of the a-SiONB-containing layer 24. Potential characteristic or dark part potential characteristic) can be improved.

The content of N element, O element, and B element in the a-SiONB-containing layer 24 may have a concentration gradient over the layer thickness direction, and in this case, the average content of the entire layer may be within the above range. .

The a-SiONB-containing layer 24 may be formed as a layer substantially made of a-SiONB, or may be formed as a layer containing elements other than Si element, O element, N element and B element. Examples of elements other than Si element, O element, N element, and B element include a small amount of Group 13 element or Group 15 element other than B element and N element. However, the content of elements other than Si element, O element, N element and B element is preferably set to 100 ppm or less.

Such an a-SiONB-containing layer 24 can be formed by a well-known film forming method, like the photoconductive layer 26. Here, as a known film forming method, a glow discharge decomposition method, various sputtering methods, various vapor deposition methods, an ECR method, a photo CVD method, a catalytic CVD method, a reactive vapor deposition method, and the like can be given.

The ratio and content of Si atoms, O atoms, N atoms, and B atoms in the a-SiONB-containing layer 24 are, for example, the ratios of nitrogen-containing gas, boron-containing gas, and silicon-containing gas when the pressure-resistant layer 23 is formed. It can select by adjusting suitably. The thickness of the a-SiONB-containing layer 24 can be selected, for example, by appropriately adjusting the film formation time when forming the a-SiONB-containing layer 24 or the temperature of the cylindrical substrate 20.

When the a-SiONB-containing layer 24 is formed, for example, by glow discharge decomposition, the source gas is supplied with the cylindrical substrate 20 contained in the reaction chamber, and high-frequency power is supplied to the cylindrical substrate 20. It is formed by.

As the source gas, for example, a silicon compound such as SiH ₄ containing Si element, a nitrogen oxide compound containing N element and O element, or a boron compound such as B ₂ H ₆ containing B element is used. Accordingly, one containing a diluent gas such as H ₂ or He is used. The composition of the source gas may be appropriately selected according to the composition of the a-SiONB-containing layer 24 to be formed, and may contain a C compound containing a C element such as CH ₄ or other elements. .

The high frequency power supplied to the cylindrical substrate 20 is set to 50 W or more, preferably 150 W or more and 400 W or less, for example, in the case of a high frequency of 13.56 Hz. When the a-SiONB-containing layer 24 is formed by supplying high frequency power in such a range to the cylindrical substrate 20, the electrophotographic photosensitive member 2 having excellent electrical characteristics can be provided, and the coating from the cylindrical substrate 20 can be provided. Generation | occurrence | production of the film peeling of the layer 21 can be suppressed. In order to obtain such an effect more reliably, it is preferable to set the flow rate of the Si compound per 1 W of high-frequency power to 2.5 sccm or more and 13.3 sccm or less.

The pressure in the reaction chamber when forming the a-SiONB-containing layer 24 is set to, for example, 40.0 Pa to 146.7 Pa, preferably 53.3 Pa to 133.3 Pa. If the a-SiONB-containing layer 24 is formed by setting the pressure in the reaction chamber within such a range, the electrophotographic photoreceptor 2 having excellent electrical characteristics can be provided, and the occurrence of film peeling can be suppressed. .

The film formation time of the a-SiONB containing layer 24 is set to 3 minutes or more, for example. If the a-SiONB-containing layer 24 is formed by setting the pressure in the reaction chamber in such a range, the a-SiONB-containing layer 24 can be formed to a thickness that can suppress the occurrence of film peeling of the coating layer 21, for example, 0.1-μm or more. A SiONB-containing layer 24 can be formed. However, if the film formation time is unnecessarily prolonged, the a-SiONB-containing layer 24 becomes too thick, the surface potential of the electrophotographic photoreceptor 2 after exposure becomes higher than necessary, and the image density decreases. There is a fear. Accordingly, the film formation time of the a-SiONB-containing layer 24 is preferably set to 44 minutes or less so that the potential after exposure is in an appropriate range.

Since the electrophotographic photoreceptor 2 includes the pressure-resistant layer 23 between the cylindrical substrate 20 and the photosensitive layer 22, the withstand voltage characteristics in the coating layer 21 can be appropriately maintained. In addition, since the electrophotographic photoreceptor 2 includes the a-SiONB-containing layer 24 between the cylindrical substrate 20 and the pressure-resistant layer 23, it is possible to suppress the covering layer 21 from being peeled off from the cylindrical substrate 20. .

On the other hand, in the image forming apparatus 1, since the electrophotographic photosensitive member 2 is used in which the withstand voltage characteristics are appropriately maintained and the occurrence of film peeling is suppressed, the occurrence of image defects is suppressed and high quality is achieved. It is possible to form a clear image.

In this example, the influence of the contents of O element and N element in the a-SiONB containing layer on film peeling was examined.

[Creation of electrophotographic photoreceptor]
The electrophotographic photosensitive member has a coating layer formed on an aluminum drawn tube (cylindrical substrate) having the dimensions shown in Table 1 below using a glow discharge decomposition apparatus under the conditions shown in Tables 2 and 3 below. Created by forming. As the cylindrical substrate, a substrate whose outer peripheral surface was mirror-finished and cleaned was used. In addition, the coating layer was constituted by an a-SiONB-containing layer, a pressure-resistant layer, a charge injection blocking layer, a photoconductive layer, and a surface layer. The contents of O element and N element in the a-SiONB-containing layer were adjusted by the flow rate of NO when forming the a-SiONB-containing layer.

[Presence or absence of film peeling]
The film peeling was confirmed visually and with an optical microscope (“MMFP-TR”; manufactured by OLYMPAS). As for the evaluation results of film peeling, “○” indicates that there is no film peeling, “△” indicates that there is no problem in actual use, and “Δ” indicates that there is a problem in actual use. These are shown in Table 3 as “x”.

As can be seen from Table 3, the contents of O element and N element in the a-SiONB containing layer are 1.05% or more and 0.630% or more, respectively, when the Si element is 100 based on the number of atoms. If so, there was no practical problem with respect to peeling of the coating layer. In particular, when the contents of O element and N element in the a-SiONB containing layer are 1.20% or more and 0.720% or more, respectively, the coating layer does not peel off at all or hardly occurs. became.

Therefore, the content of the O element and the N element in the a-SiONB-containing layer is 1.05 when the Si element is 100 based on the number of atoms from the viewpoint of suppressing the occurrence of peeling of the coating layer. % Or more and 0.630% or more, and more preferably 1.20% or more and 0.720% or more, respectively. Note that if the NO / SiH ₄ flow rate ratio exceeds 0.300, the risk of explosion in manufacturing increases, so that manufacturing becomes substantially difficult.

In this example, the influence of the B element content in the a-SiONB containing layer on the electrical characteristics was examined.

[Creation of electrophotographic photoreceptor]
The electrophotographic photoreceptor was prepared under the conditions shown in Tables 1 and 2 basically in the same manner as in Example 1. However, when forming the a-SiONB-containing layer, the content of B element was adjusted by the flow rate of B ₂ H ₆ when forming the a-SiONB-containing layer, and the NO flow rate was fixed at 200 sccm.

[Evaluation of electrical characteristics]
Electrical characteristics were evaluated as dark potential and post-static potential. The dark portion potential and the post-static potential were measured in a state where the electrophotographic photosensitive member was incorporated in a potential measuring machine (manufactured by Kyocera Corporation). The dark portion potential was measured as a potential after charging the surface of the electrophotographic photosensitive member to 500 V using a non-contact type surface potential meter (“MODEL 344”: manufactured by TREK). The post-charge potential was measured using a contact type surface potential meter (“MODEL 344”: manufactured by TREK Co., Ltd.) as the potential after the surface of the charged electrophotographic photosensitive member was discharged. The measurement results of the dark part potential and the post-static charge potential are shown in FIG.

As shown in FIG. 3, the dark portion potential and the potential after static elimination increased as the B element content in the a-SiONB-containing layer increased. If threshold values that do not cause any problem in image formation are set to 500 V or more for the dark potential and 80 V or less for the potential after static elimination, the content of B element in the a-SiONB-containing layer is determined based on the number of atoms. It is understood that the content of B should be 200 ppm or more and 1000 ppm or less when the content is 100, and in order to obtain a better image, the content of B element with respect to Si element should be set to 350 ppm or more and 700 ppm or less.

In this example, the influence of the thickness of the a-SiONB-containing layer on the image characteristics was examined.

[Creation of electrophotographic photoreceptor]
The electrophotographic photoreceptor was prepared under the conditions shown in Tables 1 and 2 basically in the same manner as in Example 1. However, when the a-SiONB-containing layer was formed, the thickness of the a-SiONB-containing layer was adjusted by the film formation time, and the NO flow rate was fixed at 200 sccm.

[Evaluation of image characteristics]
Image characteristics were evaluated as potential after static elimination. The potential after static elimination was measured in the same manner as in Example 2. The measurement results of the potential after static elimination are shown in FIG.

As shown in FIG. 4, the potential after static elimination increased as the thickness of the a-SiONB-containing layer increased. Assuming that the threshold value of the post-static potential, which has no practical problem in image formation, is set to 80 V or less, the thickness of the a-SiONB-containing layer may be set to 1 μm or less. In order to obtain a better image, the thickness of the a-SiONB-containing layer may be set to 0.5 μm or less.

In this example, when the a-SiONB-containing layer was formed using a glow discharge decomposition apparatus, the influence of the magnitude of the high-frequency power on the occurrence of film peeling and the electric characteristic unevenness in the electrophotographic photosensitive member was examined.

[Creation of electrophotographic photoreceptor]
The electrophotographic photoreceptor was prepared under the same conditions as in Example 1 except for the a-SiONB-containing layer. The a-SiONB-containing layer was formed under the conditions shown in Table 4 except for the magnitude of the high-frequency power. The high frequency power was set in the range shown in Table 5.

[Presence or absence of film peeling]
The presence or absence of film peeling was examined in the same manner as in Example 1. Table 5 shows the evaluation results of the presence or absence of film peeling.

[Electrical characteristics unevenness]
The electrical property unevenness was evaluated by a potential measuring device (manufactured by Kyocera Corporation). The rotational speed of the electrophotographic photosensitive member was 1443.6 mm / sec. The electrophotographic photosensitive member was charged by corona discharge. This corona discharge was performed using a charger having a grid voltage of 800 V ± 10 V and a grid opening efficiency of 95%. As a power source, a high voltage power source “MODEL610E” manufactured by TREK was used. The exposure of the electrophotographic photosensitive member was performed by continuously lighting a halogen lamp (12 V, 100 W) as a light source and using an interference filter having a wavelength of 720 nm. The exposure energy was set to 1.04 μJ / cm ² . The neutralization was performed using an LED unit with a transparent filter (wavelength: 660 nm, light amount: 600 μW / cm ² ) as a light source. The photoreceptor temperature at the time of measurement was set to 42 ± 2 ° C. The surface potential was measured using a TREK probe “MODEL6000B-7C”, and the measurement position was 58 ° after exposure. The evaluation results of the electrical characteristic unevenness are shown in Table 5.

As can be seen from Table 5, the magnitude of the high-frequency power may be set to 50 W or more and 400 W or less, and the magnitude of the high-frequency power may be set to 150 W or more and 400 W in order to suppress the peeling of the coating layer and the occurrence of uneven electrical characteristics. If set to the following, the occurrence of film peeling can be suppressed more favorably.

In this example, when an a-SiONB-containing layer is formed using a glow discharge decomposition apparatus, the influence of the Si flow rate in the source gas per 1 W of high-frequency power on the occurrence of film peeling and resolution on the electrophotographic photoreceptor. investigated.

[Creation of electrophotographic photoreceptor]
The electrophotographic photoreceptor was prepared under the same conditions as in Example 1 except for the a-SiONB-containing layer. The a-SiONB-containing layer was formed under the conditions shown in Table 6 except for the magnitude of the high-frequency power. The high frequency power was set in the range shown in Table 7.

[Presence or absence of film peeling]
The presence or absence of film peeling was examined in the same manner as in Example 1. Table 7 shows the evaluation results of the presence or absence of film peeling.

[resolution]
The resolution was evaluated by confirming the line width or dot of an image formed using “PS5600A” manufactured by Fuji Xerox Co., Ltd. using “personal IAS (Image Analysis System)” manufactured by qea. Table 7 shows the resolution evaluation results. In Table 7, “◯” indicates that the resolution is 600 dpi or higher, and “X” indicates that the resolution is smaller than 600 dpi.

As can be seen from Table 7, the flow rate of Si in the raw material gas per 1 W of high-frequency power is set to 2.5 sccm / W or more and 13.3 sccm / W or less in order to suppress the peeling of the coating layer and other characteristics. The result that it should just set is obtained.

In this example, when the a-SiONB-containing layer was formed using a glow discharge decomposition apparatus, the influence of the pressure in the reaction chamber on the occurrence of film peeling and the electrical property unevenness in the electrophotographic photosensitive member was examined.

[Creation of electrophotographic photoreceptor]
The electrophotographic photoreceptor was prepared under the same conditions as in Example 1 except for the a-SiONB-containing layer. The a-SiONB-containing layer was formed under the conditions shown in Table 8 except for the pressure. The pressure was set in the range shown in Table 9.

[Presence or absence of film peeling]
The presence or absence of film peeling was examined in the same manner as in Example 1. Table 9 shows the evaluation results of the presence or absence of film peeling.

[Electrical characteristics unevenness]
The electrical property unevenness was evaluated in the same manner as in Example 4 using a potential measuring device (manufactured by Kyocera Corporation). The evaluation results of the electrical characteristic unevenness are shown in Table 9.

As can be seen from Table 9, the pressure may be set to 40 Pa or more and 146.7 Pa or less, and the pressure may be set to 53.3 Pa or more and 133.3 Pa or less in order to suppress the peeling of the coating layer and the occurrence of uneven electrical characteristics. If set, the occurrence of film peeling can be suppressed more favorably.

In this example, when the a-SiONB-containing layer was formed using a glow discharge decomposition apparatus, the influence of the film formation time on the occurrence of film peeling and the electric characteristic unevenness in the electrophotographic photosensitive member was examined.

[Creation of electrophotographic photoreceptor]
The electrophotographic photoreceptor was prepared under the same conditions as in Example 1 except for the a-SiONB-containing layer. The a-SiONB-containing layer was formed under the conditions shown in Table 10 except for the film formation time. The film formation time was set in the range shown in Table 11.

[Presence or absence of film peeling]
The presence or absence of film peeling was examined in the same manner as in Example 1. Table 11 shows the evaluation results of the presence or absence of film peeling.

As can be seen from Table 11, in order to suppress the peeling of the coating layer and the occurrence of uneven electrical characteristics, the film formation time may be set to 3 minutes to 44 minutes, and the film formation time is 4 minutes to 40 minutes. If it is set to less than or equal to minutes, the occurrence of film peeling can be suppressed more favorably.

On the other hand, the thickness of the a-SiONB-containing layer when film peeling is appropriately suppressed in this example is 0.15 μm or more, more preferably 0.20 μm or more. Accordingly, it can be seen from the results of this example that the thickness of the a-SiONB-containing layer should be set to 0.15 μm or more, more preferably 0.20 μm or more, in order to suppress film peeling.

Claims

An electrophotographic photosensitive member comprising a conductive substrate and a coating layer covering the conductive substrate,
The covering layer includes a photosensitive layer, a pressure-resistant layer positioned between the conductive substrate and the photosensitive layer, and an a-SiONB-containing layer positioned between the conductive substrate and the pressure-resistant layer. An electrophotographic photoreceptor comprising
2. The electrophotographic photosensitive member according to claim 1, wherein the content of N element in the a-SiONB-containing layer is 0.630% or more when the content of Si element is 100 based on the number of atoms.
2. The electrophotographic photosensitive member according to claim 1, wherein the content of O element in the a-SiONB-containing layer is 1.05% or more when the content of Si element is 100, based on the number of atoms.
2. The electrophotographic photoreceptor according to claim 1, wherein the content of B element in the a-SiONB-containing layer is 200 ppm or more and 1000 ppm or less when the content of Si element is 100.
The electrophotographic photosensitive member according to claim 1, wherein the a-SiONB-containing layer has a thickness of 0.15 µm or more and 1.05 µm or less.
The electrophotographic photosensitive member according to claim 1, wherein the pressure-resistant layer contains a-SiN.
The electrophotographic photosensitive member according to claim 6, wherein the ratio of the number of nitrogen atoms to the total number of nitrogen atoms and silicon atoms in the pressure-resistant layer is 0.01 or more and 0.55 or less.
The electrophotographic photosensitive member according to claim 1, wherein the pressure-resistant layer has a thickness of 0.5 μm to 1.2 μm.
The electrophotographic photosensitive member according to claim 1, wherein the photosensitive layer has a thickness of 15 μm or more and 90 μm or less.
An image forming apparatus comprising the electrophotographic photosensitive member according to claim 1.
A first step of forming an a-SiONB-containing layer on a conductive substrate, a second step of forming a pressure-resistant layer on the a-SiONB-containing layer, and a third step of forming a photosensitive layer on the pressure-resistant layer. A method for producing an electrophotographic photoreceptor comprising
The first step is performed by supplying a raw material gas to a reaction chamber containing a conductive substrate and supplying high-frequency power to the conductive substrate; and
The method for producing an electrophotographic photosensitive member, wherein the high-frequency power is set to 50 W or more and 400 W or less.
In the first step, a gas containing a Si compound is used as the source gas, and the flow rate of the Si compound per 1 W of the high-frequency power is set to 2.5 sccm or more and 13.3 sccm or less. A process for producing the electrophotographic photosensitive member according to 1.
The method for producing an electrophotographic photosensitive member according to claim 11, wherein, in the first step, the pressure in the reaction chamber is set to 40.0 Pa or more and 146.7 Pa or less.