JP2008216306A - Method for polishing protrusion of electrophotographic photoreceptor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for polishing an electrophotographic photoreceptor, by which the surface of the electrophotographic photoreceptor is polished, without producing a polishing flaw due to polishing processing, so that image defects can be minimized. <P>SOLUTION: In the method for polishing protrusions to remove the protrusion tops of the surface of an electrophotographic photoreceptor including a photoconductive layer comprising at least amorphous silicon; the electrophotographic photoreceptor is held and rotated; a polishing tape is fed to polish protrusions; while the polishing tape is brought into pressure-contact with the surface of the photoreceptor by a cylindrical pressing member, where the surface of the cylindrical pressing member is made spiral, so that the surface the photoreceptor and the polishing tape are brought into contact with each other; and chips produced at an early stage of polishing do not reach a place polishing processing is carried out. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  High sensitivity and SN ratio [photocurrent (IP) / dark current (Id)] as a material to form a photoconductive layer in solid-state imaging devices or electrophotographic photoreceptors for electrophotography and document readers in the field of image formation It has high absorption spectral characteristics that match the spectral characteristics of the electromagnetic wave to be irradiated, has fast photoresponsiveness, has a desired dark resistance value, is non-polluting to the human body during use, and in solid-state imaging devices However, characteristics such as the ability to easily process afterimages within a predetermined time are required.

  Particularly in the case of an electrophotographic photoreceptor used in an office as an office machine, the above-mentioned pollution-free property is an important point.

  A material that has been attracting attention based on this viewpoint is amorphous silicon in which dangling bonds are modified with monovalent elements such as hydrogen and halogen atoms (hereinafter referred to as “a-Si”). Applications to electrophotographic photoreceptors for electrophotography have been made.

  Conventionally, as a formation method for forming an electrophotographic photosensitive member made of a-Si on a conductive substrate, a sputtering method, a method of decomposing a source gas by heat (thermal CVD method), a method of decomposing a source gas by light ( There are many known methods such as a photo-CVD method and a method of decomposing a source gas by plasma (plasma CVD method). Among them, the plasma CVD method, that is, a method of forming a deposited film on a conductive substrate by decomposing a raw material gas by glow discharge such as direct current, high frequency, or microwave, is currently put into practical use, such as a method for forming an electrophotographic photosensitive member. Very advanced. As a layer structure of such a deposited film, a so-called surface layer having a blocking ability on the surface side in addition to a conventional electrophotographic photosensitive member based on a-Si and appropriately adding a modifying element. In addition, a configuration in which an upper blocking layer is stacked has also been proposed (for example, Patent Document 1). In Patent Document 1, a photoconductor is provided in which an intermediate layer (upper blocking layer) containing atoms that reduce the carbon atom content from the surface layer and control conductivity is provided between the photoconductive layer and the surface layer. It is disclosed.

Further, the a-Si film has a property that when dust of several μm order adheres to the substrate surface, abnormal growth, that is, so-called “protrusions” grow with the dust as a nucleus during film formation. This protrusion causes a defect on the image. In order to prevent this image defect, a technique has also been proposed in which the top of the protrusion on the surface of the photoreceptor after film formation is flattened by polishing (for example, Patent Document 2). In Patent Document 2, the electrophotographic photosensitive member is held and rotated, and the polishing tape is fed while the polishing tape wound around the elastic roller and the surface of the photosensitive member are brought into pressure contact with each other. A post-processing method for performing planarization polishing is disclosed.
Japanese Patent Laid-Open No. 08-15882 JP 2001-318480 A

  Such a conventional method for producing an electrophotographic photosensitive member makes it possible to obtain an electrophotographic photosensitive member having practical characteristics and uniformity to some extent.

  However, in these conventional methods for producing an electrophotographic photosensitive member, for example, an electrophotographic photosensitive member having a large area and a relatively thick deposited film requires uniform film quality, optical and electrical characteristics. The problem to be solved remains that it is difficult to obtain a deposited film with high image yield in an image formation by an electrophotographic process with few image defects.

  In particular, the a-Si film has the property that when dust of the order of several μm adheres to the surface of the substrate, abnormal growth, that is, so-called “protrusions” grow using the dust as a nucleus during film formation. Protrusions have a shape that is a reversal of the conical shape starting from dust, and there are many localized levels at the interface between the normal deposition part and the protrusion part, so the resistance decreases, and the charged charge passes through the interface through the substrate. It has the property of falling out to the side. For this reason, the part with the protrusion appears as a white point in the solid black image on the image (in the case of reversal development, it appears as a black point in the solid white image). These so-called “pochi” image defects are becoming more stringent every year, and depending on the size, they may be treated as defective even if they are present on several A3 sheets. Furthermore, the standard becomes stricter, and even if one is present on A3 paper, it may be defective. Since these protrusions start from dust, the substrate to be used is precisely cleaned before film formation, and all the steps to be installed in the film formation apparatus are performed in a clean room or under vacuum. In this way, efforts have been made to reduce the amount of dust adhering to the substrate before the start of film formation, and the effect has been improved.

  However, the cause of the protrusion is not only the dust adhering to the substrate. That is, when an a-Si photosensitive member is manufactured, the required film thickness is very large, from several μm to several tens of μm, and therefore the film formation time ranges from several hours to several tens of hours. During this time, the a-Si film is deposited not only on the substrate but also on the walls of the film forming furnace and the structures in the film forming furnace. Since these furnace walls and structures do not have a controlled surface like the substrate, the adhesion is weak in some cases, and film peeling may occur during film formation over a long period of time. If even a slight peeling occurs during the film formation, it becomes dust and adheres to the surface of the photoconductor being deposited, and this causes the abnormal growth of protrusions. Therefore, in order to maintain a high yield, polishing is performed to flatten abnormally grown protrusions, and an upper blocking layer having a blocking ability against charged charges is laminated so as to cover the flattened protrusions. In order to prevent the phenomenon that the charged charges slip through the interface between the normal part and the protruding part, the effect has been improved.

However, in order to perform the polishing process, a silicon carbide layer having a dynamic hardness of about 1000 kgf / mm ² must be laminated as a layer to be polished in order to suppress generation of polishing flaws due to the polishing process. Further, simply laminating a silicon carbide layer having a dynamic hardness of about 1000 kgf / mm ² on the photoconductive layer may cause deterioration in charging performance. Therefore, in order to suppress the occurrence of polishing scratches due to polishing processing and prevent deterioration of charging performance, a silicon carbide layer having a blocking ability against charged charges and a silicon carbide layer having a dynamic hardness of about 1000 kgf / mm ² are used. It was necessary to laminate.

  The silicon carbide layer increases the resistance value of the layer itself by adjusting the ratio of silicon and carbon contained in the layer, or selectively contains dopants such as Group 13 elements of the periodic table and Group 15 elements of the periodic table Thus, by providing rectification, a layer having a blocking ability against charged charges can be obtained. However, in the range of the ratio of silicon and carbon that functions as a layer having a blocking ability against charged charges, the dynamic hardness is relatively low, and polishing scratches may occur on the photoreceptor in the conventional polishing process. .

Therefore, if it is possible to find an effective polishing method that does not damage the polishing process even if the silicon carbide layer has a relatively low dynamic hardness, it is necessary to stack a silicon carbide layer having a dynamic hardness of about 1000 kgf / mm ^2. The advantage of eliminating

  The dynamic hardness in the present invention is a value measured using a dynamic hardness meter (model number DUH-201) manufactured by Shimadzu Corporation.

  In order to promote removal of polishing residues and prevent damage to the photosensitive member, the polishing residue is generally left between the polishing tape and the photosensitive member. In order to prevent this, the surface moving speed of the polishing tape is changed and the tape is fed quickly.

  However, when a relatively soft silicon carbide layer is a layer to be polished, it has been confirmed that even if the above polishing method is used, the surface of the photoreceptor is scratched. This occurs at the initial stage of polishing, with a size of several μm to several tens of μm, which is very large compared to the intermediate period of polishing or immediately before the end, and the normal surface of the photoconductor and the polishing tape are in contact with each other. Therefore, it is considered that a large pressure is locally applied only to a portion where a lump is present between the photoconductor and the polishing tape, and the normal surface of the photoconductor is damaged.

  For this reason, when the layer to be polished is a relatively soft silicon carbide layer, the top of the protrusion is polished and flattened, and the normal surface of the photoconductor is not scratched. The present inventors have found that it is important to prevent a very large lump of several μm to several tens of μm from reaching the place where the normal surface of the photoconductor is in contact with the polishing tape. I found it.

  Based on such insight, the method for polishing an electrophotographic photosensitive member in the present invention for achieving the above-described object removes the projection tops on the surface of the electrophotographic photosensitive member including at least a photoelectric conducting layer made of amorphous silicon. In the projection polishing method, a cylinder when polishing the projection by holding and rotating the electrophotographic photosensitive member and feeding the polishing tape while pressing the polishing tape against the surface of the photosensitive member with a cylindrical pressing member. The surface of the shaped pressing member has a spiral shape.

  As described in detail above, according to the method for polishing an electrophotographic photosensitive member of the present invention, since the surface of the pressing member that presses and contacts the polishing tape with the surface of the photosensitive member has a spiral shape, Since the generated clumps can be removed from the contact area between the photoconductor and polishing tape, the top of the projections can be flattened without damaging the photoconductor even if it has a relatively low dynamic hardness. It was achieved that it could be polished.

  Hereinafter, the present invention will be described in detail with reference to the drawings as necessary.

<< Surface polishing apparatus according to the present invention >>
FIG. 1 is a schematic diagram showing an example of a polishing apparatus according to the present invention.

  The photoconductor (100) is held by the elastic support mechanism (120), and is fixed at a predetermined position in the moving range (141) on the moving stage (140). The elastic support mechanism (120) is specifically a pneumatic holder. For example, a pneumatic holder (trade name: air pick, model number: PO45TCA * 820) manufactured by Bridgestone Corporation can be used. The polishing tape (131) is held by the feed roller (132), fed out from there, pressed against the photoconductor (100) by the pressing member (130), and further, the quantitative take-up roller (134) and the capstan roller ( 135), taken up at a fixed speed, and taken up by a take-up roller (133). At this time, the polishing tape (231) may be passed through a tape guide roller (236) as shown in FIG. The pressing member (130) is pressed against the photoconductor (100) by the pressing mechanism (137).

  The photosensitive member (100) is rotated, and the polishing process is performed by feeding the polishing tape (131) at a speed different from the linear speed. At this time, when the linear velocity of the photoconductor (100) is in the range of 10 to 40 cm / sec and the feed speed of the polishing tape is in the range of 1 to 20 cm / min, the relationship between the consumption of the polishing tape, the polishing time, and the polishing scratches To be determined comprehensively.

  Further, the thickness of the polishing tape (131) is appropriately determined depending on the durability of the polishing tape itself, the followability to the spiral shape of the pressing member surface of the present invention, and the material of the pressing member. If the thickness of the polishing tape is thin, the followability to the spiral shape of the pressing member surface will increase, but the durability of the polishing tape itself will decrease, or polishing scratches will occur if a metal roller is used for the pressing member There is a case. Specifically, it is set in the range of 5 to 150 μm, more preferably in the range of 20 to 80 μm. In the present invention, the followability of the polishing tape to the spiral shape of the pressing member surface indicates how much the polishing tape reproduces the shape of the pressing member surface, and FIG. Is a low example, and FIG. 10B is a high follow-up example.

  Also, due to the frictional resistance with the polishing tape (131), the rotation with the photoconductor (100) is likely to occur, so the polishing tape (131) is sent in the direction opposite to the rotation direction of the photoconductor (100), Polishing is desirable. In this case, the take-up roller (133), the quantitative take-up roller (134) and the capstan roller (135) adjust the speed of the polishing tape (131), and the feed roller (132) adjusts the tape tension. On the other hand, a polishing process in which the rotation direction of the photosensitive member (100) and the feeding direction of the polishing tape (131) are the same direction is also effective by appropriately maintaining the pressure and the tape tension. The tape tension is appropriately set in an optimal range in consideration of the rotation around the photoreceptor (100) and the followability to the spiral shape of the surface of the pressing member of the present invention.

  Also, at the initial stage of polishing, in order to prevent polishing scratches due to polishing residues, polishing may be performed by sending the polishing tape (131) at a speed larger than the rotational linear speed of the photoconductor (100). The polishing process is performed by feeding the polishing tape (131) at a speed smaller than the speed.

  Support of the photoconductor (100) is achieved by inserting a compressed pneumatic holder into the cavity of the photoconductor substrate, and then feeding air of 100 kPa to 1000 kPa. At the time of polishing, the entire unit is rotated and the photosensitive member (100) is rotated. As a guide, a guide flange having a loose fit, rich lubricity, and elasticity may be provided. The material of the guide flange is preferably a resin such as polyacetal (POM), polyamide (PA), or polycarbonate (PC). The support of the photoconductor (100) is controlled by the air pressure of the pneumatic holder, and minute vibrations such as chatter and rush shock are absorbed and relaxed by the pneumatic holder.

  The pressing member (130) of the present invention may be made of a material such as neoprene rubber or silicon rubber. The JIS rubber hardness (JIS K 6253-1997) at this time is preferably in the range of 20 to 80, more preferably in the range of 30 to 40. Further, the shape of the pressing member is preferably such that, in the longitudinal direction, the diameter of the central part is slightly larger than the diameters of both end parts, for example, the diameter difference between the two is 0.0 to 0.6 mm, more preferably 0.2 to 0.4 mm. A shape that falls within this range is preferred. Further, the pressing member (130) may be a metal roller made of a material such as stainless steel, iron, copper, brass or aluminum as long as the surface has a spiral shape.

  The pressure of the pressing member (130) is comprehensively determined in the range of 9.8 to 980 kPa from the relationship between the fine surface shape of the photoreceptor surface to be polished, the polishing time and the polishing scratches. In order to control the pressurization, it is also effective to provide a cylinder in the support portion of the pressing member (130) and control it by air pressure or hydraulic pressure.

  In the present invention, the surface of the cylindrical pressing member (130) has a spiral shape as shown in FIG. 5 (a). By adopting such a spiral shape, a concave portion and a convex portion are formed at the contact portion between the photoconductor (100) as the object to be processed and the polishing tape (131). And the grinding | polishing process of the top part of a processus | protrusion (611) is performed in a convex part. Since the lump generated at that time enters the recess, it can be satisfactorily polished without reaching the contact portion between the photoconductor (100) and the polishing tape (131).

  In addition, the spiral cross-sectional shape of the surface of the pressing member (130) may be a shape in which a concave portion and a convex portion can be formed at the contact portion between the photosensitive member (100) and the polishing tape (131), which is the object to be processed. Specifically, a shape as shown in FIGS. 5B to 5E is an example.

  Further, it is more preferable to perform the polishing process while heating the polishing tape (131) in order to suppress the generation of polishing flaws. Specifically, as shown in FIG. 3 (a), a heating member (338) such as a halogen lamp is provided inside the pressing member (330), and the pressing member (330) is heated to polish the polishing tape (331). As shown in FIG. 3 (b), a heating body (338) such as a halogen lamp is provided upstream of the contact portion between the photosensitive body (300) to be processed and the polishing tape (331). And a method of heating the polishing tape (331) may be used. Thus, by heating the polishing tape (331), the polishing tape (331) is softened, the followability to the spiral shape on the surface of the pressing member (330) is increased, and the generation of polishing flaws can be further suppressed. Further, the surface temperature of the pressing member (330) is the optimum temperature at which the polishing tape (331) can always be softened by the heating body (338), the temperature detection element (not shown), and the control means (not shown). Maintained.

  In addition, it is more preferable to perform polishing while relatively rotating the photosensitive member and the polishing tape in a direction perpendicular to the rotation direction of the photosensitive member in order to suppress polishing unevenness. Specifically, as shown in FIG. 4, by providing a reciprocating mechanism (450) in the elastic support mechanism (420), the photoreceptor (400) and the polishing tape (431) can rotate the photoreceptor (400). Relative movement can be made relatively in a direction perpendicular to the direction. Alternatively, the reciprocating mechanism (450) can be provided in the pressing member (430) to perform the alternate motion in the same manner. The relationship between the speed in the rotation direction of the photoconductor and the speed in the direction orthogonal to the rotation direction of the photoconductor is appropriately determined from the viewpoint of polishing scratches and polishing unevenness.

<< a-Si photoconductor according to the present invention >>
FIG. 9 shows an example of an electrophotographic photoreceptor according to the present invention.

  The electrophotographic photosensitive member of the present invention includes, as a first step, a substrate (901) made of a conductive material such as Al or stainless steel in a vacuum-tight film forming furnace equipped with an exhaust unit and a source gas supply unit. And at least the source gas is decomposed by high frequency power, and a photoconductive layer (906) made of at least a non-single crystal material on the substrate (901) and a silicon carbide layer made of a non-single crystal material containing at least carbon and silicon ( 913) as the first layer (902), and as the second step, the step of removing the cylindrical substrate on which the first layer (902) is laminated from the film-forming furnace once, and the third step as the first step The polishing step of the present invention for processing the surface of the silicon carbide layer (913) on the cylindrical substrate on which the layer (902) is laminated, and the cylindrical substrate on which the first layer (902) is laminated as the fourth step Is again installed in the film-forming furnace, at least the source gas is decomposed by high-frequency power, and the first A second layer (903) made of a non-single crystal material is deposited on the layer (902).

  By forming the film in this way, the second layer (903) can be laminated so as to cover the abnormal growth portion (911) generated from the first layer (902), even if the abnormal growth portion Even if (911) is present, it does not appear in the image and it is possible to maintain good image quality.

  Further, by laminating the silicon carbide layer (913) on the outermost surface of the first layer (902) in the first step, the film of the second layer and the first layer laminated in the fourth step Adhesion is improved and the latitude for film peeling can be widened. In addition, the silicon carbide layer (913) can selectively contain dopants such as Group 13 elements of the periodic table and Group 15 elements of the periodic table, and can also have a blocking ability against charged charges by providing rectification. It is also possible to maintain the charging performance.

  In the present invention, the first layer (902) includes the photoconductive layer (906), and a-Si is used as the material of the photoconductive layer (906). The first layer (902) may be further provided with a lower blocking layer (905) if necessary.

  Further, in the present invention, the second blocking layer (903) may include an upper blocking layer (908), the material of the upper blocking layer (908) is based on a-Si, if necessary carbon, A layer containing nitrogen, boron and oxygen is used.

  In the upper blocking layer (908), it is desirable from the viewpoint of improving the charging performance to selectively contain a dopant such as Group 13 element of the periodic table, Group 15 element of the periodic table, and to have a rectifying property, It is also possible to control the charging polarity such as positive charging and negative charging.

Further, the second layer (903) can be laminated with a surface layer (904) having a dynamic hardness of at least 1000 kgf / mm ² made of at least a non-single crystal material, thereby improving the abrasion resistance of the electrophotographic photosensitive member. Scratch resistance can be improved.

  The second layer (903) may be provided with an a-Si intermediate layer (907) below the upper blocking layer (908) as necessary. As the intermediate layer (907), a layer having the same composition as that of the silicon carbide layer (913) is used for the purpose of improving the adhesion between the first layer (902) and the second layer (903).

<< Shape and Material of Substrate According to the Present Invention >>
The shape of the substrate (901) shown in FIG. 9 may be as desired according to the driving method of the electrophotographic photosensitive member.

  For example, it can be a cylindrical or plate-like endless belt with a smooth surface or an uneven surface, and its thickness is appropriately determined so that the desired electrophotographic photoreceptor can be formed. Is required, it can be made as thin as possible within a range where the function as a substrate can be sufficiently exhibited. However, in terms of manufacturing and handling, the substrate is usually 0.5 mm or more for the cylindrical shape and 10 μm or more for the plate-like endless belt shape in terms of mechanical strength.

  As the base material, conductive materials such as Al and stainless steel are generally used. For example, at least a light receiving layer is formed on the following conductive materials on various plastics, glass, ceramics, etc., especially those that are not conductive. A material imparted with conductivity, for example, by vapor deposition on the surface to be used can be used.

  In addition to the above, examples of the conductive material include metals such as Cr, Mo, Au, In, Nb, Te, V, Ti, Pt, Pd, and Fe, and alloys thereof.

  Examples of the plastic include films or sheets of polyester, polyethylene, polycarbonate, cellulose acetate, polypropylene, polyvinyl chloride, polystyrene, polyamide, and the like.

<< First Layer According to the Present Invention >>
As the first layer (902) shown in FIG. 9, in the present invention, an amorphous material (“a-Si: (H, X)”) containing silicon atoms as a base and further containing hydrogen atoms and / or halogen atoms is used. (Abbreviated).

The photoconductive layer (906) can be formed by a plasma CVD method, a sputtering method, an ion plating method, or the like, but a film formed by using the plasma CVD method is particularly preferable because a high-quality film can be obtained. By using silicon hydride (silanes) in a gas state such as SiH ₄ , Si ₂ H ₆ , Si ₃ H ₈ , Si ₄ H ₁₀ or the like as a raw material gas as a raw material gas, Can be created. Further, SiH ₄ and Si ₂ H ₆ are preferable from the viewpoint of easy handling at the time of layer preparation and good Si supply efficiency.

  At this time, the temperature of the substrate is preferably maintained at a temperature of about 200 ° C. to 450 ° C., more preferably about 250 ° C. to 350 ° C. in view of characteristics. This is for accelerating the surface reaction on the substrate surface and sufficiently relaxing the structure.

It is also preferable to improve the characteristics by mixing these gases with a desired amount of a gas containing H ₂ or a halogen atom to form a layer. Effective examples of the source gas for supplying the halogen atoms include interhalogen compounds such as fluorine gas (F ₂ ), BrF, ClF, ClF ₃ , BrF ₃ , BrF ₅ , IF ₅ and IF ₇ . Specific examples of silicon compounds containing halogen atoms, so-called silane derivatives substituted with halogen atoms, include silicon fluorides such as SiF ₄ and Si ₂ F ₆ .

Further, these source gases for supplying silicon may be diluted with a gas such as H ₂ , He, Ar, Ne or the like as necessary.

  The layer thickness of the photoconductive layer (906) is not particularly limited, but about 15 to 50 μm is appropriate in consideration of manufacturing costs.

The silicon carbide layer (913) can be formed by the plasma CVD method, the sputtering method, the ion plating method, etc., like the photoconductive layer (906), but the film formed by using the plasma CVD method is particularly high quality. It is preferable because a film of Si source as a raw material is a gas state or gasifiable silicon hydride (silanes) such as SiH ₄ , Si ₂ H ₆ , Si ₃ H ₈ , Si ₄ H _10, etc. SiH ₄ and Si ₂ H ₆ are preferable from the viewpoints of easy handling and good Si supply efficiency. The C supply source can be prepared by using CH ₄ , C ₂ H ₄ as a raw material gas and decomposing with high frequency power. The carbon content relative to the sum of carbon and silicon is 30% or more and 50% or less.

  Further, the silicon carbide layer (913) may be an upper blocking layer (913) having a blocking ability against charged charges by selectively containing a dopant such as Group 13 element of the periodic table and Group 15 element of the periodic table. it can. The upper blocking layer (913) has a function of blocking electric charge from being injected from the surface side to the first layer (902) side when the electrophotographic photosensitive member is subjected to charging treatment with a constant polarity on its free surface. It has a so-called polarity dependency that does not exhibit such a function when it is subjected to a charging process with a reverse polarity. In order to provide such a function, the upper blocking layer (913) needs to appropriately contain an atom for controlling conductivity. As the atoms used for such purposes, in the present invention, a group 13 atom of the periodic table or a group 15 atom of the periodic table can be used. Specific examples of such group 13 atoms in the periodic table include boron (B), aluminum (Al), gallium (Ga), indium (In), thallium (Tl), etc., especially boron (B). Is preferred. Specific examples of Group 15 atoms in the periodic table include phosphorus (P), arsenic (As), antimony (Sb), and bismuth (Bi). Phosphorus (P) is particularly preferred.

  The required content of the atoms for controlling the conductivity contained in the upper blocking layer (913) is not unambiguous depending on the composition of the upper blocking layer (913) and the manufacturing method. On the other hand, it is preferably 100 atomic ppm or more and 30000 atomic ppm or less.

  The atoms controlling the conductivity contained in the upper blocking layer (913) may be uniformly distributed in the upper blocking layer (913) or may be unevenly distributed in the layer thickness direction. It may contain. However, in any case, in the in-plane direction parallel to the surface of the substrate, it is necessary to uniformly contain the material in a uniform distribution from the viewpoint of uniform characteristics in the in-plane direction.

  Further, the first layer (902) may have a plurality of layers to improve the characteristics. For example, by arranging a layer having a narrower band gap on the surface side and a layer having a wider band gap on the substrate side, the photosensitivity and charging characteristics can be improved at the same time. In particular, for a light source having a relatively long wavelength and almost no variation in wavelength, such as a semiconductor laser, an epoch-making effect appears by such a device structure.

  For example, the lower blocking layer (905) provided as necessary is generally based on a-Si: (H, X) and contains dopants such as Group 13 elements of the periodic table and Group 15 elements of the periodic table. By controlling the conductivity type, it is possible to prevent the carrier from being injected from the substrate. In this case, if necessary, the stress can be adjusted by containing at least one element selected from C, N, and O, and the function of improving the adhesion of the photoconductive layer (906) can be provided. .

The listed elements are used as Group 13 elements and Group 15 elements of the periodic table used as dopants for the lower blocking layer (905). Further, as a raw material for introducing Group 13 atoms of the periodic table, specifically for introducing boron atoms, B ₂ H ₆ , B ₄ H ₁₀ , B ₅ H ₉ , B ₅ H ₁₁ , B ₆ H ₁₀ , Examples thereof include boron hydrides such as B6H ₁₂ and B6H ₁₄ , and boron halides such as BF ₃ , BCl ₃ and BBr ₃ . In addition, AlCl ₃ , GaCl ₃ , Ga (CH ₃ ) ₃ , InCl ₃ , TlCl _{3 and the} like can also be mentioned. Among these, B ₂ H ₆ is one of the preferred raw materials from the viewpoint of handling.

As a raw material for introducing Group 15 atoms of the periodic table, phosphorus hydrides such as PH ₃ , P ₂ H ₄ , PF ₃ , PF ₅ , PCl ₃ , PCl ₅ are used effectively for introducing phosphorus atoms. , Phosphorus halides such as PBr ₃ and PI ₃ , and PH4I. In addition, AsH ₃ , AsF ₃ , AsCl ₃ , AsBr ₃ , AsF ₅ , SbH ₃ , SbF ₃ , SbF ₅ , SbCl ₃ , SbCl ₅ , BiH ₃ , BiCl ₃ , BiBr ₃ etc. are introduced in Group 15 atoms of the periodic table As an effective starting material for use.

The content of dopant atoms is preferably 1 × 10 ⁻² to 1 × 10 ⁴ atomic ppm, more preferably 5 × 10 ^{−2 to} 5 × 10 ³ atomic ppm, and most preferably 1 × 10 ⁻¹ to 1 × What is ¹⁰³ atomic ppm is desirable.

  In addition, any frequency can be used as the discharge frequency used in the plasma CVD method when laminating the first layer (902). A high frequency of 50 MHz or more and 450 MHz or less called a band can be suitably used.

  It is also meaningful to inspect the appearance and evaluate the characteristics of the photoreceptor as needed when the photoreceptor is removed from the film forming furnace. By performing the inspection at this point, it is possible to omit the subsequent steps for the poor quality electrophotographic photosensitive member, and the overall cost can be reduced.

  Furthermore, it is desirable to clean the electrophotographic photosensitive member before installing it again in the film forming furnace in order to improve the adhesion of the second layer (903) described later and reduce dust adhesion. As a specific cleaning method, a method of wiping the surface with a clean cloth or paper, or preferably a precision cleaning by organic cleaning or water cleaning is desirable. In particular, in view of environmental considerations in recent years, water washing with a water washing apparatus described later is more preferable.

<< Second Layer According to the Present Invention >>
The second layer (903) according to the present invention shown in FIG. 9 is laminated after the first layer (902) is formed, once the discharge is stopped, and polishing is performed.

  Further, the second layer (903) of the present invention may include an upper blocking layer (908). The upper blocking layer (908) can be made of any material as long as it is an a-Si-based material, but is preferably composed of the same material as the layer to be polished (913) laminated in the first layer. . The upper blocking layer (908) prevents the charge from being injected from the surface side to the first layer (902) side when the electrophotographic photosensitive member is subjected to charging treatment with a certain polarity on its free surface. It has a so-called polarity dependency that has a function and does not exhibit such a function when it is subjected to a charge treatment with a reverse polarity. In order to provide such a function, the upper blocking layer (908) needs to appropriately contain an atom for controlling conductivity. As the atoms used for such purposes, in the present invention, a group 13 atom of the periodic table or a group 15 atom of the periodic table can be used. Specific examples of such group 13 atoms in the periodic table include boron (B), aluminum (Al), gallium (Ga), indium (In), and thallium (Tl). Boron is particularly preferable. is there. Specific examples of Group 15 atoms in the periodic table include phosphorus (P), arsenic (As), antimony (Sb), and bismuth (Bi). Phosphorus (P) is particularly preferred.

  The necessary content of the atoms for controlling the conductivity contained in the upper blocking layer (908) cannot be generally determined depending on the composition of the upper blocking layer (908) and the manufacturing method. On the other hand, it is preferably 100 atomic ppm or more and 30000 atomic ppm or less.

  The atoms that control the conductivity contained in the upper blocking layer (908) may be uniformly distributed in the upper blocking layer (908) or distributed unevenly in the layer thickness direction. It may contain. However, in any case, in the in-plane direction parallel to the surface of the substrate, it is necessary to uniformly contain the material in a uniform distribution from the viewpoint of uniform characteristics in the in-plane direction.

The film thickness of the upper blocking layer (908) is adjusted to a film thickness that can effectively prevent image defects due to the abnormally grown portion (911). There are various sizes when the abnormally grown portion (911) is viewed from the surface side, but the larger the diameter, the greater the degree of charge injection and the more likely it is to appear in an image. Therefore, it is effective to increase the thickness of the upper blocking layer (908) as the protrusion becomes larger. Specifically it is preferable that the largest of the thickness of more than 10 ^-4 times the diameter of the abnormal growth portion present on the photosensitive member (911). By setting the thickness within this range, it is possible to effectively prevent charges from slipping out from the abnormally grown portion (911). In addition, it is desirable that the upper limit of the film thickness is 1 μm or less from the viewpoint of minimizing sensitivity reduction.

  In order to form the upper blocking layer (908), it is necessary to appropriately set the pressure in the reaction vessel and the heating temperature (Ts) of the substrate (901) as desired.

The optimum range of the pressure in the reaction vessel is appropriately selected according to the layer design, but in the normal case 1 × 10 ⁻² to 1 × 10 ³ Pa, preferably 5 × 10 ^{−2 to} 5 × 10 ² Pa, optimal Is preferably 1 × 10 ⁻¹ to 1 × 10 ² Pa.

  Further, the optimum range for the heating temperature (Ts) of the substrate (901) is appropriately selected according to the layer design, but in the usual case, it is preferably 150 to 350 ° C, more preferably 180 to 330 ° C, optimally 200. It is desirable that the temperature be ˜300 ° C.

  The second layer (903) of the present invention may be provided with an a-Si-based intermediate layer (907) below the upper blocking layer (908) as necessary.

  The intermediate layer (907) can be made of any material as long as it is an a-Si-based material, but is preferably made of the same material as the layer to be polished (913) laminated on the first layer.

In order to form the intermediate layer (907), it is necessary to appropriately set the heating temperature (Ts) of the substrate (901) and the gas pressure in the reaction vessel as desired. The optimum range for the heating temperature (Ts) of the substrate (901) is appropriately selected according to the layer design, but in the usual case, it is preferably 150 to 350 ° C, more preferably 180 to 330 ° C, and most preferably 200 to 300. Desirably, the temperature is set to ° C. Similarly, the optimum range of the pressure in the reaction vessel is appropriately selected according to the layer design, but in the usual case, 1 × 10 ⁻² to 1 × 10 ³ Pa, preferably 5 × 10 ^{−2 to} 5 × 10 ² Pa, Optimally, it is preferably 1 × 10 ⁻¹ to 1 × 10 ² Pa.

The second layer can be provided on the upper blocking layer (908) as a surface layer (909) with at least a layer made of a non-single crystal material. The surface layer (909) is characterized in that the dynamic hardness is 1000 kgf / mm ² or more, thereby improving the wear resistance and scratch resistance of the electrophotographic photosensitive member.

  In addition, the dynamic hardness was measured using a dynamic hardness meter (model number DUH-201) manufactured by Shimadzu Corporation under the same conditions as those prepared on a conductive substrate on a silicon wafer. The composition analysis was carried out using a X-ray photoelectron analyzer (model Quantum2000) manufactured by ULVAC-PHI Co., Ltd. under the same conditions as those prepared on a conductive substrate on a Corning 7059 glass substrate.

<< a-Si Photosensitive Film Forming Apparatus According to the Present Invention >>
FIG. 8 is a diagram schematically illustrating an example of a film forming apparatus for an electrophotographic photosensitive member by an RF plasma CVD method using a high-frequency power source.

  This apparatus is roughly composed of a film forming apparatus (8100), a source gas supply apparatus (8200), and an exhaust apparatus (not shown) for reducing the pressure in the film forming furnace (8110). A substrate (8112) connected to earth, a heater (8113) for heating the substrate, and a gas introduction pipe (8114) are installed in a film forming furnace (8110) in the film forming apparatus (8100), and a high-frequency matching box A high frequency power supply (8120) is connected via (8115).

The gas supply device (8200) includes SiH ₄ , H ₂ , CH ₄ , NO, B ₂ H ₆ , CF _{4 and} other raw material gas cylinders (8221 to 8225) and valves (8231 to 8235), (8241 to 8245), ( 8251 to 8255) and mass flow controllers (8211 to 8215), each gas cylinder is connected to a gas introduction pipe (8114) in a film forming furnace (8110) via a valve (8260).

  The base (8112) is connected to the ground by being placed on the conductive cradle.

  Hereinafter, an example of a procedure of a method for forming a photoreceptor using the apparatus of FIG. 8 will be described.

  A substrate (8112) is installed in the film forming furnace (8110), and the inside of the film forming furnace (8110) is evacuated by an unillustrated exhaust device (for example, a vacuum pump). Subsequently, the temperature of the substrate (8112) is controlled to a desired temperature of 200 ° C. to 450 ° C., more preferably 250 ° C. to 350 ° C., by the substrate heating heater (8113). Next, it is confirmed that the gas cylinder valve (8231 to 8235) and the film formation furnace leak valve (8117) are closed in order to flow the raw material gas for forming the photoreceptor into the film formation furnace (8110). Confirm that the inflow valve (8241-8245), outflow valve (8251-8255), auxiliary valve (8260) are open, open the main valve (8118), and the film formation furnace (8110) and gas supply piping Exhaust (8116).

  Thereafter, when the reading of the vacuum gauge (8119) reaches 0.67 mPa, the auxiliary valve (8260) and the outflow valve (8251 to 8255) are closed. Thereafter, each gas is introduced from the gas cylinder (8221 to 8225) by opening the valve (8231 to 8235), and each gas pressure is adjusted to 0.2 MPa by the pressure regulator (8261 to 8265). Next, the inflow valves (8241 to 8245) are gradually opened to introduce each gas into the mass flow controllers (8211 to 8215).

  After completing the preparation for film formation by the above procedure, first, for example, a photoconductive layer is stacked as a first layer on the substrate (8112).

  That is, when the base body (8112) has reached a desired temperature, necessary ones of the outflow valves (8251 to 8255) and the auxiliary valve (8260) are gradually opened, and the desired gas is discharged from each gas cylinder (8221 to 8225). The raw material gas is introduced into the film forming furnace (8110) through the gas introduction pipe (8114). Next, each mass flow controller (8211 to 8215) is adjusted so that each source gas has a desired flow rate. At that time, the opening of the main valve (8118) is adjusted while looking at the vacuum gauge (8119) so that the inside of the film forming furnace (8110) has a desired pressure of 133 Pa to 1330 Pa. When the internal pressure is stabilized, the high-frequency power source (8120) is set to a desired power and, for example, high-frequency power with a frequency of 1 MHz to 50 MHz, for example, 13.56 MHz, is supplied to the cathode electrode (8111) through the high-frequency matching box (8115). Causes a discharge. Each source gas introduced into the film forming furnace (8110) is decomposed by this discharge energy, and a photoconductive layer mainly composed of desired silicon atoms is laminated on the substrate (8112).

  After the formation of the desired film thickness, the supply of high-frequency power is stopped, each outflow valve (8251-8255) is closed to stop the flow of each source gas into the film formation furnace (8110), and the photoconductive layer Finish the lamination.

  Known compositions and film thicknesses of the photoconductive layer can be used. Subsequently, when the silicon carbide layer is subsequently laminated or when the lower blocking layer is laminated between the photoconductive layer and the substrate (8112), the above operation may be basically performed in advance. The point is that the substrate laminated up to the first layer in the above-described procedure is polished.

  Although washing with water or organic washing is preferably performed before the second layer is laminated, washing with water is more preferable in consideration of recent environmental concerns. The method of water washing will be described later. Thus, performing water washing before the second layer is laminated is effective for improving adhesion and reducing dust adhesion.

  Next, the polished substrate is returned to the film forming furnace, and the second layer is stacked.

  When the upper blocking layer, and if necessary, the intermediate layer and the surface layer are stacked on the second layer, the stacking of the first layer is basically followed.

<< Water cleaning apparatus according to the present invention >>
An example of the water cleaning apparatus used in the present invention is shown in FIG.

  The processing apparatus shown in FIG. 7 includes a processing unit (702) and a member-to-be-processed transport mechanism (703). The processing section (702) is composed of a processing member input stand (711), a processing member cleaning tank (721), a pure water contact tank (731), a drying tank (741), and a processing member unloading base (751). Yes. Both the washing tank (721) and the pure water contact tank (731) are provided with a temperature adjusting device (not shown) for keeping the temperature of the liquid constant. The transfer mechanism (703) includes a transfer rail (765) and a transfer arm (761). The transfer arm (761) is a moving mechanism (762) that moves on the rail (765) and a chuck that holds the base body (701). It consists of an air cylinder (764) for moving the king mechanism (763) and the chucking mechanism (763) up and down. The substrate (701) placed on the input table (711) is transferred to the cleaning tank (721) by the transfer mechanism (703). The oil and powder adhering to the surface are cleaned by ultrasonic treatment in the cleaning liquid (722) made of the surfactant aqueous solution in the cleaning tank (721). Next, the substrate (701) is transported to the pure water contact tank (731) by the transport mechanism (703), and pure water having a resistivity of 175 kΩ · m (17.5 MΩ · cm) maintained at a temperature of 25 ° C. is used as a nozzle ( 732) to 4.9MPa of pressure. The substrate (701) after the pure water contact process is moved to the drying tank (741) by the transport mechanism (703), and is dried by blowing high-temperature high-pressure air from the nozzle (742). The substrate (701) after the drying process is carried to the unloading table (751) by the transfer mechanism (703).

(Examples and Comparative Examples)
Hereinafter, the present invention will be described in detail based on examples and comparative examples.

  The following examples are examples of the best mode of the present invention, but the present invention is not limited to these examples.

Using an RF plasma CVD type a-Si photosensitive film forming apparatus shown in FIG. 8, a lower blocking layer made of at least a non-single crystal material and at least a non-single crystal under the conditions shown in Table 1 on a φ84 mm Al substrate. An electrophotographic photosensitive member was produced in which a photoconductive layer made of a crystalline material and a silicon carbide layer made of a non-single crystalline material containing at least carbon and silicon and having a dynamic hardness of 600 kgf / mm ² were laminated.

  The obtained photoconductor was installed in the electrophotographic photoconductor surface polishing apparatus shown in FIG. 1 and polished. At that time, the pressing member mounted on the electrophotographic photosensitive member surface polishing apparatus shown in FIG. 1 is made of neoprene rubber and has a spiral surface as shown in FIG. 5 (b). . The polishing conditions were as follows: Lapping tape LT-C2000 manufactured by Fuji Photo Film Co., Ltd. (abrasive: silicon carbide (SiC), particle size: 6μm, coating method: doctor blade (knife edge) coating method) Using the tape, the pressing pressure of the pressing member was set to 400 kPa, the linear velocity of the photosensitive member was set to 20 cm / sec, and the feeding speed of the polishing tape was set to 10 cm / min.

  The photoreceptor obtained by the above procedure was evaluated for polishing scratches and polishing unevenness by the following method. The results are shown in Table 2.

《Polishing wound》
A protrusion having a diameter of about 30 μm was polished to the level line (620) shown in FIG. 6, and the surface of the electrophotographic photosensitive member after polishing was observed using an optical microscope to confirm the presence or absence of polishing scratches in the normal part. . In addition, as a judgment symbol in the table, A is that there is no polishing scratch in the normal part, B is that there are 5 or less minor polishing scratches on the entire surface of the photoconductor, and C is not practically problematic. This shows that 5 or more minor polishing flaws occurred on the entire surface of the photoreceptor.

《Polishing unevenness》
First, protrusions with a diameter of about 30 μm were picked up at a total of three locations, 20 mm from the center in the longitudinal direction of the photosensitive member, and polished for 2 minutes under the respective conditions. Then, using an optical microscope, the central portion in the longitudinal direction of the photoreceptor after polishing and the three protrusions at 20 mm positions from both ends are observed, and the top of the protrusion head is observed from the level line (620) shown in FIG. Height was measured. The measurement of the height was based on the level line (620), and was 0 when the level line (620) was polished. The difference between the maximum value and the minimum value of the height of the measured protrusion top was ΔH, and the value of ΔH was compared to evaluate polishing unevenness.

  The obtained results were ranked according to the following criteria.

A ・ ・ ・ ΔH <0.5μm
B ・ ・ ・ 0.5μm ≦ ΔH ≦ 1μm

  An electrophotographic photosensitive member was produced in which only the material of the pressing member was changed using an aluminum roller in the procedure of Example 1.

  The pressing member used was a spiral surface as shown in FIG. 5B, as in Example 1.

  The photoreceptor obtained by the above procedure was evaluated in the same manner as in Example 1 for polishing scratches and uneven polishing. The results are shown in Table 2.

  In the procedure of Example 2, an electrophotographic photoreceptor surface polishing apparatus provided with a halogen lamp (338) for heating the polishing tape inside the pressing member (330) shown in FIG. An electrophotographic photosensitive member was produced by changing only what was used.

  The pressing member used was a spiral surface as shown in FIG. 5 (c).

  The photoreceptor obtained by the above procedure was evaluated in the same manner as in Example 1 for polishing scratches and uneven polishing. The results are shown in Table 2.

  In the procedure of Example 1, the halogen lamp (338) for heating the polishing tape upstream of the contact portion between the photosensitive member (300) and the polishing tape (331) shown in FIG. An electrophotographic photosensitive member was prepared, which was changed only by using an electrophotographic photosensitive member surface polishing apparatus.

  In addition, as the pressing member, one having a spiral surface as shown in FIG. 5 (d) was used.

  The photoreceptor obtained by the above procedure was evaluated in the same manner as in Example 1 for polishing scratches and uneven polishing. The results are shown in Table 2.

  4. The electrophotography in which the polishing process shown in FIG. 4 is changed only by using the electrophotographic photosensitive member surface polishing apparatus in which the reciprocating mechanism (450) is provided in the elastic support mechanism (420) shown in FIG. A photoconductor was prepared.

  The pressing member used was a spiral surface as shown in FIG. 5 (e) as in Example 1.

  The photoreceptor obtained by the above procedure was evaluated in the same manner as in Example 1 for polishing scratches and uneven polishing. The results are shown in Table 2.

(Comparative Example 1)
In the procedure of Example 1, the electrophotographic process in which the polishing process was installed in the electrophotographic photosensitive member surface polishing apparatus shown in FIG. 1 and provided with the conventional pressing member shown in FIG. A photoconductor was prepared.

  The photoreceptor obtained by the above procedure was evaluated in the same manner as in Example 1 for polishing scratches and uneven polishing. The results are shown in Table 2.

  As can be seen from Table 2, in Example 1 and Example 2 using the polishing method of the present invention, the surface of the pressing member has a spiral shape, so that even a layer to be polished having a relatively low dynamic hardness is good. The polishing process could be performed.

  Moreover, in Example 3 and Example 4 using the polishing method of the present invention, the polishing tape is softened by heating the polishing tape, and the followability of the polishing tape to the spiral shape of the pressing member surface is increased. As a result, the generation of polishing scratches was suppressed.

  Further, in Example 5 using the polishing method of the present invention, the reciprocating mechanism is provided in the elastic support mechanism that supports the photoconductor, so that the photoconductor rotates in the circumferential direction and at the same time is orthogonal to the rotation direction of the photoconductor. As a result, it was possible to make an alternate movement in the direction of polishing, and the effect of suppressing polishing unevenness was confirmed.

Schematic configuration diagram showing an example of an electrophotographic photoreceptor surface polishing apparatus according to the present invention Schematic configuration diagram showing an example of an electrophotographic photoreceptor surface polishing apparatus according to the present invention Schematic configuration diagram showing an example of an electrophotographic photoreceptor surface polishing apparatus according to the present invention Schematic configuration diagram showing an example of an electrophotographic photoreceptor surface polishing apparatus according to the present invention Schematic configuration diagram showing an example of a pressing member used in the electrophotographic photoreceptor surface polishing apparatus according to the present invention. Schematic sectional view showing the level line when polishing the protrusion Schematic sectional view of the water cleaning device used in the present invention Schematic configuration diagram showing an example of an electrophotographic photoreceptor manufacturing apparatus by RF-PCVD according to the present invention Schematic sectional view showing an example of the electrophotographic photosensitive member of the present invention The typical block diagram showing the followability of a polishing tape to the spiral shape of the pressing member surface concerning the present invention. Schematic configuration diagram showing an example of a pressing member used in a conventional electrophotographic photosensitive member surface polishing apparatus

Explanation of symbols

100,200,300,400 substrate (photoconductor)
120,220,320,420 Elastic support mechanism
130,230,330,430 Pressing member
131,231,331,431 Abrasive tape
132,232,332,432 Feed roller
133,233,333,433 Winding roller
134,234,334,434 Fixed take-up roller
135,235,335,435 Capstan Roller
236 Tape guide roller
137,237,337,437 Pressurization mechanism
338,438 Heating body
140,240,340,440 Moving stage
141,241,341,441 Moving range
450 Reciprocating mechanism
511,1111 Pressing member
512,1112 Core
601 Conductive substrate
602 photoconductive layer
603 Silicon carbide layer (upper blocking layer, polished layer)
604 1st layer
610 dust
611 Abnormal growth (protrusion)
612 Boundary between abnormally grown part (protrusion) and normal laminated part
620 Level line
701 Substrate having a conductive surface
702 processor
703 Processed material transfer mechanism
711 Material input table
721 Cleaning tank for processed material
722 Cleaning solution
731 Pure water contact tank
732,742 nozzles
741 Drying tank
751 Unloading base for processed material
761 Transfer arm
762 Movement mechanism
763 Chucking mechanism
764 Air cylinder
765 Transport rail
8100 Deposition system
8110 reactor
8111 Cathode electrode
8112 Conductive substrate
8113 Heating heater
8114 Gas introduction pipe
8115 high frequency matching box
8116 Gas piping
8117 Leak valve
8118 Main valve
8119 Vacuum gauge
8120 high frequency power supply
5121 Insulation material
8200 Gas supply device
8211-8215 Mass Flow Controller
8221-8225 cylinder
8231-8235 Valve
8241-8245 Inlet valve
8251-8255 Outflow valve
8260 Auxiliary valve
8261-8265 Pressure regulator
901 Conductive substrate
902 First layer
903 2nd layer
905 Lower blocking layer
906 Photoconductive layer
907 Middle layer
908 Upper blocking layer
909 surface layer
910 dust
911 Abnormal growth (protrusion)
912 Boundary between abnormally grown part (protrusion) and normal laminated part
913 Silicon carbide layer (upper blocking layer, polished layer)
1001 Abrasive tape
1002 Pressing member

Claims (3)

  In the protrusion polishing method for removing the top of the protrusion on the surface of the electrophotographic photosensitive member including at least a photoconductive layer made of amorphous silicon, the electrophotographic photosensitive member is held and rotated, and a polishing tape is attached to the photosensitive member by a cylindrical pressing member. An electrophotographic photosensitive film, wherein a protrusion is polished by feeding the polishing tape while being brought into pressure contact with the surface, wherein the surface of the cylindrical pressing member has a spiral shape. Body protrusion polishing method.   2. The method for polishing a protrusion on an electrophotographic photosensitive member according to claim 1, wherein the top of the protrusion on the surface of the photosensitive member is removed while heating the polishing tape.   3. The protrusion polishing of the electrophotographic photosensitive member according to claim 1, wherein the photosensitive member and the polishing tape are relatively alternately moved in a direction perpendicular to a rotation direction of the photosensitive member. Method.

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