JP5298687B2 - Cylindrical extruded original tube for electrophotographic photosensitive member, method for producing the same, method for producing cylindrical substrate for electrophotographic photosensitive member, and electrophotographic photosensitive drum - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cylindrical substrate for an electrophotographic photoreceptor, which is suitable for full-color image formation with high picture quality that requires high dimensional accuracy, and which can be inexpensively manufactured, and to provide a cylindrical extruded raw pipe for the electrophotographic photoreceptor, to be used for the manufacture of the cylindrical substrate. <P>SOLUTION: The cylindrical extruded raw pipe for the electrophotographic photoreceptor is obtained by extruding an aluminum billet, wherein at least one surface selected form the inner face and the outer face of the cylindrical extruded raw pipe for the electrophotographic photoreceptor has at least one concave part linearly formed in the longitudinal direction of the raw pipe for the electrophotographic photoreceptor or at least one convex part linearly formed in the longitudinal direction of the raw pipe for the electrophotographic photoreceptor. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention is used for a method for manufacturing a cylindrical substrate for an electrophotographic photosensitive member used for an electrophotographic photosensitive drum in an image forming apparatus such as an electrophotographic copying machine, and for manufacturing the cylindrical substrate for the electrophotographic photosensitive member. The present invention relates to a cylindrical extruded original tube for an electrophotographic photosensitive member, a method for producing the same, and an electrophotographic photosensitive drum using the cylindrical substrate for the electrophotographic photosensitive member. More specifically, the present invention relates to a method of manufacturing a cylindrical substrate for an electrophotographic photosensitive member that requires high substrate dimensional accuracy and is suitable for full-color image formation.

  Conventionally, an electrophotographic photosensitive drum in an image forming apparatus such as an electrophotographic copying machine, a laser beam printer, a facsimile machine, or a printing machine has a photosensitive layer formed on the outer surface of a cylindrical substrate finished to a predetermined surface roughness. It is manufactured by When the dimensional accuracy of the cylindrical substrate is low, the photosensitive layer is uneven, and the image obtained by the image forming apparatus is defective. In particular, it is known that unevenness, color misregistration, and insufficient resolution tend to occur in full-color image formation formed by superimposing a plurality of colors, and increase the dimensional accuracy of a cylindrical substrate used in an electrophotographic photosensitive drum. It is hoped that.

  Generally, aluminum is used as a material for the cylindrical substrate for the electrophotographic photosensitive drum. As a general manufacturing method of a cylindrical substrate for an electrophotographic photosensitive member made of aluminum, an aluminum material is extruded and then drawn, and the obtained pipe is cut to a predetermined length to obtain an outer surface. Is used for cutting and finishing using a cutting tool such as a diamond bite.

  However, the cylindrical substrate for an electrophotographic photosensitive drum obtained in this way tends to be high in cost due to a large number of manufacturing steps and complicated steps. Therefore, for example, a cylindrical base body (EI pipe) in which the surface of an aluminum extruded raw pipe is finished by ironing without cutting, or a cylindrical base body (ED pipe) obtained by cold-drawing an aluminum extruded raw pipe ) And the like have been proposed (see Patent Document 1).

  Further, as a method for producing the extruded aluminum pipe, a processing method (for example, see Patent Document 2) of extruding an aluminum billet that is a cylindrical aluminum base using a porthole die is also used. However, since only an extrusion process using a porthole die cannot usually provide a thin and highly accurate cylindrical substrate, for example, as described in Patent Documents 3 and 4, an extrusion process using a porthole die is used. A cold drawing process is performed on the extruded original pipe obtained by the above process, which can be processed with higher accuracy than the extrusion process.

However, when the cross-sectional shape of the extruded raw pipe processed using the port hole die is not uniform, the deformation force at the time of extrusion is partially accumulated in the extruded raw pipe as a residual stress, and cold drawing is performed. It has been pointed out that the residual stress is released when performing the process and the dimensional accuracy of the processed part is lowered (see, for example, Patent Document 4). In the above method, a cylindrical substrate for a high-precision electrophotographic photosensitive member is used. Was not obtained.
JP 05-313394 A Japanese Patent Laid-Open No. 08-30002 JP 09-244286 A Japanese Patent Laid-Open No. 11-160901

  When using a conventional extruded original pipe, straightness of the cylindrical base after drawing, etc. due to uneven thickness and residual stress of the extruded original pipe (coincidence with the geometrically correct straight line of the linear form) Is known to decrease. In view of this, for example, a method of cold-drawing the extruded original pipe and further cutting the outer surface has been proposed (see Patent Document 4). However, in this method, since the number of steps increases and the cost increases, further improvement is desired.

  Therefore, for example, it is conceivable to improve the extruded original pipe itself, but a method for obtaining an extruded original pipe of an aluminum material with good dimensional accuracy after processing, the shape of the extruded original pipe with good dimensional accuracy after processing, etc. However, it is difficult to produce an electrophotographic photosensitive drum suitable for full-color image formation and the like that requires high dimensional accuracy at a low cost. .

  As described above, a cylindrical substrate for an electrophotographic photosensitive member that is suitable for high-quality full-color image formation that requires high dimensional accuracy and that can be manufactured at low cost, and a cylindrical extrusion for an electrophotographic photosensitive member that is used for manufacturing the cylindrical substrate. Providing the original pipe is desired.

  As a result of diligent studies by the present inventors to solve the above problems, when a cylindrical extruded raw tube for an electrophotographic photosensitive member has a concave portion or a convex portion on an outer surface or an inner surface, a general smoothness is obtained. We found that the dimensional accuracy is less likely to deteriorate due to residual stress in the subsequent process compared to a cylindrical extruded original tube for an electrophotographic photosensitive member, and this cylindrical extruded original tube for an electrophotographic photosensitive member is used. As a result, it was learned that an electrophotographic photosensitive drum can be manufactured with good dimensional accuracy and at low cost, and the present invention has been completed.

That is, the first gist of the present invention is a cylindrical extruded raw tube for an electrophotographic photosensitive member obtained by extruding an aluminum billet, and the inner surface of the cylindrical extruded raw tube for the electrophotographic photosensitive member and One or more concave portions formed linearly in the longitudinal direction of the cylindrical extruded raw tube for the electrophotographic photosensitive member on at least one surface selected from the outer surfaces, or the cylindrical extruded raw tube for the electrophotographic photosensitive member longitudinally convex portion formed linearly possess one or more, at least one of a width selected from the recess and the convex portion, the inner diameter of the electrophotographic photoreceptor is cylindrical extruded raw pipe 1 / The present invention resides in a cylindrical extruded original tube for an electrophotographic photosensitive member characterized by being 10 or more and 1/5 or less (claim 1).

  Further, at this time, a plurality of the concave portions or the convex portions are formed at equal angles on the outer surface of the cylindrical extruded original tube for the electrophotographic photosensitive member, with the central axis of the cylindrical extruded raw tube for the electrophotographic photosensitive member as the center. Preferably, they are formed at equal angles on the inner surface (claim 2).

  Further, the total number of the concave portions and the convex portions is preferably 3 or more (Claim 3), and at least one selected from the concave portions and the convex portions is a cylindrical extrusion source for the electrophotographic photosensitive member. It is preferable that the shape of the circumferential cross section of the tube is any one of a rectangle, a triangle, and a semicircle (Claim 4).

At least one selected from the depth and the height of the convex portion of or the recess, at least 1/10 of the thickness of the electrophotographic photoreceptor is cylindrical extruded raw pipe is preferably 1/4 or less (Claim 5 ).

Further, it is preferable to have one or more of the concave portions or the convex portions only on the inner surface of the cylindrical extruded raw tube for the electrophotographic photosensitive member (Claim 6 ), and it is preferable to have only one or more concave portions. (Claim 7 ).

The second gist of the present invention is a method for producing a cylindrical extruded raw tube for an electrophotographic photosensitive member from an aluminum billet by an extrusion method using a port hole die, which is selected from a bearing portion and a port hole outlet portion. At least one of the recesses formed in a straight line, or the port hole die having one or more protrusions formed in a straight line , and at least one selected from the recesses and the protrusions. The width is 1/10 or more and 1/5 or less of the inner diameter of the cylindrical extruded raw tube for an electrophotographic photosensitive member. Item 8 ).

The third gist of the present invention is that an aluminum billet is processed by extrusion, and at least one surface selected from an inner surface and an outer surface has one or more concave portions formed linearly in the longitudinal direction, or the longitudinal direction. An extruding process for obtaining a cylindrical extruded original pipe having one or more convex portions formed in a straight line, a cutting process for cutting the cylindrical extruded original pipe into a predetermined length, and after the cutting process a cutting step of cutting the outer surface of the cylindrical extruded raw pipe, after the cutting process, possess an ironing step for ironing, at least one of a width selected from the recess and the convex portion, the cylindrical The present invention resides in a method for producing a cylindrical substrate for an electrophotographic photosensitive member, characterized in that the inner diameter is 1/10 or more and 1/5 or less of the inner diameter of the raw extruded tube .

According to a fourth aspect of the present invention, an aluminum billet is processed by extrusion processing, and at least one surface selected from an inner surface and an outer surface is provided with one or more concave portions formed linearly in the longitudinal direction, or in the longitudinal direction. An extrusion process for obtaining a cylindrical extruded raw pipe having one or more linearly formed convex portions, a cutting process for cutting the cylindrical extruded raw pipe into a predetermined length, and after the cutting process, possess a cold drawing step of cold drawing at least one of a width selected from the recess and the convex portion is less than 1/10 of the inner diameter of the cylindrical extruded raw pipe, it is 1/5 or less The present invention resides in a method for producing a cylindrical substrate for an electrophotographic photosensitive member (claim 10 ). In the manufacturing methods according to the third and fourth aspects, the ironing process or the cold drawing process is followed by cutting, honing, blasting, other surface roughening, or a combination thereof, You may have the process of removing or roughening the outer surface of a cylindrical extrusion original pipe (claim 11 ).

According to a fifth aspect of the present invention, there is provided a cylindrical substrate for an electrophotographic photosensitive member produced by any one of the above-described methods for producing a cylindrical substrate for an electrophotographic photosensitive member, and the cylindrical substrate for an electrophotographic photosensitive member. and an organic photosensitive layer formed on, consists in an electrophotographic photosensitive drum, wherein the outer diameter of the electrophotographic photoreceptor is cylindrical substrate is less than [phi] 40 mm (claim 12).
Electrophotographic photosensitive drum, which may have an undercoat layer between the electrophotographic photosensitive member cylindrical substrate and the organic photosensitive layer (claim 13).

  According to the present invention, when a cylindrical substrate for an electrophotographic photosensitive member is manufactured by processing a cylindrical extruded raw tube for an electrophotographic photosensitive member, the dimensional accuracy is hardly lowered due to residual stress or the like, and the number of processing steps is reduced. Can be manufactured with high precision. Therefore, it is possible to manufacture an electrophotographic photosensitive drum suitable for full color image formation at a low cost.

  The items and methods exemplified below are examples (representative examples) of the embodiments of the present invention, and the present invention is not limited to these contents without departing from the gist thereof.

A. Cylindrical Extrusion Pipe for Electrophotographic Photoreceptor The cylindrical extrusion original pipe for an electrophotographic photoreceptor of the present invention is obtained by extruding an aluminum billet. In the present invention, it is formed linearly in the longitudinal direction of the cylindrical extruded original tube for an electrophotographic photosensitive member only on the inner surface, only the outer surface, or both the inner and outer surfaces of the cylindrical extruded raw tube for the electrophotographic photosensitive member. A concave portion (hereinafter sometimes simply referred to as a “concave portion”), or a convex portion (hereinafter simply referred to as a “convex portion”) that is linearly formed in the longitudinal direction of the cylindrical extruded original tube for an electrophotographic photosensitive member. In some cases). That is, the cylindrical extruded original tube for an electrophotographic photosensitive member of the present invention may have only one or more concave portions on only the inner surface or only the outer surface, or may have only one or more convex portions. Good. Moreover, what combined these, ie, what has a recessed part or a convex part, respectively in both surfaces of an inner surface and an outer surface, may be used. When there are recesses or projections on both sides, the number, type, shape, etc. of recesses or projections formed on the inner surface and the number, type, shape, etc. of recesses, projections formed on the outer surface are You may do it, or it may be different.

  Here, the concave portion referred to in the present invention means a portion that is recessed as compared with a cylindrical circular tube having the same outer diameter and inner diameter as the cylindrical extruded original tube for an electrophotographic photosensitive member. That is, the concave portion formed on the outer surface refers to a region that is recessed from the outer surface to the inner surface side as compared with the above cylindrical tube, and the concave portion formed on the inner surface is compared with the above cylindrical tube. Thus, it refers to a region that is recessed from the inner surface to the outer surface side. On the other hand, a convex part means the part which has protruded compared with the said cylindrical circular tube. That is, the convex portion formed on the outer surface refers to a region projecting from the outer surface in the direction opposite to the center of the circle, as compared with the cylindrical tube, and the convex portion formed on the inner surface is the inner surface. An area that protrudes in the direction of the center of the circle.

  Conventionally, when the cross-sectional shape of the extruded original pipe is not uniform, the residual stress accumulated in the original pipe at the time of extrusion is released during subsequent processing, and the dimensional accuracy of the processed portion is reduced. However, in the present invention, by providing the concave portion or the convex portion on either the inner surface or the outer surface of the cylindrical extruded raw tube for an electrophotographic photosensitive member, or on both surfaces, for example, ironing processing, drawing processing, etc. When the subsequent processing is performed, the influence of residual stress is reduced, and the straightness of the formed cylindrical substrate for an electrophotographic photosensitive member can be increased. The reason why the straightness of the cylindrical substrate for electrophotographic photosensitive member obtained by processing the cylindrical extruded raw tube for the electrophotographic photosensitive member of the present invention is not clear, but is presumed as follows.

  As described above, in the conventional extruded original pipe, residual stress (for example, tensile stress or compressive stress) remains in the original pipe, and these are released in a subsequent process such as ironing or drawing. Therefore, it is considered that the bending and warping of the raw tube appear, and the straightness of the obtained raw tube decreases. On the other hand, in the cylindrical extruded raw tube for an electrophotographic photosensitive member of the present invention, a concave or convex portion is linearly provided in advance in the longitudinal direction of the inner or outer surface of the cylindrical extruded raw tube for an electrophotographic photosensitive member. It is considered that the residual stress released in the subsequent process is absorbed and offset by the stress generated by the processing of the concave portion or the convex portion, and does not affect the straightness.

(Concave and convex)
Concave portions or convex portions are formed linearly in the longitudinal direction on the inner and outer surfaces of the cylindrical extruded original tube for an electrophotographic photosensitive member of the present invention. In the present invention, the total number of recesses and protrusions formed on the inner and outer surfaces of the cylindrical extruded raw tube for an electrophotographic photosensitive member may be 1, but is usually 2 or more, preferably 3 or more. It is. In general, the total number of concave portions and convex portions formed on one side, that is, either the inner surface or the outer surface, is usually 1 or more, and preferably 3 or more.

  When only one concave or convex portion is formed on the inner or outer surface of a cylindrical extruded original tube for an electrophotographic photosensitive member, the residual stress originally present in the material and the concave or convex portion are processed. By balancing the stress to be applied, the dimensional accuracy when processing the cylindrical extruded original tube for an electrophotographic photosensitive member is improved. Further, when the total number of the concave portions and the convex portions is 2 or more, the manufacturing apparatus for producing the cylindrical extruded raw tube for the electrophotographic photosensitive member may be complicated, but the effect of the present invention can be more easily obtained. .

  In addition, the plurality of concave portions or convex portions formed linearly in the longitudinal direction of the cylindrical extruded original tube for the electrophotographic photosensitive member are not limited to the cylindrical extruded portion for the electrophotographic photosensitive member unless the object and effect of the present invention are impaired. The original tube may not be formed from end to end in the length direction, but among them, it is preferably formed linearly from end to end in the length direction of the cylindrical extruded original tube for the electrophotographic photosensitive member. . As a result, the effect of the present invention is uniformly exhibited in any cross section of the cylindrical extruded original tube for an electrophotographic photosensitive member, and the straightness of the cylindrical substrate for the electrophotographic photosensitive member is stabilized. The length of the cylindrical extruded original tube for an electrophotographic photosensitive member is usually 20 mm or more, preferably 40 mm or more, depending on the subsequent processing rate. Moreover, it is usually 50 mm or less.

  Moreover, the shape of the circumferential cross section of the cylindrical extruded original tube for an electrophotographic photosensitive member of the concave portion or the convex portion is not particularly limited as long as it does not impair the effect and purpose of the present invention, but is usually rectangular, triangular, or A semicircular shape is preferable from the viewpoint of workability, and these may be formed in combination. In the present invention, a rectangle is particularly preferable among the above.

  In the present invention, when a plurality of concave or convex portions are formed on the outer surface, it is preferable that these are formed at an equal angle around the central axis of the cylindrical extruded raw tube for an electrophotographic photosensitive member, Further, even when a plurality of concave portions or convex portions are formed on the inner surface, it is preferable that these are formed at an equal angle around the central axis of the cylindrical extruded original tube for an electrophotographic photosensitive member. When a plurality of recesses or projections are formed on both sides, the plurality of recesses or projections formed on the outer surface are equiangular about the central axis of the cylindrical extruded original tube for the electrophotographic photosensitive member. Further, it is preferable that a plurality of concave portions or convex portions formed on the inner surface are formed at an equal angle around the central axis of the cylindrical extruded raw tube for an electrophotographic photosensitive member.

  The cylindrical extruded original tube for an electrophotographic photosensitive member of the present invention is usually formed into a cylindrical substrate for an electrophotographic photosensitive member by smoothing the concave portions and the convex portions. Here, in the cylindrical substrate for an electrophotographic photosensitive member in which the concave portions and the convex portions are smoothed, the direction of the residual stress in the region where the concave portions and the convex portions are formed is different from other portions. Therefore, by arranging the recesses and projections on the outer surface at equal intervals, or on the inner surface at equal intervals, it is possible to arrange portions with different residual stress directions at equal intervals on the outer surface and inner surface, respectively. The straightness of the cylindrical substrate for an electrophotographic photoreceptor thus obtained is excellent.

  In addition, the width of each of the concave portion and the convex portion is preferably 1/10 or more, more preferably 1/8 or more, of the inner diameter of the cylindrical extruded original tube for an electrophotographic photosensitive member. Usually, it is preferably 1/5 or less. In both cases where the width is wider than the above range and narrow, the influence of the stress on the cylindrical extruded raw tube for the electrophotographic photosensitive member of the concave portion and the convex portion becomes weak, and the cylindrical portion for the electrophotographic photosensitive member There is a tendency that the effect of improving the straightness of the cylindrical substrate for an electrophotographic photosensitive member obtained by processing the cylindrical extruded original tube is reduced.

  Further, the depth of the concave portion and the height of the convex portion are each preferably 1/10 or more, and more preferably 1/8 or more of the thickness of the cylindrical extruded original tube for an electrophotographic photosensitive member. preferable. Moreover, it is preferable that it is 1/4 or less normally, More preferably, it is 1/5 or less. If the depth of the concave portion is too deep, the cylindrical extruded original tube for the electrophotographic photosensitive member is likely to break during processing, and if too shallow, the influence of the stress on the cylindrical extruded raw tube for the electrophotographic photosensitive member is weakened. , The effect of improving the straightness tends to decrease. In addition, if the height of the convex part is too high, the cylindrical extruded raw tube for the electrophotographic photosensitive member may not easily enter the die or core during ironing or cold drawing, and processing may not be possible. If it is too low, the influence of the stress on the cylindrical extruded original tube for an electrophotographic photosensitive member becomes weak, and the effect of improving the straightness tends to be reduced.

  Here, in the cylindrical extruded raw tube for the electrophotographic photosensitive member of the present invention, a concave or convex portion may be formed only on the inner surface, or a concave or convex portion may be formed only on the outer surface, Moreover, although the recessed part or the convex part may be formed in both surfaces, it is preferable that the recessed part or the convex part is especially formed only in the inner surface. The cylindrical extruded original tube for an electrophotographic photosensitive member of the present invention is generally formed into a cylindrical substrate for an electrophotographic photosensitive member by smoothing a concave portion or a convex portion by an ironing process or a cold drawing process. A photosensitive layer is formed thereon to form an electrophotographic photosensitive drum. Therefore, it is preferable from the viewpoint of the coating property of the photosensitive layer that the outer surface of the cylindrical extruded substrate for an electrophotographic photosensitive member is free from processing marks of concave portions and convex portions.

  In addition, the cylindrical extruded original tube for an electrophotographic photosensitive member may be formed with only a concave portion, may be formed with only a convex portion, or may be formed with both a concave portion and a convex portion. However, in the present invention, it is preferable that only the recesses are formed. When only the concave portion is formed, the cylindrical extruded raw tube for the electrophotographic photosensitive member can be aligned with the outer diameter of the core inserted into the inner surface of the core with a high accuracy in the ironing process or the cold drawing process. This is because it becomes easy.

(Aluminum billet)
The material of the aluminum billet that is the material of the cylindrical extruded raw tube for the electrophotographic photosensitive member of the present invention may be any as long as it is mainly composed of aluminum, and the quality, diameter, cross-sectional area, etc. It is selected appropriately. However, since the type of material may be directly related to the accuracy of the obtained cylindrical extruded original tube for an electrophotographic photosensitive member or the cylindrical substrate for an electrophotographic photosensitive member obtained by processing this, the strength and workability of the material It is preferable to select them comprehensively.

As a preferable aluminum billet, for example, high-purity aluminum such as 1000 series represented by alloy number 1050 defined in JIS H4100-2006, Mn series alloy such as 3000 series represented by alloy number 3003, Examples include Mg series alloys such as No. 5000 series represented by Alloy No. 5052, No. 6000 series Mg—Si series alloys represented by Alloy No. 6063, and the like.
Among these, alloy-based ones are preferable, and in particular, when a cylindrical substrate for an electrophotographic photosensitive member is formed without cutting from a cylindrical extruded raw tube for an electrophotographic photosensitive member, the tensile strength is small and the workability is good. Therefore, it is preferable to use the one having an alloy number of 3000 series.

(Production method)
The method for producing a cylindrical extruded raw tube for an electrophotographic photosensitive member of the present invention is not limited as long as the effects and objects of the present invention are not impaired. For example, after extruding an aluminum billet, one or a plurality of concave portions or convex portions may be formed in various directions in the longitudinal direction of the inner surface or outer surface of the extruded raw tube. Moreover, the method of using a port hole die provided with the recessed part and the convex part in the predetermined position mentioned later, and forming one or some recessed part or convex part at the time of an extrusion process may be sufficient. The latter is particularly preferable from the viewpoint of production efficiency.

  As a method for producing a cylindrical extruded raw tube for an electrophotographic photosensitive member using a general port hole die, for example, the following method can be used. FIG. 1 is a cross-sectional view showing an example of an extrusion processing apparatus using a porthole die used in the present invention. The extrusion processing apparatus illustrated in FIG. 1 has a cylindrical container 1 and a die ring 3 incorporating a port hole die 2, and the aluminum billet to be extruded is conveyed through the container 1 from the right side in the figure. After passing through the port hole die under high temperature and high pressure, it is transported to the left in the figure.

  2 is a cross-sectional view of a conventional male porthole die 2 viewed from the outlet side, and FIG. 3 is a cross-sectional view taken along the line AA. The port hole die 2 is provided with a predetermined number, preferably 3 or more, of substantially triangular inlet port holes 4 on a short axis cylindrical body, and a partition support portion 7 for partitioning each port hole. After the aluminum billet is separated and flows from the port hole inlet 5, it is press-bonded through a small gap between the port hole outlet 6 and the bearing portion 8 to be extruded as a thin cylindrical extruded original pipe. Then, a concave part or a convex part is formed by cutting the extruded raw pipe.

  On the other hand, the following method can be used as a method of forming a concave portion or a convex portion at the time of extrusion using a port hole die provided with a concave portion or a convex portion at a predetermined position. For example, in the processing apparatus shown in FIG. 1, a port hole having a concave portion or a convex portion formed linearly in one or both of the bearing portion 8 and the port hole outlet 6 as shown in FIGS. A die 2 is used to extrude an aluminum billet. In addition, that the recessed part or the convex part is formed linearly means that it is formed linearly in the longitudinal direction of the porthole die 2. Further, the type, position, shape, number, etc. of the concave or convex portions formed in the port hole die 2 are appropriately selected according to the shape of the target cylindrical extruded raw tube for the electrophotographic photosensitive member, and are described above. It corresponds to the concave portion or convex portion of the cylindrical extruded original tube for the electrophotographic photosensitive member.

  4, FIG. 5, and FIG. 6 are cross-sectional views of the male port hole die in which a convex portion is provided on the bearing portion 8 as viewed from the outlet side. For example, when the bearing portion 8 is provided with a concave portion or a convex portion, it is possible to form a corresponding concave portion or convex portion on the inner surface of the cylindrical extruded original tube for the electrophotographic photosensitive member, and the concave portion at the port hole outlet 6. When a convex portion is provided, a corresponding concave portion or convex portion can be formed on the outer surface of the cylindrical extruded original tube for an electrophotographic photosensitive member. In addition, when the concave portion or the convex portion is provided in the bearing portion 8 and the port hole outlet 6, respectively, it is possible to form the concave portion or the convex portion corresponding to the outer surface and the inner surface of the cylindrical extruded original tube for the electrophotographic photosensitive member. .

  When the porthole die 2 shown in FIG. 4 is used, a cylindrical extruded original tube for an electrophotographic photosensitive member having four concave portions having a rectangular shape in the circumferential cross section disposed at an equal angle on the inner surface is obtained. When the port hole die 2 shown in FIG. 5 is used, a cylindrical extruded original tube for an electrophotographic photosensitive member is provided which has four concave portions that are arranged at equal angles on the inner surface and have a triangular cross-sectional shape in the circumferential direction. Further, when the port hole die 2 shown in FIG. 6 is used, a cylindrical extruded raw tube for an electrophotographic photosensitive member having four semicircular recesses having a semicircular shape in the circumferential direction disposed at an equal angle on the inner surface is obtained. It is done. The shape of the port hole die 2 is not limited to the above, and is not limited as long as the object and effect of the present invention are not impaired. For example, a combination of concave and convex portions having different cross-sectional shapes is combined. The thing etc. may be sufficient.

(Use)
The cylindrical extruded raw tube for an electrophotographic photosensitive member of the present invention is subjected to, for example, ironing processing, cold drawing processing, or the like to obtain a cylindrical substrate for an electrophotographic photosensitive member having a desired shape. An organic photosensitive layer or the like is formed on the cylindrical substrate for the photosensitive member to form an electrophotographic photosensitive drum.

  The type of cylindrical substrate for an electrophotographic photosensitive member obtained by processing a cylindrical extruded raw tube for an electrophotographic photosensitive member includes an EI tube in which the surface of the cylindrical extruded raw tube for an electrophotographic photosensitive member is finished by ironing, After performing a drawing process on a non-cutting pipe represented by an ED pipe or the like obtained by cold drawing a cylindrical extruded original tube for an electrophotographic photosensitive member, and a cylindrical extruded original tube for an electrophotographic photosensitive member And a cutting pipe for finishing the outer surface. The cylindrical extruded original tube for an electrophotographic photosensitive member of the present invention can be preferably used for any application. However, in particular, when the non-cutting tube such as the EI tube or the ED tube is used, the straight tube after processing is used. It is preferable because the effect of the present invention that the degree can be made higher can be utilized.

B. Next, the cylindrical substrate for an electrophotographic photosensitive member of the present invention will be described. The cylindrical substrate for an electrophotographic photosensitive member of the present invention is obtained by obtaining a cylindrical extruded original tube having a concave portion or a convex portion formed in the longitudinal direction of the inner surface or outer surface of the cylindrical extruded raw tube by extrusion processing. It is obtained by processing a cylindrical extruded raw tube.

  Since the cylindrical substrate for an electrophotographic photosensitive member of the present invention is obtained by processing a cylindrical extruded original tube having a concave portion or a convex portion, the straightness of the substrate for an electrophotographic photosensitive member can be obtained without going through many steps. Can be high. As described above, this is considered to be due to the residual stress released during processing of the cylindrical extruded original pipe being absorbed and offset by the concave portion or convex portion. Further, since the cylindrical substrate for an electrophotographic photoreceptor of the present invention has high straightness, for example, when forming a photosensitive layer on the surface, the dimensional accuracy can be high even without finishing the surface, It can also be suitable for full-color image formation. Further, there is an advantage that the manufacturing cost can be reduced.

  Hereinafter, a method for producing a cylindrical substrate for an electrophotographic photoreceptor according to the present invention will be described. Note that, as a method for producing a cylindrical substrate for an electrophotographic photosensitive member, two typical embodiments will be described below, but the method for producing a cylindrical substrate for an electrophotographic photosensitive member of the present invention is limited to these embodiments. However, as long as the object and effect of the present invention are not impaired, any method of manufacturing and manufacturing a cylindrical extruded original pipe having a predetermined concave portion or convex portion shall be included in the present invention.

(Production method)
(1) First Embodiment As a first embodiment of the method for producing a cylindrical substrate for an electrophotographic photosensitive member according to the present invention, an aluminum billet is processed by extrusion, and at least one selected from an inner surface and an outer surface is used. An extrusion process for obtaining a cylindrical extruded raw pipe having one or more concave portions formed linearly in the longitudinal direction on the surface, or one or more convex portions formed linearly in the longitudinal direction; A cutting process for cutting the extruded original pipe into a predetermined length, a cutting process for cutting the outer surface of the cylindrical extruded original pipe after the cutting process, and an ironing process for ironing after the cutting process; It is the method which has.

<Extrusion process>
The extrusion process in this embodiment is a process in which an aluminum billet is processed by extrusion to obtain a cylindrical extruded original pipe having a recess or a protrusion on only the inner surface, only the outer surface, or both the inner and outer surfaces. Regarding the shape and number of the concave and convex portions formed on the cylindrical extruded original tube, the aluminum billet used in this step, the method of extruding the aluminum billet, etc., the above-mentioned “A. This may be the same as that described in the section “Extruded original pipe”.

<Cutting process>
After the extrusion process, a cutting process for cutting the cylindrical extruded original pipe into a predetermined length is performed. In the cutting process, the cylindrical extruded raw tube is appropriately cut to a desired length in accordance with the use of the cylindrical substrate for the electrophotographic photosensitive member, that is, the type and shape of the electrophotographic photosensitive drum.

  The cutting method is not particularly limited as long as it can cut the cylindrical extruded raw tube into a predetermined length. For example, a circular saw, a bow saw, a band saw, a roll cutter, a laser, or the like is used for cutting. be able to.

<Cutting process>
After the cutting step, a cutting step for cutting the outer surface of the cylindrical extruded raw pipe is performed. In the cutting process, the outer surface of the cylindrical extruded raw tube is cut to adjust the dimensions and surface state.
For the outer surface cutting of the cylindrical extruded original pipe, a general high precision bearing such as a fluid bearing or a metal bearing is usually used, and a precision lathe that prevents vibration as much as possible is used. This is because the state of the cylindrical substrate surface formed by cutting directly affects the characteristics of the electrophotographic photosensitive drum. The outer surface cutting is performed using, for example, a diamond sintered body with a cutting depth of about 200 μm or less.

<Sieving process>
After the above cutting process, the ironing process of the cylindrical extruded raw pipe is performed. The ironing process can be performed by EI processing.

<Other processes>
In the method for producing a cylindrical substrate for an electrophotographic photoreceptor according to this embodiment, other steps are appropriately included as necessary before and after each step described above, or between each step, and further during each step. Also good. In addition, after the ironing process, a process of removing or roughening the outer surface of the cylindrical extruded raw pipe by cutting, honing, blasting, other roughening treatments, or a combination thereof is also necessary. Done.

Also, after the ironing process, by removing the outer surface of the cylindrical extruded raw pipe, an oxide film with a non-uniform thickness generated on the outer surface of the pipe, oil and dirt strongly adhered, aluminum powder, surface scratches, etc. Can be removed. In addition, after the ironing process, by roughening the outer surface of the cylindrical extruded raw tube, interference with laser light can be prevented when used as a cylindrical substrate for an electrophotographic photosensitive member. The roughening as used in the present invention means that fine fine irregularities are periodically or randomly formed on the surface.
As the cutting process for performing the above-described treatment, for example, a cutting tool such as a diamond tool can be used. Moreover, you may perform a honing process. Blasting may also be performed. For example, blasting is performed by removing surface defects on the outer surface by spraying sand grains, corundum, carborundum, glass beads, metal powder, etc. on the outer surface of the extruded raw tube. The method of facing is mentioned.
Other examples of the roughening treatment include brushing with a resin brush containing an abrasive.
These processes may be performed in combination as appropriate.

(2) Second Embodiment As a second embodiment of the method for producing a cylindrical substrate for an electrophotographic photosensitive member according to the present invention, an aluminum billet is processed by extrusion, and at least one selected from an inner surface and an outer surface is used. An extrusion process for obtaining a cylindrical extruded raw pipe having one or more concave portions formed linearly in the longitudinal direction on the surface, or one or more convex portions formed linearly in the longitudinal direction; It is a method having a cutting process step of cutting the extruded original pipe into a predetermined length and a cold drawing process step of cold drawing after the cutting process step.

  In this embodiment, you may have the cutting process which cuts after this cold drawing process.

  In addition, since it can be set as the process similar to the 1st embodiment mentioned above about the extrusion process, cutting process, and cutting process in this embodiment, processes other than these are demonstrated below.

<Cold drawing process>
After the extrusion process and the cutting process, a cold drawing process for cold drawing the cylindrical extruded raw pipe is performed.
Cold drawing is done by installing a die called a die on the inner diameter side and a die called a die on the outer diameter side, and extending the inner diameter and outer diameter at the same time. May cause residual stress. Usually, after cold drawing, it is cut to align the cylindrical extruded raw tube to a predetermined length.

<Other processes>
In the method for producing a cylindrical substrate for an electrophotographic photoreceptor according to this embodiment, other steps are appropriately included as necessary before and after each step described above, or between each step, and further during each step. Also good. For example, in this embodiment, an inlay process can be performed as necessary. In addition, after the cold drawing process, it is also necessary to remove or roughen the outer surface of the cylindrical extruded original pipe by cutting, honing, blasting, other roughening treatments, or a combination of these. Will be done accordingly. The step of removing or roughening the outer surface of the cylindrical extruded raw tube can be the same as the method described in the first embodiment.

  The inlay processing step is a step of cutting the inside of the raw tube to form a step portion (inlay portion) to which the flange is to be attached. The thickness and depth to be reduced are determined according to the outer diameter and height of the flange to be mounted, and an inlay portion is formed. The inlay processing is preferably simultaneous processing at both ends in order to make the coaxiality, the perpendicularity of the end face, etc. highly accurate. As a machine for this purpose, a both-end processing machine is used, and a method is adopted in which the outer tube or the inner tube is gripped by a collet chuck and the tube or blade is rotated to process.

(Preferred dimensions)
Since the cylindrical substrate for an electrophotographic photosensitive member manufactured by the above-described manufacturing method is excellent in dimensional accuracy, the outer diameter of the cylindrical substrate for an electrophotographic photosensitive member of the present invention is preferably less than φ40 mm, and φ30 mm. It is more preferable that the diameter is less than 25 mm. Moreover, it is usually φ10 mm or more, particularly preferably φ15 mm or more. In the cylindrical substrate for an electrophotographic photosensitive member having an outer diameter in such a range, the influence of dimensional accuracy is likely to appear, and the advantages of the present invention can be utilized.

C. Electrophotographic Photosensitive Drum The electrophotographic photosensitive drum of the present invention has an undercoat layer directly or directly on the cylindrical substrate for an electrophotographic photosensitive member produced by the above-described method for producing a cylindrical substrate for an electrophotographic photosensitive member. An organic photosensitive layer is formed thereon, and the outer diameter of the cylindrical substrate for an electrophotographic photosensitive member is less than φ40 mm. That is, it may have a structure in which an undercoat layer is formed on the above-described cylindrical substrate for an electrophotographic photosensitive member, and an organic photosensitive layer is further formed thereon. Alternatively, the organic photosensitive layer may be directly formed.

According to the present invention, since the cylindrical substrate for an electrophotographic photosensitive member manufactured by processing the cylindrical extruded raw tube having the above-described concave portion and convex portion is used, the straightness of the cylindrical substrate for the electrophotographic photosensitive member is used. And can be manufactured at a low cost. Therefore, the electrophotographic photosensitive drum of the present invention has high dimensional accuracy and can be suitable for, for example, full-color image formation.
Hereinafter, the organic photosensitive layer and the undercoat layer in the electrophotographic photosensitive drum of the present invention will be described.

(Organic photosensitive layer)
The organic photosensitive layer formed on the electrophotographic photosensitive drum of the present invention is not particularly limited as long as the effects and objects of the present invention are not impaired. For example, the organic photosensitive layer contains a charge generation layer containing a charge generation material and a charge transport material. It may be a laminated organic photosensitive layer composed of a charge transport layer, or a single layer organic photosensitive layer in which a charge generating material is dispersed in a layer containing a charge transport material.

  When the organic photosensitive layer is a single layer type, a single coating solution is prepared by mixing a charge generating substance, a charge transporting substance, a binder resin and a solvent, which will be described later, on the cylindrical substrate for the electrophotographic photosensitive member. Alternatively, it can be formed by coating on the undercoat layer. When the organic photosensitive layer is a laminated type, a coating solution for a charge generation layer in which a charge generation material, a binder resin and a solvent are mixed, and a charge transport layer for which a charge transport material, a binder resin and a solvent are mixed. The coating solution can be prepared separately and applied on the cylindrical substrate for the electrophotographic photosensitive member or on the undercoat layer according to the order of formation. In the present invention, the stacking order of the charge transport layer and the charge generation layer is not particularly limited.

  The concentration of each component in each coating solution is appropriately selected according to a known method. The concentration of the solid content is mainly determined according to the film thickness of the layer to be formed. For example, a coating solution for forming a single-layer type organic photosensitive layer or a coating solution for a multilayer charge transport layer is used. Is usually 40% by weight or less, preferably 35% by weight or less, and usually 10% by weight or more. Further, the viscosity of these coating solutions is usually 50 cp or more, and usually 300 cp or less. Further, the dry film thickness of the organic photosensitive layer is usually 15 μm or more, and usually 40 μm or less.

<Charge generating material>
For example, as the charge generation material used in the organic photosensitive layer, any known charge generation material may be used alone, or two or more types may be used in any combination and ratio.
Examples of charge generation materials include azo pigments such as Sudan Red, Diane Blue, and Genus Green B; quinone pigments such as disazo pigments, argol yellow, and pyrenequinone; quinocyanine pigments, perylene pigments, indigo pigments, and Indian first orange toner. Examples thereof include benzimidazole pigments, phthalocyanine pigments such as copper phthalocyanine, quinacridone pigments, pyrylium salts, and azulenium salts.

<Charge transport material>
Further, as the charge transport material, any known charge transport material may be used alone, or two or more kinds may be used in any combination and ratio.
As a charge transport material, for example, in the main chain or side chain, a skeleton of a polycyclic aromatic compound such as anthracene, pyrene, phenanthrene, coronene or indole, carbazole, oxazole, isoxazole, thiazole, imidazole, pyrazole, oxadiazole, pyrazoline , Compounds having a skeleton of a nitrogen-containing cyclic compound such as thiadiazole and triazole. In addition, a hole transport material such as a hydrazone compound may be used.

<Binder resin>
As the binder resin, any known binder resin can be used alone, or two or more kinds can be used in any combination and ratio.
Examples of binder resins include polycarbonate, polyacrylate, polystyrene, polymethacrylate, styrene-methyl methacrylate copolymer, polyester, styrene-acrylonitrile copolymer, polysulfone, polyvinyl acetate, polyacrylonitrile, polyvinyl butyral, polyvinyl pyrrolidone, methyl cellulose, and hydroxymethyl cellulose. And cellulose esters.

<Solvent>
As the solvent, for example, a solvent usually used in the production of an electrophotographic photoreceptor is used. Examples of such a solvent include n-butylamine, diethylamine, ethylenediamine, isopropanolamine, triethanolamine, N, N-dimethylformamide, acetone, methyl ethyl ketone, cyclohexanone, benzene, 4-methoxy-4-methylpentanone-2. , Dimethoxymethane, dimethoxyethane, 2,4-pentadione, anisole, methyl 3-oxobutanoate, monochlorobenzene, toluene, xylene, chloroform, 1,2-dichloroethane, dichloromethane, tetrahydrofuran, dioxane, methanol, ethanol, isopropanol, ethyl acetate , Butyl acetate, dimethyl sulfoxide, methyl cellosolve, ethyl cellosolve, methyl cellosolve acetate and the like. At best, it may be used in combination of two or more kinds in any combination and in any ratio.

<Application method>
In the present invention, the coating operation for forming each of the layers follows a conventionally known coating method. For example, a dipping method, a spray coating method, a spinner coating method, a blade coating method, or the like can be employed.

  After the coating film is formed by the above coating method, the coating film is dried, but it is preferable to adjust the drying temperature and time so that necessary and sufficient drying is performed. If the drying temperature is too high, bubbles may be mixed in the photosensitive layer. If the drying temperature is too low, it takes time to dry, and the amount of residual solvent may increase and affect electrical characteristics. , Preferably it is 110 degreeC or more, More preferably, it is 120 degreeC or more. Moreover, it is 250 degrees C or less normally, Preferably it is 170 degrees C or less, More preferably, it is 140 degrees C or less. As a drying method, a hot air dryer, a steam dryer, an infrared dryer, a far infrared dryer, or the like can be used.

(Underlayer)
The electrophotographic photosensitive drum of the present invention may have an undercoat layer between the organic photosensitive layer and the cylindrical substrate for the electrophotographic photosensitive member. As the undercoat layer, a resin, a resin in which particles such as a metal oxide are dispersed, or the like is used. Examples of metal oxide particles used for the undercoat layer include metal oxide particles containing one metal element such as titanium oxide, aluminum oxide, silicon oxide, zirconium oxide, zinc oxide, iron oxide, calcium titanate, titanium Examples thereof include metal oxide particles containing a plurality of metal elements such as strontium acid and barium titanate. In the undercoat layer, only one kind of the particles may be used, or a plurality of kinds of particles may be mixed and used in an arbitrary ratio and combination.

  Among the metal oxide particles, titanium oxide and aluminum oxide are preferable, and titanium oxide is particularly preferable. The surface of the titanium oxide particles may be treated with an inorganic substance such as tin oxide, aluminum oxide, antimony oxide, zirconium oxide or silicon oxide, or an organic substance such as stearic acid, polyol or silicone. As the crystal form of the titanium oxide particles, any of rutile, anatase, brookite, and amorphous can be used. Moreover, the thing of a several crystal state may be contained.

  The particle size of the metal oxide particles used for the undercoat layer is not particularly limited, but is 10 nm as the average primary particle size from the standpoint of the properties of the undercoat layer and the stability of the solution for forming the undercoat layer. The thickness is preferably 100 nm or less, more preferably 50 nm or less.

  Here, the undercoat layer is preferably formed in a form in which the metal oxide particles are dispersed in a binder resin. As the binder resin used for the undercoat layer, for example, phenoxy resin, epoxy resin, polyvinyl pyrrolidone, polyvinyl alcohol, casein, polyacrylic acid, celluloses, gelatin, starch, polyurethane, polyimide, polyamide, etc. are cured alone or with a curing agent. Can be used. These may be used individually by 1 type, and may use 2 or more types by arbitrary ratios and combinations. Among these, alcohol-soluble copolymerized polyamides, modified polyamides, and the like are preferable because they exhibit good dispersibility and coatability.

  The mixing ratio of the metal oxide particles to the binder resin can be arbitrarily selected, but it is preferably used in the range of 10% by weight to 500% by weight in terms of the stability of the dispersion and the coating property. The thickness of the undercoat layer can be arbitrarily selected, but is usually preferably 0.1 μm or more and 20 μm or less from the characteristics of the electrophotographic photosensitive member and the applicability of the dispersion. The undercoat layer may contain a known antioxidant or the like.

(Other layers)
The electrophotographic photosensitive drum of the present invention may have other layers as necessary in addition to the above-described cylindrical substrate for an electrophotographic photosensitive member, an organic photosensitive layer, and an undercoat layer. A protective layer or the like may be provided on the photosensitive layer for the purpose of preventing electrical and mechanical deterioration.

(Use of electrophotographic photosensitive drum)
The type or the like of the image forming apparatus in which the electrophotographic photosensitive drum of the present invention is used is not particularly limited, and can be applied to a known image forming apparatus. Since the electrophotographic photosensitive drum of the present invention is particularly excellent in dimensional accuracy, it can be suitably used for an image forming apparatus for full color image formation in which high dimensional accuracy is required for the electrophotographic photosensitive drum. is there.

EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to a following example, unless it deviates from the summary. In the following examples and comparative examples, straightness is defined in JIS B0621-1984, and the measurement is performed using a non-contact dimension measuring device (trade name RA-801, manufactured by Mitutoyo Corporation). went.
In the following description, “part” represents “part by weight” unless otherwise specified.

[Example 1]
In the extrusion processing apparatus shown in FIG. 1, the port hole die 2 shown in FIG. 4 having an outer diameter of the port hole entrance portion of 130 mm is used, and the outer diameter is 178 mm of JIS3003 alloy (type H112, tensile strength 110 N / mm ² ) Was extruded using an aluminum billet to produce a cylindrical extruded original tube having an outer diameter of 35 mm and an inner diameter of 30 mm. The width of each of the four rectangular convex portions provided on the bearing portion 8 of the porthole die 2 in FIG. 4 is about 4 mm and the height is about 0.4 mm. On the inner surface, four equiangular rectangular recesses each having a width of about 4 mm and a depth of about 0.4 mm were linearly formed. The cylindrical extruded raw tube was cut every 100 mm in length.

  Thereafter, the outer surface layer of the cylindrical extruded original tube is cut to a depth of about 0.2 mm from the surface using a diamond tool, and then ironed to give an outer diameter of 30 mm, a wall thickness of 1 mm, and then a length of 340 mm. To obtain a cylindrical substrate A for an electrophotographic photosensitive member. Table 1 shows the result of measuring the dimensional accuracy (straightness) of the cylindrical substrate A for electrophotographic photosensitive member.

<Formation of undercoat layer>
Γ-mercaptopropyltrimethoxysilane (product name TSL8380, manufactured by Toshiba Silicone Co., Ltd.) 5 with respect to rutile-type white titanium oxide having an average primary particle size of 40 nm (Ishihara Sangyo Co., Ltd., product name TTO55N) and 100 parts of the titanium oxide. Parts were mixed in a ball mill, and the resulting slurry was baked at 120 ° C. for 1 hour to prepare surface-treated titanium oxide. Next, this surface-treated titanium oxide is subjected to ball mill dispersion in a mixed solvent of methanol / 1-propanol = 7/3, and a γ-mercaptopropyltrimethoxysilane-treated titanium oxide dispersion having a solid content concentration of 33.3% by weight is obtained. Obtained.
The titanium oxide dispersion obtained here was a mixed alcohol (methanol / 1-propanol = 70 /) of a random copolymerized polyamide having the following structural formula produced by the production method described in the example of JP-A-4-31870. 30) Mixing with the solution, finally, a dispersion having a titanium oxide / nylon ratio of 3/1 (weight ratio) and a solid concentration of 16% by weight was prepared, and this was used as dispersion (P1).

前記電子写真感光体用円筒状基体Ａ上に、分散液Ｐ１を、その乾燥膜厚が０．７５μｍとなるように浸漬塗布して下引き層を設けた。

On the cylindrical substrate A for the electrophotographic photosensitive member, the dispersion P1 was dip-coated so that the dry film thickness was 0.75 μm to provide an undercoat layer.

<Formation of organic photosensitive layer>
Next, the powder X-ray diffraction spectrum by CuKα characteristic X-ray has a Bragg angle 2θ ± 0.2 and has strong peaks at 10.5 °, 26.2 °, and 27.2 °. 1 part, 500 parts of 1,2-dimethoxyethane was added to 5 parts of polyvinyl butyral (trade name # 6000-C, manufactured by Denki Kagaku Kogyo Co., Ltd.), and pulverized and dispersed by a sand grind mill. This dispersion was dip-coated on the previously provided undercoat layer, and a charge generation layer was provided so that the dry film thickness was about 0.3 μm.
Next, 56 parts by weight of hydrazone compound A shown below, 14 parts by weight of hydrazone compound B, 1.5 parts by weight of cyanide compound shown below, and the production method described in the examples of JP-A-3-221196 A coating solution prepared by dissolving 100 parts of the polycarbonate resin shown below having two repeating structural units thus prepared in 620 parts by weight of a mixed solvent of 1,4 dioxane: tetrahydrofuran = 65: 25 is placed on the charge generation layer. By dip coating, a charge transport layer was provided so that the dry film thickness was 17 μm. The electrophotographic photosensitive drum thus obtained is referred to as an electrophotographic photosensitive drum A.

<Evaluation>
Using a Casio tandem color laser printer ColorPageprest N4-612II, each of the four color imaging units was equipped with an electrophotographic photosensitive drum A, and a full color image was formed at an exposure density of 600 dpi. A high-quality image with little fogging, no unevenness, color shift, and insufficient resolution was obtained. In addition, about 4000 full-color images were formed repeatedly, but there was almost no difference from the initial stage.

[Example 2]
A cylindrical extruded original tube was produced in the same manner as in Example 1 except that the port hole die shown in FIG. 5 was used. The maximum width of each of the four triangular convex portions provided on the bearing portion 8 of the port hole die 2 in FIG. 5 is about 4 mm and the height is about 0.4 mm. The formed cylindrical extruded original pipe Four equiangular triangular recesses each having a maximum width of about 4 mm and a depth of about 0.4 mm were formed in a linear shape on the inner surface. Thereafter, a cylindrical substrate B for an electrophotographic photosensitive member was obtained in exactly the same manner as in Example 1.

  Table 1 shows the result of measuring the dimensional accuracy (straightness) of the cylindrical substrate B for the electrophotographic photosensitive member. Using the cylindrical substrate B for an electrophotographic photosensitive member, coating was performed in the same manner as in Example 1 to obtain an electrophotographic photosensitive drum B. Then, image formation was carried out in the same manner as in Example 1, and full color images were evaluated. As a result, good results equivalent to those in Example 1 were obtained.

[Example 3]
A cylindrical extruded original tube was produced in the same manner as in Example 1 except that the port hole die shown in FIG. 6 was used. The maximum width of each of the four semicircular protrusions provided on the bearing portion 8 of the porthole die 2 in FIG. 6 is about 4 mm and the height is about 0.4 mm. On the inner surface, four equiangular semicircular recesses each having a maximum width of about 4 mm and a depth of about 0.4 mm were linearly formed. Thereafter, a cylindrical substrate C for an electrophotographic photosensitive member was obtained in exactly the same manner as in Example 1. Table 1 shows the result of measuring the dimensional accuracy (straightness) of the cylindrical substrate C for electrophotographic photosensitive member.

  An electrophotographic photosensitive drum C was obtained in the same manner as in Example 1 using the cylindrical substrate C for the electrophotographic photosensitive member. Then, image formation was carried out in the same manner as in Example 1, and full color images were evaluated. As a result, good results equivalent to those in Example 1 were obtained.

[Example 4]
The extruded original pipe of Example 1 was subjected to cold drawing and further cut to produce a drawn pipe having an outer diameter of 30 mm, a thickness of 1 mm, and a length of 340 mm. This drawing tube was used as a cylindrical substrate D for an electrophotographic photoreceptor as it was.

  Table 1 shows the result of measuring the dimensional accuracy (straightness) of the cylindrical substrate D for electrophotographic photosensitive member. An electrophotographic photosensitive drum D was obtained in the same manner as in Example 1 using the cylindrical substrate D for the electrophotographic photosensitive member. Further, image formation was carried out in the same manner as in Example 1, and full color images were evaluated. As a result, good results equivalent to those in Example 1 were obtained.

[Example 5]
The extruded original pipe of Example 1 was subjected to cold drawing and further cut to produce a drawn pipe having an outer diameter of 30.5 mm, a wall thickness of 1.25 mm, and a length of 340 mm. Next, this raw tube was set on a both-end processing machine manufactured by Changun Factory, and subjected to inlay processing under the conditions of a rotation speed of 1000 rpm and a feed of 0.2 mm. Furthermore, this raw tube is set in a SPA500 manufactured by Changun Kogakusho, and is subjected to rough cutting with a cutting depth of 0.23 mm and finishing cutting with a cutting depth of 0.02 mm under the conditions of a rotational speed of 2000 rpm and a feed of 0.2 mm. A cylindrical body E for body was obtained. Table 1 shows the result of measuring the dimensional accuracy (straightness) of the cylindrical substrate E for electrophotographic photosensitive member.

  An electrophotographic photosensitive drum E was obtained in the same manner as in Example 1 using the cylindrical substrate E for an electrophotographic photosensitive member. When an image was formed in the same manner as in Example 1 and a full-color image was evaluated, good results equivalent to those in Example 1 were obtained.

[Comparative Example 1]
In Example 1, a cylindrical extruded raw tube was produced in the same manner except that the conventional port hole die shown in FIG. 2 was used. In addition, the obtained original pipe does not have the unevenness | corrugation concerning this invention. Thereafter, a cylindrical substrate F for an electrophotographic photosensitive member was obtained in exactly the same manner as in Example 1. Table 1 shows the results of measuring the dimensional accuracy (straightness) of the cylindrical substrate F for the electrophotographic photosensitive member.

  An electrophotographic photosensitive drum F was obtained in the same manner as in Example 1 using the cylindrical substrate F for the electrophotographic photosensitive member. Then, when a live-action image was taken and a full-color image was evaluated in the same manner as in Example 1, there was slight color misalignment and unevenness at the edge of the image, which seemed to be due to the accuracy of the tube.

[Comparative Example 2]
The extruded raw pipe of Comparative Example 1 was subjected to cold drawing and further cut to produce a drawn pipe having an outer diameter of 30 mm, a thickness of 1 mm, and a length of 340 mm. This drawing tube was used as a cylindrical substrate G for an electrophotographic photoreceptor as it was. Table 1 shows the results of measuring the dimensional accuracy (straightness) of the cylindrical substrate G for the electrophotographic photosensitive member.

  Example 1 and an electrophotographic photosensitive drum G were obtained using a cylindrical substrate G for an electrophotographic photosensitive member. Thereafter, image formation was carried out in the same manner as in Example 1 and full-color images were evaluated. As a result, there were slight color shifts and unevenness at the edge of the image, which seemed to be due to the accuracy of the tube.

[Comparative Example 3]
The extruded raw pipe of Comparative Example 1 was subjected to cold drawing and further cut to produce a drawn pipe having an outer diameter of 30.5 mmφ, a wall thickness of 1.25 mm, and a length of 340 mm. Next, this raw tube was set on a both-end processing machine manufactured by Changun Factory, and subjected to inlay processing under the conditions of a rotation speed of 1000 rpm and a feed of 0.2 mm. Furthermore, this raw tube is set in a SPA500 manufactured by Changun Kogakusho, and is subjected to rough cutting with a cutting depth of 0.23 mm and finishing cutting with a cutting depth of 0.02 mm under the conditions of a rotational speed of 2000 rpm and a feed of 0.2 mm. A cylindrical body H for body was obtained. Table 1 shows the result of measuring the dimensional accuracy (straightness) of the cylindrical substrate H for the electrophotographic photosensitive member.

  An electrophotographic photosensitive drum H was obtained in the same manner as in Example 1 using the cylindrical substrate H for the electrophotographic photosensitive member. Thereafter, image formation was carried out in the same manner as in Example 1, and full-color images were evaluated. As a result, there were slight color shifts and unevenness at the edge of the image that seemed to be due to the accuracy of the tube.

  The electrophotographic photosensitive drum of the present invention can be manufactured with low dimensional accuracy and at low cost, and even in full-color image formation, image formation can be performed efficiently with uniform quality. Therefore, the present invention can be suitably used in the fields of copiers, printers, printing machines, and the like.

It is a cross-sectional view of an extrusion processing apparatus using a conventional porthole die. It is sectional drawing which looked at the male type | mold of the conventional porthole die from the exit side. It is a cross-sectional view of a conventional porthole die. It is sectional drawing which looked at the male type | mold of the porthole die of this invention from the exit side. It is sectional drawing which looked at the male type | mold of the other porthole die of this invention from the exit side. It is sectional drawing which looked at the male type | mold of the other porthole die of this invention from the exit side.

Explanation of symbols

1: Container 2: Port hole die 3: Die ring 4: Port hole 5: Port hole inlet 6: Port hole outlet 7: Partition support portion 8: Bearing portion

Claims (13)

A cylindrical extruded raw tube for an electrophotographic photosensitive member obtained by subjecting an aluminum billet to extrusion processing,
At least one surface selected from the inner and outer surfaces of the cylindrical extruded original tube for the electrophotographic photosensitive member,
One or more concave portions formed linearly in the longitudinal direction of the cylindrical extruded original tube for the electrophotographic photosensitive member, or convex portions formed linearly in the longitudinal direction of the cylindrical extruded raw tube for the electrophotographic photosensitive member part possess one or more,
The width of at least one selected from the concave portion and the convex portion is 1/10 or more and 1/5 or less of the inner diameter of the cylindrical extruded original tube for an electrophotographic photosensitive member. Cylindrical extrusion tube for photographic photoreceptor. A plurality of the concave portions or the convex portions are formed at equal angles on the outer surface of the cylindrical extruded original tube for the electrophotographic photosensitive member, with the central axis of the cylindrical extruded raw tube for the electrophotographic photosensitive member as the center, or 2. The cylindrical extruded original tube for an electrophotographic photosensitive member according to claim 1, wherein the cylindrical extruded original tube is formed at an equal angle on the inner surface.   3. The cylindrical extruded original tube for an electrophotographic photosensitive member according to claim 1, wherein the total number of the concave portions and the convex portions is 3 or more. The shape of the circumferential cross section of the cylindrical extruded raw tube for an electrophotographic photosensitive member selected from at least one of the concave portion and the convex portion is any of a rectangular shape, a triangular shape, and a semicircular shape. A cylindrical extruded original tube for an electrophotographic photosensitive member according to any one of claims 1 to 3 . At least one selected from the depth of the concave portion and the height of the convex portion is 1/10 or more and 1/4 or less of the thickness of the cylindrical extruded raw tube for the electrophotographic photosensitive member. A cylindrical extruded raw tube for an electrophotographic photosensitive member according to any one of claims 1 to 4 . Only the inner surface of the electrophotographic photoreceptor is cylindrical extruded raw pipe, an electrophotographic photoreceptor according to any one of claims 1 to 5, characterized in that it has a recess or convex portions of one or more Cylindrical extrusion tube. The cylindrical extruded original tube for an electrophotographic photosensitive member according to any one of claims 1 to 6 , wherein the cylindrical extruded raw tube has only one or more concave portions. A method of manufacturing a cylindrical extruded raw tube for an electrophotographic photosensitive member from an aluminum billet by an extrusion method using a porthole die,
At least one selected from the bearing part and the port hole outlet part, using the port hole die having one or more linearly formed concave parts, or one or more linearly formed convex parts ,
The width of at least one selected from the concave portion and the convex portion is 1/10 or more and 1/5 or less of the inner diameter of the cylindrical extruded original tube for an electrophotographic photosensitive member. A method for producing a cylindrical extruded raw tube for a photographic photoreceptor. An aluminum billet is processed by extrusion processing, and at least one surface selected from an inner surface and an outer surface has one or more concave portions formed linearly in the longitudinal direction, or a convex portion formed linearly in the longitudinal direction. An extrusion process to obtain a cylindrical extruded raw tube having one or more;
A cutting process for cutting the cylindrical extruded raw tube into a predetermined length;
A cutting step of cutting the outer surface of the cylindrical extruded raw tube after the cutting step;
After the cutting process, it has a and ironing step for ironing,
The cylinder for an electrophotographic photosensitive member, wherein the width of at least one selected from the concave portion and the convex portion is 1/10 or more and 1/5 or less of the inner diameter of the cylindrical extruded original tube. Method for manufacturing a substrate. An aluminum billet is processed by extrusion processing, and at least one surface selected from an inner surface and an outer surface has one or more concave portions formed linearly in the longitudinal direction, or a convex portion formed linearly in the longitudinal direction. An extrusion process to obtain a cylindrical extruded raw tube having one or more;
A cutting process for cutting the cylindrical extruded raw tube into a predetermined length;
After the cutting step, it possesses a cold drawing step of cold drawing,
The cylinder for an electrophotographic photosensitive member, wherein the width of at least one selected from the concave portion and the convex portion is 1/10 or more and 1/5 or less of the inner diameter of the cylindrical extruded original tube. Method for manufacturing a substrate. After the ironing step or the cold drawing step, the outer surface of the cylindrical extruded raw pipe is removed or roughened by cutting, honing, blasting, other roughening treatment, or a combination thereof. The method for producing a cylindrical substrate for an electrophotographic photosensitive member according to claim 9 or 10 , characterized by comprising the step of: A cylindrical substrate for an electrophotographic photosensitive member manufactured by the method for manufacturing a cylindrical substrate for an electrophotographic photosensitive member according to any one of claims 9 to 11 , and on the cylindrical substrate for an electrophotographic photosensitive member. An organic photosensitive layer formed,
An electrophotographic photosensitive drum, wherein an outer diameter of the cylindrical substrate for the electrophotographic photosensitive member is less than φ40 mm. The electrophotographic photosensitive drum according to claim 12 , further comprising an undercoat layer between the cylindrical substrate for the electrophotographic photosensitive member and the organic photosensitive layer.

Images