JP2007334342A - Electrophotographic photosensitive body, method for producing conductive base, image forming device and electrophotographic cartridge - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high-performance electrophotographic photosensitive body which hardly produces image defects such as black spots, colored spots or interference fringes. <P>SOLUTION: The electrophotographic photosensitive body comprises, on a conductive base whose surface has a maximum height of the profile (Rz) satisfying 0.8≤Rz≤2 μm, a foundation layer containing metal oxide particles and a binder resin, and a photosensitive layer formed on the foundation layer. In this electrophotographic photosensitive body, the metal oxide particles of the foundation layer dispersed in a solvent obtained by mixing methanol and 1-propanol at a weight ratio of 7:3 have a volume average particle diameter of ≤0.1 μm and a cumulative 90% particle diameter of ≤0.3 μm, as measured by dynamic light scattering. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electrophotographic photosensitive member, a method for producing a conductive substrate used therefor, an image forming apparatus using the same, and an electrophotographic cartridge.

In recent years, electrophotographic technology has been widely used and applied not only in the field of copying machines but also in the field of various printers because of its immediacy and high-quality images. Electrophotographic photoreceptors (hereinafter referred to simply as “photoreceptors”), which are the core of electrophotographic technology, have advantages such as non-pollution and easy manufacturing compared to inorganic photoconductive materials as photoconductive materials. An organic photoconductor using an organic photoconductive material having the above has been developed.
Usually, the organic photoreceptor is formed by forming a photosensitive layer on a conductive substrate (conductive support). As a type of the photoreceptor, a so-called single-layer photoreceptor having a single-layer photosensitive layer (single-layer photosensitive layer) in which a photoconductive material is dissolved or dispersed in a binder resin; a charge containing a charge generating substance A so-called laminated photoreceptor having a photosensitive layer (laminated photosensitive layer) composed of a plurality of layers formed by laminating a generation layer and a charge transporting layer containing a charge transporting substance is known.

In an organic photoreceptor, various defects may be seen in an image formed using the photoreceptor due to changes in the usage environment of the photoreceptor or changes in electrical characteristics due to repeated use. One technique for improving this is to provide an undercoat layer having a binder resin and titanium oxide particles between a conductive substrate and a photosensitive layer in order to stably form a good image. (For example, refer to Patent Document 1).
The layer of the organic photoreceptor is usually formed by applying and drying a coating solution in which a material is dissolved or dispersed in various solvents because of its high productivity. At this time, in the undercoat layer containing the titanium oxide particles and the binder resin, since the titanium oxide particles and the binder resin exist in an incompatible state in the undercoat layer, the undercoat layer forming coating solution is The coating is formed by a coating liquid in which titanium oxide particles are dispersed.

Conventionally, such a coating liquid is produced by wet-dispersing titanium oxide particles in an organic solvent with a known mechanical grinding device such as a ball mill, a sand grind mill, a planetary mill, or a roll mill for a long time. It was common (see, for example, Patent Document 1). When the titanium oxide particles in the coating solution for forming the undercoat layer are dispersed using a dispersion medium, the material of the dispersion medium is made of titania or zirconia, so that an electron having excellent charge exposure repeatability even under low temperature and low humidity conditions. It is disclosed that a photographic photoreceptor can be provided (see, for example, Patent Document 2).
In general, titanium oxide particles are aggregated into secondary particles, and it is known that image defects such as black spots and color spots are reduced by dispersing the particles in a form close to primary particles. Yes.

On the other hand, when image formation is performed using a photoreceptor, image unevenness called interference fringes may occur as one type of image defect. This is because writing light from a laser or a light emitting diode (LED) reflects and interferes with the substrate surface of the electrophotographic photosensitive member or the coating film interface, and the light intensity acting on the charge generation layer is uneven due to a subtle difference in the coating film thickness. This occurs because the sensitivity changes depending on the site.
As a measure for preventing this interference fringe defect, a method of roughening the surface of the substrate is effective, and various roughening methods have been proposed (Patent Documents 3 to 9).

Japanese Patent Laid-Open No. 11-202519 Japanese Patent Laid-Open No. 6-273963 JP 2000-105481 A JP-A-6-138683 JP 2001-296679 A JP-A-5-224437 JP-A-8-248660 JP-A-6-138683 Japanese Patent Laid-Open No. 1-123246

However, if the roughness of the substrate surface is too large, the roughness of the substrate will adversely affect the uniformity of the coating film thickness formed on the substrate, or burrs will occur on the substrate, resulting in locally thin coating film thickness. And image defects such as black spots, black streaks, and color spots may occur on the image.
In addition, metal oxide particles such as titanium oxide dispersed in the undercoat layer have an effect of relaxing interference fringes in that light written by a laser or LED is scattered. However, if the metal oxide particles are dispersed in a form close to the primary particles in order to reduce image defects such as black spots and color spots, the interference fringe mitigating effect by the undercoat layer is reduced, and the interference fringes on the image are reduced. To increase. Furthermore, if the surface of the substrate is significantly roughened to reduce interference fringes, the result is an increase in image defects such as black spots, color spots, and black stripes.

As described above, many of the image defects are still insufficient in terms of reducing all image defects in a balanced manner.
The present invention has been made in view of the background of the above-described electrophotographic technology, and has a high-performance electrophotographic photosensitive member in which image defects such as black spots, color spots, and interference fringes hardly occur, and a conductive substrate used therefor It is an object of the present invention to provide an image forming apparatus and an electrophotographic cartridge using the same.

  As a result of intensive studies on the above problems, the present inventors have good electrical characteristics even in different usage environments by managing the particle size of the titanium oxide particles in the undercoat layer within a specific range, such as black spots, color spots, etc. It is possible to form a high-quality image that is extremely unlikely to cause image defects and to produce a high-quality image that is difficult to cause interference fringes when combined with a conductive substrate having a specific range of surface roughness. It was found to form and reached the present invention.

  That is, the gist of the present invention is to provide a subbing layer containing metal oxide particles and a binder resin on a conductive substrate having a maximum surface roughness Rz of 0.8 ≦ Rz ≦ 2 μm, and the subbing layer. In the electrophotographic photosensitive member having a photosensitive layer formed on the layer, the metal oxide particles in a liquid in which the undercoat layer is dispersed in a solvent in which methanol and 1-propanol are mixed at a weight ratio of 7: 3. The electrophotographic photosensitive member is characterized by having a volume average particle diameter of 0.1 μm or less and a cumulative 90% particle diameter of 0.3 μm or less as measured by a dynamic light scattering method. (Claim 1).

At this time, the surface shape of the conductive substrate is preferably formed by cutting (Claim 2).
Further, it is preferable that fine grooves are formed on the surface of the conductive substrate, and the shape of the grooves is curved and discontinuous when the surface of the conductive substrate is developed on a plane.
Furthermore, it is preferable that the grooves formed on the surface of the conductive substrate have a lattice shape.
Further, the kurtosis Rku of the surface of the conductive substrate is 3.5 ≦ Rku ≦ 25, and the groove width L formed on the surface of the conductive substrate is 0.5 μm ≦ L ≦ 6.0 μm. (Claim 5).

Another gist of the present invention is a method for producing a conductive substrate provided in the electrophotographic photosensitive member, wherein a flexible material is brought into contact with the surface of the conductive substrate, and is relative to the surface of the conductive substrate. The present invention resides in a method for manufacturing a conductive substrate.
At this time, it is preferable that the surface of the conductive substrate has been previously subjected to any one of cutting, ironing, grinding, and honing (claims 7 to 10).
The flexible material is preferably a brush (Claim 11), and more preferably a brush formed of a resin kneaded with abrasive grains (Claim 12).

  Still another subject matter of the present invention is an image for forming an electrostatic latent image by performing image exposure on the electrophotographic photosensitive member, the charging means for charging the electrophotographic photosensitive member, and the charged electrophotographic photosensitive member. An image forming apparatus comprising: an exposure unit; a developing unit that develops the electrostatic latent image with toner; and a transfer unit that transfers the toner to a transfer target (claim 13).

  Still another subject matter of the present invention is the above-described electrophotographic photosensitive member, charging means for charging the electrophotographic photosensitive member, and image exposure for performing image exposure on the charged electrophotographic photosensitive member to form an electrostatic latent image. A developing means for developing the electrostatic latent image with toner, a transferring means for transferring the toner to a transfer target, a fixing means for fixing the toner transferred to the transfer target, and an electrophotographic photosensitive member. The electrophotographic cartridge is provided with at least one cleaning unit for collecting the toner.

  According to the present invention, a high-performance electrophotographic photosensitive member in which image defects such as black spots, color spots, interference fringes and the like hardly occur, a conductive substrate used therefor, and an image forming apparatus and an electrophotographic cartridge using the same are provided. can do.

  Hereinafter, embodiments of the present invention will be described in detail. However, the description of the constituent elements described below is a representative example of the embodiments of the present invention, and can be arbitrarily modified without departing from the spirit of the present invention. Can be implemented.

  The electrophotographic photosensitive member of the present invention is constituted by having an undercoat layer containing metal oxide particles and a binder resin on a conductive substrate, and a photosensitive layer formed on the undercoat layer. It is. In the electrophotographic photosensitive member of the present invention, a conductive substrate having a predetermined surface roughness is used, and an undercoat layer containing a metal oxide particle having a predetermined particle size distribution is used. ing.

[I. Conductive substrate]
[I-1. Surface roughness of conductive substrate]
The conductive substrate according to the present invention has a maximum height roughness Rz within a predetermined range, thereby preventing interference fringe defects. Specifically, the conductive substrate according to the present invention has a maximum surface roughness Rz of usually 0.8 μm or more, preferably 1.0 μm or more, more preferably 1.1 μm or more, and usually 2 μm. Hereinafter, it is preferably 1.8 μm or less, more preferably 1.6 μm or less. If the maximum height roughness Rz is too small, the scattered light scattering effect may be insufficient, and if it is too large, defects such as image black spots may easily occur. The maximum height roughness Rz is defined in JIS B 0601: 2001. The surface of the conductive substrate referred to here means at least a part of the surface of the conductive substrate, but usually refers to an image forming region of the conductive substrate.

As long as the surface roughness is the maximum height roughness Rz in the above range, the surface shape of the conductive substrate according to the present invention is not limited, and the method for roughening the surface of the conductive substrate is also available. Is optional.
For example, the groove may be formed in a direction substantially orthogonal to the axis of the conductive substrate. Such grooves are often formed when the surface is roughened by cutting. However, in this case, the reflected light of the writing light to the photoconductor is scattered in a specific plane parallel to the substrate axis, and there is a possibility that the interference fringe suppression effect cannot be sufficiently obtained.

  Therefore, in roughening the surface of the conductive substrate according to the present invention, when the surface of the conductive substrate is spread on the surface of the conductive substrate, a fine groove having a curved and discontinuous shape is obtained. (Hereinafter referred to as “arc-shaped groove” as appropriate) is preferably formed. Here, when the surface of the conductive substrate is developed on a plane, the curved and discontinuous shape means a shape when a groove observed on the surface of the conductive substrate is projected on the plane. Although the fine groove having a shape has a change in depth or the like, the opening exists in the surface of the substrate, and is substantially curved and discontinuous in a plane direction parallel to the surface of the substrate. By using a conductive substrate roughened by an arc-shaped groove, the regularity of the reflected light on the surface of the conductive substrate is disturbed, and interference with the coating film (ie, undercoat layer or photosensitive layer) interface reflected light also occurs. Disturbed. As a result, the interference fringe suppression effect can be increased. In addition, when a straight groove is formed on the surface of the conductive substrate and the surface is roughened, the direction of reflected light scattered by the groove is a specific angular direction, but the groove shape is like an arc groove. The direction of the reflected light scattered by changing the curve to be slightly changed. Furthermore, by making the groove discontinuous, the direction of the reflected light at the groove seam changes. For these reasons, if the surface is roughened by the arc-shaped grooves, the direction of the reflected light on the surface of the conductive substrate becomes complicated, and the effect of suppressing interference fringes is enhanced.

  The arc-shaped grooves are preferably formed in a lattice shape. That is, since a large number of arc-shaped grooves formed on the surface of the conductive substrate are usually formed, a groove pattern formed by a large number of arc-shaped grooves is formed on the surface of the conductive substrate. The pattern is also preferably a lattice. Thereby, since the irregularity of the surface shape of the conductive substrate can be further increased, interference fringes can be more stably prevented.

The index of the surface roughness of the conductive substrate according to the present invention is not limited as long as the maximum height roughness Rz is satisfied, but the following conditions are preferably satisfied.
That is, the kurtosis Rku on the surface of the conductive substrate according to the present invention is usually 3.5 or more, preferably 4.2 or more, more preferably 4.5 or more, and usually 25 or less, preferably 15 or less, more preferably. Is 9 or less. The kurtosis Rku indicates the sharpness of the roughness distribution waveform, and when the kurtosis Rku is within the above range, it is possible to prevent image defects during image formation, and practical production of the conductive substrate. Property is improved. The kurtosis Rku can be measured by the method defined in JIS B 0601: 2001.

  The kurtosis Rku takes a large value when the arcuate grooves are sparse, and tends to become smaller as the surface of the conductive substrate becomes rougher. Although there is a slight difference depending on the processing method, the kurtosis Rku gradually decreases as the roughening progresses, and converges to a value close to 3. For example, when the surface is roughened by a technique such as honing or blasting, the kurtosis Rku is usually about 2.5 to 3 in many cases. Further, when roughening is performed by cutting using a cutting tool, the kurtosis Rku is usually about 2 to 3 due to the formation of serrated irregularities.

When the arc-shaped groove is formed, the groove width L of the arc-shaped groove is usually 0.5 μm or more, preferably 0.6 μm or more, more preferably 0.7 μm or more, and usually 6.0 μm or less. Preferably it is 4.0 micrometers or less, More preferably, it is 3.0 micrometers or less. If the groove width L is too narrow, the productivity of the conductive substrate may be deteriorated. If the groove width L is too wide, the depth of the unevenness on the surface of the conductive substrate also increases, and image defects such as black streaks tend to occur during image formation. May be.
Note that the groove width L is a total of 100 grooves obtained by measuring the groove width of any five of the 20 grooves on the surface of the conductive substrate observed at a magnification of 400 times with an optical microscope. The arithmetic average value of the width values can be measured as the groove width L.

  In particular, the conductive substrate according to the present invention preferably has the above-described maximum height roughness Rz, kurtosis Rku, and groove width L all within the above preferred ranges. That is, the conductive substrate of the present invention has a maximum surface roughness Rz of 0.8 ≦ Rz ≦ 2 μm, a surface kurtosis Rku of 3.5 ≦ Rku ≦ 25, and is formed on the surface. It is particularly preferable that the groove width L is 0.5 ≦ L ≦ 6.0 μm.

[I-2. Configuration of conductive substrate]
As the conductive substrate of the present invention, those used in known electrophotographic photoreceptors can be used. For example, drums, sheets made of metal materials such as aluminum, stainless steel, copper, nickel, etc., laminates of these metal foils, deposits, or conductive layers such as aluminum, copper, palladium, tin oxide, indium oxide on the surface Insulating substrates such as polyester films and papers provided with Furthermore, for example, a plastic film, a plastic drum, paper, a paper tube, and the like obtained by applying a conductive material such as metal powder, carbon black, copper iodide, and a polymer electrolyte together with an appropriate binder resin to conduct the conductive treatment may be used. Also, for example, a plastic sheet or drum that contains a conductive material such as metal powder, carbon black, or carbon fiber and becomes conductive can be used. Moreover, for example, a plastic film or a belt subjected to a conductive treatment with a conductive metal oxide such as tin oxide or indium oxide can also be used.

  Among these, an endless pipe formed of a metal such as aluminum is preferable. In particular, an endless pipe made of aluminum or an aluminum alloy (hereinafter sometimes collectively referred to as aluminum) can be suitably used as the conductive substrate according to the present invention.

[I-3. Method for producing conductive substrate]
The method for producing the conductive substrate according to the present invention by roughening the conductive substrate is arbitrary.
As a general roughening method, for example, there is a method of forming the surface shape of the conductive substrate by cutting with a lathe or the like, and forming irregularities on the surface of the conductive substrate. The maximum height roughness Rz can be realized by this cutting process.

  However, when the surface is roughened by cutting, a slight change in the surface roughness may affect the presence or absence of interference fringes. For this reason, when the surface is roughened by cutting, careful attention should be paid to the maintenance of cutting conditions. Further, in the case of ordinary cutting, continuous grooves with high regularity as described above are often formed in a direction substantially perpendicular to the base axis.

  Therefore, in the method for producing a conductive substrate according to the present invention, as a roughening method, a rough surface is obtained by bringing a flexible material into contact with the surface of the conductive substrate and moving it relative to the surface of the conductive substrate. It is preferable to carry out. Hereinafter, this roughening method will be described.

First, a conductive substrate to be roughened is prepared. The conductive substrate is optional as described above, and among these, an endless pipe made of aluminum or an aluminum alloy is preferable.
There is no restriction | limiting in the shaping | molding method used when shape | molding and manufacturing the said endless pipe. As a forming method, for example, extrusion processing, drawing processing, cutting processing, ironing processing, and the like are known, and a final endless pipe is often formed by combining these processing steps. Usually, cutting and ironing are performed as the final process. Among these, molding by ironing is preferable because of excellent productivity. If the conductive substrate is formed by ironing, the time required for manufacturing the conductive substrate can be greatly reduced as compared to the case of forming by cutting.

  The endless pipe made of aluminum can be used as it is formed by the usual processing method as described above. However, in order to satisfy the mechanical accuracy required for the electrophotographic photosensitive member, before performing the surface roughening, at least the processing (preliminary processing) such as ironing processing, cutting processing, grinding processing, and honing processing is performed in advance. A conductive substrate obtained by a technique of processing the surface to a predetermined surface roughness (the above-mentioned maximum height roughness Rz) after forming irregularities on the surface of the conductive substrate to some extent by performing one is preferable. .

Also, when using a conductive substrate other than an aluminum endless pipe, the pre-processing is performed in advance, and after forming irregularities on the surface of the conductive substrate to some extent, the arc-shaped groove is formed. preferable. By performing such pre-processing, the productivity of the conductive substrate is improved. In other words, depending on the type of pretreatment, it is possible to form continuous or intermittent grooves extending in the axial direction, circumferential direction, etc. on the surface of the conductive substrate. Can be made more irregular as compared with the case where only the arc-shaped groove is formed, and it is possible to obtain a better interference fringe suppression effect.
Of the processes performed at the time of forming the conductive substrate, the molding process such as the ironing process and the cutting process also acts as the preliminary process.

  When a conductive substrate is prepared, an arc-shaped groove is formed by bringing a flexible material into contact with the surface of the conductive substrate as a rubbing material and relatively moving it. When the rubbing material is deformed at the contact site, the rubbing speed changes from the start to the end of the contact, so that the groove shape becomes a curve. In a conductive substrate having a curved surface that is generally used, the groove shape is a curve unless the conductive substrate and the rotating shaft of the rubbing material are in contact with each other in parallel. That is, when forming the arc-shaped groove according to the present invention, the conductive base and the rotational axis of the rubbing material are in a non-parallel positional relationship.

Examples of the flexible material include, but are not limited to, rubber, resin, sponge, brush, cloth, and non-woven fabric. Further, in order to increase the generation efficiency of the arc-shaped grooves, those obtained by putting abrasive grains in these flexible materials are preferable, and in particular, a brush formed of a resin kneaded with abrasive grains is more preferable.
When a grindstone having little flexibility is used as the rubbing material, there may be a site where the surface of the conductive substrate is deeply damaged. Although the grooves can be made shallow by using fine abrasive grains, in this case, not only the productivity is lowered, but the grindstone may be clogged. Aluminum or an alloy thereof may be used as the conductive substrate. However, clogged grinding powder is likely to be transferred to the surface of soft aluminum or an alloy thereof, and thus easily becomes a foreign matter defect. In addition, since the grindstone hardly deforms at the contact portion, the groove length is often short and linear.

  As the brush to be used, those in which abrasive grains are kneaded into a resin such as nylon are preferable. Generally used grinding brushes mainly use the grinding force at the tip of the brush material (so-called “brush hair”), but with brushes containing abrasive grains, grinding is performed at the body of the brush material. Can be used effectively. For this reason, the contact portion can be widened, the productivity is increased, and further, the elasticity of the brush is utilized, and gentle grinding can be performed while the unevenness is not excessively increased and the removal amount is reduced. In addition, clogging is less likely to occur due to the constantly changing flexibility and contact portion of the brush material. Taking advantage of this feature, it is possible to use abrasive grains with a small particle size that cannot be used due to clogging when grinding wheels, and the surface roughness can be easily kept low, so images other than interference fringes can be used. Highly effective against defects. Furthermore, the high irregularity of the arc-shaped grooves to be formed also has a high effect on interference fringe suppression.

  Further, the above-described maximum height roughness Rz, kurtosis Rku and groove width L are the properties of the brush material used, such as the length, hardness, implantation density, particle size of abrasive grains kneaded into the brush, and the brush And the processing conditions such as the time for which the brush is brought into contact with the conductive substrate.

  Among these, the maximum height roughness Rz is greatly influenced by the grain size of the abrasive grains kneaded into the brush, and when the grain size is large, Rz is large, and when the grain size is small, Rz is also small. Tend. For this reason, the grain size of the abrasive grains is usually 1 μm or more, preferably 5 μm or more, and usually 50 μm or less, preferably 35 μm or less.

  Further, the kurtosis Rku is related to the frequency with which the brush contacts the conductive substrate, and varies particularly depending on the number of rotations of the brush, the processing time between the brush and the conductive substrate, and the number of times of surface roughening treatment with the brush. Usually, the kurtosis Rku is large at the beginning of the process and decreases as the process proceeds. Therefore, when the kurtosis Rku in the middle of the process is measured and the process is completed when the kurtosis Rku is within the above-mentioned preferred range, a conductive substrate having a desired arc-shaped groove can be obtained.

  Furthermore, the conditions for performing the roughening treatment may be constant or may be changed. In particular, if processing under different conditions is performed a plurality of times, the arc-shaped grooves can be formed in a lattice shape, which is preferable.

  By the way, it is generally known that fine burrs are generated when irregularities are formed on the surface of a conductive substrate by cutting, grinding, honing or the like. When the undercoat layer or the photosensitive layer is formed on the conductive substrate, this burr is locally formed with a thin portion of the undercoat layer or the photosensitive layer. It often causes image defects such as black lines. However, as described above, the burrs on the surface of the conductive substrate are removed by bringing the flexible material into contact with the surface of the conductive substrate as a rubbing material and moving it relatively. Therefore, according to the roughening method of the conductive substrate of the present invention, even if burrs are generated by the pretreatment, the quality of the conductive substrate is not finally deteriorated.

Hereinafter, the roughening method described above will be specifically described with reference to examples.
FIG. 1 is a schematic diagram for explaining an example of a method for roughening a conductive substrate. The conductive substrate 1 is rotatably held by the inner expanding and holding mechanism 2 and is rotated around a shaft (hereinafter referred to as “substrate shaft”) 1A as the inner expanding and holding mechanism 2 rotates. Yes.

  The wheel-like brush 3 which is a rubbing material made of a flexible material is movable and rotatable around a shaft (hereinafter referred to as “brush shaft”) 3A so that the brush material contacts the conductive substrate 1. It arrange | positions so that it may be possible. Thus, the brush 3 can move relative to the conductive substrate 1 while rotating about the brush shaft 3A. The moving direction of the brush 3 is arbitrary as long as the portion corresponding to the image forming region on the surface of the conductive substrate 1 can come into contact with the brush 3, but is usually parallel to the axial direction of the conductive substrate 1 (in FIG. 1). Move up and down).

  In the case of the wheel-like brush 3 as in this example, the rotation axis of the brush 3 (usually the brush axis 3A) is not parallel to the conductive substrate 1 in order to form an arc-shaped groove (see FIGS. 2 and 3). It is preferable to have a relationship. That is, the rotation axis of the brush 3 (that is, the brush shaft 3A) is the conductive substrate in order to prevent machining unevenness due to the inclination of the rotation shaft between the conductive substrate 1 and the brush 3 and uneven contact due to brush uneven wear. It is preferable to set a position (twist position) that is not on the same plane with respect to one base axis 1A.

  This is because it is difficult to form a curved and discontinuous arc-shaped groove when the base shaft 1A and the brush shaft 3A are parallel. Further, in this case, non-uniformity of polishing force (particularly, non-uniformity in the direction of the brush shaft 3A) occurs in the brush 3 due to the difference in length and density of the brush material, and the non-uniformity is directly conducted. This is because the surface of the conductive substrate 1 is transferred to the surface of the conductive substrate 1, so that the polished state of the surface of the conductive substrate 1 is also non-uniform in the axial direction and unevenness may occur.

  Note that the local processing unevenness is improved by the technique of relatively swinging the brush 3 or the conductive substrate 1 in the axial direction as disclosed in JP-A-9-114118. Processing unevenness may occur when viewed in the entire axial direction of the conductive substrate 1.

  When the arc-shaped groove is formed in the configuration as in this example, the brush 3 is brought into contact with the surface of the conductive substrate 1 and the brush 3 is moved in the axial direction of the conductive substrate 1 while rotating the brush 3. At this time, the conductive substrate 1 is also rotated about the substrate axis 1A. In FIG. 1, the rotation directions of the conductive substrate 1 and the brush 3 are indicated by arrows.

  As a result, the brush 3 comes into contact with the conductive substrate 1 while being elastically deformed, so that an arc-shaped groove is formed on the surface of the conductive substrate 1. In particular, as shown in FIG. 1, when the base shaft 1A and the brush shaft 3A are arranged so as to be substantially orthogonal, the conductive base 1 is set by setting the rotational speed of the brush 3 low and the contact margin small. When unfolded, an oblique arc-shaped groove as shown in FIG. 2 is formed. On the other hand, when the rotation speed of the brush 3 is increased and the contact allowance is increased, an oblique grid-like arc-shaped groove as shown in FIG. 3 is formed. When both are compared, it is more preferable to increase the rotation speed of the brush 3 and to increase the contact allowance, because the productivity increases.

  Further, the relative movement of the brush 3 with respect to the conductive substrate 1 is usually sufficient once, but may be performed a plurality of times. When moving a plurality of times, it may always move in one direction or may reciprocate relatively.

  In this example, the wheel-like brush 3 is used, but the shape of the brush is not limited. For example, a cup-shaped brush 4 as shown in FIG. 4 may be used. When the cup-shaped brush 4 is used, both the shafts 1A and 4A may be on the same plane as long as the brush shaft 4A is not parallel to the base shaft 1A. In FIG. 4, the parts indicated by the same reference numerals as those in FIG. 1 are the same as those in FIG.

  Moreover, when using the wheel-shaped brush 3 as shown in FIG. 1, there is no restriction | limiting in the structure of the wheel-shaped brush 3. FIG. Therefore, the brush material may be staggered in the conductive substrate 1, but in order to further increase the implantation density, a material constituted by a method such as winding the channel brush 4 around the shaft material is preferable.

  Further, a plurality of brushes 3 may be used as shown in FIG. The productivity is improved by using a plurality of brushes 3, and the surface of the conductive substrate 1 can be made into a rough surface with a more complicated shape by changing the rotation conditions of each brush 3. Therefore, the interference fringe suppression effect is also achieved. It is further improved. In FIG. 5, parts indicated by the same reference numerals as those in FIG. 1 are the same as those in FIG. 1.

  Incidentally, polishing powder (for example, powder of the conductive substrate 1 that has been shaved) may remain on the surface of the conductive substrate 1. Further, when the brush 3 contains abrasive grains, the abrasive grains may be detached from the brush 3 and remain on the surface of the conductive substrate 1. Therefore, when the surface is roughened, in order to remove fine particles such as abrasive powder and abrasive grains detached from the brush 3 from the surface of the conductive substrate 1, a cleaning liquid is applied or immersed in the cleaning liquid. It is preferable to do. There is no limitation on the cleaning liquid, and various organic and aqueous cleaning agents can be used. In order to prevent adsorption of fine particles, ammonia-added water used in semiconductor cleaning can also be used.

  Further, since the new surface is exposed on the surface of the conductive substrate 1 due to the roughening, when the undercoat layer is not formed immediately after the roughening, the processing oil is used instead of the cleaning liquid in order to prevent surface corrosion. It is also possible to protect the surface of the conductive substrate 1 by roughening the surface. In such a case, it is preferable to perform finishing cleaning after the surface roughening and before the formation of the undercoat layer, and further, the surface roughening step is incorporated in the cleaning step of the conductive substrate before the formation of the undercoat layer. It is more preferable to increase productivity. For example, as shown in FIG. 6, by incorporating a roughening brush 3 directly under the cleaning brush 5, it is possible to perform strong physical cleaning immediately after the roughening, and the surface state of the conductive substrate 1 is cleaned. It is possible to roughen the surface while maintaining a stable state. In FIG. 6, parts indicated by the same reference numerals as those in FIG. 1 are the same as those in FIG.

  Further, here, the brush 3 is moved relative to the conductive substrate 1 by moving the brush 3, but the brush 3 is moved relative to the conductive substrate 1 by moving the conductive substrate 1. You may make it move relatively. Alternatively, the brush 3 may move relative to the conductive substrate 1 by moving both the conductive substrate 1 and the brush 3.

[I-4. Other matters regarding conductive substrate]
When a metal material such as an aluminum alloy is used as the conductive substrate, an anodized one may be used. When the anodizing treatment is performed, it is desirable to perform a sealing treatment by a known method.

[II. Undercoat layer]
The undercoat layer is a layer containing metal oxide particles and a binder resin. The undercoat layer may contain other components as long as the effects of the present invention are not significantly impaired.
The undercoat layer according to the present invention is provided between the conductive substrate and the photosensitive layer, improves the adhesion between the conductive substrate and the photosensitive layer, conceals the dirt and scratches on the conductive substrate, impurities and the surface. At least one of functions such as prevention of carrier injection due to non-uniform physical properties, improvement of non-uniformity of electrical characteristics, prevention of lowering of surface potential due to repeated use, and prevention of local surface potential fluctuations that cause image quality defects It is a layer that has one and is not essential for the development of photoelectric characteristics.

[II-1. Metal oxide particles]
[II-1-1. Types of metal oxide particles]
As the metal oxide particles according to the present invention, any metal oxide particles that can be used for an electrophotographic photoreceptor can be used.
Specific examples of metal oxides forming the metal oxide particles include metal oxides containing one metal element such as titanium oxide, aluminum oxide, silicon oxide, zirconium oxide, zinc oxide and iron oxide; calcium titanate And metal oxides containing a plurality of metal elements such as strontium titanate and barium titanate. Among these, metal oxide particles made of a metal oxide having a band gap of 2 to 4 eV are preferable. If the band gap is too small, carrier injection from the conductive substrate is likely to occur, and image defects such as black spots and color spots are likely to occur. Moreover, if the band gap is too large, the charge transfer is hindered by the trapping of electrons, and the electrical characteristics may be deteriorated.

  As the metal oxide particles, only one type of particles may be used, or a plurality of types of particles may be used in any combination and ratio. In addition, the metal oxide particles may be formed from only one kind of metal oxide, or may be formed by using two or more kinds of metal oxides in any combination and ratio. good.

  Among the metal oxides forming the metal oxide particles, titanium oxide, aluminum oxide, silicon oxide and zinc oxide are preferable, titanium oxide and aluminum oxide are more preferable, and titanium oxide is particularly preferable.

  The crystal form of the metal oxide particles is arbitrary as long as the effects of the present invention are not significantly impaired. For example, the crystal form of metal oxide particles using titanium oxide as a metal oxide (that is, titanium oxide particles) is not limited, and any of rutile, anatase, brookite, and amorphous can be used. Further, the crystal form of the titanium oxide particles may include those in a plurality of crystal states from those having different crystal states.

Further, the surface of the metal oxide particles may be subjected to various surface treatments. For example, treatment with a treating agent such as 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 organic silicon compound may be performed.
In particular, when titanium oxide particles are used as the metal oxide particles, the surface treatment is preferably performed with an organosilicon compound. Examples of the organosilicon compound include silicone oils such as dimethylpolysiloxane and methylhydrogenpolysiloxane; organosilanes such as methyldimethoxysilane and diphenyldimethoxysilane; silazanes such as hexamethyldisilazane; vinyltrimethoxysilane and γ-mercaptopropyl. Examples thereof include silane coupling agents such as trimethoxysilane and γ-aminopropyltriethoxysilane.

The metal oxide particles are particularly preferably treated with a silane treating agent represented by the structure of the following formula (i). This silane treatment agent is a good treatment agent with good reactivity with metal oxide particles.

In the formula (i), R ¹ and R ² each independently represents an alkyl group. The carbon number of R ¹ and R ² is not limited, but is usually 1 or more, and usually 18 or less, preferably 10 or less, more preferably 6 or less. Examples of suitable R ¹ and R ² include a methyl group and an ethyl group.
In the formula (i), R ³ represents an alkyl group or an alkoxy group. There is no limitation on the number of carbon atoms in R ^3, usually 1 or more and usually 18 or less, preferably 10 or less, more preferably 6 or less. Examples of suitable R ³ include methyl group, ethyl group, methoxy group, and ethoxy group.
Reactivity or decrease in the number of carbon atoms of R ¹ to R ³ is too large and the metal oxide particles, the dispersion stability in the coating liquid for forming an undercoat layer of the metal oxide particles after treatment is reduced there is a possibility.

  In addition, the outermost surface of these surface-treated metal oxide particles is usually treated with the treatment agent as described above. At this time, the surface treatment described above may be performed only by one surface treatment, or two or more surface treatments may be performed in any combination. For example, it may be treated with a treatment agent such as aluminum oxide, silicon oxide or zirconium oxide before the surface treatment with the silane treatment agent represented by the above formula (i). Moreover, you may use together the metal oxide particle which performed different surface treatment in arbitrary combinations and a ratio.

Among the metal oxide particles according to the present invention, examples of those that have been commercialized will be given. However, the metal oxide particles according to the present invention are not limited to the products exemplified below.
Examples of specific products of titanium oxide particles include ultrafine titanium oxide “TTO-55 (N)” that has not been surface-treated; ultrafine titanium oxide “TTO-55 (A) coated with Al ₂ O _3. ) ”,“ TTO-55 (B) ”; ultrafine titanium oxide surface treated with stearic acid“ TTO-55 (C) ”; ultrafine titanium oxide surface treated with Al ₂ O ₃ and organosiloxane “TTO-55 (S)”; high purity titanium oxide “CR-EL”; sulfuric acid method titanium oxide “R-550”, “R-580”, “R-630”, “R-670”, “R-” 680 "," R-780 "," A-100 "," A-220 "," W-10 "; chlorinated titanium oxides" CR-50 "," CR-58 "," CR-60 "," CR-60-2 "," CR-67 "; conductive titanium oxide" SN " -100P "," SN-100D "," ET-300W "; (above, manufactured by Ishihara Sangyo Co., Ltd.). In addition, titanium oxides such as “R-60”, “A-110”, and “A-150”; and “SR-1”, “R-GL”, “R—” coated with Al ₂ O ₃ 5N "," R-5N-2 "," R-52N "," RK-1 "," a-SP "; subjected to SiO _2, Al ₂ O ₃ coating" R-GX "," R-7E _{"; ZnO, SiO 2, Al 2} O 3 coating was subjected to a" R-650 "; subjected to ZrO _2, Al ₂ O ₃ coating" R-61N "; (or, manufactured by Sakai Chemical Industry Co., Ltd.) also like Can be mentioned. Furthermore, surface-treated with SiO _2, Al ₂ O ₃ "TR-700"; ZnO, surface-treated with SiO _2, Al ₂ O ₃ "TR-840", another "TA-500", "TA Surface-untreated titanium oxide such as “-100”, “TA-200”, “TA-300”; “TA-400” (manufactured by Fuji Titanium Industry Co., Ltd.); surface-treated with Al ₂ O ₃ ; surface not subjected to treatment, "MT-150 W", "MT-500B"; surface-treated with SiO _2, Al ₂ O ₃ "MT-100SA", "MT-500SA"; SiO _2, Al ₂ O ₃ and organosiloxane Examples thereof include “MT-100SAS” and “MT-500SAS” (manufactured by Teika Co., Ltd.) surface-treated with siloxane.

Examples of specific products of aluminum oxide particles include “Aluminium Oxide C” (manufactured by Nippon Aerosil Co., Ltd.).
Furthermore, examples of specific products of silicon oxide particles include “200CF”, “R972” (manufactured by Nippon Aerosil Co., Ltd.), “KEP-30” (manufactured by Nippon Shokubai Co., Ltd.), and the like.
Moreover, "SN-100P" (made by Ishihara Sangyo Co., Ltd.) etc. are mentioned as an example of the specific goods of a tin oxide particle.
Furthermore, “MZ-305S” (manufactured by Teika Co., Ltd.) and the like are listed as examples of specific products of zinc oxide particles.

[II-1-2. Physical properties of metal oxide particles]
About the metal oxide particle which concerns on this invention, the following requirements are materialized regarding the particle size distribution. That is, the metal oxidation in a liquid (hereinafter referred to as “dispersion for measuring the undercoat layer” as appropriate) in which the undercoat layer according to the present invention is dispersed in a solvent in which methanol and 1-propanol are mixed at a weight ratio of 7: 3. The volume average particle diameter measured by the dynamic light scattering method of physical particles is 0.1 μm or less, and the cumulative 90% particle diameter is 0.3 μm or less.
Hereinafter, this point will be described in detail.

[Volume average particle diameter of metal oxide particles]
The metal oxide particles according to the present invention have a volume average particle size of 0.1 μm or less, preferably 95 nm or less, more preferably 90 nm or less, measured by a dynamic light scattering method in the undercoat layer measurement dispersion. is there. Moreover, although there is no restriction | limiting in the minimum of the said volume average particle diameter, Usually, it is 20 nm or more. By satisfying the above range, the electrophotographic photosensitive member of the present invention has stable exposure-charging repetition characteristics under low temperature and low humidity, and suppresses occurrence of image defects such as black spots and color spots in the obtained image. it can.

[About cumulative 90% particle size of metal oxide particles]
The metal oxide particles according to the present invention have a cumulative 90% particle diameter measured by a dynamic light scattering method in a dispersion for measuring an undercoat layer of 0.3 μm or less, preferably 0.25 μm or less, more preferably 0.2 μm or less. The lower limit of the cumulative 90% particle size is not limited, but is usually 10 nm or more, preferably 20 nm or more, more preferably 50 nm or more. In a conventional electrophotographic photoreceptor, a metal oxide particle aggregate that is coarse enough to penetrate the front and back of the undercoat layer is formed by aggregation of metal oxide particles in the undercoat layer. There was a possibility that defects would occur during image formation due to the aggregates of product particles. Further, when a contact type is used as the charging means, when the photosensitive layer is charged, the charge moves from the photosensitive layer to the conductive support through the metal oxide particles, and the charging is appropriately performed. There was also a possibility that it could not be done. However, in the electrophotographic photosensitive member of the present invention, since the cumulative 90% particle diameter is very small, there are very few large metal oxide particles that cause defects as described above. As a result, in the electrophotographic photosensitive member of the present invention, it is possible to suppress the occurrence of defects and the inability to appropriately charge, and high-quality image formation is possible.

[Measurement method of volume average particle size and cumulative 90% particle size]
The volume average particle size and the cumulative 90% particle size of the metal oxide particles according to the present invention are a mixed solvent in which an undercoat layer is mixed with methanol and 1-propanol at a weight ratio of 7: 3 (this is a particle size). Prepare a dispersion for measuring the undercoat layer by dispersing in a dispersion medium for measurement), and measure the particle size distribution of the metal oxide particles in the dispersion for measuring the undercoat layer by the dynamic light scattering method. Is a value obtained by

  In the dynamic light scattering method, the speed of Brownian motion of finely dispersed particles is detected, and the particle size distribution is detected by irradiating the particles with laser light and detecting light scattering (Doppler shift) with different phases according to the speed. Is what you want. The values of the volume average particle diameter and the cumulative 90% particle diameter of the metal oxide particles in the undercoat layer measurement dispersion are obtained when the metal oxide particles are stably dispersed in the undercoat layer measurement dispersion. It is a value and does not mean the particle size in the undercoat layer after the undercoat layer is formed. In the actual measurement, the volume average particle size and the cumulative 90% particle size are specifically expressed by a dynamic light scattering particle size analyzer (MICROTRAC UPA model: 9340-UPA, manufactured by Nikkiso Co., Ltd., hereinafter referred to as UPA). ) And the following settings. A specific measurement operation is performed based on the instruction manual of the particle size analyzer (manufactured by Nikkiso Co., Ltd., Document No. T15-490A00, revised No. E).

・ Setting of dynamic light scattering system particle size analyzer Upper limit of measurement: 5.9978 μm
Measurement lower limit: 0.0035 μm
Number of channels: 44
Measurement time: 300 sec.
Particle permeability: Absorption Particle refractive index: N / A (not applicable)
Particle shape: non-spherical density: 4.20 g / cm ³ (*)
Dispersion medium type: Methanol / 1-propanol = 7/3
Dispersion medium refractive index: 1.35
(*) The value of density is for titanium dioxide particles, and for other particles, the values described in the instruction manual are used.

The amount of the mixed solvent of methanol and 1-propanol (weight ratio: methanol / 1-propanol = 7/3; refractive index = 1.35) used as the dispersion medium is the dispersion for measuring the undercoat layer as the sample. The amount of the sample concentration index (SIGNAL LEVEL) of the liquid is 0.6 to 0.8.
The measurement of particle size by dynamic light scattering is performed at 25 ° C.

  The volume average particle diameter and cumulative 90% particle diameter of the metal oxide particles according to the present invention are 100% of the total volume of the metal oxide particles when the particle size distribution is measured by the dynamic light scattering method as described above. When the cumulative curve of the volume particle size distribution is obtained from the small particle size side by the dynamic light scattering method described above, the particle diameter at the point where the cumulative curve becomes 50% is the volume average particle diameter (center diameter: median diameter). And the particle diameter at the point where the cumulative curve is 90% is defined as the cumulative 90% particle diameter.

[Other physical properties]
There is no restriction | limiting in the average primary particle diameter of the metal oxide particle concerning this invention, and it is arbitrary unless the effect of this invention is impaired remarkably. However, the average primary particle diameter of the metal oxide particles according to the present invention is usually 1 nm or more, preferably 5 nm or more, and usually 100 nm or less, preferably 70 nm or less, more preferably 50 nm or less.
The average primary particle diameter can be obtained by an arithmetic average value of particle diameters directly observed by a transmission electron microscope (hereinafter referred to as “TEM” as appropriate).

Moreover, there is no restriction | limiting in the refractive index of the metal oxide particle which concerns on this invention, What kind of thing can be used if it can be used for an electrophotographic photoreceptor. The refractive index of the metal oxide particles according to the present invention is usually 1.3 or more, preferably 1.4 or more, and usually 3.0 or less, preferably 2.9 or less, more preferably 2.8 or less. .
In addition, the literature value described in various publications can be used for the refractive index of a metal oxide particle. For example, according to the filler utilization dictionary (Filler Study Group, Taiseisha, 1994), it is as shown in Table 1 below.

  In the undercoat layer of the present invention, the use ratio of the metal oxide particles and the binder resin is arbitrary as long as the effects of the present invention are not significantly impaired. However, in the undercoat layer of the present invention, the metal oxide particles are usually 0.5 parts by weight or more, preferably 0.7 parts by weight or more, more preferably 1.0 parts by weight with respect to 1 part by weight of the binder resin. Part or more, and usually 8 parts by weight or less, preferably 4 parts by weight or less, more preferably 3.8 parts by weight or less, particularly preferably 3.5 parts by weight or less. If the amount of the metal oxide particles is too small relative to the binder resin, the electrical characteristics of the obtained electrophotographic photoreceptor may deteriorate, particularly the residual potential may increase, and if too large, the electrophotographic photoreceptor is formed using the electrophotographic photoreceptor. There is a possibility that image defects such as black spots and color spots increase in the image.

[II-2. Binder resin]
Any binder resin can be used as the binder resin used in the undercoat layer of the present invention as long as the effects of the present invention are not significantly impaired. Usually, it is soluble in a solvent such as an organic solvent, and the undercoat layer is insoluble or low in solubility in a solvent such as an organic solvent used in a coating solution for forming a photosensitive layer. Use one that does not mix.

  As such a binder resin, for example, a resin such as phenoxy, epoxy, polyvinyl pyrrolidone, polyvinyl alcohol, casein, polyacrylic acid, cellulose, gelatin, starch, polyurethane, polyimide, polyamide or the like is cured alone or with a curing agent. Can be used in Of these, polyamide resins such as alcohol-soluble copolymerized polyamides and modified polyamides are preferable because they exhibit good dispersibility and coating properties.

  As the polyamide resin, for example, so-called copolymer nylon obtained by copolymerizing 6-nylon, 66-nylon, 610-nylon, 11-nylon, 12-nylon, etc .; N-alkoxymethyl-modified nylon, N-alkoxyethyl-modified Examples thereof include alcohol-soluble nylon resins such as a type in which nylon is chemically modified, such as nylon. Specific products include, for example, “CM4000”, “CM8000” (manufactured by Toray), “F-30K”, “MF-30”, “EF-30T” (manufactured by Nagase Chemtech Co., Ltd.), and the like. .

Among these polyamide resins, a copolymerized polyamide resin containing a diamine component corresponding to the diamine represented by the following formula (ii) (hereinafter, appropriately referred to as “diamine component corresponding to formula (ii)”) as a constituent component is particularly preferable. Used.

In the formula (ii), R ^{4 to} R ⁷ represent a hydrogen atom or an organic substituent. m and n each independently represents an integer of 0 to 4. In addition, when there are a plurality of substituents, these substituents may be the same as or different from each other.

When the example of a suitable thing as an organic substituent represented by R < ⁴ > -R < ⁷ > is given, the hydrocarbon group which may contain the hetero atom is mentioned. Among these, preferred are, for example, alkyl groups such as methyl group, ethyl group, n-propyl group and isopropyl group; alkoxy groups such as methoxy group, ethoxy group, n-propoxy group and isopropoxy group; phenyl group and naphthyl group And aryl groups such as an anthryl group and a pyrenyl group, more preferably an alkyl group or an alkoxy group. Particularly preferred are a methyl group and an ethyl group.
Although the carbon number of the organic substituent represented by R ⁴ to R ⁷ are arbitrary unless significantly impairing the effects of the present invention, usually 20 or less, preferably 18 or less, more preferably 12 or less, and usually 1 or more. If the number of carbon atoms is too large, the solubility in the solvent deteriorates when preparing the coating solution for forming the undercoat layer, and even if it can be dissolved, the storage stability as the coating solution for forming the undercoat layer deteriorates. Show a tendency to

  The copolymerized polyamide resin containing a diamine component corresponding to the formula (ii) as a constituent component constitutes a constituent component other than the diamine component corresponding to the formula (ii) (hereinafter simply referred to as “other polyamide constituent component”). It may be included as a unit. Examples of other polyamide constituents include lactams such as γ-butyrolactam, ε-caprolactam, lauryllactam; 1,4-butanedicarboxylic acid, 1,12-dodecanedicarboxylic acid, 1,20-eicosanedicarboxylic acid, and the like. Dicarboxylic acids; diamines such as 1,4-butanediamine, 1,6-hexamethylenediamine, 1,8-octamethylenediamine, 1,12-dodecanediamine; piperazine and the like. At this time, examples of the copolymerized polyamide resin include those obtained by copolymerizing the constituent components into, for example, binary, ternary, and quaternary.

  When the copolymerized polyamide resin containing the diamine component corresponding to the formula (ii) as a constituent component contains other polyamide constituent components as constituent units, the proportion of the diamine component corresponding to the formula (ii) in all the constituent components Although there is no limitation, it is usually 5 mol% or more, preferably 10 mol% or more, more preferably 15 mol% or more, and usually 40 mol% or less, preferably 30 mol% or less. If the amount of the diamine component corresponding to formula (ii) is too large, the stability of the coating solution for forming the undercoat layer may be deteriorated, and if it is too small, the change in the electrical properties under high temperature and high humidity conditions will increase. May be less stable against environmental changes.

  Specific examples of the copolymerized polyamide resin are shown below. However, in specific examples, the copolymerization ratio represents the charge ratio (molar ratio) of the monomer.

There is no restriction | limiting in particular in the manufacturing method of said copolyamide, The normal polycondensation method of polyamide is applied suitably. For example, a polycondensation method such as a melt polymerization method, a solution polymerization method, and an interfacial polymerization method can be appropriately applied. In the polymerization, for example, a monobasic acid such as acetic acid or benzoic acid; a monoacid base such as hexylamine or aniline may be contained in the polymerization system as a molecular weight regulator.
In addition, binder resin may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.

  Moreover, there is no restriction | limiting also in the number average molecular weight of binder resin which concerns on this invention. For example, when a copolymerized polyamide is used as the binder resin, the number average molecular weight of the copolymerized polyamide is usually 10,000 or more, preferably 15000 or more, and usually 50000 or less, preferably 35000 or less. If the number average molecular weight is too small or too large, it is difficult to maintain the uniformity of the undercoat layer.

[II-3. Other ingredients]
The undercoat layer of the present invention may contain components other than the metal oxide particles, the binder resin, and the solvent described above as long as the effects of the present invention are not significantly impaired. For example, the undercoat layer may contain additives as other components.

  Examples of additives include sodium phosphite, sodium hypophosphite, phosphorous acid, heat stabilizers typified by hypophosphorous acid and hindered phenol, other polymerization additives, and antioxidants. It is done. In addition, an additive may be used individually by 1 type and may use 2 or more types together by arbitrary combinations and a ratio.

[II-4. Physical properties of undercoat layer]
[Film thickness]
The thickness of the undercoat layer is arbitrary, but is usually 0.1 μm or more, preferably 0.3 μm or more, more preferably 0 from the viewpoint of improving the photoreceptor characteristics and coating properties of the electrophotographic photoreceptor of the present invention. It is preferably in the range of 5 μm or more, usually 20 μm or less, preferably 15 μm or less, more preferably 10 μm or less.

〔Surface roughness〕
The surface layer of the undercoat layer according to the present invention is not limited in its surface shape, but is usually in-plane root mean square roughness (RMS), in-plane arithmetic average roughness (Ra), in-plane maximum roughness (P− V). These numerical values are numerical values obtained by extending the reference length of the root mean square height, arithmetic average height, and maximum height in the standard of JIS B 0601: 2001 to the reference plane, and the height on the reference plane. Using Z (x) which is the value of the direction, the in-plane root mean square roughness (RMS) is the root mean square of Z (x), and the in-plane arithmetic mean roughness (Ra) is Z (x) The average of the absolute values, the in-plane maximum roughness (P-V) represents the sum of the maximum value of the peak height of Z (x) and the maximum value of the valley depth, respectively.

The in-plane root mean square roughness (RMS) of the undercoat layer according to the present invention is usually in the range of 10 nm or more, preferably 20 nm or more, and usually 100 nm or less, preferably 50 nm or less. If the in-plane root mean square roughness (RMS) is too small, the adhesiveness with the upper layer may be deteriorated, and if it is too large, the uniformity of the coating film thickness of the upper layer may be deteriorated.
The in-plane arithmetic average roughness (Ra) of the undercoat layer according to the present invention is usually in the range of 10 nm or more and usually 50 nm or less. If the in-plane arithmetic average roughness (Ra) is too small, the adhesion with the upper layer may be deteriorated, and if it is too large, the uniformity of the coating thickness of the upper layer may be deteriorated.
The in-plane maximum roughness (P-V) of the undercoat layer according to the present invention is usually in the range of 100 nm or more, preferably 300 nm or more, and usually 1000 nm or less, preferably 800 nm or less. If the in-plane maximum roughness (PV) is too small, the adhesion with the upper layer may be deteriorated, and if it is too large, the uniformity of the coating thickness of the upper layer may be deteriorated.

  In addition, the numerical value of the index (RMS, Ra, PV) relating to the surface shape can be any surface as long as it is measured by a surface shape analyzer capable of measuring irregularities in the reference plane with high accuracy. Although it may be measured by a shape analyzer, it is preferably measured by a method of detecting irregularities on the sample surface by combining a high-accuracy phase shift detection method and interference fringe order counting using an optical interference microscope. More specifically, it is preferable to measure in the wave mode by the interference fringe addressing method using Micromap of Ryoka System Co., Ltd.

[Absorbance when used as dispersion]
The undercoat layer according to the present invention is dispersed in a solvent capable of dissolving the binder resin binding the undercoat layer to form a dispersion (hereinafter referred to as “absorbance measurement dispersion” as appropriate). Usually, the absorbance of the dispersion exhibits specific physical properties.

  The absorbance of the dispersion for absorbance measurement can be measured by a generally known spectrophotometer. Conditions such as cell size and sample concentration when measuring absorbance vary depending on physical properties such as the particle diameter and refractive index of the metal oxide particles to be used. Therefore, in general, in the wavelength region to be measured (in the present invention, (400 nm to 1000 nm), the sample concentration is appropriately adjusted so as not to exceed the measurement limit of the detector.

  A cell size (optical path length) for measurement is 10 mm. Any cell may be used as long as it is substantially transparent in the range of 400 nm to 1000 nm, but it is preferable to use a quartz cell, and in particular, a sample cell and a standard cell. It is preferable to use a matched cell that has a difference in transmittance characteristics within a specific range.

  When the undercoat layer according to the present invention is dispersed to obtain a dispersion for measuring absorbance, the binder resin that binds the undercoat layer is not substantially dissolved, and is formed on the undercoat layer. After dissolving and removing the layer on the undercoat layer with a solvent capable of dissolving the layer and the like, the binder resin for binding the undercoat layer is dissolved in the solvent to obtain a dispersion for absorbance measurement. At this time, as a solvent that can dissolve the undercoat layer, a solvent that does not have large light absorption in a wavelength region of 400 nm to 1000 nm may be used.

  Specific examples of the solvent that can dissolve the undercoat layer include alcohols such as methanol, ethanol, 1-propanol, and 2-propanol, and particularly methanol, ethanol, and 1-propanol. Moreover, these may be used individually by 1 type and may use 2 or more types together by arbitrary combinations and a ratio.

In particular, an absorbance measurement dispersion in which the undercoat layer according to the present invention is dispersed in a solvent in which methanol and 1-propanol are mixed at a weight ratio of 7: 3, with respect to the light with a wavelength of 400 nm and the light with a wavelength of 1000 nm. The difference from the absorbance (absorbance difference) is as follows. That is, the absorbance difference is usually 0.3 (Abs) or less, preferably 0.2 (Abs) or less, when the refractive index of the metal oxide particles is 2.0 or more. Moreover, when the refractive index of a metal oxide particle is less than 2.0, it is 0.02 (Abs) or less normally, Preferably it is 0.01 (Abs) or less.
The absorbance value depends on the solid content concentration of the liquid to be measured. For this reason, when measuring the absorbance, it is preferable to disperse so that the concentration of the metal oxide particles in the dispersion is in the range of 0.003% to 0.0075% by weight.

[Regular reflectance of undercoat layer]
The regular reflectance of the undercoat layer according to the present invention usually shows a specific value in the present invention. The regular reflectance of the undercoat layer according to the present invention indicates the regular reflectance of the undercoat layer on the conductive substrate relative to the conductive substrate. Since the regular reflectance of the undercoat layer varies depending on the thickness of the undercoat layer, it is defined here as the reflectance when the thickness of the undercoat layer is 2 μm.

When the refractive index of the metal oxide particles contained in the undercoat layer is 2.0 or more, the undercoat layer according to the present invention is converted to the case where the undercoat layer is 2 μm. The ratio of the regular reflection for light with a wavelength of 480 nm of the undercoat layer to the regular reflection for light with a wavelength of 480 nm is usually 50% or more.
On the other hand, when the refractive index of the metal oxide particles contained in the undercoat layer is less than 2.0, regular reflection with respect to light having a wavelength of 400 nm of the conductive substrate converted to the case where the undercoat layer is 2 μm. The ratio of regular reflection to light with a wavelength of 400 nm of the undercoat layer is usually 50% or more.

  Here, even when the undercoat layer contains a plurality of types of metal oxide particles having a refractive index of 2.0 or more, or when the undercoat layer contains a plurality of types of metal oxide particles having a refractive index of less than 2.0, Those having regular reflection similar to the above are preferred. In the case where the undercoat layer simultaneously contains metal oxide particles having a refractive index of 2.0 or more and metal oxide particles having a refractive index of less than 2.0, the metal oxide having a refractive index of 2.0 or more Similarly to the case of containing particles, the ratio of the regular reflection of the undercoat layer to the light of wavelength 480 nm to the regular reflection of the conductive substrate to the light of wavelength 480 nm, converted when the undercoat layer is 2 μm. However, it is preferable that it is said range (50% or more).

  As described above, the case where the film thickness of the undercoat layer is 2 μm has been described in detail. However, in the electrophotographic photoreceptor according to the present invention, the film thickness of the undercoat layer is not limited to 2 μm, and any film thickness can be obtained. It doesn't matter. When the thickness of the undercoat layer is other than 2 μm, it is equivalent to the electrophotographic photosensitive member using the undercoat layer forming coating solution (described later) used for forming the undercoat layer. An undercoat layer having a thickness of 2 μm can be applied and formed on the conductive substrate, and the regular reflectance of the undercoat layer can be measured. As another method, there is a method in which the regular reflectance of the undercoat layer of the electrophotographic photosensitive member is measured and converted when the film thickness is 2 μm.

Hereinafter, the conversion method will be described.
Assuming a thin layer of thickness dL perpendicular to the light when specific monochromatic light passes through the subbing layer, is specularly reflected on the conductive substrate, and is again detected through the subbing layer. .
The amount of decrease in light intensity −dI after passing through a thin layer having a thickness dL is considered to be proportional to the light intensity I before passing through the layer and the thickness dL of the layer. It can be written as follows (k is a constant):

-DI = kIdL (A)
The equation (A) is transformed as follows.
-DI / I = kdL (B)
When both sides of the formula (B) are integrated in the interval from I ₀ to I and from 0 to L, the following formula is obtained. Note that I ₀ represents the intensity of incident light.
log (I ₀ / I) = kL (C)

Equation (C) is the same as what is called Lambert's law in the solution system, and can also be applied to the measurement of reflectance in the present invention.
When formula (C) is transformed,
I = I ₀ exp (−kL) (D)
Thus, the behavior until the incident light reaches the surface of the conductive substrate is represented by the formula (D).

On the other hand, since the regular reflectance is a denominator of the reflected light of the incident light with respect to the conductive substrate, the reflectance R = I ₁ / I ₀ on the surface of the raw tube is considered. Here, I ₁ represents the intensity of the reflected light.
Then, the light that has reached the surface of the conductive substrate according to the formula (D) is regularly reflected after being multiplied by the reflectance R, and again passes through the optical path length L and exits to the surface of the undercoat layer. That is,
I = I ₀ exp (−kL) · R · exp (−kL) (E)
By substituting R = I ₁ / I ₀ and further transforming,
I / I ₁ = exp (−2 kL) (F)
Can be obtained. This is the value of the reflectivity for the undercoat layer relative to the reflectivity for the conductive substrate, and is defined as the regular reflectivity.

As described above, the optical path length of the undercoat layer of 2 μm is 4 μm in a reciprocating manner. The reflectivity T of the undercoat layer on any conductive substrate is determined by the thickness L of the undercoat layer (at this time) It is a function of the optical path length 2L, and is expressed as T (L). From equation (F)
T (L) = I / I ₁ = exp (−2 kL) (G)
Is established.
On the other hand, since the value we want to know is T (2), substituting L = 2 into equation (G),
T (2) = I / I ₁ = exp (−4k) (H)
Then, when k is deleted by simultaneous equations (G) and (H),
T (2) = T (L) ^{2 / L} (I)
It becomes.

  That is, when the thickness of the undercoat layer is L (μm), the reflectance T (2) when the undercoat layer is 2 μm is obtained by measuring the reflectivity T (L) of the undercoat layer. Can be estimated with considerable accuracy. The value of the film thickness L of the undercoat layer can be measured by an arbitrary film thickness measuring device such as a roughness meter.

[III. Method for forming undercoat layer]
There is no restriction | limiting in the formation method of the undercoat layer based on this invention. However, usually, an undercoat layer-forming coating solution containing metal oxide particles and a binder resin is applied to the surface of the conductive substrate and dried to obtain an undercoat layer.

[III-1. Undercoat layer forming coating solution]
The undercoat layer forming coating solution according to the present invention is used to form an undercoat layer, and contains metal oxide particles and a binder resin. In general, the coating solution for forming the undercoat layer according to the present invention contains a solvent. Furthermore, the coating liquid for undercoat layer formation concerning this invention may contain the other component in the range which does not impair the effect of this invention remarkably.

[III-1-1. Metal oxide particles]
The metal oxide particles are the same as those described as the metal oxide particles contained in the undercoat layer.
However, regarding the particle size distribution of the metal oxide particles in the undercoat layer forming coating solution according to the present invention, the following requirements are usually satisfied. That is, the volume average particle size and the cumulative 90% particle size measured by the dynamic light scattering method of the metal oxide particles in the coating solution for forming the undercoat layer according to the present invention are respectively for the above-described undercoat layer measurement. This is the same as the volume average particle size and cumulative 90% particle size measured by the dynamic light scattering method of the metal oxide particles in the dispersion.

Therefore, in the coating liquid for forming the undercoat layer according to the present invention, the volume average particle diameter of the metal oxide particles is usually 0.1 μm or less (refer to [volume average particle diameter of metal oxide particles]). .
In the undercoat layer forming coating liquid according to the present invention, the metal oxide particles are preferably present as primary particles. However, there are few such cases, and in most cases, they are aggregated and exist as aggregate secondary particles, or both are mixed. Therefore, how the particle size distribution should be in that state is very important.

  Therefore, in the undercoat layer forming coating solution according to the present invention, by setting the volume average particle diameter of the metal oxide particles in the undercoat layer forming coating solution within the above range (0.1 μm or less). Then, precipitation and viscosity change in the coating solution for forming the undercoat layer were reduced. Thereby, as a result, the film thickness and surface property after forming the undercoat layer can be made uniform. On the other hand, when the volume average particle size of the metal oxide particles is too large (over 0.1 μm), conversely, precipitation and viscosity change in the coating solution for forming the undercoat layer increase, resulting in Since the film thickness and surface properties after the formation of the pulling layer become non-uniform, the quality of the upper layer (such as a charge generation layer) may be adversely affected.

In the undercoat layer forming coating solution according to the present invention, the cumulative 90% particle diameter of the metal oxide particles is usually 0.3 μm or less (refer to [Regarding the cumulative 90% particle diameter of metal oxide particles]). ).
This is desirable if the metal oxide particles according to the present invention are present as spherical primary particles in the undercoat layer forming coating solution. However, such metal oxide particles are not practically obtained. Even if the metal oxide particles are agglomerated, the inventors of the present invention should have a 90% cumulative particle diameter that is sufficiently small, that is, if the cumulative 90% particle diameter is specifically 0.3 μm or less. For example, it has been found that the coating solution for forming the undercoat layer has little gelation and viscosity change and can be stored for a long period of time, and as a result, the film thickness and surface properties after forming the undercoat layer are uniform. On the other hand, if the metal oxide particles in the coating solution for forming the undercoat layer are too large, gelation and viscosity change in the solution are large, resulting in non-uniform film thickness and surface properties after forming the undercoat layer. Therefore, the quality of the upper layer (such as a charge generation layer) may be adversely affected.

  The method for measuring the volume average particle size and the cumulative 90% particle size of the metal oxide particles in the undercoat layer forming coating solution is to measure the metal oxide particles in the undercoat layer measurement dispersion. Instead, the coating liquid for forming the undercoat layer is directly measured. The volume average particle diameter and cumulative 90% particle diameter of the metal oxide particles in the above-described undercoat layer measurement dispersion liquid are as follows. It is different from the measurement method. Except for the following points, the measurement method of the volume average particle diameter and cumulative 90% particle diameter of the metal oxide particles in the undercoat layer forming coating solution is the same as the metal oxidation in the undercoat layer measurement dispersion liquid. This is the same as the method for measuring the volume average particle size and cumulative 90% particle size of the product particles.

  That is, when measuring the volume average particle size and cumulative 90% particle size of the metal oxide particles in the coating solution for forming the undercoat layer, the type of dispersion medium is the solvent used in the coating solution for forming the undercoat layer. The dispersion medium refractive index is the refractive index of the solvent used in the coating solution for forming the undercoat layer. In addition, when the coating solution for forming the undercoat layer is too thick and the concentration is outside the measurable range of the measuring device, the coating solution for forming the undercoat layer is mixed with a mixed solvent of methanol and 1-propanol ( (Weight ratio: methanol / 1-propanol = 7/3; refractive index = 1.35) so that the concentration of the coating solution for forming the undercoat layer falls within a measurable range. For example, in the case of the above UPA, the coating solution for forming the undercoat layer is mixed with a mixed solvent of methanol and 1-propanol so that the sample concentration index (SIGNAL LEVEL) suitable for measurement is 0.6 to 0.8. Dilute. Since the volume particle diameter of the metal oxide particles in the coating solution for forming the undercoat layer is considered not to change even when diluted in this way, the volume average particle diameter measured as a result of the dilution described above Further, the cumulative 90% particle size is treated as the volume average particle size and cumulative 90% particle size of the metal oxide particles in the coating solution for forming the undercoat layer.

In addition, the absorbance of the coating solution for forming the undercoat layer according to the present invention can be measured with a generally known spectrophotometer (absorption spectrophotometer). Conditions such as cell size and sample concentration when measuring absorbance vary depending on physical properties such as the particle diameter and refractive index of the metal oxide particles to be used. Therefore, in general, in the wavelength region to be measured (in the present invention, (400 nm to 1000 nm), the sample concentration is appropriately adjusted so as not to exceed the measurement limit of the detector. In the present invention, the sample concentration is adjusted so that the amount of the metal oxide particles in the coating solution for forming the undercoat layer is 0.0075 wt% to 0.012 wt%. The solvent used to prepare the sample concentration is usually the solvent used as the solvent for the coating solution for forming the undercoat layer, but is compatible with the solvent for the coating solution for forming the undercoat layer and the binder resin. Any mixture can be used as long as it does not cause turbidity when mixed and does not have large light absorption in the wavelength region of 400 nm to 1000 nm. Specific examples include alcohols such as methanol, ethanol, 1-propanol and 2-propanol; hydrocarbons such as toluene and xylene; ethers such as tetrahydrofuran; ketones such as methyl ethyl ketone and methyl isobutyl ketone. .
The cell size (optical path length) for measurement is 10 mm. Any cell may be used as long as it is substantially transparent in the range of 400 nm to 1000 nm, but it is preferable to use a quartz cell, and in particular, a sample cell and a standard cell. It is preferable to use a matched cell that has a difference in transmittance characteristics within a specific range.

[III-1-2. Binder resin]
The binder resin contained in the undercoat layer forming coating solution is the same as that described as the binder resin contained in the undercoat layer.
However, the content of the binder resin in the coating solution for forming the undercoat layer is arbitrary as long as the effect of the present invention is not significantly impaired, but is usually 0.5% by weight or more, preferably 1% by weight or more, and usually 20%. It is used in the range of not more than wt%, preferably not more than 10 wt%.

[III-1-3. solvent]
As the solvent (undercoat layer solvent) used in the coating solution for forming the undercoat layer according to the present invention, any solvent can be used as long as it can dissolve the binder resin according to the present invention. As this solvent, an organic solvent is usually used. Examples of the solvent include alcohols having 5 or less carbon atoms such as methanol, ethanol, isopropyl alcohol or normal propyl alcohol; chloroform, 1,2-dichloroethane, dichloromethane, trichrene, carbon tetrachloride, 1,2-dichloropropane, etc. Halogenated hydrocarbons; nitrogen-containing organic solvents such as dimethylformamide; aromatic hydrocarbons such as toluene and xylene.

  Moreover, the said solvent may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio. Furthermore, even if the solvent alone does not dissolve the binder resin according to the present invention, it can be used as long as the binder resin can be dissolved by using a mixed solvent with other solvents (for example, the organic solvents exemplified above). can do. In general, coating unevenness can be reduced by using a mixed solvent.

  In the coating solution for forming the undercoat layer according to the present invention, the amount ratio of the solvent and the solid content such as metal oxide particles and binder resin varies depending on the coating method of the coating solution for forming the undercoat layer, and the coating method to be applied In order to form a uniform coating film, it may be appropriately changed and used. Specifically, the concentration of the solid content in the coating solution for forming the undercoat layer is usually 1% by weight or more, preferably 2% by weight or more, and usually 30% by weight or less, preferably 25% by weight or less. It is preferable from the viewpoints of stability and coatability of the coating solution for forming the undercoat layer.

[III-1-4. Other ingredients]
The other components contained in the undercoat layer forming coating solution are the same as those described as the other components contained in the undercoat layer.

[III-1-5. Advantages of coating solution for undercoat layer formation]
The coating solution for forming the undercoat layer according to the present invention has high storage stability. There are various storage stability indexes. For example, the coating solution for forming the undercoat layer according to the present invention has a viscosity change rate at the time of preparation and after storage at room temperature for 120 days (that is, viscosity after storage for 120 days). The value obtained by dividing the difference between the viscosity at the time of production and the viscosity at the time of production) is usually 20% or less, preferably 15% or less, more preferably 10% or less. The viscosity can be measured by a method according to JIS Z 8803 using an E-type viscometer (manufactured by Tokimec, product name ED).
Further, by using the undercoat layer forming coating solution according to the present invention, it is possible to produce an electrophotographic photoreceptor with high quality and high efficiency.

[III-2. Manufacturing method of coating liquid for forming undercoat layer]
There is no restriction | limiting in the manufacturing method of the coating liquid for undercoat layer formation concerning this invention. However, the coating solution for forming the undercoat layer according to the present invention contains the metal oxide particles as described above, and the metal oxide particles are dispersed in the coating solution for forming the undercoat layer. Therefore, the manufacturing method of the undercoat layer forming coating liquid according to the present invention usually has a dispersion step of dispersing the metal oxide particles.

  In order to disperse the metal oxide particles, for example, a known mechanical grinding device (dispersing device) such as a ball mill, a sand grind mill, a planetary mill, or a roll mill is used. What is necessary is just to carry out wet dispersion in a solvent. By this dispersion step, it is considered that the metal oxide particles according to the present invention are dispersed and have the predetermined particle size distribution described above. Moreover, the dispersion solvent may use the solvent used for the coating liquid for undercoat layer formation, and may use the other solvent. However, when a solvent other than the solvent used for the coating solution for forming the undercoat layer is used as the dispersion solvent, the metal oxide particles and the solvent used for the coating solution for forming the undercoat layer are mixed or solvent-exchanged after dispersion. However, in this case, it is preferable to carry out the above mixing or solvent exchange while preventing the metal oxide particles from aggregating to have a predetermined particle size distribution.

Among the wet dispersion methods, those using a dispersion medium are particularly preferable.
Any known dispersion device may be used as a dispersion device for dispersion using a dispersion medium. Examples of a dispersing device that disperses using a dispersion medium include a pebble mill, a ball mill, a sand mill, a screen mill, a gap mill, a vibration mill, a paint shaker, and an attritor. Among these, those that can circulate and disperse the metal oxide particles are preferable. In addition, wet stirring ball mills such as a sand mill, a screen mill, and a gap mill are particularly preferable from the viewpoints of dispersion efficiency, fineness of reached particle diameter, ease of continuous operation, and the like. These mills may be either vertical or horizontal. The disc shape of the mill can be any plate type, vertical pin type, horizontal pin type or the like. Preferably, a liquid circulation type sand mill is used.
In addition, these dispersion apparatuses may be implemented by only 1 type, and may be implemented in arbitrary combinations of 2 or more types.

  Further, when dispersing using a dispersion medium, by using a dispersion medium having a predetermined average particle diameter, the volume average particle diameter of the metal oxide particles in the coating liquid for forming the undercoat layer and the above accumulation The 90% particle size can be within the above-mentioned range.

  That is, in the method for producing a coating liquid for forming an undercoat layer according to the present invention, when metal oxide particles are dispersed in a wet stirring ball mill, the average particle size is usually used as a dispersion medium of the wet stirring ball mill. A dispersion medium of 5 μm or more, preferably 10 μm or more, and usually 200 μm or less, preferably 100 μm or less is used. A dispersion medium having a small particle size tends to give a uniform dispersion in a short time. However, if the particle size is excessively small, there is a possibility that the mass of the dispersion medium becomes too small to perform efficient dispersion.

  In addition, the use of a dispersion medium having an average particle size as described above allows the volume average particle size and cumulative 90% particle size of the metal oxide particles in the coating solution for forming the undercoat layer to be obtained by the manufacturing method described above. It is considered that this is one of the factors that can fall within the desired range. Therefore, the coating solution for forming the undercoat layer produced using the metal oxide particles dispersed using the dispersion medium having the above average particle size in the wet stirring ball mill is the undercoat layer forming coating solution according to the present invention. It satisfies the liquid requirements well.

  Since the dispersion medium usually has a shape close to a true sphere, for example, the average particle diameter can be obtained by measuring by sieving using a sieve described in JIS Z 8801: 2000 or by image analysis, The density can be measured by the Archimedes method. Specifically, for example, the average particle diameter and sphericity of the dispersion medium can be measured by an image analyzer represented by LUZEX50 manufactured by Nireco Corporation.

Although there is no restriction | limiting in the density of a dispersion medium, A thing of 5.5 g / cm < ³ > or more is used normally, Preferably it is 5.9 g / cm < ³ > or more, More preferably, a thing of 6.0 g / cm < ³ > or more is used. Generally, dispersion using a higher density dispersion medium tends to give a uniform dispersion in a shorter time. The sphericity of the dispersion medium is preferably 1.08 or less, more preferably a dispersion medium having a sphericity of 1.07 or less.

As the material of the dispersion medium, any known material can be used as long as it is insoluble in the dispersion solvent contained in the slurry and has a specific gravity greater than that of the slurry and does not react with the slurry or alter the slurry. Any distributed media can be used. Examples include steel balls such as chrome balls (ball balls for ball bearings) and carbon balls (carbon steel balls); stainless steel balls; ceramic balls such as silicon nitride balls, silicon carbide, zirconia, and alumina; titanium nitride, carbonitride Examples thereof include a sphere coated with a film of titanium or the like. Among these, ceramic spheres are preferable, and zirconia fired balls are particularly preferable. More specifically, it is particularly preferable to use zirconia fired beads described in Japanese Patent No. 3400836.
Note that only one type of dispersion medium may be used, or two or more types may be used in any combination and ratio.

Further, among the wet stirring ball mills, in particular, a cylindrical stator, a slurry supply port provided at one end of the stator, a slurry discharge port provided at the other end of the stator, and a dispersion medium filled in the stator And a rotor that stirs and mixes the slurry supplied from the supply port and a discharge port, and is rotatably provided to separate the dispersion medium and the slurry by the action of centrifugal force, and discharge the slurry from the discharge port. It is preferable to use what is provided with the separator for doing.
Here, the slurry contains at least metal oxide particles and a dispersion solvent.

Hereinafter, the configuration of this wet stirring ball mill will be described in detail.
The stator is a cylindrical (usually cylindrical) container having a hollow portion therein, and a slurry supply port is formed at one end and a slurry discharge port is formed at the other end. Furthermore, the inside hollow portion is filled with a dispersion medium, and the metal oxide particles in the slurry are dispersed by the dispersion medium. The slurry is supplied from the supply port into the stator, and the slurry in the stator is discharged from the discharge port to the outside of the stator.

  The rotor is provided inside the stator, and stirs and mixes the dispersion medium and the slurry. Note that the rotor type includes, for example, a pin, a disk, an annular type, and any type of rotor may be used.

  Furthermore, the separator separates the dispersion medium and the slurry. This separator is provided so as to be connected to the discharge port of the stator. And it is comprised so that the slurry and dispersion medium in a stator may be isolate | separated and a slurry may be sent out of the stator from the discharge port of a stator.

In addition, the separator used here is rotatably provided, preferably an impeller type, so that the dispersion medium and the slurry are separated by the action of centrifugal force generated by the rotation of the separator. It has become.
Note that the separator may be rotated integrally with the rotor, or may be rotated independently of the rotor.

  Moreover, it is preferable that the wet stirring ball mill is provided with a shaft that serves as a rotating shaft of the separator. Furthermore, it is preferable that a hollow discharge path communicating with the discharge port is formed at the shaft center of the shaft. That is, the wet stirring ball mill includes at least a cylindrical stator, a slurry supply port provided at one end of the stator, a slurry discharge port provided at the other end of the stator, a dispersion medium filled in the stator, and A rotor that stirs and mixes the slurry supplied from the supply port, and an impeller that is connected to the discharge port and is rotatably provided to separate the dispersion medium and the slurry by the action of centrifugal force and discharge the slurry from the discharge port. Preferably, the separator is configured to include a type separator and a shaft that serves as a rotation axis of the separator, and a hollow discharge path that communicates with the discharge port is formed in the shaft center.

  The discharge passage formed in the shaft communicates the rotation center of the separator and the discharge port of the stator. For this reason, the slurry separated from the dispersion medium by the separator is sent to the discharge port through the discharge path, and discharged from the discharge port to the outside of the stator. At this time, although the discharge passage passes through the shaft center, the centrifugal force does not act on the shaft, so that the slurry is discharged without kinetic energy. For this reason, kinetic energy is not wasted and useless power is not consumed.

  Such a wet stirring ball mill may be horizontally oriented, but is preferably oriented vertically in order to increase the filling rate of the dispersion medium. At this time, the discharge port is preferably provided at the upper end of the mill. Further, in this case, it is desirable to provide a separator above the level of the dispersion medium filled.

  When the discharge port is provided at the upper end of the mill, the supply port is provided at the bottom of the mill. In this case, as a more preferable aspect, the supply port is configured by a valve seat, and a V-shaped, trapezoidal, or cone-shaped valve body that is fitted to the valve seat so as to be movable up and down and can be in line contact with the edge of the valve seat. To do. This makes it possible to form an annular slit between the edge of the valve seat and the valve body so that the dispersion medium cannot pass through. Therefore, the slurry is supplied at the supply port, but the dispersion medium can be prevented from falling. Further, it is possible to widen the slit to raise the valve body to discharge the dispersion medium, or to lower the valve body to close the slit and seal the mill. Further, since the slit is formed by the edge of the valve body and the valve seat, coarse particles (metal oxide particles) in the slurry are difficult to bite, and even if they are bitten, they are easily pulled up and down and are not easily clogged.

  Further, if the valve body is caused to vibrate up and down by the vibration means, the coarse particles caught in the slit can be pulled out from the slit, and the biting itself is difficult to occur. In addition, the shearing force is applied to the slurry by the vibration of the valve body, the viscosity is lowered, and the amount of slurry passing through the slit (that is, the supply amount) can be increased. There is no limitation on the vibration means for vibrating the valve body. For example, in addition to mechanical means such as a vibrator, means for changing the pressure of compressed air acting on a piston integrated with the valve body, for example, a reciprocating compressor In addition, an electromagnetic switching valve for switching intake / exhaust of compressed air can be used.

  In such a wet stirring ball mill, it is desirable that a screen for separating the dispersion medium and a slurry outlet are provided at the bottom so that the slurry remaining in the wet stirring ball mill can be taken out after the dispersion is completed.

  In addition, the wet stirring ball mill is installed vertically, and the shaft is pivotally supported on the upper end of the stator, and an O-ring and a mechanical seal having a mating ring are provided on the bearing portion for supporting the shaft at the upper end of the stator. When an O-ring is fitted into the bearing and an O-ring is fitted to the annular groove, a tapered shape that expands downward is formed on the lower side of the annular groove. It is preferable to form a notch. That is, a wet stirring ball mill is supported by a cylindrical vertical stator, a slurry supply port provided at the bottom of the stator, a slurry discharge port provided at the upper end of the stator, and an upper end of the stator. A shaft that is rotationally driven by the driving means, a pin, a disk or an annulus type rotor that is fixed to the shaft and that stirs and mixes the dispersion medium filled in the stator and the slurry supplied from the supply port, and near the discharge port The separator that separates the dispersion media from the slurry and the mechanical seal that is provided on the bearing that supports the shaft at the upper end of the stator, and the O-ring that contacts the mating ring of the mechanical seal are fitted. Forming a tapered incision that expands downward in the lower part of the annular groove Preferred.

According to the above-described wet stirring ball mill, the mechanical seal is provided at the shaft center where the dispersion medium or slurry has little kinetic energy and at the upper end of the stator above the liquid surface level. And dispersion medium and slurry can be greatly reduced between the lower portion of the O-ring fitting groove.
In addition, the lower portion of the annular groove into which the O-ring is fitted is expanded downward by cutting, and the clearance is widened. Therefore, the slurry and the dispersion medium are jammed and solidified due to clogging or solidification. This prevents the mating ring from following the seal ring smoothly and maintains the function of the mechanical seal. In addition, since the lower part of the fitting groove into which the O-ring is fitted has a V-shaped cross section and the whole is not thin, the strength is not impaired, and the holding function of the O-ring is also impaired. Absent.

  In particular, the separator has two disks each provided with a fitting groove for a blade on the opposite inner surface, a blade that is fitted in the fitting groove and is interposed between the disks, and a blade. It is preferable to include a supporting means for sandwiching the disk from both sides. That is, as the wet stirring ball mill, a cylindrical stator, a slurry supply port provided at one end of the stator, a slurry discharge port provided at the other end of the stator, and the stator filled A dispersion medium, a rotor for stirring and mixing the slurry supplied from the supply port, and connected to the discharge port and rotatably provided in the stator, and the dispersion medium and the slurry are rotated by the action of centrifugal force. And a separator for discharging the slurry from the discharge port, and the separator is provided with two disks provided with a fitting groove of a blade on the opposing inner surface, and the fitting The blade fitted in a groove and interposed between the disks, and support means for clamping the disk with the blades interposed from both sides; It is preferable to equip. In this case, in a preferred embodiment, the support means is composed of a shaft step that forms a stepped shaft and a cylindrical presser unit that fits into the shaft and presses the disk, and the shaft step and the presser unit are used to hold the blade. The intervening disc is sandwiched and supported from both sides. By such a wet stirring ball mill, the metal oxide particles in the undercoat layer can easily be within the range of the volume average particle size and the cumulative 90% particle size. Here, the separator preferably has an impeller type configuration.

Hereinafter, in order to more specifically describe the configuration of the above-described vertical wet stirring ball mill, an embodiment of the wet stirring ball mill will be described. However, the stirrer used for producing the undercoat layer coating solution of the present invention is not limited to those exemplified here.
FIG. 7 is a longitudinal sectional view schematically showing the configuration of the wet stirring ball mill of this embodiment. In FIG. 7, slurry (not shown) is supplied to a vertical wet stirring ball mill, pulverized by being stirred together with the dispersion medium (not shown) in the mill, and then the dispersion medium is separated by the separator 14 and the shaft. The material is discharged through a discharge passage 19 formed at the center of 15 shafts, followed by a return route (not shown), and circulated and crushed.

  As shown in detail in FIG. 7, the vertical wet stirring ball mill includes a stator 17 having a longitudinally cylindrical shape and a jacket 16 through which cooling water for cooling the mill is passed, and an axis of the stator 17. And a shaft 15 provided with a mechanical seal as shown in FIG. 8 (described later) in the bearing portion and having a shaft center on the upper side as a hollow discharge passage 19. A pin or disk-shaped rotor 21 projecting in the radial direction at the lower end of the shaft 15, a pulley 24 fixed to the upper part of the shaft 15 and transmitting a driving force, and an open end at the upper end of the shaft 15. A rotary joint 25, a separator 14 for separating media fixed to the shaft 15 near the top in the stator 17, and a shaft 15 at the bottom of the stator 17. It is mounted on a grid-like screen support 27 installed at a slurry supply port 26 provided opposite to the shaft end and a slurry take-out port 29 provided at an eccentric position at the bottom of the stator 17 to separate the dispersion media. And a screen 28.

  The separator 14 is composed of a pair of disks 31 fixed to the shaft 15 at a predetermined interval and a blade 32 connecting the disks 31 to form an impeller. Centrifugal force is applied to the dispersion medium and the slurry that have entered, and the dispersion medium is blown outward in the radial direction due to the difference in specific gravity, while the slurry is discharged through the discharge passage 19 at the shaft center of the shaft 15. .

  The slurry supply port 26 is composed of an inverted trapezoidal valve body 35 that fits up and down on a valve seat formed at the bottom of the stator 17, and a bottomed cylindrical body 36 that projects downward from the bottom of the stator 17. When the valve body 35 is pushed up by the supply of slurry, an annular slit (not shown) is formed between the valve seat 35 and the slurry, so that the slurry is supplied into the stator 17.

The valve body 35 at the time of supplying the raw material rises against the pressure in the mill due to the supply pressure of the slurry fed into the cylindrical body 36, and forms a slit between the valve seat 35 and the valve seat.
In order to eliminate clogging at the slit, the valve body 35 can be lifted up and down to the upper limit position in a short cycle to eliminate biting. The valve body 35 may be vibrated at all times or when the slurry contains a large amount of coarse particles. When the slurry supply pressure rises due to clogging, the valve body 35 is interlocked with this. May be performed.

  As shown in detail in FIG. 8, the mechanical seal is formed by pressing a mating ring 101 on the stator side to a seal ring 100 fixed to the shaft 15 by the action of a spring 102, thereby sealing the stator 17 and the mating ring 101. Is performed by an O-ring 104 that fits in the stator-side fitting groove 103. In FIG. 8, the lower portion of the O-ring fitting groove 103 has a tapered shape that expands downward. A notch (not shown) is inserted, the length a of the minimum clearance portion between the lower portion of the fitting groove 103 and the mating ring 101 is narrow, and media and slurry enter and solidify. The movement of 101 is not hindered so that the seal with the seal ring 100 is not impaired.

  In the above embodiment, the rotor 21 and the separator 14 are fixed to the same shaft 15, but in another embodiment, the rotor 21 and the separator 14 are fixed to separate shafts arranged on the same axis and are driven to rotate separately. In the above-described embodiment in which the rotor and the separator are attached to the same shaft, the structure is simplified because only one drive device is required. On the other hand, the rotor and the shaft are attached to separate shafts, and the drive is separated. In the latter embodiment, which is driven to rotate by the apparatus, the rotor and the separator can be driven at optimum rotational speeds, respectively.

In the ball mill shown in FIG. 9, the shaft 105 is a stepped shaft, the separator 106 is inserted from the lower end of the shaft, the spacer 107 and the disk or pin-shaped rotor 108 are alternately inserted, and the stopper 109 is inserted at the lower end of the shaft. The separator 106 is fastened by a screw 110, and the separator 106, the spacer 107 and the rotor 108 are sandwiched and fixed by a step 105a of the shaft 105 and a stopper 109. The separator 106 is a surface facing the inside as shown in FIG. A pair of discs 115 each having a blade fitting groove 114 formed thereon, a blade 116 interposed between the two discs and fitted in the blade fitting groove 114, and the two discs 115 are maintained at a constant interval, and the discharge path 111 is formed by an annular spacer 113 having a hole 112 communicating with 111. Constitute the La.
In addition, specifically as a wet stirring ball mill which has a structure which was illustrated by this embodiment, the ultra apex mill made from a Kotobuki industry is mentioned, for example.

  Since the wet stirring ball mill of the present embodiment is configured as described above, the slurry is dispersed by the following procedure. That is, a dispersion medium (not shown) is filled in the stator 17 of the wet stirring ball mill of this embodiment, and the rotor 21 and the separator 14 are driven to rotate by external power, while a certain amount of slurry is supplied. 26. Thus, slurry is supplied into the stator 7 through a slit (not shown) formed between the edge of the valve seat and the valve body 35.

  The slurry in the stator 7 and the dispersion medium are agitated and mixed by the rotation of the rotor 21 and the slurry is pulverized. Further, the dispersion medium and the slurry that have entered the separator 14 are separated by the difference in specific gravity due to the rotation of the separator 14, and the dispersion medium having a high specific gravity is blown outward in the radial direction, whereas the slurry having a low specific gravity is transferred to the shaft 15. Is discharged through a discharge passage 19 formed at the axis of the material and returned to the raw material tank. When the pulverization has progressed to some extent, the particle size of the slurry is appropriately measured. When the desired particle size is reached, the raw material pump is stopped, the mill operation is stopped, and the pulverization is terminated.

  In addition, when the metal oxide particles are dispersed using a wet stirring ball mill, there is no limitation on the filling rate of the dispersion medium filled in the wet stirring ball mill, and the metal oxide particles are dispersed until a desired particle size distribution is obtained. If it can be performed, it is arbitrary. However, when the metal oxide particles are dispersed using the vertical wet stirring ball mill as described above, the filling rate of the dispersion medium filled in the wet stirring ball mill is usually 50% or more, preferably 70% or more. , More preferably 80% or more, and usually 100% or less, preferably 95% or less, more preferably 90% or less.

  In the wet stirring ball mill applied to disperse the metal oxide particles, the separator may be a screen or a slit mechanism, but as described above, an impeller type is desirable, and a vertical type is preferable. It is desirable that the wet stirring ball mill be oriented vertically and the separator be provided at the top of the mill. Particularly when the filling rate of the dispersion medium is set within the above range, the grinding is most efficiently performed, and the separator is more than the media filling level. It becomes possible to position it above, and there is an effect that it is possible to prevent the dispersion medium from being discharged on the separator.

  The operating conditions of the wet stirring ball mill applied to disperse the metal oxide particles include the volume average particle diameter and cumulative 90% particle diameter of the metal oxide particles in the coating solution for forming the undercoat layer, subbing Stability of the layer forming coating solution, surface shape of the undercoat layer formed by applying and forming the undercoat layer forming coating solution, and electron having an undercoat layer formed by applying and forming the undercoat layer forming coating solution Affects the characteristics of photographic photoreceptors. In particular, the slurry supply speed and the rotational speed of the rotor are considered to have a great influence.

  The slurry supply speed is related to the time during which the slurry stays in the wet stirring ball mill, and is therefore affected by the volume of the mill and its shape. In the case of a commonly used stator, the volume of the wet stirring ball mill is 1 liter (hereinafter referred to as L Is usually 20 kg / hour or more, preferably 30 kg / hour or more, and usually 80 kg / hour or less, preferably 70 kg / hour or less.

  The rotational speed of the rotor is affected by parameters such as the rotor shape and the gap with the stator. In the case of a commonly used stator and rotor, the peripheral speed of the rotor tip is usually 5 m / second or more, preferably The range is 8 m / second or more, more preferably 10 m / second or more, and usually 20 m / second or less, preferably 15 m / second or less, more preferably 12 m / second or less.

  Furthermore, there is no limit on the amount of distributed media used. However, the dispersion medium is usually used in a volume ratio of 1 to 5 times that of the slurry. In addition to the dispersion medium, a dispersion aid that can be easily removed after dispersion can be used in combination. Examples of the dispersion aid include sodium chloride and sodium nitrate.

The metal oxide particles are preferably dispersed in the presence of a dispersion solvent in a wet manner. Moreover, as long as the metal oxide particles can be appropriately dispersed, components other than the dispersion solvent may coexist. Examples of such components that may coexist include binder resins and various additives.
The dispersion solvent is not particularly limited, but if the solvent used in the coating solution for forming the undercoat layer is used, it is preferable that a step such as solvent exchange is not required after dispersion. Any one of these dispersion solvents may be used alone, or two or more of these dispersion solvents may be used in any combination and ratio, and may be used as a mixed solvent.

From the viewpoint of productivity, the amount of the dispersion solvent used is usually 0.1 parts by weight or more, preferably 1 part by weight or more, and usually 500 parts by weight or less with respect to 1 part by weight of the metal oxide to be dispersed. The range is preferably 100 parts by weight or less.
The temperature at the time of mechanical dispersion can be from the freezing point of the solvent (or mixed solvent) to the boiling point or less, but from the viewpoint of safety during production, it is usually 10 ° C. or more and 200 ° C. or less. It is performed in the range.

After the dispersion treatment using the dispersion medium, it is preferable to separate and remove the dispersion medium from the slurry and to perform ultrasonic treatment. The ultrasonic treatment applies ultrasonic vibration to the metal oxide particles.
There are no particular restrictions on the conditions for ultrasonic treatment such as the vibration frequency, but ultrasonic vibration is applied by an oscillator having a frequency of usually 10 kHz or more, preferably 15 kHz or more, and usually 40 kHz or less, preferably 35 kHz or less.
Moreover, although there is no restriction | limiting in particular in the output of an ultrasonic oscillator, Usually 100W-5kW thing is used.

  Furthermore, it is usually better to disperse a small amount of slurry with ultrasonic waves from a small output ultrasonic oscillator than to process a large amount of slurry with ultrasonic waves from a high output ultrasonic oscillator. Therefore, the amount of slurry to be treated at one time is usually 1 L or more, preferably 5 L or more, more preferably 10 L or more, and usually 50 L or less, preferably 30 L or less, more preferably 20 L or less. In this case, the output of the ultrasonic oscillator is preferably 200 W or more, more preferably 300 W or more, still more preferably 500 W or more, and preferably 3 kW or less, more preferably 2 kW or less, and even more preferably 1.5 kW or less. It is.

  There is no particular limitation on the method of applying ultrasonic vibration to the metal oxide particles. For example, the method of directly immersing the ultrasonic oscillator in the container containing the slurry, or contacting the ultrasonic oscillator on the outer wall of the container containing the slurry. And a method of immersing a container containing a slurry in a liquid that has been vibrated by an ultrasonic oscillator. Among these methods, a method of immersing a container containing slurry in a liquid that has been vibrated by an ultrasonic oscillator is preferably used.

  In the above case, the liquid to be vibrated by the ultrasonic oscillator is not limited, but examples thereof include water; alcohols such as methanol; aromatic hydrocarbons such as toluene; and fats and oils such as silicone oil. Among them, it is preferable to use water in consideration of safety in production, cost, cleanability and the like.

  In the method of immersing a container containing slurry in a liquid that has been vibrated by an ultrasonic oscillator, it is preferable to keep the temperature of the liquid constant because the efficiency of ultrasonic treatment changes depending on the temperature of the liquid. . The temperature of the liquid to which vibration is applied may increase due to the applied ultrasonic vibration. The temperature of the liquid is usually 5 ° C. or higher, preferably 10 ° C. or higher, more preferably 15 ° C. or higher, and usually 60 ° C. or lower, preferably 50 ° C. or lower, more preferably 40 ° C. or lower. It is preferable to do.

  There is no limitation on the container in which the slurry is placed when ultrasonic treatment is performed. For example, any container can be used as long as it is a container that is normally used to contain a coating solution for forming an undercoat layer used for forming a photosensitive layer for an electrophotographic photoreceptor. Specific examples include a resin container such as polyethylene and polypropylene, a glass container, and a metal can. Among these, metal cans are preferable, and in particular, 18 liter metal cans as defined in JIS Z 1602 are preferably used. This is because it is hardly affected by organic solvents and is strong against impact.

  Moreover, the slurry after dispersion and the slurry after ultrasonic treatment are used after being filtered as necessary in order to remove coarse particles. As filtration media in this case, any filtration media such as cellulose fiber, resin fiber, and glass fiber, which are usually used for filtration, may be used. As a form of the filtration media, a so-called wind filter in which various fibers are wound around a core material is preferable because of a large filtration area and high efficiency. As the core material, any conventionally known core material can be used. Examples of the core material include stainless steel core materials and polypropylene-made resin core materials that do not dissolve in the slurry and the solvent contained in the slurry.

  The slurry thus obtained further contains a solvent, a binder resin (binder), other components (auxiliaries, etc.) as necessary to form a coating liquid for forming an undercoat layer. In addition, the metal oxide particles are used as needed for the solvent and binder resin for the coating solution for forming the undercoat layer, before, during or after the dispersion or sonication step. What is necessary is just to mix with the other component made. Therefore, the mixing of the metal oxide particles with the solvent, binder resin, other components, etc. is not necessarily performed after the dispersion or ultrasonic treatment.

  As described above, according to the method for producing an undercoat layer forming coating solution according to the present invention, the undercoat layer forming coating solution according to the present invention can be efficiently produced, and the undercoat layer has higher storage stability. A forming coating solution can be obtained. Therefore, a higher quality electrophotographic photosensitive member can be obtained efficiently.

[III-3. Formation of undercoat layer]
The undercoat layer according to the present invention can be formed by applying the coating liquid for forming the undercoat layer according to the present invention onto a conductive substrate and drying it. There is no limitation on the method for applying the coating solution for forming the undercoat layer according to the present invention, but examples include dip coating, spray coating, nozzle coating, spiral coating, ring coating, bar coating coating, roll coating coating, blade coating, and the like. Can be mentioned. In addition, these coating methods may be implemented only by 1 type, and may be implemented in arbitrary combinations of 2 or more types.

  Examples of the spray coating method include air spray, airless spray, electrostatic air spray, electrostatic airless spray, rotary atomizing electrostatic spray, hot spray, and hot airless spray. Further, considering the atomization degree for obtaining a uniform film thickness, the adhesion efficiency, etc., in the rotary atomizing electrostatic spray, the conveying method disclosed in the republished publication No. 1-805198, that is, cylindrical It is preferable that the workpiece is continuously conveyed without being spaced apart in the axial direction while rotating the workpiece. Thereby, an electrophotographic photoreceptor excellent in uniformity of the thickness of the undercoat layer can be obtained with a comprehensively high adhesion efficiency.

Examples of the spiral coating method include a method using a liquid injection coating machine or a curtain coating machine disclosed in Japanese Patent Laid-Open No. 52-119651, and paint from a minute opening disclosed in Japanese Patent Laid-Open No. 1-2231966. There are a method of continuously flying in a streak shape, a method using a multi-nozzle body disclosed in JP-A-3-193161, and the like.
In the case of the dip coating method, the total solid concentration of the coating solution for forming the undercoat layer is usually 1% by weight or more, preferably 10% by weight or more, and usually 50% by weight or less, preferably 35% by weight or less. The viscosity is preferably 0.1 cps or more, and preferably 100 cps or less. Note that 1 cps = 1 × 10 ⁻³ Pa · s.

  After coating, the coating film is dried, but it is preferable to adjust the drying temperature and time so that necessary and sufficient drying is performed. The drying temperature is usually 100 ° C. or higher, preferably 110 ° C. or higher, more preferably 115 ° C. or higher, and usually 250 ° C. or lower, preferably 170 ° C. or lower, more preferably 140 ° C. or lower. There is no restriction | limiting in the drying method, For example, a hot air dryer, a steam dryer, an infrared dryer, a far-infrared dryer, etc. can be used.

[IV. Photosensitive layer]
As the structure of the photosensitive layer, any structure applicable to a known electrophotographic photoreceptor can be adopted. As a specific example, a so-called single-layer type photoreceptor having a single-layer photosensitive layer (that is, a single-layer type photosensitive layer) in which a photoconductive material is dissolved or dispersed in a binder resin; containing a charge generating substance. Examples include a so-called multilayer photoreceptor having a photosensitive layer (that is, a multilayer photosensitive layer) composed of a plurality of layers formed by laminating a charge generation layer and a charge transport layer containing a charge transport material. In general, it is known that the photoconductive material exhibits the same performance as a function regardless of whether it is a single layer type or a laminated type.

  The photosensitive layer of the electrophotographic photosensitive member of the present invention may be in any known form. However, in consideration of the mechanical properties, electrical characteristics, manufacturing stability, etc. of the photosensitive member, A photoreceptor is preferred. In particular, a sequential lamination type photoreceptor in which an undercoat layer, a charge generation layer, and a charge transport layer are laminated in this order on a conductive substrate is more preferable.

[IV-1. Charge generation material]
As the charge generating material used in the electrophotographic photoreceptor in the present invention, any material that has been proposed for use in the present application can be used. Examples of such substances are azo pigments, phthalocyanine pigments, anthanthrone pigments, quinacridone pigments, cyanine pigments, pyrylium pigments, thiapyrylium pigments, indigo pigments, polycyclic quinone pigments, squaric acids. And pigments. Particularly preferred are phthalocyanine pigments or azo pigments. The phthalocyanine pigment provides a photosensitive material with high sensitivity to a laser beam having a relatively long wavelength, and the azo pigment has a sufficient sensitivity to white light and a laser beam having a relatively short wavelength. , Each is excellent.

  In the present invention, when a phthalocyanine compound is used as the charge generating substance, a high effect is shown and preferable. Specific examples of the phthalocyanine compound include metals such as metal-free phthalocyanine, copper, indium, gallium, tin, titanium, zinc, vanadium, silicon, and germanium, or oxides, halides, hydroxides, alkoxides, and the like. Phthalocyanine and the like.

  The crystal form of the phthalocyanine-based compound is not limited. Particularly, the X-type, τ-type metal-free phthalocyanine, A-type (also known as β-type), B-type (also known as α-type), D, which are highly sensitive crystal types. Type (also called Y type) titanyl phthalocyanine (also known as oxytitanium phthalocyanine), vanadyl phthalocyanine, chloroindium phthalocyanine, chlorogallium phthalocyanine such as type II, hydroxygallium phthalocyanine such as type V, μ-type such as G type and I type Preference is given to oxo-gallium phthalocyanine dimer, μ-oxo-aluminum phthalocyanine dimer such as type II, and the like. Among these phthalocyanines, A-type (β-type), B-type (α-type) and D-type (Y-type) titanyl phthalocyanine, II-type chlorogallium phthalocyanine, V-type hydroxygallium phthalocyanine, G-type μ-oxo-gallium A phthalocyanine dimer and the like are particularly preferable.

  Further, among these phthalocyanine compounds, oxytitanium phthalocyanine having a Bragg angle (2θ ± 0.2 °) of an X-ray diffraction spectrum with respect to CuKα characteristic X-rays of 27.3 ° has a main diffraction peak, 9.3 ° Oxytitanium phthalocyanine showing main diffraction peaks at 13.2 °, 26.2 ° and 27.1 °, at 9.2 °, 14.1 °, 15.3 °, 19.7 ° and 27.1 ° Dihydroxysilicon phthalocyanine with main diffraction peaks, dichloro with main diffraction peaks at 8.5 °, 12.2 °, 13.8 °, 16.9 °, 22.4 °, 28.4 ° and 30.1 ° Tin phthalocyanine, hydroxygallium phthalocyanine showing major diffraction peaks at 7.5 °, 9.9 °, 12.5 °, 16.3 °, 18.6 °, 25.1 ° and 28.3 °, To, 7.4 °, 16.6 °, chlorogallium phthalocyanine preferably exhibits a diffraction peak at 25.5 ° and 28.3 °. Among these, oxytitanium phthalocyanine having a main diffraction peak at 27.3 ° is particularly preferable, and in this case, oxytitanium phthalocyanine having a main diffraction peak at 9.5 °, 24.1 ° and 27.3 ° is particularly preferable. .

  In addition, one kind of charge generating substance may be used alone, or two or more kinds may be used in any combination and ratio. Therefore, the phthalocyanine compound may be a single compound or a mixture or mixed crystal of two or more compounds. As the mixed or mixed crystal state of the phthalocyanine compound here, the respective constituent elements may be mixed and used later, or the mixed state in the production / treatment process of the phthalocyanine compound such as synthesis, pigmentation, crystallization, etc. It may be the one that gave rise to. Examples of such treatment include acid paste treatment, grinding treatment, and solvent treatment. There is no limitation on the method for producing the mixed crystal state. For example, as described in JP-A-10-48859, two kinds of crystals are mechanically ground after mixing and made amorphous, and then subjected to solvent treatment. A method of converting to a specific crystal state is mentioned.

  In addition, when a phthalocyanine compound is used, a charge generation material other than the phthalocyanine compound may be used in combination. For example, charge generating substances such as azo pigments, perylene pigments, quinacridone pigments, polycyclic quinone pigments, indigo pigments, benzimidazole pigments, pyrylium salts, thiapyrylium salts, and squalium salts can be used in combination.

  The charge generation material is dispersed in the photosensitive layer forming coating solution, but may be pre-ground before being dispersed in the photosensitive layer forming coating solution. The pre-grinding can be performed using various apparatuses, but is usually performed using a ball mill, a sand grind mill, or the like. Any grinding media can be used as the grinding media to be fed into these grinding devices as long as the grinding media is not pulverized during the grinding treatment and can be easily separated after the dispersion treatment. Examples thereof include beads and balls such as glass, alumina, zirconia, stainless steel, and ceramics. In the pre-grinding, it is preferred to grind the volume average particle diameter to 500 μm or less, and more preferably to 250 μm or less. The volume average particle diameter of the charge generating material may be measured by any method commonly used by those skilled in the art, but is usually measured by a normal sedimentation method or a centrifugal sedimentation method.

[IV-2. Charge transport material]
There are no restrictions on the charge transport material. Examples of charge transport materials include: polymer compounds such as polyvinyl carbazole, polyvinyl pyrene, polyglycidyl carbazole and polyacenaphthylene; polycyclic aromatic compounds such as pyrene and anthracene; indole derivatives, imidazole derivatives, carbazole derivatives, pyrazoles Heterocyclic compounds such as derivatives, pyrazoline derivatives, oxadiazole derivatives, oxazole derivatives, thiadiazole derivatives; p-diethylaminobenzaldehyde-N, N-diphenylhydrazone, N-methylcarbazole-3-carbaldehyde-N, N-diphenylhydrazone, etc. Hydrazone compounds; styryl compounds such as 5- (4- (di-p-tolylamino) benzylidene) -5H-dibenzo (a, d) cycloheptene; triarylamines such as p-tolylamine Compounds; N, N, N ', N'- benzidine compound of tetraphenyl benzidine; butadiene compounds; di - (p-ditolylaminophenyl) triphenylmethane-based compounds such as methane and the like. Among these, a hydrazone derivative, a carbazole derivative, a styryl compound, a butadiene compound, a triarylamine compound, a benzidine compound, or a combination of them is preferably used. These charge transport materials may be used alone or in combination of two or more in any combination and ratio.

[IV-3. Binder resin for photosensitive layer]
The photosensitive layer according to the electrophotographic photoreceptor of the present invention is formed in a form in which a photoconductive material is bound with various binder resins. As the binder resin for the photosensitive layer, any known binder resin that can be used for an electrophotographic photoreceptor can be used. Specific examples of the binder resin for the photosensitive layer include polymethyl methacrylate, polystyrene, polyvinyl acetate, polyacrylic acid ester, polymethacrylic acid ester, polyester, polyarylate, polycarbonate, polyester polycarbonate, polyvinyl acetal, polyvinyl acetoacetal, polyvinyl propional. , Polyvinyl butyral, polysulfone, polyimide, phenoxy resin, epoxy resin, urethane resin, silicone resin, cellulose ester, cellulose ether, vinyl chloride vinyl acetate copolymer, vinyl chloride such as polyvinyl chloride, and copolymers thereof Used. These partially crosslinked cured products can also be used. In addition, the binder resin for photosensitive layers may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and ratios.

[IV-4. Layer containing charge generation material]
Laminated Photoreceptor When the electrophotographic photoreceptor of the present invention is a so-called laminated photoreceptor, the layer containing a charge generating substance is usually a charge generating layer. However, in the multilayer photoconductor, a charge generating material may be included in the charge transport layer as long as the effects of the present invention are not significantly impaired.

There is no restriction on the volume average particle size of the charge generating material. By the way, the charge generating substance is usually dispersed in the photosensitive layer forming coating solution, but there is no limitation on the dispersion method, and examples thereof include a ball mill dispersion method, an attritor dispersion method, and a sand mill dispersion method. At this time, it is effective to reduce the particle size of the charge generating material in the coating solution for forming the photosensitive layer to 0.5 μm or less, preferably 0.3 μm or less, more preferably 0.15 μm or less.
The thickness of the charge generation layer is arbitrary, but is usually 0.1 μm or more, preferably 0.15 μm or more, and usually 2 μm or less, preferably 0.8 μm or less.

  When the layer containing the charge generation material is a charge generation layer, the use ratio of the charge generation material in the charge generation layer is usually 30 weights with respect to 100 parts by weight of the binder resin for the photosensitive layer contained in the charge generation layer. Part or more, preferably 50 parts by weight or more, and usually 500 parts by weight or less, preferably 300 parts by weight or less. If the amount of the charge generating substance used is too small, the electrical characteristics as an electrophotographic photosensitive member may not be sufficient, and if it is too large, the stability of the coating solution may be impaired.

  Furthermore, in the charge generation layer, known plasticizers for improving film formability, flexibility, mechanical strength, etc., additives for suppressing residual potential, and dispersion aids for improving dispersion stability Further, it may contain a leveling agent, a surfactant, silicone oil, fluorine oil and other additives for improving coating properties. In addition, these additives may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and ratios.

Single-layer type photoconductor When the electrophotographic photoconductor of the present invention is a so-called single-layer type photoconductor, a binder resin for a photosensitive layer and a charge transport material having the same blending ratio as the charge transport layer described later are the main components. The charge generation material is dispersed in a matrix.
When used in a single-layer type photosensitive layer, it is desirable that the particle size of the charge generating material be sufficiently small. For this reason, in the single-layer type photosensitive layer, the volume average particle diameter of the charge generation material is usually 0.5 μm or less, preferably 0.3 μm or less, more preferably 0.15 μm or less.
The thickness of the single-layer type photosensitive layer is arbitrary, but is usually 5 μm or more, preferably 10 μm or more, and usually 50 μm or less, preferably 45 μm or less.

  The amount of the charge generating material dispersed in the photosensitive layer is arbitrary, but if it is too small, sufficient sensitivity may not be obtained, and if it is too much, chargeability and sensitivity may be lowered. is there. Therefore, the content of the charge generating substance in the single-layer type photosensitive layer is usually 0.5% by weight or more, preferably 1.0% by weight or more, and usually 50% by weight or less, preferably 45% by weight or less. is there.

  In addition, the photosensitive layer of the single-layer type photoreceptor is also a known plasticizer for improving film formability, flexibility, mechanical strength, etc., an additive for suppressing residual potential, and an improvement in dispersion stability. It may contain a dispersion aid, a leveling agent for improving coating properties, a surfactant, silicone oil, fluorine oil and other additives. In addition, these additives may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and ratios.

[IV-5. Layer containing charge transport material]
When the electrophotographic photoreceptor of the present invention is a so-called laminated photoreceptor, the layer containing a charge transport material is usually a charge transport layer. The charge transport layer may be formed of a resin having a charge transport function alone, but a configuration in which the charge transport material is dispersed or dissolved in a binder resin for a photosensitive layer is more preferable.
The thickness of the charge transport layer is arbitrary, but is usually 5 μm or more, preferably 10 μm or more, more preferably 15 μm or more, and usually 60 μm or less, preferably 45 μm or less, more preferably 27 μm or less.

  On the other hand, when the electrophotographic photosensitive member of the present invention is a so-called single layer type photosensitive member, the single layer type photosensitive layer has the charge transport material dispersed or dissolved in the binder resin as a matrix in which the charge generating material is dispersed. Configuration is used.

  As the binder resin used in the layer containing the charge transport material, the above-described binder resin for a photosensitive layer can be used. Among them, examples of those particularly suitable for use in a layer containing a charge transport material include vinyl polymers such as polymethyl methacrylate, polystyrene, and polyvinyl chloride, and copolymers thereof, polycarbonate, polyarylate, polyester, polyester carbonate. , Polysulfone, polyimide, phenoxy, epoxy, silicone resin and the like, and partially crosslinked cured products thereof. In addition, this binder resin may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.

  Further, in the charge transport layer and the single-layer type photosensitive layer, the ratio of the binder resin and the charge transport material is arbitrary as long as the effect of the present invention is not significantly impaired, but the charge transport material with respect to 100 parts by weight of the binder resin. Is usually 20 parts by weight or more, preferably 30 parts by weight or more, more preferably 40 parts by weight or more, and usually 200 parts by weight or less, preferably 150 parts by weight or less, more preferably 120 parts by weight or less. The

  Furthermore, the layer containing the charge transport material contains various additives such as an antioxidant such as hindered phenol and hindered amine, an ultraviolet absorber, a sensitizer, a leveling agent, and an electron withdrawing material as necessary. Also good. In addition, these additives may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and ratios.

[IV-6. Other layers]
The electrophotographic photoreceptor of the present invention may have other layers in addition to the above-described undercoat layer and photosensitive layer.
For example, as the outermost surface layer, a conventionally known surface protective layer or overcoat layer mainly composed of a thermoplastic or thermosetting polymer may be provided.

[IV-7. Layer formation method]
There is no limitation on the method of forming each layer other than the undercoat layer of the photoreceptor, and any method can be used. For example, as in the case of forming an undercoat layer with the undercoat layer forming coating solution according to the present invention, a coating solution obtained by dissolving or dispersing a substance contained in the layer in a solvent (photosensitive layer forming coating solution) , A coating solution for forming a charge generation layer, a coating solution for forming a charge transport layer, and the like) are sequentially applied and dried by using known methods such as a dip coating method, a spray coating method, a ring coating method, and the like. . In this case, the coating solution may contain various additives such as a leveling agent, an antioxidant, and a sensitizer for improving the coating property as necessary.

  Although there is no restriction | limiting in the solvent used for a coating liquid, Usually, an organic solvent is used. Examples of preferable solvents include alcohols such as methanol, ethanol, propanol, 1-hexanol, and 1,3-butanediol; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; dioxane, tetrahydrofuran, and ethylene glycol Ethers such as monomethyl ether; ether ketones such as 4-methoxy-4-methyl-2-pentanone; (halo) aromatic hydrocarbons such as benzene, toluene, xylene and chlorobenzene; esters such as methyl acetate and ethyl acetate Amides such as N, N-dimethylformamide and N, N-dimethylacetamide; sulfoxides such as dimethyl sulfoxide. Among these solvents, alcohols, aromatic hydrocarbons, ethers and ether ketones are particularly preferably used. More preferable examples include toluene, xylene, 1-hexanol, 1,3-butanediol, tetrahydrofuran, 4-methoxy-4-methyl-2-pentanone, and the like.

The said solvent may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio. Examples of solvents that are particularly preferably used in combination of two or more include ethers, alcohols, amides, sulfoxides, sulfoxides, ether ketones, etc., among which 1,2-dimethoxyethane is preferred. And ethers such as 1-propanol and the like are suitable. Particularly preferred are ethers. This is particularly from the standpoints of crystal form stabilizing ability and dispersion stability of phthalocyanine when a coating solution is produced using oxytitanium phthalocyanine as a charge generating substance.
In addition, there is no restriction | limiting in the quantity of the solvent used for a coating liquid, What is necessary is just to use an appropriate quantity according to a composition, a coating method, etc. of a coating liquid.

[V. Advantages of electrophotographic photosensitive member of the present invention]
The electrophotographic photoreceptor of the present invention can obtain a good image without causing image defects such as black spots, color spots, and black streaks while preventing fringes due to interference of exposure light. In addition, the following advantages may be obtained.
That is, it is possible to form a high-quality image even under various usage environments, and it is excellent in durability stability. Therefore, when the electrophotographic photosensitive member of the present invention is used for image formation, it is possible to form a high-quality image while suppressing the influence of the environment.
Further, in the conventional electrophotographic photoreceptor, the undercoat layer contains coarse metal oxide particles in which oxide particles are aggregated, and the coarse metal oxide particles may cause defects during image formation. It was. Further, when a contact type is used as the charging means, when the photosensitive layer is charged, the charge is transferred from the photosensitive layer to the conductive substrate through the metal oxide particles, and the charging is appropriately performed. There was also a possibility that could not be. However, since the electrophotographic photosensitive member of the present invention includes an undercoat layer using metal oxide particles having a very small average particle diameter and a good particle size distribution, defects and appropriate charging can be appropriately performed. It is possible to suppress the inability to do so, and high quality image formation is possible.

[VI. Image forming apparatus]
Next, an embodiment of an image forming apparatus using the electrophotographic photosensitive member of the present invention (image forming apparatus of the present invention) will be described with reference to FIG. However, the embodiment is not limited to the following description, and can be arbitrarily modified without departing from the gist of the present invention.

  As shown in FIG. 11, the image forming apparatus includes an electrophotographic photosensitive member 201, a charging device (charging means) 202, an exposure device (exposure means; image exposure means) 203, a developing device (developing means) 204, and a transfer device (transfer). Means) 205, and further, a cleaning device (cleaning means) 206 and a fixing device (fixing means) 207 are provided as necessary.

  In the image forming apparatus of the present invention, the electrophotographic photosensitive member of the present invention described above is provided as the photosensitive member 201. That is, the image forming apparatus of the present invention comprises an electrophotographic photosensitive member, a charging means for charging the electrophotographic photosensitive member, and image exposure for performing image exposure on the charged electrophotographic photosensitive member to form an electrostatic latent image. An image forming apparatus comprising: a developing unit that develops the electrostatic latent image with toner; and a transfer unit that transfers the toner to a transfer target. An electrophotographic photosensitive member having an undercoat layer containing metal oxide particles and a binder resin on a conductive substrate having Rz of 0.8 ≦ Rz ≦ 2 μm, and a photosensitive layer formed on the undercoat layer. The volume average measured by a dynamic light scattering method of the metal oxide particles in a liquid in which the undercoat layer is dispersed in a solvent in which methanol and 1-propanol are mixed at a weight ratio of 7: 3. The particle diameter is 0.1 μm or less and A product having a 90% particle diameter of 0.3 μm or less is provided.

  The electrophotographic photosensitive member 201 is not particularly limited as long as it is the above-described electrophotographic photosensitive member of the present invention. In FIG. 11, as an example, a drum shape in which the photosensitive layer described above is formed on the surface of a cylindrical conductive substrate. The photoconductor is shown. A charging device 202, an exposure device 203, a developing device 204, a transfer device 205, and a cleaning device 206 are arranged along the outer peripheral surface of the electrophotographic photosensitive member 201.

  The charging device 202 charges the electrophotographic photosensitive member 201 and uniformly charges the surface of the electrophotographic photosensitive member 201 to a predetermined potential. In order to effectively utilize the effects of the present invention, the charging device is preferably disposed in contact with the electrophotographic photoreceptor 201. In FIG. 11, a roller-type charging device (charging roller) is shown as an example of the charging device 202, but other than that, a corona charging device such as a corotron and a scorotron, a contact charging device such as a charging brush, and the like are often used.

  In many cases, the electrophotographic photosensitive member 201 and the charging device 202 are designed to be removable from the main body of the image forming apparatus as a cartridge including both of them (hereinafter referred to as a photosensitive cartridge as appropriate). For example, when the electrophotographic photosensitive member 201 or the charging device 202 deteriorates, the photosensitive member cartridge can be detached from the main body of the image forming apparatus, and another new photosensitive member cartridge can be mounted on the main body of the image forming apparatus. ing. Also, the toner described later is often stored in the toner cartridge and designed to be removable from the main body of the image forming apparatus. When the toner in the used toner cartridge runs out, this toner cartridge is removed. It can be removed from the main body of the image forming apparatus and another new toner cartridge can be mounted. Further, a cartridge equipped with all of the electrophotographic photosensitive member 201, the charging device 202, and toner may be used.

  The type of exposure apparatus 203 is not particularly limited as long as it can perform exposure (image exposure) on the electrophotographic photosensitive member 201 to form an electrostatic latent image on the photosensitive surface of the electrophotographic photosensitive member 201. Absent. Specific examples include halogen lamps, fluorescent lamps, lasers such as semiconductor lasers and He—Ne lasers, and LEDs (light emitting diodes). Further, exposure may be performed by a photoreceptor internal exposure method. The light used for the exposure is arbitrary. For example, if the exposure is performed with monochromatic light having a wavelength of 780 nm, monochromatic light having a wavelength of 600 nm to 700 nm, slightly short wavelength, monochromatic light having a wavelength of 350 nm to 600 nm, or the like. Good. Among these, it is preferable to expose with monochromatic light having a short wavelength of 350 nm to 600 nm, and more preferably to expose with monochromatic light having a wavelength of 380 nm to 500 nm.

  The developing device 204 develops the electrostatic latent image. The type is not particularly limited, and any apparatus such as a dry development system such as cascade development, one-component conductive toner development, two-component magnetic brush development, or a wet development system can be used. In FIG. 11, the developing device 204 includes a developing tank 241, an agitator 242, a supply roller 243, a developing roller 244, and a regulating member 245, and is configured to store toner T inside the developing tank 241. . Further, a replenishing device (not shown) for replenishing toner T may be attached to the developing device 204 as necessary. The replenishing device is configured to be able to replenish toner T from a container such as a bottle or a cartridge.

  The supply roller 243 is formed from a conductive sponge or the like. The developing roller 244 is made of a metal roll such as iron, stainless steel, aluminum, or nickel, or a resin roll obtained by coating such a metal roll with a silicone resin, a urethane resin, a fluorine resin, or the like. The surface of the developing roller 244 may be smoothed or roughened as necessary.

  The developing roller 244 is disposed between the electrophotographic photosensitive member 201 and the supply roller 243, and is in contact with the electrophotographic photosensitive member 201 and the supply roller 243, respectively. The supply roller 243 and the developing roller 244 are rotated by a rotation drive mechanism (not shown). The supply roller 243 carries the stored toner T and supplies it to the developing roller 244. The developing roller 244 carries the toner T supplied by the supply roller 243 and brings it into contact with the surface of the electrophotographic photosensitive member 201.

  The regulating member 245 is formed of a resin blade such as a silicone resin or a urethane resin, a metal blade such as stainless steel, aluminum, copper, brass, phosphor bronze, or a blade obtained by coating such a metal blade with a resin. The regulating member 245 contacts the developing roller 244 and is pressed with a predetermined force against the developing roller 244 side by a spring or the like (a general blade linear pressure is 5 to 500 g / cm). If necessary, the regulating member 245 may be provided with a function of imparting charging to the toner T by frictional charging with the toner T.

  The agitator 242 is rotated by a rotation driving mechanism, and agitates the toner T and conveys the toner T to the supply roller 243 side. A plurality of agitators 242 may be provided with different blade shapes and sizes.

  The type of the toner T is arbitrary, and in addition to the powdery toner, a polymerized toner using a suspension polymerization method, an emulsion polymerization method, or the like can be used. In particular, when a polymerized toner is used, a toner having a small particle diameter of about 4 to 8 μm is preferable, and the toner particles are used in a variety of shapes ranging from a nearly spherical shape to a potato-like spherical shape. be able to. The polymerized toner is excellent in charging uniformity and transferability and is suitably used for high image quality.

  The type of the transfer device 205 is not particularly limited, and an apparatus using an arbitrary system such as an electrostatic transfer method such as corona transfer, roller transfer, or belt transfer, a pressure transfer method, or an adhesive transfer method can be used. . Here, it is assumed that the transfer device 205 includes a transfer charger, a transfer roller, a transfer belt, and the like disposed so as to face the electrophotographic photosensitive member 201. The transfer device 205 applies a predetermined voltage value (transfer voltage) having a polarity opposite to the charging potential of the toner T, and transfers a toner image formed on the electrophotographic photosensitive member 201 to a transfer material (transfer object, paper, medium). Transfer to P. The present invention is effective when the transfer device 205 is placed in contact with the photosensitive member via a transfer material.

  There is no restriction | limiting in particular about the cleaning apparatus 206, Arbitrary cleaning apparatuses, such as a brush cleaner, a magnetic brush cleaner, an electrostatic brush cleaner, a magnetic roller cleaner, a blade cleaner, can be used. The cleaning device 206 scrapes the residual toner adhering to the photoconductor 201 with a cleaning member and collects the residual toner. However, when there is little or almost no toner remaining on the surface of the photoreceptor, the cleaning device 206 may be omitted.

  The fixing device 207 includes an upper fixing member (fixing roller) 271 and a lower fixing member (fixing roller) 272, and a heating device 273 is provided inside the fixing member 271 or 272. FIG. 11 shows an example in which a heating device 273 is provided inside the upper fixing member 271. As the upper and lower fixing members 271 and 272, a known heat fixing member such as a fixing roll in which a metal base tube such as stainless steel or aluminum is coated with silicon rubber, a fixing roll coated with a fluororesin, or a fixing sheet is used. be able to. Further, the fixing members 271 and 272 may be configured to supply a release agent such as silicone oil in order to improve the releasability, or may be configured to forcibly apply pressure to each other by a spring or the like.

When the toner transferred onto the recording paper P passes between the upper fixing member 271 and the lower fixing member 272 heated to a predetermined temperature, the toner is heated to a molten state and cooled after passing through the recording paper P. Toner is fixed on P.
The type of the fixing device is not particularly limited, and a fixing device of any type such as heat roller fixing, flash fixing, oven fixing, pressure fixing, etc. can be provided including those used here.

In the electrophotographic apparatus configured as described above, an image is recorded as follows. That is, first, the surface (photosensitive surface) of the photoconductor 201 is charged to a predetermined potential (for example, −600 V) by the charging device 202. At this time, charging may be performed by a DC voltage, or charging may be performed by superimposing an AC voltage on the DC voltage.
Subsequently, the photosensitive surface of the charged photoconductor 201 is exposed by the exposure device 203 according to the image to be recorded, and an electrostatic latent image is formed on the photosensitive surface. The developing device 204 develops the electrostatic latent image formed on the photosensitive surface of the photoconductor 201.

The developing device 204 thins the toner T supplied by the supply roller 243 with a regulating member (developing blade) 245 and has a predetermined polarity (here, the same polarity as the charging potential of the photoconductor 201 and a negative polarity). ) And is carried while being carried on the developing roller 244 and brought into contact with the surface of the photosensitive member 201.
When the charged toner T carried on the developing roller 244 contacts the surface of the photoconductor 201, a toner image corresponding to the electrostatic latent image is formed on the photoconductive surface of the photoconductor 201. This toner image is transferred onto the recording paper P by the transfer device 205. Thereafter, the toner remaining on the photosensitive surface of the photoconductor 201 without being transferred is removed by the cleaning device 206.

After the transfer of the toner image onto the recording paper P, the final image is obtained by passing the fixing device 207 and thermally fixing the toner image onto the recording paper P.
In addition to the above-described configuration, the image forming apparatus may have a configuration capable of performing, for example, a static elimination process. The neutralization step is a step of neutralizing the electrophotographic photosensitive member by exposing the electrophotographic photosensitive member, and a fluorescent lamp, an LED, or the like is used as the neutralizing device. In addition, the light used in the static elimination process is often light having an exposure energy that is at least three times that of the exposure light.

  The image forming apparatus may be further modified. For example, the image forming apparatus may be configured to perform a pre-exposure process, an auxiliary charging process, or the like, or may be configured to perform offset printing. A full-color tandem system configuration using toner may be used.

  When the photosensitive member 201 is configured as a cartridge in combination with the charging device 202 as described above, it is preferable that the photosensitive member 201 further includes a developing device 204. Further, in addition to the photosensitive member 201, if necessary, combined with one or more of a charging device 202, an exposure device 203, a developing device 204, a transfer device 205, a cleaning device 206, and a fixing device 207. In this case, the cartridge may be configured as an integrated cartridge (electrophotographic cartridge), and the electrophotographic cartridge may be detachable from a main body of an electrophotographic apparatus such as a copying machine or a laser beam printer. That is, the electrophotographic cartridge of the present invention includes an electrophotographic photosensitive member, a charging unit for charging the electrophotographic photosensitive member, and an image exposing unit for performing image exposure on the charged electrophotographic photosensitive member to form an electrostatic latent image. A developing unit that develops the electrostatic latent image with toner, a transfer unit that transfers the toner to a transfer target, a fixing unit that fixes the toner transferred to the transfer target, and an electrophotographic photosensitive member An electrophotographic cartridge comprising at least one cleaning means for collecting the toner, wherein the electrophotographic photosensitive member has a surface having a maximum height roughness Rz of 0.8 ≦ Rz ≦ 2 μm. And an undercoat layer containing metal oxide particles and a binder resin, and a photosensitive layer formed on the undercoat layer, wherein the undercoat layer comprises methanol and 1-propanol. The volume average particle diameter of the metal oxide particles in the liquid dispersed in the solvent mixed at a weight ratio of 7: 3 is 0.1 μm or less, and the cumulative 90 is measured by the dynamic light scattering method. % Particle diameter is 0.3 μm or less.

  In this case, similarly to the cartridge described in the above embodiment, for example, when the electrophotographic photosensitive member 101 or other member deteriorates, the electrophotographic cartridge is detached from the image forming apparatus main body, and another new electrophotographic cartridge is imaged. By attaching to the forming apparatus main body, maintenance and management of the image forming apparatus is facilitated.

  According to the image forming apparatus and the electrophotographic cartridge of the present invention, a high quality image can be formed. In particular, conventionally, when the transfer device 5 is placed in contact with the photoconductor via a transfer material, image quality is likely to deteriorate. However, the image forming apparatus and the electrophotographic cartridge of the present invention have such quality deterioration. This is effective because there is little possibility of occurrence.

  EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated more concretely, this invention is not limited to these, unless it deviates from the summary. In the description of Examples, “part” means “part by weight” unless otherwise specified.

[Example 1]
[Substrate 1]
Substrate made of A6063 aluminum alloy defined by JIS H4040 with an outer diameter of 30 mm, a length of 357 mm, and a thickness of 1.0 mm by cutting using a polycrystalline diamond tool so that the maximum height roughness Rz is 1.3 μm 1 was produced. Further, a part of the manufactured substrate 1 was left, and the in-plane arithmetic average roughness Ra, the maximum height roughness Rz, and the kurtosis Rku of the substrate 1 were measured by using the left one. As a specific measuring method, a surface roughness measuring instrument “Surfcom 480A” manufactured by Tokyo Seimitsu Co., Ltd. was used, and the numerical values measured in accordance with JIS B0601: 1994 were read as defined in JIS B0601: 2001. The results are shown in Table 3.

[Coating liquid for undercoat layer]
A rutile type titanium oxide having an average primary particle diameter of 40 nm (“TTO55N” manufactured by Ishihara Sangyo Co., Ltd.) and 3% by weight of methyldimethoxysilane (“TSL8117” manufactured by Toshiba Silicone Co., Ltd.) with respect to the titanium oxide were added to a Henschel mixer. 1 kg of a raw slurry obtained by mixing 50 parts of surface-treated titanium oxide obtained by mixing with 120 parts of methanol, and using a zirconia bead having a diameter of about 100 μm (YTZ manufactured by Nikkato Co., Ltd.) as a dispersion medium, a mill volume of about 0 Using a 15-liter Ultra Apex Mill (UAM-015 type) manufactured by Kotobuki Kogyo Co., Ltd., a titanium oxide dispersion was prepared by dispersing for 1 hour in a liquid circulation state with a rotor peripheral speed of 10 m / second and a liquid flow rate of 10 kg / hour. .

  The titanium oxide dispersion, a mixed solvent of methanol / 1-propanol / toluene, and ε-caprolactam [compound represented by the following formula (A)] / bis (4-amino-3-methylcyclohexyl) methane [the following formula Compound represented by (B)] / hexamethylenediamine [compound represented by the following formula (C)] / decamethylene dicarboxylic acid [compound represented by the following formula (D)] / octadecamethylene dicarboxylic acid [following formula (E After the polyamide pellets are dissolved by stirring and mixing the pellets of the copolymerized polyamide having a composition molar ratio of 60% / 15% / 5% / 15% / 5%] , Ultrasonic dispersion with an ultrasonic generator with an output of 1200 W is performed for 1 hour, and a PTFE membrane filter (a) with a pore diameter of 5 μm The weight ratio of the surface-treated titanium oxide / copolymerized polyamide was 3/1, and the weight ratio of the mixed solvent of methanol / 1-propanol / toluene was 7/1/2. Thus, an undercoat layer forming coating solution A having a solid content concentration of 18.0% by weight was obtained.

  Table 2 shows the particle size distribution (volume average particle size and cumulative 90% particle size) of the undercoat layer forming coating solution A measured using the UPA.

  The undercoat layer forming coating solution A was applied onto the substrate 1 by dip coating so that the film thickness after drying was 1.5 μm, and dried to form an undercoat layer. When the surface of the undercoat layer was observed with a scanning electron microscope, almost no aggregates were observed.

[Coating liquid for charge generation layer]
As a charge generation material, 20 parts by weight of oxytitanium phthalocyanine having a powder X-ray diffraction spectrum pattern with respect to CuKα characteristic X-rays shown in FIG. 12 and 280 parts by weight of 1,2-dimethoxyethane are mixed, and are mixed in a sand grind mill for 2 hours. Dispersion treatment was performed to prepare a dispersion. Subsequently, this dispersion, 10 parts by weight of polyvinyl butyral (manufactured by Denki Kagaku Kogyo Co., Ltd., trade name “Denkabutyral” # 6000C), 253 parts by weight of 1,2-dimethoxyethane, and 85 parts by weight of 4-methoxy After mixing -4-methylpentanone-2, further mixing 234 parts by weight of 1,2-dimethoxyethane, treating with an ultrasonic disperser, a PTFE membrane filter having a pore size of 5 μm (Mytecs LC manufactured by Advantech) Then, a charge generation layer coating solution 1 was prepared. This charge generation layer coating solution 1 was applied and dried by dip coating on the undercoat layer such that the film thickness after drying was 0.4 μm to form a charge generation layer.

[Coating liquid for charge transport layer]
Next, on this charge generation layer, 56 parts of the hydrazone compound shown below,

14 parts of a hydrazone compound shown below,

100 parts of a polycarbonate resin (viscosity average molecular weight of about 40,000) having the following repeating structure;

A charge transport layer coating solution in which 0.05 part by weight of silicone oil was dissolved in 640 parts by weight of a tetrahydrofuran / toluene (8/2) mixed solvent was applied so that the film thickness after drying was 17 μm. And air dried for 25 minutes.
Further, it was dried at 125 ° C. for 20 minutes to provide a charge transport layer to produce an electrophotographic photoreceptor. This electrophotographic photosensitive member is referred to as a photosensitive member P1.

  A flange member for driving was attached to the photoreceptor P1 obtained in this way, and it was incorporated into a cartridge of a monochrome laser beam printer LBP-850 manufactured by Canon, an image was formed, and image evaluation was performed visually. The results are shown in Table 3. In Table 3, each of the interference fringes, black spots, and black stripes was “◯” when there was no interference, “△” when it was confirmed but acceptable in use, and was unacceptable in use. In this case, “×” is displayed.

[Example 2]
Nylon material with alumina abrasive grains with a diameter of 0.45 mm and a particle size of # 500 (average particle diameter of 34 μm) (made by DuPont), drilled in a zigzag shape with a hole diameter of 5 mm and a hole interval of 10 mm on a PVC cylindrical base with an outer diameter of φ60 mm Using a brush planted to have a length of 25 mm ("Tinex A"), a mirror cutting tube made of A6063 aluminum alloy (Ra0.30) defined by JIS H4040 having an outer diameter of 30 mm, a length of 357 mm, and a thickness of 1.0 mm. 03 Rz 0.2), surface roughening was performed under the conditions of a substrate rotation speed of 200 rpm, a brush rotation speed of 750 rpm, a contact allowance of 10 mm, a lifting speed of 5 mm / second, and a sprinkling water amount of 1 L / min. Here, the pulling speed was set to be as fast as possible so that the density of the grooves was not sparse.

  Next, the roughened tube was washed. First, it is immersed for 5 minutes in a 60 ° C solution in which a degreasing agent “NG-30” manufactured by Kizai Co., Ltd. is dissolved at a concentration of 4% by weight, and then sequentially immersed in room temperature pure water consisting of 3 tanks for 1 minute each. After removing the degreasing agent, it was dipped in pure water at 82 ° C. for 10 seconds, pulled up at a speed of 10 mm / second, and dried with hot water. Finally, finish drying was performed in a clean oven at 150 ° C. for 10 minutes, and the mixture was allowed to cool to room temperature. As a result, a substrate 2 having curved and discontinuous, diagonal lattice-like grooves as shown in FIG. 3 was obtained on the surface of the substrate.

A part of the substrate 2 formed in this manner is set aside for measuring the surface roughness and groove width, and an undercoat layer and a photosensitive layer are formed on the substrate 2 after another cleaning in the same manner as in Example 1 to obtain a photoreceptor. P2 was obtained.
Using the photoreceptor P2 thus obtained, an image was formed in the same manner as in Example 1, and image evaluation was performed visually. The results are shown in Table 3.
Further, the in-plane arithmetic average roughness Ra, the maximum height roughness Rz, and the kurtosis Rku of the substrate 2 that had been set aside were measured in the same manner as in Example 1. Further, the maximum value (horizontal groove maximum value) and minimum value (horizontal groove minimum value) of the groove width L of the groove formed on the surface of the substrate 2 were observed and photographed with an optical microscope, respectively (400 times). It was measured. The results are also shown in Table 3.

[Example 3]
Surface roughening was performed in the same manner as in Example 2 except that a squeezing tube made of A3003 aluminum alloy defined in JIS H4040 having an outer diameter of 30 mm, a length of 357 mm, and a thickness of 1.0 mm was obtained to obtain a substrate 3. .
A part of the substrate 3 formed in this manner was set aside for measuring the surface roughness and groove width, and a photosensitive layer was formed on the substrate 3 after another cleaning in the same manner as in Example 1 to obtain a photoreceptor P3. .
Using the photoreceptor P3 thus obtained, an image was formed in the same manner as in Example 1, and image evaluation was performed visually. The results are shown in Table 3.
In the same manner as in Example 2, the in-plane arithmetic average roughness Ra, the maximum height roughness Rz, and the kurtosis Rku of the substrate 3 that had been set aside were measured. Further, the maximum value (lateral groove maximum value) and the minimum value (lateral groove minimum value) of the groove width L of the grooves formed on the surface of the substrate 3 were measured. The results are also shown in Table 3.

[Example 4]
JIS H4040 with outer diameter φ30 mm × length 357 mm × thickness 1.0 mm, which was ground to Rz 1.0 μm using a centerless grinding machine in the same manner as described in JP-A-7-43922. The A3003 aluminum alloy grinding tube specified in JIS No.1 is made of nylon material containing alumina abrasive grains ("Sangrit" manufactured by Asahi Kasei Co., Ltd.) with a diameter of 0.3 mm and a particle size of # 500 (average particle size of 34 μm). The surface roughening conditions were the same as in Example 1 except that the substrate rotation speed was 250 rpm, the brush rotation speed was 750 rpm, the contact allowance was 6 mm, the lifting speed was 5 mm / second, and the sprinkling water amount was 1 L / min. As shown in FIG. 3, curved and discontinuous, oblique grooves were formed to obtain a substrate 4.

A part of the substrate 4 formed in this manner was set aside for measuring the surface roughness and groove width, and a photosensitive layer was formed on the substrate 4 after another cleaning in the same manner as in Example 1 to obtain a photoreceptor P4. .
Using the photoreceptor P4 thus obtained, an image was formed in the same manner as in Example 1, and image evaluation was performed visually. The results are shown in Table 3.
Further, in the same manner as in Example 2, the in-plane arithmetic average roughness Ra, maximum height roughness Rz, and kurtosis Rku of the substrate 4 that had been set aside were measured. Further, the maximum value (maximum value of the transverse groove) and the minimum value (minimum value of the transverse groove) of the groove width L of the groove formed on the surface of the substrate 4 were measured. The results are also shown in Table 3.

[Example 5]
A mirror cutting tube (Ra = 0.03 μm; Rz = 0.2 μm) made of A3003 aluminum alloy defined in JIS H4040 having an outer diameter of 30 mm × length of 357 mm × thickness of 1.0 mm is disclosed in Japanese Patent Laid-Open No. 5-216261. A dry honing treatment was performed in the same manner as described in Example 4.
The base material is a nylon material containing alumina abrasive grains having a diameter of 0.3 mm and a particle size of # 1000 (average particle size of 16 μm) (“Sangrit” manufactured by Asahi Kasei Co., Ltd.). Except for the conditions of substrate rotation speed 250 rpm, brush rotation speed 750 rpm, contact allowance 6 mm, pulling speed 10 mm / sec, sprinkling water amount 1 L / min, the surface of the substrate as shown in FIG. Discontinuous and oblique grooves were formed to obtain the substrate 5.

A part of the substrate 5 thus formed was set aside for measuring the surface roughness and the groove width, and a photosensitive layer was formed on a tube after another cleaning in the same manner as in Example 1 to obtain a photoreceptor P5.
Using the photoreceptor P5 thus obtained, an image was formed in the same manner as in Example 1, and image evaluation was performed visually. The results are shown in Table 3.
Further, in the same manner as in Example 2, the in-plane arithmetic average roughness Ra, maximum height roughness Rz, and kurtosis Rku of the substrate 5 that had been set aside were measured. Furthermore, the maximum value (maximum value of the transverse groove) and the minimum value (minimum value of the transverse groove) of the groove width L of the groove formed on the surface of the substrate 5 were measured. The results are also shown in Table 3.

[Example 6]
An A3003 aluminum alloy ironing tube defined by JIS H4040 with an outer diameter of 30 mm, length of 357 mm and thickness of 1.0 mm is used. The brush material is alumina with a diameter of 0.3 mm and a particle size of # 1000 (average particle size of 16 μm). A nylon material containing abrasive grains ("Sangrit" manufactured by Asahi Kasei Co., Ltd.) was used, and the roughening conditions were as follows: substrate rotation speed 300 rpm, brush rotation speed 100 rpm, contact allowance 4 mm, pulling speed 1 mm / second, sprinkling water amount 1 L / The substrate 6 was obtained in the same manner as in Example 1 except that the conditions were for minutes, and a curved and discontinuous, oblique groove as shown in FIG. 2 was formed on the surface of the substrate.

  A part of this base 6 was left, and the left base 6 was used in the same manner as in Example 2 to calculate the in-plane arithmetic average roughness Ra, maximum height roughness Rz, kurtosis Rku, and base 6 The maximum value (horizontal groove maximum value) and the minimum value (horizontal groove minimum value) of the groove width L of the grooves formed on the surface were measured. The results are shown in Table 3.

  A coating liquid B for forming an undercoat layer was prepared in the same manner as in Example 1 except that zirconia beads having a diameter of about 50 μm (YTZ manufactured by Nikkato Co., Ltd.) were used as a dispersion medium when dispersed by an ultra apex mill. The physical properties were measured in the same manner as in Example 1. The results are shown in Table 2.

The undercoat layer forming coating solution B was applied onto the substrate 6 by dip coating so that the film thickness after drying was 2 μm and dried to form an undercoat layer. When the surface of the undercoat layer was observed with a scanning electron microscope, almost no aggregates were observed.
94.2 cm ^{2 of} this undercoat layer was immersed in a mixed solution of 70 g of methanol and 30 g of 1-propanol, and subjected to ultrasonic treatment for 5 minutes by an ultrasonic oscillator with an output of 600 W to obtain an undercoat layer dispersion. When the particle size distribution of the metal oxide particles therein was measured by UPA in the same manner as in Example 1, the volume average particle size was 0.09 μm, and the cumulative 90% particle size was 0.14 μm.

A charge generation layer and a charge transport layer were formed on the undercoat layer in the same manner as in Example 1 to obtain a photoreceptor P6.
After 94.2 cm ² of the photosensitive layer of this photoreceptor P6 was immersed in 100 cm ³ of tetrahydrofuran and dissolved and removed by ultrasonic treatment for 5 minutes with an ultrasonic oscillator with an output of 600 W, the same part was made up of 70 g of methanol and 30 g of 1-propanol. It is immersed in the mixed solution and subjected to ultrasonic treatment with an ultrasonic oscillator with an output of 600 W for 5 minutes to obtain a subbing layer dispersion, and the particle size distribution of the metal oxide particles in the dispersion is determined by UPA as in Example 1. When measured, the volume average particle size was 0.09 μm, and the cumulative 90% particle size was 0.14 μm.

  Using the photoreceptor P6 thus obtained, an image was formed in the same manner as in Example 1, and image evaluation was performed visually. The results are shown in Table 3.

[Example 7]
A coating liquid C for forming an undercoat layer was prepared in the same manner as in Example 6 except that the rotor peripheral speed at the time of dispersing with an ultra apex mill was set to 12 m / sec. The physical properties were measured in the same manner as in Example 1. . The results are shown in Table 2.

  The undercoat layer forming coating solution C was applied onto the substrate 3 by dip coating so that the film thickness after drying was 2 μm and dried to form an undercoat layer. When the surface of the undercoat layer was observed with a scanning electron microscope, almost no aggregates were observed.

A charge generation layer and a charge transport layer were formed on the undercoat layer in the same manner as in Example 1 to obtain a photoreceptor P7.
Using the photoreceptor P7 thus obtained, an image was formed in the same manner as in Example 1, and image evaluation was performed visually. The results are shown in Table 3.

[Example 8]
Using an ironing tube made of A3003 aluminum alloy specified in JIS H4040 with an outer diameter of 30 mm x length of 357 mm x thickness of 1.0 mm, the brush material is alumina with a diameter of 0.4 mm and a particle size of # 800 (average particle size of 20 μm) A nylon material containing abrasive grains ("Tregrit" manufactured by Toray Monofilament Co., Ltd.), and the roughening conditions were as follows: substrate rotation speed 250 rpm, brush rotation speed 750 rpm, contact allowance 6 mm, pulling speed 8 mm / second, sprinkling water amount 1 L / The substrate 7 was obtained in the same manner as in Example 1 except that the conditions were for minutes, and a curved and discontinuous, oblique groove as shown in FIG. 3 was formed on the surface of the substrate.

  A part of the base body 7 was left, and the left base 7 was used in the same manner as in Example 2 to calculate the in-plane arithmetic average roughness Ra, the maximum height roughness Rz, the kurtosis Rku, and the base 7 The maximum value (horizontal groove maximum value) and the minimum value (horizontal groove minimum value) of the groove width L of the grooves formed on the surface were measured. The results are shown in Table 3.

  A coating liquid D for forming an undercoat layer was prepared in the same manner as in Example 7 except that zirconia beads having a diameter of about 30 μm (YTZ manufactured by Nikkato Co., Ltd.) were used as a dispersion medium when dispersed with an ultra apex mill. The physical properties were measured in the same manner as in Example 1. The results are shown in Table 2.

The undercoat layer forming coating solution D was applied onto the substrate 7 by dip coating so that the film thickness after drying was 2 μm and dried to form an undercoat layer. When the surface of the undercoat layer was observed with a scanning electron microscope, almost no aggregates were observed.
A charge generation layer and a charge transport layer were formed on the undercoat layer in the same manner as in Example 1 to obtain a photoreceptor P8.
Using the photoreceptor P8 thus obtained, an image was formed in the same manner as in Example 1, and image evaluation was performed visually. The results are shown in Table 3.

[Example 9]
Using an ironing tube made of A3003 aluminum alloy specified in JIS H4040 with an outer diameter of 30 mm x length of 357 mm x thickness of 1.0 mm, the brush material is alumina of diameter φ0.45 mm and particle size # 500 (average particle size 340 μm) A nylon material containing abrasive grains ("Sangrit" manufactured by Asahi Kasei Co., Ltd.) was used. The roughening conditions were as follows: substrate rotation speed 250 rpm, brush rotation speed 750 rpm, contact allowance 6 mm, pulling speed 10 mm / sec, sprinkling water amount 1 L / The substrate 8 was obtained in the same manner as in Example 1 except that the conditions were for minutes, and a curved and discontinuous, oblique groove as shown in FIG. 3 was formed on the surface of the substrate.

  A part of the substrate 8 was left, and the left-hand side was used in the same manner as in Example 2 to calculate the in-plane arithmetic average roughness Ra, the maximum height roughness Rz, the kurtosis Rku, and the substrate 8. The maximum value (horizontal groove maximum value) and the minimum value (horizontal groove minimum value) of the groove width L of the grooves formed on the surface were measured. The results are shown in Table 3.

The undercoat layer forming coating solution D was applied onto the substrate 8 by dip coating so that the film thickness after drying was 2 μm and dried to form an undercoat layer. When the surface of the undercoat layer was observed with a scanning electron microscope, almost no aggregates were observed.
A charge generation layer and a charge transport layer were formed on the undercoat layer in the same manner as in Example 1 to obtain a photoreceptor P9.
Using the photoreceptor P9 thus obtained, an image was formed in the same manner as in Example 1 and image evaluation was performed visually. The results are shown in Table 3.

[Example 10]
Surface roughening was carried out in the same manner as in Example 2 using an A3003 aluminum alloy substrate defined in JIS H4040 having an outer diameter of 30 mm, a length of 346 mm, and a thickness of 1.0 mm.
A part of the substrate 9 is left, and the substrate 9 is used, in the same manner as in Example 2, the in-plane arithmetic average roughness Ra, the maximum height roughness Rz, the kurtosis Rku, and the substrate 9 The maximum value (horizontal groove maximum value) and the minimum value (horizontal groove minimum value) of the groove width L of the grooves formed on the surface were measured. The results are shown in Table 3.

  The undercoat layer forming coating solution D was applied onto the substrate 9 by dip coating so that the film thickness after drying was 2 μm and dried to form an undercoat layer. When the surface of the undercoat layer was observed with a scanning electron microscope, almost no aggregates were observed.

Next, on this charge generation layer, a composition (A) produced by the production method described in Example 1 of JP-A-2002-080432, which mainly comprises a structure represented by the following formula as a charge transport material: 60 copies,

100 parts of a polycarbonate resin having the following repeating structure (viscosity average molecular weight of about 30,000),

A coating solution prepared by dissolving 0.05 part by weight of silicone oil in 640 parts by weight of a tetrahydrofuran / toluene (8/2) mixed solvent is applied so that the film thickness after drying becomes 10 μm, and dried to charge transport. The layer was provided to prepare an electrophotographic photoreceptor P10.

  The produced photoreceptor P10 is mounted on a cartridge of a copying machine (product name: Workio DP1820) manufactured by Panasonic Communication Co., Ltd. (as an integrated cartridge, having a two-component toner, a scorotron charging member, and a blade cleaning member), and an image is obtained. When formed, a good image could be obtained.

[Example 11]
A substrate 10 was obtained in the same manner as in Example 10 except that the pulling rate was 1.3 mm / sec.
A part of this substrate 10 was left, and the left one was used in the same manner as in Example 2 to calculate the in-plane arithmetic average roughness Ra, the maximum height roughness Rz, the kurtosis Rku, and the substrate 10. The maximum value (horizontal groove maximum value) and the minimum value (horizontal groove minimum value) of the groove width L of the grooves formed on the surface were measured. The results are shown in Table 3.

A photosensitive layer was formed on the substrate 10 in the same manner as in Example 10 to obtain a photoreceptor P11.
When the produced photoreceptor P11 was mounted on a cartridge of a copying machine (product name: Workio DP1820) manufactured by Panasonic Communication Co., Ltd. and an image was formed, a good image could be obtained.

[Example 12]
Using an A3003 aluminum alloy ironing tube defined in JIS H4040 with an outer diameter of 30 mm, a length of 388 mm, and a thickness of 0.75 mm, a roughening treatment was performed in the same manner as in Example 2, and the surface of the substrate is shown in FIG. Such a curved and discontinuous, oblique groove was formed to obtain the substrate 11.
A part of this base 11 was left, and the left side of the base 11 was used in the same manner as in Example 2 to determine the in-plane arithmetic average roughness Ra, the maximum height roughness Rz, the kurtosis Rku, and the base 11 The maximum value (horizontal groove maximum value) and the minimum value (horizontal groove minimum value) of the groove width L of the grooves formed on the surface were measured. The results are shown in Table 3.

  Undercoat layer forming coating solution E was prepared in the same manner as in Example 2 except that the weight ratio of the surface-treated titanium oxide / copolymerized polyamide was changed to 2/1. The physical properties of this undercoat layer forming coating solution E were measured in the same manner as in Example 1. The results are shown in Table 2.

  The undercoat layer forming coating solution E was applied on the substrate 11 by dip coating so that the film thickness after drying was 2 μm, and dried to form an undercoat layer. When the surface of the undercoat layer was observed with a scanning electron microscope, almost no aggregates were observed.

A charge generation layer and a charge transport layer were formed on the undercoat layer in the same manner as in Example 10 to obtain a photoreceptor P12.
The produced photoreceptor is mounted on a cartridge (product name: Workio C262) manufactured by Panasonic Communication Co., Ltd. (as an integrated cartridge, having a two-component toner, a contact charging roller member, and a blade cleaning member), and an image is recorded. When formed, a good image could be obtained.

[Example 13]
Using an ironing tube made of A3003 aluminum alloy defined in JIS H4040 having an outer diameter of 30 mm, a length of 388 mm, and a thickness of 0.75 mm, a roughening treatment was performed in the same manner as in Example 11, and the surface of the substrate is shown in FIG. Such a curved and discontinuous, oblique groove was formed to obtain the substrate 12.
A part of this base 12 was left, and the left side was used in the same manner as in Example 2. In-plane arithmetic average roughness Ra, maximum height roughness Rz, kurtosis Rku, and base 12 The maximum value (horizontal groove maximum value) and the minimum value (horizontal groove minimum value) of the groove width L of the grooves formed on the surface were measured. The results are shown in Table 3.

A charge generation layer and a charge transport layer were formed on the substrate 12 in the same manner as in Example 12 to obtain a photoreceptor P13.
When the produced photoconductor was mounted on a cartridge of a copying machine (product name: Workio C262) manufactured by Panasonic Communication Co., Ltd. and an image was formed, a good image could be obtained.

[Comparative Example 1]
A6063 aluminum alloy specified in JIS H4040 with an outer diameter of 30 mm, length of 357 mm and thickness of 1.0 mm by cutting using a polycrystalline diamond tool so that the maximum surface roughness Rz is 0.6 μm A manufactured substrate 13 was produced.
A part of the substrate 13 was left, and the substrate 13 was used to measure the in-plane arithmetic average roughness Ra, the maximum height roughness Rz, and the kurtosis Rku of the substrate 13 in the same manner as in Example 1. The results are shown in Table 3.

A photosensitive layer was formed on the substrate 13 in the same manner as in Example 1 to obtain a photoreceptor P14.
Using the photoreceptor P14 thus obtained, an image was formed in the same manner as in Example 1, and image evaluation was performed visually. The results are shown in Table 3.

[Comparative Example 2]
Using a dispersion slurry obtained by mixing 50 parts of surface-treated titanium oxide and 120 parts of methanol and dispersing the mixture in a ball mill for 5 hours using an alumina ball (HD from Nikkato Co., Ltd.) having a diameter of about 5 mm. A coating liquid F for forming an undercoat layer was produced in the same manner as in Example 1 except that it was not dispersed using an apex mill.
The physical properties of the undercoat layer forming coating solution F were measured in the same manner as in Example 1. The results are shown in Table 2.

  The undercoat layer forming coating solution F was applied onto the substrate 1 by dip coating so that the film thickness after drying was 1.5 μm and dried to form an undercoat layer. When the surface of the undercoat layer was observed with a scanning electron microscope, aggregates were observed.

A charge generation layer and a charge transport layer were formed thereon in the same manner as in Example 1 to obtain a photoreceptor P15.
Using the photoreceptor P15 thus obtained, an image was formed in the same manner as in Example 1 and image evaluation was performed visually. The results are shown in Table 3.

[Comparative Example 3]
An A3003 aluminum alloy ironing tube defined by JIS H4040 with an outer diameter of 30 mm, length of 357 mm and thickness of 1.0 mm is used. The brush material is alumina with a diameter of 0.3 mm and a particle size of # 1000 (average particle size of 16 μm). A nylon material containing abrasive grains ("Sangrit" manufactured by Asahi Kasei Co., Ltd.) was used. The substrate 14 was obtained in the same manner as in Example 2 except that the minute condition was used, and a curved and discontinuous, oblique groove was formed.

  A part of this base 14 was left, and the left side was used in the same manner as in Example 2 to calculate the in-plane arithmetic average roughness Ra, the maximum height roughness Rz, the kurtosis Rku, and the base 14. The maximum value (horizontal groove maximum value) and the minimum value (horizontal groove minimum value) of the groove width L of the grooves formed on the surface were measured. The results are shown in Table 3.

A photosensitive layer was formed on the substrate 14 in the same manner as in Example 1 to obtain a photoreceptor P16.
Using the photoreceptor P16 thus obtained, an image was formed in the same manner as in Example 1, and image evaluation was performed visually. The results are shown in Table 3.

[Comparative Example 4]
A photosensitive layer was formed on the substrate 3 in the same manner as in Comparative Example 2 to obtain a photoreceptor P17.
Using the photoreceptor P17 thus obtained, an image was formed in the same manner as in Example 1, and image evaluation was performed visually. The results are shown in Table 3.

[Comparative Example 5]
Surface roughening was performed in the same manner as in Example 8 using a base made of A3003 aluminum alloy defined in JIS H4040 having an outer diameter of 30 mm, a length of 346 mm, and a thickness of 1.0 mm.
A part of this base 15 was left, and the left side was used in the same manner as in Example 2 to calculate the in-plane arithmetic average roughness Ra, maximum height roughness Rz, kurtosis Rku, and base 15 The maximum value (horizontal groove maximum value) and the minimum value (horizontal groove minimum value) of the groove width L of the grooves formed on the surface were measured. The results are shown in Table 3.

A photosensitive layer was formed on the substrate 15 in the same manner as in Example 10 to obtain a photoreceptor P18.
When the produced photoreceptor was mounted on a cartridge of a copying machine (product name: Workio DP1820) manufactured by Panasonic Communication Co., Ltd. and an image was formed, a good image could be obtained.

[Comparative Example 6]
Using a squeezing tube made of A3003 aluminum alloy defined by JIS H4040 having an outer diameter of 30 mm, a length of 388 mm, and a thickness of 0.75 mm, a roughening treatment was performed in the same manner as in Example 8 to obtain a substrate 16.
A part of this base 16 was left, and the left base 16 was used in the same manner as in Example 2 to calculate the in-plane arithmetic average roughness Ra, maximum height roughness Rz, kurtosis Rku, and The maximum value (horizontal groove maximum value) and the minimum value (horizontal groove minimum value) of the groove width L of the grooves formed on the surface were measured. The results are shown in Table 3.

A photosensitive layer was formed on the substrate 16 in the same manner as in Example 12 to obtain a photoreceptor P19.
When the produced photoreceptor P19 was mounted on a cartridge of a copying machine (product name: Workio C262) manufactured by Panasonic Communication Co., Ltd. and an image was formed, a good image could be obtained.

[Comparative Example 7]
Made of A6063 aluminum alloy specified in JIS H4040 with outer diameter φ30mm × length 357mm × thickness 1.0mm by cutting using polycrystalline diamond tool so that the maximum surface roughness Rz is 1.4μm A substrate 17 was prepared.
A part of the substrate 17 was left, and the substrate 17 was used to measure the in-plane arithmetic average roughness Ra, the maximum height roughness Rz, and the kurtosis Rku of the substrate 17 in the same manner as in Example 1. The results are shown in Table 3.

A photosensitive layer was formed on the substrate 17 in the same manner as in Example 1 to obtain a photoreceptor P20.
Using the photoreceptor P20 thus obtained, an image was formed in the same manner as in Example 1, and image evaluation was performed visually. The results are shown in Table 3.

[Comparative Example 8]
Using a squeezing tube made of A3003 aluminum alloy defined in JIS H4040 with an outer diameter of Φ30 mm, length of 346 mm, and thickness of 1.0 mm, the brush material has a diameter of 0.55 mm and a particle size of # 500 (average particle size of 34 μm). It is made of nylon material containing alumina abrasive grains ("Tinex A" manufactured by DuPont). The roughening conditions are as follows: substrate rotation speed 250rpm, brush rotation speed 750rpm, contact allowance 6mm, pulling speed 1.3mm / sec, sprinkling water volume 1L The substrate 18 was obtained in the same manner as in Example 2 except that the conditions were / minute, and curved and discontinuous, oblique grooves were formed on the substrate surface.

  A part of this base 18 was left, and with the set left in the same manner as in Example 2, the in-plane arithmetic average roughness Ra, the maximum height roughness Rz, the kurtosis Rku of the base 18 and the base 18 The maximum value (horizontal groove maximum value) and the minimum value (horizontal groove minimum value) of the groove width L of the grooves formed on the surface were measured. The results are shown in Table 3.

A photosensitive layer was formed on the substrate 18 in the same manner as in Example 10 to obtain a photoreceptor P21.
When the produced photoreceptor P21 was mounted on a cartridge of a copying machine (product name: Workio DP1820) manufactured by Panasonic Communication Co., Ltd. and an image was formed, a good image could be obtained.

  The present invention can be used in any industrial field, and in particular, can be suitably used for electrophotographic printers, facsimiles, copying machines, and the like.

It is a schematic diagram for demonstrating an example of the roughening method of the electroconductive base | substrate which concerns on this invention. It is a schematic diagram which shows an example of the shape of a groove | channel at the time of expand | deploying the surface of the electroconductive base | substrate which concerns on this invention to a plane. It is a schematic diagram which shows an example of the shape of a groove | channel at the time of expand | deploying the surface of the electroconductive base | substrate which concerns on this invention to a plane. It is a schematic diagram for demonstrating an example of the method of manufacturing the electroconductive base | substrate which concerns on this invention. It is a schematic diagram for demonstrating an example of the method of manufacturing the electroconductive base | substrate which concerns on this invention. It is a schematic diagram for demonstrating an example of the method of manufacturing the electroconductive base | substrate which concerns on this invention. It is a longitudinal cross-sectional view which represents typically the structure of the wet stirring ball mill which concerns on one Embodiment of this invention. It is an expanded longitudinal cross-sectional view which represents typically the mechanical seal used with the wet stirring ball mill which concerns on one Embodiment of this invention. It is a longitudinal cross-sectional view which represents typically another example of the wet stirring ball mill which concerns on one Embodiment of this invention. FIG. 10 is a transverse sectional view schematically showing a separator of the wet stirring ball mill shown in FIG. 9. 1 is a schematic diagram illustrating a main configuration of an embodiment of an image forming apparatus including an electrophotographic photosensitive member of the present invention. 3 is a powder X-ray diffraction spectrum pattern with respect to CuKα characteristic X-rays of oxytitanium phthalocyanine used as a charge generating material in the electrophotographic photoreceptors of Examples and Comparative Examples of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Conductive substrate 1A Conductive substrate shaft 2 Inner expansion gripping mechanism 3 Wheel-shaped brush 3A Wheel-shaped brush shaft 4 Cup-shaped brush 4A Cup-shaped brush shaft 5 Cleaning brush 14 Separator 15 Shaft 16 Jacket 17 Stator 19 Discharge path 21 Rotor 24 Pulley 25 Rotary joint 26 Raw material slurry supply port 27 Screen support 28 Screen 29 Product slurry outlet 31 Disk 32 Blade 35 Valve body 100 Sealing 101 Mating ring 102 Spring 103 Fitting groove 104 O-ring 105 Shaft 106 Separator 107 Spacer 108 rotor 109 stopper 110 screw 111 discharge path 112 hole 113 spacer 114 blade fitting groove 115 disk 116 blade 201 photoconductor 2 02 Charging device (charging roller)
DESCRIPTION OF SYMBOLS 203 Exposure device 204 Developing device 205 Transfer device 206 Cleaning device 207 Fixing device 241 Developing tank 242 Agitator 243 Supply roller 244 Developing roller 245 Restriction member 271 Upper fixing member (fixing roller)
272 Lower fixing member (fixing roller)
273 Heating device T Toner P Transfer material (paper, medium)

Claims (14)

An undercoat layer containing metal oxide particles and a binder resin on a conductive substrate having a maximum surface roughness Rz of 0.8 μm ≦ Rz ≦ 2 μm, and a photosensitive layer formed on the undercoat layer In an electrophotographic photoreceptor having
The volume average particle size of the undercoat layer measured by the dynamic light scattering method of the metal oxide particles in a liquid in which methanol and 1-propanol are mixed in a solvent mixed at a weight ratio of 7: 3 is 0. An electrophotographic photosensitive member characterized by having a particle size of 1 μm or less and a cumulative 90% particle size of 0.3 μm or less. 2. The electrophotographic photosensitive member according to claim 1, wherein the surface shape of the conductive substrate is formed by cutting. Fine grooves are formed on the surface of the conductive substrate,
2. The electrophotographic photosensitive member according to claim 1, wherein the shape of the groove is curved and discontinuous when the surface of the conductive substrate is developed on a plane. The electrophotographic photosensitive member according to claim 3, wherein the grooves formed on the surface of the conductive substrate have a lattice shape. Kurtosis Rku of the surface of the conductive substrate is 3.5 ≦ Rku ≦ 25, and
5. The electrophotographic photosensitive member according to claim 3, wherein a groove width L formed on the surface of the conductive substrate satisfies 0.5 μm ≦ L ≦ 6.0 μm. It is a manufacturing method of the electroconductive base | substrate with which the electrophotographic photoreceptor of any one of Claim 1 and Claims 3-5 is equipped,
A method for producing a conductive substrate, comprising: bringing a flexible material into contact with the surface of the conductive substrate and moving the flexible material relative to the surface of the conductive substrate. The method of manufacturing a conductive substrate according to claim 6, wherein a surface of the conductive substrate is cut in advance. The method of manufacturing a conductive substrate according to claim 6 or 7, wherein a surface of the conductive substrate is ironed in advance. The method for producing a conductive substrate according to any one of claims 6 to 8, wherein a surface of the conductive substrate is ground in advance. The method of manufacturing a conductive substrate according to any one of claims 6 to 9, wherein a surface of the conductive substrate is previously honed. The method for manufacturing a conductive substrate according to claim 6, wherein a brush is used as the flexible material. The method for manufacturing a conductive substrate according to claim 11, wherein the brush is made of a resin kneaded with abrasive grains. The electrophotographic photosensitive member according to any one of claims 1 to 5,
Charging means for charging the electrophotographic photosensitive member;
Image exposure means for performing image exposure on the charged electrophotographic photosensitive member to form an electrostatic latent image;
Developing means for developing the electrostatic latent image with toner;
An image forming apparatus comprising: a transfer unit that transfers the toner to a transfer target. The electrophotographic photosensitive member according to any one of claims 1 to 5,
Charging means for charging the electrophotographic photosensitive member, image exposing means for performing image exposure on the charged electrophotographic photosensitive member to form an electrostatic latent image, developing means for developing the electrostatic latent image with toner, the toner At least one of transfer means for transferring the toner to the transfer body, fixing means for fixing the toner transferred to the transfer body, and cleaning means for collecting the toner adhering to the electrophotographic photoreceptor. An electrophotographic cartridge.

Images