JP4282530B2 - Electrophotographic photoreceptor, method for producing electrophotographic photoreceptor, and image forming apparatus - Google Patents

Description

  The present invention relates to an electrophotographic photosensitive member, a method for producing an electrophotographic photosensitive member, and an image forming apparatus, and more particularly to an electrophotographic photosensitive member that generates less black spots even when electrophotographic printing is performed for a long time. The present invention relates to a method for producing an electrophotographic photosensitive member, and an image forming apparatus including such an electrophotographic photosensitive member.

Conventionally, an electrophotographic photosensitive member provided in an image forming apparatus is usually composed of a drum base tube having an anodized film provided on the surface of a conductive support and a photosensitive layer formed around the drum base tube. Yes.
More specifically, in order to prevent the occurrence of cracks in the anodic oxide film, in the electrophotographic photosensitive member in which the photoconductive layer is provided on the aluminum substrate having the anodic oxide film, the surface of the anodic oxide film has a concentration of 5 to 5. Admittance per unit area of the anodized film (as defined in JIS standards) by sealing with a 10 g / liter nickel acetate aqueous solution at a sealing processing temperature of 55 to 75 ° C. and a sealing processing time of about 5 minutes. In addition, an electrophotographic photoreceptor has been proposed in which a value obtained by measuring the degree of sealing using an aqueous potassium sulfate solution is set to a value in the range of 0.3 to 85 S / m ² (see, for example, Patent Document 1).
In addition, in order to solve the problem of generation of ground fog and minute black spots on the electrophotographic photosensitive member caused by the aluminum substrate having the anodized film, the surface of the anodized film is physically applied after the anodized film is formed on the aluminum substrate. A method of manufacturing an electrophotographic photosensitive member has been proposed in which contact rub cleaning is performed or ultrasonic cleaning is performed using a predetermined cleaning apparatus (see, for example, Patent Documents 2 and 3).
JP 7-295266 (Claims etc.) Patent 2582126 (Claims etc.) Patent 3001666 (Claims etc.)

However, in the electrophotographic photoreceptor disclosed in Patent Document 1, when performing the sealing process, a specific chemical must be used and strictly performed under conditions of a predetermined temperature and a predetermined time. There was a problem that was extremely complicated.
In addition, in the method for producing an electrophotographic photoreceptor disclosed in Patent Documents 2 and 3, physical sealing is performed after sealing, or ultrasonic cleaning is performed using a predetermined cleaning device. In addition, while a specific manufacturing apparatus has to be prepared, there has been a problem that the characteristics vary greatly depending on the manufacturing conditions.

Accordingly, the inventors of the present invention have made extensive studies on the above-described problems, and as a result, unlike the conventional knowledge, positively generating a predetermined crack in the anodic oxide film improves the adhesion to the photoreceptor. In addition, the inventors have found that local charge injection can be prevented, and as a result, generation of black spots can be easily prevented, and the present invention has been completed.
That is, an object of the present invention is to provide an electrophotographic photosensitive member that can effectively prevent the occurrence of black spots and the like and an image forming apparatus including such an electrophotographic photosensitive member even with a simple technique.

According to the present invention, a drum base tube anodized film on the surface of the conductive support is provided, a photosensitive layer formed around them, a configured electrophotographic photoreceptor from anodized film with the thickness of a value within the range of 4～12Myuemu, the surface of the anodized film, fine cracks depth is a value within the range of 0.8~3μm is, a 254 mm × 10 mm on the photosensitive layer surface Provided is an electrophotographic photosensitive member characterized in that a photosensitive layer is formed on an anodized film formed within a range of 3 to 20 per area and having microcracks. Thus, the above-described problems can be solved.

  In constructing the electrophotographic photosensitive member of the present invention, it is preferable to set the ten-point average surface roughness (Rz) of the anodic oxide film to a value within the range of 0.1 to 0.3 μm.

Further, in constituting the electrophotographic photosensitive member of the present invention, it is preferable that the degree of sealing of the anodized film (Y ₅ , converted to a film thickness of 5 μm) measured in accordance with JIS H8863 is 80 μS or less.

  In constituting the electrophotographic photosensitive member of the present invention, the photosensitive layer is preferably a single layer type.

  In constituting the electrophotographic photosensitive member of the present invention, it is preferable that the photosensitive layer is a laminated type, and an undercoat layer is provided between the drum base tube and the photosensitive layer.

  In constituting the electrophotographic photosensitive member of the present invention, the thickness of the photosensitive layer is preferably set to a value within the range of 1 to 30 μm.

  The electrophotographic photoreceptor of the present invention is preferably a dry developing electrophotographic photoreceptor or a wet developing electrophotographic photoreceptor.

Another aspect of the present invention is a method for producing an electrophotographic photoreceptor comprising a drum base tube having an anodized film provided on the surface of a conductive support, and a photosensitive layer formed around the drum base tube. In the case where the temperature of the step of forming the anodic oxide film so as to have a thickness in the range of 4 to 12 μm and the sealing treatment of the anodic oxide film is less than 60 to 80 ° C. The sealing treatment time is set to a value within the range of 8 to 60 minutes, and when the sealing treatment temperature is 80 to 95 ° C., the sealing treatment time is set to a value within the range of 1 to 25 minutes. In this way, a microcrack having a depth in the range of 0.8 to 3 μm is formed on the surface of the anodized film within a range of 3 to 20 per area of 254 mm × 10 mm on the surface of the photosensitive layer. And a step of forming a single-layer type or a multi-layer type photosensitive layer. It is a manufacturing method of a child photoreceptor.

  Another aspect of the present invention is an image forming apparatus including any of the electrophotographic photosensitive members described above.

  According to the electrophotographic photoreceptor of the present invention, microcracks are forcibly formed on the surface of the anodic oxide film, thereby improving the adhesion with the photoreceptor and preventing local charge injection. As a result, it is possible to provide an electrophotographic photosensitive member that can effectively prevent the occurrence of black spots.

  Further, according to the electrophotographic photosensitive member of the present invention, by setting the depth of the microcracks to a value within a predetermined range, the predetermined heat resistance and dielectric breakdown voltage in the anodized film can be maintained, and the potential in the photosensitive member can be maintained. While effectively preventing changes, it is possible to effectively prevent the occurrence of black spots.

  In addition, according to the electrophotographic photosensitive member of the present invention, by making the thickness of the anodic oxide film within a predetermined range, it is possible to more effectively prevent black spots and the like while effectively preventing potential changes in the photosensitive member. Can be prevented.

  In addition, according to the electrophotographic photosensitive member of the present invention, by setting the ten-point average surface roughness (Rz) of the anodic oxide film to a value within a predetermined range, black spots are generated while maintaining the smoothness of the photosensitive member. Etc. can be effectively prevented.

Further, according to the electrophotographic photoreceptor of the present invention, the predetermined heat resistance and dielectric breakdown voltage in the anodic oxide film can be maintained by setting the degree of sealing (Y ₅ ) of the anodic oxide film within a predetermined range. However, the sensitivity of the photoreceptor can be improved.

  Further, according to the electrophotographic photosensitive member of the present invention, since the photosensitive layer is a single layer type, it is possible to effectively prevent the generation of black spots and the like while having a simple structure. Further, the current leakage from the photosensitive layer can be adjusted to a value within a desired range only by appropriately changing the amount of the charge generating agent added.

  Further, according to the electrophotographic photosensitive member of the present invention, the photosensitive layer is a laminated type, and the undercoat layer is provided between the drum base tube and the photosensitive layer, so that the black spot of the black spot is simplified. Generation | occurrence | production etc. can be prevented effectively. Also, current leakage from the charge generation layer in the photosensitive layer can be adjusted to a value within a desired range by providing an undercoat layer.

  In addition, according to the electrophotographic photoreceptor of the present invention, predetermined mechanical strength and charging characteristics in the photosensitive layer can be stably obtained by setting the thickness of the photosensitive layer within a predetermined range.

  In addition, according to the electrophotographic photosensitive member of the present invention, microcracks are positively formed on the surface of the anodized film in both the dry developing electrophotographic photosensitive member and the wet developing electrophotographic photosensitive member. As a result, the adhesion to the photoreceptor is improved and the durability and solvent resistance are excellent, so that the generation of black spots and the like can be effectively prevented.

  In addition, according to the method for producing an electrophotographic photosensitive member of the present invention, after forming the anodic oxide film, a microcrack is stably formed on the surface of the anodic oxide film by performing sealing treatment at a predetermined temperature and for a predetermined time. Can be formed.

  Further, according to another aspect of the present invention, according to the image forming apparatus including any one of the above-described electrophotographic photosensitive members, the electrophotographic photosensitive member can effectively prevent the generation of black spots even with a simple technique. Can be provided.

  Embodiments relating to the electrophotographic photosensitive member, the method for producing the electrophotographic photosensitive member, and the image forming apparatus of the present invention will be specifically described below.

[First embodiment]
In the first embodiment, as illustrated in FIG. 1, a drum base tube 13 a in which an anodized film 12 is provided on the surface of a conductive support 13, and as illustrated in FIG. 2 (or FIG. 3), An electrophotographic photoreceptor 10 (20) composed of a photosensitive layer 11 (11c, 11d) formed therearound, and the thickness of the anodized film is set to a value within the range of 4 to 12 μm. On the surface of the anodic oxide film 12, fine cracks 12a having a depth within a range of 0.8 to 3 μm are formed within a range of 3 to 20 per 254 mm × 10 mm area on the surface of the photosensitive layer. The electrophotographic photosensitive member 10 (20) is characterized in that a photosensitive layer is formed on an anodic oxide film having a microcrack .

1. As shown in FIG. 2 or FIG. 3, the drum base tube 13a functions as a base material for forming the single-layer type photosensitive layer 11 or the stacked type photosensitive layers 11c and 11d. A cylindrical shape is preferred because it is rotated. In addition, because it has a predetermined length, thickness, and outer dimensions, it is made of aluminum, A5000 series or A6000 series aluminum alloy, etc. as a raw material, cylindrically processed by mandrel method etc., and further formed by drawing preferable.
However, when aluminum or the like is used as the raw material for the drum base tube, oxidation on the surface of the drum base tube is accelerated, and the charging potential of the electrophotographic photosensitive member may change. Therefore, the surface of the drum base tube 13a is anodized to forcibly form the anodic oxide film 12. In the first embodiment, the adhesion between the drum tube 13a and the photosensitive layer 11 (11c, 11d) is improved, and black spots are generated during long-term printing by the electrophotographic photosensitive member 10 (20). In order to prevent this, a predetermined crack 12 a is forcibly formed in the anodic oxide film 12.

Here, it is preferable to set the length of the microcrack in the anodic oxide film to a value within the range of 0.1 mm to 50 mm.
This is because if the length of such microcracks is less than 0.1 mm, the adhesion between the drum tube and the electrophotographic photosensitive member may be reduced, and black spots may easily occur. is there. On the other hand, when the length of the microcracks exceeds 50 mm, the dielectric breakdown strength is remarkably lowered, and the charged potential in the electrophotographic photosensitive member becomes unstable, and it may be difficult to control the desired charged potential. Because.
Therefore, the length of the microcrack in the anodic oxide film is more preferably set to a value within the range of 0.5 mm to 40 mm, and further preferably set to a value within the range of 5 mm to 30 mm.

Moreover, it is preferable to make the width | variety of the micro crack in an anodic oxide film into the value within the range of 0.5 micrometer-20 micrometers.
The reason for this is that when the width of the microcracks is less than 0.5 μm, the adhesion between the drum tube and the electrophotographic photosensitive member is lowered, and black spots are likely to occur. . On the other hand, when the width of the microcrack exceeds 20 μm, the dielectric breakdown strength is remarkably lowered, and the charged potential in the electrophotographic photosensitive member becomes unstable, and it may be difficult to control the desired charged potential. It is.
Therefore, the width of the microcrack in the anodized film is more preferably set to a value within the range of 0.8 μm to 15 μm, and further preferably set to a value within the range of 1 μm to 10 μm.

Further, the depth of the microcrack is set to a value within a range of 0.8 μm to 3 μm.
The reason for this is that when the depth of such microcracks is less than 0.8 μm , the adhesion between the drum tube and the electrophotographic photosensitive member is lowered, and black spots are likely to occur. is there. On the other hand, when the depth of the microcracks exceeds 3 μm , the dielectric breakdown strength is remarkably lowered, and the charged potential in the electrophotographic photosensitive member becomes unstable, and it may be difficult to control the desired charged potential. Because.

Further, characterized in that the thickness of the anodic oxide film a value within the range of 4Myuemu～12myuemu.
The reason for this is that if the thickness of the anodic oxide film is less than 4 μm, the anti-oxidation effect on the surface of the drum base tube is not exhibited, and the charged potential in the electrophotographic photosensitive member is likely to change. It is. On the other hand, even if the thickness of the anodic oxide film exceeds 12 μm, residual memory or the like is liable to occur. For this reason, the charged potential in the electrophotographic photosensitive member becomes unstable and difficult to control to a desired value. This is because there may be cases.
Therefore, the thickness of the anodic oxide film is more preferably set to a value within the range of 5 μm to 10 μm.

Further, it is preferable that the ten-point average surface roughness (Rz) of the anodic oxide film is set to a value within the range of 0.1 μm to 0.3 μm.
The reason for this is that when the ten-point average surface roughness of such an anodic oxide film is less than 0.1 μm, the adhesion between the drum tube and the electrophotographic photosensitive member is lowered, and black spots are likely to occur. This is because there are cases. On the other hand, if the ten-point average surface roughness of the anodized film exceeds 0.3 μm, the smoothness of the electrophotographic photosensitive member is lowered, and the charging potential of the electrophotographic photosensitive member becomes unstable, and is controlled to a desired value. This is because it may be difficult to do.
Therefore, it is more preferable to set the ten-point average surface roughness of the anodized film to a value within the range of 0.15 μm to 0.25 μm.
The ten-point average surface roughness (Rz) of the anodic oxide film can be measured according to JIS B 0601.

Moreover, it is preferable that the degree of sealing (Y ₅ ) of the anodic oxide film is 80 μS or less.
This is because when the degree of sealing of the anodic oxide film exceeds 80 μS, the porous portion increases, and it may be difficult to remove foreign matter or the like adhering to the surface even after cleaning. is there.
However, if the degree of sealing of the anodic oxide film is excessively small, the resistance value of the anodic oxide film is too large and the sensitivity characteristic of the photoreceptor may be deteriorated.
Therefore, the sealing degree of the anodic oxide film is more preferably set to a value within the range of 10 μS to 75 μS, and further preferably set to a value within the range of 20 μS to 70 μS.
The sealing degree (Y ₅ ) of the anodic oxide film can be calculated by converting the sealing degree of the anodic oxide film measured according to JIS H8863 to a film thickness of 5 μm.

2. Photosensitive Layer As shown in FIGS. 2A to 2C, the photosensitive layer is a single-layer type photosensitive layer 10 containing a binder resin, a charge generator, a hole transport agent, and an electron transport agent in a single layer 11. 10 ′, 10 ″, and as shown in FIGS. 3A to 3B, the binder resin, the charge generating agent, the hole transporting agent, and the electron transporting agent are divided into a plurality of layers 11c and 11d. There are laminated photosensitive layers 20 and 20 ', but the electrophotographic photoreceptor of the present invention is applicable to any of them.
However, it is preferably applied to a single-layer type from the viewpoints that it can be used for both positive and negative charge types, that the structure is simple and easy to manufacture, that there are few interfaces between layers, and optical characteristics can be improved. .

  As shown in FIG. 2A, the single-layer type photosensitive layer is provided with the photosensitive layer 11 directly via the anodic oxide film 12 including the microcracks 12a formed on the drum base tube 13. May be configured. Further, as shown in FIG. 2B, an undercoat layer 11a is further provided on the anodic oxide film 12 including the microcracks 12a formed on the drum base tube 13, and the photosensitive layer 11 is interposed therebetween. May be provided. Further, as shown in FIG. 2 (c), the photosensitive layer 11 is directly provided via the anodic oxide film 12 including the microcracks 12a formed on the drum base tube 13, and a protective layer is formed on the outer surface. 11b may be provided separately.

On the other hand, when the photosensitive layer is a laminated type, as shown in FIGS. 3A to 3B, between the anodized film 12 in the drum base tube 13 and the laminated photosensitive layer 11c (or 11d). It is preferable to provide the undercoat layer 11a.
The reason for this is that by forcibly forming the microcracks 12a in the anodic oxide film 12, the electrical withstand voltage is reduced to some extent, and charges may easily leak from the charge generation layer 11c and the like. This is because the charge leakage value can be adjusted by the pulling layer 11a.
Therefore, polyamide resin, polyvinyl alcohol resin, polyurethane resin, polyacryl resin, polyester resin, epoxy resin, phenol resin, and the like can be used as the constituent material of the undercoat layer. And what disperse | distributed predetermined amount of electroconductive particle to these resin can also be used conveniently.
Further, the undercoat layer may be a single layer or a plurality of structures, and the film thickness is usually a value in the range of 0.1 to 20 μm, more preferably in the range of 0.2 to 10 μm. It is a value in.
In the case of a laminated photosensitive layer, as shown in FIG. 3A, an anodic oxide film 12 including a microcrack 12a and an undercoat layer 11a are provided on a conductive substrate 13, and a charge is further formed thereon. The charge generation layer 11c and the charge transport layer 11d containing the generator may be sequentially formed. Alternatively, the positional relationship between the charge generation layer 11c and the charge transport layer 11d is reversed, and the anodic oxide film 12 and the undercoat layer 11a including the microcracks 12a are formed on the conductive substrate 13 as shown in FIG. Further, the charge transport layer 11d and the charge generation layer 11c may be sequentially formed thereon.

Even if the photosensitive layer is a single layer type or a laminated type, the thickness of the photosensitive layer is preferably set to a value in the range of 1 to 30 μm.
This is because, when the thickness of the photosensitive layer is less than 1 μm, the mechanical strength of the photosensitive layer may be lowered or the smoothness of the photosensitive layer may be lowered. On the other hand, if the thickness of the photosensitive layer exceeds 30 μm, it may be difficult to form a uniform thickness, or the sensitivity may decrease.
Therefore, the thickness of the photosensitive layer is more preferably set to a value within the range of 5 to 20 μm.

3. Others In order to smoothly rotate the electrophotographic photosensitive member, it is preferable to provide a flange at the end of the drum base tube of the electrophotographic photosensitive member. That is, it can be rotated in synchronization with the electrophotographic photosensitive member or vibrated through a gear provided on the flange.
Furthermore, a ground plate is provided between the flange and the drum base tube (not shown), and a protrusion for contacting the inner surface of the drum base tube and a through hole are inserted around the ground plate. It is preferable that a contact piece for contacting the shaft pin is provided.
With such a ground plate, when the ground plate is attached to the flange and the flange is press-fitted into the drum base tube, the protrusions damage the inner surface of the drum base tube, and the contact piece presses against the shaft pin to cause the drum base This is because the pipe and the shaft pin can be reliably connected.

[Second Embodiment]
In the second embodiment, the step of forming the anodic oxide film so as to have a value in the range of 4 to 12 μm, and the temperature when sealing the anodic oxide film is less than 60 to 80 ° C. In this case, the sealing treatment time is set to a value within the range of 8 to 60 minutes, and when the sealing treatment temperature is 80 to 95 ° C., the sealing treatment time is within the range of 1 to 25 minutes. By setting the value, fine cracks each having a depth in the range of 0.8 to 3 μm are formed on the surface of the anodized film within the range of 3 to 20 per area of 254 mm × 10 mm on the photosensitive layer surface. An electrophotographic photosensitive member manufacturing method comprising: a step of forming; and a step of forming a single layer type or a multilayer type photosensitive layer.

1. Step of forming anodized film When a metal such as aluminum is used as a constituent material of the drum base tube, in order to prevent the oxidation from proceeding and the charged potential on the photoreceptor from changing, a generally known method is used. An anodic oxide film is formed.
Therefore, it is preferable that the drum base tube is washed with an organic solvent or a surfactant or degreased before being anodized, and further etched.
The anodized film can be formed, for example, by anodizing in an acidic bath such as sulfuric acid, oxalic acid, chromic acid, boric acid, etc., but it is particularly preferable to anodize in sulfuric acid. . When anodizing is performed in sulfuric acid, for example, the sulfuric acid concentration is in the range of 100 to 200 g / liter, the aluminum ion concentration is in the range of 1 to 10 g / liter, and the liquid temperature is in the range of 15 to 40 ° C. The electrolysis voltage is preferably in the range of 10 to 40V.

Here, as shown in FIG. 4, the thickness of the anodized film varies depending on the conditions of the anodizing treatment. Between the thickness of the anodized film and the occurrence temperature of microcracks (measured temperature by the AE apparatus). Are found to have a predetermined correlation.
Therefore, when the thickness of the anodized film is about 6 to 8 μm or less, it is heated to around 160 to 180 ° C., or the sealing treatment temperature to be described later is controlled within such a range, so that microcracks can be stably formed. Can be generated.
Further, if the thickness of the anodized film is about 8 to 10 μm or less, it can be heated to around 145 to 160 ° C., or the sealing treatment temperature described later can be controlled within such a range to stably form microcracks. Can be generated.
Further, if the thickness of the anodized film is about 10 to 12 μm or less, it can be stably heated to 135 to 145 ° C., or the sealing treatment temperature described later can be controlled within such a range to stably form microcracks. Can be generated.
Furthermore, if the thickness of the anodized film is set to about 12 to 21 μm, heating to 125 to 135 ° C. or controlling the sealing temperature described later to such a range will stably generate microcracks. Can be made.
Therefore, even if the temperature varies somewhat, it can be said that it is preferable to set the thickness of the anodized film to a value of 12 μm or less because microcracks can be stably generated.

In addition, as shown in FIG. 5, when anodizing is performed in sulfuric acid, there is a predetermined correlation between the value of the electrolysis voltage and the temperature at which microcracks are generated (measured temperature by an AE apparatus). Is found.
Therefore, when the value of the electrolysis voltage is 10 V or less, microcracks can be stably generated by heating to around 120 ° C. or controlling the sealing treatment temperature described later to such a temperature.
In addition, when the value of the electrolysis voltage is 12 V or less, minute cracks are stably generated by heating to around 130 ° C. after the anodizing treatment or by controlling the sealing treatment temperature described later to such a temperature. be able to.
In addition, when the value of the electrolytic voltage is 14 V or less, minute cracks are stably generated by heating to around 140 ° C. after anodizing or by controlling the sealing treatment temperature described later to such a temperature. be able to.
In addition, when the value of the electrolysis voltage is 17 V or less, minute cracks are stably generated by heating to around 150 ° C. after the anodizing treatment or by controlling the sealing treatment temperature described later to such a temperature. be able to.
Further, when the value of the electrolysis voltage is 20 V or less, minute cracks are stably generated by heating to around 160 ° C. after the anodizing treatment or by controlling the sealing treatment temperature described later to such a temperature. be able to.
Furthermore, when the value of the electrolysis voltage exceeds 20V, heating to a temperature of 160 ° C. or higher after the anodizing treatment, or controlling the sealing treatment temperature described later to such a temperature makes it possible to stably form microcracks. Can be generated.
Therefore, even if the temperature varies somewhat, it is possible to stably generate microcracks. Therefore, it can be said that the value of the electrolysis voltage when the anodizing treatment is performed in sulfuric acid is preferably 10 V or more.

In addition, as shown in FIG. 6, when anodizing is performed in sulfuric acid, there is a predetermined correlation between the value of electrolysis temperature and the temperature at which microcracks are generated (temperature measured by an AE apparatus). Is found.
Therefore, when the electrolysis temperature is 10 ° C. or less, the microcracks can be stably stabilized by heating to a value exceeding 140 ° C. after the anodizing treatment or by controlling the sealing treatment temperature described later to such a temperature. Can be generated.
In addition, when the electrolysis temperature is 20 ° C. or lower, the microcracks can be stably formed by heating to around 135 ° C. to 140 ° C. after the anodizing treatment or by controlling the sealing treatment temperature described later to such a temperature. Can be generated.
In addition, when the electrolysis temperature is 30 ° C. or lower, the microcracks can be stably stabilized by heating up to 120 to 135 ° C. after the anodizing treatment or by controlling the sealing treatment temperature described later to such a temperature. Can be generated.
Therefore, even if the temperature varies somewhat, it is possible to stably generate microcracks. Therefore, it can be said that it is preferable to set the value of the electrolysis temperature when anodizing in sulfuric acid to 20 ° C. or less.

2. Next, it is preferable to perform a sealing treatment on the anodized film. And while performing this sealing process, it is preferable to form a microcrack compulsorily with respect to an anodized film simultaneously or after a sealing process.
In addition, when performing the sealing treatment, it is preferable to use pure boiling water, but it is more preferable to immerse it in an aqueous solution containing nickel acetate as a main component. In that case, it is preferable to set the concentration of nickel acetate to a value within the range of 5 to 10 g / liter and the pH within the range of 5 to 6.
And when the temperature at the time of sealing an anodized film is less than 60-80 degreeC, the sealing processing time shall be a value within the range of 8-60 minutes, and the temperature at the time of sealing processing is 80-. In the case of 95 ° C., the sealing treatment time is preferably set to a value within the range of 1 to 25 minutes.
The reason for this is that micro-cracks can be stably formed on the surface of the anodized film by correlating with such sealing processing temperature and sealing processing time.

Here, as shown in FIG. 7, there is a predetermined correlation between the sealing process time, that is, the sealing time and the generation temperature of microcracks (measured temperature by the AE apparatus). I can find it.
Therefore, when the value of the sealing time is 20 minutes or less, it is possible to stably generate microcracks by controlling the sealing treatment temperature to 160 ° C. or higher.
Moreover, when the value of sealing time is 30 minutes or less, a microcrack can be stably generated by controlling the sealing treatment temperature to 150 ° C. or higher.
Moreover, when the value of sealing time is 40 minutes or less, a microcrack can be stably generated by controlling the sealing treatment temperature to 140 ° C. or higher.
Moreover, when the value of sealing time exceeds 40 minutes, a micro crack can be generated stably by controlling sealing processing temperature to the vicinity of 130-140 degreeC.
That is, it can be made at a relatively low temperature, and even if the temperature varies somewhat, since it can stably generate microcracks, as described above, depending on the temperature at the time of sealing the anodic oxide film, It is preferable to change the sealing treatment time.

Further, when sealing the anodic oxide film, as shown in FIGS. 8 and 9, the sealing temperature and the sealing time affect the sealing degree (Y ₅ ) for the anodic oxide film, respectively. Has also been found. In FIG. 8, the horizontal axis indicates the sealing temperature (° C.), and the vertical axis indicates the sealing degree (Y ₅ ). In FIG. 9, the horizontal axis indicates the sealing time (minutes), and the vertical axis indicates the sealing degree (Y ₅ ).
Therefore, by appropriately adjusting the sealing temperature and the sealing time, the sealing degree (Y ₅ ) of the anodic oxide film is set to a value of 80 μS or less, more preferably a value within the range of 20 to 70 μS. The balance between the removability of foreign matters adhering to the photosensitive member and the sensitivity characteristic of the photosensitive member becomes better.

3. Step of forming photosensitive layer As described above, the photosensitive layer is formed on the conductive substrate 13 as the single-layer type photoreceptors 10, 10 ′, 10 ″ as shown in FIGS. The thing which provided the photosensitive layer 11 which consists of a single layer on the anodic oxide film 12 containing the provided microcrack 12a can be illustrated.
That is, the photosensitive layer includes a single layer type and a laminated type. When a single layer type photosensitive layer is formed, for example, in an ultrasonic disperser, a charge generator and a hole transport agent are used. And an electron transporting agent, a binder resin, a leveling agent, and a solvent are mixed and dispersed to create a coating solution, which is then applied onto the anodized aluminum base tube by a dip coating method. It is preferable to form.
On the other hand, when forming a laminated photosensitive layer, as shown in FIG. 3A, vapor deposition or deposition is performed on the conductive substrate 13 provided with the anodic oxide film 12 including the microcracks 12a and the undercoat layer 11a. A charge generation layer 11c containing a charge generation agent is formed by means such as coating, and then a coating liquid containing a hole transport agent and a binder resin is applied onto the charge generation layer 11c and dried to charge transport. It can be created by forming the layer 11d.
As described above, when the stacked photosensitive layer is formed by reversing the positional relationship between the charge generation layer 11c and the charge transport layer 11d, the microcracks 12a are formed as shown in FIG. A charge transport layer 11d is formed on the conductive base 13 provided with the anodic oxide film 12 and the undercoat layer 11a by means such as vapor deposition or coating, and similarly, charge is generated thereon by means such as vapor deposition or coating. The layer 11c may be formed.

[Third embodiment]
The third embodiment relates to an image forming apparatus provided with the electrophotographic photosensitive member shown in the first embodiment.

1. Basic Configuration FIG. 10 shows a basic configuration of an image forming apparatus 50 according to the present invention. The image forming apparatus 50 includes a drum-type photoconductor 10. A primary charger 14 a, an exposure device 14 b, a developer 14 c, and the like are arranged around the photoconductor 10 along a rotation direction indicated by an arrow A. The transfer charger 14d, the separation charger 14e, the cleaning device 18, and the static eliminator 23 are sequentially arranged.
Further, the recording material P is transported in order from the upstream side along the transport direction indicated by the arrow B by the feed rollers 19a and 19b and the transport belt 21, and the toner is fixed on the way to form an image. A fixing roller 22a and a pressure roller 22b are provided.
The photoconductor 10 includes the predetermined anodic oxide film 12 described in the first embodiment on the support base 13. Accordingly, it is possible to include an anodic oxide film having microcracks and to exhibit excellent electrical characteristics and image characteristics over a long period of time.

(2) Operation Next, the basic operation of the image forming apparatus 50 will be described with reference to FIG.
First, the photosensitive member 10 of the image forming apparatus 50 is rotated at a predetermined process speed (circumferential speed) in a direction indicated by an arrow A by a driving unit (not shown), and the surface thereof is predetermined by a primary charger 14a. Charge to the polarity and potential. For example, in the case of a system in which a conductive elastic roller is brought into contact with the surface of the photosensitive member, it is preferable to apply a direct current voltage of about 1 to 2 KV and positively charge to 50 to 2000V.
Next, the surface of the photoreceptor 10 is exposed by irradiating light through a reflection mirror or the like while being light-modulated according to image information by an exposure device 14b such as a laser or LED. By this exposure, an electrostatic latent image is formed on the surface of the photoreceptor 10.

Next, based on the electrostatic latent image, the developer (toner) is developed by the developing device 14c. That is, toner is stored in the developing device 14c, and by applying a predetermined developing bias to the developing sleeve provided, the toner adheres corresponding to the electrostatic latent image on the photoreceptor 10, and the toner An image is formed.
Next, the toner image formed on the photoreceptor 10 is transferred to the recording material P. The recording material P is fed from a paper feed cassette (not shown) by paper feed rollers 19a and 19b, and then adjusted so that the timing is synchronized with the toner image on the photoconductor 10. And a transfer charger 14d. The toner image on the photoconductor 10 can be reliably transferred onto the recording material P by applying a predetermined transfer bias to the transfer charger 14d.

Next, the recording material P onto which the toner image has been transferred is separated from the surface of the photoreceptor 10 by the separation charger 14e and conveyed to the fixing device by the conveyance belt 21. Here, the toner image is fixed on the surface by heat treatment and pressure treatment by the fixing roller 22a and the pressure roller 22b, and then discharged to the outside of the image forming apparatus 50 by a discharge roller (not shown).
On the other hand, the photoconductor 10 after the transfer of the toner image continues to rotate, and residual toner (adhered matter) that has not been transferred to the recording material P at the time of transfer is removed from the surface of the photoconductive layer 11 by the cleaning device 18 and photosensitized. The body 10 is to be used for the next image formation.
As described above, since the photoconductor 10 includes the predetermined anodic oxide film 12 described in the first embodiment on the support base 13, it exhibits excellent electrical characteristics and image characteristics over a long period of time. be able to.

[Example 1]
(1) Preparation of electrophotographic photosensitive member for dry development (single layer type) (1) -1 Preparation of an aluminum base tube provided with an anodized film An aluminum base tube made of an aluminum alloy (JIS6063 material) having a diameter of 30 mm is degreased. Using Top Alclean 101 (Okuno Pharmaceutical Co., Ltd.), which is an agent, degreasing was performed under a temperature condition of 60 ° C., followed by washing with water to remove the degreasing agent. Next, degreasing and cleaning were sufficiently performed using a nitric acid solution having a concentration of 15%, and further cleaning with pure water was performed. Next, this aluminum base tube was subjected to anodizing treatment for 20 minutes under an electrolytic voltage condition of nitric acid concentration of 180 g / liter, temperature of 20 ° C., and 18 V to form an anodized film having a thickness of 6 μm.
Next, a nickel acetate solution having a concentration of 6 g / liter was used, and sealing was performed at a liquid temperature of 55 ° C. for 10 minutes. Thereafter, the aluminum base tube was heated at 140 ° C. for 60 minutes to forcibly form microcracks, thereby obtaining an aluminum base tube for a photoreceptor.
At this time, the number of microcracks per 10 mm in the drum circumferential direction formed on the anodized film on the surface of the aluminum base tube was measured from an optical microscope photograph, and the depth was measured with an interference microscope WYKO NT 1100 (manufactured by Veeco). Was actually measured. The obtained results are shown in Table 1.

(1) -2 Formation of photosensitive layer As a charge generating agent, 4 parts by weight of X-type metal-free phthalocyanine (CGM-A) represented by the following formula (1) and a hole transporting agent are used. 40 parts by weight of a bisstilbene derivative (HTM-A) represented by the formula, 50 parts by weight of a naphthoquinone derivative (ETM-A) represented by the following formula (3) as an electron transporting agent, and a binder resin As 100 parts by weight of the polycarbonate resin (Resin-A) represented by the following formula (4) and 0.1 parts by weight of KF-96-50CS (manufactured by Shin-Etsu Chemical Co., Ltd.) which is a dimethyl silicone oil as a leveling agent. And 750 parts by weight of tetrahydrofuran as a solvent were housed in a container, and then mixed and dispersed for 1 hour with an ultrasonic disperser to prepare a coating solution.
The obtained coating solution was applied by dip coating on an aluminum base tube provided with an anodized film having a diameter of 30 mm and a length of 254 mm. Thereafter, the film was dried with hot air at 130 ° C. for 30 minutes to obtain a dry developing electrophotographic photosensitive member (single layer type) having a photosensitive layer thickness of 18 μm.

(2) Evaluation The obtained electrophotographic photosensitive member for dry development (single layer type) is mounted on a copying machine Creation 7340 (manufactured by Kyocera Mita Co., Ltd.), and H / H environmental conditions (35 ° C., 85% RH) Then, 10,000 sheets of A4 paper were continuously printed, and the occurrence of black spots was evaluated according to the following criteria.
A: Generation of black spots is not observed at all in the unit area (20 cm ² ).
○: The number of black spots is 2 or less per unit area (20 cm ² ).
Δ: The number of black spots is 3 to 10 per unit area (20 cm ² ).
X: The number of black spots is 11 or more per unit area (20 cm ² ).

[Example 2]
(1) Preparation of electrophotographic photosensitive member (stacked type) for dry development (1) -1 Preparation of an aluminum base tube provided with an anodized film A nickel acetate solution having a concentration of 6 g / liter was used, and the liquid temperature was 70 ° C., 20 In the same manner as in Example 1, except that the sealing treatment was performed under the conditions of minutes, the sealing treatment was performed, and heating was performed under the conditions of 140 ° C. for 60 minutes to form microcracks. A blank tube was used.

(1) -2 Formation of Photosensitive Layer In Example 2, instead of the single-layer type electrophotographic photosensitive member for dry development in Example 1, a laminate type electrophotographic photosensitive member for dry development was prepared as the photosensitive layer. And evaluated.
That is, 20 parts by weight of rutile-type titanium oxide grafted with polyamide (rutile-type titanium oxide: polyamide weight ratio = 17: 3) and 17 of solvent-soluble polyamide resin Toresin MF-30 (manufactured by Teikoku Chemical Industry Co., Ltd.) Part by weight and 260 parts by weight of methanol were placed in a container, and then dispersed and mixed using an ultrasonic disperser to prepare an undercoat layer coating solution. This undercoat layer coating solution was applied by dipping onto an aluminum substrate, and then heated and dried at 100 ° C. for 15 minutes to form an undercoat layer having a thickness of 2 μm.

Next, 1 part by weight of Y-type titanyl phthalocyanine represented by the following formula (5), 1 part by weight of polyvinyl butyral BM-1 (manufactured by Sekisui Chemical Co., Ltd.), and 50 parts by weight of diacetone alcohol, A charge generation layer coating solution was prepared by dispersing and mixing using a ball mill. The charge generation layer coating solution was applied by dipping and dried by heating at 70 ° C. for 10 minutes to form a charge generation layer having a thickness of 0.3 μm.
Next, 60 parts by weight of a bis-stilbene compound (HTM-A) represented by the formula (2) used in Example 1 as a charge transport agent and a polycarbonate resin represented by the formula (4) as a binder resin ( 100 parts by weight of Resin-A), 0.1 part by weight of dimethylethylene oil KF-96-50CS (manufactured by Shin-Etsu Chemical Co., Ltd.) and 700 parts by weight of tetrahydrofuran were dispersed and mixed using a ball mill. Then, a charge transport layer coating solution was prepared. After coating the charge transport layer coating solution on the upper layer of the charge generation layer by dipping, by heating and drying at 130 ° C. for 30 minutes, a charge transport layer having a thickness of 18 μm is formed, The electrophotographic photosensitive member for dry development of Example 2 (stacked type) was obtained.

[Examples 3 to 16]
In Examples 3 to 16, as shown in Table 1, the sealing conditions (sealing temperature and sealing time) of the anodized film in Example 1 or Example 2 were changed, and the size and depth of the microcracks were changed. The electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 1 or Example 2 except that the above was changed.

[ Comparative Examples 1 to 10 and 12 to 15 ]
In Comparative Examples 1 to 10 and 12 to 15 , as shown in Table 1, by changing the sealing conditions (sealing temperature and sealing time) of the anodic oxide film in Example 1 or Example 2, microcracks were respectively formed. An electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 1 or Example 2 except that it was not generated.

[Example 17]
(1) Preparation of electrophotographic photosensitive member (single layer type) for wet development (1) -1 Preparation of an aluminum base tube provided with an anodic oxide film As in Example 1, the aluminum base tube has microcracks. An anodized film was formed.

(1) -2 Formation of Photosensitive Layer In the same manner as in Example 1, a single layer type photoreceptor was prepared to obtain an electrophotographic photoreceptor for wet development (single layer type).

(2) Evaluation The obtained electrophotographic photoreceptor for wet development (single layer type) was mounted on a copier Creation 7340 (manufactured by Kyocera Mita Co., Ltd.) modified for wet development, and in the same manner as in Example 1, Under H / H environmental conditions (35 ° C., 85% RH), 10,000 sheets of A4 paper were continuously printed, and the occurrence of black spots was evaluated.
Further, in continuous printing using the electrophotographic photosensitive member for wet development (single layer type), the charge amount was set to 1000 V, the developing bias was set to 850 V, and the light amount was set to 1.4 μJ / cm ² .
The obtained results are shown in Table 2.

[Examples 18 to 25]
In Examples 18 to 25, as shown in Table 2, wet electrophotographic photoreceptors (single layer type) were prepared by changing the sealing conditions of the anodic oxide film and the formation conditions of the microcracks. Each was evaluated as an electrophotographic photoreceptor for wet development in the same manner as in No. 17. The obtained results are shown in Table 2.

[Comparative Examples 16 to 22]
In Comparative Examples 16 to 22, as shown in Table 2, while changing the sealing conditions of the anodic oxide film, wet electrophotographic photoreceptors (single layer type) were prepared without causing microcracks, and the same as in Example 17 Each was evaluated as an electrophotographic photoreceptor for wet development. The obtained results are shown in Table 2.

According to the electrophotographic photosensitive member, the method of manufacturing the electrophotographic photosensitive member of the present invention, and the image forming apparatus provided with the electrophotographic photosensitive member, a simple technique is obtained by forcibly generating a predetermined crack in the anodic oxide film. Even so, the occurrence of black spots and the like can be effectively prevented.
Therefore, it can contribute to speeding up and high performance of the electrophotographic photosensitive member.

(A)-(b) is a figure provided in order to demonstrate the micro crack formed in the surface of the anodic oxide film of a drum base tube. (A)-(c) is a figure provided in order to demonstrate the basic structure and modification of a single layer type electrophotographic photoreceptor. (A)-(b) is a figure provided in order to demonstrate the basic structure and modification of a laminated type electrophotographic photosensitive member. It is a figure provided in order to demonstrate the relationship between the thickness of an anodic oxide film, and crack generation temperature. It is a figure provided in order to demonstrate the relationship between the electrolysis voltage at the time of forming an anodic oxide film, and crack generation temperature. It is a figure provided in order to demonstrate the relationship between the electrolysis temperature at the time of forming an anodic oxide film, and a crack generation temperature. It is a figure provided in order to demonstrate the relationship between the sealing time of an anodic oxide film, and crack generation temperature. It is a figure provided in order to demonstrate the relationship between the sealing temperature of an anodic oxide film, and the sealing degree of an anodic oxide film. It is a figure provided in order to demonstrate the relationship between the sealing time of an anodized film, and the sealing degree of an anodized film. FIG. 2 is a diagram for explaining an image forming apparatus including an electrophotographic photosensitive member.

Explanation of symbols

10: Single layer type electrophotographic photosensitive member 11: Photosensitive layer 11a: Undercoat layer 11b: Protective layer 11c: Charge generation layer 11d: Charge transport layer 12: Anodized film 12a: Micro crack 13: Drum base tube 20: Multilayer type Electrophotographic photoreceptor 50: Image forming apparatus

Claims (9)

An electrophotographic photoreceptor comprising a drum base tube having an anodized film provided on the surface of a conductive support, and a photosensitive layer formed around the drum base tube,
While setting the thickness of the anodic oxide film to a value within the range of 4 to 12 μm,
Microcracks having a depth in the range of 0.8 to 3 μm are formed on the surface of the anodic oxide film in the range of 3 to 20 per area of 254 mm × 10 mm on the surface of the photosensitive layer ,
The electrophotographic photosensitive member is characterized in that the photosensitive layer is formed on the anodic oxide film in a state where the microcracks are formed . 2. The electrophotographic photosensitive member according to claim 1 , wherein the ten-point average surface roughness (Rz) of the anodic oxide film is set to a value within a range of 0.1 to 0.3 [mu] m. 3. The electrophotographic photosensitive member according to claim 1, wherein a sealing degree (Y ₅ ) of the anodized film measured in accordance with JIS H8863 is set to a value of 80 μS or less. The electrophotographic photosensitive member according to claim 1 , wherein the photosensitive layer is a single layer type. 5. The electrophotographic photosensitive member according to claim 1 , wherein the photosensitive layer is a laminated type, and includes an undercoat layer between the drum base tube and the photosensitive layer. 6. . 6. The electrophotographic photosensitive member according to claim 1 , wherein the thickness of the photosensitive layer is set to a value within a range of 1 to 30 [mu] m. The electrophotographic photosensitive member according to any one of claims 1 to 6 , wherein the electrophotographic photosensitive member is a dry developing electrophotographic photosensitive member or a wet developing electrophotographic photosensitive member. A method for producing an electrophotographic photoreceptor comprising a drum base tube having an anodized film provided on the surface of a conductive support, and a photosensitive layer formed around the drum base tube,
Forming the anodic oxide film so as to have a thickness within a range of 4 to 12 μm ;
When the temperature at the time of sealing the anodic oxide film is less than 60 to 80 ° C., the sealing time is set to a value within the range of 8 to 60 minutes, and the temperature at the time of sealing processing is 80 to 95. In the case of ° C., by setting the sealing treatment time to a value within the range of 1 to 25 minutes, the microcracks whose depth is within the range of 0.8 to 3 μm on the surface of the anodized film, respectively. Forming within a range of 3 to 20 per area of 254 mm × 10 mm on the photosensitive layer surface ;
Forming a single layer type or a laminated type photosensitive layer;
A process for producing an electrophotographic photoreceptor, comprising: An image forming apparatus comprising the electrophotographic photosensitive member according to claim 1 .

Images