JPH11271993A - Apparatus and method for manufacturing electrophotographic photosensitive member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the thickness of a photosensitive liquid film formed on a lower end portion of a substrate and to suppress the thinning of the upper part of the photosensitive layer film due to liquid dripping. SOLUTION: In a method of manufacturing a photoreceptor for electrophotography by applying a pigment dispersion photosensitive liquid to a substrate by a dip coating method, a voltage is applied to the substrate when the substrate is pulled up from the photosensitive liquid and applied. Controls the thickness of the coating formed on it.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an electrophotographic photosensitive member by a dip coating method and a production apparatus for use in the method.

[0002]

2. Description of the Related Art An electrophotographic photosensitive member is generally manufactured by a dip coating method.

Since this method can be applied to an arbitrary shape, it is an excellent manufacturing method in that a coating film having a constant thickness can be formed on the surface of a substrate of an electrophotographic photosensitive member having a cylindrical shape, for example. However, since the substrate is immersed in the photosensitive solution and then withdrawn from the photosensitive solution for application, a coating film is formed on all the immersed portions. However, since both ends of the base are in contact with peripheral parts such as a developing machine, when a cylindrical electrophotographic photoreceptor is used by attaching it to an OA device such as a printer or a copier, It is preferable that the substrate is exposed without adhering the liquid.

In the dip coating method, the substrate is immersed in a closed state in order to prevent the photosensitive solution from entering the inside of the substrate. The photosensitive liquid penetrates to a certain depth inside the substrate due to the influence of the liquid pressure, and a photosensitive layer is formed on the inner surface of the lower end of the substrate. However, it is necessary that the inner surface of the base is not coated with a photosensitive layer in order to perform a conduction treatment with the device and improve the engagement with the device.

Therefore, conventionally, an electrophotographic photoreceptor has been manufactured by dip-coating a substrate with a photosensitive solution and then removing unnecessary portions of the photosensitive layer applied to the lower end of the substrate and the inner surface of the lower end. As a method of removing the coating film, a method of washing the coating film formed on the inner surface of the base with an organic solvent (Japanese Patent Publication No. 4-7377)
No. 8), a method of drying a coating film and removing it with an organic solvent (Japanese Patent Application Laid-Open No. 4-214566), and an apparatus for removing the coating film formed on the lower end portion of the substrate and the inner surface of the lower end portion with an organic solvent (Japanese Patent Application Laid-Open No. HEI 4-214566). A method of removing a coating film of a photosensitive layer using an organic solvent is known as disclosed in Japanese Unexamined Patent Publication No. Hei.

[0006]

However, these methods require an additional device for removing unnecessary coatings of the photosensitive layer, resulting in an increase in production cost and a decrease in production capacity. Further, in the dip coating method, there is an inherent problem that liquid dripping occurs when the substrate is pulled out of the photosensitive liquid, and the thickness of the coating on the top of the coating film becomes thin, so that the coating cannot be applied to a uniform thickness throughout the coating film. Therefore, it has been necessary to optimize and cope with many manufacturing conditions such as the type and viscosity of the solvent constituting the photosensitive solution and the speed of pulling up the substrate.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems, and it is an object of the present invention to provide a method of manufacturing an electrophotographic photosensitive member by a dip coating method. The thickness of the coating that adheres to the lower end of the base and the inner surface of the lower end, which is in contact with the part, is reduced, and furthermore, substantially no coating is formed, and the upper part of the coating is thinned by liquid dripping It is an object of the present invention to provide a manufacturing apparatus and a manufacturing method for preventing such a situation.

The invention according to claim 1 is an apparatus for manufacturing an electrophotographic photosensitive member having means for dip-coating a pigment dispersion photosensitive liquid on a substrate and means for applying and controlling a voltage to the substrate. .

According to a second aspect of the present invention, there is provided a method for producing a photoreceptor for electrophotography by applying a pigment-dispersed photosensitive liquid to a substrate by a dip coating method. A method for producing a photoconductor for electrophotography, comprising applying a voltage to control the thickness of a coating film of a pigment-dispersed photosensitive liquid formed on a substrate.

According to a third aspect of the present invention, a voltage is applied,
The control of the thickness of the coating film of the pigment-dispersed photosensitive liquid formed on the substrate is performed by applying a voltage having the same sign as the charging of the coated film when pulling the lower end of the substrate from the pigment-dispersed photosensitive liquid. 3. The method according to claim 2, wherein the thickness of the film is reduced.

According to a fourth aspect of the present invention, the absolute value of the electric field intensity generated by the voltage applied to the lower end of the base is 5 to 1
4. The method according to claim 3, wherein the pressure is 000 V / cm.

According to a fifth aspect of the present invention, a voltage is applied,
Control of the thickness of the coating film of the pigment-dispersed photosensitive solution formed on the substrate is performed by pulling the substrate portion on which the coated film is formed from the pigment-dispersed photosensitive solution, by applying a voltage having the opposite sign to the charge of the coating film. 3. The method according to claim 2, wherein the application is performed to suppress the thinning of the upper part of the coating film.

According to a sixth aspect of the present invention, the absolute value of the electric field intensity generated by the voltage applied to the upper end of the base is 5 to 1
6. The method according to claim 5, wherein the pressure is 000 V / cm.

The invention according to claim 7 is the production method according to claims 3, 4, 5, or 6, wherein the pigment is a phthalocyanine pigment.

The invention according to claim 8 is the production method according to claim 7, wherein the phthalocyanine pigment is a metal-free phthalocyanine pigment.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention uses a dip coating method
In a method of manufacturing a photoreceptor for electrophotography by applying a pigment-dispersed photosensitive liquid to a substrate, a voltage is applied to the substrate when the substrate is pulled up from the photosensitive liquid and applied, and a pigment-dispersed photosensitive liquid formed on the substrate is applied. A method for producing an electrophotographic photoconductor, comprising controlling the thickness of a coating film of a liquid. As a result, by the dip coating method, the thickness of the coating film formed up to the lower end portion of the base and the inner surface of the lower end portion is reduced, and furthermore, the coating film is substantially prevented from being formed, and the liquid dripping occurs. Thinning of the upper part of the coating can be suppressed. Here, the upper end and the lower end of the base are OA such as a printer and a copier.
A part that comes into contact with peripheral parts when attached to equipment,
Generally, it is a portion within 3 cm from the edge of the base. On the other hand, the upper or lower part of the coating means the upper or lower part of the photosensitive layer coating formed when the substrate is pulled up by the dip coating method.

The production method of the present invention can be carried out using a production apparatus having means for dip-coating a photosensitive solution and means for applying and controlling a voltage to a substrate as shown in FIG. 1, for example.

The manufacturing apparatus shown in FIG.
And a voltage application control device 5. The application of the voltage from the voltage application control device 5 is performed via a jig or the like supporting the base. The counter electrode 6, a device for holding the substrate, a substrate elevator for dipping or pulling the substrate into the coating tank, a sensor for monitoring the position of the substrate, and positional information obtained from the sensor, if necessary. In addition, a device or the like for controlling the voltage can be provided. The horizontal distance between the base and the counter electrode or the coating tank preferably has a function of maintaining uniform so as to prevent the electric field intensity from being different depending on the part of the base. The voltage application timing can be controlled by a signal from the above-described sensor, but the position of the base is calculated from the motor driving time and pulling speed obtained from the input signal of the base driving motor, and the voltage is calculated. The method of controlling the position to which is applied is simple, and it is preferable to provide such means.

The coating tank 4 is a tank for holding a photosensitive solution containing a pigment, and immerses the substrate to dip-coat the photosensitive solution. The shape and size of the coating tank are not particularly limited, but when processing one substrate in the coating tank, a cylindrical shape is used, and when processing a plurality of substrates, a square prism is used. This is preferable in that the production becomes easy. The size of the coating tank is not particularly limited, but depends on the size of the substrate to be treated. The material of the coating tank is not particularly limited, but may be any as long as it can hold the photosensitive solution. When a voltage is applied to the coating tank, the coating tank is preferably grounded, and the material of the coating tank needs to be a conductive material. In addition, when a voltage is applied between the electrode and the counter electrode, the coating tank does not necessarily need to be grounded, and the material of the coating tank is not limited to a conductive material.

The voltage application control device 5 is a device for applying a voltage to the base 1. Voltage can also be applied from this device via a jig supporting the base. In such a case, the support jig needs to be conductive. The absolute value of the electric field intensity generated by the voltage applied to the substrate is 5
It is preferable that the absolute value of the voltage is 0.5 to 5000 V when the distance between the base and the counter electrode is 0.1 to 5.0 cm.

The counter electrode 6 may be provided in the coating tank, and a voltage may be applied to the base between the counter electrode and the counter electrode. If the counter electrode is not provided, the coating tank plays the role of the counter electrode. When the counter electrode is provided, the distance from the base can be easily reduced, and the absolute value of the voltage applied to the base itself can be reduced. The distance between the base and the counter electrode differs depending on the applied voltage and is not particularly limited. However, the distance between the base and the counter electrode is preferably 2 to 8 mm from the viewpoint that the distance from the base can be easily maintained uniformly.

The shape of the counter electrode 6 is not particularly limited, but is preferably similar to the shape of the substrate in order to keep the distance to the substrate uniform. Since the base is usually cylindrical, the counter electrode is also preferably cylindrical. The size of the counter electrode is not particularly limited, and varies depending on the size of the substrate to be treated.
It is preferable that the distance is larger by about 16 mm because the distance between the base and the counter electrode is easily maintained uniformly. The length of the counter electrode does not necessarily need to be longer than the length of the base, but it should be at least such that the liquid surface of the photosensitive liquid is present in the counter electrode at the time of immersion and withdrawal of the base. Is preferred. Although it is necessary that the material has conductivity, it is preferable to use SUS because rust does not occur. Further, it is preferable that the counter electrode is grounded.

The position of the counter electrode 6 is not particularly limited. However, it is preferable that the counter electrode 6 is provided at least at such a height that the liquid surface of the photosensitive liquid is present at the counter electrode at the time of immersion and withdrawal of the substrate. It is preferable that the horizontal distance between the counter electrode and the base is controlled so as to be uniform so that the electric field intensity generated by the applied voltage does not differ depending on the part of the base.

By arranging a plurality of counter electrodes in the coating tank, it becomes possible to simultaneously process a plurality of substrates. In addition, by providing a plurality of counter electrodes having different sizes, it is possible to simultaneously process a plurality of substrates having different sizes.

Preferred examples of the production apparatus include:
Examples include the following:

[0026] Cylindrical shape, diameter 3-30cm, length 20-
SUS coating tank 4 at 130 cm, voltage application control device 5 capable of applying a voltage of 0.5 V or more, jig made of conductive material supporting base, cylindrical shape, diameter 20 to 160 m
m, a length of 10 to 100 cm, a counter electrode 6 made of a conductive material, and the counter electrode 6 is installed in the coating tank 4 so that the horizontal distance between the base and the counter electrode is uniform. Further, it is preferable that at least one of the coating tank 4 and the counter electrode 6 is grounded.

The substrate 1 is usually a cylindrical shape made of an aluminum alloy, having a diameter of 20 to 160 mm and a length of 10 to 10 mm.
It has a size of about 0 cm. Electrophotographic photoreceptors include those in which a charge generation layer and a charge transport layer are sequentially laminated on a substrate, and those in which only a photosensitive layer is laminated on a substrate.

The photosensitive liquid 3 is a pigment-dispersed photosensitive liquid and is composed of a pigment, a binder resin, and a solvent.

As the pigment, various charge-generating materials having photoconductivity can be used, and there is no particular limitation. Pigments and polycyclic quinone pigments. These may be used alone or in combination of two or more. In particular, it is preferable to use a pigment having excellent photosensitivity to the exposure wavelength. Of these, phthalocyanine pigments are preferred in that they have photosensitivity to semiconductor laser light. Also, among phthalocyanine pigments,
A metal-free phthalocyanine-based pigment is particularly preferred because of its excellent light sensitivity. Here, the non-metallic phthalocyanine pigment has a chemical structure that does not include a metal atom in the phthalocyanine skeleton.

The binder resin functions to hold the above-mentioned charge generating material, and is not particularly limited, and examples thereof include a polyester resin, a polycarbonate resin, a polyvinyl butyral resin, an epoxy resin, and a polystyrene resin. Even if only one of these is used,
More than one species may be used in combination.

Although the solvent is not particularly limited, for example, methylene chloride, chloroform, THF, toluene, methyl ethyl ketone and the like are preferable. These may be used alone or in combination of two or more.

After the pigment, the binder resin, and the solvent are mixed, the mixture is vigorously stirred to disperse the pigment in the binder resin, thereby producing a photosensitive solution.

The content of the pigment in the photosensitive solution to be used is not particularly limited, but is preferably 5 to 30% (% by weight, hereinafter the same) from the viewpoint of realizing sufficient light sensitivity. Further, the content of the binder resin is preferably 70 to 95% from the viewpoint of sufficiently retaining the pigment.

Using such a substrate and the photosensitive solution, an electrophotographic photosensitive member is manufactured by a manufacturing apparatus having a means for dip-coating the photosensitive solution as described above and a means for applying and controlling a voltage to the substrate. Is done.

The pigment in the photosensitive liquid is generally charged, although the charge polarity and the charged voltage are different depending on the kind of the solvent constituting the photosensitive liquid and the kind of the resin. Using the charge of the pigment,
The thickness of the coating film can be controlled by applying a voltage to the substrate.

Here, the control of the thickness of the coating film means that, for example, when the coating film component is positively charged, a negative voltage is applied to the substrate to remove the pigment-containing coating film component on the substrate. Attracting, increasing the thickness of the coating, or applying a positive voltage to the substrate to remove coating components including pigment from the substrate to reduce the thickness of the coating, or to substantially reduce the thickness of the coating. Means to form a portion that is not formed on the substrate. Conversely, when the pigment is negatively charged, a positive voltage is applied to the base to attract the coating containing the pigment onto the base, thereby increasing the thickness of the coating, or This means that a negative voltage is applied to reduce the thickness of the coating film by removing the coating film components including the pigment from the substrate, or to form a portion where the coating film is not substantially formed.

In order to control the thickness of the coating film, not only the above-described method of controlling with the polarity of the voltage but also the method of controlling the electric field intensity generated by the applied voltage by changing the intensity of the electric field between the upper and lower portions of the coating film. Is also included. For example, when the pigment is positively charged, when the substrate is pulled out of the photosensitive solution, when the upper part of the coating reaches the surface of the photosensitive liquid, the electric field strength is set to be larger than that of the lower part of the coating. By increasing the thickness of the upper part of the coating film, it is possible to suppress the thinning of the upper part of the coating film caused by liquid dripping.

Since the control of the film thickness by the applied voltage is generally determined by a slight interface region between the contact surface of the photosensitive liquid surface and the substrate, the substrate immersed in the photosensitive solution and the substrate The influence of the interface portion with the photosensitive liquid in contact with the film thickness on the film thickness is small. Further, after being withdrawn from the photosensitive solution, the solvent evaporates and the coating film is fixed to the substrate, so that even if a voltage is applied to the substrate, the film thickness hardly changes.

The electrophotographic photosensitive member must be formed so that no coating film is formed on both ends of the substrate. The position where the voltage is applied so that the coating film is not formed is the photosensitive liquid,
It cannot be unconditionally determined because it depends on conditions such as the electric field strength. However, for example, from the time when the upper part of the portion where no coating film is formed 3 to 30 mm from the lower end of the base reaches the liquid level of the photosensitive solution until the base is completely pulled up. When a voltage is applied, the thickness of the coating at the lower end of the substrate can be reduced, or the coating can be substantially prevented from being formed.

In the dip coating method in which the substrate is immersed in the vertical direction, liquid dripping occurs when the substrate is pulled out of the photosensitive solution, and the upper part of the coating film tends to be thin. However, a voltage is applied to the substrate. This can also eliminate such thinning of the upper part of the coating film. In this case as well, the position at which the voltage is applied cannot be unconditionally determined because it depends on the photosensitive solution and the electric field strength.
Until the formation of the 0 mm coating is completed, applying a voltage can suppress the thinning of the upper portion of the coating.

Although the absolute value of the electric field intensity generated by the applied voltage is not particularly limited, it is preferably 5 to 1000 V / cm in order to show the influence of the treatment, and preferably 1 to 1000 V / cm.
More preferably, it is 0 to 100 V / cm. 5V /
cm, the effect of voltage application is small,
If it is larger than 000 V / cm, the effect of voltage application tends to be saturated. The electric field strength is
It does not need to be constant, and can be changed in consideration of various conditions.

The pulling speed is not particularly limited and depends on the coating film thickness and the pigment concentration.
It is preferably 0 to 130 cm / min. 10cm /
If the rate is less than 1 minute, the productivity is remarkably reduced, and if the rate is more than 130 cm / min, the thickness unevenness of the photosensitive layer tends to increase. The pulling speed does not need to be constant, and can be changed in consideration of various conditions.

The temperature of the photosensitive solution is not particularly limited.
20 because it is produced in a temperature-controlled clean room
It is preferable that the temperature be controlled within the range of -28 ° C.

Preferred specific examples of the production method include:
Examples include the following: Using a pigment-dispersed photosensitive liquid having a pigment content of 5 to 30% and a binder resin content of 70 to 95% using a metal-free phthalocyanine, a binder resin, and a solvent as the pigment, and a pulling speed of 10 to 10%.
At a voltage of 130 cm / min, a voltage is applied so that the electric field strength becomes 5 to 1000 V / cm from when the portion 3 to 30 mm from the lower end of the substrate reaches the liquid level of the photosensitive solution until the substrate is pulled up. This is a manufacturing method for reducing the thickness.

A pigment-dispersed photosensitive liquid having a pigment content of 5 to 30% and a binder resin content of 70 to 95% using a non-metallic phthalocyanine, a binder resin and a solvent as a pigment is used. The electric field strength was set at 130 cm / min, from the time when the substrate was started to be pulled up until the time when the formation of the coating film of 3 to 50 mm was completed, from 5 to 1000 V / c.
This is a production method in which a voltage is applied so as to be m, thereby suppressing the thinning of the coating film on the coating film.

The substrate on which the coating film is formed is then dried when the coating film is a thermoplastic resin, and cured when the coating film is a thermosetting resin, and is used as a photoreceptor for electrophotography. , Used in copiers and the like. The drying time and temperature may vary depending on the type of photosensitive solution used, but cannot be determined.
Minutes to 2 hours. On the other hand, the time and temperature for curing also vary depending on the photosensitive liquid used, etc.
220 ° C., 5 minutes to 10 hours. The thickness of the photosensitive layer after curing is preferably from 10 to 30 μm in order to obtain good electrophotographic properties.

A coating film is not substantially formed on the lower end portion of the substrate of the electrophotographic photosensitive member obtained by using the manufacturing apparatus and the manufacturing method of the present invention. Is controlled. In the conventional dip coating method,
It was necessary to optimize not only the conditions of the photosensitive solution such as the solvent and the viscosity, but also various production conditions such as the pulling speed of the substrate, but in the present invention, basically, only controlling the applied voltage requires more optimization. An electrophotographic photosensitive member having a uniform film thickness can be easily obtained.

[0048]

EXAMPLES Next, the present invention will be described based on examples, but the present invention is not limited to these examples.

Production Example 1 Metal-free phthalocyanine (Fastogen) was used as a pigment.
80 g of Blue 8120-BS, manufactured by Dainippon Ink and Chemicals, Inc .; polyester resin as binder resin (Vylon 20SS, manufactured by Toyobo Co., Ltd., solid content concentration: 30 wt% toluene / methyl ethyl ketone solution) 55
0 g, butylated melamine resin (Uban 20HS, manufactured by Mitsui Toatsu Chemicals, Inc.) 80 g, toluene 120 as a solvent
0 g and 300 g of methyl ethyl ketone.
A dispersion treatment was performed while stirring at 500 rpm for 1 hour to prepare a pigment dispersion type photosensitive solution.

Example 1 In a cylindrical coating tank 4 having a diameter of 10 cm and a depth of 45 cm,
A cylindrical counter electrode 6 having a diameter of 4.0 cm and a length of 3.0 cm was placed so that the counter electrode and the upper end of the coating tank were at the same height. When the photosensitive solution 3 prepared in Production Example 1 was poured into the coating tank 4, the liquid level reached 1.0 cm from the upper surface of the coating tank. The temperature of the photosensitive solution was 25 ° C. The coating tank and the counter electrode were both grounded.

Here, a cylindrical aluminum alloy substrate having a diameter of 3.0 cm and a length of 32 cm was placed at a constant speed of 60 cm / min so that the position 1.0 cm from the upper end of the substrate was not covered with the photosensitive liquid. It was lowered into the photosensitive solution and immersed for 2 seconds. The substrate was pulled out at a constant speed of 40 cm / min, and when the lower end of the substrate reached 1.0 cm from the surface of the photosensitive solution, a voltage of 250 V was applied to the substrate so that the electric field strength became +50 V / cm. Next, it was heated and cured at 150 ° C. for 2 hours to form a photosensitive layer on the substrate. Although the thickness of the coating film was 20 μm at the center of the coating film, almost no photosensitive layer was formed at the lower end of the substrate to which the voltage was applied. Therefore, in this case, it was not necessary to wipe the lower end portion of the base, and the electrophotographic photosensitive member could be manufactured.

The photosensitive layer was hardly formed on the inner surface of the lower end of the substrate.

Example 2 Using the same apparatus, substrate and photosensitive solution as in Example 1, immersion was carried out for 2 seconds so that the top of the substrate at a height of 1.0 cm was not covered with the photosensitive solution. The substrate is pulled up at a constant speed of 40 cm / min,
When the lower end of the substrate reached 1.0 cm from the liquid surface of the dispersion, a voltage of 25 V was applied to the substrate so that the electric field strength was +5 V / cm.

The photosensitive solution was slightly applied to the lower end of the substrate so as to be visually recognized. Considering the design of the photoreceptor drum,
As in the conventional method, the photosensitive layer at the lower end of the substrate is formed by applying fibers impregnated with toluene to the photosensitive layer and rotating the substrate at a speed of 1 m / min. I wiped it off. When the film thickness after curing is about 20 μm, about 1
A minute wiping operation is required. In this case, the photosensitive layer at the lower end of the substrate could be completely removed in a very short time of 2 seconds and about 1/30.

COMPARATIVE EXAMPLE 1 Using the same apparatus, substrate, and photosensitive liquid as in Example 1, the position was set at 1.0 cm from the upper end of the substrate so as not to be covered with the photosensitive liquid.
Soaked for seconds. The substrate was pulled up at a constant speed of 40 cm / min without applying a voltage.

Since the photosensitive liquid was applied to the lower end of the base, the wiping operation of the lower end of the base was performed under the same conditions as in Example 2. The wiping operation took a long time for about one minute.

Example 3 The same apparatus, substrate and photosensitive liquid as in Example 1 were used.
Soaked for seconds. When the substrate is pulled up at a constant speed of 40 cm / min, the liquid level immediately after the pulling is 2.
A voltage of -50 V / cm was applied until the 3 cm portion was reached, after which the voltage was reduced to zero.

Next, the photosensitive layer was cured by heating at 150 ° C. for 2 hours. When the film thicknesses of a portion 2.1 cm from the upper end of the substrate, a central portion, and a portion 2.1 cm from the lower end of the substrate were measured, the thickness of the photosensitive layer was 19.7 μm, 2
A coating film having a uniform thickness of 0.0 μm and 20.0 μm was formed.

COMPARATIVE EXAMPLE 2 The same apparatus, substrate and photosensitive liquid as in Example 1 were used so that 1.5 cm from the upper end of the substrate was not covered with the photosensitive liquid.
Soaked for seconds. The substrate was pulled up at a constant speed of 40 cm / min without applying a voltage.

Next, the photosensitive layer was cured by heating at 150 ° C. for 2 hours. When the film thicknesses of a portion 2.1 cm from the upper end of the substrate, a central portion, and a portion 2.1 cm from the lower end of the substrate were measured, 18.0 μm, 20.0 μm,
20.0 μm, and the upper part of the coating film became thin.

According to these examples, in the dip coating method, when a voltage is applied when the substrate is pulled up, the thickness of the coating film at the lower end of the substrate is reduced or the portion where the coating film is not substantially formed is formed. It can be seen that it is possible to suppress the formation of thin films on the upper surface of the coating film due to the liquid dripping.

[0062]

According to the manufacturing apparatus of the first aspect of the present invention,
It has a means for dip-coating the pigment-dispersed photosensitive solution on the substrate and a means for applying and controlling a voltage to the substrate, so that when pulling up the substrate from the photosensitive solution, a voltage is applied to the substrate and The thickness of the formed coating film can be controlled, and the productivity of the electrophotographic photoreceptor can be significantly improved.

In the production method according to the second aspect of the present invention, in a method of producing a photosensitive member for electrophotography by applying a pigment dispersion photosensitive liquid to a substrate by a dip coating method, the substrate is pulled up from the photosensitive liquid and coated. At this time, a voltage can be applied to the substrate to control the thickness of the coating film of the pigment dispersion type photosensitive liquid formed on the substrate, and the productivity of the electrophotographic photoreceptor can be significantly improved.

According to a third aspect of the present invention, in the method of producing a photosensitive member for electrophotography by applying a pigment dispersion photosensitive solution to a substrate by a dip coating method, the substrate is pulled up from the photosensitive solution and applied. At this time, a voltage having the same sign as the charging of the coating film is applied to reduce the thickness of the coating film at the lower end of the base.

According to a fourth aspect of the present invention, in the method for producing a photosensitive member for electrophotography by applying a pigment dispersion photosensitive liquid to a substrate by dip coating, the substrate is pulled up from the photosensitive liquid and coated. At this time, by setting the absolute value of the electric field intensity generated by the applied voltage to 5 to 1000 V / cm or more, the thickness of the coating film at the lower end portion of the base can be reduced.

According to a fifth aspect of the present invention, there is provided a method for producing a photosensitive member for electrophotography by applying a pigment-dispersed photosensitive liquid to a substrate by a dip coating method. At this time, it is possible to suppress the thinning of the upper part of the coating film by applying a voltage having the opposite sign to the charging of the coating film.

According to a sixth aspect of the present invention, in the method of producing a photosensitive member for electrophotography by applying a pigment dispersion photosensitive liquid to a substrate by dip coating, the substrate is pulled up from the photosensitive liquid and coated. At this time, by setting the absolute value of the electric field intensity generated by the applied voltage to 5 to 1000 V / cm or more, it is possible to suppress the thinning due to the liquid dripping on the upper part of the coating film.

According to a seventh aspect of the present invention, a phthalocyanine-based pigment is used as a pigment, and a voltage is applied to the substrate when the substrate is pulled up from the photosensitive solution and applied. The thickness of the liquid coating can be controlled,
The productivity of the electrophotographic photoreceptor can be significantly improved.

In the production method according to the eighth aspect of the present invention, a metal-free phthalocyanine is used as the phthalocyanine-based pigment, and when the substrate is pulled up from the photosensitive solution and applied, a voltage is applied to the substrate to disperse the pigment formed on the substrate. The thickness of the coating film of the system photosensitive solution can be controlled, and the productivity of the electrophotographic photosensitive member can be significantly improved.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of an apparatus for manufacturing an electrophotographic photosensitive member according to one embodiment of the present invention.

[Explanation of symbols]

1 substrate, 2 photosensitive layer, 3 photosensitive solution, 4 coating tank, 5
Voltage application control device, 6 Counter electrode, 7 Base upper end, 8
The lower end of the base.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Wei Nagae 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Inside Mitsubishi Electric Co., Ltd. (72) Takamitsu Fujimoto 2-3-2 Marunouchi 3-chome, Chiyoda-ku, Tokyo Rishi Electric Co., Ltd.

Claims (8)

[Claims] An apparatus for producing an electrophotographic photosensitive member, comprising: means for dip-coating a pigment-dispersed photosensitive liquid on a substrate; and means for applying and controlling a voltage to the substrate. 2. A method for producing a photoreceptor for electrophotography by applying a pigment-dispersed photosensitive liquid to a substrate by a dip coating method, wherein a voltage is applied to the substrate when the substrate is pulled up from the photosensitive liquid. A method for producing an electrophotographic photosensitive member, comprising controlling the thickness of a coating film of a pigment dispersion photosensitive liquid formed thereon. 3. A method for controlling the thickness of a coating film of a pigment dispersion photosensitive liquid to be formed on a substrate by applying a voltage, comprising: 3. The method according to claim 2, wherein the voltage of the same sign is applied to reduce the thickness of the coating film. 4. The method according to claim 3, wherein the absolute value of the electric field intensity generated by the voltage applied to the lower end portion of the base is 5 to 1000 V / cm. 5. A method for controlling the thickness of a coating film of a pigment dispersion-based photosensitive liquid formed on a substrate by applying a voltage, comprising: 3. The method according to claim 2, wherein a voltage having the opposite sign to the charging of the coating film is applied to suppress the thinning of the upper portion of the coating film. 6. The method according to claim 5, wherein the absolute value of the electric field intensity generated by the voltage applied to the upper portion of the coating film is 5 to 1000 V / cm. 7. The method according to claim 3, wherein the pigment is a phthalocyanine pigment. 8. The method according to claim 7, wherein the phthalocyanine pigment is a metal-free phthalocyanine pigment.