JP3047509B2 - Manufacturing method of electrophotographic photoreceptor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an electrophotographic photosensitive member used in an electrophotographic apparatus such as a copying machine or a printer, and more particularly, to a method for manufacturing a conductive substrate made of aluminum or an aluminum alloy under water. After washing, the conductive substrate is immersed in warm water, the conductive substrate is pulled up from the warm water, drained and dried, and then at least a binder resin and a photosensitive material are dissolved in a solvent on the conductive substrate. Alternatively, the present invention relates to a method for producing an electrophotographic photosensitive member in which a photosensitive layer is formed by applying a dispersed photosensitive layer coating solution.

[0002]

2. Description of the Related Art Conventionally, in manufacturing an electrophotographic photosensitive member used for an electrophotographic apparatus such as a copying machine or a printer, a photosensitive layer is generally formed on a conductive substrate made of aluminum or the like. I was

Here, since a conductive substrate used for manufacturing an electrophotographic photosensitive member is generally manufactured through a mechanical process, dust, dirt, metal particles, and the like are formed on the conductive substrate.
Foreign matter such as rust and oil is adhered. If the photosensitive layer is formed without removing it sufficiently, a defect occurs in the formed photosensitive layer, and an image is formed by using the electrophotographic photosensitive member manufactured as described above. When the formation is performed, there is a problem that an image to be formed has an image defect, and that the electrophotographic photosensitive member has a cleaning failure.

For this reason, conventionally, when a photosensitive layer is formed on a conductive substrate, the conductive substrate is washed and dust, dirt, metal particles,
Foreign substances such as rust and oil were removed. Here, in cleaning the conductive substrate as described above, conventionally, a solvent such as Freon or 1,1,1-trichloroethane has generally been used as the cleaning liquid.

However, when these solvents are released into the atmosphere, they tend to be internationally regulated as harming the earth's environment, such as destruction of the ozone layer in the stratosphere. A method for cleaning the above-mentioned conductive substrate without using the same has been studied.

In recent years, as a method of cleaning a conductive substrate without using a solvent as described above, a cleaning method using an alternative fluorocarbon, a chlorine-based solvent, an organic solvent, an aqueous detergent or the like has been developed. Reached.

[0007] However, the use of alternative chlorofluorocarbons or chlorinated solvents poses a problem of environmental destruction as in the case of the use of the above-mentioned chlorofluorocarbons and the like. However, it cannot be used for cleaning a conductive substrate for a long period of time, and when an organic solvent is used, the organic solvent is generally flammable, and thus there is a problem that the cleaning operation involves danger.

[0008] For this reason, in recent years, a method of washing a conductive substrate in an aqueous system using an aqueous detergent has attracted attention.
Various developments have been made on the aqueous detergent used and its cleaning method.

Here, when the conductive substrate is washed in an aqueous system using a water-based detergent as described above, selection of a detergent to be used, draining and drying of the conductive substrate after washing, and washing and cleaning after washing are performed. Although wastewater treatment and the like pose a problem, in particular, since draining and drying of the conductive substrate after washing has a large effect on the conductive substrate, various studies have been made on the method.

As a method of draining and drying the conductive substrate as described above, a solution adhering to the surface of the cleaned conductive substrate is replaced with a solvent such as chlorofluorocarbon, isopropyl alcohol, or 5-fluoropropanol. And replace
There are a method of drying this, a method of pulling the washed conductive substrate in high-temperature hot water, and drying while pulling it up. However, when the solution adhering to the surface of the cleaned conductive substrate is replaced with a solvent such as a substitute for chlorofluorocarbon, the case where the conductive substrate is cleaned with the use of a substitute for chlorofluorocarbon or the like is used as described above. Since a similar problem occurs, in recent years, the hot water pulling method tends to be used.

Here, when the conductive substrate washed in a water system as described above is drained and dried by a hot water pulling method, the higher the temperature of the hot water, the better the draining efficiency. The substrate was immersed in pure water at a temperature of about 80 ° C., and was gradually pulled up to drain and dry the conductive substrate.

However, a coating solution for a photosensitive layer obtained by dissolving or dispersing a binder resin or a photosensitive material in a solvent is applied to the conductive substrate which has been drained and dried by the hot water pulling method. When a photosensitive layer is formed, a large number of pinhole-shaped noises are generated in the photosensitive layer formed on the conductive substrate, or uneven coating or aggregation occurs on the photosensitive layer. When an image is formed, noise such as black and white spots is generated in the formed image, and there is a problem that the image quality is deteriorated.

[0013]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems in producing an electrophotographic photosensitive member used for an electrophotographic apparatus such as a copying machine or a printer. .

That is, in the present invention, after the conductive substrate made of aluminum or aluminum alloy is washed in an aqueous system, the conductive substrate is immersed in warm water, and the conductive substrate is pulled up from the warm water. After draining and drying, and then applying a coating solution for a photosensitive layer in which at least a binder resin and a photosensitive material are dissolved or dispersed in a solvent to form a photosensitive layer, the conductive substrate In the case where an image is formed using this electrophotographic photoreceptor, it is possible to suppress the occurrence of pinhole-shaped noise in the photosensitive layer formed on the photosensitive layer, or to suppress the occurrence of coating unevenness or aggregation in the photosensitive layer. It is another object of the present invention to stably obtain a good image without generating noise such as black and white spots on a formed image.

[0015]

According to the present invention, in order to solve the above-described problems, a conductive substrate made of aluminum or an aluminum alloy is washed in an aqueous system, and then the conductive substrate is heated in hot water. Immersed in the water, drained and dried the conductive substrate from the warm water,
In order to form a photosensitive layer by applying a coating solution for a photosensitive layer in which at least a binder resin and a photosensitive material are dissolved or dispersed in a solvent on the conductive substrate, the above-mentioned drainage drying is performed. The substrate was treated with a solvent used for the photosensitive layer coating liquid or a solvent compatible with the photosensitive layer coating liquid, and then the photosensitive layer coating liquid was applied on the conductive substrate. It is.

Here, as a method for cleaning the conductive substrate in an aqueous system, a conventionally known method can be used. For example, water cleaning using pure water, ionic, non-ionic Cleaning with a solution using a water-soluble surfactant, emulsion cleaning using a detergent in which a hydrocarbon solvent, higher alcohols, etc. are emulsified in water, chemical cleaning such as chemical etching cleaning, and applying a brush to a conductive substrate. It can be used in combination with physical cleaning such as brush scraping for pressing and cleaning, jet spray cleaning for jetting water at high pressure toward a conductive substrate, ultrasonic cleaning using ultrasonic waves, and megasonic scraping. it can.

As a specific method of washing the conductive substrate in an aqueous system, for example, the conductive substrate is washed with an emulsifier to remove oil stains and organic stains on the conductive base, The conductive substrate is rinsed with water to remove the emulsifier adhering to the conductive substrate, and then the conductive substrate is precision-cleaned using a surfactant solution or an etching solution to remove organic substances adhering to the conductive substrate. After completely removing dirt and inorganic contaminants, the conductive substrate is rinsed with water to remove a surfactant and an etchant attached to the conductive substrate. In the above, the above physical cleaning is performed in combination.

After washing the conductive substrate in an aqueous system as described above, the conductive substrate is immersed in warm water,
When the conductive substrate is pulled up from the warm water and drained and dried, it can be performed under the same conditions as those conventionally used. Usually, the temperature is raised to about 80 ° C. using pure water. Then, the conductive substrate washed under the aqueous system as described above is immersed in pure water at such a high temperature, and is gradually pulled up to drain and dry the conductive substrate.

Before applying the coating solution for a photosensitive layer in which a binder resin or a photosensitive material is dissolved or dispersed in a solvent to the conductive substrate thus dried and dried, the conductive substrate is coated with the photosensitive layer. The treatment is carried out using the solvent used for the coating solution or a solvent compatible with the coating solution for the photosensitive layer.

Here, the solvent compatible with the photosensitive layer coating liquid may be mixed with the photosensitive layer coating liquid at an arbitrary ratio, even if the binder resin precipitates or disperses in the photosensitive layer coating liquid. Means a solvent that does not cause a sharp drop in

In treating the conductive substrate that has been drained and dried using the above-mentioned solvent, the conductive substrate that has been drained and dried as described above is immersed in the above-mentioned solvent, or the above-mentioned solvent is removed. A known method such as application to a conductive substrate by spraying, or application of the solvent to a conductive substrate using a blade can be used. When the conductive substrate is immersed in the above-mentioned solvent for treatment, the immersion time is usually 5 seconds to 3 minutes, preferably 10 seconds to 1 minute, and the temperature is 20 to 30 ° C.
In addition, it is preferable to perform a treatment using an ultrasonic wave, a brush, a sponge, or the like at the time of immersion.

Then, the conductive substrate thus drained and dried is treated with the solvent used for the coating solution for the photosensitive layer or a solvent compatible with the coating solution for the photosensitive layer, and then the photosensitive layer is coated on the conductive substrate. A photosensitive coating layer is formed on the conductive substrate by applying a coating liquid for use.

[0023]

After washing the conductive substrate made of aluminum or aluminum alloy in an aqueous system as described above, the conductive substrate is immersed in warm water, the conductive substrate is pulled up from the warm water, drained and dried. After that, the conductive substrate is treated with a solvent used for the coating solution for the photosensitive layer or a solvent compatible with the coating solution for the photosensitive layer. When the layer is formed, there is no occurrence of pinhole-shaped noise in the formed photosensitive layer or uneven coating or aggregation of the photosensitive layer. When the image is formed in this manner, noise such as black and white spots does not occur in the formed image.

[0024]

EXAMPLES Hereinafter, a method for manufacturing an electrophotographic photosensitive member according to an embodiment of the present invention will be described in detail, and a comparative example will be described. It is clarified that it is superior to the electrophotographic photosensitive member manufactured by the method of (1).

(Examples 1 to 4) In these examples, the conductive substrate was formed of a JIS6063 aluminum alloy into a cylindrical shape having a diameter of 80 mm and a length of 340 mm, and the outer peripheral surface thereof was mirror-finished. It was made to use what was done.

Then, the conductive substrate is pre-cleaned for 1 minute by using a detergent (Pine Alpha ST-100S, manufactured by Arakawa Chemical Co., Ltd.) and spray cleaning and brush cleaning are performed, and then the conductive substrate is showered. Washing and brush washing were combined and rinsed with water for 30 seconds.

Next, the above-mentioned conductive substrate was immersed in a detergent (DK Beaclear CW-5520, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), and the main cleaning was performed for 1 minute by combining brush cleaning and ultrasonic cleaning. Then, the conductive substrate thus completely washed is immersed in pure water (1 μS / cm) and subjected to ultrasonic cleaning for 30 seconds, and thereafter, the conductive substrate is subjected to shower cleaning using pure water for 10 seconds. However, this operation was repeated twice.

Next, the conductive substrate thus washed in an aqueous system is immersed in pure water at a temperature of 80 ° C., and then the conductive substrate is removed from the pure water by 10 mm / sec.
It was pulled up at the speed of c and drained and dried.

Then, the conductive substrate dried and drained as described above is mixed with a solvent in which cyclohexanone and methyl ethyl ketone (MEK) are mixed in a ratio of 6: 4 in Example 1, and MEK in Example 2 is mixed. In a solvent, in Example 3, methyl isobutyl ketone (MIBK)
In Example 4, in a solvent of dichloromethane in Example 4, while rotating each conductive substrate, a nylon sponge was brought into contact with the surface of each conductive substrate to be treated for 30 seconds. The conductive substrate was taken out of each of the above solvents.

Each of the conductive substrates thus taken out was combined with 1 part by weight of a bisazo pigment shown in Chemical Formula 1, 1 part by weight of polyester (V-200, manufactured by Toyobo Co., Ltd.), and 50 parts by weight of cyclohexanone. , And 48 parts by weight of MEK, was immersed in a coating liquid for a charge generation layer, and a charge generation layer having a thickness of about 0.3 μm was formed on each conductive substrate by a dip coating method.

[0031]

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The presence of pinhole-shaped noise in the charge generation layer was examined by visually checking the charge generation layer thus formed on each conductive substrate. No pinhole-like noise was found. In Examples 1 to 4, each solvent in which the conductive substrate was immersed before forming the charge generation layer was compatible with the coating solution for the charge generation layer.

Next, 13 parts by weight of a distyryl derivative represented by the following structural formula (Formula 2) as a charge transporting material is provided on each of the conductive substrates on which the charge generating layer is formed as described above.
Polycarbonate resin (K-1300, manufactured by Teijin Chemicals Limited)
13 parts by weight of a charge transporting layer coating solution in which 87 parts by weight of dichloromethane was dissolved was applied by a dip coating method, and dried to form a film having a thickness of 20 μm on the charge generating layer of each conductive substrate. A charge transport layer was formed.

[0034]

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Comparative Example 1 In this comparative example, the same operation as in Examples 1 to 4 was performed until the conductive substrate was drained and dried. And in this comparative example, without treating the drained and dried conductive substrate with a solvent,
A charge generation layer was formed on the conductive substrate as it was in the same manner as in Examples 1 to 4.

When the state of the charge generation layer thus formed on the conductive substrate was visually observed, in this comparative example, pinhole-shaped noise was generated in the formed charge generation layer. Was.

After forming the charge generation layer on the conductive substrate in this manner, a charge transport layer was formed on the charge generation layer in the same manner as in Examples 1-4.

Comparative Example 2 In this comparative example, the operation was the same as in Examples 1 to 4 until the conductive substrate was drained and dried. In the comparative example, the drained and dried conductive substrate was immersed in isopropyl alcohol incompatible with the above-described charge generation layer coating liquid. As in the case of 4, while rotating the conductive substrate, a nylon sponge is brought into contact with the surface of the conductive substrate to obtain a sponge.
After the treatment for 2 seconds, the conductive substrate was taken out of the solvent, and then the above Examples 1-4 were placed on the conductive substrate.
The charge generation layer was formed in the same manner as in the above case.

Here, when the state of the charge generation layer formed on the conductive substrate in this manner was visually observed, in the case of this comparative example, coating unevenness and aggregation occurred in the formed charge generation layer. I was

After forming the charge generation layer on the conductive substrate in this manner, a charge transport layer was formed on the charge generation layer in the same manner as in Examples 1 to 4.

(Examples 5 and 6) In these examples, the operations were the same as those in Examples 1 to 4 until the conductive substrate was drained and dried. Then, each of the conductive substrates thus drained and dried is immersed in a solvent of tetrahydrofuran in Example 5, and in a solvent of dichloromethane in Example 6, respectively, and the same as in Examples 1 to 4 described above. Then, while rotating each conductive substrate, a nylon sponge was brought into contact with the surface of each conductive substrate and treated for 30 seconds, and then each conductive substrate was taken out of the solvent.

Next, each conductive substrate treated with the solvent as described above was mixed with 1 part by weight of a phthalocyanine pigment, 1 part by weight of a polyvinyl butyral resin, and 98 parts of tetrahydrofuran.
The resultant was immersed in a coating solution for a charge generation layer to which a part by weight was added, and a charge generation layer having a thickness of about 0.2 μm was formed on each conductive substrate by a dip coating method.

When the charge generation layers thus formed on each conductive substrate were visually observed, no pinhole-shaped noise was found in any of the charge generation layers. In these Examples 5 and 6, each solvent in which the conductive substrate was immersed before forming the charge generation layer was:
It had compatibility with the above-mentioned coating solution for charge generation layer.

After the formation of the charge generation layers on the respective conductive substrates in this manner, the charge transport layers were formed on the respective charge generation layers in the same manner as in Examples 1 to 4.

Comparative Example 3 In this comparative example, the operation was the same as in Examples 1 to 4 until the conductive substrate was drained and dried. And in this comparative example, without treating the drained and dried conductive substrate with a solvent,
A charge generation layer was formed on the conductive substrate as it was in the same manner as in Examples 5 and 6.

When the state of the charge generation layer thus formed on the conductive substrate was visually observed, in the comparative example, pinhole-shaped noise was generated in the formed charge generation layer. Was.

After forming the charge generation layer on the conductive substrate in this manner, a charge transport layer was formed on the charge generation layer in the same manner as in Examples 1 to 4.

Next, Example 1 manufactured as described above was used.
6 and Comparative Examples 1 to 3, images were formed, and image noise in the formed images was evaluated. The results are shown in Table 1 below. In performing the image formation, the electrophotographic photosensitive members of Examples 1 to 4 and Comparative Examples 1 and 2 were mounted on a commercially available copying machine (EP-5400, manufactured by Minolta Camera Co., Ltd.). , 6 and Comparative Example 3 were manufactured using a commercially available reader printer (RP5, manufactured by Minolta Camera Co., Ltd.).
07) to form an image.

[0049]

[Table 1]

[0050]

As described above in detail, in the method of manufacturing an electrophotographic photoreceptor according to the present invention, a conductive substrate made of aluminum or an aluminum alloy is washed in an aqueous system, and then the conductive substrate is washed. The conductive substrate is pulled up from the warm water by immersion in warm water, and the conductive substrate is drained and dried. Then, the conductive substrate is compatible with the solvent used for the photosensitive layer coating liquid or the photosensitive layer coating liquid. After treating with a solvent, the photosensitive layer was formed by applying a coating solution for a photosensitive layer on the conductive substrate, so that pinhole-shaped noise was generated in the formed photosensitive layer, The occurrence of uneven coating, aggregation and the like is eliminated.

As a result, when an image was formed using the electrophotographic photosensitive member manufactured by the method according to the present invention,
A good image can be stably obtained without generating noise such as black and white spots on the formed image.

Continuation of the front page (56) References JP-A-3-163558 (JP, A) JP-A-4-242747 (JP, A) JP-A-58-37173 (JP, A) JP-A-4-218056 (JP, A) JP-A-4-97158 (JP, A) JP-A-1-312554 (JP, A) JP-A-4-81861 (JP, A) JP-A-3-29959 (JP, A) JP-A Sho 58-14841 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) G03G 5/05

Claims (1)

(57) [Claims] After washing a conductive substrate made of aluminum or an aluminum alloy in an aqueous system, the conductive substrate is immersed in warm water, the conductive substrate is pulled up from the warm water, drained and dried, On the conductive substrate, a coating solution for a photosensitive layer in which at least a binder resin and a photosensitive material are dissolved or dispersed in a solvent is applied to form a photosensitive layer. On the conductive substrate using a solvent used for the photosensitive layer coating solution or a solvent compatible with the photosensitive layer coating solution, and then applying the photosensitive layer coating solution on the conductive substrate. A method for manufacturing an electrophotographic photoreceptor, comprising: